1 /*
2  * Copyright (C) 2014 Broadcom Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation version 2.
7  *
8  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9  * kind, whether express or implied; without even the implied warranty
10  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/err.h>
16 #include <linux/clk-provider.h>
17 #include <linux/io.h>
18 #include <linux/of.h>
19 #include <linux/clkdev.h>
20 #include <linux/of_address.h>
21 #include <linux/delay.h>
22 
23 #include "clk-iproc.h"
24 
25 #define PLL_VCO_HIGH_SHIFT 19
26 #define PLL_VCO_LOW_SHIFT  30
27 
28 /*
29  * PLL MACRO_SELECT modes 0 to 5 choose pre-calculated PLL output frequencies
30  * from a look-up table. Mode 7 allows user to manipulate PLL clock dividers
31  */
32 #define PLL_USER_MODE 7
33 
34 /* number of delay loops waiting for PLL to lock */
35 #define LOCK_DELAY 100
36 
37 /* number of VCO frequency bands */
38 #define NUM_FREQ_BANDS 8
39 
40 #define NUM_KP_BANDS 3
41 enum kp_band {
42 	KP_BAND_MID = 0,
43 	KP_BAND_HIGH,
44 	KP_BAND_HIGH_HIGH
45 };
46 
47 static const unsigned int kp_table[NUM_KP_BANDS][NUM_FREQ_BANDS] = {
48 	{ 5, 6, 6, 7, 7, 8, 9, 10 },
49 	{ 4, 4, 5, 5, 6, 7, 8, 9  },
50 	{ 4, 5, 5, 6, 7, 8, 9, 10 },
51 };
52 
53 static const unsigned long ref_freq_table[NUM_FREQ_BANDS][2] = {
54 	{ 10000000,  12500000  },
55 	{ 12500000,  15000000  },
56 	{ 15000000,  20000000  },
57 	{ 20000000,  25000000  },
58 	{ 25000000,  50000000  },
59 	{ 50000000,  75000000  },
60 	{ 75000000,  100000000 },
61 	{ 100000000, 125000000 },
62 };
63 
64 enum vco_freq_range {
65 	VCO_LOW       = 700000000U,
66 	VCO_MID       = 1200000000U,
67 	VCO_HIGH      = 2200000000U,
68 	VCO_HIGH_HIGH = 3100000000U,
69 	VCO_MAX       = 4000000000U,
70 };
71 
72 struct iproc_pll {
73 	void __iomem *status_base;
74 	void __iomem *control_base;
75 	void __iomem *pwr_base;
76 	void __iomem *asiu_base;
77 
78 	const struct iproc_pll_ctrl *ctrl;
79 	const struct iproc_pll_vco_param *vco_param;
80 	unsigned int num_vco_entries;
81 };
82 
83 struct iproc_clk {
84 	struct clk_hw hw;
85 	struct iproc_pll *pll;
86 	const struct iproc_clk_ctrl *ctrl;
87 };
88 
89 #define to_iproc_clk(hw) container_of(hw, struct iproc_clk, hw)
90 
pll_calc_param(unsigned long target_rate,unsigned long parent_rate,struct iproc_pll_vco_param * vco_out)91 static int pll_calc_param(unsigned long target_rate,
92 			unsigned long parent_rate,
93 			struct iproc_pll_vco_param *vco_out)
94 {
95 	u64 ndiv_int, ndiv_frac, residual;
96 
97 	ndiv_int = target_rate / parent_rate;
98 
99 	if (!ndiv_int || (ndiv_int > 255))
100 		return -EINVAL;
101 
102 	residual = target_rate - (ndiv_int * parent_rate);
103 	residual <<= 20;
104 
105 	/*
106 	 * Add half of the divisor so the result will be rounded to closest
107 	 * instead of rounded down.
108 	 */
109 	residual += (parent_rate / 2);
110 	ndiv_frac = div64_u64((u64)residual, (u64)parent_rate);
111 
112 	vco_out->ndiv_int = ndiv_int;
113 	vco_out->ndiv_frac = ndiv_frac;
114 	vco_out->pdiv = 1;
115 
116 	vco_out->rate = vco_out->ndiv_int * parent_rate;
117 	residual = (u64)vco_out->ndiv_frac * (u64)parent_rate;
118 	residual >>= 20;
119 	vco_out->rate += residual;
120 
121 	return 0;
122 }
123 
124 /*
125  * Based on the target frequency, find a match from the VCO frequency parameter
126  * table and return its index
127  */
pll_get_rate_index(struct iproc_pll * pll,unsigned int target_rate)128 static int pll_get_rate_index(struct iproc_pll *pll, unsigned int target_rate)
129 {
130 	int i;
131 
132 	for (i = 0; i < pll->num_vco_entries; i++)
133 		if (target_rate == pll->vco_param[i].rate)
134 			break;
135 
136 	if (i >= pll->num_vco_entries)
137 		return -EINVAL;
138 
139 	return i;
140 }
141 
get_kp(unsigned long ref_freq,enum kp_band kp_index)142 static int get_kp(unsigned long ref_freq, enum kp_band kp_index)
143 {
144 	int i;
145 
146 	if (ref_freq < ref_freq_table[0][0])
147 		return -EINVAL;
148 
149 	for (i = 0; i < NUM_FREQ_BANDS; i++) {
150 		if (ref_freq >= ref_freq_table[i][0] &&
151 		    ref_freq < ref_freq_table[i][1])
152 			return kp_table[kp_index][i];
153 	}
154 	return -EINVAL;
155 }
156 
pll_wait_for_lock(struct iproc_pll * pll)157 static int pll_wait_for_lock(struct iproc_pll *pll)
158 {
159 	int i;
160 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
161 
162 	for (i = 0; i < LOCK_DELAY; i++) {
163 		u32 val = readl(pll->status_base + ctrl->status.offset);
164 
165 		if (val & (1 << ctrl->status.shift))
166 			return 0;
167 		udelay(10);
168 	}
169 
170 	return -EIO;
171 }
172 
iproc_pll_write(const struct iproc_pll * pll,void __iomem * base,const u32 offset,u32 val)173 static void iproc_pll_write(const struct iproc_pll *pll, void __iomem *base,
174 			    const u32 offset, u32 val)
175 {
176 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
177 
178 	writel(val, base + offset);
179 
180 	if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK &&
181 		     (base == pll->status_base || base == pll->control_base)))
182 		val = readl(base + offset);
183 }
184 
__pll_disable(struct iproc_pll * pll)185 static void __pll_disable(struct iproc_pll *pll)
186 {
187 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
188 	u32 val;
189 
190 	if (ctrl->flags & IPROC_CLK_PLL_ASIU) {
191 		val = readl(pll->asiu_base + ctrl->asiu.offset);
192 		val &= ~(1 << ctrl->asiu.en_shift);
193 		iproc_pll_write(pll, pll->asiu_base, ctrl->asiu.offset, val);
194 	}
195 
196 	if (ctrl->flags & IPROC_CLK_EMBED_PWRCTRL) {
197 		val = readl(pll->control_base + ctrl->aon.offset);
198 		val |= bit_mask(ctrl->aon.pwr_width) << ctrl->aon.pwr_shift;
199 		iproc_pll_write(pll, pll->control_base, ctrl->aon.offset, val);
200 	}
201 
202 	if (pll->pwr_base) {
203 		/* latch input value so core power can be shut down */
204 		val = readl(pll->pwr_base + ctrl->aon.offset);
205 		val |= 1 << ctrl->aon.iso_shift;
206 		iproc_pll_write(pll, pll->pwr_base, ctrl->aon.offset, val);
207 
208 		/* power down the core */
209 		val &= ~(bit_mask(ctrl->aon.pwr_width) << ctrl->aon.pwr_shift);
210 		iproc_pll_write(pll, pll->pwr_base, ctrl->aon.offset, val);
211 	}
212 }
213 
__pll_enable(struct iproc_pll * pll)214 static int __pll_enable(struct iproc_pll *pll)
215 {
216 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
217 	u32 val;
218 
219 	if (ctrl->flags & IPROC_CLK_EMBED_PWRCTRL) {
220 		val = readl(pll->control_base + ctrl->aon.offset);
221 		val &= ~(bit_mask(ctrl->aon.pwr_width) << ctrl->aon.pwr_shift);
222 		iproc_pll_write(pll, pll->control_base, ctrl->aon.offset, val);
223 	}
224 
225 	if (pll->pwr_base) {
226 		/* power up the PLL and make sure it's not latched */
227 		val = readl(pll->pwr_base + ctrl->aon.offset);
228 		val |= bit_mask(ctrl->aon.pwr_width) << ctrl->aon.pwr_shift;
229 		val &= ~(1 << ctrl->aon.iso_shift);
230 		iproc_pll_write(pll, pll->pwr_base, ctrl->aon.offset, val);
231 	}
232 
233 	/* certain PLLs also need to be ungated from the ASIU top level */
234 	if (ctrl->flags & IPROC_CLK_PLL_ASIU) {
235 		val = readl(pll->asiu_base + ctrl->asiu.offset);
236 		val |= (1 << ctrl->asiu.en_shift);
237 		iproc_pll_write(pll, pll->asiu_base, ctrl->asiu.offset, val);
238 	}
239 
240 	return 0;
241 }
242 
__pll_put_in_reset(struct iproc_pll * pll)243 static void __pll_put_in_reset(struct iproc_pll *pll)
244 {
245 	u32 val;
246 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
247 	const struct iproc_pll_reset_ctrl *reset = &ctrl->reset;
248 
249 	val = readl(pll->control_base + reset->offset);
250 	if (ctrl->flags & IPROC_CLK_PLL_RESET_ACTIVE_LOW)
251 		val |= BIT(reset->reset_shift) | BIT(reset->p_reset_shift);
252 	else
253 		val &= ~(BIT(reset->reset_shift) | BIT(reset->p_reset_shift));
254 	iproc_pll_write(pll, pll->control_base, reset->offset, val);
255 }
256 
__pll_bring_out_reset(struct iproc_pll * pll,unsigned int kp,unsigned int ka,unsigned int ki)257 static void __pll_bring_out_reset(struct iproc_pll *pll, unsigned int kp,
258 				  unsigned int ka, unsigned int ki)
259 {
260 	u32 val;
261 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
262 	const struct iproc_pll_reset_ctrl *reset = &ctrl->reset;
263 	const struct iproc_pll_dig_filter_ctrl *dig_filter = &ctrl->dig_filter;
264 
265 	val = readl(pll->control_base + dig_filter->offset);
266 	val &= ~(bit_mask(dig_filter->ki_width) << dig_filter->ki_shift |
267 		bit_mask(dig_filter->kp_width) << dig_filter->kp_shift |
268 		bit_mask(dig_filter->ka_width) << dig_filter->ka_shift);
269 	val |= ki << dig_filter->ki_shift | kp << dig_filter->kp_shift |
270 	       ka << dig_filter->ka_shift;
271 	iproc_pll_write(pll, pll->control_base, dig_filter->offset, val);
272 
273 	val = readl(pll->control_base + reset->offset);
274 	if (ctrl->flags & IPROC_CLK_PLL_RESET_ACTIVE_LOW)
275 		val &= ~(BIT(reset->reset_shift) | BIT(reset->p_reset_shift));
276 	else
277 		val |= BIT(reset->reset_shift) | BIT(reset->p_reset_shift);
278 	iproc_pll_write(pll, pll->control_base, reset->offset, val);
279 }
280 
281 /*
282  * Determines if the change to be applied to the PLL is minor (just an update
283  * or the fractional divider). If so, then we can avoid going through a
284  * disruptive reset and lock sequence.
285  */
pll_fractional_change_only(struct iproc_pll * pll,struct iproc_pll_vco_param * vco)286 static bool pll_fractional_change_only(struct iproc_pll *pll,
287 				       struct iproc_pll_vco_param *vco)
288 {
289 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
290 	u32 val;
291 	u32 ndiv_int;
292 	unsigned int pdiv;
293 
294 	/* PLL needs to be locked */
295 	val = readl(pll->status_base + ctrl->status.offset);
296 	if ((val & (1 << ctrl->status.shift)) == 0)
297 		return false;
298 
299 	val = readl(pll->control_base + ctrl->ndiv_int.offset);
300 	ndiv_int = (val >> ctrl->ndiv_int.shift) &
301 		bit_mask(ctrl->ndiv_int.width);
302 
303 	if (ndiv_int != vco->ndiv_int)
304 		return false;
305 
306 	val = readl(pll->control_base + ctrl->pdiv.offset);
307 	pdiv = (val >> ctrl->pdiv.shift) & bit_mask(ctrl->pdiv.width);
308 
309 	if (pdiv != vco->pdiv)
310 		return false;
311 
312 	return true;
313 }
314 
pll_set_rate(struct iproc_clk * clk,struct iproc_pll_vco_param * vco,unsigned long parent_rate)315 static int pll_set_rate(struct iproc_clk *clk, struct iproc_pll_vco_param *vco,
316 			unsigned long parent_rate)
317 {
318 	struct iproc_pll *pll = clk->pll;
319 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
320 	int ka = 0, ki, kp, ret;
321 	unsigned long rate = vco->rate;
322 	u32 val;
323 	enum kp_band kp_index;
324 	unsigned long ref_freq;
325 	const char *clk_name = clk_hw_get_name(&clk->hw);
326 
327 	/*
328 	 * reference frequency = parent frequency / PDIV
329 	 * If PDIV = 0, then it becomes a multiplier (x2)
330 	 */
331 	if (vco->pdiv == 0)
332 		ref_freq = parent_rate * 2;
333 	else
334 		ref_freq = parent_rate / vco->pdiv;
335 
336 	/* determine Ki and Kp index based on target VCO frequency */
337 	if (rate >= VCO_LOW && rate < VCO_HIGH) {
338 		ki = 4;
339 		kp_index = KP_BAND_MID;
340 	} else if (rate >= VCO_HIGH && rate < VCO_HIGH_HIGH) {
341 		ki = 3;
342 		kp_index = KP_BAND_HIGH;
343 	} else if (rate >= VCO_HIGH_HIGH && rate < VCO_MAX) {
344 		ki = 3;
345 		kp_index = KP_BAND_HIGH_HIGH;
346 	} else {
347 		pr_err("%s: pll: %s has invalid rate: %lu\n", __func__,
348 				clk_name, rate);
349 		return -EINVAL;
350 	}
351 
352 	kp = get_kp(ref_freq, kp_index);
353 	if (kp < 0) {
354 		pr_err("%s: pll: %s has invalid kp\n", __func__, clk_name);
355 		return kp;
356 	}
357 
358 	ret = __pll_enable(pll);
359 	if (ret) {
360 		pr_err("%s: pll: %s fails to enable\n", __func__, clk_name);
361 		return ret;
362 	}
363 
364 	if (pll_fractional_change_only(clk->pll, vco)) {
365 		/* program fractional part of NDIV */
366 		if (ctrl->flags & IPROC_CLK_PLL_HAS_NDIV_FRAC) {
367 			val = readl(pll->control_base + ctrl->ndiv_frac.offset);
368 			val &= ~(bit_mask(ctrl->ndiv_frac.width) <<
369 				 ctrl->ndiv_frac.shift);
370 			val |= vco->ndiv_frac << ctrl->ndiv_frac.shift;
371 			iproc_pll_write(pll, pll->control_base,
372 					ctrl->ndiv_frac.offset, val);
373 			return 0;
374 		}
375 	}
376 
377 	/* put PLL in reset */
378 	__pll_put_in_reset(pll);
379 
380 	/* set PLL in user mode before modifying PLL controls */
381 	if (ctrl->flags & IPROC_CLK_PLL_USER_MODE_ON) {
382 		val = readl(pll->control_base + ctrl->macro_mode.offset);
383 		val &= ~(bit_mask(ctrl->macro_mode.width) <<
384 			ctrl->macro_mode.shift);
385 		val |= PLL_USER_MODE << ctrl->macro_mode.shift;
386 		iproc_pll_write(pll, pll->control_base,
387 			ctrl->macro_mode.offset, val);
388 	}
389 
390 	iproc_pll_write(pll, pll->control_base, ctrl->vco_ctrl.u_offset, 0);
391 
392 	val = readl(pll->control_base + ctrl->vco_ctrl.l_offset);
393 
394 	if (rate >= VCO_LOW && rate < VCO_MID)
395 		val |= (1 << PLL_VCO_LOW_SHIFT);
396 
397 	if (rate < VCO_HIGH)
398 		val &= ~(1 << PLL_VCO_HIGH_SHIFT);
399 	else
400 		val |= (1 << PLL_VCO_HIGH_SHIFT);
401 
402 	iproc_pll_write(pll, pll->control_base, ctrl->vco_ctrl.l_offset, val);
403 
404 	/* program integer part of NDIV */
405 	val = readl(pll->control_base + ctrl->ndiv_int.offset);
406 	val &= ~(bit_mask(ctrl->ndiv_int.width) << ctrl->ndiv_int.shift);
407 	val |= vco->ndiv_int << ctrl->ndiv_int.shift;
408 	iproc_pll_write(pll, pll->control_base, ctrl->ndiv_int.offset, val);
409 
410 	/* program fractional part of NDIV */
411 	if (ctrl->flags & IPROC_CLK_PLL_HAS_NDIV_FRAC) {
412 		val = readl(pll->control_base + ctrl->ndiv_frac.offset);
413 		val &= ~(bit_mask(ctrl->ndiv_frac.width) <<
414 			 ctrl->ndiv_frac.shift);
415 		val |= vco->ndiv_frac << ctrl->ndiv_frac.shift;
416 		iproc_pll_write(pll, pll->control_base, ctrl->ndiv_frac.offset,
417 				val);
418 	}
419 
420 	/* program PDIV */
421 	val = readl(pll->control_base + ctrl->pdiv.offset);
422 	val &= ~(bit_mask(ctrl->pdiv.width) << ctrl->pdiv.shift);
423 	val |= vco->pdiv << ctrl->pdiv.shift;
424 	iproc_pll_write(pll, pll->control_base, ctrl->pdiv.offset, val);
425 
426 	__pll_bring_out_reset(pll, kp, ka, ki);
427 
428 	ret = pll_wait_for_lock(pll);
429 	if (ret < 0) {
430 		pr_err("%s: pll: %s failed to lock\n", __func__, clk_name);
431 		return ret;
432 	}
433 
434 	return 0;
435 }
436 
iproc_pll_enable(struct clk_hw * hw)437 static int iproc_pll_enable(struct clk_hw *hw)
438 {
439 	struct iproc_clk *clk = to_iproc_clk(hw);
440 	struct iproc_pll *pll = clk->pll;
441 
442 	return __pll_enable(pll);
443 }
444 
iproc_pll_disable(struct clk_hw * hw)445 static void iproc_pll_disable(struct clk_hw *hw)
446 {
447 	struct iproc_clk *clk = to_iproc_clk(hw);
448 	struct iproc_pll *pll = clk->pll;
449 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
450 
451 	if (ctrl->flags & IPROC_CLK_AON)
452 		return;
453 
454 	__pll_disable(pll);
455 }
456 
iproc_pll_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)457 static unsigned long iproc_pll_recalc_rate(struct clk_hw *hw,
458 					   unsigned long parent_rate)
459 {
460 	struct iproc_clk *clk = to_iproc_clk(hw);
461 	struct iproc_pll *pll = clk->pll;
462 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
463 	u32 val;
464 	u64 ndiv, ndiv_int, ndiv_frac;
465 	unsigned int pdiv;
466 	unsigned long rate;
467 
468 	if (parent_rate == 0)
469 		return 0;
470 
471 	/* PLL needs to be locked */
472 	val = readl(pll->status_base + ctrl->status.offset);
473 	if ((val & (1 << ctrl->status.shift)) == 0)
474 		return 0;
475 
476 	/*
477 	 * PLL output frequency =
478 	 *
479 	 * ((ndiv_int + ndiv_frac / 2^20) * (parent clock rate / pdiv)
480 	 */
481 	val = readl(pll->control_base + ctrl->ndiv_int.offset);
482 	ndiv_int = (val >> ctrl->ndiv_int.shift) &
483 		bit_mask(ctrl->ndiv_int.width);
484 	ndiv = ndiv_int << 20;
485 
486 	if (ctrl->flags & IPROC_CLK_PLL_HAS_NDIV_FRAC) {
487 		val = readl(pll->control_base + ctrl->ndiv_frac.offset);
488 		ndiv_frac = (val >> ctrl->ndiv_frac.shift) &
489 			bit_mask(ctrl->ndiv_frac.width);
490 		ndiv += ndiv_frac;
491 	}
492 
493 	val = readl(pll->control_base + ctrl->pdiv.offset);
494 	pdiv = (val >> ctrl->pdiv.shift) & bit_mask(ctrl->pdiv.width);
495 
496 	rate = (ndiv * parent_rate) >> 20;
497 
498 	if (pdiv == 0)
499 		rate *= 2;
500 	else
501 		rate /= pdiv;
502 
503 	return rate;
504 }
505 
iproc_pll_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)506 static int iproc_pll_determine_rate(struct clk_hw *hw,
507 		struct clk_rate_request *req)
508 {
509 	unsigned int  i;
510 	struct iproc_clk *clk = to_iproc_clk(hw);
511 	struct iproc_pll *pll = clk->pll;
512 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
513 	unsigned long  diff, best_diff;
514 	unsigned int  best_idx = 0;
515 	int ret;
516 
517 	if (req->rate == 0 || req->best_parent_rate == 0)
518 		return -EINVAL;
519 
520 	if (ctrl->flags & IPROC_CLK_PLL_CALC_PARAM) {
521 		struct iproc_pll_vco_param vco_param;
522 
523 		ret = pll_calc_param(req->rate, req->best_parent_rate,
524 					&vco_param);
525 		if (ret)
526 			return ret;
527 
528 		req->rate = vco_param.rate;
529 		return 0;
530 	}
531 
532 	if (!pll->vco_param)
533 		return -EINVAL;
534 
535 	best_diff = ULONG_MAX;
536 	for (i = 0; i < pll->num_vco_entries; i++) {
537 		diff = abs(req->rate - pll->vco_param[i].rate);
538 		if (diff <= best_diff) {
539 			best_diff = diff;
540 			best_idx = i;
541 		}
542 		/* break now if perfect match */
543 		if (diff == 0)
544 			break;
545 	}
546 
547 	req->rate = pll->vco_param[best_idx].rate;
548 
549 	return 0;
550 }
551 
iproc_pll_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)552 static int iproc_pll_set_rate(struct clk_hw *hw, unsigned long rate,
553 		unsigned long parent_rate)
554 {
555 	struct iproc_clk *clk = to_iproc_clk(hw);
556 	struct iproc_pll *pll = clk->pll;
557 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
558 	struct iproc_pll_vco_param vco_param;
559 	int rate_index, ret;
560 
561 	if (ctrl->flags & IPROC_CLK_PLL_CALC_PARAM) {
562 		ret = pll_calc_param(rate, parent_rate, &vco_param);
563 		if (ret)
564 			return ret;
565 	} else {
566 		rate_index = pll_get_rate_index(pll, rate);
567 		if (rate_index < 0)
568 			return rate_index;
569 
570 		vco_param = pll->vco_param[rate_index];
571 	}
572 
573 	ret = pll_set_rate(clk, &vco_param, parent_rate);
574 	return ret;
575 }
576 
577 static const struct clk_ops iproc_pll_ops = {
578 	.enable = iproc_pll_enable,
579 	.disable = iproc_pll_disable,
580 	.recalc_rate = iproc_pll_recalc_rate,
581 	.determine_rate = iproc_pll_determine_rate,
582 	.set_rate = iproc_pll_set_rate,
583 };
584 
iproc_clk_enable(struct clk_hw * hw)585 static int iproc_clk_enable(struct clk_hw *hw)
586 {
587 	struct iproc_clk *clk = to_iproc_clk(hw);
588 	const struct iproc_clk_ctrl *ctrl = clk->ctrl;
589 	struct iproc_pll *pll = clk->pll;
590 	u32 val;
591 
592 	/* channel enable is active low */
593 	val = readl(pll->control_base + ctrl->enable.offset);
594 	val &= ~(1 << ctrl->enable.enable_shift);
595 	iproc_pll_write(pll, pll->control_base, ctrl->enable.offset, val);
596 
597 	/* also make sure channel is not held */
598 	val = readl(pll->control_base + ctrl->enable.offset);
599 	val &= ~(1 << ctrl->enable.hold_shift);
600 	iproc_pll_write(pll, pll->control_base, ctrl->enable.offset, val);
601 
602 	return 0;
603 }
604 
iproc_clk_disable(struct clk_hw * hw)605 static void iproc_clk_disable(struct clk_hw *hw)
606 {
607 	struct iproc_clk *clk = to_iproc_clk(hw);
608 	const struct iproc_clk_ctrl *ctrl = clk->ctrl;
609 	struct iproc_pll *pll = clk->pll;
610 	u32 val;
611 
612 	if (ctrl->flags & IPROC_CLK_AON)
613 		return;
614 
615 	val = readl(pll->control_base + ctrl->enable.offset);
616 	val |= 1 << ctrl->enable.enable_shift;
617 	iproc_pll_write(pll, pll->control_base, ctrl->enable.offset, val);
618 }
619 
iproc_clk_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)620 static unsigned long iproc_clk_recalc_rate(struct clk_hw *hw,
621 		unsigned long parent_rate)
622 {
623 	struct iproc_clk *clk = to_iproc_clk(hw);
624 	const struct iproc_clk_ctrl *ctrl = clk->ctrl;
625 	struct iproc_pll *pll = clk->pll;
626 	u32 val;
627 	unsigned int mdiv;
628 	unsigned long rate;
629 
630 	if (parent_rate == 0)
631 		return 0;
632 
633 	val = readl(pll->control_base + ctrl->mdiv.offset);
634 	mdiv = (val >> ctrl->mdiv.shift) & bit_mask(ctrl->mdiv.width);
635 	if (mdiv == 0)
636 		mdiv = 256;
637 
638 	if (ctrl->flags & IPROC_CLK_MCLK_DIV_BY_2)
639 		rate = parent_rate / (mdiv * 2);
640 	else
641 		rate = parent_rate / mdiv;
642 
643 	return rate;
644 }
645 
iproc_clk_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)646 static int iproc_clk_determine_rate(struct clk_hw *hw,
647 		struct clk_rate_request *req)
648 {
649 	unsigned int bestdiv;
650 
651 	if (req->rate == 0)
652 		return -EINVAL;
653 	if (req->rate == req->best_parent_rate)
654 		return 0;
655 
656 	bestdiv = DIV_ROUND_CLOSEST(req->best_parent_rate, req->rate);
657 	if (bestdiv < 2)
658 		req->rate = req->best_parent_rate;
659 
660 	if (bestdiv > 256)
661 		bestdiv = 256;
662 
663 	req->rate = req->best_parent_rate / bestdiv;
664 
665 	return 0;
666 }
667 
iproc_clk_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)668 static int iproc_clk_set_rate(struct clk_hw *hw, unsigned long rate,
669 		unsigned long parent_rate)
670 {
671 	struct iproc_clk *clk = to_iproc_clk(hw);
672 	const struct iproc_clk_ctrl *ctrl = clk->ctrl;
673 	struct iproc_pll *pll = clk->pll;
674 	u32 val;
675 	unsigned int div;
676 
677 	if (rate == 0 || parent_rate == 0)
678 		return -EINVAL;
679 
680 	div = DIV_ROUND_CLOSEST(parent_rate, rate);
681 	if (ctrl->flags & IPROC_CLK_MCLK_DIV_BY_2)
682 		div /=  2;
683 
684 	if (div > 256)
685 		return -EINVAL;
686 
687 	val = readl(pll->control_base + ctrl->mdiv.offset);
688 	if (div == 256) {
689 		val &= ~(bit_mask(ctrl->mdiv.width) << ctrl->mdiv.shift);
690 	} else {
691 		val &= ~(bit_mask(ctrl->mdiv.width) << ctrl->mdiv.shift);
692 		val |= div << ctrl->mdiv.shift;
693 	}
694 	iproc_pll_write(pll, pll->control_base, ctrl->mdiv.offset, val);
695 
696 	return 0;
697 }
698 
699 static const struct clk_ops iproc_clk_ops = {
700 	.enable = iproc_clk_enable,
701 	.disable = iproc_clk_disable,
702 	.recalc_rate = iproc_clk_recalc_rate,
703 	.determine_rate = iproc_clk_determine_rate,
704 	.set_rate = iproc_clk_set_rate,
705 };
706 
707 /*
708  * Some PLLs require the PLL SW override bit to be set before changes can be
709  * applied to the PLL
710  */
iproc_pll_sw_cfg(struct iproc_pll * pll)711 static void iproc_pll_sw_cfg(struct iproc_pll *pll)
712 {
713 	const struct iproc_pll_ctrl *ctrl = pll->ctrl;
714 
715 	if (ctrl->flags & IPROC_CLK_PLL_NEEDS_SW_CFG) {
716 		u32 val;
717 
718 		val = readl(pll->control_base + ctrl->sw_ctrl.offset);
719 		val |= BIT(ctrl->sw_ctrl.shift);
720 		iproc_pll_write(pll, pll->control_base, ctrl->sw_ctrl.offset,
721 				val);
722 	}
723 }
724 
iproc_pll_clk_setup(struct device_node * node,const struct iproc_pll_ctrl * pll_ctrl,const struct iproc_pll_vco_param * vco,unsigned int num_vco_entries,const struct iproc_clk_ctrl * clk_ctrl,unsigned int num_clks)725 void iproc_pll_clk_setup(struct device_node *node,
726 			 const struct iproc_pll_ctrl *pll_ctrl,
727 			 const struct iproc_pll_vco_param *vco,
728 			 unsigned int num_vco_entries,
729 			 const struct iproc_clk_ctrl *clk_ctrl,
730 			 unsigned int num_clks)
731 {
732 	int i, ret;
733 	struct iproc_pll *pll;
734 	struct iproc_clk *iclk;
735 	struct clk_init_data init;
736 	const char *parent_name;
737 	struct iproc_clk *iclk_array;
738 	struct clk_hw_onecell_data *clk_data;
739 
740 	if (WARN_ON(!pll_ctrl) || WARN_ON(!clk_ctrl))
741 		return;
742 
743 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
744 	if (WARN_ON(!pll))
745 		return;
746 
747 	clk_data = kzalloc(struct_size(clk_data, hws, num_clks), GFP_KERNEL);
748 	if (WARN_ON(!clk_data))
749 		goto err_clk_data;
750 	clk_data->num = num_clks;
751 
752 	iclk_array = kcalloc(num_clks, sizeof(struct iproc_clk), GFP_KERNEL);
753 	if (WARN_ON(!iclk_array))
754 		goto err_clks;
755 
756 	pll->control_base = of_iomap(node, 0);
757 	if (WARN_ON(!pll->control_base))
758 		goto err_pll_iomap;
759 
760 	/* Some SoCs do not require the pwr_base, thus failing is not fatal */
761 	pll->pwr_base = of_iomap(node, 1);
762 
763 	/* some PLLs require gating control at the top ASIU level */
764 	if (pll_ctrl->flags & IPROC_CLK_PLL_ASIU) {
765 		pll->asiu_base = of_iomap(node, 2);
766 		if (WARN_ON(!pll->asiu_base))
767 			goto err_asiu_iomap;
768 	}
769 
770 	if (pll_ctrl->flags & IPROC_CLK_PLL_SPLIT_STAT_CTRL) {
771 		/* Some SoCs have a split status/control.  If this does not
772 		 * exist, assume they are unified.
773 		 */
774 		pll->status_base = of_iomap(node, 2);
775 		if (!pll->status_base)
776 			goto err_status_iomap;
777 	} else
778 		pll->status_base = pll->control_base;
779 
780 	/* initialize and register the PLL itself */
781 	pll->ctrl = pll_ctrl;
782 
783 	iclk = &iclk_array[0];
784 	iclk->pll = pll;
785 
786 	init.name = node->name;
787 	init.ops = &iproc_pll_ops;
788 	init.flags = 0;
789 	parent_name = of_clk_get_parent_name(node, 0);
790 	init.parent_names = (parent_name ? &parent_name : NULL);
791 	init.num_parents = (parent_name ? 1 : 0);
792 	iclk->hw.init = &init;
793 
794 	if (vco) {
795 		pll->num_vco_entries = num_vco_entries;
796 		pll->vco_param = vco;
797 	}
798 
799 	iproc_pll_sw_cfg(pll);
800 
801 	ret = clk_hw_register(NULL, &iclk->hw);
802 	if (WARN_ON(ret))
803 		goto err_pll_register;
804 
805 	clk_data->hws[0] = &iclk->hw;
806 
807 	/* now initialize and register all leaf clocks */
808 	for (i = 1; i < num_clks; i++) {
809 		const char *clk_name;
810 
811 		memset(&init, 0, sizeof(init));
812 		parent_name = node->name;
813 
814 		ret = of_property_read_string_index(node, "clock-output-names",
815 						    i, &clk_name);
816 		if (WARN_ON(ret))
817 			goto err_clk_register;
818 
819 		iclk = &iclk_array[i];
820 		iclk->pll = pll;
821 		iclk->ctrl = &clk_ctrl[i];
822 
823 		init.name = clk_name;
824 		init.ops = &iproc_clk_ops;
825 		init.flags = 0;
826 		init.parent_names = (parent_name ? &parent_name : NULL);
827 		init.num_parents = (parent_name ? 1 : 0);
828 		iclk->hw.init = &init;
829 
830 		ret = clk_hw_register(NULL, &iclk->hw);
831 		if (WARN_ON(ret))
832 			goto err_clk_register;
833 
834 		clk_data->hws[i] = &iclk->hw;
835 	}
836 
837 	ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
838 	if (WARN_ON(ret))
839 		goto err_clk_register;
840 
841 	return;
842 
843 err_clk_register:
844 	while (--i >= 0)
845 		clk_hw_unregister(clk_data->hws[i]);
846 
847 err_pll_register:
848 	if (pll->status_base != pll->control_base)
849 		iounmap(pll->status_base);
850 
851 err_status_iomap:
852 	if (pll->asiu_base)
853 		iounmap(pll->asiu_base);
854 
855 err_asiu_iomap:
856 	if (pll->pwr_base)
857 		iounmap(pll->pwr_base);
858 
859 	iounmap(pll->control_base);
860 
861 err_pll_iomap:
862 	kfree(iclk_array);
863 
864 err_clks:
865 	kfree(clk_data);
866 
867 err_clk_data:
868 	kfree(pll);
869 }
870