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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 0x30
21#define PMC_MCR_ID_MSK GENMASK(3, 0)
22#define PMC_MCR_CMD BIT(7)
23#define PMC_MCR_DIV GENMASK(10, 8)
24#define PMC_MCR_CSS GENMASK(20, 16)
25#define PMC_MCR_CSS_SHIFT (16)
26#define PMC_MCR_EN BIT(28)
27
28#define PMC_MCR_ID(x) ((x) & PMC_MCR_ID_MSK)
29
30#define MASTER_MAX_ID 4
31
32#define to_clk_master(hw) container_of(hw, struct clk_master, hw)
33
34struct clk_master {
35 struct clk_hw hw;
36 struct regmap *regmap;
37 spinlock_t *lock;
38 const struct clk_master_layout *layout;
39 const struct clk_master_characteristics *characteristics;
40 u32 *mux_table;
41 u32 mckr;
42 int chg_pid;
43 u8 id;
44 u8 parent;
45 u8 div;
46};
47
48static inline bool clk_master_ready(struct clk_master *master)
49{
50 unsigned int bit = master->id ? AT91_PMC_MCKXRDY : AT91_PMC_MCKRDY;
51 unsigned int status;
52
53 regmap_read(master->regmap, AT91_PMC_SR, &status);
54
55 return !!(status & bit);
56}
57
58static int clk_master_prepare(struct clk_hw *hw)
59{
60 struct clk_master *master = to_clk_master(hw);
61 unsigned long flags;
62
63 spin_lock_irqsave(master->lock, flags);
64
65 while (!clk_master_ready(master))
66 cpu_relax();
67
68 spin_unlock_irqrestore(master->lock, flags);
69
70 return 0;
71}
72
73static int clk_master_is_prepared(struct clk_hw *hw)
74{
75 struct clk_master *master = to_clk_master(hw);
76 unsigned long flags;
77 bool status;
78
79 spin_lock_irqsave(master->lock, flags);
80 status = clk_master_ready(master);
81 spin_unlock_irqrestore(master->lock, flags);
82
83 return status;
84}
85
86static unsigned long clk_master_div_recalc_rate(struct clk_hw *hw,
87 unsigned long parent_rate)
88{
89 u8 div;
90 unsigned long flags, rate = parent_rate;
91 struct clk_master *master = to_clk_master(hw);
92 const struct clk_master_layout *layout = master->layout;
93 const struct clk_master_characteristics *characteristics =
94 master->characteristics;
95 unsigned int mckr;
96
97 spin_lock_irqsave(master->lock, flags);
98 regmap_read(master->regmap, master->layout->offset, &mckr);
99 spin_unlock_irqrestore(master->lock, flags);
100
101 mckr &= layout->mask;
102
103 div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK;
104
105 rate /= characteristics->divisors[div];
106
107 if (rate < characteristics->output.min)
108 pr_warn("master clk div is underclocked");
109 else if (rate > characteristics->output.max)
110 pr_warn("master clk div is overclocked");
111
112 return rate;
113}
114
115static const struct clk_ops master_div_ops = {
116 .prepare = clk_master_prepare,
117 .is_prepared = clk_master_is_prepared,
118 .recalc_rate = clk_master_div_recalc_rate,
119};
120
121static int clk_master_div_set_rate(struct clk_hw *hw, unsigned long rate,
122 unsigned long parent_rate)
123{
124 struct clk_master *master = to_clk_master(hw);
125 const struct clk_master_characteristics *characteristics =
126 master->characteristics;
127 unsigned long flags;
128 int div, i;
129
130 div = DIV_ROUND_CLOSEST(parent_rate, rate);
131 if (div > ARRAY_SIZE(characteristics->divisors))
132 return -EINVAL;
133
134 for (i = 0; i < ARRAY_SIZE(characteristics->divisors); i++) {
135 if (!characteristics->divisors[i])
136 break;
137
138 if (div == characteristics->divisors[i]) {
139 div = i;
140 break;
141 }
142 }
143
144 if (i == ARRAY_SIZE(characteristics->divisors))
145 return -EINVAL;
146
147 spin_lock_irqsave(master->lock, flags);
148 regmap_update_bits(master->regmap, master->layout->offset,
149 (MASTER_DIV_MASK << MASTER_DIV_SHIFT),
150 (div << MASTER_DIV_SHIFT));
151 while (!clk_master_ready(master))
152 cpu_relax();
153 spin_unlock_irqrestore(master->lock, flags);
154
155 return 0;
156}
157
158static int clk_master_div_determine_rate(struct clk_hw *hw,
159 struct clk_rate_request *req)
160{
161 struct clk_master *master = to_clk_master(hw);
162 const struct clk_master_characteristics *characteristics =
163 master->characteristics;
164 struct clk_hw *parent;
165 unsigned long parent_rate, tmp_rate, best_rate = 0;
166 int i, best_diff = INT_MIN, tmp_diff;
167
168 parent = clk_hw_get_parent(hw);
169 if (!parent)
170 return -EINVAL;
171
172 parent_rate = clk_hw_get_rate(parent);
173 if (!parent_rate)
174 return -EINVAL;
175
176 for (i = 0; i < ARRAY_SIZE(characteristics->divisors); i++) {
177 if (!characteristics->divisors[i])
178 break;
179
180 tmp_rate = DIV_ROUND_CLOSEST_ULL(parent_rate,
181 characteristics->divisors[i]);
182 tmp_diff = abs(tmp_rate - req->rate);
183
184 if (!best_rate || best_diff > tmp_diff) {
185 best_diff = tmp_diff;
186 best_rate = tmp_rate;
187 }
188
189 if (!best_diff)
190 break;
191 }
192
193 req->best_parent_rate = best_rate;
194 req->best_parent_hw = parent;
195 req->rate = best_rate;
196
197 return 0;
198}
199
200static const struct clk_ops master_div_ops_chg = {
201 .prepare = clk_master_prepare,
202 .is_prepared = clk_master_is_prepared,
203 .recalc_rate = clk_master_div_recalc_rate,
204 .determine_rate = clk_master_div_determine_rate,
205 .set_rate = clk_master_div_set_rate,
206};
207
208static void clk_sama7g5_master_best_diff(struct clk_rate_request *req,
209 struct clk_hw *parent,
210 unsigned long parent_rate,
211 long *best_rate,
212 long *best_diff,
213 u32 div)
214{
215 unsigned long tmp_rate, tmp_diff;
216
217 if (div == MASTER_PRES_MAX)
218 tmp_rate = parent_rate / 3;
219 else
220 tmp_rate = parent_rate >> div;
221
222 tmp_diff = abs(req->rate - tmp_rate);
223
224 if (*best_diff < 0 || *best_diff >= tmp_diff) {
225 *best_rate = tmp_rate;
226 *best_diff = tmp_diff;
227 req->best_parent_rate = parent_rate;
228 req->best_parent_hw = parent;
229 }
230}
231
232static int clk_master_pres_determine_rate(struct clk_hw *hw,
233 struct clk_rate_request *req)
234{
235 struct clk_master *master = to_clk_master(hw);
236 struct clk_rate_request req_parent = *req;
237 const struct clk_master_characteristics *characteristics =
238 master->characteristics;
239 struct clk_hw *parent;
240 long best_rate = LONG_MIN, best_diff = LONG_MIN;
241 u32 pres;
242 int i;
243
244 if (master->chg_pid < 0)
245 return -EOPNOTSUPP;
246
247 parent = clk_hw_get_parent_by_index(hw, master->chg_pid);
248 if (!parent)
249 return -EOPNOTSUPP;
250
251 for (i = 0; i <= MASTER_PRES_MAX; i++) {
252 if (characteristics->have_div3_pres && i == MASTER_PRES_MAX)
253 pres = 3;
254 else
255 pres = 1 << i;
256
257 req_parent.rate = req->rate * pres;
258 if (__clk_determine_rate(parent, &req_parent))
259 continue;
260
261 clk_sama7g5_master_best_diff(req, parent, req_parent.rate,
262 &best_diff, &best_rate, pres);
263 if (!best_diff)
264 break;
265 }
266
267 return 0;
268}
269
270static int clk_master_pres_set_rate(struct clk_hw *hw, unsigned long rate,
271 unsigned long parent_rate)
272{
273 struct clk_master *master = to_clk_master(hw);
274 unsigned long flags;
275 unsigned int pres;
276
277 pres = DIV_ROUND_CLOSEST(parent_rate, rate);
278 if (pres > MASTER_PRES_MAX)
279 return -EINVAL;
280
281 else if (pres == 3)
282 pres = MASTER_PRES_MAX;
283 else
284 pres = ffs(pres) - 1;
285
286 spin_lock_irqsave(master->lock, flags);
287 regmap_update_bits(master->regmap, master->layout->offset,
288 (MASTER_PRES_MASK << master->layout->pres_shift),
289 (pres << master->layout->pres_shift));
290
291 while (!clk_master_ready(master))
292 cpu_relax();
293 spin_unlock_irqrestore(master->lock, flags);
294
295 return 0;
296}
297
298static unsigned long clk_master_pres_recalc_rate(struct clk_hw *hw,
299 unsigned long parent_rate)
300{
301 struct clk_master *master = to_clk_master(hw);
302 const struct clk_master_characteristics *characteristics =
303 master->characteristics;
304 unsigned long flags;
305 unsigned int val, pres;
306
307 spin_lock_irqsave(master->lock, flags);
308 regmap_read(master->regmap, master->layout->offset, &val);
309 spin_unlock_irqrestore(master->lock, flags);
310
311 pres = (val >> master->layout->pres_shift) & MASTER_PRES_MASK;
312 if (pres == 3 && characteristics->have_div3_pres)
313 pres = 3;
314 else
315 pres = (1 << pres);
316
317 return DIV_ROUND_CLOSEST_ULL(parent_rate, pres);
318}
319
320static u8 clk_master_pres_get_parent(struct clk_hw *hw)
321{
322 struct clk_master *master = to_clk_master(hw);
323 unsigned long flags;
324 unsigned int mckr;
325
326 spin_lock_irqsave(master->lock, flags);
327 regmap_read(master->regmap, master->layout->offset, &mckr);
328 spin_unlock_irqrestore(master->lock, flags);
329
330 return mckr & AT91_PMC_CSS;
331}
332
333static const struct clk_ops master_pres_ops = {
334 .prepare = clk_master_prepare,
335 .is_prepared = clk_master_is_prepared,
336 .recalc_rate = clk_master_pres_recalc_rate,
337 .get_parent = clk_master_pres_get_parent,
338};
339
340static const struct clk_ops master_pres_ops_chg = {
341 .prepare = clk_master_prepare,
342 .is_prepared = clk_master_is_prepared,
343 .determine_rate = clk_master_pres_determine_rate,
344 .recalc_rate = clk_master_pres_recalc_rate,
345 .get_parent = clk_master_pres_get_parent,
346 .set_rate = clk_master_pres_set_rate,
347};
348
349static struct clk_hw * __init
350at91_clk_register_master_internal(struct regmap *regmap,
351 const char *name, int num_parents,
352 const char **parent_names,
353 const struct clk_master_layout *layout,
354 const struct clk_master_characteristics *characteristics,
355 const struct clk_ops *ops, spinlock_t *lock, u32 flags,
356 int chg_pid)
357{
358 struct clk_master *master;
359 struct clk_init_data init;
360 struct clk_hw *hw;
361 int ret;
362
363 if (!name || !num_parents || !parent_names || !lock)
364 return ERR_PTR(-EINVAL);
365
366 master = kzalloc(sizeof(*master), GFP_KERNEL);
367 if (!master)
368 return ERR_PTR(-ENOMEM);
369
370 init.name = name;
371 init.ops = ops;
372 init.parent_names = parent_names;
373 init.num_parents = num_parents;
374 init.flags = flags;
375
376 master->hw.init = &init;
377 master->layout = layout;
378 master->characteristics = characteristics;
379 master->regmap = regmap;
380 master->chg_pid = chg_pid;
381 master->lock = lock;
382
383 hw = &master->hw;
384 ret = clk_hw_register(NULL, &master->hw);
385 if (ret) {
386 kfree(master);
387 hw = ERR_PTR(ret);
388 }
389
390 return hw;
391}
392
393struct clk_hw * __init
394at91_clk_register_master_pres(struct regmap *regmap,
395 const char *name, int num_parents,
396 const char **parent_names,
397 const struct clk_master_layout *layout,
398 const struct clk_master_characteristics *characteristics,
399 spinlock_t *lock, u32 flags, int chg_pid)
400{
401 const struct clk_ops *ops;
402
403 if (flags & CLK_SET_RATE_GATE)
404 ops = &master_pres_ops;
405 else
406 ops = &master_pres_ops_chg;
407
408 return at91_clk_register_master_internal(regmap, name, num_parents,
409 parent_names, layout,
410 characteristics, ops,
411 lock, flags, chg_pid);
412}
413
414struct clk_hw * __init
415at91_clk_register_master_div(struct regmap *regmap,
416 const char *name, const char *parent_name,
417 const struct clk_master_layout *layout,
418 const struct clk_master_characteristics *characteristics,
419 spinlock_t *lock, u32 flags)
420{
421 const struct clk_ops *ops;
422
423 if (flags & CLK_SET_RATE_GATE)
424 ops = &master_div_ops;
425 else
426 ops = &master_div_ops_chg;
427
428 return at91_clk_register_master_internal(regmap, name, 1,
429 &parent_name, layout,
430 characteristics, ops,
431 lock, flags, -EINVAL);
432}
433
434static unsigned long
435clk_sama7g5_master_recalc_rate(struct clk_hw *hw,
436 unsigned long parent_rate)
437{
438 struct clk_master *master = to_clk_master(hw);
439
440 return DIV_ROUND_CLOSEST_ULL(parent_rate, (1 << master->div));
441}
442
443static int clk_sama7g5_master_determine_rate(struct clk_hw *hw,
444 struct clk_rate_request *req)
445{
446 struct clk_master *master = to_clk_master(hw);
447 struct clk_rate_request req_parent = *req;
448 struct clk_hw *parent;
449 long best_rate = LONG_MIN, best_diff = LONG_MIN;
450 unsigned long parent_rate;
451 unsigned int div, i;
452
453
454 for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
455 parent = clk_hw_get_parent_by_index(hw, i);
456 if (!parent)
457 continue;
458
459 parent_rate = clk_hw_get_rate(parent);
460 if (!parent_rate)
461 continue;
462
463 for (div = 0; div < MASTER_PRES_MAX + 1; div++) {
464 clk_sama7g5_master_best_diff(req, parent, parent_rate,
465 &best_rate, &best_diff,
466 div);
467 if (!best_diff)
468 break;
469 }
470
471 if (!best_diff)
472 break;
473 }
474
475
476 if (master->chg_pid < 0)
477 goto end;
478
479 parent = clk_hw_get_parent_by_index(hw, master->chg_pid);
480 if (!parent)
481 goto end;
482
483 for (div = 0; div < MASTER_PRES_MAX + 1; div++) {
484 if (div == MASTER_PRES_MAX)
485 req_parent.rate = req->rate * 3;
486 else
487 req_parent.rate = req->rate << div;
488
489 if (__clk_determine_rate(parent, &req_parent))
490 continue;
491
492 clk_sama7g5_master_best_diff(req, parent, req_parent.rate,
493 &best_rate, &best_diff, div);
494
495 if (!best_diff)
496 break;
497 }
498
499end:
500 pr_debug("MCK: %s, best_rate = %ld, parent clk: %s @ %ld\n",
501 __func__, best_rate,
502 __clk_get_name((req->best_parent_hw)->clk),
503 req->best_parent_rate);
504
505 if (best_rate < 0)
506 return -EINVAL;
507
508 req->rate = best_rate;
509
510 return 0;
511}
512
513static u8 clk_sama7g5_master_get_parent(struct clk_hw *hw)
514{
515 struct clk_master *master = to_clk_master(hw);
516 unsigned long flags;
517 u8 index;
518
519 spin_lock_irqsave(master->lock, flags);
520 index = clk_mux_val_to_index(&master->hw, master->mux_table, 0,
521 master->parent);
522 spin_unlock_irqrestore(master->lock, flags);
523
524 return index;
525}
526
527static int clk_sama7g5_master_set_parent(struct clk_hw *hw, u8 index)
528{
529 struct clk_master *master = to_clk_master(hw);
530 unsigned long flags;
531
532 if (index >= clk_hw_get_num_parents(hw))
533 return -EINVAL;
534
535 spin_lock_irqsave(master->lock, flags);
536 master->parent = clk_mux_index_to_val(master->mux_table, 0, index);
537 spin_unlock_irqrestore(master->lock, flags);
538
539 return 0;
540}
541
542static int clk_sama7g5_master_enable(struct clk_hw *hw)
543{
544 struct clk_master *master = to_clk_master(hw);
545 unsigned long flags;
546 unsigned int val, cparent;
547
548 spin_lock_irqsave(master->lock, flags);
549
550 regmap_write(master->regmap, PMC_MCR, PMC_MCR_ID(master->id));
551 regmap_read(master->regmap, PMC_MCR, &val);
552 regmap_update_bits(master->regmap, PMC_MCR,
553 PMC_MCR_EN | PMC_MCR_CSS | PMC_MCR_DIV |
554 PMC_MCR_CMD | PMC_MCR_ID_MSK,
555 PMC_MCR_EN | (master->parent << PMC_MCR_CSS_SHIFT) |
556 (master->div << MASTER_DIV_SHIFT) |
557 PMC_MCR_CMD | PMC_MCR_ID(master->id));
558
559 cparent = (val & PMC_MCR_CSS) >> PMC_MCR_CSS_SHIFT;
560
561
562 while ((cparent != master->parent) && !clk_master_ready(master))
563 cpu_relax();
564
565 spin_unlock_irqrestore(master->lock, flags);
566
567 return 0;
568}
569
570static void clk_sama7g5_master_disable(struct clk_hw *hw)
571{
572 struct clk_master *master = to_clk_master(hw);
573 unsigned long flags;
574
575 spin_lock_irqsave(master->lock, flags);
576
577 regmap_write(master->regmap, PMC_MCR, master->id);
578 regmap_update_bits(master->regmap, PMC_MCR,
579 PMC_MCR_EN | PMC_MCR_CMD | PMC_MCR_ID_MSK,
580 PMC_MCR_CMD | PMC_MCR_ID(master->id));
581
582 spin_unlock_irqrestore(master->lock, flags);
583}
584
585static int clk_sama7g5_master_is_enabled(struct clk_hw *hw)
586{
587 struct clk_master *master = to_clk_master(hw);
588 unsigned long flags;
589 unsigned int val;
590
591 spin_lock_irqsave(master->lock, flags);
592
593 regmap_write(master->regmap, PMC_MCR, master->id);
594 regmap_read(master->regmap, PMC_MCR, &val);
595
596 spin_unlock_irqrestore(master->lock, flags);
597
598 return !!(val & PMC_MCR_EN);
599}
600
601static int clk_sama7g5_master_set_rate(struct clk_hw *hw, unsigned long rate,
602 unsigned long parent_rate)
603{
604 struct clk_master *master = to_clk_master(hw);
605 unsigned long div, flags;
606
607 div = DIV_ROUND_CLOSEST(parent_rate, rate);
608 if ((div > (1 << (MASTER_PRES_MAX - 1))) || (div & (div - 1)))
609 return -EINVAL;
610
611 if (div == 3)
612 div = MASTER_PRES_MAX;
613 else
614 div = ffs(div) - 1;
615
616 spin_lock_irqsave(master->lock, flags);
617 master->div = div;
618 spin_unlock_irqrestore(master->lock, flags);
619
620 return 0;
621}
622
623static const struct clk_ops sama7g5_master_ops = {
624 .enable = clk_sama7g5_master_enable,
625 .disable = clk_sama7g5_master_disable,
626 .is_enabled = clk_sama7g5_master_is_enabled,
627 .recalc_rate = clk_sama7g5_master_recalc_rate,
628 .determine_rate = clk_sama7g5_master_determine_rate,
629 .set_rate = clk_sama7g5_master_set_rate,
630 .get_parent = clk_sama7g5_master_get_parent,
631 .set_parent = clk_sama7g5_master_set_parent,
632};
633
634struct clk_hw * __init
635at91_clk_sama7g5_register_master(struct regmap *regmap,
636 const char *name, int num_parents,
637 const char **parent_names,
638 u32 *mux_table,
639 spinlock_t *lock, u8 id,
640 bool critical, int chg_pid)
641{
642 struct clk_master *master;
643 struct clk_hw *hw;
644 struct clk_init_data init;
645 unsigned long flags;
646 unsigned int val;
647 int ret;
648
649 if (!name || !num_parents || !parent_names || !mux_table ||
650 !lock || id > MASTER_MAX_ID)
651 return ERR_PTR(-EINVAL);
652
653 master = kzalloc(sizeof(*master), GFP_KERNEL);
654 if (!master)
655 return ERR_PTR(-ENOMEM);
656
657 init.name = name;
658 init.ops = &sama7g5_master_ops;
659 init.parent_names = parent_names;
660 init.num_parents = num_parents;
661 init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
662 if (chg_pid >= 0)
663 init.flags |= CLK_SET_RATE_PARENT;
664 if (critical)
665 init.flags |= CLK_IS_CRITICAL;
666
667 master->hw.init = &init;
668 master->regmap = regmap;
669 master->id = id;
670 master->chg_pid = chg_pid;
671 master->lock = lock;
672 master->mux_table = mux_table;
673
674 spin_lock_irqsave(master->lock, flags);
675 regmap_write(master->regmap, PMC_MCR, master->id);
676 regmap_read(master->regmap, PMC_MCR, &val);
677 master->parent = (val & PMC_MCR_CSS) >> PMC_MCR_CSS_SHIFT;
678 master->div = (val & PMC_MCR_DIV) >> MASTER_DIV_SHIFT;
679 spin_unlock_irqrestore(master->lock, flags);
680
681 hw = &master->hw;
682 ret = clk_hw_register(NULL, &master->hw);
683 if (ret) {
684 kfree(master);
685 hw = ERR_PTR(ret);
686 }
687
688 return hw;
689}
690
691const struct clk_master_layout at91rm9200_master_layout = {
692 .mask = 0x31F,
693 .pres_shift = 2,
694 .offset = AT91_PMC_MCKR,
695};
696
697const struct clk_master_layout at91sam9x5_master_layout = {
698 .mask = 0x373,
699 .pres_shift = 4,
700 .offset = AT91_PMC_MCKR,
701};
702
