1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
4  * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
5  *
6  * Standard functionality for the common clock API.  See Documentation/driver-api/clk.rst
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/clk-provider.h>
11 #include <linux/clk/clk-conf.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/spinlock.h>
15 #include <linux/err.h>
16 #include <linux/list.h>
17 #include <linux/slab.h>
18 #include <linux/of.h>
19 #include <linux/device.h>
20 #include <linux/init.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/sched.h>
23 #include <linux/clkdev.h>
24 
25 #include "clk.h"
26 
27 static DEFINE_SPINLOCK(enable_lock);
28 static DEFINE_MUTEX(prepare_lock);
29 
30 static struct task_struct *prepare_owner;
31 static struct task_struct *enable_owner;
32 
33 static int prepare_refcnt;
34 static int enable_refcnt;
35 
36 static HLIST_HEAD(clk_root_list);
37 static HLIST_HEAD(clk_orphan_list);
38 static LIST_HEAD(clk_notifier_list);
39 
40 static const struct hlist_head *all_lists[] = {
41 	&clk_root_list,
42 	&clk_orphan_list,
43 	NULL,
44 };
45 
46 /***    private data structures    ***/
47 
48 struct clk_parent_map {
49 	const struct clk_hw	*hw;
50 	struct clk_core		*core;
51 	const char		*fw_name;
52 	const char		*name;
53 	int			index;
54 };
55 
56 struct clk_core {
57 	const char		*name;
58 	const struct clk_ops	*ops;
59 	struct clk_hw		*hw;
60 	struct module		*owner;
61 	struct device		*dev;
62 	struct device_node	*of_node;
63 	struct clk_core		*parent;
64 	struct clk_parent_map	*parents;
65 	u8			num_parents;
66 	u8			new_parent_index;
67 	unsigned long		rate;
68 	unsigned long		req_rate;
69 	unsigned long		new_rate;
70 	struct clk_core		*new_parent;
71 	struct clk_core		*new_child;
72 	unsigned long		flags;
73 	bool			orphan;
74 	bool			rpm_enabled;
75 	unsigned int		enable_count;
76 	unsigned int		prepare_count;
77 	unsigned int		protect_count;
78 	unsigned long		min_rate;
79 	unsigned long		max_rate;
80 	unsigned long		accuracy;
81 	int			phase;
82 	struct clk_duty		duty;
83 	struct hlist_head	children;
84 	struct hlist_node	child_node;
85 	struct hlist_head	clks;
86 	unsigned int		notifier_count;
87 #ifdef CONFIG_DEBUG_FS
88 	struct dentry		*dentry;
89 	struct hlist_node	debug_node;
90 #endif
91 	struct kref		ref;
92 };
93 
94 #define CREATE_TRACE_POINTS
95 #include <trace/events/clk.h>
96 
97 struct clk {
98 	struct clk_core	*core;
99 	struct device *dev;
100 	const char *dev_id;
101 	const char *con_id;
102 	unsigned long min_rate;
103 	unsigned long max_rate;
104 	unsigned int exclusive_count;
105 	struct hlist_node clks_node;
106 };
107 
108 /***           runtime pm          ***/
clk_pm_runtime_get(struct clk_core * core)109 static int clk_pm_runtime_get(struct clk_core *core)
110 {
111 	if (!core->rpm_enabled)
112 		return 0;
113 
114 	return pm_runtime_resume_and_get(core->dev);
115 }
116 
clk_pm_runtime_put(struct clk_core * core)117 static void clk_pm_runtime_put(struct clk_core *core)
118 {
119 	if (!core->rpm_enabled)
120 		return;
121 
122 	pm_runtime_put_sync(core->dev);
123 }
124 
125 /***           locking             ***/
clk_prepare_lock(void)126 static void clk_prepare_lock(void)
127 {
128 	if (!mutex_trylock(&prepare_lock)) {
129 		if (prepare_owner == current) {
130 			prepare_refcnt++;
131 			return;
132 		}
133 		mutex_lock(&prepare_lock);
134 	}
135 	WARN_ON_ONCE(prepare_owner != NULL);
136 	WARN_ON_ONCE(prepare_refcnt != 0);
137 	prepare_owner = current;
138 	prepare_refcnt = 1;
139 }
140 
clk_prepare_unlock(void)141 static void clk_prepare_unlock(void)
142 {
143 	WARN_ON_ONCE(prepare_owner != current);
144 	WARN_ON_ONCE(prepare_refcnt == 0);
145 
146 	if (--prepare_refcnt)
147 		return;
148 	prepare_owner = NULL;
149 	mutex_unlock(&prepare_lock);
150 }
151 
clk_enable_lock(void)152 static unsigned long clk_enable_lock(void)
153 	__acquires(enable_lock)
154 {
155 	unsigned long flags;
156 
157 	/*
158 	 * On UP systems, spin_trylock_irqsave() always returns true, even if
159 	 * we already hold the lock. So, in that case, we rely only on
160 	 * reference counting.
161 	 */
162 	if (!IS_ENABLED(CONFIG_SMP) ||
163 	    !spin_trylock_irqsave(&enable_lock, flags)) {
164 		if (enable_owner == current) {
165 			enable_refcnt++;
166 			__acquire(enable_lock);
167 			if (!IS_ENABLED(CONFIG_SMP))
168 				local_save_flags(flags);
169 			return flags;
170 		}
171 		spin_lock_irqsave(&enable_lock, flags);
172 	}
173 	WARN_ON_ONCE(enable_owner != NULL);
174 	WARN_ON_ONCE(enable_refcnt != 0);
175 	enable_owner = current;
176 	enable_refcnt = 1;
177 	return flags;
178 }
179 
clk_enable_unlock(unsigned long flags)180 static void clk_enable_unlock(unsigned long flags)
181 	__releases(enable_lock)
182 {
183 	WARN_ON_ONCE(enable_owner != current);
184 	WARN_ON_ONCE(enable_refcnt == 0);
185 
186 	if (--enable_refcnt) {
187 		__release(enable_lock);
188 		return;
189 	}
190 	enable_owner = NULL;
191 	spin_unlock_irqrestore(&enable_lock, flags);
192 }
193 
clk_core_rate_is_protected(struct clk_core * core)194 static bool clk_core_rate_is_protected(struct clk_core *core)
195 {
196 	return core->protect_count;
197 }
198 
clk_core_is_prepared(struct clk_core * core)199 static bool clk_core_is_prepared(struct clk_core *core)
200 {
201 	bool ret = false;
202 
203 	/*
204 	 * .is_prepared is optional for clocks that can prepare
205 	 * fall back to software usage counter if it is missing
206 	 */
207 	if (!core->ops->is_prepared)
208 		return core->prepare_count;
209 
210 	if (!clk_pm_runtime_get(core)) {
211 		ret = core->ops->is_prepared(core->hw);
212 		clk_pm_runtime_put(core);
213 	}
214 
215 	return ret;
216 }
217 
clk_core_is_enabled(struct clk_core * core)218 static bool clk_core_is_enabled(struct clk_core *core)
219 {
220 	bool ret = false;
221 
222 	/*
223 	 * .is_enabled is only mandatory for clocks that gate
224 	 * fall back to software usage counter if .is_enabled is missing
225 	 */
226 	if (!core->ops->is_enabled)
227 		return core->enable_count;
228 
229 	/*
230 	 * Check if clock controller's device is runtime active before
231 	 * calling .is_enabled callback. If not, assume that clock is
232 	 * disabled, because we might be called from atomic context, from
233 	 * which pm_runtime_get() is not allowed.
234 	 * This function is called mainly from clk_disable_unused_subtree,
235 	 * which ensures proper runtime pm activation of controller before
236 	 * taking enable spinlock, but the below check is needed if one tries
237 	 * to call it from other places.
238 	 */
239 	if (core->rpm_enabled) {
240 		pm_runtime_get_noresume(core->dev);
241 		if (!pm_runtime_active(core->dev)) {
242 			ret = false;
243 			goto done;
244 		}
245 	}
246 
247 	/*
248 	 * This could be called with the enable lock held, or from atomic
249 	 * context. If the parent isn't enabled already, we can't do
250 	 * anything here. We can also assume this clock isn't enabled.
251 	 */
252 	if ((core->flags & CLK_OPS_PARENT_ENABLE) && core->parent)
253 		if (!clk_core_is_enabled(core->parent)) {
254 			ret = false;
255 			goto done;
256 		}
257 
258 	ret = core->ops->is_enabled(core->hw);
259 done:
260 	if (core->rpm_enabled)
261 		pm_runtime_put(core->dev);
262 
263 	return ret;
264 }
265 
266 /***    helper functions   ***/
267 
__clk_get_name(const struct clk * clk)268 const char *__clk_get_name(const struct clk *clk)
269 {
270 	return !clk ? NULL : clk->core->name;
271 }
272 EXPORT_SYMBOL_GPL(__clk_get_name);
273 
clk_hw_get_name(const struct clk_hw * hw)274 const char *clk_hw_get_name(const struct clk_hw *hw)
275 {
276 	return hw->core->name;
277 }
278 EXPORT_SYMBOL_GPL(clk_hw_get_name);
279 
__clk_get_hw(struct clk * clk)280 struct clk_hw *__clk_get_hw(struct clk *clk)
281 {
282 	return !clk ? NULL : clk->core->hw;
283 }
284 EXPORT_SYMBOL_GPL(__clk_get_hw);
285 
clk_hw_get_num_parents(const struct clk_hw * hw)286 unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
287 {
288 	return hw->core->num_parents;
289 }
290 EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
291 
clk_hw_get_parent(const struct clk_hw * hw)292 struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
293 {
294 	return hw->core->parent ? hw->core->parent->hw : NULL;
295 }
296 EXPORT_SYMBOL_GPL(clk_hw_get_parent);
297 
__clk_lookup_subtree(const char * name,struct clk_core * core)298 static struct clk_core *__clk_lookup_subtree(const char *name,
299 					     struct clk_core *core)
300 {
301 	struct clk_core *child;
302 	struct clk_core *ret;
303 
304 	if (!strcmp(core->name, name))
305 		return core;
306 
307 	hlist_for_each_entry(child, &core->children, child_node) {
308 		ret = __clk_lookup_subtree(name, child);
309 		if (ret)
310 			return ret;
311 	}
312 
313 	return NULL;
314 }
315 
clk_core_lookup(const char * name)316 static struct clk_core *clk_core_lookup(const char *name)
317 {
318 	struct clk_core *root_clk;
319 	struct clk_core *ret;
320 
321 	if (!name)
322 		return NULL;
323 
324 	/* search the 'proper' clk tree first */
325 	hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
326 		ret = __clk_lookup_subtree(name, root_clk);
327 		if (ret)
328 			return ret;
329 	}
330 
331 	/* if not found, then search the orphan tree */
332 	hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
333 		ret = __clk_lookup_subtree(name, root_clk);
334 		if (ret)
335 			return ret;
336 	}
337 
338 	return NULL;
339 }
340 
341 #ifdef CONFIG_OF
342 static int of_parse_clkspec(const struct device_node *np, int index,
343 			    const char *name, struct of_phandle_args *out_args);
344 static struct clk_hw *
345 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec);
346 #else
of_parse_clkspec(const struct device_node * np,int index,const char * name,struct of_phandle_args * out_args)347 static inline int of_parse_clkspec(const struct device_node *np, int index,
348 				   const char *name,
349 				   struct of_phandle_args *out_args)
350 {
351 	return -ENOENT;
352 }
353 static inline struct clk_hw *
of_clk_get_hw_from_clkspec(struct of_phandle_args * clkspec)354 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
355 {
356 	return ERR_PTR(-ENOENT);
357 }
358 #endif
359 
360 /**
361  * clk_core_get - Find the clk_core parent of a clk
362  * @core: clk to find parent of
363  * @p_index: parent index to search for
364  *
365  * This is the preferred method for clk providers to find the parent of a
366  * clk when that parent is external to the clk controller. The parent_names
367  * array is indexed and treated as a local name matching a string in the device
368  * node's 'clock-names' property or as the 'con_id' matching the device's
369  * dev_name() in a clk_lookup. This allows clk providers to use their own
370  * namespace instead of looking for a globally unique parent string.
371  *
372  * For example the following DT snippet would allow a clock registered by the
373  * clock-controller@c001 that has a clk_init_data::parent_data array
374  * with 'xtal' in the 'name' member to find the clock provided by the
375  * clock-controller@f00abcd without needing to get the globally unique name of
376  * the xtal clk.
377  *
378  *      parent: clock-controller@f00abcd {
379  *              reg = <0xf00abcd 0xabcd>;
380  *              #clock-cells = <0>;
381  *      };
382  *
383  *      clock-controller@c001 {
384  *              reg = <0xc001 0xf00d>;
385  *              clocks = <&parent>;
386  *              clock-names = "xtal";
387  *              #clock-cells = <1>;
388  *      };
389  *
390  * Returns: -ENOENT when the provider can't be found or the clk doesn't
391  * exist in the provider or the name can't be found in the DT node or
392  * in a clkdev lookup. NULL when the provider knows about the clk but it
393  * isn't provided on this system.
394  * A valid clk_core pointer when the clk can be found in the provider.
395  */
clk_core_get(struct clk_core * core,u8 p_index)396 static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
397 {
398 	const char *name = core->parents[p_index].fw_name;
399 	int index = core->parents[p_index].index;
400 	struct clk_hw *hw = ERR_PTR(-ENOENT);
401 	struct device *dev = core->dev;
402 	const char *dev_id = dev ? dev_name(dev) : NULL;
403 	struct device_node *np = core->of_node;
404 	struct of_phandle_args clkspec;
405 
406 	if (np && (name || index >= 0) &&
407 	    !of_parse_clkspec(np, index, name, &clkspec)) {
408 		hw = of_clk_get_hw_from_clkspec(&clkspec);
409 		of_node_put(clkspec.np);
410 	} else if (name) {
411 		/*
412 		 * If the DT search above couldn't find the provider fallback to
413 		 * looking up via clkdev based clk_lookups.
414 		 */
415 		hw = clk_find_hw(dev_id, name);
416 	}
417 
418 	if (IS_ERR(hw))
419 		return ERR_CAST(hw);
420 
421 	return hw->core;
422 }
423 
clk_core_fill_parent_index(struct clk_core * core,u8 index)424 static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
425 {
426 	struct clk_parent_map *entry = &core->parents[index];
427 	struct clk_core *parent;
428 
429 	if (entry->hw) {
430 		parent = entry->hw->core;
431 	} else {
432 		parent = clk_core_get(core, index);
433 		if (PTR_ERR(parent) == -ENOENT && entry->name)
434 			parent = clk_core_lookup(entry->name);
435 	}
436 
437 	/*
438 	 * We have a direct reference but it isn't registered yet?
439 	 * Orphan it and let clk_reparent() update the orphan status
440 	 * when the parent is registered.
441 	 */
442 	if (!parent)
443 		parent = ERR_PTR(-EPROBE_DEFER);
444 
445 	/* Only cache it if it's not an error */
446 	if (!IS_ERR(parent))
447 		entry->core = parent;
448 }
449 
clk_core_get_parent_by_index(struct clk_core * core,u8 index)450 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
451 							 u8 index)
452 {
453 	if (!core || index >= core->num_parents || !core->parents)
454 		return NULL;
455 
456 	if (!core->parents[index].core)
457 		clk_core_fill_parent_index(core, index);
458 
459 	return core->parents[index].core;
460 }
461 
462 struct clk_hw *
clk_hw_get_parent_by_index(const struct clk_hw * hw,unsigned int index)463 clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
464 {
465 	struct clk_core *parent;
466 
467 	parent = clk_core_get_parent_by_index(hw->core, index);
468 
469 	return !parent ? NULL : parent->hw;
470 }
471 EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
472 
__clk_get_enable_count(struct clk * clk)473 unsigned int __clk_get_enable_count(struct clk *clk)
474 {
475 	return !clk ? 0 : clk->core->enable_count;
476 }
477 
clk_core_get_rate_nolock(struct clk_core * core)478 static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
479 {
480 	if (!core)
481 		return 0;
482 
483 	if (!core->num_parents || core->parent)
484 		return core->rate;
485 
486 	/*
487 	 * Clk must have a parent because num_parents > 0 but the parent isn't
488 	 * known yet. Best to return 0 as the rate of this clk until we can
489 	 * properly recalc the rate based on the parent's rate.
490 	 */
491 	return 0;
492 }
493 
clk_hw_get_rate(const struct clk_hw * hw)494 unsigned long clk_hw_get_rate(const struct clk_hw *hw)
495 {
496 	return clk_core_get_rate_nolock(hw->core);
497 }
498 EXPORT_SYMBOL_GPL(clk_hw_get_rate);
499 
clk_core_get_accuracy_no_lock(struct clk_core * core)500 static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
501 {
502 	if (!core)
503 		return 0;
504 
505 	return core->accuracy;
506 }
507 
clk_hw_get_flags(const struct clk_hw * hw)508 unsigned long clk_hw_get_flags(const struct clk_hw *hw)
509 {
510 	return hw->core->flags;
511 }
512 EXPORT_SYMBOL_GPL(clk_hw_get_flags);
513 
clk_hw_is_prepared(const struct clk_hw * hw)514 bool clk_hw_is_prepared(const struct clk_hw *hw)
515 {
516 	return clk_core_is_prepared(hw->core);
517 }
518 EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
519 
clk_hw_rate_is_protected(const struct clk_hw * hw)520 bool clk_hw_rate_is_protected(const struct clk_hw *hw)
521 {
522 	return clk_core_rate_is_protected(hw->core);
523 }
524 EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
525 
clk_hw_is_enabled(const struct clk_hw * hw)526 bool clk_hw_is_enabled(const struct clk_hw *hw)
527 {
528 	return clk_core_is_enabled(hw->core);
529 }
530 EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
531 
__clk_is_enabled(struct clk * clk)532 bool __clk_is_enabled(struct clk *clk)
533 {
534 	if (!clk)
535 		return false;
536 
537 	return clk_core_is_enabled(clk->core);
538 }
539 EXPORT_SYMBOL_GPL(__clk_is_enabled);
540 
mux_is_better_rate(unsigned long rate,unsigned long now,unsigned long best,unsigned long flags)541 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
542 			   unsigned long best, unsigned long flags)
543 {
544 	if (flags & CLK_MUX_ROUND_CLOSEST)
545 		return abs(now - rate) < abs(best - rate);
546 
547 	return now <= rate && now > best;
548 }
549 
550 static void clk_core_init_rate_req(struct clk_core * const core,
551 				   struct clk_rate_request *req,
552 				   unsigned long rate);
553 
554 static int clk_core_round_rate_nolock(struct clk_core *core,
555 				      struct clk_rate_request *req);
556 
clk_core_has_parent(struct clk_core * core,const struct clk_core * parent)557 static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent)
558 {
559 	struct clk_core *tmp;
560 	unsigned int i;
561 
562 	/* Optimize for the case where the parent is already the parent. */
563 	if (core->parent == parent)
564 		return true;
565 
566 	for (i = 0; i < core->num_parents; i++) {
567 		tmp = clk_core_get_parent_by_index(core, i);
568 		if (!tmp)
569 			continue;
570 
571 		if (tmp == parent)
572 			return true;
573 	}
574 
575 	return false;
576 }
577 
578 static void
clk_core_forward_rate_req(struct clk_core * core,const struct clk_rate_request * old_req,struct clk_core * parent,struct clk_rate_request * req,unsigned long parent_rate)579 clk_core_forward_rate_req(struct clk_core *core,
580 			  const struct clk_rate_request *old_req,
581 			  struct clk_core *parent,
582 			  struct clk_rate_request *req,
583 			  unsigned long parent_rate)
584 {
585 	if (WARN_ON(!clk_core_has_parent(core, parent)))
586 		return;
587 
588 	clk_core_init_rate_req(parent, req, parent_rate);
589 
590 	if (req->min_rate < old_req->min_rate)
591 		req->min_rate = old_req->min_rate;
592 
593 	if (req->max_rate > old_req->max_rate)
594 		req->max_rate = old_req->max_rate;
595 }
596 
597 static int
clk_core_determine_rate_no_reparent(struct clk_hw * hw,struct clk_rate_request * req)598 clk_core_determine_rate_no_reparent(struct clk_hw *hw,
599 				    struct clk_rate_request *req)
600 {
601 	struct clk_core *core = hw->core;
602 	struct clk_core *parent = core->parent;
603 	unsigned long best;
604 	int ret;
605 
606 	if (core->flags & CLK_SET_RATE_PARENT) {
607 		struct clk_rate_request parent_req;
608 
609 		if (!parent) {
610 			req->rate = 0;
611 			return 0;
612 		}
613 
614 		clk_core_forward_rate_req(core, req, parent, &parent_req,
615 					  req->rate);
616 
617 		trace_clk_rate_request_start(&parent_req);
618 
619 		ret = clk_core_round_rate_nolock(parent, &parent_req);
620 		if (ret)
621 			return ret;
622 
623 		trace_clk_rate_request_done(&parent_req);
624 
625 		best = parent_req.rate;
626 	} else if (parent) {
627 		best = clk_core_get_rate_nolock(parent);
628 	} else {
629 		best = clk_core_get_rate_nolock(core);
630 	}
631 
632 	req->best_parent_rate = best;
633 	req->rate = best;
634 
635 	return 0;
636 }
637 
clk_mux_determine_rate_flags(struct clk_hw * hw,struct clk_rate_request * req,unsigned long flags)638 int clk_mux_determine_rate_flags(struct clk_hw *hw,
639 				 struct clk_rate_request *req,
640 				 unsigned long flags)
641 {
642 	struct clk_core *core = hw->core, *parent, *best_parent = NULL;
643 	int i, num_parents, ret;
644 	unsigned long best = 0;
645 
646 	/* if NO_REPARENT flag set, pass through to current parent */
647 	if (core->flags & CLK_SET_RATE_NO_REPARENT)
648 		return clk_core_determine_rate_no_reparent(hw, req);
649 
650 	/* find the parent that can provide the fastest rate <= rate */
651 	num_parents = core->num_parents;
652 	for (i = 0; i < num_parents; i++) {
653 		unsigned long parent_rate;
654 
655 		parent = clk_core_get_parent_by_index(core, i);
656 		if (!parent)
657 			continue;
658 
659 		if (core->flags & CLK_SET_RATE_PARENT) {
660 			struct clk_rate_request parent_req;
661 
662 			clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
663 
664 			trace_clk_rate_request_start(&parent_req);
665 
666 			ret = clk_core_round_rate_nolock(parent, &parent_req);
667 			if (ret)
668 				continue;
669 
670 			trace_clk_rate_request_done(&parent_req);
671 
672 			parent_rate = parent_req.rate;
673 		} else {
674 			parent_rate = clk_core_get_rate_nolock(parent);
675 		}
676 
677 		if (mux_is_better_rate(req->rate, parent_rate,
678 				       best, flags)) {
679 			best_parent = parent;
680 			best = parent_rate;
681 		}
682 	}
683 
684 	if (!best_parent)
685 		return -EINVAL;
686 
687 	req->best_parent_hw = best_parent->hw;
688 	req->best_parent_rate = best;
689 	req->rate = best;
690 
691 	return 0;
692 }
693 EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
694 
__clk_lookup(const char * name)695 struct clk *__clk_lookup(const char *name)
696 {
697 	struct clk_core *core = clk_core_lookup(name);
698 
699 	return !core ? NULL : core->hw->clk;
700 }
701 
clk_core_get_boundaries(struct clk_core * core,unsigned long * min_rate,unsigned long * max_rate)702 static void clk_core_get_boundaries(struct clk_core *core,
703 				    unsigned long *min_rate,
704 				    unsigned long *max_rate)
705 {
706 	struct clk *clk_user;
707 
708 	lockdep_assert_held(&prepare_lock);
709 
710 	*min_rate = core->min_rate;
711 	*max_rate = core->max_rate;
712 
713 	hlist_for_each_entry(clk_user, &core->clks, clks_node)
714 		*min_rate = max(*min_rate, clk_user->min_rate);
715 
716 	hlist_for_each_entry(clk_user, &core->clks, clks_node)
717 		*max_rate = min(*max_rate, clk_user->max_rate);
718 }
719 
720 /*
721  * clk_hw_get_rate_range() - returns the clock rate range for a hw clk
722  * @hw: the hw clk we want to get the range from
723  * @min_rate: pointer to the variable that will hold the minimum
724  * @max_rate: pointer to the variable that will hold the maximum
725  *
726  * Fills the @min_rate and @max_rate variables with the minimum and
727  * maximum that clock can reach.
728  */
clk_hw_get_rate_range(struct clk_hw * hw,unsigned long * min_rate,unsigned long * max_rate)729 void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate,
730 			   unsigned long *max_rate)
731 {
732 	clk_core_get_boundaries(hw->core, min_rate, max_rate);
733 }
734 EXPORT_SYMBOL_GPL(clk_hw_get_rate_range);
735 
clk_core_check_boundaries(struct clk_core * core,unsigned long min_rate,unsigned long max_rate)736 static bool clk_core_check_boundaries(struct clk_core *core,
737 				      unsigned long min_rate,
738 				      unsigned long max_rate)
739 {
740 	struct clk *user;
741 
742 	lockdep_assert_held(&prepare_lock);
743 
744 	if (min_rate > core->max_rate || max_rate < core->min_rate)
745 		return false;
746 
747 	hlist_for_each_entry(user, &core->clks, clks_node)
748 		if (min_rate > user->max_rate || max_rate < user->min_rate)
749 			return false;
750 
751 	return true;
752 }
753 
clk_hw_set_rate_range(struct clk_hw * hw,unsigned long min_rate,unsigned long max_rate)754 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
755 			   unsigned long max_rate)
756 {
757 	hw->core->min_rate = min_rate;
758 	hw->core->max_rate = max_rate;
759 }
760 EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
761 
762 /*
763  * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
764  * @hw: mux type clk to determine rate on
765  * @req: rate request, also used to return preferred parent and frequencies
766  *
767  * Helper for finding best parent to provide a given frequency. This can be used
768  * directly as a determine_rate callback (e.g. for a mux), or from a more
769  * complex clock that may combine a mux with other operations.
770  *
771  * Returns: 0 on success, -EERROR value on error
772  */
__clk_mux_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)773 int __clk_mux_determine_rate(struct clk_hw *hw,
774 			     struct clk_rate_request *req)
775 {
776 	return clk_mux_determine_rate_flags(hw, req, 0);
777 }
778 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
779 
__clk_mux_determine_rate_closest(struct clk_hw * hw,struct clk_rate_request * req)780 int __clk_mux_determine_rate_closest(struct clk_hw *hw,
781 				     struct clk_rate_request *req)
782 {
783 	return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
784 }
785 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
786 
787 /*
788  * clk_hw_determine_rate_no_reparent - clk_ops::determine_rate implementation for a clk that doesn't reparent
789  * @hw: mux type clk to determine rate on
790  * @req: rate request, also used to return preferred frequency
791  *
792  * Helper for finding best parent rate to provide a given frequency.
793  * This can be used directly as a determine_rate callback (e.g. for a
794  * mux), or from a more complex clock that may combine a mux with other
795  * operations.
796  *
797  * Returns: 0 on success, -EERROR value on error
798  */
clk_hw_determine_rate_no_reparent(struct clk_hw * hw,struct clk_rate_request * req)799 int clk_hw_determine_rate_no_reparent(struct clk_hw *hw,
800 				      struct clk_rate_request *req)
801 {
802 	return clk_core_determine_rate_no_reparent(hw, req);
803 }
804 EXPORT_SYMBOL_GPL(clk_hw_determine_rate_no_reparent);
805 
806 /***        clk api        ***/
807 
clk_core_rate_unprotect(struct clk_core * core)808 static void clk_core_rate_unprotect(struct clk_core *core)
809 {
810 	lockdep_assert_held(&prepare_lock);
811 
812 	if (!core)
813 		return;
814 
815 	if (WARN(core->protect_count == 0,
816 	    "%s already unprotected\n", core->name))
817 		return;
818 
819 	if (--core->protect_count > 0)
820 		return;
821 
822 	clk_core_rate_unprotect(core->parent);
823 }
824 
clk_core_rate_nuke_protect(struct clk_core * core)825 static int clk_core_rate_nuke_protect(struct clk_core *core)
826 {
827 	int ret;
828 
829 	lockdep_assert_held(&prepare_lock);
830 
831 	if (!core)
832 		return -EINVAL;
833 
834 	if (core->protect_count == 0)
835 		return 0;
836 
837 	ret = core->protect_count;
838 	core->protect_count = 1;
839 	clk_core_rate_unprotect(core);
840 
841 	return ret;
842 }
843 
844 /**
845  * clk_rate_exclusive_put - release exclusivity over clock rate control
846  * @clk: the clk over which the exclusivity is released
847  *
848  * clk_rate_exclusive_put() completes a critical section during which a clock
849  * consumer cannot tolerate any other consumer making any operation on the
850  * clock which could result in a rate change or rate glitch. Exclusive clocks
851  * cannot have their rate changed, either directly or indirectly due to changes
852  * further up the parent chain of clocks. As a result, clocks up parent chain
853  * also get under exclusive control of the calling consumer.
854  *
855  * If exlusivity is claimed more than once on clock, even by the same consumer,
856  * the rate effectively gets locked as exclusivity can't be preempted.
857  *
858  * Calls to clk_rate_exclusive_put() must be balanced with calls to
859  * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
860  * error status.
861  */
clk_rate_exclusive_put(struct clk * clk)862 void clk_rate_exclusive_put(struct clk *clk)
863 {
864 	if (!clk)
865 		return;
866 
867 	clk_prepare_lock();
868 
869 	/*
870 	 * if there is something wrong with this consumer protect count, stop
871 	 * here before messing with the provider
872 	 */
873 	if (WARN_ON(clk->exclusive_count <= 0))
874 		goto out;
875 
876 	clk_core_rate_unprotect(clk->core);
877 	clk->exclusive_count--;
878 out:
879 	clk_prepare_unlock();
880 }
881 EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
882 
clk_core_rate_protect(struct clk_core * core)883 static void clk_core_rate_protect(struct clk_core *core)
884 {
885 	lockdep_assert_held(&prepare_lock);
886 
887 	if (!core)
888 		return;
889 
890 	if (core->protect_count == 0)
891 		clk_core_rate_protect(core->parent);
892 
893 	core->protect_count++;
894 }
895 
clk_core_rate_restore_protect(struct clk_core * core,int count)896 static void clk_core_rate_restore_protect(struct clk_core *core, int count)
897 {
898 	lockdep_assert_held(&prepare_lock);
899 
900 	if (!core)
901 		return;
902 
903 	if (count == 0)
904 		return;
905 
906 	clk_core_rate_protect(core);
907 	core->protect_count = count;
908 }
909 
910 /**
911  * clk_rate_exclusive_get - get exclusivity over the clk rate control
912  * @clk: the clk over which the exclusity of rate control is requested
913  *
914  * clk_rate_exclusive_get() begins a critical section during which a clock
915  * consumer cannot tolerate any other consumer making any operation on the
916  * clock which could result in a rate change or rate glitch. Exclusive clocks
917  * cannot have their rate changed, either directly or indirectly due to changes
918  * further up the parent chain of clocks. As a result, clocks up parent chain
919  * also get under exclusive control of the calling consumer.
920  *
921  * If exlusivity is claimed more than once on clock, even by the same consumer,
922  * the rate effectively gets locked as exclusivity can't be preempted.
923  *
924  * Calls to clk_rate_exclusive_get() should be balanced with calls to
925  * clk_rate_exclusive_put(). Calls to this function may sleep.
926  * Returns 0 on success, -EERROR otherwise
927  */
clk_rate_exclusive_get(struct clk * clk)928 int clk_rate_exclusive_get(struct clk *clk)
929 {
930 	if (!clk)
931 		return 0;
932 
933 	clk_prepare_lock();
934 	clk_core_rate_protect(clk->core);
935 	clk->exclusive_count++;
936 	clk_prepare_unlock();
937 
938 	return 0;
939 }
940 EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
941 
clk_core_unprepare(struct clk_core * core)942 static void clk_core_unprepare(struct clk_core *core)
943 {
944 	lockdep_assert_held(&prepare_lock);
945 
946 	if (!core)
947 		return;
948 
949 	if (WARN(core->prepare_count == 0,
950 	    "%s already unprepared\n", core->name))
951 		return;
952 
953 	if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
954 	    "Unpreparing critical %s\n", core->name))
955 		return;
956 
957 	if (core->flags & CLK_SET_RATE_GATE)
958 		clk_core_rate_unprotect(core);
959 
960 	if (--core->prepare_count > 0)
961 		return;
962 
963 	WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
964 
965 	trace_clk_unprepare(core);
966 
967 	if (core->ops->unprepare)
968 		core->ops->unprepare(core->hw);
969 
970 	trace_clk_unprepare_complete(core);
971 	clk_core_unprepare(core->parent);
972 	clk_pm_runtime_put(core);
973 }
974 
clk_core_unprepare_lock(struct clk_core * core)975 static void clk_core_unprepare_lock(struct clk_core *core)
976 {
977 	clk_prepare_lock();
978 	clk_core_unprepare(core);
979 	clk_prepare_unlock();
980 }
981 
982 /**
983  * clk_unprepare - undo preparation of a clock source
984  * @clk: the clk being unprepared
985  *
986  * clk_unprepare may sleep, which differentiates it from clk_disable.  In a
987  * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
988  * if the operation may sleep.  One example is a clk which is accessed over
989  * I2c.  In the complex case a clk gate operation may require a fast and a slow
990  * part.  It is this reason that clk_unprepare and clk_disable are not mutually
991  * exclusive.  In fact clk_disable must be called before clk_unprepare.
992  */
clk_unprepare(struct clk * clk)993 void clk_unprepare(struct clk *clk)
994 {
995 	if (IS_ERR_OR_NULL(clk))
996 		return;
997 
998 	clk_core_unprepare_lock(clk->core);
999 }
1000 EXPORT_SYMBOL_GPL(clk_unprepare);
1001 
clk_core_prepare(struct clk_core * core)1002 static int clk_core_prepare(struct clk_core *core)
1003 {
1004 	int ret = 0;
1005 
1006 	lockdep_assert_held(&prepare_lock);
1007 
1008 	if (!core)
1009 		return 0;
1010 
1011 	if (core->prepare_count == 0) {
1012 		ret = clk_pm_runtime_get(core);
1013 		if (ret)
1014 			return ret;
1015 
1016 		ret = clk_core_prepare(core->parent);
1017 		if (ret)
1018 			goto runtime_put;
1019 
1020 		trace_clk_prepare(core);
1021 
1022 		if (core->ops->prepare)
1023 			ret = core->ops->prepare(core->hw);
1024 
1025 		trace_clk_prepare_complete(core);
1026 
1027 		if (ret)
1028 			goto unprepare;
1029 	}
1030 
1031 	core->prepare_count++;
1032 
1033 	/*
1034 	 * CLK_SET_RATE_GATE is a special case of clock protection
1035 	 * Instead of a consumer claiming exclusive rate control, it is
1036 	 * actually the provider which prevents any consumer from making any
1037 	 * operation which could result in a rate change or rate glitch while
1038 	 * the clock is prepared.
1039 	 */
1040 	if (core->flags & CLK_SET_RATE_GATE)
1041 		clk_core_rate_protect(core);
1042 
1043 	return 0;
1044 unprepare:
1045 	clk_core_unprepare(core->parent);
1046 runtime_put:
1047 	clk_pm_runtime_put(core);
1048 	return ret;
1049 }
1050 
clk_core_prepare_lock(struct clk_core * core)1051 static int clk_core_prepare_lock(struct clk_core *core)
1052 {
1053 	int ret;
1054 
1055 	clk_prepare_lock();
1056 	ret = clk_core_prepare(core);
1057 	clk_prepare_unlock();
1058 
1059 	return ret;
1060 }
1061 
1062 /**
1063  * clk_prepare - prepare a clock source
1064  * @clk: the clk being prepared
1065  *
1066  * clk_prepare may sleep, which differentiates it from clk_enable.  In a simple
1067  * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
1068  * operation may sleep.  One example is a clk which is accessed over I2c.  In
1069  * the complex case a clk ungate operation may require a fast and a slow part.
1070  * It is this reason that clk_prepare and clk_enable are not mutually
1071  * exclusive.  In fact clk_prepare must be called before clk_enable.
1072  * Returns 0 on success, -EERROR otherwise.
1073  */
clk_prepare(struct clk * clk)1074 int clk_prepare(struct clk *clk)
1075 {
1076 	if (!clk)
1077 		return 0;
1078 
1079 	return clk_core_prepare_lock(clk->core);
1080 }
1081 EXPORT_SYMBOL_GPL(clk_prepare);
1082 
clk_core_disable(struct clk_core * core)1083 static void clk_core_disable(struct clk_core *core)
1084 {
1085 	lockdep_assert_held(&enable_lock);
1086 
1087 	if (!core)
1088 		return;
1089 
1090 	if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
1091 		return;
1092 
1093 	if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
1094 	    "Disabling critical %s\n", core->name))
1095 		return;
1096 
1097 	if (--core->enable_count > 0)
1098 		return;
1099 
1100 	trace_clk_disable(core);
1101 
1102 	if (core->ops->disable)
1103 		core->ops->disable(core->hw);
1104 
1105 	trace_clk_disable_complete(core);
1106 
1107 	clk_core_disable(core->parent);
1108 }
1109 
clk_core_disable_lock(struct clk_core * core)1110 static void clk_core_disable_lock(struct clk_core *core)
1111 {
1112 	unsigned long flags;
1113 
1114 	flags = clk_enable_lock();
1115 	clk_core_disable(core);
1116 	clk_enable_unlock(flags);
1117 }
1118 
1119 /**
1120  * clk_disable - gate a clock
1121  * @clk: the clk being gated
1122  *
1123  * clk_disable must not sleep, which differentiates it from clk_unprepare.  In
1124  * a simple case, clk_disable can be used instead of clk_unprepare to gate a
1125  * clk if the operation is fast and will never sleep.  One example is a
1126  * SoC-internal clk which is controlled via simple register writes.  In the
1127  * complex case a clk gate operation may require a fast and a slow part.  It is
1128  * this reason that clk_unprepare and clk_disable are not mutually exclusive.
1129  * In fact clk_disable must be called before clk_unprepare.
1130  */
clk_disable(struct clk * clk)1131 void clk_disable(struct clk *clk)
1132 {
1133 	if (IS_ERR_OR_NULL(clk))
1134 		return;
1135 
1136 	clk_core_disable_lock(clk->core);
1137 }
1138 EXPORT_SYMBOL_GPL(clk_disable);
1139 
clk_core_enable(struct clk_core * core)1140 static int clk_core_enable(struct clk_core *core)
1141 {
1142 	int ret = 0;
1143 
1144 	lockdep_assert_held(&enable_lock);
1145 
1146 	if (!core)
1147 		return 0;
1148 
1149 	if (WARN(core->prepare_count == 0,
1150 	    "Enabling unprepared %s\n", core->name))
1151 		return -ESHUTDOWN;
1152 
1153 	if (core->enable_count == 0) {
1154 		ret = clk_core_enable(core->parent);
1155 
1156 		if (ret)
1157 			return ret;
1158 
1159 		trace_clk_enable(core);
1160 
1161 		if (core->ops->enable)
1162 			ret = core->ops->enable(core->hw);
1163 
1164 		trace_clk_enable_complete(core);
1165 
1166 		if (ret) {
1167 			clk_core_disable(core->parent);
1168 			return ret;
1169 		}
1170 	}
1171 
1172 	core->enable_count++;
1173 	return 0;
1174 }
1175 
clk_core_enable_lock(struct clk_core * core)1176 static int clk_core_enable_lock(struct clk_core *core)
1177 {
1178 	unsigned long flags;
1179 	int ret;
1180 
1181 	flags = clk_enable_lock();
1182 	ret = clk_core_enable(core);
1183 	clk_enable_unlock(flags);
1184 
1185 	return ret;
1186 }
1187 
1188 /**
1189  * clk_gate_restore_context - restore context for poweroff
1190  * @hw: the clk_hw pointer of clock whose state is to be restored
1191  *
1192  * The clock gate restore context function enables or disables
1193  * the gate clocks based on the enable_count. This is done in cases
1194  * where the clock context is lost and based on the enable_count
1195  * the clock either needs to be enabled/disabled. This
1196  * helps restore the state of gate clocks.
1197  */
clk_gate_restore_context(struct clk_hw * hw)1198 void clk_gate_restore_context(struct clk_hw *hw)
1199 {
1200 	struct clk_core *core = hw->core;
1201 
1202 	if (core->enable_count)
1203 		core->ops->enable(hw);
1204 	else
1205 		core->ops->disable(hw);
1206 }
1207 EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1208 
clk_core_save_context(struct clk_core * core)1209 static int clk_core_save_context(struct clk_core *core)
1210 {
1211 	struct clk_core *child;
1212 	int ret = 0;
1213 
1214 	hlist_for_each_entry(child, &core->children, child_node) {
1215 		ret = clk_core_save_context(child);
1216 		if (ret < 0)
1217 			return ret;
1218 	}
1219 
1220 	if (core->ops && core->ops->save_context)
1221 		ret = core->ops->save_context(core->hw);
1222 
1223 	return ret;
1224 }
1225 
clk_core_restore_context(struct clk_core * core)1226 static void clk_core_restore_context(struct clk_core *core)
1227 {
1228 	struct clk_core *child;
1229 
1230 	if (core->ops && core->ops->restore_context)
1231 		core->ops->restore_context(core->hw);
1232 
1233 	hlist_for_each_entry(child, &core->children, child_node)
1234 		clk_core_restore_context(child);
1235 }
1236 
1237 /**
1238  * clk_save_context - save clock context for poweroff
1239  *
1240  * Saves the context of the clock register for powerstates in which the
1241  * contents of the registers will be lost. Occurs deep within the suspend
1242  * code.  Returns 0 on success.
1243  */
clk_save_context(void)1244 int clk_save_context(void)
1245 {
1246 	struct clk_core *clk;
1247 	int ret;
1248 
1249 	hlist_for_each_entry(clk, &clk_root_list, child_node) {
1250 		ret = clk_core_save_context(clk);
1251 		if (ret < 0)
1252 			return ret;
1253 	}
1254 
1255 	hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1256 		ret = clk_core_save_context(clk);
1257 		if (ret < 0)
1258 			return ret;
1259 	}
1260 
1261 	return 0;
1262 }
1263 EXPORT_SYMBOL_GPL(clk_save_context);
1264 
1265 /**
1266  * clk_restore_context - restore clock context after poweroff
1267  *
1268  * Restore the saved clock context upon resume.
1269  *
1270  */
clk_restore_context(void)1271 void clk_restore_context(void)
1272 {
1273 	struct clk_core *core;
1274 
1275 	hlist_for_each_entry(core, &clk_root_list, child_node)
1276 		clk_core_restore_context(core);
1277 
1278 	hlist_for_each_entry(core, &clk_orphan_list, child_node)
1279 		clk_core_restore_context(core);
1280 }
1281 EXPORT_SYMBOL_GPL(clk_restore_context);
1282 
1283 /**
1284  * clk_enable - ungate a clock
1285  * @clk: the clk being ungated
1286  *
1287  * clk_enable must not sleep, which differentiates it from clk_prepare.  In a
1288  * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1289  * if the operation will never sleep.  One example is a SoC-internal clk which
1290  * is controlled via simple register writes.  In the complex case a clk ungate
1291  * operation may require a fast and a slow part.  It is this reason that
1292  * clk_enable and clk_prepare are not mutually exclusive.  In fact clk_prepare
1293  * must be called before clk_enable.  Returns 0 on success, -EERROR
1294  * otherwise.
1295  */
clk_enable(struct clk * clk)1296 int clk_enable(struct clk *clk)
1297 {
1298 	if (!clk)
1299 		return 0;
1300 
1301 	return clk_core_enable_lock(clk->core);
1302 }
1303 EXPORT_SYMBOL_GPL(clk_enable);
1304 
1305 /**
1306  * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
1307  * @clk: clock source
1308  *
1309  * Returns true if clk_prepare() implicitly enables the clock, effectively
1310  * making clk_enable()/clk_disable() no-ops, false otherwise.
1311  *
1312  * This is of interest mainly to power management code where actually
1313  * disabling the clock also requires unpreparing it to have any material
1314  * effect.
1315  *
1316  * Regardless of the value returned here, the caller must always invoke
1317  * clk_enable() or clk_prepare_enable()  and counterparts for usage counts
1318  * to be right.
1319  */
clk_is_enabled_when_prepared(struct clk * clk)1320 bool clk_is_enabled_when_prepared(struct clk *clk)
1321 {
1322 	return clk && !(clk->core->ops->enable && clk->core->ops->disable);
1323 }
1324 EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);
1325 
clk_core_prepare_enable(struct clk_core * core)1326 static int clk_core_prepare_enable(struct clk_core *core)
1327 {
1328 	int ret;
1329 
1330 	ret = clk_core_prepare_lock(core);
1331 	if (ret)
1332 		return ret;
1333 
1334 	ret = clk_core_enable_lock(core);
1335 	if (ret)
1336 		clk_core_unprepare_lock(core);
1337 
1338 	return ret;
1339 }
1340 
clk_core_disable_unprepare(struct clk_core * core)1341 static void clk_core_disable_unprepare(struct clk_core *core)
1342 {
1343 	clk_core_disable_lock(core);
1344 	clk_core_unprepare_lock(core);
1345 }
1346 
clk_unprepare_unused_subtree(struct clk_core * core)1347 static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1348 {
1349 	struct clk_core *child;
1350 
1351 	lockdep_assert_held(&prepare_lock);
1352 
1353 	hlist_for_each_entry(child, &core->children, child_node)
1354 		clk_unprepare_unused_subtree(child);
1355 
1356 	if (core->prepare_count)
1357 		return;
1358 
1359 	if (core->flags & CLK_IGNORE_UNUSED)
1360 		return;
1361 
1362 	if (clk_pm_runtime_get(core))
1363 		return;
1364 
1365 	if (clk_core_is_prepared(core)) {
1366 		trace_clk_unprepare(core);
1367 		if (core->ops->unprepare_unused)
1368 			core->ops->unprepare_unused(core->hw);
1369 		else if (core->ops->unprepare)
1370 			core->ops->unprepare(core->hw);
1371 		trace_clk_unprepare_complete(core);
1372 	}
1373 
1374 	clk_pm_runtime_put(core);
1375 }
1376 
clk_disable_unused_subtree(struct clk_core * core)1377 static void __init clk_disable_unused_subtree(struct clk_core *core)
1378 {
1379 	struct clk_core *child;
1380 	unsigned long flags;
1381 
1382 	lockdep_assert_held(&prepare_lock);
1383 
1384 	hlist_for_each_entry(child, &core->children, child_node)
1385 		clk_disable_unused_subtree(child);
1386 
1387 	if (core->flags & CLK_OPS_PARENT_ENABLE)
1388 		clk_core_prepare_enable(core->parent);
1389 
1390 	if (clk_pm_runtime_get(core))
1391 		goto unprepare_out;
1392 
1393 	flags = clk_enable_lock();
1394 
1395 	if (core->enable_count)
1396 		goto unlock_out;
1397 
1398 	if (core->flags & CLK_IGNORE_UNUSED)
1399 		goto unlock_out;
1400 
1401 	/*
1402 	 * some gate clocks have special needs during the disable-unused
1403 	 * sequence.  call .disable_unused if available, otherwise fall
1404 	 * back to .disable
1405 	 */
1406 	if (clk_core_is_enabled(core)) {
1407 		trace_clk_disable(core);
1408 		if (core->ops->disable_unused)
1409 			core->ops->disable_unused(core->hw);
1410 		else if (core->ops->disable)
1411 			core->ops->disable(core->hw);
1412 		trace_clk_disable_complete(core);
1413 	}
1414 
1415 unlock_out:
1416 	clk_enable_unlock(flags);
1417 	clk_pm_runtime_put(core);
1418 unprepare_out:
1419 	if (core->flags & CLK_OPS_PARENT_ENABLE)
1420 		clk_core_disable_unprepare(core->parent);
1421 }
1422 
1423 static bool clk_ignore_unused __initdata;
clk_ignore_unused_setup(char * __unused)1424 static int __init clk_ignore_unused_setup(char *__unused)
1425 {
1426 	clk_ignore_unused = true;
1427 	return 1;
1428 }
1429 __setup("clk_ignore_unused", clk_ignore_unused_setup);
1430 
clk_disable_unused(void)1431 static int __init clk_disable_unused(void)
1432 {
1433 	struct clk_core *core;
1434 
1435 	if (clk_ignore_unused) {
1436 		pr_warn("clk: Not disabling unused clocks\n");
1437 		return 0;
1438 	}
1439 
1440 	pr_info("clk: Disabling unused clocks\n");
1441 
1442 	clk_prepare_lock();
1443 
1444 	hlist_for_each_entry(core, &clk_root_list, child_node)
1445 		clk_disable_unused_subtree(core);
1446 
1447 	hlist_for_each_entry(core, &clk_orphan_list, child_node)
1448 		clk_disable_unused_subtree(core);
1449 
1450 	hlist_for_each_entry(core, &clk_root_list, child_node)
1451 		clk_unprepare_unused_subtree(core);
1452 
1453 	hlist_for_each_entry(core, &clk_orphan_list, child_node)
1454 		clk_unprepare_unused_subtree(core);
1455 
1456 	clk_prepare_unlock();
1457 
1458 	return 0;
1459 }
1460 late_initcall_sync(clk_disable_unused);
1461 
clk_core_determine_round_nolock(struct clk_core * core,struct clk_rate_request * req)1462 static int clk_core_determine_round_nolock(struct clk_core *core,
1463 					   struct clk_rate_request *req)
1464 {
1465 	long rate;
1466 
1467 	lockdep_assert_held(&prepare_lock);
1468 
1469 	if (!core)
1470 		return 0;
1471 
1472 	/*
1473 	 * Some clock providers hand-craft their clk_rate_requests and
1474 	 * might not fill min_rate and max_rate.
1475 	 *
1476 	 * If it's the case, clamping the rate is equivalent to setting
1477 	 * the rate to 0 which is bad. Skip the clamping but complain so
1478 	 * that it gets fixed, hopefully.
1479 	 */
1480 	if (!req->min_rate && !req->max_rate)
1481 		pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n",
1482 			__func__, core->name);
1483 	else
1484 		req->rate = clamp(req->rate, req->min_rate, req->max_rate);
1485 
1486 	/*
1487 	 * At this point, core protection will be disabled
1488 	 * - if the provider is not protected at all
1489 	 * - if the calling consumer is the only one which has exclusivity
1490 	 *   over the provider
1491 	 */
1492 	if (clk_core_rate_is_protected(core)) {
1493 		req->rate = core->rate;
1494 	} else if (core->ops->determine_rate) {
1495 		return core->ops->determine_rate(core->hw, req);
1496 	} else if (core->ops->round_rate) {
1497 		rate = core->ops->round_rate(core->hw, req->rate,
1498 					     &req->best_parent_rate);
1499 		if (rate < 0)
1500 			return rate;
1501 
1502 		req->rate = rate;
1503 	} else {
1504 		return -EINVAL;
1505 	}
1506 
1507 	return 0;
1508 }
1509 
clk_core_init_rate_req(struct clk_core * const core,struct clk_rate_request * req,unsigned long rate)1510 static void clk_core_init_rate_req(struct clk_core * const core,
1511 				   struct clk_rate_request *req,
1512 				   unsigned long rate)
1513 {
1514 	struct clk_core *parent;
1515 
1516 	if (WARN_ON(!req))
1517 		return;
1518 
1519 	memset(req, 0, sizeof(*req));
1520 	req->max_rate = ULONG_MAX;
1521 
1522 	if (!core)
1523 		return;
1524 
1525 	req->core = core;
1526 	req->rate = rate;
1527 	clk_core_get_boundaries(core, &req->min_rate, &req->max_rate);
1528 
1529 	parent = core->parent;
1530 	if (parent) {
1531 		req->best_parent_hw = parent->hw;
1532 		req->best_parent_rate = parent->rate;
1533 	} else {
1534 		req->best_parent_hw = NULL;
1535 		req->best_parent_rate = 0;
1536 	}
1537 }
1538 
1539 /**
1540  * clk_hw_init_rate_request - Initializes a clk_rate_request
1541  * @hw: the clk for which we want to submit a rate request
1542  * @req: the clk_rate_request structure we want to initialise
1543  * @rate: the rate which is to be requested
1544  *
1545  * Initializes a clk_rate_request structure to submit to
1546  * __clk_determine_rate() or similar functions.
1547  */
clk_hw_init_rate_request(const struct clk_hw * hw,struct clk_rate_request * req,unsigned long rate)1548 void clk_hw_init_rate_request(const struct clk_hw *hw,
1549 			      struct clk_rate_request *req,
1550 			      unsigned long rate)
1551 {
1552 	if (WARN_ON(!hw || !req))
1553 		return;
1554 
1555 	clk_core_init_rate_req(hw->core, req, rate);
1556 }
1557 EXPORT_SYMBOL_GPL(clk_hw_init_rate_request);
1558 
1559 /**
1560  * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent
1561  * @hw: the original clock that got the rate request
1562  * @old_req: the original clk_rate_request structure we want to forward
1563  * @parent: the clk we want to forward @old_req to
1564  * @req: the clk_rate_request structure we want to initialise
1565  * @parent_rate: The rate which is to be requested to @parent
1566  *
1567  * Initializes a clk_rate_request structure to submit to a clock parent
1568  * in __clk_determine_rate() or similar functions.
1569  */
clk_hw_forward_rate_request(const struct clk_hw * hw,const struct clk_rate_request * old_req,const struct clk_hw * parent,struct clk_rate_request * req,unsigned long parent_rate)1570 void clk_hw_forward_rate_request(const struct clk_hw *hw,
1571 				 const struct clk_rate_request *old_req,
1572 				 const struct clk_hw *parent,
1573 				 struct clk_rate_request *req,
1574 				 unsigned long parent_rate)
1575 {
1576 	if (WARN_ON(!hw || !old_req || !parent || !req))
1577 		return;
1578 
1579 	clk_core_forward_rate_req(hw->core, old_req,
1580 				  parent->core, req,
1581 				  parent_rate);
1582 }
1583 EXPORT_SYMBOL_GPL(clk_hw_forward_rate_request);
1584 
clk_core_can_round(struct clk_core * const core)1585 static bool clk_core_can_round(struct clk_core * const core)
1586 {
1587 	return core->ops->determine_rate || core->ops->round_rate;
1588 }
1589 
clk_core_round_rate_nolock(struct clk_core * core,struct clk_rate_request * req)1590 static int clk_core_round_rate_nolock(struct clk_core *core,
1591 				      struct clk_rate_request *req)
1592 {
1593 	int ret;
1594 
1595 	lockdep_assert_held(&prepare_lock);
1596 
1597 	if (!core) {
1598 		req->rate = 0;
1599 		return 0;
1600 	}
1601 
1602 	if (clk_core_can_round(core))
1603 		return clk_core_determine_round_nolock(core, req);
1604 
1605 	if (core->flags & CLK_SET_RATE_PARENT) {
1606 		struct clk_rate_request parent_req;
1607 
1608 		clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate);
1609 
1610 		trace_clk_rate_request_start(&parent_req);
1611 
1612 		ret = clk_core_round_rate_nolock(core->parent, &parent_req);
1613 		if (ret)
1614 			return ret;
1615 
1616 		trace_clk_rate_request_done(&parent_req);
1617 
1618 		req->best_parent_rate = parent_req.rate;
1619 		req->rate = parent_req.rate;
1620 
1621 		return 0;
1622 	}
1623 
1624 	req->rate = core->rate;
1625 	return 0;
1626 }
1627 
1628 /**
1629  * __clk_determine_rate - get the closest rate actually supported by a clock
1630  * @hw: determine the rate of this clock
1631  * @req: target rate request
1632  *
1633  * Useful for clk_ops such as .set_rate and .determine_rate.
1634  */
__clk_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)1635 int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1636 {
1637 	if (!hw) {
1638 		req->rate = 0;
1639 		return 0;
1640 	}
1641 
1642 	return clk_core_round_rate_nolock(hw->core, req);
1643 }
1644 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1645 
1646 /**
1647  * clk_hw_round_rate() - round the given rate for a hw clk
1648  * @hw: the hw clk for which we are rounding a rate
1649  * @rate: the rate which is to be rounded
1650  *
1651  * Takes in a rate as input and rounds it to a rate that the clk can actually
1652  * use.
1653  *
1654  * Context: prepare_lock must be held.
1655  *          For clk providers to call from within clk_ops such as .round_rate,
1656  *          .determine_rate.
1657  *
1658  * Return: returns rounded rate of hw clk if clk supports round_rate operation
1659  *         else returns the parent rate.
1660  */
clk_hw_round_rate(struct clk_hw * hw,unsigned long rate)1661 unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1662 {
1663 	int ret;
1664 	struct clk_rate_request req;
1665 
1666 	clk_core_init_rate_req(hw->core, &req, rate);
1667 
1668 	trace_clk_rate_request_start(&req);
1669 
1670 	ret = clk_core_round_rate_nolock(hw->core, &req);
1671 	if (ret)
1672 		return 0;
1673 
1674 	trace_clk_rate_request_done(&req);
1675 
1676 	return req.rate;
1677 }
1678 EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1679 
1680 /**
1681  * clk_round_rate - round the given rate for a clk
1682  * @clk: the clk for which we are rounding a rate
1683  * @rate: the rate which is to be rounded
1684  *
1685  * Takes in a rate as input and rounds it to a rate that the clk can actually
1686  * use which is then returned.  If clk doesn't support round_rate operation
1687  * then the parent rate is returned.
1688  */
clk_round_rate(struct clk * clk,unsigned long rate)1689 long clk_round_rate(struct clk *clk, unsigned long rate)
1690 {
1691 	struct clk_rate_request req;
1692 	int ret;
1693 
1694 	if (!clk)
1695 		return 0;
1696 
1697 	clk_prepare_lock();
1698 
1699 	if (clk->exclusive_count)
1700 		clk_core_rate_unprotect(clk->core);
1701 
1702 	clk_core_init_rate_req(clk->core, &req, rate);
1703 
1704 	trace_clk_rate_request_start(&req);
1705 
1706 	ret = clk_core_round_rate_nolock(clk->core, &req);
1707 
1708 	trace_clk_rate_request_done(&req);
1709 
1710 	if (clk->exclusive_count)
1711 		clk_core_rate_protect(clk->core);
1712 
1713 	clk_prepare_unlock();
1714 
1715 	if (ret)
1716 		return ret;
1717 
1718 	return req.rate;
1719 }
1720 EXPORT_SYMBOL_GPL(clk_round_rate);
1721 
1722 /**
1723  * __clk_notify - call clk notifier chain
1724  * @core: clk that is changing rate
1725  * @msg: clk notifier type (see include/linux/clk.h)
1726  * @old_rate: old clk rate
1727  * @new_rate: new clk rate
1728  *
1729  * Triggers a notifier call chain on the clk rate-change notification
1730  * for 'clk'.  Passes a pointer to the struct clk and the previous
1731  * and current rates to the notifier callback.  Intended to be called by
1732  * internal clock code only.  Returns NOTIFY_DONE from the last driver
1733  * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1734  * a driver returns that.
1735  */
__clk_notify(struct clk_core * core,unsigned long msg,unsigned long old_rate,unsigned long new_rate)1736 static int __clk_notify(struct clk_core *core, unsigned long msg,
1737 		unsigned long old_rate, unsigned long new_rate)
1738 {
1739 	struct clk_notifier *cn;
1740 	struct clk_notifier_data cnd;
1741 	int ret = NOTIFY_DONE;
1742 
1743 	cnd.old_rate = old_rate;
1744 	cnd.new_rate = new_rate;
1745 
1746 	list_for_each_entry(cn, &clk_notifier_list, node) {
1747 		if (cn->clk->core == core) {
1748 			cnd.clk = cn->clk;
1749 			ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1750 					&cnd);
1751 			if (ret & NOTIFY_STOP_MASK)
1752 				return ret;
1753 		}
1754 	}
1755 
1756 	return ret;
1757 }
1758 
1759 /**
1760  * __clk_recalc_accuracies
1761  * @core: first clk in the subtree
1762  *
1763  * Walks the subtree of clks starting with clk and recalculates accuracies as
1764  * it goes.  Note that if a clk does not implement the .recalc_accuracy
1765  * callback then it is assumed that the clock will take on the accuracy of its
1766  * parent.
1767  */
__clk_recalc_accuracies(struct clk_core * core)1768 static void __clk_recalc_accuracies(struct clk_core *core)
1769 {
1770 	unsigned long parent_accuracy = 0;
1771 	struct clk_core *child;
1772 
1773 	lockdep_assert_held(&prepare_lock);
1774 
1775 	if (core->parent)
1776 		parent_accuracy = core->parent->accuracy;
1777 
1778 	if (core->ops->recalc_accuracy)
1779 		core->accuracy = core->ops->recalc_accuracy(core->hw,
1780 							  parent_accuracy);
1781 	else
1782 		core->accuracy = parent_accuracy;
1783 
1784 	hlist_for_each_entry(child, &core->children, child_node)
1785 		__clk_recalc_accuracies(child);
1786 }
1787 
clk_core_get_accuracy_recalc(struct clk_core * core)1788 static long clk_core_get_accuracy_recalc(struct clk_core *core)
1789 {
1790 	if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1791 		__clk_recalc_accuracies(core);
1792 
1793 	return clk_core_get_accuracy_no_lock(core);
1794 }
1795 
1796 /**
1797  * clk_get_accuracy - return the accuracy of clk
1798  * @clk: the clk whose accuracy is being returned
1799  *
1800  * Simply returns the cached accuracy of the clk, unless
1801  * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1802  * issued.
1803  * If clk is NULL then returns 0.
1804  */
clk_get_accuracy(struct clk * clk)1805 long clk_get_accuracy(struct clk *clk)
1806 {
1807 	long accuracy;
1808 
1809 	if (!clk)
1810 		return 0;
1811 
1812 	clk_prepare_lock();
1813 	accuracy = clk_core_get_accuracy_recalc(clk->core);
1814 	clk_prepare_unlock();
1815 
1816 	return accuracy;
1817 }
1818 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1819 
clk_recalc(struct clk_core * core,unsigned long parent_rate)1820 static unsigned long clk_recalc(struct clk_core *core,
1821 				unsigned long parent_rate)
1822 {
1823 	unsigned long rate = parent_rate;
1824 
1825 	if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1826 		rate = core->ops->recalc_rate(core->hw, parent_rate);
1827 		clk_pm_runtime_put(core);
1828 	}
1829 	return rate;
1830 }
1831 
1832 /**
1833  * __clk_recalc_rates
1834  * @core: first clk in the subtree
1835  * @update_req: Whether req_rate should be updated with the new rate
1836  * @msg: notification type (see include/linux/clk.h)
1837  *
1838  * Walks the subtree of clks starting with clk and recalculates rates as it
1839  * goes.  Note that if a clk does not implement the .recalc_rate callback then
1840  * it is assumed that the clock will take on the rate of its parent.
1841  *
1842  * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1843  * if necessary.
1844  */
__clk_recalc_rates(struct clk_core * core,bool update_req,unsigned long msg)1845 static void __clk_recalc_rates(struct clk_core *core, bool update_req,
1846 			       unsigned long msg)
1847 {
1848 	unsigned long old_rate;
1849 	unsigned long parent_rate = 0;
1850 	struct clk_core *child;
1851 
1852 	lockdep_assert_held(&prepare_lock);
1853 
1854 	old_rate = core->rate;
1855 
1856 	if (core->parent)
1857 		parent_rate = core->parent->rate;
1858 
1859 	core->rate = clk_recalc(core, parent_rate);
1860 	if (update_req)
1861 		core->req_rate = core->rate;
1862 
1863 	/*
1864 	 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1865 	 * & ABORT_RATE_CHANGE notifiers
1866 	 */
1867 	if (core->notifier_count && msg)
1868 		__clk_notify(core, msg, old_rate, core->rate);
1869 
1870 	hlist_for_each_entry(child, &core->children, child_node)
1871 		__clk_recalc_rates(child, update_req, msg);
1872 }
1873 
clk_core_get_rate_recalc(struct clk_core * core)1874 static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1875 {
1876 	if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1877 		__clk_recalc_rates(core, false, 0);
1878 
1879 	return clk_core_get_rate_nolock(core);
1880 }
1881 
1882 /**
1883  * clk_get_rate - return the rate of clk
1884  * @clk: the clk whose rate is being returned
1885  *
1886  * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1887  * is set, which means a recalc_rate will be issued. Can be called regardless of
1888  * the clock enabledness. If clk is NULL, or if an error occurred, then returns
1889  * 0.
1890  */
clk_get_rate(struct clk * clk)1891 unsigned long clk_get_rate(struct clk *clk)
1892 {
1893 	unsigned long rate;
1894 
1895 	if (!clk)
1896 		return 0;
1897 
1898 	clk_prepare_lock();
1899 	rate = clk_core_get_rate_recalc(clk->core);
1900 	clk_prepare_unlock();
1901 
1902 	return rate;
1903 }
1904 EXPORT_SYMBOL_GPL(clk_get_rate);
1905 
clk_fetch_parent_index(struct clk_core * core,struct clk_core * parent)1906 static int clk_fetch_parent_index(struct clk_core *core,
1907 				  struct clk_core *parent)
1908 {
1909 	int i;
1910 
1911 	if (!parent)
1912 		return -EINVAL;
1913 
1914 	for (i = 0; i < core->num_parents; i++) {
1915 		/* Found it first try! */
1916 		if (core->parents[i].core == parent)
1917 			return i;
1918 
1919 		/* Something else is here, so keep looking */
1920 		if (core->parents[i].core)
1921 			continue;
1922 
1923 		/* Maybe core hasn't been cached but the hw is all we know? */
1924 		if (core->parents[i].hw) {
1925 			if (core->parents[i].hw == parent->hw)
1926 				break;
1927 
1928 			/* Didn't match, but we're expecting a clk_hw */
1929 			continue;
1930 		}
1931 
1932 		/* Maybe it hasn't been cached (clk_set_parent() path) */
1933 		if (parent == clk_core_get(core, i))
1934 			break;
1935 
1936 		/* Fallback to comparing globally unique names */
1937 		if (core->parents[i].name &&
1938 		    !strcmp(parent->name, core->parents[i].name))
1939 			break;
1940 	}
1941 
1942 	if (i == core->num_parents)
1943 		return -EINVAL;
1944 
1945 	core->parents[i].core = parent;
1946 	return i;
1947 }
1948 
1949 /**
1950  * clk_hw_get_parent_index - return the index of the parent clock
1951  * @hw: clk_hw associated with the clk being consumed
1952  *
1953  * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1954  * clock does not have a current parent.
1955  */
clk_hw_get_parent_index(struct clk_hw * hw)1956 int clk_hw_get_parent_index(struct clk_hw *hw)
1957 {
1958 	struct clk_hw *parent = clk_hw_get_parent(hw);
1959 
1960 	if (WARN_ON(parent == NULL))
1961 		return -EINVAL;
1962 
1963 	return clk_fetch_parent_index(hw->core, parent->core);
1964 }
1965 EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
1966 
1967 /*
1968  * Update the orphan status of @core and all its children.
1969  */
clk_core_update_orphan_status(struct clk_core * core,bool is_orphan)1970 static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1971 {
1972 	struct clk_core *child;
1973 
1974 	core->orphan = is_orphan;
1975 
1976 	hlist_for_each_entry(child, &core->children, child_node)
1977 		clk_core_update_orphan_status(child, is_orphan);
1978 }
1979 
clk_reparent(struct clk_core * core,struct clk_core * new_parent)1980 static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1981 {
1982 	bool was_orphan = core->orphan;
1983 
1984 	hlist_del(&core->child_node);
1985 
1986 	if (new_parent) {
1987 		bool becomes_orphan = new_parent->orphan;
1988 
1989 		/* avoid duplicate POST_RATE_CHANGE notifications */
1990 		if (new_parent->new_child == core)
1991 			new_parent->new_child = NULL;
1992 
1993 		hlist_add_head(&core->child_node, &new_parent->children);
1994 
1995 		if (was_orphan != becomes_orphan)
1996 			clk_core_update_orphan_status(core, becomes_orphan);
1997 	} else {
1998 		hlist_add_head(&core->child_node, &clk_orphan_list);
1999 		if (!was_orphan)
2000 			clk_core_update_orphan_status(core, true);
2001 	}
2002 
2003 	core->parent = new_parent;
2004 }
2005 
__clk_set_parent_before(struct clk_core * core,struct clk_core * parent)2006 static struct clk_core *__clk_set_parent_before(struct clk_core *core,
2007 					   struct clk_core *parent)
2008 {
2009 	unsigned long flags;
2010 	struct clk_core *old_parent = core->parent;
2011 
2012 	/*
2013 	 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
2014 	 *
2015 	 * 2. Migrate prepare state between parents and prevent race with
2016 	 * clk_enable().
2017 	 *
2018 	 * If the clock is not prepared, then a race with
2019 	 * clk_enable/disable() is impossible since we already have the
2020 	 * prepare lock (future calls to clk_enable() need to be preceded by
2021 	 * a clk_prepare()).
2022 	 *
2023 	 * If the clock is prepared, migrate the prepared state to the new
2024 	 * parent and also protect against a race with clk_enable() by
2025 	 * forcing the clock and the new parent on.  This ensures that all
2026 	 * future calls to clk_enable() are practically NOPs with respect to
2027 	 * hardware and software states.
2028 	 *
2029 	 * See also: Comment for clk_set_parent() below.
2030 	 */
2031 
2032 	/* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
2033 	if (core->flags & CLK_OPS_PARENT_ENABLE) {
2034 		clk_core_prepare_enable(old_parent);
2035 		clk_core_prepare_enable(parent);
2036 	}
2037 
2038 	/* migrate prepare count if > 0 */
2039 	if (core->prepare_count) {
2040 		clk_core_prepare_enable(parent);
2041 		clk_core_enable_lock(core);
2042 	}
2043 
2044 	/* update the clk tree topology */
2045 	flags = clk_enable_lock();
2046 	clk_reparent(core, parent);
2047 	clk_enable_unlock(flags);
2048 
2049 	return old_parent;
2050 }
2051 
__clk_set_parent_after(struct clk_core * core,struct clk_core * parent,struct clk_core * old_parent)2052 static void __clk_set_parent_after(struct clk_core *core,
2053 				   struct clk_core *parent,
2054 				   struct clk_core *old_parent)
2055 {
2056 	/*
2057 	 * Finish the migration of prepare state and undo the changes done
2058 	 * for preventing a race with clk_enable().
2059 	 */
2060 	if (core->prepare_count) {
2061 		clk_core_disable_lock(core);
2062 		clk_core_disable_unprepare(old_parent);
2063 	}
2064 
2065 	/* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
2066 	if (core->flags & CLK_OPS_PARENT_ENABLE) {
2067 		clk_core_disable_unprepare(parent);
2068 		clk_core_disable_unprepare(old_parent);
2069 	}
2070 }
2071 
__clk_set_parent(struct clk_core * core,struct clk_core * parent,u8 p_index)2072 static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
2073 			    u8 p_index)
2074 {
2075 	unsigned long flags;
2076 	int ret = 0;
2077 	struct clk_core *old_parent;
2078 
2079 	old_parent = __clk_set_parent_before(core, parent);
2080 
2081 	trace_clk_set_parent(core, parent);
2082 
2083 	/* change clock input source */
2084 	if (parent && core->ops->set_parent)
2085 		ret = core->ops->set_parent(core->hw, p_index);
2086 
2087 	trace_clk_set_parent_complete(core, parent);
2088 
2089 	if (ret) {
2090 		flags = clk_enable_lock();
2091 		clk_reparent(core, old_parent);
2092 		clk_enable_unlock(flags);
2093 
2094 		__clk_set_parent_after(core, old_parent, parent);
2095 
2096 		return ret;
2097 	}
2098 
2099 	__clk_set_parent_after(core, parent, old_parent);
2100 
2101 	return 0;
2102 }
2103 
2104 /**
2105  * __clk_speculate_rates
2106  * @core: first clk in the subtree
2107  * @parent_rate: the "future" rate of clk's parent
2108  *
2109  * Walks the subtree of clks starting with clk, speculating rates as it
2110  * goes and firing off PRE_RATE_CHANGE notifications as necessary.
2111  *
2112  * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
2113  * pre-rate change notifications and returns early if no clks in the
2114  * subtree have subscribed to the notifications.  Note that if a clk does not
2115  * implement the .recalc_rate callback then it is assumed that the clock will
2116  * take on the rate of its parent.
2117  */
__clk_speculate_rates(struct clk_core * core,unsigned long parent_rate)2118 static int __clk_speculate_rates(struct clk_core *core,
2119 				 unsigned long parent_rate)
2120 {
2121 	struct clk_core *child;
2122 	unsigned long new_rate;
2123 	int ret = NOTIFY_DONE;
2124 
2125 	lockdep_assert_held(&prepare_lock);
2126 
2127 	new_rate = clk_recalc(core, parent_rate);
2128 
2129 	/* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
2130 	if (core->notifier_count)
2131 		ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
2132 
2133 	if (ret & NOTIFY_STOP_MASK) {
2134 		pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
2135 				__func__, core->name, ret);
2136 		goto out;
2137 	}
2138 
2139 	hlist_for_each_entry(child, &core->children, child_node) {
2140 		ret = __clk_speculate_rates(child, new_rate);
2141 		if (ret & NOTIFY_STOP_MASK)
2142 			break;
2143 	}
2144 
2145 out:
2146 	return ret;
2147 }
2148 
clk_calc_subtree(struct clk_core * core,unsigned long new_rate,struct clk_core * new_parent,u8 p_index)2149 static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
2150 			     struct clk_core *new_parent, u8 p_index)
2151 {
2152 	struct clk_core *child;
2153 
2154 	core->new_rate = new_rate;
2155 	core->new_parent = new_parent;
2156 	core->new_parent_index = p_index;
2157 	/* include clk in new parent's PRE_RATE_CHANGE notifications */
2158 	core->new_child = NULL;
2159 	if (new_parent && new_parent != core->parent)
2160 		new_parent->new_child = core;
2161 
2162 	hlist_for_each_entry(child, &core->children, child_node) {
2163 		child->new_rate = clk_recalc(child, new_rate);
2164 		clk_calc_subtree(child, child->new_rate, NULL, 0);
2165 	}
2166 }
2167 
2168 /*
2169  * calculate the new rates returning the topmost clock that has to be
2170  * changed.
2171  */
clk_calc_new_rates(struct clk_core * core,unsigned long rate)2172 static struct clk_core *clk_calc_new_rates(struct clk_core *core,
2173 					   unsigned long rate)
2174 {
2175 	struct clk_core *top = core;
2176 	struct clk_core *old_parent, *parent;
2177 	unsigned long best_parent_rate = 0;
2178 	unsigned long new_rate;
2179 	unsigned long min_rate;
2180 	unsigned long max_rate;
2181 	int p_index = 0;
2182 	long ret;
2183 
2184 	/* sanity */
2185 	if (IS_ERR_OR_NULL(core))
2186 		return NULL;
2187 
2188 	/* save parent rate, if it exists */
2189 	parent = old_parent = core->parent;
2190 	if (parent)
2191 		best_parent_rate = parent->rate;
2192 
2193 	clk_core_get_boundaries(core, &min_rate, &max_rate);
2194 
2195 	/* find the closest rate and parent clk/rate */
2196 	if (clk_core_can_round(core)) {
2197 		struct clk_rate_request req;
2198 
2199 		clk_core_init_rate_req(core, &req, rate);
2200 
2201 		trace_clk_rate_request_start(&req);
2202 
2203 		ret = clk_core_determine_round_nolock(core, &req);
2204 		if (ret < 0)
2205 			return NULL;
2206 
2207 		trace_clk_rate_request_done(&req);
2208 
2209 		best_parent_rate = req.best_parent_rate;
2210 		new_rate = req.rate;
2211 		parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
2212 
2213 		if (new_rate < min_rate || new_rate > max_rate)
2214 			return NULL;
2215 	} else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
2216 		/* pass-through clock without adjustable parent */
2217 		core->new_rate = core->rate;
2218 		return NULL;
2219 	} else {
2220 		/* pass-through clock with adjustable parent */
2221 		top = clk_calc_new_rates(parent, rate);
2222 		new_rate = parent->new_rate;
2223 		goto out;
2224 	}
2225 
2226 	/* some clocks must be gated to change parent */
2227 	if (parent != old_parent &&
2228 	    (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
2229 		pr_debug("%s: %s not gated but wants to reparent\n",
2230 			 __func__, core->name);
2231 		return NULL;
2232 	}
2233 
2234 	/* try finding the new parent index */
2235 	if (parent && core->num_parents > 1) {
2236 		p_index = clk_fetch_parent_index(core, parent);
2237 		if (p_index < 0) {
2238 			pr_debug("%s: clk %s can not be parent of clk %s\n",
2239 				 __func__, parent->name, core->name);
2240 			return NULL;
2241 		}
2242 	}
2243 
2244 	if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
2245 	    best_parent_rate != parent->rate)
2246 		top = clk_calc_new_rates(parent, best_parent_rate);
2247 
2248 out:
2249 	clk_calc_subtree(core, new_rate, parent, p_index);
2250 
2251 	return top;
2252 }
2253 
2254 /*
2255  * Notify about rate changes in a subtree. Always walk down the whole tree
2256  * so that in case of an error we can walk down the whole tree again and
2257  * abort the change.
2258  */
clk_propagate_rate_change(struct clk_core * core,unsigned long event)2259 static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
2260 						  unsigned long event)
2261 {
2262 	struct clk_core *child, *tmp_clk, *fail_clk = NULL;
2263 	int ret = NOTIFY_DONE;
2264 
2265 	if (core->rate == core->new_rate)
2266 		return NULL;
2267 
2268 	if (core->notifier_count) {
2269 		ret = __clk_notify(core, event, core->rate, core->new_rate);
2270 		if (ret & NOTIFY_STOP_MASK)
2271 			fail_clk = core;
2272 	}
2273 
2274 	hlist_for_each_entry(child, &core->children, child_node) {
2275 		/* Skip children who will be reparented to another clock */
2276 		if (child->new_parent && child->new_parent != core)
2277 			continue;
2278 		tmp_clk = clk_propagate_rate_change(child, event);
2279 		if (tmp_clk)
2280 			fail_clk = tmp_clk;
2281 	}
2282 
2283 	/* handle the new child who might not be in core->children yet */
2284 	if (core->new_child) {
2285 		tmp_clk = clk_propagate_rate_change(core->new_child, event);
2286 		if (tmp_clk)
2287 			fail_clk = tmp_clk;
2288 	}
2289 
2290 	return fail_clk;
2291 }
2292 
2293 /*
2294  * walk down a subtree and set the new rates notifying the rate
2295  * change on the way
2296  */
clk_change_rate(struct clk_core * core)2297 static void clk_change_rate(struct clk_core *core)
2298 {
2299 	struct clk_core *child;
2300 	struct hlist_node *tmp;
2301 	unsigned long old_rate;
2302 	unsigned long best_parent_rate = 0;
2303 	bool skip_set_rate = false;
2304 	struct clk_core *old_parent;
2305 	struct clk_core *parent = NULL;
2306 
2307 	old_rate = core->rate;
2308 
2309 	if (core->new_parent) {
2310 		parent = core->new_parent;
2311 		best_parent_rate = core->new_parent->rate;
2312 	} else if (core->parent) {
2313 		parent = core->parent;
2314 		best_parent_rate = core->parent->rate;
2315 	}
2316 
2317 	if (clk_pm_runtime_get(core))
2318 		return;
2319 
2320 	if (core->flags & CLK_SET_RATE_UNGATE) {
2321 		clk_core_prepare(core);
2322 		clk_core_enable_lock(core);
2323 	}
2324 
2325 	if (core->new_parent && core->new_parent != core->parent) {
2326 		old_parent = __clk_set_parent_before(core, core->new_parent);
2327 		trace_clk_set_parent(core, core->new_parent);
2328 
2329 		if (core->ops->set_rate_and_parent) {
2330 			skip_set_rate = true;
2331 			core->ops->set_rate_and_parent(core->hw, core->new_rate,
2332 					best_parent_rate,
2333 					core->new_parent_index);
2334 		} else if (core->ops->set_parent) {
2335 			core->ops->set_parent(core->hw, core->new_parent_index);
2336 		}
2337 
2338 		trace_clk_set_parent_complete(core, core->new_parent);
2339 		__clk_set_parent_after(core, core->new_parent, old_parent);
2340 	}
2341 
2342 	if (core->flags & CLK_OPS_PARENT_ENABLE)
2343 		clk_core_prepare_enable(parent);
2344 
2345 	trace_clk_set_rate(core, core->new_rate);
2346 
2347 	if (!skip_set_rate && core->ops->set_rate)
2348 		core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2349 
2350 	trace_clk_set_rate_complete(core, core->new_rate);
2351 
2352 	core->rate = clk_recalc(core, best_parent_rate);
2353 
2354 	if (core->flags & CLK_SET_RATE_UNGATE) {
2355 		clk_core_disable_lock(core);
2356 		clk_core_unprepare(core);
2357 	}
2358 
2359 	if (core->flags & CLK_OPS_PARENT_ENABLE)
2360 		clk_core_disable_unprepare(parent);
2361 
2362 	if (core->notifier_count && old_rate != core->rate)
2363 		__clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2364 
2365 	if (core->flags & CLK_RECALC_NEW_RATES)
2366 		(void)clk_calc_new_rates(core, core->new_rate);
2367 
2368 	/*
2369 	 * Use safe iteration, as change_rate can actually swap parents
2370 	 * for certain clock types.
2371 	 */
2372 	hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2373 		/* Skip children who will be reparented to another clock */
2374 		if (child->new_parent && child->new_parent != core)
2375 			continue;
2376 		clk_change_rate(child);
2377 	}
2378 
2379 	/* handle the new child who might not be in core->children yet */
2380 	if (core->new_child)
2381 		clk_change_rate(core->new_child);
2382 
2383 	clk_pm_runtime_put(core);
2384 }
2385 
clk_core_req_round_rate_nolock(struct clk_core * core,unsigned long req_rate)2386 static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2387 						     unsigned long req_rate)
2388 {
2389 	int ret, cnt;
2390 	struct clk_rate_request req;
2391 
2392 	lockdep_assert_held(&prepare_lock);
2393 
2394 	if (!core)
2395 		return 0;
2396 
2397 	/* simulate what the rate would be if it could be freely set */
2398 	cnt = clk_core_rate_nuke_protect(core);
2399 	if (cnt < 0)
2400 		return cnt;
2401 
2402 	clk_core_init_rate_req(core, &req, req_rate);
2403 
2404 	trace_clk_rate_request_start(&req);
2405 
2406 	ret = clk_core_round_rate_nolock(core, &req);
2407 
2408 	trace_clk_rate_request_done(&req);
2409 
2410 	/* restore the protection */
2411 	clk_core_rate_restore_protect(core, cnt);
2412 
2413 	return ret ? 0 : req.rate;
2414 }
2415 
clk_core_set_rate_nolock(struct clk_core * core,unsigned long req_rate)2416 static int clk_core_set_rate_nolock(struct clk_core *core,
2417 				    unsigned long req_rate)
2418 {
2419 	struct clk_core *top, *fail_clk;
2420 	unsigned long rate;
2421 	int ret;
2422 
2423 	if (!core)
2424 		return 0;
2425 
2426 	rate = clk_core_req_round_rate_nolock(core, req_rate);
2427 
2428 	/* bail early if nothing to do */
2429 	if (rate == clk_core_get_rate_nolock(core))
2430 		return 0;
2431 
2432 	/* fail on a direct rate set of a protected provider */
2433 	if (clk_core_rate_is_protected(core))
2434 		return -EBUSY;
2435 
2436 	/* calculate new rates and get the topmost changed clock */
2437 	top = clk_calc_new_rates(core, req_rate);
2438 	if (!top)
2439 		return -EINVAL;
2440 
2441 	ret = clk_pm_runtime_get(core);
2442 	if (ret)
2443 		return ret;
2444 
2445 	/* notify that we are about to change rates */
2446 	fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2447 	if (fail_clk) {
2448 		pr_debug("%s: failed to set %s rate\n", __func__,
2449 				fail_clk->name);
2450 		clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2451 		ret = -EBUSY;
2452 		goto err;
2453 	}
2454 
2455 	/* change the rates */
2456 	clk_change_rate(top);
2457 
2458 	core->req_rate = req_rate;
2459 err:
2460 	clk_pm_runtime_put(core);
2461 
2462 	return ret;
2463 }
2464 
2465 /**
2466  * clk_set_rate - specify a new rate for clk
2467  * @clk: the clk whose rate is being changed
2468  * @rate: the new rate for clk
2469  *
2470  * In the simplest case clk_set_rate will only adjust the rate of clk.
2471  *
2472  * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2473  * propagate up to clk's parent; whether or not this happens depends on the
2474  * outcome of clk's .round_rate implementation.  If *parent_rate is unchanged
2475  * after calling .round_rate then upstream parent propagation is ignored.  If
2476  * *parent_rate comes back with a new rate for clk's parent then we propagate
2477  * up to clk's parent and set its rate.  Upward propagation will continue
2478  * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2479  * .round_rate stops requesting changes to clk's parent_rate.
2480  *
2481  * Rate changes are accomplished via tree traversal that also recalculates the
2482  * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2483  *
2484  * Returns 0 on success, -EERROR otherwise.
2485  */
clk_set_rate(struct clk * clk,unsigned long rate)2486 int clk_set_rate(struct clk *clk, unsigned long rate)
2487 {
2488 	int ret;
2489 
2490 	if (!clk)
2491 		return 0;
2492 
2493 	/* prevent racing with updates to the clock topology */
2494 	clk_prepare_lock();
2495 
2496 	if (clk->exclusive_count)
2497 		clk_core_rate_unprotect(clk->core);
2498 
2499 	ret = clk_core_set_rate_nolock(clk->core, rate);
2500 
2501 	if (clk->exclusive_count)
2502 		clk_core_rate_protect(clk->core);
2503 
2504 	clk_prepare_unlock();
2505 
2506 	return ret;
2507 }
2508 EXPORT_SYMBOL_GPL(clk_set_rate);
2509 
2510 /**
2511  * clk_set_rate_exclusive - specify a new rate and get exclusive control
2512  * @clk: the clk whose rate is being changed
2513  * @rate: the new rate for clk
2514  *
2515  * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2516  * within a critical section
2517  *
2518  * This can be used initially to ensure that at least 1 consumer is
2519  * satisfied when several consumers are competing for exclusivity over the
2520  * same clock provider.
2521  *
2522  * The exclusivity is not applied if setting the rate failed.
2523  *
2524  * Calls to clk_rate_exclusive_get() should be balanced with calls to
2525  * clk_rate_exclusive_put().
2526  *
2527  * Returns 0 on success, -EERROR otherwise.
2528  */
clk_set_rate_exclusive(struct clk * clk,unsigned long rate)2529 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2530 {
2531 	int ret;
2532 
2533 	if (!clk)
2534 		return 0;
2535 
2536 	/* prevent racing with updates to the clock topology */
2537 	clk_prepare_lock();
2538 
2539 	/*
2540 	 * The temporary protection removal is not here, on purpose
2541 	 * This function is meant to be used instead of clk_rate_protect,
2542 	 * so before the consumer code path protect the clock provider
2543 	 */
2544 
2545 	ret = clk_core_set_rate_nolock(clk->core, rate);
2546 	if (!ret) {
2547 		clk_core_rate_protect(clk->core);
2548 		clk->exclusive_count++;
2549 	}
2550 
2551 	clk_prepare_unlock();
2552 
2553 	return ret;
2554 }
2555 EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2556 
clk_set_rate_range_nolock(struct clk * clk,unsigned long min,unsigned long max)2557 static int clk_set_rate_range_nolock(struct clk *clk,
2558 				     unsigned long min,
2559 				     unsigned long max)
2560 {
2561 	int ret = 0;
2562 	unsigned long old_min, old_max, rate;
2563 
2564 	lockdep_assert_held(&prepare_lock);
2565 
2566 	if (!clk)
2567 		return 0;
2568 
2569 	trace_clk_set_rate_range(clk->core, min, max);
2570 
2571 	if (min > max) {
2572 		pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2573 		       __func__, clk->core->name, clk->dev_id, clk->con_id,
2574 		       min, max);
2575 		return -EINVAL;
2576 	}
2577 
2578 	if (clk->exclusive_count)
2579 		clk_core_rate_unprotect(clk->core);
2580 
2581 	/* Save the current values in case we need to rollback the change */
2582 	old_min = clk->min_rate;
2583 	old_max = clk->max_rate;
2584 	clk->min_rate = min;
2585 	clk->max_rate = max;
2586 
2587 	if (!clk_core_check_boundaries(clk->core, min, max)) {
2588 		ret = -EINVAL;
2589 		goto out;
2590 	}
2591 
2592 	rate = clk->core->req_rate;
2593 	if (clk->core->flags & CLK_GET_RATE_NOCACHE)
2594 		rate = clk_core_get_rate_recalc(clk->core);
2595 
2596 	/*
2597 	 * Since the boundaries have been changed, let's give the
2598 	 * opportunity to the provider to adjust the clock rate based on
2599 	 * the new boundaries.
2600 	 *
2601 	 * We also need to handle the case where the clock is currently
2602 	 * outside of the boundaries. Clamping the last requested rate
2603 	 * to the current minimum and maximum will also handle this.
2604 	 *
2605 	 * FIXME:
2606 	 * There is a catch. It may fail for the usual reason (clock
2607 	 * broken, clock protected, etc) but also because:
2608 	 * - round_rate() was not favorable and fell on the wrong
2609 	 *   side of the boundary
2610 	 * - the determine_rate() callback does not really check for
2611 	 *   this corner case when determining the rate
2612 	 */
2613 	rate = clamp(rate, min, max);
2614 	ret = clk_core_set_rate_nolock(clk->core, rate);
2615 	if (ret) {
2616 		/* rollback the changes */
2617 		clk->min_rate = old_min;
2618 		clk->max_rate = old_max;
2619 	}
2620 
2621 out:
2622 	if (clk->exclusive_count)
2623 		clk_core_rate_protect(clk->core);
2624 
2625 	return ret;
2626 }
2627 
2628 /**
2629  * clk_set_rate_range - set a rate range for a clock source
2630  * @clk: clock source
2631  * @min: desired minimum clock rate in Hz, inclusive
2632  * @max: desired maximum clock rate in Hz, inclusive
2633  *
2634  * Return: 0 for success or negative errno on failure.
2635  */
clk_set_rate_range(struct clk * clk,unsigned long min,unsigned long max)2636 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2637 {
2638 	int ret;
2639 
2640 	if (!clk)
2641 		return 0;
2642 
2643 	clk_prepare_lock();
2644 
2645 	ret = clk_set_rate_range_nolock(clk, min, max);
2646 
2647 	clk_prepare_unlock();
2648 
2649 	return ret;
2650 }
2651 EXPORT_SYMBOL_GPL(clk_set_rate_range);
2652 
2653 /**
2654  * clk_set_min_rate - set a minimum clock rate for a clock source
2655  * @clk: clock source
2656  * @rate: desired minimum clock rate in Hz, inclusive
2657  *
2658  * Returns success (0) or negative errno.
2659  */
clk_set_min_rate(struct clk * clk,unsigned long rate)2660 int clk_set_min_rate(struct clk *clk, unsigned long rate)
2661 {
2662 	if (!clk)
2663 		return 0;
2664 
2665 	trace_clk_set_min_rate(clk->core, rate);
2666 
2667 	return clk_set_rate_range(clk, rate, clk->max_rate);
2668 }
2669 EXPORT_SYMBOL_GPL(clk_set_min_rate);
2670 
2671 /**
2672  * clk_set_max_rate - set a maximum clock rate for a clock source
2673  * @clk: clock source
2674  * @rate: desired maximum clock rate in Hz, inclusive
2675  *
2676  * Returns success (0) or negative errno.
2677  */
clk_set_max_rate(struct clk * clk,unsigned long rate)2678 int clk_set_max_rate(struct clk *clk, unsigned long rate)
2679 {
2680 	if (!clk)
2681 		return 0;
2682 
2683 	trace_clk_set_max_rate(clk->core, rate);
2684 
2685 	return clk_set_rate_range(clk, clk->min_rate, rate);
2686 }
2687 EXPORT_SYMBOL_GPL(clk_set_max_rate);
2688 
2689 /**
2690  * clk_get_parent - return the parent of a clk
2691  * @clk: the clk whose parent gets returned
2692  *
2693  * Simply returns clk->parent.  Returns NULL if clk is NULL.
2694  */
clk_get_parent(struct clk * clk)2695 struct clk *clk_get_parent(struct clk *clk)
2696 {
2697 	struct clk *parent;
2698 
2699 	if (!clk)
2700 		return NULL;
2701 
2702 	clk_prepare_lock();
2703 	/* TODO: Create a per-user clk and change callers to call clk_put */
2704 	parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2705 	clk_prepare_unlock();
2706 
2707 	return parent;
2708 }
2709 EXPORT_SYMBOL_GPL(clk_get_parent);
2710 
__clk_init_parent(struct clk_core * core)2711 static struct clk_core *__clk_init_parent(struct clk_core *core)
2712 {
2713 	u8 index = 0;
2714 
2715 	if (core->num_parents > 1 && core->ops->get_parent)
2716 		index = core->ops->get_parent(core->hw);
2717 
2718 	return clk_core_get_parent_by_index(core, index);
2719 }
2720 
clk_core_reparent(struct clk_core * core,struct clk_core * new_parent)2721 static void clk_core_reparent(struct clk_core *core,
2722 				  struct clk_core *new_parent)
2723 {
2724 	clk_reparent(core, new_parent);
2725 	__clk_recalc_accuracies(core);
2726 	__clk_recalc_rates(core, true, POST_RATE_CHANGE);
2727 }
2728 
clk_hw_reparent(struct clk_hw * hw,struct clk_hw * new_parent)2729 void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2730 {
2731 	if (!hw)
2732 		return;
2733 
2734 	clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2735 }
2736 
2737 /**
2738  * clk_has_parent - check if a clock is a possible parent for another
2739  * @clk: clock source
2740  * @parent: parent clock source
2741  *
2742  * This function can be used in drivers that need to check that a clock can be
2743  * the parent of another without actually changing the parent.
2744  *
2745  * Returns true if @parent is a possible parent for @clk, false otherwise.
2746  */
clk_has_parent(const struct clk * clk,const struct clk * parent)2747 bool clk_has_parent(const struct clk *clk, const struct clk *parent)
2748 {
2749 	/* NULL clocks should be nops, so return success if either is NULL. */
2750 	if (!clk || !parent)
2751 		return true;
2752 
2753 	return clk_core_has_parent(clk->core, parent->core);
2754 }
2755 EXPORT_SYMBOL_GPL(clk_has_parent);
2756 
clk_core_set_parent_nolock(struct clk_core * core,struct clk_core * parent)2757 static int clk_core_set_parent_nolock(struct clk_core *core,
2758 				      struct clk_core *parent)
2759 {
2760 	int ret = 0;
2761 	int p_index = 0;
2762 	unsigned long p_rate = 0;
2763 
2764 	lockdep_assert_held(&prepare_lock);
2765 
2766 	if (!core)
2767 		return 0;
2768 
2769 	if (core->parent == parent)
2770 		return 0;
2771 
2772 	/* verify ops for multi-parent clks */
2773 	if (core->num_parents > 1 && !core->ops->set_parent)
2774 		return -EPERM;
2775 
2776 	/* check that we are allowed to re-parent if the clock is in use */
2777 	if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2778 		return -EBUSY;
2779 
2780 	if (clk_core_rate_is_protected(core))
2781 		return -EBUSY;
2782 
2783 	/* try finding the new parent index */
2784 	if (parent) {
2785 		p_index = clk_fetch_parent_index(core, parent);
2786 		if (p_index < 0) {
2787 			pr_debug("%s: clk %s can not be parent of clk %s\n",
2788 					__func__, parent->name, core->name);
2789 			return p_index;
2790 		}
2791 		p_rate = parent->rate;
2792 	}
2793 
2794 	ret = clk_pm_runtime_get(core);
2795 	if (ret)
2796 		return ret;
2797 
2798 	/* propagate PRE_RATE_CHANGE notifications */
2799 	ret = __clk_speculate_rates(core, p_rate);
2800 
2801 	/* abort if a driver objects */
2802 	if (ret & NOTIFY_STOP_MASK)
2803 		goto runtime_put;
2804 
2805 	/* do the re-parent */
2806 	ret = __clk_set_parent(core, parent, p_index);
2807 
2808 	/* propagate rate an accuracy recalculation accordingly */
2809 	if (ret) {
2810 		__clk_recalc_rates(core, true, ABORT_RATE_CHANGE);
2811 	} else {
2812 		__clk_recalc_rates(core, true, POST_RATE_CHANGE);
2813 		__clk_recalc_accuracies(core);
2814 	}
2815 
2816 runtime_put:
2817 	clk_pm_runtime_put(core);
2818 
2819 	return ret;
2820 }
2821 
clk_hw_set_parent(struct clk_hw * hw,struct clk_hw * parent)2822 int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2823 {
2824 	return clk_core_set_parent_nolock(hw->core, parent->core);
2825 }
2826 EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2827 
2828 /**
2829  * clk_set_parent - switch the parent of a mux clk
2830  * @clk: the mux clk whose input we are switching
2831  * @parent: the new input to clk
2832  *
2833  * Re-parent clk to use parent as its new input source.  If clk is in
2834  * prepared state, the clk will get enabled for the duration of this call. If
2835  * that's not acceptable for a specific clk (Eg: the consumer can't handle
2836  * that, the reparenting is glitchy in hardware, etc), use the
2837  * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2838  *
2839  * After successfully changing clk's parent clk_set_parent will update the
2840  * clk topology, sysfs topology and propagate rate recalculation via
2841  * __clk_recalc_rates.
2842  *
2843  * Returns 0 on success, -EERROR otherwise.
2844  */
clk_set_parent(struct clk * clk,struct clk * parent)2845 int clk_set_parent(struct clk *clk, struct clk *parent)
2846 {
2847 	int ret;
2848 
2849 	if (!clk)
2850 		return 0;
2851 
2852 	clk_prepare_lock();
2853 
2854 	if (clk->exclusive_count)
2855 		clk_core_rate_unprotect(clk->core);
2856 
2857 	ret = clk_core_set_parent_nolock(clk->core,
2858 					 parent ? parent->core : NULL);
2859 
2860 	if (clk->exclusive_count)
2861 		clk_core_rate_protect(clk->core);
2862 
2863 	clk_prepare_unlock();
2864 
2865 	return ret;
2866 }
2867 EXPORT_SYMBOL_GPL(clk_set_parent);
2868 
clk_core_set_phase_nolock(struct clk_core * core,int degrees)2869 static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2870 {
2871 	int ret = -EINVAL;
2872 
2873 	lockdep_assert_held(&prepare_lock);
2874 
2875 	if (!core)
2876 		return 0;
2877 
2878 	if (clk_core_rate_is_protected(core))
2879 		return -EBUSY;
2880 
2881 	trace_clk_set_phase(core, degrees);
2882 
2883 	if (core->ops->set_phase) {
2884 		ret = core->ops->set_phase(core->hw, degrees);
2885 		if (!ret)
2886 			core->phase = degrees;
2887 	}
2888 
2889 	trace_clk_set_phase_complete(core, degrees);
2890 
2891 	return ret;
2892 }
2893 
2894 /**
2895  * clk_set_phase - adjust the phase shift of a clock signal
2896  * @clk: clock signal source
2897  * @degrees: number of degrees the signal is shifted
2898  *
2899  * Shifts the phase of a clock signal by the specified
2900  * degrees. Returns 0 on success, -EERROR otherwise.
2901  *
2902  * This function makes no distinction about the input or reference
2903  * signal that we adjust the clock signal phase against. For example
2904  * phase locked-loop clock signal generators we may shift phase with
2905  * respect to feedback clock signal input, but for other cases the
2906  * clock phase may be shifted with respect to some other, unspecified
2907  * signal.
2908  *
2909  * Additionally the concept of phase shift does not propagate through
2910  * the clock tree hierarchy, which sets it apart from clock rates and
2911  * clock accuracy. A parent clock phase attribute does not have an
2912  * impact on the phase attribute of a child clock.
2913  */
clk_set_phase(struct clk * clk,int degrees)2914 int clk_set_phase(struct clk *clk, int degrees)
2915 {
2916 	int ret;
2917 
2918 	if (!clk)
2919 		return 0;
2920 
2921 	/* sanity check degrees */
2922 	degrees %= 360;
2923 	if (degrees < 0)
2924 		degrees += 360;
2925 
2926 	clk_prepare_lock();
2927 
2928 	if (clk->exclusive_count)
2929 		clk_core_rate_unprotect(clk->core);
2930 
2931 	ret = clk_core_set_phase_nolock(clk->core, degrees);
2932 
2933 	if (clk->exclusive_count)
2934 		clk_core_rate_protect(clk->core);
2935 
2936 	clk_prepare_unlock();
2937 
2938 	return ret;
2939 }
2940 EXPORT_SYMBOL_GPL(clk_set_phase);
2941 
clk_core_get_phase(struct clk_core * core)2942 static int clk_core_get_phase(struct clk_core *core)
2943 {
2944 	int ret;
2945 
2946 	lockdep_assert_held(&prepare_lock);
2947 	if (!core->ops->get_phase)
2948 		return 0;
2949 
2950 	/* Always try to update cached phase if possible */
2951 	ret = core->ops->get_phase(core->hw);
2952 	if (ret >= 0)
2953 		core->phase = ret;
2954 
2955 	return ret;
2956 }
2957 
2958 /**
2959  * clk_get_phase - return the phase shift of a clock signal
2960  * @clk: clock signal source
2961  *
2962  * Returns the phase shift of a clock node in degrees, otherwise returns
2963  * -EERROR.
2964  */
clk_get_phase(struct clk * clk)2965 int clk_get_phase(struct clk *clk)
2966 {
2967 	int ret;
2968 
2969 	if (!clk)
2970 		return 0;
2971 
2972 	clk_prepare_lock();
2973 	ret = clk_core_get_phase(clk->core);
2974 	clk_prepare_unlock();
2975 
2976 	return ret;
2977 }
2978 EXPORT_SYMBOL_GPL(clk_get_phase);
2979 
clk_core_reset_duty_cycle_nolock(struct clk_core * core)2980 static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2981 {
2982 	/* Assume a default value of 50% */
2983 	core->duty.num = 1;
2984 	core->duty.den = 2;
2985 }
2986 
2987 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2988 
clk_core_update_duty_cycle_nolock(struct clk_core * core)2989 static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2990 {
2991 	struct clk_duty *duty = &core->duty;
2992 	int ret = 0;
2993 
2994 	if (!core->ops->get_duty_cycle)
2995 		return clk_core_update_duty_cycle_parent_nolock(core);
2996 
2997 	ret = core->ops->get_duty_cycle(core->hw, duty);
2998 	if (ret)
2999 		goto reset;
3000 
3001 	/* Don't trust the clock provider too much */
3002 	if (duty->den == 0 || duty->num > duty->den) {
3003 		ret = -EINVAL;
3004 		goto reset;
3005 	}
3006 
3007 	return 0;
3008 
3009 reset:
3010 	clk_core_reset_duty_cycle_nolock(core);
3011 	return ret;
3012 }
3013 
clk_core_update_duty_cycle_parent_nolock(struct clk_core * core)3014 static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
3015 {
3016 	int ret = 0;
3017 
3018 	if (core->parent &&
3019 	    core->flags & CLK_DUTY_CYCLE_PARENT) {
3020 		ret = clk_core_update_duty_cycle_nolock(core->parent);
3021 		memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3022 	} else {
3023 		clk_core_reset_duty_cycle_nolock(core);
3024 	}
3025 
3026 	return ret;
3027 }
3028 
3029 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3030 						 struct clk_duty *duty);
3031 
clk_core_set_duty_cycle_nolock(struct clk_core * core,struct clk_duty * duty)3032 static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
3033 					  struct clk_duty *duty)
3034 {
3035 	int ret;
3036 
3037 	lockdep_assert_held(&prepare_lock);
3038 
3039 	if (clk_core_rate_is_protected(core))
3040 		return -EBUSY;
3041 
3042 	trace_clk_set_duty_cycle(core, duty);
3043 
3044 	if (!core->ops->set_duty_cycle)
3045 		return clk_core_set_duty_cycle_parent_nolock(core, duty);
3046 
3047 	ret = core->ops->set_duty_cycle(core->hw, duty);
3048 	if (!ret)
3049 		memcpy(&core->duty, duty, sizeof(*duty));
3050 
3051 	trace_clk_set_duty_cycle_complete(core, duty);
3052 
3053 	return ret;
3054 }
3055 
clk_core_set_duty_cycle_parent_nolock(struct clk_core * core,struct clk_duty * duty)3056 static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3057 						 struct clk_duty *duty)
3058 {
3059 	int ret = 0;
3060 
3061 	if (core->parent &&
3062 	    core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
3063 		ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
3064 		memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3065 	}
3066 
3067 	return ret;
3068 }
3069 
3070 /**
3071  * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
3072  * @clk: clock signal source
3073  * @num: numerator of the duty cycle ratio to be applied
3074  * @den: denominator of the duty cycle ratio to be applied
3075  *
3076  * Apply the duty cycle ratio if the ratio is valid and the clock can
3077  * perform this operation
3078  *
3079  * Returns (0) on success, a negative errno otherwise.
3080  */
clk_set_duty_cycle(struct clk * clk,unsigned int num,unsigned int den)3081 int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
3082 {
3083 	int ret;
3084 	struct clk_duty duty;
3085 
3086 	if (!clk)
3087 		return 0;
3088 
3089 	/* sanity check the ratio */
3090 	if (den == 0 || num > den)
3091 		return -EINVAL;
3092 
3093 	duty.num = num;
3094 	duty.den = den;
3095 
3096 	clk_prepare_lock();
3097 
3098 	if (clk->exclusive_count)
3099 		clk_core_rate_unprotect(clk->core);
3100 
3101 	ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
3102 
3103 	if (clk->exclusive_count)
3104 		clk_core_rate_protect(clk->core);
3105 
3106 	clk_prepare_unlock();
3107 
3108 	return ret;
3109 }
3110 EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
3111 
clk_core_get_scaled_duty_cycle(struct clk_core * core,unsigned int scale)3112 static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
3113 					  unsigned int scale)
3114 {
3115 	struct clk_duty *duty = &core->duty;
3116 	int ret;
3117 
3118 	clk_prepare_lock();
3119 
3120 	ret = clk_core_update_duty_cycle_nolock(core);
3121 	if (!ret)
3122 		ret = mult_frac(scale, duty->num, duty->den);
3123 
3124 	clk_prepare_unlock();
3125 
3126 	return ret;
3127 }
3128 
3129 /**
3130  * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
3131  * @clk: clock signal source
3132  * @scale: scaling factor to be applied to represent the ratio as an integer
3133  *
3134  * Returns the duty cycle ratio of a clock node multiplied by the provided
3135  * scaling factor, or negative errno on error.
3136  */
clk_get_scaled_duty_cycle(struct clk * clk,unsigned int scale)3137 int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
3138 {
3139 	if (!clk)
3140 		return 0;
3141 
3142 	return clk_core_get_scaled_duty_cycle(clk->core, scale);
3143 }
3144 EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
3145 
3146 /**
3147  * clk_is_match - check if two clk's point to the same hardware clock
3148  * @p: clk compared against q
3149  * @q: clk compared against p
3150  *
3151  * Returns true if the two struct clk pointers both point to the same hardware
3152  * clock node. Put differently, returns true if struct clk *p and struct clk *q
3153  * share the same struct clk_core object.
3154  *
3155  * Returns false otherwise. Note that two NULL clks are treated as matching.
3156  */
clk_is_match(const struct clk * p,const struct clk * q)3157 bool clk_is_match(const struct clk *p, const struct clk *q)
3158 {
3159 	/* trivial case: identical struct clk's or both NULL */
3160 	if (p == q)
3161 		return true;
3162 
3163 	/* true if clk->core pointers match. Avoid dereferencing garbage */
3164 	if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
3165 		if (p->core == q->core)
3166 			return true;
3167 
3168 	return false;
3169 }
3170 EXPORT_SYMBOL_GPL(clk_is_match);
3171 
3172 /***        debugfs support        ***/
3173 
3174 #ifdef CONFIG_DEBUG_FS
3175 #include <linux/debugfs.h>
3176 
3177 static struct dentry *rootdir;
3178 static int inited = 0;
3179 static DEFINE_MUTEX(clk_debug_lock);
3180 static HLIST_HEAD(clk_debug_list);
3181 
3182 static struct hlist_head *orphan_list[] = {
3183 	&clk_orphan_list,
3184 	NULL,
3185 };
3186 
clk_summary_show_one(struct seq_file * s,struct clk_core * c,int level)3187 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
3188 				 int level)
3189 {
3190 	int phase;
3191 
3192 	seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ",
3193 		   level * 3 + 1, "",
3194 		   30 - level * 3, c->name,
3195 		   c->enable_count, c->prepare_count, c->protect_count,
3196 		   clk_core_get_rate_recalc(c),
3197 		   clk_core_get_accuracy_recalc(c));
3198 
3199 	phase = clk_core_get_phase(c);
3200 	if (phase >= 0)
3201 		seq_printf(s, "%5d", phase);
3202 	else
3203 		seq_puts(s, "-----");
3204 
3205 	seq_printf(s, " %6d", clk_core_get_scaled_duty_cycle(c, 100000));
3206 
3207 	if (c->ops->is_enabled)
3208 		seq_printf(s, " %9c\n", clk_core_is_enabled(c) ? 'Y' : 'N');
3209 	else if (!c->ops->enable)
3210 		seq_printf(s, " %9c\n", 'Y');
3211 	else
3212 		seq_printf(s, " %9c\n", '?');
3213 }
3214 
clk_summary_show_subtree(struct seq_file * s,struct clk_core * c,int level)3215 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
3216 				     int level)
3217 {
3218 	struct clk_core *child;
3219 
3220 	clk_pm_runtime_get(c);
3221 	clk_summary_show_one(s, c, level);
3222 	clk_pm_runtime_put(c);
3223 
3224 	hlist_for_each_entry(child, &c->children, child_node)
3225 		clk_summary_show_subtree(s, child, level + 1);
3226 }
3227 
clk_summary_show(struct seq_file * s,void * data)3228 static int clk_summary_show(struct seq_file *s, void *data)
3229 {
3230 	struct clk_core *c;
3231 	struct hlist_head **lists = s->private;
3232 
3233 	seq_puts(s, "                                 enable  prepare  protect                                duty  hardware\n");
3234 	seq_puts(s, "   clock                          count    count    count        rate   accuracy phase  cycle    enable\n");
3235 	seq_puts(s, "-------------------------------------------------------------------------------------------------------\n");
3236 
3237 	clk_prepare_lock();
3238 
3239 	for (; *lists; lists++)
3240 		hlist_for_each_entry(c, *lists, child_node)
3241 			clk_summary_show_subtree(s, c, 0);
3242 
3243 	clk_prepare_unlock();
3244 
3245 	return 0;
3246 }
3247 DEFINE_SHOW_ATTRIBUTE(clk_summary);
3248 
clk_dump_one(struct seq_file * s,struct clk_core * c,int level)3249 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
3250 {
3251 	int phase;
3252 	unsigned long min_rate, max_rate;
3253 
3254 	clk_core_get_boundaries(c, &min_rate, &max_rate);
3255 
3256 	/* This should be JSON format, i.e. elements separated with a comma */
3257 	seq_printf(s, "\"%s\": { ", c->name);
3258 	seq_printf(s, "\"enable_count\": %d,", c->enable_count);
3259 	seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
3260 	seq_printf(s, "\"protect_count\": %d,", c->protect_count);
3261 	seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
3262 	seq_printf(s, "\"min_rate\": %lu,", min_rate);
3263 	seq_printf(s, "\"max_rate\": %lu,", max_rate);
3264 	seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
3265 	phase = clk_core_get_phase(c);
3266 	if (phase >= 0)
3267 		seq_printf(s, "\"phase\": %d,", phase);
3268 	seq_printf(s, "\"duty_cycle\": %u",
3269 		   clk_core_get_scaled_duty_cycle(c, 100000));
3270 }
3271 
clk_dump_subtree(struct seq_file * s,struct clk_core * c,int level)3272 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
3273 {
3274 	struct clk_core *child;
3275 
3276 	clk_dump_one(s, c, level);
3277 
3278 	hlist_for_each_entry(child, &c->children, child_node) {
3279 		seq_putc(s, ',');
3280 		clk_dump_subtree(s, child, level + 1);
3281 	}
3282 
3283 	seq_putc(s, '}');
3284 }
3285 
clk_dump_show(struct seq_file * s,void * data)3286 static int clk_dump_show(struct seq_file *s, void *data)
3287 {
3288 	struct clk_core *c;
3289 	bool first_node = true;
3290 	struct hlist_head **lists = s->private;
3291 
3292 	seq_putc(s, '{');
3293 	clk_prepare_lock();
3294 
3295 	for (; *lists; lists++) {
3296 		hlist_for_each_entry(c, *lists, child_node) {
3297 			if (!first_node)
3298 				seq_putc(s, ',');
3299 			first_node = false;
3300 			clk_dump_subtree(s, c, 0);
3301 		}
3302 	}
3303 
3304 	clk_prepare_unlock();
3305 
3306 	seq_puts(s, "}\n");
3307 	return 0;
3308 }
3309 DEFINE_SHOW_ATTRIBUTE(clk_dump);
3310 
3311 #undef CLOCK_ALLOW_WRITE_DEBUGFS
3312 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3313 /*
3314  * This can be dangerous, therefore don't provide any real compile time
3315  * configuration option for this feature.
3316  * People who want to use this will need to modify the source code directly.
3317  */
clk_rate_set(void * data,u64 val)3318 static int clk_rate_set(void *data, u64 val)
3319 {
3320 	struct clk_core *core = data;
3321 	int ret;
3322 
3323 	clk_prepare_lock();
3324 	ret = clk_core_set_rate_nolock(core, val);
3325 	clk_prepare_unlock();
3326 
3327 	return ret;
3328 }
3329 
3330 #define clk_rate_mode	0644
3331 
clk_prepare_enable_set(void * data,u64 val)3332 static int clk_prepare_enable_set(void *data, u64 val)
3333 {
3334 	struct clk_core *core = data;
3335 	int ret = 0;
3336 
3337 	if (val)
3338 		ret = clk_prepare_enable(core->hw->clk);
3339 	else
3340 		clk_disable_unprepare(core->hw->clk);
3341 
3342 	return ret;
3343 }
3344 
clk_prepare_enable_get(void * data,u64 * val)3345 static int clk_prepare_enable_get(void *data, u64 *val)
3346 {
3347 	struct clk_core *core = data;
3348 
3349 	*val = core->enable_count && core->prepare_count;
3350 	return 0;
3351 }
3352 
3353 DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
3354 			 clk_prepare_enable_set, "%llu\n");
3355 
3356 #else
3357 #define clk_rate_set	NULL
3358 #define clk_rate_mode	0444
3359 #endif
3360 
clk_rate_get(void * data,u64 * val)3361 static int clk_rate_get(void *data, u64 *val)
3362 {
3363 	struct clk_core *core = data;
3364 
3365 	clk_prepare_lock();
3366 	*val = clk_core_get_rate_recalc(core);
3367 	clk_prepare_unlock();
3368 
3369 	return 0;
3370 }
3371 
3372 DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3373 
3374 static const struct {
3375 	unsigned long flag;
3376 	const char *name;
3377 } clk_flags[] = {
3378 #define ENTRY(f) { f, #f }
3379 	ENTRY(CLK_SET_RATE_GATE),
3380 	ENTRY(CLK_SET_PARENT_GATE),
3381 	ENTRY(CLK_SET_RATE_PARENT),
3382 	ENTRY(CLK_IGNORE_UNUSED),
3383 	ENTRY(CLK_GET_RATE_NOCACHE),
3384 	ENTRY(CLK_SET_RATE_NO_REPARENT),
3385 	ENTRY(CLK_GET_ACCURACY_NOCACHE),
3386 	ENTRY(CLK_RECALC_NEW_RATES),
3387 	ENTRY(CLK_SET_RATE_UNGATE),
3388 	ENTRY(CLK_IS_CRITICAL),
3389 	ENTRY(CLK_OPS_PARENT_ENABLE),
3390 	ENTRY(CLK_DUTY_CYCLE_PARENT),
3391 #undef ENTRY
3392 };
3393 
clk_flags_show(struct seq_file * s,void * data)3394 static int clk_flags_show(struct seq_file *s, void *data)
3395 {
3396 	struct clk_core *core = s->private;
3397 	unsigned long flags = core->flags;
3398 	unsigned int i;
3399 
3400 	for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3401 		if (flags & clk_flags[i].flag) {
3402 			seq_printf(s, "%s\n", clk_flags[i].name);
3403 			flags &= ~clk_flags[i].flag;
3404 		}
3405 	}
3406 	if (flags) {
3407 		/* Unknown flags */
3408 		seq_printf(s, "0x%lx\n", flags);
3409 	}
3410 
3411 	return 0;
3412 }
3413 DEFINE_SHOW_ATTRIBUTE(clk_flags);
3414 
possible_parent_show(struct seq_file * s,struct clk_core * core,unsigned int i,char terminator)3415 static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3416 				 unsigned int i, char terminator)
3417 {
3418 	struct clk_core *parent;
3419 	const char *name = NULL;
3420 
3421 	/*
3422 	 * Go through the following options to fetch a parent's name.
3423 	 *
3424 	 * 1. Fetch the registered parent clock and use its name
3425 	 * 2. Use the global (fallback) name if specified
3426 	 * 3. Use the local fw_name if provided
3427 	 * 4. Fetch parent clock's clock-output-name if DT index was set
3428 	 *
3429 	 * This may still fail in some cases, such as when the parent is
3430 	 * specified directly via a struct clk_hw pointer, but it isn't
3431 	 * registered (yet).
3432 	 */
3433 	parent = clk_core_get_parent_by_index(core, i);
3434 	if (parent) {
3435 		seq_puts(s, parent->name);
3436 	} else if (core->parents[i].name) {
3437 		seq_puts(s, core->parents[i].name);
3438 	} else if (core->parents[i].fw_name) {
3439 		seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3440 	} else {
3441 		if (core->parents[i].index >= 0)
3442 			name = of_clk_get_parent_name(core->of_node, core->parents[i].index);
3443 		if (!name)
3444 			name = "(missing)";
3445 
3446 		seq_puts(s, name);
3447 	}
3448 
3449 	seq_putc(s, terminator);
3450 }
3451 
possible_parents_show(struct seq_file * s,void * data)3452 static int possible_parents_show(struct seq_file *s, void *data)
3453 {
3454 	struct clk_core *core = s->private;
3455 	int i;
3456 
3457 	for (i = 0; i < core->num_parents - 1; i++)
3458 		possible_parent_show(s, core, i, ' ');
3459 
3460 	possible_parent_show(s, core, i, '\n');
3461 
3462 	return 0;
3463 }
3464 DEFINE_SHOW_ATTRIBUTE(possible_parents);
3465 
current_parent_show(struct seq_file * s,void * data)3466 static int current_parent_show(struct seq_file *s, void *data)
3467 {
3468 	struct clk_core *core = s->private;
3469 
3470 	if (core->parent)
3471 		seq_printf(s, "%s\n", core->parent->name);
3472 
3473 	return 0;
3474 }
3475 DEFINE_SHOW_ATTRIBUTE(current_parent);
3476 
3477 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
current_parent_write(struct file * file,const char __user * ubuf,size_t count,loff_t * ppos)3478 static ssize_t current_parent_write(struct file *file, const char __user *ubuf,
3479 				    size_t count, loff_t *ppos)
3480 {
3481 	struct seq_file *s = file->private_data;
3482 	struct clk_core *core = s->private;
3483 	struct clk_core *parent;
3484 	u8 idx;
3485 	int err;
3486 
3487 	err = kstrtou8_from_user(ubuf, count, 0, &idx);
3488 	if (err < 0)
3489 		return err;
3490 
3491 	parent = clk_core_get_parent_by_index(core, idx);
3492 	if (!parent)
3493 		return -ENOENT;
3494 
3495 	clk_prepare_lock();
3496 	err = clk_core_set_parent_nolock(core, parent);
3497 	clk_prepare_unlock();
3498 	if (err)
3499 		return err;
3500 
3501 	return count;
3502 }
3503 
3504 static const struct file_operations current_parent_rw_fops = {
3505 	.open		= current_parent_open,
3506 	.write		= current_parent_write,
3507 	.read		= seq_read,
3508 	.llseek		= seq_lseek,
3509 	.release	= single_release,
3510 };
3511 #endif
3512 
clk_duty_cycle_show(struct seq_file * s,void * data)3513 static int clk_duty_cycle_show(struct seq_file *s, void *data)
3514 {
3515 	struct clk_core *core = s->private;
3516 	struct clk_duty *duty = &core->duty;
3517 
3518 	seq_printf(s, "%u/%u\n", duty->num, duty->den);
3519 
3520 	return 0;
3521 }
3522 DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3523 
clk_min_rate_show(struct seq_file * s,void * data)3524 static int clk_min_rate_show(struct seq_file *s, void *data)
3525 {
3526 	struct clk_core *core = s->private;
3527 	unsigned long min_rate, max_rate;
3528 
3529 	clk_prepare_lock();
3530 	clk_core_get_boundaries(core, &min_rate, &max_rate);
3531 	clk_prepare_unlock();
3532 	seq_printf(s, "%lu\n", min_rate);
3533 
3534 	return 0;
3535 }
3536 DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3537 
clk_max_rate_show(struct seq_file * s,void * data)3538 static int clk_max_rate_show(struct seq_file *s, void *data)
3539 {
3540 	struct clk_core *core = s->private;
3541 	unsigned long min_rate, max_rate;
3542 
3543 	clk_prepare_lock();
3544 	clk_core_get_boundaries(core, &min_rate, &max_rate);
3545 	clk_prepare_unlock();
3546 	seq_printf(s, "%lu\n", max_rate);
3547 
3548 	return 0;
3549 }
3550 DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3551 
clk_debug_create_one(struct clk_core * core,struct dentry * pdentry)3552 static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3553 {
3554 	struct dentry *root;
3555 
3556 	if (!core || !pdentry)
3557 		return;
3558 
3559 	root = debugfs_create_dir(core->name, pdentry);
3560 	core->dentry = root;
3561 
3562 	debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3563 			    &clk_rate_fops);
3564 	debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3565 	debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3566 	debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3567 	debugfs_create_u32("clk_phase", 0444, root, &core->phase);
3568 	debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3569 	debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3570 	debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3571 	debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3572 	debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3573 	debugfs_create_file("clk_duty_cycle", 0444, root, core,
3574 			    &clk_duty_cycle_fops);
3575 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3576 	debugfs_create_file("clk_prepare_enable", 0644, root, core,
3577 			    &clk_prepare_enable_fops);
3578 
3579 	if (core->num_parents > 1)
3580 		debugfs_create_file("clk_parent", 0644, root, core,
3581 				    &current_parent_rw_fops);
3582 	else
3583 #endif
3584 	if (core->num_parents > 0)
3585 		debugfs_create_file("clk_parent", 0444, root, core,
3586 				    &current_parent_fops);
3587 
3588 	if (core->num_parents > 1)
3589 		debugfs_create_file("clk_possible_parents", 0444, root, core,
3590 				    &possible_parents_fops);
3591 
3592 	if (core->ops->debug_init)
3593 		core->ops->debug_init(core->hw, core->dentry);
3594 }
3595 
3596 /**
3597  * clk_debug_register - add a clk node to the debugfs clk directory
3598  * @core: the clk being added to the debugfs clk directory
3599  *
3600  * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3601  * initialized.  Otherwise it bails out early since the debugfs clk directory
3602  * will be created lazily by clk_debug_init as part of a late_initcall.
3603  */
clk_debug_register(struct clk_core * core)3604 static void clk_debug_register(struct clk_core *core)
3605 {
3606 	mutex_lock(&clk_debug_lock);
3607 	hlist_add_head(&core->debug_node, &clk_debug_list);
3608 	if (inited)
3609 		clk_debug_create_one(core, rootdir);
3610 	mutex_unlock(&clk_debug_lock);
3611 }
3612 
3613  /**
3614  * clk_debug_unregister - remove a clk node from the debugfs clk directory
3615  * @core: the clk being removed from the debugfs clk directory
3616  *
3617  * Dynamically removes a clk and all its child nodes from the
3618  * debugfs clk directory if clk->dentry points to debugfs created by
3619  * clk_debug_register in __clk_core_init.
3620  */
clk_debug_unregister(struct clk_core * core)3621 static void clk_debug_unregister(struct clk_core *core)
3622 {
3623 	mutex_lock(&clk_debug_lock);
3624 	hlist_del_init(&core->debug_node);
3625 	debugfs_remove_recursive(core->dentry);
3626 	core->dentry = NULL;
3627 	mutex_unlock(&clk_debug_lock);
3628 }
3629 
3630 /**
3631  * clk_debug_init - lazily populate the debugfs clk directory
3632  *
3633  * clks are often initialized very early during boot before memory can be
3634  * dynamically allocated and well before debugfs is setup. This function
3635  * populates the debugfs clk directory once at boot-time when we know that
3636  * debugfs is setup. It should only be called once at boot-time, all other clks
3637  * added dynamically will be done so with clk_debug_register.
3638  */
clk_debug_init(void)3639 static int __init clk_debug_init(void)
3640 {
3641 	struct clk_core *core;
3642 
3643 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3644 	pr_warn("\n");
3645 	pr_warn("********************************************************************\n");
3646 	pr_warn("**     NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE           **\n");
3647 	pr_warn("**                                                                **\n");
3648 	pr_warn("**  WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
3649 	pr_warn("**                                                                **\n");
3650 	pr_warn("** This means that this kernel is built to expose clk operations  **\n");
3651 	pr_warn("** such as parent or rate setting, enabling, disabling, etc.      **\n");
3652 	pr_warn("** to userspace, which may compromise security on your system.    **\n");
3653 	pr_warn("**                                                                **\n");
3654 	pr_warn("** If you see this message and you are not debugging the          **\n");
3655 	pr_warn("** kernel, report this immediately to your vendor!                **\n");
3656 	pr_warn("**                                                                **\n");
3657 	pr_warn("**     NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE           **\n");
3658 	pr_warn("********************************************************************\n");
3659 #endif
3660 
3661 	rootdir = debugfs_create_dir("clk", NULL);
3662 
3663 	debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3664 			    &clk_summary_fops);
3665 	debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3666 			    &clk_dump_fops);
3667 	debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3668 			    &clk_summary_fops);
3669 	debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3670 			    &clk_dump_fops);
3671 
3672 	mutex_lock(&clk_debug_lock);
3673 	hlist_for_each_entry(core, &clk_debug_list, debug_node)
3674 		clk_debug_create_one(core, rootdir);
3675 
3676 	inited = 1;
3677 	mutex_unlock(&clk_debug_lock);
3678 
3679 	return 0;
3680 }
3681 late_initcall(clk_debug_init);
3682 #else
clk_debug_register(struct clk_core * core)3683 static inline void clk_debug_register(struct clk_core *core) { }
clk_debug_unregister(struct clk_core * core)3684 static inline void clk_debug_unregister(struct clk_core *core)
3685 {
3686 }
3687 #endif
3688 
clk_core_reparent_orphans_nolock(void)3689 static void clk_core_reparent_orphans_nolock(void)
3690 {
3691 	struct clk_core *orphan;
3692 	struct hlist_node *tmp2;
3693 
3694 	/*
3695 	 * walk the list of orphan clocks and reparent any that newly finds a
3696 	 * parent.
3697 	 */
3698 	hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3699 		struct clk_core *parent = __clk_init_parent(orphan);
3700 
3701 		/*
3702 		 * We need to use __clk_set_parent_before() and _after() to
3703 		 * properly migrate any prepare/enable count of the orphan
3704 		 * clock. This is important for CLK_IS_CRITICAL clocks, which
3705 		 * are enabled during init but might not have a parent yet.
3706 		 */
3707 		if (parent) {
3708 			/* update the clk tree topology */
3709 			__clk_set_parent_before(orphan, parent);
3710 			__clk_set_parent_after(orphan, parent, NULL);
3711 			__clk_recalc_accuracies(orphan);
3712 			__clk_recalc_rates(orphan, true, 0);
3713 
3714 			/*
3715 			 * __clk_init_parent() will set the initial req_rate to
3716 			 * 0 if the clock doesn't have clk_ops::recalc_rate and
3717 			 * is an orphan when it's registered.
3718 			 *
3719 			 * 'req_rate' is used by clk_set_rate_range() and
3720 			 * clk_put() to trigger a clk_set_rate() call whenever
3721 			 * the boundaries are modified. Let's make sure
3722 			 * 'req_rate' is set to something non-zero so that
3723 			 * clk_set_rate_range() doesn't drop the frequency.
3724 			 */
3725 			orphan->req_rate = orphan->rate;
3726 		}
3727 	}
3728 }
3729 
3730 /**
3731  * __clk_core_init - initialize the data structures in a struct clk_core
3732  * @core:	clk_core being initialized
3733  *
3734  * Initializes the lists in struct clk_core, queries the hardware for the
3735  * parent and rate and sets them both.
3736  */
__clk_core_init(struct clk_core * core)3737 static int __clk_core_init(struct clk_core *core)
3738 {
3739 	int ret;
3740 	struct clk_core *parent;
3741 	unsigned long rate;
3742 	int phase;
3743 
3744 	clk_prepare_lock();
3745 
3746 	/*
3747 	 * Set hw->core after grabbing the prepare_lock to synchronize with
3748 	 * callers of clk_core_fill_parent_index() where we treat hw->core
3749 	 * being NULL as the clk not being registered yet. This is crucial so
3750 	 * that clks aren't parented until their parent is fully registered.
3751 	 */
3752 	core->hw->core = core;
3753 
3754 	ret = clk_pm_runtime_get(core);
3755 	if (ret)
3756 		goto unlock;
3757 
3758 	/* check to see if a clock with this name is already registered */
3759 	if (clk_core_lookup(core->name)) {
3760 		pr_debug("%s: clk %s already initialized\n",
3761 				__func__, core->name);
3762 		ret = -EEXIST;
3763 		goto out;
3764 	}
3765 
3766 	/* check that clk_ops are sane.  See Documentation/driver-api/clk.rst */
3767 	if (core->ops->set_rate &&
3768 	    !((core->ops->round_rate || core->ops->determine_rate) &&
3769 	      core->ops->recalc_rate)) {
3770 		pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3771 		       __func__, core->name);
3772 		ret = -EINVAL;
3773 		goto out;
3774 	}
3775 
3776 	if (core->ops->set_parent && !core->ops->get_parent) {
3777 		pr_err("%s: %s must implement .get_parent & .set_parent\n",
3778 		       __func__, core->name);
3779 		ret = -EINVAL;
3780 		goto out;
3781 	}
3782 
3783 	if (core->ops->set_parent && !core->ops->determine_rate) {
3784 		pr_err("%s: %s must implement .set_parent & .determine_rate\n",
3785 			__func__, core->name);
3786 		ret = -EINVAL;
3787 		goto out;
3788 	}
3789 
3790 	if (core->num_parents > 1 && !core->ops->get_parent) {
3791 		pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3792 		       __func__, core->name);
3793 		ret = -EINVAL;
3794 		goto out;
3795 	}
3796 
3797 	if (core->ops->set_rate_and_parent &&
3798 			!(core->ops->set_parent && core->ops->set_rate)) {
3799 		pr_err("%s: %s must implement .set_parent & .set_rate\n",
3800 				__func__, core->name);
3801 		ret = -EINVAL;
3802 		goto out;
3803 	}
3804 
3805 	/*
3806 	 * optional platform-specific magic
3807 	 *
3808 	 * The .init callback is not used by any of the basic clock types, but
3809 	 * exists for weird hardware that must perform initialization magic for
3810 	 * CCF to get an accurate view of clock for any other callbacks. It may
3811 	 * also be used needs to perform dynamic allocations. Such allocation
3812 	 * must be freed in the terminate() callback.
3813 	 * This callback shall not be used to initialize the parameters state,
3814 	 * such as rate, parent, etc ...
3815 	 *
3816 	 * If it exist, this callback should called before any other callback of
3817 	 * the clock
3818 	 */
3819 	if (core->ops->init) {
3820 		ret = core->ops->init(core->hw);
3821 		if (ret)
3822 			goto out;
3823 	}
3824 
3825 	parent = core->parent = __clk_init_parent(core);
3826 
3827 	/*
3828 	 * Populate core->parent if parent has already been clk_core_init'd. If
3829 	 * parent has not yet been clk_core_init'd then place clk in the orphan
3830 	 * list.  If clk doesn't have any parents then place it in the root
3831 	 * clk list.
3832 	 *
3833 	 * Every time a new clk is clk_init'd then we walk the list of orphan
3834 	 * clocks and re-parent any that are children of the clock currently
3835 	 * being clk_init'd.
3836 	 */
3837 	if (parent) {
3838 		hlist_add_head(&core->child_node, &parent->children);
3839 		core->orphan = parent->orphan;
3840 	} else if (!core->num_parents) {
3841 		hlist_add_head(&core->child_node, &clk_root_list);
3842 		core->orphan = false;
3843 	} else {
3844 		hlist_add_head(&core->child_node, &clk_orphan_list);
3845 		core->orphan = true;
3846 	}
3847 
3848 	/*
3849 	 * Set clk's accuracy.  The preferred method is to use
3850 	 * .recalc_accuracy. For simple clocks and lazy developers the default
3851 	 * fallback is to use the parent's accuracy.  If a clock doesn't have a
3852 	 * parent (or is orphaned) then accuracy is set to zero (perfect
3853 	 * clock).
3854 	 */
3855 	if (core->ops->recalc_accuracy)
3856 		core->accuracy = core->ops->recalc_accuracy(core->hw,
3857 					clk_core_get_accuracy_no_lock(parent));
3858 	else if (parent)
3859 		core->accuracy = parent->accuracy;
3860 	else
3861 		core->accuracy = 0;
3862 
3863 	/*
3864 	 * Set clk's phase by clk_core_get_phase() caching the phase.
3865 	 * Since a phase is by definition relative to its parent, just
3866 	 * query the current clock phase, or just assume it's in phase.
3867 	 */
3868 	phase = clk_core_get_phase(core);
3869 	if (phase < 0) {
3870 		ret = phase;
3871 		pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
3872 			core->name);
3873 		goto out;
3874 	}
3875 
3876 	/*
3877 	 * Set clk's duty cycle.
3878 	 */
3879 	clk_core_update_duty_cycle_nolock(core);
3880 
3881 	/*
3882 	 * Set clk's rate.  The preferred method is to use .recalc_rate.  For
3883 	 * simple clocks and lazy developers the default fallback is to use the
3884 	 * parent's rate.  If a clock doesn't have a parent (or is orphaned)
3885 	 * then rate is set to zero.
3886 	 */
3887 	if (core->ops->recalc_rate)
3888 		rate = core->ops->recalc_rate(core->hw,
3889 				clk_core_get_rate_nolock(parent));
3890 	else if (parent)
3891 		rate = parent->rate;
3892 	else
3893 		rate = 0;
3894 	core->rate = core->req_rate = rate;
3895 
3896 	/*
3897 	 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3898 	 * don't get accidentally disabled when walking the orphan tree and
3899 	 * reparenting clocks
3900 	 */
3901 	if (core->flags & CLK_IS_CRITICAL) {
3902 		ret = clk_core_prepare(core);
3903 		if (ret) {
3904 			pr_warn("%s: critical clk '%s' failed to prepare\n",
3905 			       __func__, core->name);
3906 			goto out;
3907 		}
3908 
3909 		ret = clk_core_enable_lock(core);
3910 		if (ret) {
3911 			pr_warn("%s: critical clk '%s' failed to enable\n",
3912 			       __func__, core->name);
3913 			clk_core_unprepare(core);
3914 			goto out;
3915 		}
3916 	}
3917 
3918 	clk_core_reparent_orphans_nolock();
3919 
3920 	kref_init(&core->ref);
3921 out:
3922 	clk_pm_runtime_put(core);
3923 unlock:
3924 	if (ret) {
3925 		hlist_del_init(&core->child_node);
3926 		core->hw->core = NULL;
3927 	}
3928 
3929 	clk_prepare_unlock();
3930 
3931 	if (!ret)
3932 		clk_debug_register(core);
3933 
3934 	return ret;
3935 }
3936 
3937 /**
3938  * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
3939  * @core: clk to add consumer to
3940  * @clk: consumer to link to a clk
3941  */
clk_core_link_consumer(struct clk_core * core,struct clk * clk)3942 static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
3943 {
3944 	clk_prepare_lock();
3945 	hlist_add_head(&clk->clks_node, &core->clks);
3946 	clk_prepare_unlock();
3947 }
3948 
3949 /**
3950  * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
3951  * @clk: consumer to unlink
3952  */
clk_core_unlink_consumer(struct clk * clk)3953 static void clk_core_unlink_consumer(struct clk *clk)
3954 {
3955 	lockdep_assert_held(&prepare_lock);
3956 	hlist_del(&clk->clks_node);
3957 }
3958 
3959 /**
3960  * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
3961  * @core: clk to allocate a consumer for
3962  * @dev_id: string describing device name
3963  * @con_id: connection ID string on device
3964  *
3965  * Returns: clk consumer left unlinked from the consumer list
3966  */
alloc_clk(struct clk_core * core,const char * dev_id,const char * con_id)3967 static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
3968 			     const char *con_id)
3969 {
3970 	struct clk *clk;
3971 
3972 	clk = kzalloc(sizeof(*clk), GFP_KERNEL);
3973 	if (!clk)
3974 		return ERR_PTR(-ENOMEM);
3975 
3976 	clk->core = core;
3977 	clk->dev_id = dev_id;
3978 	clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
3979 	clk->max_rate = ULONG_MAX;
3980 
3981 	return clk;
3982 }
3983 
3984 /**
3985  * free_clk - Free a clk consumer
3986  * @clk: clk consumer to free
3987  *
3988  * Note, this assumes the clk has been unlinked from the clk_core consumer
3989  * list.
3990  */
free_clk(struct clk * clk)3991 static void free_clk(struct clk *clk)
3992 {
3993 	kfree_const(clk->con_id);
3994 	kfree(clk);
3995 }
3996 
3997 /**
3998  * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
3999  * a clk_hw
4000  * @dev: clk consumer device
4001  * @hw: clk_hw associated with the clk being consumed
4002  * @dev_id: string describing device name
4003  * @con_id: connection ID string on device
4004  *
4005  * This is the main function used to create a clk pointer for use by clk
4006  * consumers. It connects a consumer to the clk_core and clk_hw structures
4007  * used by the framework and clk provider respectively.
4008  */
clk_hw_create_clk(struct device * dev,struct clk_hw * hw,const char * dev_id,const char * con_id)4009 struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
4010 			      const char *dev_id, const char *con_id)
4011 {
4012 	struct clk *clk;
4013 	struct clk_core *core;
4014 
4015 	/* This is to allow this function to be chained to others */
4016 	if (IS_ERR_OR_NULL(hw))
4017 		return ERR_CAST(hw);
4018 
4019 	core = hw->core;
4020 	clk = alloc_clk(core, dev_id, con_id);
4021 	if (IS_ERR(clk))
4022 		return clk;
4023 	clk->dev = dev;
4024 
4025 	if (!try_module_get(core->owner)) {
4026 		free_clk(clk);
4027 		return ERR_PTR(-ENOENT);
4028 	}
4029 
4030 	kref_get(&core->ref);
4031 	clk_core_link_consumer(core, clk);
4032 
4033 	return clk;
4034 }
4035 
4036 /**
4037  * clk_hw_get_clk - get clk consumer given an clk_hw
4038  * @hw: clk_hw associated with the clk being consumed
4039  * @con_id: connection ID string on device
4040  *
4041  * Returns: new clk consumer
4042  * This is the function to be used by providers which need
4043  * to get a consumer clk and act on the clock element
4044  * Calls to this function must be balanced with calls clk_put()
4045  */
clk_hw_get_clk(struct clk_hw * hw,const char * con_id)4046 struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
4047 {
4048 	struct device *dev = hw->core->dev;
4049 	const char *name = dev ? dev_name(dev) : NULL;
4050 
4051 	return clk_hw_create_clk(dev, hw, name, con_id);
4052 }
4053 EXPORT_SYMBOL(clk_hw_get_clk);
4054 
clk_cpy_name(const char ** dst_p,const char * src,bool must_exist)4055 static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
4056 {
4057 	const char *dst;
4058 
4059 	if (!src) {
4060 		if (must_exist)
4061 			return -EINVAL;
4062 		return 0;
4063 	}
4064 
4065 	*dst_p = dst = kstrdup_const(src, GFP_KERNEL);
4066 	if (!dst)
4067 		return -ENOMEM;
4068 
4069 	return 0;
4070 }
4071 
clk_core_populate_parent_map(struct clk_core * core,const struct clk_init_data * init)4072 static int clk_core_populate_parent_map(struct clk_core *core,
4073 					const struct clk_init_data *init)
4074 {
4075 	u8 num_parents = init->num_parents;
4076 	const char * const *parent_names = init->parent_names;
4077 	const struct clk_hw **parent_hws = init->parent_hws;
4078 	const struct clk_parent_data *parent_data = init->parent_data;
4079 	int i, ret = 0;
4080 	struct clk_parent_map *parents, *parent;
4081 
4082 	if (!num_parents)
4083 		return 0;
4084 
4085 	/*
4086 	 * Avoid unnecessary string look-ups of clk_core's possible parents by
4087 	 * having a cache of names/clk_hw pointers to clk_core pointers.
4088 	 */
4089 	parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
4090 	core->parents = parents;
4091 	if (!parents)
4092 		return -ENOMEM;
4093 
4094 	/* Copy everything over because it might be __initdata */
4095 	for (i = 0, parent = parents; i < num_parents; i++, parent++) {
4096 		parent->index = -1;
4097 		if (parent_names) {
4098 			/* throw a WARN if any entries are NULL */
4099 			WARN(!parent_names[i],
4100 				"%s: invalid NULL in %s's .parent_names\n",
4101 				__func__, core->name);
4102 			ret = clk_cpy_name(&parent->name, parent_names[i],
4103 					   true);
4104 		} else if (parent_data) {
4105 			parent->hw = parent_data[i].hw;
4106 			parent->index = parent_data[i].index;
4107 			ret = clk_cpy_name(&parent->fw_name,
4108 					   parent_data[i].fw_name, false);
4109 			if (!ret)
4110 				ret = clk_cpy_name(&parent->name,
4111 						   parent_data[i].name,
4112 						   false);
4113 		} else if (parent_hws) {
4114 			parent->hw = parent_hws[i];
4115 		} else {
4116 			ret = -EINVAL;
4117 			WARN(1, "Must specify parents if num_parents > 0\n");
4118 		}
4119 
4120 		if (ret) {
4121 			do {
4122 				kfree_const(parents[i].name);
4123 				kfree_const(parents[i].fw_name);
4124 			} while (--i >= 0);
4125 			kfree(parents);
4126 
4127 			return ret;
4128 		}
4129 	}
4130 
4131 	return 0;
4132 }
4133 
clk_core_free_parent_map(struct clk_core * core)4134 static void clk_core_free_parent_map(struct clk_core *core)
4135 {
4136 	int i = core->num_parents;
4137 
4138 	if (!core->num_parents)
4139 		return;
4140 
4141 	while (--i >= 0) {
4142 		kfree_const(core->parents[i].name);
4143 		kfree_const(core->parents[i].fw_name);
4144 	}
4145 
4146 	kfree(core->parents);
4147 }
4148 
4149 static struct clk *
__clk_register(struct device * dev,struct device_node * np,struct clk_hw * hw)4150 __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
4151 {
4152 	int ret;
4153 	struct clk_core *core;
4154 	const struct clk_init_data *init = hw->init;
4155 
4156 	/*
4157 	 * The init data is not supposed to be used outside of registration path.
4158 	 * Set it to NULL so that provider drivers can't use it either and so that
4159 	 * we catch use of hw->init early on in the core.
4160 	 */
4161 	hw->init = NULL;
4162 
4163 	core = kzalloc(sizeof(*core), GFP_KERNEL);
4164 	if (!core) {
4165 		ret = -ENOMEM;
4166 		goto fail_out;
4167 	}
4168 
4169 	core->name = kstrdup_const(init->name, GFP_KERNEL);
4170 	if (!core->name) {
4171 		ret = -ENOMEM;
4172 		goto fail_name;
4173 	}
4174 
4175 	if (WARN_ON(!init->ops)) {
4176 		ret = -EINVAL;
4177 		goto fail_ops;
4178 	}
4179 	core->ops = init->ops;
4180 
4181 	if (dev && pm_runtime_enabled(dev))
4182 		core->rpm_enabled = true;
4183 	core->dev = dev;
4184 	core->of_node = np;
4185 	if (dev && dev->driver)
4186 		core->owner = dev->driver->owner;
4187 	core->hw = hw;
4188 	core->flags = init->flags;
4189 	core->num_parents = init->num_parents;
4190 	core->min_rate = 0;
4191 	core->max_rate = ULONG_MAX;
4192 
4193 	ret = clk_core_populate_parent_map(core, init);
4194 	if (ret)
4195 		goto fail_parents;
4196 
4197 	INIT_HLIST_HEAD(&core->clks);
4198 
4199 	/*
4200 	 * Don't call clk_hw_create_clk() here because that would pin the
4201 	 * provider module to itself and prevent it from ever being removed.
4202 	 */
4203 	hw->clk = alloc_clk(core, NULL, NULL);
4204 	if (IS_ERR(hw->clk)) {
4205 		ret = PTR_ERR(hw->clk);
4206 		goto fail_create_clk;
4207 	}
4208 
4209 	clk_core_link_consumer(core, hw->clk);
4210 
4211 	ret = __clk_core_init(core);
4212 	if (!ret)
4213 		return hw->clk;
4214 
4215 	clk_prepare_lock();
4216 	clk_core_unlink_consumer(hw->clk);
4217 	clk_prepare_unlock();
4218 
4219 	free_clk(hw->clk);
4220 	hw->clk = NULL;
4221 
4222 fail_create_clk:
4223 	clk_core_free_parent_map(core);
4224 fail_parents:
4225 fail_ops:
4226 	kfree_const(core->name);
4227 fail_name:
4228 	kfree(core);
4229 fail_out:
4230 	return ERR_PTR(ret);
4231 }
4232 
4233 /**
4234  * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
4235  * @dev: Device to get device node of
4236  *
4237  * Return: device node pointer of @dev, or the device node pointer of
4238  * @dev->parent if dev doesn't have a device node, or NULL if neither
4239  * @dev or @dev->parent have a device node.
4240  */
dev_or_parent_of_node(struct device * dev)4241 static struct device_node *dev_or_parent_of_node(struct device *dev)
4242 {
4243 	struct device_node *np;
4244 
4245 	if (!dev)
4246 		return NULL;
4247 
4248 	np = dev_of_node(dev);
4249 	if (!np)
4250 		np = dev_of_node(dev->parent);
4251 
4252 	return np;
4253 }
4254 
4255 /**
4256  * clk_register - allocate a new clock, register it and return an opaque cookie
4257  * @dev: device that is registering this clock
4258  * @hw: link to hardware-specific clock data
4259  *
4260  * clk_register is the *deprecated* interface for populating the clock tree with
4261  * new clock nodes. Use clk_hw_register() instead.
4262  *
4263  * Returns: a pointer to the newly allocated struct clk which
4264  * cannot be dereferenced by driver code but may be used in conjunction with the
4265  * rest of the clock API.  In the event of an error clk_register will return an
4266  * error code; drivers must test for an error code after calling clk_register.
4267  */
clk_register(struct device * dev,struct clk_hw * hw)4268 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
4269 {
4270 	return __clk_register(dev, dev_or_parent_of_node(dev), hw);
4271 }
4272 EXPORT_SYMBOL_GPL(clk_register);
4273 
4274 /**
4275  * clk_hw_register - register a clk_hw and return an error code
4276  * @dev: device that is registering this clock
4277  * @hw: link to hardware-specific clock data
4278  *
4279  * clk_hw_register is the primary interface for populating the clock tree with
4280  * new clock nodes. It returns an integer equal to zero indicating success or
4281  * less than zero indicating failure. Drivers must test for an error code after
4282  * calling clk_hw_register().
4283  */
clk_hw_register(struct device * dev,struct clk_hw * hw)4284 int clk_hw_register(struct device *dev, struct clk_hw *hw)
4285 {
4286 	return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
4287 			       hw));
4288 }
4289 EXPORT_SYMBOL_GPL(clk_hw_register);
4290 
4291 /*
4292  * of_clk_hw_register - register a clk_hw and return an error code
4293  * @node: device_node of device that is registering this clock
4294  * @hw: link to hardware-specific clock data
4295  *
4296  * of_clk_hw_register() is the primary interface for populating the clock tree
4297  * with new clock nodes when a struct device is not available, but a struct
4298  * device_node is. It returns an integer equal to zero indicating success or
4299  * less than zero indicating failure. Drivers must test for an error code after
4300  * calling of_clk_hw_register().
4301  */
of_clk_hw_register(struct device_node * node,struct clk_hw * hw)4302 int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
4303 {
4304 	return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
4305 }
4306 EXPORT_SYMBOL_GPL(of_clk_hw_register);
4307 
4308 /* Free memory allocated for a clock. */
__clk_release(struct kref * ref)4309 static void __clk_release(struct kref *ref)
4310 {
4311 	struct clk_core *core = container_of(ref, struct clk_core, ref);
4312 
4313 	lockdep_assert_held(&prepare_lock);
4314 
4315 	clk_core_free_parent_map(core);
4316 	kfree_const(core->name);
4317 	kfree(core);
4318 }
4319 
4320 /*
4321  * Empty clk_ops for unregistered clocks. These are used temporarily
4322  * after clk_unregister() was called on a clock and until last clock
4323  * consumer calls clk_put() and the struct clk object is freed.
4324  */
clk_nodrv_prepare_enable(struct clk_hw * hw)4325 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
4326 {
4327 	return -ENXIO;
4328 }
4329 
clk_nodrv_disable_unprepare(struct clk_hw * hw)4330 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
4331 {
4332 	WARN_ON_ONCE(1);
4333 }
4334 
clk_nodrv_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)4335 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
4336 					unsigned long parent_rate)
4337 {
4338 	return -ENXIO;
4339 }
4340 
clk_nodrv_set_parent(struct clk_hw * hw,u8 index)4341 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
4342 {
4343 	return -ENXIO;
4344 }
4345 
clk_nodrv_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)4346 static int clk_nodrv_determine_rate(struct clk_hw *hw,
4347 				    struct clk_rate_request *req)
4348 {
4349 	return -ENXIO;
4350 }
4351 
4352 static const struct clk_ops clk_nodrv_ops = {
4353 	.enable		= clk_nodrv_prepare_enable,
4354 	.disable	= clk_nodrv_disable_unprepare,
4355 	.prepare	= clk_nodrv_prepare_enable,
4356 	.unprepare	= clk_nodrv_disable_unprepare,
4357 	.determine_rate	= clk_nodrv_determine_rate,
4358 	.set_rate	= clk_nodrv_set_rate,
4359 	.set_parent	= clk_nodrv_set_parent,
4360 };
4361 
clk_core_evict_parent_cache_subtree(struct clk_core * root,const struct clk_core * target)4362 static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
4363 						const struct clk_core *target)
4364 {
4365 	int i;
4366 	struct clk_core *child;
4367 
4368 	for (i = 0; i < root->num_parents; i++)
4369 		if (root->parents[i].core == target)
4370 			root->parents[i].core = NULL;
4371 
4372 	hlist_for_each_entry(child, &root->children, child_node)
4373 		clk_core_evict_parent_cache_subtree(child, target);
4374 }
4375 
4376 /* Remove this clk from all parent caches */
clk_core_evict_parent_cache(struct clk_core * core)4377 static void clk_core_evict_parent_cache(struct clk_core *core)
4378 {
4379 	const struct hlist_head **lists;
4380 	struct clk_core *root;
4381 
4382 	lockdep_assert_held(&prepare_lock);
4383 
4384 	for (lists = all_lists; *lists; lists++)
4385 		hlist_for_each_entry(root, *lists, child_node)
4386 			clk_core_evict_parent_cache_subtree(root, core);
4387 
4388 }
4389 
4390 /**
4391  * clk_unregister - unregister a currently registered clock
4392  * @clk: clock to unregister
4393  */
clk_unregister(struct clk * clk)4394 void clk_unregister(struct clk *clk)
4395 {
4396 	unsigned long flags;
4397 	const struct clk_ops *ops;
4398 
4399 	if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4400 		return;
4401 
4402 	clk_debug_unregister(clk->core);
4403 
4404 	clk_prepare_lock();
4405 
4406 	ops = clk->core->ops;
4407 	if (ops == &clk_nodrv_ops) {
4408 		pr_err("%s: unregistered clock: %s\n", __func__,
4409 		       clk->core->name);
4410 		goto unlock;
4411 	}
4412 	/*
4413 	 * Assign empty clock ops for consumers that might still hold
4414 	 * a reference to this clock.
4415 	 */
4416 	flags = clk_enable_lock();
4417 	clk->core->ops = &clk_nodrv_ops;
4418 	clk_enable_unlock(flags);
4419 
4420 	if (ops->terminate)
4421 		ops->terminate(clk->core->hw);
4422 
4423 	if (!hlist_empty(&clk->core->children)) {
4424 		struct clk_core *child;
4425 		struct hlist_node *t;
4426 
4427 		/* Reparent all children to the orphan list. */
4428 		hlist_for_each_entry_safe(child, t, &clk->core->children,
4429 					  child_node)
4430 			clk_core_set_parent_nolock(child, NULL);
4431 	}
4432 
4433 	clk_core_evict_parent_cache(clk->core);
4434 
4435 	hlist_del_init(&clk->core->child_node);
4436 
4437 	if (clk->core->prepare_count)
4438 		pr_warn("%s: unregistering prepared clock: %s\n",
4439 					__func__, clk->core->name);
4440 
4441 	if (clk->core->protect_count)
4442 		pr_warn("%s: unregistering protected clock: %s\n",
4443 					__func__, clk->core->name);
4444 
4445 	kref_put(&clk->core->ref, __clk_release);
4446 	free_clk(clk);
4447 unlock:
4448 	clk_prepare_unlock();
4449 }
4450 EXPORT_SYMBOL_GPL(clk_unregister);
4451 
4452 /**
4453  * clk_hw_unregister - unregister a currently registered clk_hw
4454  * @hw: hardware-specific clock data to unregister
4455  */
clk_hw_unregister(struct clk_hw * hw)4456 void clk_hw_unregister(struct clk_hw *hw)
4457 {
4458 	clk_unregister(hw->clk);
4459 }
4460 EXPORT_SYMBOL_GPL(clk_hw_unregister);
4461 
devm_clk_unregister_cb(struct device * dev,void * res)4462 static void devm_clk_unregister_cb(struct device *dev, void *res)
4463 {
4464 	clk_unregister(*(struct clk **)res);
4465 }
4466 
devm_clk_hw_unregister_cb(struct device * dev,void * res)4467 static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
4468 {
4469 	clk_hw_unregister(*(struct clk_hw **)res);
4470 }
4471 
4472 /**
4473  * devm_clk_register - resource managed clk_register()
4474  * @dev: device that is registering this clock
4475  * @hw: link to hardware-specific clock data
4476  *
4477  * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4478  *
4479  * Clocks returned from this function are automatically clk_unregister()ed on
4480  * driver detach. See clk_register() for more information.
4481  */
devm_clk_register(struct device * dev,struct clk_hw * hw)4482 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4483 {
4484 	struct clk *clk;
4485 	struct clk **clkp;
4486 
4487 	clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL);
4488 	if (!clkp)
4489 		return ERR_PTR(-ENOMEM);
4490 
4491 	clk = clk_register(dev, hw);
4492 	if (!IS_ERR(clk)) {
4493 		*clkp = clk;
4494 		devres_add(dev, clkp);
4495 	} else {
4496 		devres_free(clkp);
4497 	}
4498 
4499 	return clk;
4500 }
4501 EXPORT_SYMBOL_GPL(devm_clk_register);
4502 
4503 /**
4504  * devm_clk_hw_register - resource managed clk_hw_register()
4505  * @dev: device that is registering this clock
4506  * @hw: link to hardware-specific clock data
4507  *
4508  * Managed clk_hw_register(). Clocks registered by this function are
4509  * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4510  * for more information.
4511  */
devm_clk_hw_register(struct device * dev,struct clk_hw * hw)4512 int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4513 {
4514 	struct clk_hw **hwp;
4515 	int ret;
4516 
4517 	hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
4518 	if (!hwp)
4519 		return -ENOMEM;
4520 
4521 	ret = clk_hw_register(dev, hw);
4522 	if (!ret) {
4523 		*hwp = hw;
4524 		devres_add(dev, hwp);
4525 	} else {
4526 		devres_free(hwp);
4527 	}
4528 
4529 	return ret;
4530 }
4531 EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4532 
devm_clk_release(struct device * dev,void * res)4533 static void devm_clk_release(struct device *dev, void *res)
4534 {
4535 	clk_put(*(struct clk **)res);
4536 }
4537 
4538 /**
4539  * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
4540  * @dev: device that is registering this clock
4541  * @hw: clk_hw associated with the clk being consumed
4542  * @con_id: connection ID string on device
4543  *
4544  * Managed clk_hw_get_clk(). Clocks got with this function are
4545  * automatically clk_put() on driver detach. See clk_put()
4546  * for more information.
4547  */
devm_clk_hw_get_clk(struct device * dev,struct clk_hw * hw,const char * con_id)4548 struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
4549 				const char *con_id)
4550 {
4551 	struct clk *clk;
4552 	struct clk **clkp;
4553 
4554 	/* This should not happen because it would mean we have drivers
4555 	 * passing around clk_hw pointers instead of having the caller use
4556 	 * proper clk_get() style APIs
4557 	 */
4558 	WARN_ON_ONCE(dev != hw->core->dev);
4559 
4560 	clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4561 	if (!clkp)
4562 		return ERR_PTR(-ENOMEM);
4563 
4564 	clk = clk_hw_get_clk(hw, con_id);
4565 	if (!IS_ERR(clk)) {
4566 		*clkp = clk;
4567 		devres_add(dev, clkp);
4568 	} else {
4569 		devres_free(clkp);
4570 	}
4571 
4572 	return clk;
4573 }
4574 EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
4575 
4576 /*
4577  * clkdev helpers
4578  */
4579 
__clk_put(struct clk * clk)4580 void __clk_put(struct clk *clk)
4581 {
4582 	struct module *owner;
4583 
4584 	if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4585 		return;
4586 
4587 	clk_prepare_lock();
4588 
4589 	/*
4590 	 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4591 	 * given user should be balanced with calls to clk_rate_exclusive_put()
4592 	 * and by that same consumer
4593 	 */
4594 	if (WARN_ON(clk->exclusive_count)) {
4595 		/* We voiced our concern, let's sanitize the situation */
4596 		clk->core->protect_count -= (clk->exclusive_count - 1);
4597 		clk_core_rate_unprotect(clk->core);
4598 		clk->exclusive_count = 0;
4599 	}
4600 
4601 	hlist_del(&clk->clks_node);
4602 
4603 	/* If we had any boundaries on that clock, let's drop them. */
4604 	if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX)
4605 		clk_set_rate_range_nolock(clk, 0, ULONG_MAX);
4606 
4607 	owner = clk->core->owner;
4608 	kref_put(&clk->core->ref, __clk_release);
4609 
4610 	clk_prepare_unlock();
4611 
4612 	module_put(owner);
4613 
4614 	free_clk(clk);
4615 }
4616 
4617 /***        clk rate change notifiers        ***/
4618 
4619 /**
4620  * clk_notifier_register - add a clk rate change notifier
4621  * @clk: struct clk * to watch
4622  * @nb: struct notifier_block * with callback info
4623  *
4624  * Request notification when clk's rate changes.  This uses an SRCU
4625  * notifier because we want it to block and notifier unregistrations are
4626  * uncommon.  The callbacks associated with the notifier must not
4627  * re-enter into the clk framework by calling any top-level clk APIs;
4628  * this will cause a nested prepare_lock mutex.
4629  *
4630  * In all notification cases (pre, post and abort rate change) the original
4631  * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4632  * and the new frequency is passed via struct clk_notifier_data.new_rate.
4633  *
4634  * clk_notifier_register() must be called from non-atomic context.
4635  * Returns -EINVAL if called with null arguments, -ENOMEM upon
4636  * allocation failure; otherwise, passes along the return value of
4637  * srcu_notifier_chain_register().
4638  */
clk_notifier_register(struct clk * clk,struct notifier_block * nb)4639 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4640 {
4641 	struct clk_notifier *cn;
4642 	int ret = -ENOMEM;
4643 
4644 	if (!clk || !nb)
4645 		return -EINVAL;
4646 
4647 	clk_prepare_lock();
4648 
4649 	/* search the list of notifiers for this clk */
4650 	list_for_each_entry(cn, &clk_notifier_list, node)
4651 		if (cn->clk == clk)
4652 			goto found;
4653 
4654 	/* if clk wasn't in the notifier list, allocate new clk_notifier */
4655 	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4656 	if (!cn)
4657 		goto out;
4658 
4659 	cn->clk = clk;
4660 	srcu_init_notifier_head(&cn->notifier_head);
4661 
4662 	list_add(&cn->node, &clk_notifier_list);
4663 
4664 found:
4665 	ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4666 
4667 	clk->core->notifier_count++;
4668 
4669 out:
4670 	clk_prepare_unlock();
4671 
4672 	return ret;
4673 }
4674 EXPORT_SYMBOL_GPL(clk_notifier_register);
4675 
4676 /**
4677  * clk_notifier_unregister - remove a clk rate change notifier
4678  * @clk: struct clk *
4679  * @nb: struct notifier_block * with callback info
4680  *
4681  * Request no further notification for changes to 'clk' and frees memory
4682  * allocated in clk_notifier_register.
4683  *
4684  * Returns -EINVAL if called with null arguments; otherwise, passes
4685  * along the return value of srcu_notifier_chain_unregister().
4686  */
clk_notifier_unregister(struct clk * clk,struct notifier_block * nb)4687 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4688 {
4689 	struct clk_notifier *cn;
4690 	int ret = -ENOENT;
4691 
4692 	if (!clk || !nb)
4693 		return -EINVAL;
4694 
4695 	clk_prepare_lock();
4696 
4697 	list_for_each_entry(cn, &clk_notifier_list, node) {
4698 		if (cn->clk == clk) {
4699 			ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4700 
4701 			clk->core->notifier_count--;
4702 
4703 			/* XXX the notifier code should handle this better */
4704 			if (!cn->notifier_head.head) {
4705 				srcu_cleanup_notifier_head(&cn->notifier_head);
4706 				list_del(&cn->node);
4707 				kfree(cn);
4708 			}
4709 			break;
4710 		}
4711 	}
4712 
4713 	clk_prepare_unlock();
4714 
4715 	return ret;
4716 }
4717 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4718 
4719 struct clk_notifier_devres {
4720 	struct clk *clk;
4721 	struct notifier_block *nb;
4722 };
4723 
devm_clk_notifier_release(struct device * dev,void * res)4724 static void devm_clk_notifier_release(struct device *dev, void *res)
4725 {
4726 	struct clk_notifier_devres *devres = res;
4727 
4728 	clk_notifier_unregister(devres->clk, devres->nb);
4729 }
4730 
devm_clk_notifier_register(struct device * dev,struct clk * clk,struct notifier_block * nb)4731 int devm_clk_notifier_register(struct device *dev, struct clk *clk,
4732 			       struct notifier_block *nb)
4733 {
4734 	struct clk_notifier_devres *devres;
4735 	int ret;
4736 
4737 	devres = devres_alloc(devm_clk_notifier_release,
4738 			      sizeof(*devres), GFP_KERNEL);
4739 
4740 	if (!devres)
4741 		return -ENOMEM;
4742 
4743 	ret = clk_notifier_register(clk, nb);
4744 	if (!ret) {
4745 		devres->clk = clk;
4746 		devres->nb = nb;
4747 		devres_add(dev, devres);
4748 	} else {
4749 		devres_free(devres);
4750 	}
4751 
4752 	return ret;
4753 }
4754 EXPORT_SYMBOL_GPL(devm_clk_notifier_register);
4755 
4756 #ifdef CONFIG_OF
clk_core_reparent_orphans(void)4757 static void clk_core_reparent_orphans(void)
4758 {
4759 	clk_prepare_lock();
4760 	clk_core_reparent_orphans_nolock();
4761 	clk_prepare_unlock();
4762 }
4763 
4764 /**
4765  * struct of_clk_provider - Clock provider registration structure
4766  * @link: Entry in global list of clock providers
4767  * @node: Pointer to device tree node of clock provider
4768  * @get: Get clock callback.  Returns NULL or a struct clk for the
4769  *       given clock specifier
4770  * @get_hw: Get clk_hw callback.  Returns NULL, ERR_PTR or a
4771  *       struct clk_hw for the given clock specifier
4772  * @data: context pointer to be passed into @get callback
4773  */
4774 struct of_clk_provider {
4775 	struct list_head link;
4776 
4777 	struct device_node *node;
4778 	struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4779 	struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4780 	void *data;
4781 };
4782 
4783 extern struct of_device_id __clk_of_table;
4784 static const struct of_device_id __clk_of_table_sentinel
4785 	__used __section("__clk_of_table_end");
4786 
4787 static LIST_HEAD(of_clk_providers);
4788 static DEFINE_MUTEX(of_clk_mutex);
4789 
of_clk_src_simple_get(struct of_phandle_args * clkspec,void * data)4790 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4791 				     void *data)
4792 {
4793 	return data;
4794 }
4795 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4796 
of_clk_hw_simple_get(struct of_phandle_args * clkspec,void * data)4797 struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4798 {
4799 	return data;
4800 }
4801 EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4802 
of_clk_src_onecell_get(struct of_phandle_args * clkspec,void * data)4803 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4804 {
4805 	struct clk_onecell_data *clk_data = data;
4806 	unsigned int idx = clkspec->args[0];
4807 
4808 	if (idx >= clk_data->clk_num) {
4809 		pr_err("%s: invalid clock index %u\n", __func__, idx);
4810 		return ERR_PTR(-EINVAL);
4811 	}
4812 
4813 	return clk_data->clks[idx];
4814 }
4815 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4816 
4817 struct clk_hw *
of_clk_hw_onecell_get(struct of_phandle_args * clkspec,void * data)4818 of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4819 {
4820 	struct clk_hw_onecell_data *hw_data = data;
4821 	unsigned int idx = clkspec->args[0];
4822 
4823 	if (idx >= hw_data->num) {
4824 		pr_err("%s: invalid index %u\n", __func__, idx);
4825 		return ERR_PTR(-EINVAL);
4826 	}
4827 
4828 	return hw_data->hws[idx];
4829 }
4830 EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4831 
4832 /**
4833  * of_clk_add_provider() - Register a clock provider for a node
4834  * @np: Device node pointer associated with clock provider
4835  * @clk_src_get: callback for decoding clock
4836  * @data: context pointer for @clk_src_get callback.
4837  *
4838  * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4839  */
of_clk_add_provider(struct device_node * np,struct clk * (* clk_src_get)(struct of_phandle_args * clkspec,void * data),void * data)4840 int of_clk_add_provider(struct device_node *np,
4841 			struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4842 						   void *data),
4843 			void *data)
4844 {
4845 	struct of_clk_provider *cp;
4846 	int ret;
4847 
4848 	if (!np)
4849 		return 0;
4850 
4851 	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4852 	if (!cp)
4853 		return -ENOMEM;
4854 
4855 	cp->node = of_node_get(np);
4856 	cp->data = data;
4857 	cp->get = clk_src_get;
4858 
4859 	mutex_lock(&of_clk_mutex);
4860 	list_add(&cp->link, &of_clk_providers);
4861 	mutex_unlock(&of_clk_mutex);
4862 	pr_debug("Added clock from %pOF\n", np);
4863 
4864 	clk_core_reparent_orphans();
4865 
4866 	ret = of_clk_set_defaults(np, true);
4867 	if (ret < 0)
4868 		of_clk_del_provider(np);
4869 
4870 	fwnode_dev_initialized(&np->fwnode, true);
4871 
4872 	return ret;
4873 }
4874 EXPORT_SYMBOL_GPL(of_clk_add_provider);
4875 
4876 /**
4877  * of_clk_add_hw_provider() - Register a clock provider for a node
4878  * @np: Device node pointer associated with clock provider
4879  * @get: callback for decoding clk_hw
4880  * @data: context pointer for @get callback.
4881  */
of_clk_add_hw_provider(struct device_node * np,struct clk_hw * (* get)(struct of_phandle_args * clkspec,void * data),void * data)4882 int of_clk_add_hw_provider(struct device_node *np,
4883 			   struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4884 						 void *data),
4885 			   void *data)
4886 {
4887 	struct of_clk_provider *cp;
4888 	int ret;
4889 
4890 	if (!np)
4891 		return 0;
4892 
4893 	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4894 	if (!cp)
4895 		return -ENOMEM;
4896 
4897 	cp->node = of_node_get(np);
4898 	cp->data = data;
4899 	cp->get_hw = get;
4900 
4901 	mutex_lock(&of_clk_mutex);
4902 	list_add(&cp->link, &of_clk_providers);
4903 	mutex_unlock(&of_clk_mutex);
4904 	pr_debug("Added clk_hw provider from %pOF\n", np);
4905 
4906 	clk_core_reparent_orphans();
4907 
4908 	ret = of_clk_set_defaults(np, true);
4909 	if (ret < 0)
4910 		of_clk_del_provider(np);
4911 
4912 	fwnode_dev_initialized(&np->fwnode, true);
4913 
4914 	return ret;
4915 }
4916 EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
4917 
devm_of_clk_release_provider(struct device * dev,void * res)4918 static void devm_of_clk_release_provider(struct device *dev, void *res)
4919 {
4920 	of_clk_del_provider(*(struct device_node **)res);
4921 }
4922 
4923 /*
4924  * We allow a child device to use its parent device as the clock provider node
4925  * for cases like MFD sub-devices where the child device driver wants to use
4926  * devm_*() APIs but not list the device in DT as a sub-node.
4927  */
get_clk_provider_node(struct device * dev)4928 static struct device_node *get_clk_provider_node(struct device *dev)
4929 {
4930 	struct device_node *np, *parent_np;
4931 
4932 	np = dev->of_node;
4933 	parent_np = dev->parent ? dev->parent->of_node : NULL;
4934 
4935 	if (!of_property_present(np, "#clock-cells"))
4936 		if (of_property_present(parent_np, "#clock-cells"))
4937 			np = parent_np;
4938 
4939 	return np;
4940 }
4941 
4942 /**
4943  * devm_of_clk_add_hw_provider() - Managed clk provider node registration
4944  * @dev: Device acting as the clock provider (used for DT node and lifetime)
4945  * @get: callback for decoding clk_hw
4946  * @data: context pointer for @get callback
4947  *
4948  * Registers clock provider for given device's node. If the device has no DT
4949  * node or if the device node lacks of clock provider information (#clock-cells)
4950  * then the parent device's node is scanned for this information. If parent node
4951  * has the #clock-cells then it is used in registration. Provider is
4952  * automatically released at device exit.
4953  *
4954  * Return: 0 on success or an errno on failure.
4955  */
devm_of_clk_add_hw_provider(struct device * dev,struct clk_hw * (* get)(struct of_phandle_args * clkspec,void * data),void * data)4956 int devm_of_clk_add_hw_provider(struct device *dev,
4957 			struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4958 					      void *data),
4959 			void *data)
4960 {
4961 	struct device_node **ptr, *np;
4962 	int ret;
4963 
4964 	ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
4965 			   GFP_KERNEL);
4966 	if (!ptr)
4967 		return -ENOMEM;
4968 
4969 	np = get_clk_provider_node(dev);
4970 	ret = of_clk_add_hw_provider(np, get, data);
4971 	if (!ret) {
4972 		*ptr = np;
4973 		devres_add(dev, ptr);
4974 	} else {
4975 		devres_free(ptr);
4976 	}
4977 
4978 	return ret;
4979 }
4980 EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
4981 
4982 /**
4983  * of_clk_del_provider() - Remove a previously registered clock provider
4984  * @np: Device node pointer associated with clock provider
4985  */
of_clk_del_provider(struct device_node * np)4986 void of_clk_del_provider(struct device_node *np)
4987 {
4988 	struct of_clk_provider *cp;
4989 
4990 	if (!np)
4991 		return;
4992 
4993 	mutex_lock(&of_clk_mutex);
4994 	list_for_each_entry(cp, &of_clk_providers, link) {
4995 		if (cp->node == np) {
4996 			list_del(&cp->link);
4997 			fwnode_dev_initialized(&np->fwnode, false);
4998 			of_node_put(cp->node);
4999 			kfree(cp);
5000 			break;
5001 		}
5002 	}
5003 	mutex_unlock(&of_clk_mutex);
5004 }
5005 EXPORT_SYMBOL_GPL(of_clk_del_provider);
5006 
5007 /**
5008  * of_parse_clkspec() - Parse a DT clock specifier for a given device node
5009  * @np: device node to parse clock specifier from
5010  * @index: index of phandle to parse clock out of. If index < 0, @name is used
5011  * @name: clock name to find and parse. If name is NULL, the index is used
5012  * @out_args: Result of parsing the clock specifier
5013  *
5014  * Parses a device node's "clocks" and "clock-names" properties to find the
5015  * phandle and cells for the index or name that is desired. The resulting clock
5016  * specifier is placed into @out_args, or an errno is returned when there's a
5017  * parsing error. The @index argument is ignored if @name is non-NULL.
5018  *
5019  * Example:
5020  *
5021  * phandle1: clock-controller@1 {
5022  *	#clock-cells = <2>;
5023  * }
5024  *
5025  * phandle2: clock-controller@2 {
5026  *	#clock-cells = <1>;
5027  * }
5028  *
5029  * clock-consumer@3 {
5030  *	clocks = <&phandle1 1 2 &phandle2 3>;
5031  *	clock-names = "name1", "name2";
5032  * }
5033  *
5034  * To get a device_node for `clock-controller@2' node you may call this
5035  * function a few different ways:
5036  *
5037  *   of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
5038  *   of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
5039  *   of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
5040  *
5041  * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
5042  * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
5043  * the "clock-names" property of @np.
5044  */
of_parse_clkspec(const struct device_node * np,int index,const char * name,struct of_phandle_args * out_args)5045 static int of_parse_clkspec(const struct device_node *np, int index,
5046 			    const char *name, struct of_phandle_args *out_args)
5047 {
5048 	int ret = -ENOENT;
5049 
5050 	/* Walk up the tree of devices looking for a clock property that matches */
5051 	while (np) {
5052 		/*
5053 		 * For named clocks, first look up the name in the
5054 		 * "clock-names" property.  If it cannot be found, then index
5055 		 * will be an error code and of_parse_phandle_with_args() will
5056 		 * return -EINVAL.
5057 		 */
5058 		if (name)
5059 			index = of_property_match_string(np, "clock-names", name);
5060 		ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
5061 						 index, out_args);
5062 		if (!ret)
5063 			break;
5064 		if (name && index >= 0)
5065 			break;
5066 
5067 		/*
5068 		 * No matching clock found on this node.  If the parent node
5069 		 * has a "clock-ranges" property, then we can try one of its
5070 		 * clocks.
5071 		 */
5072 		np = np->parent;
5073 		if (np && !of_get_property(np, "clock-ranges", NULL))
5074 			break;
5075 		index = 0;
5076 	}
5077 
5078 	return ret;
5079 }
5080 
5081 static struct clk_hw *
__of_clk_get_hw_from_provider(struct of_clk_provider * provider,struct of_phandle_args * clkspec)5082 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
5083 			      struct of_phandle_args *clkspec)
5084 {
5085 	struct clk *clk;
5086 
5087 	if (provider->get_hw)
5088 		return provider->get_hw(clkspec, provider->data);
5089 
5090 	clk = provider->get(clkspec, provider->data);
5091 	if (IS_ERR(clk))
5092 		return ERR_CAST(clk);
5093 	return __clk_get_hw(clk);
5094 }
5095 
5096 static struct clk_hw *
of_clk_get_hw_from_clkspec(struct of_phandle_args * clkspec)5097 of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
5098 {
5099 	struct of_clk_provider *provider;
5100 	struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
5101 
5102 	if (!clkspec)
5103 		return ERR_PTR(-EINVAL);
5104 
5105 	mutex_lock(&of_clk_mutex);
5106 	list_for_each_entry(provider, &of_clk_providers, link) {
5107 		if (provider->node == clkspec->np) {
5108 			hw = __of_clk_get_hw_from_provider(provider, clkspec);
5109 			if (!IS_ERR(hw))
5110 				break;
5111 		}
5112 	}
5113 	mutex_unlock(&of_clk_mutex);
5114 
5115 	return hw;
5116 }
5117 
5118 /**
5119  * of_clk_get_from_provider() - Lookup a clock from a clock provider
5120  * @clkspec: pointer to a clock specifier data structure
5121  *
5122  * This function looks up a struct clk from the registered list of clock
5123  * providers, an input is a clock specifier data structure as returned
5124  * from the of_parse_phandle_with_args() function call.
5125  */
of_clk_get_from_provider(struct of_phandle_args * clkspec)5126 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
5127 {
5128 	struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
5129 
5130 	return clk_hw_create_clk(NULL, hw, NULL, __func__);
5131 }
5132 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
5133 
of_clk_get_hw(struct device_node * np,int index,const char * con_id)5134 struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
5135 			     const char *con_id)
5136 {
5137 	int ret;
5138 	struct clk_hw *hw;
5139 	struct of_phandle_args clkspec;
5140 
5141 	ret = of_parse_clkspec(np, index, con_id, &clkspec);
5142 	if (ret)
5143 		return ERR_PTR(ret);
5144 
5145 	hw = of_clk_get_hw_from_clkspec(&clkspec);
5146 	of_node_put(clkspec.np);
5147 
5148 	return hw;
5149 }
5150 
__of_clk_get(struct device_node * np,int index,const char * dev_id,const char * con_id)5151 static struct clk *__of_clk_get(struct device_node *np,
5152 				int index, const char *dev_id,
5153 				const char *con_id)
5154 {
5155 	struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
5156 
5157 	return clk_hw_create_clk(NULL, hw, dev_id, con_id);
5158 }
5159 
of_clk_get(struct device_node * np,int index)5160 struct clk *of_clk_get(struct device_node *np, int index)
5161 {
5162 	return __of_clk_get(np, index, np->full_name, NULL);
5163 }
5164 EXPORT_SYMBOL(of_clk_get);
5165 
5166 /**
5167  * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
5168  * @np: pointer to clock consumer node
5169  * @name: name of consumer's clock input, or NULL for the first clock reference
5170  *
5171  * This function parses the clocks and clock-names properties,
5172  * and uses them to look up the struct clk from the registered list of clock
5173  * providers.
5174  */
of_clk_get_by_name(struct device_node * np,const char * name)5175 struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
5176 {
5177 	if (!np)
5178 		return ERR_PTR(-ENOENT);
5179 
5180 	return __of_clk_get(np, 0, np->full_name, name);
5181 }
5182 EXPORT_SYMBOL(of_clk_get_by_name);
5183 
5184 /**
5185  * of_clk_get_parent_count() - Count the number of clocks a device node has
5186  * @np: device node to count
5187  *
5188  * Returns: The number of clocks that are possible parents of this node
5189  */
of_clk_get_parent_count(const struct device_node * np)5190 unsigned int of_clk_get_parent_count(const struct device_node *np)
5191 {
5192 	int count;
5193 
5194 	count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
5195 	if (count < 0)
5196 		return 0;
5197 
5198 	return count;
5199 }
5200 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
5201 
of_clk_get_parent_name(const struct device_node * np,int index)5202 const char *of_clk_get_parent_name(const struct device_node *np, int index)
5203 {
5204 	struct of_phandle_args clkspec;
5205 	struct property *prop;
5206 	const char *clk_name;
5207 	const __be32 *vp;
5208 	u32 pv;
5209 	int rc;
5210 	int count;
5211 	struct clk *clk;
5212 
5213 	rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
5214 					&clkspec);
5215 	if (rc)
5216 		return NULL;
5217 
5218 	index = clkspec.args_count ? clkspec.args[0] : 0;
5219 	count = 0;
5220 
5221 	/* if there is an indices property, use it to transfer the index
5222 	 * specified into an array offset for the clock-output-names property.
5223 	 */
5224 	of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
5225 		if (index == pv) {
5226 			index = count;
5227 			break;
5228 		}
5229 		count++;
5230 	}
5231 	/* We went off the end of 'clock-indices' without finding it */
5232 	if (prop && !vp)
5233 		return NULL;
5234 
5235 	if (of_property_read_string_index(clkspec.np, "clock-output-names",
5236 					  index,
5237 					  &clk_name) < 0) {
5238 		/*
5239 		 * Best effort to get the name if the clock has been
5240 		 * registered with the framework. If the clock isn't
5241 		 * registered, we return the node name as the name of
5242 		 * the clock as long as #clock-cells = 0.
5243 		 */
5244 		clk = of_clk_get_from_provider(&clkspec);
5245 		if (IS_ERR(clk)) {
5246 			if (clkspec.args_count == 0)
5247 				clk_name = clkspec.np->name;
5248 			else
5249 				clk_name = NULL;
5250 		} else {
5251 			clk_name = __clk_get_name(clk);
5252 			clk_put(clk);
5253 		}
5254 	}
5255 
5256 
5257 	of_node_put(clkspec.np);
5258 	return clk_name;
5259 }
5260 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
5261 
5262 /**
5263  * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
5264  * number of parents
5265  * @np: Device node pointer associated with clock provider
5266  * @parents: pointer to char array that hold the parents' names
5267  * @size: size of the @parents array
5268  *
5269  * Return: number of parents for the clock node.
5270  */
of_clk_parent_fill(struct device_node * np,const char ** parents,unsigned int size)5271 int of_clk_parent_fill(struct device_node *np, const char **parents,
5272 		       unsigned int size)
5273 {
5274 	unsigned int i = 0;
5275 
5276 	while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
5277 		i++;
5278 
5279 	return i;
5280 }
5281 EXPORT_SYMBOL_GPL(of_clk_parent_fill);
5282 
5283 struct clock_provider {
5284 	void (*clk_init_cb)(struct device_node *);
5285 	struct device_node *np;
5286 	struct list_head node;
5287 };
5288 
5289 /*
5290  * This function looks for a parent clock. If there is one, then it
5291  * checks that the provider for this parent clock was initialized, in
5292  * this case the parent clock will be ready.
5293  */
parent_ready(struct device_node * np)5294 static int parent_ready(struct device_node *np)
5295 {
5296 	int i = 0;
5297 
5298 	while (true) {
5299 		struct clk *clk = of_clk_get(np, i);
5300 
5301 		/* this parent is ready we can check the next one */
5302 		if (!IS_ERR(clk)) {
5303 			clk_put(clk);
5304 			i++;
5305 			continue;
5306 		}
5307 
5308 		/* at least one parent is not ready, we exit now */
5309 		if (PTR_ERR(clk) == -EPROBE_DEFER)
5310 			return 0;
5311 
5312 		/*
5313 		 * Here we make assumption that the device tree is
5314 		 * written correctly. So an error means that there is
5315 		 * no more parent. As we didn't exit yet, then the
5316 		 * previous parent are ready. If there is no clock
5317 		 * parent, no need to wait for them, then we can
5318 		 * consider their absence as being ready
5319 		 */
5320 		return 1;
5321 	}
5322 }
5323 
5324 /**
5325  * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
5326  * @np: Device node pointer associated with clock provider
5327  * @index: clock index
5328  * @flags: pointer to top-level framework flags
5329  *
5330  * Detects if the clock-critical property exists and, if so, sets the
5331  * corresponding CLK_IS_CRITICAL flag.
5332  *
5333  * Do not use this function. It exists only for legacy Device Tree
5334  * bindings, such as the one-clock-per-node style that are outdated.
5335  * Those bindings typically put all clock data into .dts and the Linux
5336  * driver has no clock data, thus making it impossible to set this flag
5337  * correctly from the driver. Only those drivers may call
5338  * of_clk_detect_critical from their setup functions.
5339  *
5340  * Return: error code or zero on success
5341  */
of_clk_detect_critical(struct device_node * np,int index,unsigned long * flags)5342 int of_clk_detect_critical(struct device_node *np, int index,
5343 			   unsigned long *flags)
5344 {
5345 	struct property *prop;
5346 	const __be32 *cur;
5347 	uint32_t idx;
5348 
5349 	if (!np || !flags)
5350 		return -EINVAL;
5351 
5352 	of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
5353 		if (index == idx)
5354 			*flags |= CLK_IS_CRITICAL;
5355 
5356 	return 0;
5357 }
5358 
5359 /**
5360  * of_clk_init() - Scan and init clock providers from the DT
5361  * @matches: array of compatible values and init functions for providers.
5362  *
5363  * This function scans the device tree for matching clock providers
5364  * and calls their initialization functions. It also does it by trying
5365  * to follow the dependencies.
5366  */
of_clk_init(const struct of_device_id * matches)5367 void __init of_clk_init(const struct of_device_id *matches)
5368 {
5369 	const struct of_device_id *match;
5370 	struct device_node *np;
5371 	struct clock_provider *clk_provider, *next;
5372 	bool is_init_done;
5373 	bool force = false;
5374 	LIST_HEAD(clk_provider_list);
5375 
5376 	if (!matches)
5377 		matches = &__clk_of_table;
5378 
5379 	/* First prepare the list of the clocks providers */
5380 	for_each_matching_node_and_match(np, matches, &match) {
5381 		struct clock_provider *parent;
5382 
5383 		if (!of_device_is_available(np))
5384 			continue;
5385 
5386 		parent = kzalloc(sizeof(*parent), GFP_KERNEL);
5387 		if (!parent) {
5388 			list_for_each_entry_safe(clk_provider, next,
5389 						 &clk_provider_list, node) {
5390 				list_del(&clk_provider->node);
5391 				of_node_put(clk_provider->np);
5392 				kfree(clk_provider);
5393 			}
5394 			of_node_put(np);
5395 			return;
5396 		}
5397 
5398 		parent->clk_init_cb = match->data;
5399 		parent->np = of_node_get(np);
5400 		list_add_tail(&parent->node, &clk_provider_list);
5401 	}
5402 
5403 	while (!list_empty(&clk_provider_list)) {
5404 		is_init_done = false;
5405 		list_for_each_entry_safe(clk_provider, next,
5406 					&clk_provider_list, node) {
5407 			if (force || parent_ready(clk_provider->np)) {
5408 
5409 				/* Don't populate platform devices */
5410 				of_node_set_flag(clk_provider->np,
5411 						 OF_POPULATED);
5412 
5413 				clk_provider->clk_init_cb(clk_provider->np);
5414 				of_clk_set_defaults(clk_provider->np, true);
5415 
5416 				list_del(&clk_provider->node);
5417 				of_node_put(clk_provider->np);
5418 				kfree(clk_provider);
5419 				is_init_done = true;
5420 			}
5421 		}
5422 
5423 		/*
5424 		 * We didn't manage to initialize any of the
5425 		 * remaining providers during the last loop, so now we
5426 		 * initialize all the remaining ones unconditionally
5427 		 * in case the clock parent was not mandatory
5428 		 */
5429 		if (!is_init_done)
5430 			force = true;
5431 	}
5432 }
5433 #endif
5434