1 /*
2 * OMAP2/3/4 clockdomain framework functions
3 *
4 * Copyright (C) 2008-2010 Texas Instruments, Inc.
5 * Copyright (C) 2008-2010 Nokia Corporation
6 *
7 * Written by Paul Walmsley and Jouni Högander
8 * Added OMAP4 specific support by Abhijit Pagare <abhijitpagare@ti.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14 #undef DEBUG
15
16 #include <linux/kernel.h>
17 #include <linux/device.h>
18 #include <linux/list.h>
19 #include <linux/errno.h>
20 #include <linux/delay.h>
21 #include <linux/clk.h>
22 #include <linux/limits.h>
23 #include <linux/err.h>
24
25 #include <linux/io.h>
26
27 #include <linux/bitops.h>
28
29 #include <plat/clock.h>
30 #include "clockdomain.h"
31
32 /* clkdm_list contains all registered struct clockdomains */
33 static LIST_HEAD(clkdm_list);
34
35 /* array of clockdomain deps to be added/removed when clkdm in hwsup mode */
36 static struct clkdm_autodep *autodeps;
37
38 static struct clkdm_ops *arch_clkdm;
39
40 /* Private functions */
41
_clkdm_lookup(const char * name)42 static struct clockdomain *_clkdm_lookup(const char *name)
43 {
44 struct clockdomain *clkdm, *temp_clkdm;
45
46 if (!name)
47 return NULL;
48
49 clkdm = NULL;
50
51 list_for_each_entry(temp_clkdm, &clkdm_list, node) {
52 if (!strcmp(name, temp_clkdm->name)) {
53 clkdm = temp_clkdm;
54 break;
55 }
56 }
57
58 return clkdm;
59 }
60
61 /**
62 * _clkdm_register - register a clockdomain
63 * @clkdm: struct clockdomain * to register
64 *
65 * Adds a clockdomain to the internal clockdomain list.
66 * Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is
67 * already registered by the provided name, or 0 upon success.
68 */
_clkdm_register(struct clockdomain * clkdm)69 static int _clkdm_register(struct clockdomain *clkdm)
70 {
71 struct powerdomain *pwrdm;
72
73 if (!clkdm || !clkdm->name)
74 return -EINVAL;
75
76 if (!omap_chip_is(clkdm->omap_chip))
77 return -EINVAL;
78
79 pwrdm = pwrdm_lookup(clkdm->pwrdm.name);
80 if (!pwrdm) {
81 pr_err("clockdomain: %s: powerdomain %s does not exist\n",
82 clkdm->name, clkdm->pwrdm.name);
83 return -EINVAL;
84 }
85 clkdm->pwrdm.ptr = pwrdm;
86
87 /* Verify that the clockdomain is not already registered */
88 if (_clkdm_lookup(clkdm->name))
89 return -EEXIST;
90
91 list_add(&clkdm->node, &clkdm_list);
92
93 pwrdm_add_clkdm(pwrdm, clkdm);
94
95 pr_debug("clockdomain: registered %s\n", clkdm->name);
96
97 return 0;
98 }
99
100 /* _clkdm_deps_lookup - look up the specified clockdomain in a clkdm list */
_clkdm_deps_lookup(struct clockdomain * clkdm,struct clkdm_dep * deps)101 static struct clkdm_dep *_clkdm_deps_lookup(struct clockdomain *clkdm,
102 struct clkdm_dep *deps)
103 {
104 struct clkdm_dep *cd;
105
106 if (!clkdm || !deps || !omap_chip_is(clkdm->omap_chip))
107 return ERR_PTR(-EINVAL);
108
109 for (cd = deps; cd->clkdm_name; cd++) {
110 if (!omap_chip_is(cd->omap_chip))
111 continue;
112
113 if (!cd->clkdm && cd->clkdm_name)
114 cd->clkdm = _clkdm_lookup(cd->clkdm_name);
115
116 if (cd->clkdm == clkdm)
117 break;
118 }
119
120 if (!cd->clkdm_name)
121 return ERR_PTR(-ENOENT);
122
123 return cd;
124 }
125
126 /*
127 * _autodep_lookup - resolve autodep clkdm names to clkdm pointers; store
128 * @autodep: struct clkdm_autodep * to resolve
129 *
130 * Resolve autodep clockdomain names to clockdomain pointers via
131 * clkdm_lookup() and store the pointers in the autodep structure. An
132 * "autodep" is a clockdomain sleep/wakeup dependency that is
133 * automatically added and removed whenever clocks in the associated
134 * clockdomain are enabled or disabled (respectively) when the
135 * clockdomain is in hardware-supervised mode. Meant to be called
136 * once at clockdomain layer initialization, since these should remain
137 * fixed for a particular architecture. No return value.
138 *
139 * XXX autodeps are deprecated and should be removed at the earliest
140 * opportunity
141 */
_autodep_lookup(struct clkdm_autodep * autodep)142 static void _autodep_lookup(struct clkdm_autodep *autodep)
143 {
144 struct clockdomain *clkdm;
145
146 if (!autodep)
147 return;
148
149 if (!omap_chip_is(autodep->omap_chip))
150 return;
151
152 clkdm = clkdm_lookup(autodep->clkdm.name);
153 if (!clkdm) {
154 pr_err("clockdomain: autodeps: clockdomain %s does not exist\n",
155 autodep->clkdm.name);
156 clkdm = ERR_PTR(-ENOENT);
157 }
158 autodep->clkdm.ptr = clkdm;
159 }
160
161 /*
162 * _clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
163 * @clkdm: struct clockdomain *
164 *
165 * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
166 * in hardware-supervised mode. Meant to be called from clock framework
167 * when a clock inside clockdomain 'clkdm' is enabled. No return value.
168 *
169 * XXX autodeps are deprecated and should be removed at the earliest
170 * opportunity
171 */
_clkdm_add_autodeps(struct clockdomain * clkdm)172 void _clkdm_add_autodeps(struct clockdomain *clkdm)
173 {
174 struct clkdm_autodep *autodep;
175
176 if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
177 return;
178
179 for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
180 if (IS_ERR(autodep->clkdm.ptr))
181 continue;
182
183 if (!omap_chip_is(autodep->omap_chip))
184 continue;
185
186 pr_debug("clockdomain: adding %s sleepdep/wkdep for "
187 "clkdm %s\n", autodep->clkdm.ptr->name,
188 clkdm->name);
189
190 clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
191 clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
192 }
193 }
194
195 /*
196 * _clkdm_add_autodeps - remove auto sleepdeps/wkdeps from clkdm
197 * @clkdm: struct clockdomain *
198 *
199 * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
200 * in hardware-supervised mode. Meant to be called from clock framework
201 * when a clock inside clockdomain 'clkdm' is disabled. No return value.
202 *
203 * XXX autodeps are deprecated and should be removed at the earliest
204 * opportunity
205 */
_clkdm_del_autodeps(struct clockdomain * clkdm)206 void _clkdm_del_autodeps(struct clockdomain *clkdm)
207 {
208 struct clkdm_autodep *autodep;
209
210 if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
211 return;
212
213 for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
214 if (IS_ERR(autodep->clkdm.ptr))
215 continue;
216
217 if (!omap_chip_is(autodep->omap_chip))
218 continue;
219
220 pr_debug("clockdomain: removing %s sleepdep/wkdep for "
221 "clkdm %s\n", autodep->clkdm.ptr->name,
222 clkdm->name);
223
224 clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
225 clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
226 }
227 }
228
229 /**
230 * _resolve_clkdm_deps() - resolve clkdm_names in @clkdm_deps to clkdms
231 * @clkdm: clockdomain that we are resolving dependencies for
232 * @clkdm_deps: ptr to array of struct clkdm_deps to resolve
233 *
234 * Iterates through @clkdm_deps, looking up the struct clockdomain named by
235 * clkdm_name and storing the clockdomain pointer in the struct clkdm_dep.
236 * No return value.
237 */
_resolve_clkdm_deps(struct clockdomain * clkdm,struct clkdm_dep * clkdm_deps)238 static void _resolve_clkdm_deps(struct clockdomain *clkdm,
239 struct clkdm_dep *clkdm_deps)
240 {
241 struct clkdm_dep *cd;
242
243 for (cd = clkdm_deps; cd && cd->clkdm_name; cd++) {
244 if (!omap_chip_is(cd->omap_chip))
245 continue;
246 if (cd->clkdm)
247 continue;
248 cd->clkdm = _clkdm_lookup(cd->clkdm_name);
249
250 WARN(!cd->clkdm, "clockdomain: %s: could not find clkdm %s while resolving dependencies - should never happen",
251 clkdm->name, cd->clkdm_name);
252 }
253 }
254
255 /* Public functions */
256
257 /**
258 * clkdm_init - set up the clockdomain layer
259 * @clkdms: optional pointer to an array of clockdomains to register
260 * @init_autodeps: optional pointer to an array of autodeps to register
261 * @custom_funcs: func pointers for arch specific implementations
262 *
263 * Set up internal state. If a pointer to an array of clockdomains
264 * @clkdms was supplied, loop through the list of clockdomains,
265 * register all that are available on the current platform. Similarly,
266 * if a pointer to an array of clockdomain autodependencies
267 * @init_autodeps was provided, register those. No return value.
268 */
clkdm_init(struct clockdomain ** clkdms,struct clkdm_autodep * init_autodeps,struct clkdm_ops * custom_funcs)269 void clkdm_init(struct clockdomain **clkdms,
270 struct clkdm_autodep *init_autodeps,
271 struct clkdm_ops *custom_funcs)
272 {
273 struct clockdomain **c = NULL;
274 struct clockdomain *clkdm;
275 struct clkdm_autodep *autodep = NULL;
276
277 if (!custom_funcs)
278 WARN(1, "No custom clkdm functions registered\n");
279 else
280 arch_clkdm = custom_funcs;
281
282 if (clkdms)
283 for (c = clkdms; *c; c++)
284 _clkdm_register(*c);
285
286 autodeps = init_autodeps;
287 if (autodeps)
288 for (autodep = autodeps; autodep->clkdm.ptr; autodep++)
289 _autodep_lookup(autodep);
290
291 /*
292 * Put all clockdomains into software-supervised mode; PM code
293 * should later enable hardware-supervised mode as appropriate
294 */
295 list_for_each_entry(clkdm, &clkdm_list, node) {
296 if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
297 clkdm_wakeup(clkdm);
298 else if (clkdm->flags & CLKDM_CAN_DISABLE_AUTO)
299 clkdm_deny_idle(clkdm);
300
301 _resolve_clkdm_deps(clkdm, clkdm->wkdep_srcs);
302 clkdm_clear_all_wkdeps(clkdm);
303
304 _resolve_clkdm_deps(clkdm, clkdm->sleepdep_srcs);
305 clkdm_clear_all_sleepdeps(clkdm);
306 }
307 }
308
309 /**
310 * clkdm_lookup - look up a clockdomain by name, return a pointer
311 * @name: name of clockdomain
312 *
313 * Find a registered clockdomain by its name @name. Returns a pointer
314 * to the struct clockdomain if found, or NULL otherwise.
315 */
clkdm_lookup(const char * name)316 struct clockdomain *clkdm_lookup(const char *name)
317 {
318 struct clockdomain *clkdm, *temp_clkdm;
319
320 if (!name)
321 return NULL;
322
323 clkdm = NULL;
324
325 list_for_each_entry(temp_clkdm, &clkdm_list, node) {
326 if (!strcmp(name, temp_clkdm->name)) {
327 clkdm = temp_clkdm;
328 break;
329 }
330 }
331
332 return clkdm;
333 }
334
335 /**
336 * clkdm_for_each - call function on each registered clockdomain
337 * @fn: callback function *
338 *
339 * Call the supplied function @fn for each registered clockdomain.
340 * The callback function @fn can return anything but 0 to bail
341 * out early from the iterator. The callback function is called with
342 * the clkdm_mutex held, so no clockdomain structure manipulation
343 * functions should be called from the callback, although hardware
344 * clockdomain control functions are fine. Returns the last return
345 * value of the callback function, which should be 0 for success or
346 * anything else to indicate failure; or -EINVAL if the function pointer
347 * is null.
348 */
clkdm_for_each(int (* fn)(struct clockdomain * clkdm,void * user),void * user)349 int clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user),
350 void *user)
351 {
352 struct clockdomain *clkdm;
353 int ret = 0;
354
355 if (!fn)
356 return -EINVAL;
357
358 list_for_each_entry(clkdm, &clkdm_list, node) {
359 ret = (*fn)(clkdm, user);
360 if (ret)
361 break;
362 }
363
364 return ret;
365 }
366
367
368 /**
369 * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
370 * @clkdm: struct clockdomain *
371 *
372 * Return a pointer to the struct powerdomain that the specified clockdomain
373 * @clkdm exists in, or returns NULL if @clkdm is NULL.
374 */
clkdm_get_pwrdm(struct clockdomain * clkdm)375 struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
376 {
377 if (!clkdm)
378 return NULL;
379
380 return clkdm->pwrdm.ptr;
381 }
382
383
384 /* Hardware clockdomain control */
385
386 /**
387 * clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1
388 * @clkdm1: wake this struct clockdomain * up (dependent)
389 * @clkdm2: when this struct clockdomain * wakes up (source)
390 *
391 * When the clockdomain represented by @clkdm2 wakes up, wake up
392 * @clkdm1. Implemented in hardware on the OMAP, this feature is
393 * designed to reduce wakeup latency of the dependent clockdomain @clkdm1.
394 * Returns -EINVAL if presented with invalid clockdomain pointers,
395 * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon
396 * success.
397 */
clkdm_add_wkdep(struct clockdomain * clkdm1,struct clockdomain * clkdm2)398 int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
399 {
400 struct clkdm_dep *cd;
401 int ret = 0;
402
403 if (!clkdm1 || !clkdm2)
404 return -EINVAL;
405
406 cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
407 if (IS_ERR(cd))
408 ret = PTR_ERR(cd);
409
410 if (!arch_clkdm || !arch_clkdm->clkdm_add_wkdep)
411 ret = -EINVAL;
412
413 if (ret) {
414 pr_debug("clockdomain: hardware cannot set/clear wake up of "
415 "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
416 return ret;
417 }
418
419 if (atomic_inc_return(&cd->wkdep_usecount) == 1) {
420 pr_debug("clockdomain: hardware will wake up %s when %s wakes "
421 "up\n", clkdm1->name, clkdm2->name);
422
423 ret = arch_clkdm->clkdm_add_wkdep(clkdm1, clkdm2);
424 }
425
426 return ret;
427 }
428
429 /**
430 * clkdm_del_wkdep - remove a wakeup dependency from clkdm2 to clkdm1
431 * @clkdm1: wake this struct clockdomain * up (dependent)
432 * @clkdm2: when this struct clockdomain * wakes up (source)
433 *
434 * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2
435 * wakes up. Returns -EINVAL if presented with invalid clockdomain
436 * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or
437 * 0 upon success.
438 */
clkdm_del_wkdep(struct clockdomain * clkdm1,struct clockdomain * clkdm2)439 int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
440 {
441 struct clkdm_dep *cd;
442 int ret = 0;
443
444 if (!clkdm1 || !clkdm2)
445 return -EINVAL;
446
447 cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
448 if (IS_ERR(cd))
449 ret = PTR_ERR(cd);
450
451 if (!arch_clkdm || !arch_clkdm->clkdm_del_wkdep)
452 ret = -EINVAL;
453
454 if (ret) {
455 pr_debug("clockdomain: hardware cannot set/clear wake up of "
456 "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
457 return ret;
458 }
459
460 if (atomic_dec_return(&cd->wkdep_usecount) == 0) {
461 pr_debug("clockdomain: hardware will no longer wake up %s "
462 "after %s wakes up\n", clkdm1->name, clkdm2->name);
463
464 ret = arch_clkdm->clkdm_del_wkdep(clkdm1, clkdm2);
465 }
466
467 return ret;
468 }
469
470 /**
471 * clkdm_read_wkdep - read wakeup dependency state from clkdm2 to clkdm1
472 * @clkdm1: wake this struct clockdomain * up (dependent)
473 * @clkdm2: when this struct clockdomain * wakes up (source)
474 *
475 * Return 1 if a hardware wakeup dependency exists wherein @clkdm1 will be
476 * awoken when @clkdm2 wakes up; 0 if dependency is not set; -EINVAL
477 * if either clockdomain pointer is invalid; or -ENOENT if the hardware
478 * is incapable.
479 *
480 * REVISIT: Currently this function only represents software-controllable
481 * wakeup dependencies. Wakeup dependencies fixed in hardware are not
482 * yet handled here.
483 */
clkdm_read_wkdep(struct clockdomain * clkdm1,struct clockdomain * clkdm2)484 int clkdm_read_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
485 {
486 struct clkdm_dep *cd;
487 int ret = 0;
488
489 if (!clkdm1 || !clkdm2)
490 return -EINVAL;
491
492 cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
493 if (IS_ERR(cd))
494 ret = PTR_ERR(cd);
495
496 if (!arch_clkdm || !arch_clkdm->clkdm_read_wkdep)
497 ret = -EINVAL;
498
499 if (ret) {
500 pr_debug("clockdomain: hardware cannot set/clear wake up of "
501 "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
502 return ret;
503 }
504
505 /* XXX It's faster to return the atomic wkdep_usecount */
506 return arch_clkdm->clkdm_read_wkdep(clkdm1, clkdm2);
507 }
508
509 /**
510 * clkdm_clear_all_wkdeps - remove all wakeup dependencies from target clkdm
511 * @clkdm: struct clockdomain * to remove all wakeup dependencies from
512 *
513 * Remove all inter-clockdomain wakeup dependencies that could cause
514 * @clkdm to wake. Intended to be used during boot to initialize the
515 * PRCM to a known state, after all clockdomains are put into swsup idle
516 * and woken up. Returns -EINVAL if @clkdm pointer is invalid, or
517 * 0 upon success.
518 */
clkdm_clear_all_wkdeps(struct clockdomain * clkdm)519 int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
520 {
521 if (!clkdm)
522 return -EINVAL;
523
524 if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_wkdeps)
525 return -EINVAL;
526
527 return arch_clkdm->clkdm_clear_all_wkdeps(clkdm);
528 }
529
530 /**
531 * clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1
532 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
533 * @clkdm2: when this struct clockdomain * is active (source)
534 *
535 * Prevent @clkdm1 from automatically going inactive (and then to
536 * retention or off) if @clkdm2 is active. Returns -EINVAL if
537 * presented with invalid clockdomain pointers or called on a machine
538 * that does not support software-configurable hardware sleep
539 * dependencies, -ENOENT if the specified dependency cannot be set in
540 * hardware, or 0 upon success.
541 */
clkdm_add_sleepdep(struct clockdomain * clkdm1,struct clockdomain * clkdm2)542 int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
543 {
544 struct clkdm_dep *cd;
545 int ret = 0;
546
547 if (!clkdm1 || !clkdm2)
548 return -EINVAL;
549
550 cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
551 if (IS_ERR(cd))
552 ret = PTR_ERR(cd);
553
554 if (!arch_clkdm || !arch_clkdm->clkdm_add_sleepdep)
555 ret = -EINVAL;
556
557 if (ret) {
558 pr_debug("clockdomain: hardware cannot set/clear sleep "
559 "dependency affecting %s from %s\n", clkdm1->name,
560 clkdm2->name);
561 return ret;
562 }
563
564 if (atomic_inc_return(&cd->sleepdep_usecount) == 1) {
565 pr_debug("clockdomain: will prevent %s from sleeping if %s "
566 "is active\n", clkdm1->name, clkdm2->name);
567
568 ret = arch_clkdm->clkdm_add_sleepdep(clkdm1, clkdm2);
569 }
570
571 return ret;
572 }
573
574 /**
575 * clkdm_del_sleepdep - remove a sleep dependency from clkdm2 to clkdm1
576 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
577 * @clkdm2: when this struct clockdomain * is active (source)
578 *
579 * Allow @clkdm1 to automatically go inactive (and then to retention or
580 * off), independent of the activity state of @clkdm2. Returns -EINVAL
581 * if presented with invalid clockdomain pointers or called on a machine
582 * that does not support software-configurable hardware sleep dependencies,
583 * -ENOENT if the specified dependency cannot be cleared in hardware, or
584 * 0 upon success.
585 */
clkdm_del_sleepdep(struct clockdomain * clkdm1,struct clockdomain * clkdm2)586 int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
587 {
588 struct clkdm_dep *cd;
589 int ret = 0;
590
591 if (!clkdm1 || !clkdm2)
592 return -EINVAL;
593
594 cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
595 if (IS_ERR(cd))
596 ret = PTR_ERR(cd);
597
598 if (!arch_clkdm || !arch_clkdm->clkdm_del_sleepdep)
599 ret = -EINVAL;
600
601 if (ret) {
602 pr_debug("clockdomain: hardware cannot set/clear sleep "
603 "dependency affecting %s from %s\n", clkdm1->name,
604 clkdm2->name);
605 return ret;
606 }
607
608 if (atomic_dec_return(&cd->sleepdep_usecount) == 0) {
609 pr_debug("clockdomain: will no longer prevent %s from "
610 "sleeping if %s is active\n", clkdm1->name,
611 clkdm2->name);
612
613 ret = arch_clkdm->clkdm_del_sleepdep(clkdm1, clkdm2);
614 }
615
616 return ret;
617 }
618
619 /**
620 * clkdm_read_sleepdep - read sleep dependency state from clkdm2 to clkdm1
621 * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
622 * @clkdm2: when this struct clockdomain * is active (source)
623 *
624 * Return 1 if a hardware sleep dependency exists wherein @clkdm1 will
625 * not be allowed to automatically go inactive if @clkdm2 is active;
626 * 0 if @clkdm1's automatic power state inactivity transition is independent
627 * of @clkdm2's; -EINVAL if either clockdomain pointer is invalid or called
628 * on a machine that does not support software-configurable hardware sleep
629 * dependencies; or -ENOENT if the hardware is incapable.
630 *
631 * REVISIT: Currently this function only represents software-controllable
632 * sleep dependencies. Sleep dependencies fixed in hardware are not
633 * yet handled here.
634 */
clkdm_read_sleepdep(struct clockdomain * clkdm1,struct clockdomain * clkdm2)635 int clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
636 {
637 struct clkdm_dep *cd;
638 int ret = 0;
639
640 if (!clkdm1 || !clkdm2)
641 return -EINVAL;
642
643 cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
644 if (IS_ERR(cd))
645 ret = PTR_ERR(cd);
646
647 if (!arch_clkdm || !arch_clkdm->clkdm_read_sleepdep)
648 ret = -EINVAL;
649
650 if (ret) {
651 pr_debug("clockdomain: hardware cannot set/clear sleep "
652 "dependency affecting %s from %s\n", clkdm1->name,
653 clkdm2->name);
654 return ret;
655 }
656
657 /* XXX It's faster to return the atomic sleepdep_usecount */
658 return arch_clkdm->clkdm_read_sleepdep(clkdm1, clkdm2);
659 }
660
661 /**
662 * clkdm_clear_all_sleepdeps - remove all sleep dependencies from target clkdm
663 * @clkdm: struct clockdomain * to remove all sleep dependencies from
664 *
665 * Remove all inter-clockdomain sleep dependencies that could prevent
666 * @clkdm from idling. Intended to be used during boot to initialize the
667 * PRCM to a known state, after all clockdomains are put into swsup idle
668 * and woken up. Returns -EINVAL if @clkdm pointer is invalid, or
669 * 0 upon success.
670 */
clkdm_clear_all_sleepdeps(struct clockdomain * clkdm)671 int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
672 {
673 if (!clkdm)
674 return -EINVAL;
675
676 if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_sleepdeps)
677 return -EINVAL;
678
679 return arch_clkdm->clkdm_clear_all_sleepdeps(clkdm);
680 }
681
682 /**
683 * clkdm_sleep - force clockdomain sleep transition
684 * @clkdm: struct clockdomain *
685 *
686 * Instruct the CM to force a sleep transition on the specified
687 * clockdomain @clkdm. Returns -EINVAL if @clkdm is NULL or if
688 * clockdomain does not support software-initiated sleep; 0 upon
689 * success.
690 */
clkdm_sleep(struct clockdomain * clkdm)691 int clkdm_sleep(struct clockdomain *clkdm)
692 {
693 if (!clkdm)
694 return -EINVAL;
695
696 if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) {
697 pr_debug("clockdomain: %s does not support forcing "
698 "sleep via software\n", clkdm->name);
699 return -EINVAL;
700 }
701
702 if (!arch_clkdm || !arch_clkdm->clkdm_sleep)
703 return -EINVAL;
704
705 pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
706
707 return arch_clkdm->clkdm_sleep(clkdm);
708 }
709
710 /**
711 * clkdm_wakeup - force clockdomain wakeup transition
712 * @clkdm: struct clockdomain *
713 *
714 * Instruct the CM to force a wakeup transition on the specified
715 * clockdomain @clkdm. Returns -EINVAL if @clkdm is NULL or if the
716 * clockdomain does not support software-controlled wakeup; 0 upon
717 * success.
718 */
clkdm_wakeup(struct clockdomain * clkdm)719 int clkdm_wakeup(struct clockdomain *clkdm)
720 {
721 if (!clkdm)
722 return -EINVAL;
723
724 if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) {
725 pr_debug("clockdomain: %s does not support forcing "
726 "wakeup via software\n", clkdm->name);
727 return -EINVAL;
728 }
729
730 if (!arch_clkdm || !arch_clkdm->clkdm_wakeup)
731 return -EINVAL;
732
733 pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
734
735 return arch_clkdm->clkdm_wakeup(clkdm);
736 }
737
738 /**
739 * clkdm_allow_idle - enable hwsup idle transitions for clkdm
740 * @clkdm: struct clockdomain *
741 *
742 * Allow the hardware to automatically switch the clockdomain @clkdm into
743 * active or idle states, as needed by downstream clocks. If the
744 * clockdomain has any downstream clocks enabled in the clock
745 * framework, wkdep/sleepdep autodependencies are added; this is so
746 * device drivers can read and write to the device. No return value.
747 */
clkdm_allow_idle(struct clockdomain * clkdm)748 void clkdm_allow_idle(struct clockdomain *clkdm)
749 {
750 if (!clkdm)
751 return;
752
753 if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO)) {
754 pr_debug("clock: automatic idle transitions cannot be enabled "
755 "on clockdomain %s\n", clkdm->name);
756 return;
757 }
758
759 if (!arch_clkdm || !arch_clkdm->clkdm_allow_idle)
760 return;
761
762 pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
763 clkdm->name);
764
765 arch_clkdm->clkdm_allow_idle(clkdm);
766 pwrdm_clkdm_state_switch(clkdm);
767 }
768
769 /**
770 * clkdm_deny_idle - disable hwsup idle transitions for clkdm
771 * @clkdm: struct clockdomain *
772 *
773 * Prevent the hardware from automatically switching the clockdomain
774 * @clkdm into inactive or idle states. If the clockdomain has
775 * downstream clocks enabled in the clock framework, wkdep/sleepdep
776 * autodependencies are removed. No return value.
777 */
clkdm_deny_idle(struct clockdomain * clkdm)778 void clkdm_deny_idle(struct clockdomain *clkdm)
779 {
780 if (!clkdm)
781 return;
782
783 if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO)) {
784 pr_debug("clockdomain: automatic idle transitions cannot be "
785 "disabled on %s\n", clkdm->name);
786 return;
787 }
788
789 if (!arch_clkdm || !arch_clkdm->clkdm_deny_idle)
790 return;
791
792 pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
793 clkdm->name);
794
795 arch_clkdm->clkdm_deny_idle(clkdm);
796 }
797
798
799 /* Clockdomain-to-clock framework interface code */
800
801 /**
802 * clkdm_clk_enable - add an enabled downstream clock to this clkdm
803 * @clkdm: struct clockdomain *
804 * @clk: struct clk * of the enabled downstream clock
805 *
806 * Increment the usecount of the clockdomain @clkdm and ensure that it
807 * is awake before @clk is enabled. Intended to be called by
808 * clk_enable() code. If the clockdomain is in software-supervised
809 * idle mode, force the clockdomain to wake. If the clockdomain is in
810 * hardware-supervised idle mode, add clkdm-pwrdm autodependencies, to
811 * ensure that devices in the clockdomain can be read from/written to
812 * by on-chip processors. Returns -EINVAL if passed null pointers;
813 * returns 0 upon success or if the clockdomain is in hwsup idle mode.
814 */
clkdm_clk_enable(struct clockdomain * clkdm,struct clk * clk)815 int clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
816 {
817 /*
818 * XXX Rewrite this code to maintain a list of enabled
819 * downstream clocks for debugging purposes?
820 */
821
822 if (!clkdm || !clk)
823 return -EINVAL;
824
825 if (!arch_clkdm || !arch_clkdm->clkdm_clk_enable)
826 return -EINVAL;
827
828 if (atomic_inc_return(&clkdm->usecount) > 1)
829 return 0;
830
831 /* Clockdomain now has one enabled downstream clock */
832
833 pr_debug("clockdomain: clkdm %s: clk %s now enabled\n", clkdm->name,
834 clk->name);
835
836 arch_clkdm->clkdm_clk_enable(clkdm);
837 pwrdm_wait_transition(clkdm->pwrdm.ptr);
838 pwrdm_clkdm_state_switch(clkdm);
839
840 return 0;
841 }
842
843 /**
844 * clkdm_clk_disable - remove an enabled downstream clock from this clkdm
845 * @clkdm: struct clockdomain *
846 * @clk: struct clk * of the disabled downstream clock
847 *
848 * Decrement the usecount of this clockdomain @clkdm when @clk is
849 * disabled. Intended to be called by clk_disable() code. If the
850 * clockdomain usecount goes to 0, put the clockdomain to sleep
851 * (software-supervised mode) or remove the clkdm autodependencies
852 * (hardware-supervised mode). Returns -EINVAL if passed null
853 * pointers; -ERANGE if the @clkdm usecount underflows and debugging
854 * is enabled; or returns 0 upon success or if the clockdomain is in
855 * hwsup idle mode.
856 */
clkdm_clk_disable(struct clockdomain * clkdm,struct clk * clk)857 int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
858 {
859 /*
860 * XXX Rewrite this code to maintain a list of enabled
861 * downstream clocks for debugging purposes?
862 */
863
864 if (!clkdm || !clk)
865 return -EINVAL;
866
867 if (!arch_clkdm || !arch_clkdm->clkdm_clk_disable)
868 return -EINVAL;
869
870 #ifdef DEBUG
871 if (atomic_read(&clkdm->usecount) == 0) {
872 WARN_ON(1); /* underflow */
873 return -ERANGE;
874 }
875 #endif
876
877 if (atomic_dec_return(&clkdm->usecount) > 0)
878 return 0;
879
880 /* All downstream clocks of this clockdomain are now disabled */
881
882 pr_debug("clockdomain: clkdm %s: clk %s now disabled\n", clkdm->name,
883 clk->name);
884
885 arch_clkdm->clkdm_clk_disable(clkdm);
886 pwrdm_clkdm_state_switch(clkdm);
887
888 return 0;
889 }
890
891