xref: /linux/drivers/clk/at91/clk-master.c (revision c5538816)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
4  */
5 
6 #include <linux/clk-provider.h>
7 #include <linux/clkdev.h>
8 #include <linux/clk/at91_pmc.h>
9 #include <linux/of.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/regmap.h>
12 
13 #include "pmc.h"
14 
15 #define MASTER_PRES_MASK	0x7
16 #define MASTER_PRES_MAX		MASTER_PRES_MASK
17 #define MASTER_DIV_SHIFT	8
18 #define MASTER_DIV_MASK		0x7
19 
20 #define PMC_MCR_CSS_SHIFT	(16)
21 
22 #define MASTER_MAX_ID		4
23 
24 #define to_clk_master(hw) container_of(hw, struct clk_master, hw)
25 
26 struct clk_master {
27 	struct clk_hw hw;
28 	struct regmap *regmap;
29 	spinlock_t *lock;
30 	const struct clk_master_layout *layout;
31 	const struct clk_master_characteristics *characteristics;
32 	struct at91_clk_pms pms;
33 	u32 *mux_table;
34 	u32 mckr;
35 	int chg_pid;
36 	u8 id;
37 	u8 parent;
38 	u8 div;
39 };
40 
41 static inline bool clk_master_ready(struct clk_master *master)
42 {
43 	unsigned int bit = master->id ? AT91_PMC_MCKXRDY : AT91_PMC_MCKRDY;
44 	unsigned int status;
45 
46 	regmap_read(master->regmap, AT91_PMC_SR, &status);
47 
48 	return !!(status & bit);
49 }
50 
51 static int clk_master_prepare(struct clk_hw *hw)
52 {
53 	struct clk_master *master = to_clk_master(hw);
54 	unsigned long flags;
55 
56 	spin_lock_irqsave(master->lock, flags);
57 
58 	while (!clk_master_ready(master))
59 		cpu_relax();
60 
61 	spin_unlock_irqrestore(master->lock, flags);
62 
63 	return 0;
64 }
65 
66 static int clk_master_is_prepared(struct clk_hw *hw)
67 {
68 	struct clk_master *master = to_clk_master(hw);
69 	unsigned long flags;
70 	bool status;
71 
72 	spin_lock_irqsave(master->lock, flags);
73 	status = clk_master_ready(master);
74 	spin_unlock_irqrestore(master->lock, flags);
75 
76 	return status;
77 }
78 
79 static unsigned long clk_master_div_recalc_rate(struct clk_hw *hw,
80 						unsigned long parent_rate)
81 {
82 	u8 div;
83 	unsigned long flags, rate = parent_rate;
84 	struct clk_master *master = to_clk_master(hw);
85 	const struct clk_master_layout *layout = master->layout;
86 	const struct clk_master_characteristics *characteristics =
87 						master->characteristics;
88 	unsigned int mckr;
89 
90 	spin_lock_irqsave(master->lock, flags);
91 	regmap_read(master->regmap, master->layout->offset, &mckr);
92 	spin_unlock_irqrestore(master->lock, flags);
93 
94 	mckr &= layout->mask;
95 
96 	div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
97 
98 	rate /= characteristics->divisors[div];
99 
100 	if (rate < characteristics->output.min)
101 		pr_warn("master clk div is underclocked");
102 	else if (rate > characteristics->output.max)
103 		pr_warn("master clk div is overclocked");
104 
105 	return rate;
106 }
107 
108 static int clk_master_div_save_context(struct clk_hw *hw)
109 {
110 	struct clk_master *master = to_clk_master(hw);
111 	struct clk_hw *parent_hw = clk_hw_get_parent(hw);
112 	unsigned long flags;
113 	unsigned int mckr, div;
114 
115 	spin_lock_irqsave(master->lock, flags);
116 	regmap_read(master->regmap, master->layout->offset, &mckr);
117 	spin_unlock_irqrestore(master->lock, flags);
118 
119 	mckr &= master->layout->mask;
120 	div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
121 	div = master->characteristics->divisors[div];
122 
123 	master->pms.parent_rate = clk_hw_get_rate(parent_hw);
124 	master->pms.rate = DIV_ROUND_CLOSEST(master->pms.parent_rate, div);
125 
126 	return 0;
127 }
128 
129 static void clk_master_div_restore_context(struct clk_hw *hw)
130 {
131 	struct clk_master *master = to_clk_master(hw);
132 	unsigned long flags;
133 	unsigned int mckr;
134 	u8 div;
135 
136 	spin_lock_irqsave(master->lock, flags);
137 	regmap_read(master->regmap, master->layout->offset, &mckr);
138 	spin_unlock_irqrestore(master->lock, flags);
139 
140 	mckr &= master->layout->mask;
141 	div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
142 	div = master->characteristics->divisors[div];
143 
144 	if (div != DIV_ROUND_CLOSEST(master->pms.parent_rate, master->pms.rate))
145 		pr_warn("MCKR DIV not configured properly by firmware!\n");
146 }
147 
148 static const struct clk_ops master_div_ops = {
149 	.prepare = clk_master_prepare,
150 	.is_prepared = clk_master_is_prepared,
151 	.recalc_rate = clk_master_div_recalc_rate,
152 	.save_context = clk_master_div_save_context,
153 	.restore_context = clk_master_div_restore_context,
154 };
155 
156 static int clk_master_div_set_rate(struct clk_hw *hw, unsigned long rate,
157 				   unsigned long parent_rate)
158 {
159 	struct clk_master *master = to_clk_master(hw);
160 	const struct clk_master_characteristics *characteristics =
161 						master->characteristics;
162 	unsigned long flags;
163 	unsigned int mckr, tmp;
164 	int div, i;
165 	int ret;
166 
167 	div = DIV_ROUND_CLOSEST(parent_rate, rate);
168 	if (div > ARRAY_SIZE(characteristics->divisors))
169 		return -EINVAL;
170 
171 	for (i = 0; i < ARRAY_SIZE(characteristics->divisors); i++) {
172 		if (!characteristics->divisors[i])
173 			break;
174 
175 		if (div == characteristics->divisors[i]) {
176 			div = i;
177 			break;
178 		}
179 	}
180 
181 	if (i == ARRAY_SIZE(characteristics->divisors))
182 		return -EINVAL;
183 
184 	spin_lock_irqsave(master->lock, flags);
185 	ret = regmap_read(master->regmap, master->layout->offset, &mckr);
186 	if (ret)
187 		goto unlock;
188 
189 	tmp = mckr & master->layout->mask;
190 	tmp = (tmp >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
191 	if (tmp == div)
192 		goto unlock;
193 
194 	mckr &= ~(MASTER_DIV_MASK << MASTER_DIV_SHIFT);
195 	mckr |= (div << MASTER_DIV_SHIFT);
196 	ret = regmap_write(master->regmap, master->layout->offset, mckr);
197 	if (ret)
198 		goto unlock;
199 
200 	while (!clk_master_ready(master))
201 		cpu_relax();
202 unlock:
203 	spin_unlock_irqrestore(master->lock, flags);
204 
205 	return 0;
206 }
207 
208 static int clk_master_div_determine_rate(struct clk_hw *hw,
209 					 struct clk_rate_request *req)
210 {
211 	struct clk_master *master = to_clk_master(hw);
212 	const struct clk_master_characteristics *characteristics =
213 						master->characteristics;
214 	struct clk_hw *parent;
215 	unsigned long parent_rate, tmp_rate, best_rate = 0;
216 	int i, best_diff = INT_MIN, tmp_diff;
217 
218 	parent = clk_hw_get_parent(hw);
219 	if (!parent)
220 		return -EINVAL;
221 
222 	parent_rate = clk_hw_get_rate(parent);
223 	if (!parent_rate)
224 		return -EINVAL;
225 
226 	for (i = 0; i < ARRAY_SIZE(characteristics->divisors); i++) {
227 		if (!characteristics->divisors[i])
228 			break;
229 
230 		tmp_rate = DIV_ROUND_CLOSEST_ULL(parent_rate,
231 						 characteristics->divisors[i]);
232 		tmp_diff = abs(tmp_rate - req->rate);
233 
234 		if (!best_rate || best_diff > tmp_diff) {
235 			best_diff = tmp_diff;
236 			best_rate = tmp_rate;
237 		}
238 
239 		if (!best_diff)
240 			break;
241 	}
242 
243 	req->best_parent_rate = best_rate;
244 	req->best_parent_hw = parent;
245 	req->rate = best_rate;
246 
247 	return 0;
248 }
249 
250 static void clk_master_div_restore_context_chg(struct clk_hw *hw)
251 {
252 	struct clk_master *master = to_clk_master(hw);
253 	int ret;
254 
255 	ret = clk_master_div_set_rate(hw, master->pms.rate,
256 				      master->pms.parent_rate);
257 	if (ret)
258 		pr_warn("Failed to restore MCK DIV clock\n");
259 }
260 
261 static const struct clk_ops master_div_ops_chg = {
262 	.prepare = clk_master_prepare,
263 	.is_prepared = clk_master_is_prepared,
264 	.recalc_rate = clk_master_div_recalc_rate,
265 	.determine_rate = clk_master_div_determine_rate,
266 	.set_rate = clk_master_div_set_rate,
267 	.save_context = clk_master_div_save_context,
268 	.restore_context = clk_master_div_restore_context_chg,
269 };
270 
271 static void clk_sama7g5_master_best_diff(struct clk_rate_request *req,
272 					 struct clk_hw *parent,
273 					 unsigned long parent_rate,
274 					 long *best_rate,
275 					 long *best_diff,
276 					 u32 div)
277 {
278 	unsigned long tmp_rate, tmp_diff;
279 
280 	if (div == MASTER_PRES_MAX)
281 		tmp_rate = parent_rate / 3;
282 	else
283 		tmp_rate = parent_rate >> div;
284 
285 	tmp_diff = abs(req->rate - tmp_rate);
286 
287 	if (*best_diff < 0 || *best_diff >= tmp_diff) {
288 		*best_rate = tmp_rate;
289 		*best_diff = tmp_diff;
290 		req->best_parent_rate = parent_rate;
291 		req->best_parent_hw = parent;
292 	}
293 }
294 
295 static int clk_master_pres_determine_rate(struct clk_hw *hw,
296 					  struct clk_rate_request *req)
297 {
298 	struct clk_master *master = to_clk_master(hw);
299 	struct clk_rate_request req_parent = *req;
300 	const struct clk_master_characteristics *characteristics =
301 							master->characteristics;
302 	struct clk_hw *parent;
303 	long best_rate = LONG_MIN, best_diff = LONG_MIN;
304 	u32 pres;
305 	int i;
306 
307 	if (master->chg_pid < 0)
308 		return -EOPNOTSUPP;
309 
310 	parent = clk_hw_get_parent_by_index(hw, master->chg_pid);
311 	if (!parent)
312 		return -EOPNOTSUPP;
313 
314 	for (i = 0; i <= MASTER_PRES_MAX; i++) {
315 		if (characteristics->have_div3_pres && i == MASTER_PRES_MAX)
316 			pres = 3;
317 		else
318 			pres = 1 << i;
319 
320 		req_parent.rate = req->rate * pres;
321 		if (__clk_determine_rate(parent, &req_parent))
322 			continue;
323 
324 		clk_sama7g5_master_best_diff(req, parent, req_parent.rate,
325 					     &best_diff, &best_rate, pres);
326 		if (!best_diff)
327 			break;
328 	}
329 
330 	return 0;
331 }
332 
333 static int clk_master_pres_set_rate(struct clk_hw *hw, unsigned long rate,
334 				    unsigned long parent_rate)
335 {
336 	struct clk_master *master = to_clk_master(hw);
337 	unsigned long flags;
338 	unsigned int pres, mckr, tmp;
339 	int ret;
340 
341 	pres = DIV_ROUND_CLOSEST(parent_rate, rate);
342 	if (pres > MASTER_PRES_MAX)
343 		return -EINVAL;
344 
345 	else if (pres == 3)
346 		pres = MASTER_PRES_MAX;
347 	else
348 		pres = ffs(pres) - 1;
349 
350 	spin_lock_irqsave(master->lock, flags);
351 	ret = regmap_read(master->regmap, master->layout->offset, &mckr);
352 	if (ret)
353 		goto unlock;
354 
355 	mckr &= master->layout->mask;
356 	tmp = (mckr >> master->layout->pres_shift) & MASTER_PRES_MASK;
357 	if (pres == tmp)
358 		goto unlock;
359 
360 	mckr &= ~(MASTER_PRES_MASK << master->layout->pres_shift);
361 	mckr |= (pres << master->layout->pres_shift);
362 	ret = regmap_write(master->regmap, master->layout->offset, mckr);
363 	if (ret)
364 		goto unlock;
365 
366 	while (!clk_master_ready(master))
367 		cpu_relax();
368 unlock:
369 	spin_unlock_irqrestore(master->lock, flags);
370 
371 	return ret;
372 }
373 
374 static unsigned long clk_master_pres_recalc_rate(struct clk_hw *hw,
375 						 unsigned long parent_rate)
376 {
377 	struct clk_master *master = to_clk_master(hw);
378 	const struct clk_master_characteristics *characteristics =
379 						master->characteristics;
380 	unsigned long flags;
381 	unsigned int val, pres;
382 
383 	spin_lock_irqsave(master->lock, flags);
384 	regmap_read(master->regmap, master->layout->offset, &val);
385 	spin_unlock_irqrestore(master->lock, flags);
386 
387 	pres = (val >> master->layout->pres_shift) & MASTER_PRES_MASK;
388 	if (pres == 3 && characteristics->have_div3_pres)
389 		pres = 3;
390 	else
391 		pres = (1 << pres);
392 
393 	return DIV_ROUND_CLOSEST_ULL(parent_rate, pres);
394 }
395 
396 static u8 clk_master_pres_get_parent(struct clk_hw *hw)
397 {
398 	struct clk_master *master = to_clk_master(hw);
399 	unsigned long flags;
400 	unsigned int mckr;
401 
402 	spin_lock_irqsave(master->lock, flags);
403 	regmap_read(master->regmap, master->layout->offset, &mckr);
404 	spin_unlock_irqrestore(master->lock, flags);
405 
406 	return mckr & AT91_PMC_CSS;
407 }
408 
409 static int clk_master_pres_save_context(struct clk_hw *hw)
410 {
411 	struct clk_master *master = to_clk_master(hw);
412 	struct clk_hw *parent_hw = clk_hw_get_parent(hw);
413 	unsigned long flags;
414 	unsigned int val, pres;
415 
416 	spin_lock_irqsave(master->lock, flags);
417 	regmap_read(master->regmap, master->layout->offset, &val);
418 	spin_unlock_irqrestore(master->lock, flags);
419 
420 	val &= master->layout->mask;
421 	pres = (val >> master->layout->pres_shift) & MASTER_PRES_MASK;
422 	if (pres == MASTER_PRES_MAX && master->characteristics->have_div3_pres)
423 		pres = 3;
424 	else
425 		pres = (1 << pres);
426 
427 	master->pms.parent = val & AT91_PMC_CSS;
428 	master->pms.parent_rate = clk_hw_get_rate(parent_hw);
429 	master->pms.rate = DIV_ROUND_CLOSEST_ULL(master->pms.parent_rate, pres);
430 
431 	return 0;
432 }
433 
434 static void clk_master_pres_restore_context(struct clk_hw *hw)
435 {
436 	struct clk_master *master = to_clk_master(hw);
437 	unsigned long flags;
438 	unsigned int val, pres;
439 
440 	spin_lock_irqsave(master->lock, flags);
441 	regmap_read(master->regmap, master->layout->offset, &val);
442 	spin_unlock_irqrestore(master->lock, flags);
443 
444 	val &= master->layout->mask;
445 	pres = (val >> master->layout->pres_shift) & MASTER_PRES_MASK;
446 	if (pres == MASTER_PRES_MAX && master->characteristics->have_div3_pres)
447 		pres = 3;
448 	else
449 		pres = (1 << pres);
450 
451 	if (master->pms.rate !=
452 	    DIV_ROUND_CLOSEST_ULL(master->pms.parent_rate, pres) ||
453 	    (master->pms.parent != (val & AT91_PMC_CSS)))
454 		pr_warn("MCKR PRES was not configured properly by firmware!\n");
455 }
456 
457 static void clk_master_pres_restore_context_chg(struct clk_hw *hw)
458 {
459 	struct clk_master *master = to_clk_master(hw);
460 
461 	clk_master_pres_set_rate(hw, master->pms.rate, master->pms.parent_rate);
462 }
463 
464 static const struct clk_ops master_pres_ops = {
465 	.prepare = clk_master_prepare,
466 	.is_prepared = clk_master_is_prepared,
467 	.recalc_rate = clk_master_pres_recalc_rate,
468 	.get_parent = clk_master_pres_get_parent,
469 	.save_context = clk_master_pres_save_context,
470 	.restore_context = clk_master_pres_restore_context,
471 };
472 
473 static const struct clk_ops master_pres_ops_chg = {
474 	.prepare = clk_master_prepare,
475 	.is_prepared = clk_master_is_prepared,
476 	.determine_rate = clk_master_pres_determine_rate,
477 	.recalc_rate = clk_master_pres_recalc_rate,
478 	.get_parent = clk_master_pres_get_parent,
479 	.set_rate = clk_master_pres_set_rate,
480 	.save_context = clk_master_pres_save_context,
481 	.restore_context = clk_master_pres_restore_context_chg,
482 };
483 
484 static struct clk_hw * __init
485 at91_clk_register_master_internal(struct regmap *regmap,
486 		const char *name, int num_parents,
487 		const char **parent_names,
488 		const struct clk_master_layout *layout,
489 		const struct clk_master_characteristics *characteristics,
490 		const struct clk_ops *ops, spinlock_t *lock, u32 flags,
491 		int chg_pid)
492 {
493 	struct clk_master *master;
494 	struct clk_init_data init;
495 	struct clk_hw *hw;
496 	int ret;
497 
498 	if (!name || !num_parents || !parent_names || !lock)
499 		return ERR_PTR(-EINVAL);
500 
501 	master = kzalloc(sizeof(*master), GFP_KERNEL);
502 	if (!master)
503 		return ERR_PTR(-ENOMEM);
504 
505 	init.name = name;
506 	init.ops = ops;
507 	init.parent_names = parent_names;
508 	init.num_parents = num_parents;
509 	init.flags = flags;
510 
511 	master->hw.init = &init;
512 	master->layout = layout;
513 	master->characteristics = characteristics;
514 	master->regmap = regmap;
515 	master->chg_pid = chg_pid;
516 	master->lock = lock;
517 
518 	hw = &master->hw;
519 	ret = clk_hw_register(NULL, &master->hw);
520 	if (ret) {
521 		kfree(master);
522 		hw = ERR_PTR(ret);
523 	}
524 
525 	return hw;
526 }
527 
528 struct clk_hw * __init
529 at91_clk_register_master_pres(struct regmap *regmap,
530 		const char *name, int num_parents,
531 		const char **parent_names,
532 		const struct clk_master_layout *layout,
533 		const struct clk_master_characteristics *characteristics,
534 		spinlock_t *lock, u32 flags, int chg_pid)
535 {
536 	const struct clk_ops *ops;
537 
538 	if (flags & CLK_SET_RATE_GATE)
539 		ops = &master_pres_ops;
540 	else
541 		ops = &master_pres_ops_chg;
542 
543 	return at91_clk_register_master_internal(regmap, name, num_parents,
544 						 parent_names, layout,
545 						 characteristics, ops,
546 						 lock, flags, chg_pid);
547 }
548 
549 struct clk_hw * __init
550 at91_clk_register_master_div(struct regmap *regmap,
551 		const char *name, const char *parent_name,
552 		const struct clk_master_layout *layout,
553 		const struct clk_master_characteristics *characteristics,
554 		spinlock_t *lock, u32 flags)
555 {
556 	const struct clk_ops *ops;
557 
558 	if (flags & CLK_SET_RATE_GATE)
559 		ops = &master_div_ops;
560 	else
561 		ops = &master_div_ops_chg;
562 
563 	return at91_clk_register_master_internal(regmap, name, 1,
564 						 &parent_name, layout,
565 						 characteristics, ops,
566 						 lock, flags, -EINVAL);
567 }
568 
569 static unsigned long
570 clk_sama7g5_master_recalc_rate(struct clk_hw *hw,
571 			       unsigned long parent_rate)
572 {
573 	struct clk_master *master = to_clk_master(hw);
574 
575 	return DIV_ROUND_CLOSEST_ULL(parent_rate, (1 << master->div));
576 }
577 
578 static int clk_sama7g5_master_determine_rate(struct clk_hw *hw,
579 					     struct clk_rate_request *req)
580 {
581 	struct clk_master *master = to_clk_master(hw);
582 	struct clk_rate_request req_parent = *req;
583 	struct clk_hw *parent;
584 	long best_rate = LONG_MIN, best_diff = LONG_MIN;
585 	unsigned long parent_rate;
586 	unsigned int div, i;
587 
588 	/* First: check the dividers of MCR. */
589 	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
590 		parent = clk_hw_get_parent_by_index(hw, i);
591 		if (!parent)
592 			continue;
593 
594 		parent_rate = clk_hw_get_rate(parent);
595 		if (!parent_rate)
596 			continue;
597 
598 		for (div = 0; div < MASTER_PRES_MAX + 1; div++) {
599 			clk_sama7g5_master_best_diff(req, parent, parent_rate,
600 						     &best_rate, &best_diff,
601 						     div);
602 			if (!best_diff)
603 				break;
604 		}
605 
606 		if (!best_diff)
607 			break;
608 	}
609 
610 	/* Second: try to request rate form changeable parent. */
611 	if (master->chg_pid < 0)
612 		goto end;
613 
614 	parent = clk_hw_get_parent_by_index(hw, master->chg_pid);
615 	if (!parent)
616 		goto end;
617 
618 	for (div = 0; div < MASTER_PRES_MAX + 1; div++) {
619 		if (div == MASTER_PRES_MAX)
620 			req_parent.rate = req->rate * 3;
621 		else
622 			req_parent.rate = req->rate << div;
623 
624 		if (__clk_determine_rate(parent, &req_parent))
625 			continue;
626 
627 		clk_sama7g5_master_best_diff(req, parent, req_parent.rate,
628 					     &best_rate, &best_diff, div);
629 
630 		if (!best_diff)
631 			break;
632 	}
633 
634 end:
635 	pr_debug("MCK: %s, best_rate = %ld, parent clk: %s @ %ld\n",
636 		 __func__, best_rate,
637 		 __clk_get_name((req->best_parent_hw)->clk),
638 		req->best_parent_rate);
639 
640 	if (best_rate < 0)
641 		return -EINVAL;
642 
643 	req->rate = best_rate;
644 
645 	return 0;
646 }
647 
648 static u8 clk_sama7g5_master_get_parent(struct clk_hw *hw)
649 {
650 	struct clk_master *master = to_clk_master(hw);
651 	unsigned long flags;
652 	u8 index;
653 
654 	spin_lock_irqsave(master->lock, flags);
655 	index = clk_mux_val_to_index(&master->hw, master->mux_table, 0,
656 				     master->parent);
657 	spin_unlock_irqrestore(master->lock, flags);
658 
659 	return index;
660 }
661 
662 static int clk_sama7g5_master_set_parent(struct clk_hw *hw, u8 index)
663 {
664 	struct clk_master *master = to_clk_master(hw);
665 	unsigned long flags;
666 
667 	if (index >= clk_hw_get_num_parents(hw))
668 		return -EINVAL;
669 
670 	spin_lock_irqsave(master->lock, flags);
671 	master->parent = clk_mux_index_to_val(master->mux_table, 0, index);
672 	spin_unlock_irqrestore(master->lock, flags);
673 
674 	return 0;
675 }
676 
677 static void clk_sama7g5_master_set(struct clk_master *master,
678 				   unsigned int status)
679 {
680 	unsigned long flags;
681 	unsigned int val, cparent;
682 	unsigned int enable = status ? AT91_PMC_MCR_V2_EN : 0;
683 
684 	spin_lock_irqsave(master->lock, flags);
685 
686 	regmap_write(master->regmap, AT91_PMC_MCR_V2,
687 		     AT91_PMC_MCR_V2_ID(master->id));
688 	regmap_read(master->regmap, AT91_PMC_MCR_V2, &val);
689 	regmap_update_bits(master->regmap, AT91_PMC_MCR_V2,
690 			   enable | AT91_PMC_MCR_V2_CSS | AT91_PMC_MCR_V2_DIV |
691 			   AT91_PMC_MCR_V2_CMD | AT91_PMC_MCR_V2_ID_MSK,
692 			   enable | (master->parent << PMC_MCR_CSS_SHIFT) |
693 			   (master->div << MASTER_DIV_SHIFT) |
694 			   AT91_PMC_MCR_V2_CMD |
695 			   AT91_PMC_MCR_V2_ID(master->id));
696 
697 	cparent = (val & AT91_PMC_MCR_V2_CSS) >> PMC_MCR_CSS_SHIFT;
698 
699 	/* Wait here only if parent is being changed. */
700 	while ((cparent != master->parent) && !clk_master_ready(master))
701 		cpu_relax();
702 
703 	spin_unlock_irqrestore(master->lock, flags);
704 }
705 
706 static int clk_sama7g5_master_enable(struct clk_hw *hw)
707 {
708 	struct clk_master *master = to_clk_master(hw);
709 
710 	clk_sama7g5_master_set(master, 1);
711 
712 	return 0;
713 }
714 
715 static void clk_sama7g5_master_disable(struct clk_hw *hw)
716 {
717 	struct clk_master *master = to_clk_master(hw);
718 	unsigned long flags;
719 
720 	spin_lock_irqsave(master->lock, flags);
721 
722 	regmap_write(master->regmap, AT91_PMC_MCR_V2, master->id);
723 	regmap_update_bits(master->regmap, AT91_PMC_MCR_V2,
724 			   AT91_PMC_MCR_V2_EN | AT91_PMC_MCR_V2_CMD |
725 			   AT91_PMC_MCR_V2_ID_MSK,
726 			   AT91_PMC_MCR_V2_CMD |
727 			   AT91_PMC_MCR_V2_ID(master->id));
728 
729 	spin_unlock_irqrestore(master->lock, flags);
730 }
731 
732 static int clk_sama7g5_master_is_enabled(struct clk_hw *hw)
733 {
734 	struct clk_master *master = to_clk_master(hw);
735 	unsigned long flags;
736 	unsigned int val;
737 
738 	spin_lock_irqsave(master->lock, flags);
739 
740 	regmap_write(master->regmap, AT91_PMC_MCR_V2, master->id);
741 	regmap_read(master->regmap, AT91_PMC_MCR_V2, &val);
742 
743 	spin_unlock_irqrestore(master->lock, flags);
744 
745 	return !!(val & AT91_PMC_MCR_V2_EN);
746 }
747 
748 static int clk_sama7g5_master_set_rate(struct clk_hw *hw, unsigned long rate,
749 				       unsigned long parent_rate)
750 {
751 	struct clk_master *master = to_clk_master(hw);
752 	unsigned long div, flags;
753 
754 	div = DIV_ROUND_CLOSEST(parent_rate, rate);
755 	if ((div > (1 << (MASTER_PRES_MAX - 1))) || (div & (div - 1)))
756 		return -EINVAL;
757 
758 	if (div == 3)
759 		div = MASTER_PRES_MAX;
760 	else
761 		div = ffs(div) - 1;
762 
763 	spin_lock_irqsave(master->lock, flags);
764 	master->div = div;
765 	spin_unlock_irqrestore(master->lock, flags);
766 
767 	return 0;
768 }
769 
770 static int clk_sama7g5_master_save_context(struct clk_hw *hw)
771 {
772 	struct clk_master *master = to_clk_master(hw);
773 
774 	master->pms.status = clk_sama7g5_master_is_enabled(hw);
775 
776 	return 0;
777 }
778 
779 static void clk_sama7g5_master_restore_context(struct clk_hw *hw)
780 {
781 	struct clk_master *master = to_clk_master(hw);
782 
783 	if (master->pms.status)
784 		clk_sama7g5_master_set(master, master->pms.status);
785 }
786 
787 static const struct clk_ops sama7g5_master_ops = {
788 	.enable = clk_sama7g5_master_enable,
789 	.disable = clk_sama7g5_master_disable,
790 	.is_enabled = clk_sama7g5_master_is_enabled,
791 	.recalc_rate = clk_sama7g5_master_recalc_rate,
792 	.determine_rate = clk_sama7g5_master_determine_rate,
793 	.set_rate = clk_sama7g5_master_set_rate,
794 	.get_parent = clk_sama7g5_master_get_parent,
795 	.set_parent = clk_sama7g5_master_set_parent,
796 	.save_context = clk_sama7g5_master_save_context,
797 	.restore_context = clk_sama7g5_master_restore_context,
798 };
799 
800 struct clk_hw * __init
801 at91_clk_sama7g5_register_master(struct regmap *regmap,
802 				 const char *name, int num_parents,
803 				 const char **parent_names,
804 				 u32 *mux_table,
805 				 spinlock_t *lock, u8 id,
806 				 bool critical, int chg_pid)
807 {
808 	struct clk_master *master;
809 	struct clk_hw *hw;
810 	struct clk_init_data init;
811 	unsigned long flags;
812 	unsigned int val;
813 	int ret;
814 
815 	if (!name || !num_parents || !parent_names || !mux_table ||
816 	    !lock || id > MASTER_MAX_ID)
817 		return ERR_PTR(-EINVAL);
818 
819 	master = kzalloc(sizeof(*master), GFP_KERNEL);
820 	if (!master)
821 		return ERR_PTR(-ENOMEM);
822 
823 	init.name = name;
824 	init.ops = &sama7g5_master_ops;
825 	init.parent_names = parent_names;
826 	init.num_parents = num_parents;
827 	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
828 	if (chg_pid >= 0)
829 		init.flags |= CLK_SET_RATE_PARENT;
830 	if (critical)
831 		init.flags |= CLK_IS_CRITICAL;
832 
833 	master->hw.init = &init;
834 	master->regmap = regmap;
835 	master->id = id;
836 	master->chg_pid = chg_pid;
837 	master->lock = lock;
838 	master->mux_table = mux_table;
839 
840 	spin_lock_irqsave(master->lock, flags);
841 	regmap_write(master->regmap, AT91_PMC_MCR_V2, master->id);
842 	regmap_read(master->regmap, AT91_PMC_MCR_V2, &val);
843 	master->parent = (val & AT91_PMC_MCR_V2_CSS) >> PMC_MCR_CSS_SHIFT;
844 	master->div = (val & AT91_PMC_MCR_V2_DIV) >> MASTER_DIV_SHIFT;
845 	spin_unlock_irqrestore(master->lock, flags);
846 
847 	hw = &master->hw;
848 	ret = clk_hw_register(NULL, &master->hw);
849 	if (ret) {
850 		kfree(master);
851 		hw = ERR_PTR(ret);
852 	}
853 
854 	return hw;
855 }
856 
857 const struct clk_master_layout at91rm9200_master_layout = {
858 	.mask = 0x31F,
859 	.pres_shift = 2,
860 	.offset = AT91_PMC_MCKR,
861 };
862 
863 const struct clk_master_layout at91sam9x5_master_layout = {
864 	.mask = 0x373,
865 	.pres_shift = 4,
866 	.offset = AT91_PMC_MCKR,
867 };
868