Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
4 * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
5 * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
6 *
7 * Adjustable divider clock implementation
8 */
9
10#include <linux/clk-provider.h>
11#include <linux/device.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/io.h>
15#include <linux/err.h>
16#include <linux/string.h>
17#include <linux/log2.h>
18
19/*
20 * DOC: basic adjustable divider clock that cannot gate
21 *
22 * Traits of this clock:
23 * prepare - clk_prepare only ensures that parents are prepared
24 * enable - clk_enable only ensures that parents are enabled
25 * rate - rate is adjustable. clk->rate = ceiling(parent->rate / divisor)
26 * parent - fixed parent. No clk_set_parent support
27 */
28
29static inline u32 clk_div_readl(struct clk_divider *divider)
30{
31 if (divider->flags & CLK_DIVIDER_BIG_ENDIAN)
32 return ioread32be(divider->reg);
33
34 return readl(divider->reg);
35}
36
37static inline void clk_div_writel(struct clk_divider *divider, u32 val)
38{
39 if (divider->flags & CLK_DIVIDER_BIG_ENDIAN)
40 iowrite32be(val, divider->reg);
41 else
42 writel(val, divider->reg);
43}
44
45static unsigned int _get_table_maxdiv(const struct clk_div_table *table,
46 u8 width)
47{
48 unsigned int maxdiv = 0, mask = clk_div_mask(width);
49 const struct clk_div_table *clkt;
50
51 for (clkt = table; clkt->div; clkt++)
52 if (clkt->div > maxdiv && clkt->val <= mask)
53 maxdiv = clkt->div;
54 return maxdiv;
55}
56
57static unsigned int _get_table_mindiv(const struct clk_div_table *table)
58{
59 unsigned int mindiv = UINT_MAX;
60 const struct clk_div_table *clkt;
61
62 for (clkt = table; clkt->div; clkt++)
63 if (clkt->div < mindiv)
64 mindiv = clkt->div;
65 return mindiv;
66}
67
68static unsigned int _get_maxdiv(const struct clk_div_table *table, u8 width,
69 unsigned long flags)
70{
71 if (flags & CLK_DIVIDER_ONE_BASED)
72 return clk_div_mask(width);
73 if (flags & CLK_DIVIDER_POWER_OF_TWO)
74 return 1 << clk_div_mask(width);
75 if (table)
76 return _get_table_maxdiv(table, width);
77 return clk_div_mask(width) + 1;
78}
79
80static unsigned int _get_table_div(const struct clk_div_table *table,
81 unsigned int val)
82{
83 const struct clk_div_table *clkt;
84
85 for (clkt = table; clkt->div; clkt++)
86 if (clkt->val == val)
87 return clkt->div;
88 return 0;
89}
90
91static unsigned int _get_div(const struct clk_div_table *table,
92 unsigned int val, unsigned long flags, u8 width)
93{
94 if (flags & CLK_DIVIDER_ONE_BASED)
95 return val;
96 if (flags & CLK_DIVIDER_POWER_OF_TWO)
97 return 1 << val;
98 if (flags & CLK_DIVIDER_MAX_AT_ZERO)
99 return val ? val : clk_div_mask(width) + 1;
100 if (table)
101 return _get_table_div(table, val);
102 return val + 1;
103}
104
105static unsigned int _get_table_val(const struct clk_div_table *table,
106 unsigned int div)
107{
108 const struct clk_div_table *clkt;
109
110 for (clkt = table; clkt->div; clkt++)
111 if (clkt->div == div)
112 return clkt->val;
113 return 0;
114}
115
116static unsigned int _get_val(const struct clk_div_table *table,
117 unsigned int div, unsigned long flags, u8 width)
118{
119 if (flags & CLK_DIVIDER_ONE_BASED)
120 return div;
121 if (flags & CLK_DIVIDER_POWER_OF_TWO)
122 return __ffs(div);
123 if (flags & CLK_DIVIDER_MAX_AT_ZERO)
124 return (div == clk_div_mask(width) + 1) ? 0 : div;
125 if (table)
126 return _get_table_val(table, div);
127 return div - 1;
128}
129
130unsigned long divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate,
131 unsigned int val,
132 const struct clk_div_table *table,
133 unsigned long flags, unsigned long width)
134{
135 unsigned int div;
136
137 div = _get_div(table, val, flags, width);
138 if (!div) {
139 WARN(!(flags & CLK_DIVIDER_ALLOW_ZERO),
140 "%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n",
141 clk_hw_get_name(hw));
142 return parent_rate;
143 }
144
145 return DIV_ROUND_UP_ULL((u64)parent_rate, div);
146}
147EXPORT_SYMBOL_GPL(divider_recalc_rate);
148
149static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
150 unsigned long parent_rate)
151{
152 struct clk_divider *divider = to_clk_divider(hw);
153 unsigned int val;
154
155 val = clk_div_readl(divider) >> divider->shift;
156 val &= clk_div_mask(divider->width);
157
158 return divider_recalc_rate(hw, parent_rate, val, divider->table,
159 divider->flags, divider->width);
160}
161
162static bool _is_valid_table_div(const struct clk_div_table *table,
163 unsigned int div)
164{
165 const struct clk_div_table *clkt;
166
167 for (clkt = table; clkt->div; clkt++)
168 if (clkt->div == div)
169 return true;
170 return false;
171}
172
173static bool _is_valid_div(const struct clk_div_table *table, unsigned int div,
174 unsigned long flags)
175{
176 if (flags & CLK_DIVIDER_POWER_OF_TWO)
177 return is_power_of_2(div);
178 if (table)
179 return _is_valid_table_div(table, div);
180 return true;
181}
182
183static int _round_up_table(const struct clk_div_table *table, int div)
184{
185 const struct clk_div_table *clkt;
186 int up = INT_MAX;
187
188 for (clkt = table; clkt->div; clkt++) {
189 if (clkt->div == div)
190 return clkt->div;
191 else if (clkt->div < div)
192 continue;
193
194 if ((clkt->div - div) < (up - div))
195 up = clkt->div;
196 }
197
198 return up;
199}
200
201static int _round_down_table(const struct clk_div_table *table, int div)
202{
203 const struct clk_div_table *clkt;
204 int down = _get_table_mindiv(table);
205
206 for (clkt = table; clkt->div; clkt++) {
207 if (clkt->div == div)
208 return clkt->div;
209 else if (clkt->div > div)
210 continue;
211
212 if ((div - clkt->div) < (div - down))
213 down = clkt->div;
214 }
215
216 return down;
217}
218
219static int _div_round_up(const struct clk_div_table *table,
220 unsigned long parent_rate, unsigned long rate,
221 unsigned long flags)
222{
223 int div = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
224
225 if (flags & CLK_DIVIDER_POWER_OF_TWO)
226 div = __roundup_pow_of_two(div);
227 if (table)
228 div = _round_up_table(table, div);
229
230 return div;
231}
232
233static int _div_round_closest(const struct clk_div_table *table,
234 unsigned long parent_rate, unsigned long rate,
235 unsigned long flags)
236{
237 int up, down;
238 unsigned long up_rate, down_rate;
239
240 up = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
241 down = parent_rate / rate;
242
243 if (flags & CLK_DIVIDER_POWER_OF_TWO) {
244 up = __roundup_pow_of_two(up);
245 down = __rounddown_pow_of_two(down);
246 } else if (table) {
247 up = _round_up_table(table, up);
248 down = _round_down_table(table, down);
249 }
250
251 up_rate = DIV_ROUND_UP_ULL((u64)parent_rate, up);
252 down_rate = DIV_ROUND_UP_ULL((u64)parent_rate, down);
253
254 return (rate - up_rate) <= (down_rate - rate) ? up : down;
255}
256
257static int _div_round(const struct clk_div_table *table,
258 unsigned long parent_rate, unsigned long rate,
259 unsigned long flags)
260{
261 if (flags & CLK_DIVIDER_ROUND_CLOSEST)
262 return _div_round_closest(table, parent_rate, rate, flags);
263
264 return _div_round_up(table, parent_rate, rate, flags);
265}
266
267static bool _is_best_div(unsigned long rate, unsigned long now,
268 unsigned long best, unsigned long flags)
269{
270 if (flags & CLK_DIVIDER_ROUND_CLOSEST)
271 return abs(rate - now) < abs(rate - best);
272
273 return now <= rate && now > best;
274}
275
276static int _next_div(const struct clk_div_table *table, int div,
277 unsigned long flags)
278{
279 div++;
280
281 if (flags & CLK_DIVIDER_POWER_OF_TWO)
282 return __roundup_pow_of_two(div);
283 if (table)
284 return _round_up_table(table, div);
285
286 return div;
287}
288
289static int clk_divider_bestdiv(struct clk_hw *hw, struct clk_hw *parent,
290 unsigned long rate,
291 unsigned long *best_parent_rate,
292 const struct clk_div_table *table, u8 width,
293 unsigned long flags)
294{
295 int i, bestdiv = 0;
296 unsigned long parent_rate, best = 0, now, maxdiv;
297 unsigned long parent_rate_saved = *best_parent_rate;
298
299 if (!rate)
300 rate = 1;
301
302 maxdiv = _get_maxdiv(table, width, flags);
303
304 if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
305 parent_rate = *best_parent_rate;
306 bestdiv = _div_round(table, parent_rate, rate, flags);
307 bestdiv = bestdiv == 0 ? 1 : bestdiv;
308 bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
309 return bestdiv;
310 }
311
312 /*
313 * The maximum divider we can use without overflowing
314 * unsigned long in rate * i below
315 */
316 maxdiv = min(ULONG_MAX / rate, maxdiv);
317
318 for (i = _next_div(table, 0, flags); i <= maxdiv;
319 i = _next_div(table, i, flags)) {
320 if (rate * i == parent_rate_saved) {
321 /*
322 * It's the most ideal case if the requested rate can be
323 * divided from parent clock without needing to change
324 * parent rate, so return the divider immediately.
325 */
326 *best_parent_rate = parent_rate_saved;
327 return i;
328 }
329 parent_rate = clk_hw_round_rate(parent, rate * i);
330 now = DIV_ROUND_UP_ULL((u64)parent_rate, i);
331 if (_is_best_div(rate, now, best, flags)) {
332 bestdiv = i;
333 best = now;
334 *best_parent_rate = parent_rate;
335 }
336 }
337
338 if (!bestdiv) {
339 bestdiv = _get_maxdiv(table, width, flags);
340 *best_parent_rate = clk_hw_round_rate(parent, 1);
341 }
342
343 return bestdiv;
344}
345
346int divider_determine_rate(struct clk_hw *hw, struct clk_rate_request *req,
347 const struct clk_div_table *table, u8 width,
348 unsigned long flags)
349{
350 int div;
351
352 div = clk_divider_bestdiv(hw, req->best_parent_hw, req->rate,
353 &req->best_parent_rate, table, width, flags);
354
355 req->rate = DIV_ROUND_UP_ULL((u64)req->best_parent_rate, div);
356
357 return 0;
358}
359EXPORT_SYMBOL_GPL(divider_determine_rate);
360
361int divider_ro_determine_rate(struct clk_hw *hw, struct clk_rate_request *req,
362 const struct clk_div_table *table, u8 width,
363 unsigned long flags, unsigned int val)
364{
365 int div;
366
367 div = _get_div(table, val, flags, width);
368
369 /* Even a read-only clock can propagate a rate change */
370 if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
371 if (!req->best_parent_hw)
372 return -EINVAL;
373
374 req->best_parent_rate = clk_hw_round_rate(req->best_parent_hw,
375 req->rate * div);
376 }
377
378 req->rate = DIV_ROUND_UP_ULL((u64)req->best_parent_rate, div);
379
380 return 0;
381}
382EXPORT_SYMBOL_GPL(divider_ro_determine_rate);
383
384long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
385 unsigned long rate, unsigned long *prate,
386 const struct clk_div_table *table,
387 u8 width, unsigned long flags)
388{
389 struct clk_rate_request req = {
390 .rate = rate,
391 .best_parent_rate = *prate,
392 .best_parent_hw = parent,
393 };
394 int ret;
395
396 ret = divider_determine_rate(hw, &req, table, width, flags);
397 if (ret)
398 return ret;
399
400 *prate = req.best_parent_rate;
401
402 return req.rate;
403}
404EXPORT_SYMBOL_GPL(divider_round_rate_parent);
405
406long divider_ro_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
407 unsigned long rate, unsigned long *prate,
408 const struct clk_div_table *table, u8 width,
409 unsigned long flags, unsigned int val)
410{
411 struct clk_rate_request req = {
412 .rate = rate,
413 .best_parent_rate = *prate,
414 .best_parent_hw = parent,
415 };
416 int ret;
417
418 ret = divider_ro_determine_rate(hw, &req, table, width, flags, val);
419 if (ret)
420 return ret;
421
422 *prate = req.best_parent_rate;
423
424 return req.rate;
425}
426EXPORT_SYMBOL_GPL(divider_ro_round_rate_parent);
427
428static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
429 unsigned long *prate)
430{
431 struct clk_divider *divider = to_clk_divider(hw);
432
433 /* if read only, just return current value */
434 if (divider->flags & CLK_DIVIDER_READ_ONLY) {
435 u32 val;
436
437 val = clk_div_readl(divider) >> divider->shift;
438 val &= clk_div_mask(divider->width);
439
440 return divider_ro_round_rate(hw, rate, prate, divider->table,
441 divider->width, divider->flags,
442 val);
443 }
444
445 return divider_round_rate(hw, rate, prate, divider->table,
446 divider->width, divider->flags);
447}
448
449int divider_get_val(unsigned long rate, unsigned long parent_rate,
450 const struct clk_div_table *table, u8 width,
451 unsigned long flags)
452{
453 unsigned int div, value;
454
455 div = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
456
457 if (!_is_valid_div(table, div, flags))
458 return -EINVAL;
459
460 value = _get_val(table, div, flags, width);
461
462 return min_t(unsigned int, value, clk_div_mask(width));
463}
464EXPORT_SYMBOL_GPL(divider_get_val);
465
466static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
467 unsigned long parent_rate)
468{
469 struct clk_divider *divider = to_clk_divider(hw);
470 int value;
471 unsigned long flags = 0;
472 u32 val;
473
474 value = divider_get_val(rate, parent_rate, divider->table,
475 divider->width, divider->flags);
476 if (value < 0)
477 return value;
478
479 if (divider->lock)
480 spin_lock_irqsave(divider->lock, flags);
481 else
482 __acquire(divider->lock);
483
484 if (divider->flags & CLK_DIVIDER_HIWORD_MASK) {
485 val = clk_div_mask(divider->width) << (divider->shift + 16);
486 } else {
487 val = clk_div_readl(divider);
488 val &= ~(clk_div_mask(divider->width) << divider->shift);
489 }
490 val |= (u32)value << divider->shift;
491 clk_div_writel(divider, val);
492
493 if (divider->lock)
494 spin_unlock_irqrestore(divider->lock, flags);
495 else
496 __release(divider->lock);
497
498 return 0;
499}
500
501const struct clk_ops clk_divider_ops = {
502 .recalc_rate = clk_divider_recalc_rate,
503 .round_rate = clk_divider_round_rate,
504 .set_rate = clk_divider_set_rate,
505};
506EXPORT_SYMBOL_GPL(clk_divider_ops);
507
508const struct clk_ops clk_divider_ro_ops = {
509 .recalc_rate = clk_divider_recalc_rate,
510 .round_rate = clk_divider_round_rate,
511};
512EXPORT_SYMBOL_GPL(clk_divider_ro_ops);
513
514struct clk_hw *__clk_hw_register_divider(struct device *dev,
515 struct device_node *np, const char *name,
516 const char *parent_name, const struct clk_hw *parent_hw,
517 const struct clk_parent_data *parent_data, unsigned long flags,
518 void __iomem *reg, u8 shift, u8 width, u8 clk_divider_flags,
519 const struct clk_div_table *table, spinlock_t *lock)
520{
521 struct clk_divider *div;
522 struct clk_hw *hw;
523 struct clk_init_data init = {};
524 int ret;
525
526 if (clk_divider_flags & CLK_DIVIDER_HIWORD_MASK) {
527 if (width + shift > 16) {
528 pr_warn("divider value exceeds LOWORD field\n");
529 return ERR_PTR(-EINVAL);
530 }
531 }
532
533 /* allocate the divider */
534 div = kzalloc(sizeof(*div), GFP_KERNEL);
535 if (!div)
536 return ERR_PTR(-ENOMEM);
537
538 init.name = name;
539 if (clk_divider_flags & CLK_DIVIDER_READ_ONLY)
540 init.ops = &clk_divider_ro_ops;
541 else
542 init.ops = &clk_divider_ops;
543 init.flags = flags;
544 init.parent_names = parent_name ? &parent_name : NULL;
545 init.parent_hws = parent_hw ? &parent_hw : NULL;
546 init.parent_data = parent_data;
547 if (parent_name || parent_hw || parent_data)
548 init.num_parents = 1;
549 else
550 init.num_parents = 0;
551
552 /* struct clk_divider assignments */
553 div->reg = reg;
554 div->shift = shift;
555 div->width = width;
556 div->flags = clk_divider_flags;
557 div->lock = lock;
558 div->hw.init = &init;
559 div->table = table;
560
561 /* register the clock */
562 hw = &div->hw;
563 ret = clk_hw_register(dev, hw);
564 if (ret) {
565 kfree(div);
566 hw = ERR_PTR(ret);
567 }
568
569 return hw;
570}
571EXPORT_SYMBOL_GPL(__clk_hw_register_divider);
572
573/**
574 * clk_register_divider_table - register a table based divider clock with
575 * the clock framework
576 * @dev: device registering this clock
577 * @name: name of this clock
578 * @parent_name: name of clock's parent
579 * @flags: framework-specific flags
580 * @reg: register address to adjust divider
581 * @shift: number of bits to shift the bitfield
582 * @width: width of the bitfield
583 * @clk_divider_flags: divider-specific flags for this clock
584 * @table: array of divider/value pairs ending with a div set to 0
585 * @lock: shared register lock for this clock
586 */
587struct clk *clk_register_divider_table(struct device *dev, const char *name,
588 const char *parent_name, unsigned long flags,
589 void __iomem *reg, u8 shift, u8 width,
590 u8 clk_divider_flags, const struct clk_div_table *table,
591 spinlock_t *lock)
592{
593 struct clk_hw *hw;
594
595 hw = __clk_hw_register_divider(dev, NULL, name, parent_name, NULL,
596 NULL, flags, reg, shift, width, clk_divider_flags,
597 table, lock);
598 if (IS_ERR(hw))
599 return ERR_CAST(hw);
600 return hw->clk;
601}
602EXPORT_SYMBOL_GPL(clk_register_divider_table);
603
604void clk_unregister_divider(struct clk *clk)
605{
606 struct clk_divider *div;
607 struct clk_hw *hw;
608
609 hw = __clk_get_hw(clk);
610 if (!hw)
611 return;
612
613 div = to_clk_divider(hw);
614
615 clk_unregister(clk);
616 kfree(div);
617}
618EXPORT_SYMBOL_GPL(clk_unregister_divider);
619
620/**
621 * clk_hw_unregister_divider - unregister a clk divider
622 * @hw: hardware-specific clock data to unregister
623 */
624void clk_hw_unregister_divider(struct clk_hw *hw)
625{
626 struct clk_divider *div;
627
628 div = to_clk_divider(hw);
629
630 clk_hw_unregister(hw);
631 kfree(div);
632}
633EXPORT_SYMBOL_GPL(clk_hw_unregister_divider);
634
635static void devm_clk_hw_release_divider(struct device *dev, void *res)
636{
637 clk_hw_unregister_divider(*(struct clk_hw **)res);
638}
639
640struct clk_hw *__devm_clk_hw_register_divider(struct device *dev,
641 struct device_node *np, const char *name,
642 const char *parent_name, const struct clk_hw *parent_hw,
643 const struct clk_parent_data *parent_data, unsigned long flags,
644 void __iomem *reg, u8 shift, u8 width, u8 clk_divider_flags,
645 const struct clk_div_table *table, spinlock_t *lock)
646{
647 struct clk_hw **ptr, *hw;
648
649 ptr = devres_alloc(devm_clk_hw_release_divider, sizeof(*ptr), GFP_KERNEL);
650 if (!ptr)
651 return ERR_PTR(-ENOMEM);
652
653 hw = __clk_hw_register_divider(dev, np, name, parent_name, parent_hw,
654 parent_data, flags, reg, shift, width,
655 clk_divider_flags, table, lock);
656
657 if (!IS_ERR(hw)) {
658 *ptr = hw;
659 devres_add(dev, ptr);
660 } else {
661 devres_free(ptr);
662 }
663
664 return hw;
665}
666EXPORT_SYMBOL_GPL(__devm_clk_hw_register_divider);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
4 * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
5 * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
6 *
7 * Adjustable divider clock implementation
8 */
9
10#include <linux/clk-provider.h>
11#include <linux/device.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/io.h>
15#include <linux/err.h>
16#include <linux/string.h>
17#include <linux/log2.h>
18
19/*
20 * DOC: basic adjustable divider clock that cannot gate
21 *
22 * Traits of this clock:
23 * prepare - clk_prepare only ensures that parents are prepared
24 * enable - clk_enable only ensures that parents are enabled
25 * rate - rate is adjustable. clk->rate = ceiling(parent->rate / divisor)
26 * parent - fixed parent. No clk_set_parent support
27 */
28
29static inline u32 clk_div_readl(struct clk_divider *divider)
30{
31 if (divider->flags & CLK_DIVIDER_BIG_ENDIAN)
32 return ioread32be(divider->reg);
33
34 return readl(divider->reg);
35}
36
37static inline void clk_div_writel(struct clk_divider *divider, u32 val)
38{
39 if (divider->flags & CLK_DIVIDER_BIG_ENDIAN)
40 iowrite32be(val, divider->reg);
41 else
42 writel(val, divider->reg);
43}
44
45static unsigned int _get_table_maxdiv(const struct clk_div_table *table,
46 u8 width)
47{
48 unsigned int maxdiv = 0, mask = clk_div_mask(width);
49 const struct clk_div_table *clkt;
50
51 for (clkt = table; clkt->div; clkt++)
52 if (clkt->div > maxdiv && clkt->val <= mask)
53 maxdiv = clkt->div;
54 return maxdiv;
55}
56
57static unsigned int _get_table_mindiv(const struct clk_div_table *table)
58{
59 unsigned int mindiv = UINT_MAX;
60 const struct clk_div_table *clkt;
61
62 for (clkt = table; clkt->div; clkt++)
63 if (clkt->div < mindiv)
64 mindiv = clkt->div;
65 return mindiv;
66}
67
68static unsigned int _get_maxdiv(const struct clk_div_table *table, u8 width,
69 unsigned long flags)
70{
71 if (flags & CLK_DIVIDER_ONE_BASED)
72 return clk_div_mask(width);
73 if (flags & CLK_DIVIDER_POWER_OF_TWO)
74 return 1 << clk_div_mask(width);
75 if (flags & CLK_DIVIDER_EVEN_INTEGERS)
76 return 2 * (clk_div_mask(width) + 1);
77 if (table)
78 return _get_table_maxdiv(table, width);
79 return clk_div_mask(width) + 1;
80}
81
82static unsigned int _get_table_div(const struct clk_div_table *table,
83 unsigned int val)
84{
85 const struct clk_div_table *clkt;
86
87 for (clkt = table; clkt->div; clkt++)
88 if (clkt->val == val)
89 return clkt->div;
90 return 0;
91}
92
93static unsigned int _get_div(const struct clk_div_table *table,
94 unsigned int val, unsigned long flags, u8 width)
95{
96 if (flags & CLK_DIVIDER_ONE_BASED)
97 return val;
98 if (flags & CLK_DIVIDER_POWER_OF_TWO)
99 return 1 << val;
100 if (flags & CLK_DIVIDER_MAX_AT_ZERO)
101 return val ? val : clk_div_mask(width) + 1;
102 if (flags & CLK_DIVIDER_EVEN_INTEGERS)
103 return 2 * (val + 1);
104 if (table)
105 return _get_table_div(table, val);
106 return val + 1;
107}
108
109static unsigned int _get_table_val(const struct clk_div_table *table,
110 unsigned int div)
111{
112 const struct clk_div_table *clkt;
113
114 for (clkt = table; clkt->div; clkt++)
115 if (clkt->div == div)
116 return clkt->val;
117 return 0;
118}
119
120static unsigned int _get_val(const struct clk_div_table *table,
121 unsigned int div, unsigned long flags, u8 width)
122{
123 if (flags & CLK_DIVIDER_ONE_BASED)
124 return div;
125 if (flags & CLK_DIVIDER_POWER_OF_TWO)
126 return __ffs(div);
127 if (flags & CLK_DIVIDER_MAX_AT_ZERO)
128 return (div == clk_div_mask(width) + 1) ? 0 : div;
129 if (flags & CLK_DIVIDER_EVEN_INTEGERS)
130 return (div >> 1) - 1;
131 if (table)
132 return _get_table_val(table, div);
133 return div - 1;
134}
135
136unsigned long divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate,
137 unsigned int val,
138 const struct clk_div_table *table,
139 unsigned long flags, unsigned long width)
140{
141 unsigned int div;
142
143 div = _get_div(table, val, flags, width);
144 if (!div) {
145 WARN(!(flags & CLK_DIVIDER_ALLOW_ZERO),
146 "%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n",
147 clk_hw_get_name(hw));
148 return parent_rate;
149 }
150
151 return DIV_ROUND_UP_ULL((u64)parent_rate, div);
152}
153EXPORT_SYMBOL_GPL(divider_recalc_rate);
154
155static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
156 unsigned long parent_rate)
157{
158 struct clk_divider *divider = to_clk_divider(hw);
159 unsigned int val;
160
161 val = clk_div_readl(divider) >> divider->shift;
162 val &= clk_div_mask(divider->width);
163
164 return divider_recalc_rate(hw, parent_rate, val, divider->table,
165 divider->flags, divider->width);
166}
167
168static bool _is_valid_table_div(const struct clk_div_table *table,
169 unsigned int div)
170{
171 const struct clk_div_table *clkt;
172
173 for (clkt = table; clkt->div; clkt++)
174 if (clkt->div == div)
175 return true;
176 return false;
177}
178
179static bool _is_valid_div(const struct clk_div_table *table, unsigned int div,
180 unsigned long flags)
181{
182 if (flags & CLK_DIVIDER_POWER_OF_TWO)
183 return is_power_of_2(div);
184 if (table)
185 return _is_valid_table_div(table, div);
186 return true;
187}
188
189static int _round_up_table(const struct clk_div_table *table, int div)
190{
191 const struct clk_div_table *clkt;
192 int up = INT_MAX;
193
194 for (clkt = table; clkt->div; clkt++) {
195 if (clkt->div == div)
196 return clkt->div;
197 else if (clkt->div < div)
198 continue;
199
200 if ((clkt->div - div) < (up - div))
201 up = clkt->div;
202 }
203
204 return up;
205}
206
207static int _round_down_table(const struct clk_div_table *table, int div)
208{
209 const struct clk_div_table *clkt;
210 int down = _get_table_mindiv(table);
211
212 for (clkt = table; clkt->div; clkt++) {
213 if (clkt->div == div)
214 return clkt->div;
215 else if (clkt->div > div)
216 continue;
217
218 if ((div - clkt->div) < (div - down))
219 down = clkt->div;
220 }
221
222 return down;
223}
224
225static int _div_round_up(const struct clk_div_table *table,
226 unsigned long parent_rate, unsigned long rate,
227 unsigned long flags)
228{
229 int div = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
230
231 if (flags & CLK_DIVIDER_POWER_OF_TWO)
232 div = __roundup_pow_of_two(div);
233 if (table)
234 div = _round_up_table(table, div);
235
236 return div;
237}
238
239static int _div_round_closest(const struct clk_div_table *table,
240 unsigned long parent_rate, unsigned long rate,
241 unsigned long flags)
242{
243 int up, down;
244 unsigned long up_rate, down_rate;
245
246 up = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
247 down = parent_rate / rate;
248
249 if (flags & CLK_DIVIDER_POWER_OF_TWO) {
250 up = __roundup_pow_of_two(up);
251 down = __rounddown_pow_of_two(down);
252 } else if (table) {
253 up = _round_up_table(table, up);
254 down = _round_down_table(table, down);
255 }
256
257 up_rate = DIV_ROUND_UP_ULL((u64)parent_rate, up);
258 down_rate = DIV_ROUND_UP_ULL((u64)parent_rate, down);
259
260 return (rate - up_rate) <= (down_rate - rate) ? up : down;
261}
262
263static int _div_round(const struct clk_div_table *table,
264 unsigned long parent_rate, unsigned long rate,
265 unsigned long flags)
266{
267 if (flags & CLK_DIVIDER_ROUND_CLOSEST)
268 return _div_round_closest(table, parent_rate, rate, flags);
269
270 return _div_round_up(table, parent_rate, rate, flags);
271}
272
273static bool _is_best_div(unsigned long rate, unsigned long now,
274 unsigned long best, unsigned long flags)
275{
276 if (flags & CLK_DIVIDER_ROUND_CLOSEST)
277 return abs(rate - now) < abs(rate - best);
278
279 return now <= rate && now > best;
280}
281
282static int _next_div(const struct clk_div_table *table, int div,
283 unsigned long flags)
284{
285 div++;
286
287 if (flags & CLK_DIVIDER_POWER_OF_TWO)
288 return __roundup_pow_of_two(div);
289 if (table)
290 return _round_up_table(table, div);
291
292 return div;
293}
294
295static int clk_divider_bestdiv(struct clk_hw *hw, struct clk_hw *parent,
296 unsigned long rate,
297 unsigned long *best_parent_rate,
298 const struct clk_div_table *table, u8 width,
299 unsigned long flags)
300{
301 int i, bestdiv = 0;
302 unsigned long parent_rate, best = 0, now, maxdiv;
303 unsigned long parent_rate_saved = *best_parent_rate;
304
305 if (!rate)
306 rate = 1;
307
308 maxdiv = _get_maxdiv(table, width, flags);
309
310 if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
311 parent_rate = *best_parent_rate;
312 bestdiv = _div_round(table, parent_rate, rate, flags);
313 bestdiv = bestdiv == 0 ? 1 : bestdiv;
314 bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
315 return bestdiv;
316 }
317
318 /*
319 * The maximum divider we can use without overflowing
320 * unsigned long in rate * i below
321 */
322 maxdiv = min(ULONG_MAX / rate, maxdiv);
323
324 for (i = _next_div(table, 0, flags); i <= maxdiv;
325 i = _next_div(table, i, flags)) {
326 if (rate * i == parent_rate_saved) {
327 /*
328 * It's the most ideal case if the requested rate can be
329 * divided from parent clock without needing to change
330 * parent rate, so return the divider immediately.
331 */
332 *best_parent_rate = parent_rate_saved;
333 return i;
334 }
335 parent_rate = clk_hw_round_rate(parent, rate * i);
336 now = DIV_ROUND_UP_ULL((u64)parent_rate, i);
337 if (_is_best_div(rate, now, best, flags)) {
338 bestdiv = i;
339 best = now;
340 *best_parent_rate = parent_rate;
341 }
342 }
343
344 if (!bestdiv) {
345 bestdiv = _get_maxdiv(table, width, flags);
346 *best_parent_rate = clk_hw_round_rate(parent, 1);
347 }
348
349 return bestdiv;
350}
351
352int divider_determine_rate(struct clk_hw *hw, struct clk_rate_request *req,
353 const struct clk_div_table *table, u8 width,
354 unsigned long flags)
355{
356 int div;
357
358 div = clk_divider_bestdiv(hw, req->best_parent_hw, req->rate,
359 &req->best_parent_rate, table, width, flags);
360
361 req->rate = DIV_ROUND_UP_ULL((u64)req->best_parent_rate, div);
362
363 return 0;
364}
365EXPORT_SYMBOL_GPL(divider_determine_rate);
366
367int divider_ro_determine_rate(struct clk_hw *hw, struct clk_rate_request *req,
368 const struct clk_div_table *table, u8 width,
369 unsigned long flags, unsigned int val)
370{
371 int div;
372
373 div = _get_div(table, val, flags, width);
374
375 /* Even a read-only clock can propagate a rate change */
376 if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
377 if (!req->best_parent_hw)
378 return -EINVAL;
379
380 req->best_parent_rate = clk_hw_round_rate(req->best_parent_hw,
381 req->rate * div);
382 }
383
384 req->rate = DIV_ROUND_UP_ULL((u64)req->best_parent_rate, div);
385
386 return 0;
387}
388EXPORT_SYMBOL_GPL(divider_ro_determine_rate);
389
390long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
391 unsigned long rate, unsigned long *prate,
392 const struct clk_div_table *table,
393 u8 width, unsigned long flags)
394{
395 struct clk_rate_request req;
396 int ret;
397
398 clk_hw_init_rate_request(hw, &req, rate);
399 req.best_parent_rate = *prate;
400 req.best_parent_hw = parent;
401
402 ret = divider_determine_rate(hw, &req, table, width, flags);
403 if (ret)
404 return ret;
405
406 *prate = req.best_parent_rate;
407
408 return req.rate;
409}
410EXPORT_SYMBOL_GPL(divider_round_rate_parent);
411
412long divider_ro_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
413 unsigned long rate, unsigned long *prate,
414 const struct clk_div_table *table, u8 width,
415 unsigned long flags, unsigned int val)
416{
417 struct clk_rate_request req;
418 int ret;
419
420 clk_hw_init_rate_request(hw, &req, rate);
421 req.best_parent_rate = *prate;
422 req.best_parent_hw = parent;
423
424 ret = divider_ro_determine_rate(hw, &req, table, width, flags, val);
425 if (ret)
426 return ret;
427
428 *prate = req.best_parent_rate;
429
430 return req.rate;
431}
432EXPORT_SYMBOL_GPL(divider_ro_round_rate_parent);
433
434static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
435 unsigned long *prate)
436{
437 struct clk_divider *divider = to_clk_divider(hw);
438
439 /* if read only, just return current value */
440 if (divider->flags & CLK_DIVIDER_READ_ONLY) {
441 u32 val;
442
443 val = clk_div_readl(divider) >> divider->shift;
444 val &= clk_div_mask(divider->width);
445
446 return divider_ro_round_rate(hw, rate, prate, divider->table,
447 divider->width, divider->flags,
448 val);
449 }
450
451 return divider_round_rate(hw, rate, prate, divider->table,
452 divider->width, divider->flags);
453}
454
455static int clk_divider_determine_rate(struct clk_hw *hw,
456 struct clk_rate_request *req)
457{
458 struct clk_divider *divider = to_clk_divider(hw);
459
460 /* if read only, just return current value */
461 if (divider->flags & CLK_DIVIDER_READ_ONLY) {
462 u32 val;
463
464 val = clk_div_readl(divider) >> divider->shift;
465 val &= clk_div_mask(divider->width);
466
467 return divider_ro_determine_rate(hw, req, divider->table,
468 divider->width,
469 divider->flags, val);
470 }
471
472 return divider_determine_rate(hw, req, divider->table, divider->width,
473 divider->flags);
474}
475
476int divider_get_val(unsigned long rate, unsigned long parent_rate,
477 const struct clk_div_table *table, u8 width,
478 unsigned long flags)
479{
480 unsigned int div, value;
481
482 div = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
483
484 if (!_is_valid_div(table, div, flags))
485 return -EINVAL;
486
487 value = _get_val(table, div, flags, width);
488
489 return min_t(unsigned int, value, clk_div_mask(width));
490}
491EXPORT_SYMBOL_GPL(divider_get_val);
492
493static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
494 unsigned long parent_rate)
495{
496 struct clk_divider *divider = to_clk_divider(hw);
497 int value;
498 unsigned long flags = 0;
499 u32 val;
500
501 value = divider_get_val(rate, parent_rate, divider->table,
502 divider->width, divider->flags);
503 if (value < 0)
504 return value;
505
506 if (divider->lock)
507 spin_lock_irqsave(divider->lock, flags);
508 else
509 __acquire(divider->lock);
510
511 if (divider->flags & CLK_DIVIDER_HIWORD_MASK) {
512 val = clk_div_mask(divider->width) << (divider->shift + 16);
513 } else {
514 val = clk_div_readl(divider);
515 val &= ~(clk_div_mask(divider->width) << divider->shift);
516 }
517 val |= (u32)value << divider->shift;
518 clk_div_writel(divider, val);
519
520 if (divider->lock)
521 spin_unlock_irqrestore(divider->lock, flags);
522 else
523 __release(divider->lock);
524
525 return 0;
526}
527
528const struct clk_ops clk_divider_ops = {
529 .recalc_rate = clk_divider_recalc_rate,
530 .round_rate = clk_divider_round_rate,
531 .determine_rate = clk_divider_determine_rate,
532 .set_rate = clk_divider_set_rate,
533};
534EXPORT_SYMBOL_GPL(clk_divider_ops);
535
536const struct clk_ops clk_divider_ro_ops = {
537 .recalc_rate = clk_divider_recalc_rate,
538 .round_rate = clk_divider_round_rate,
539 .determine_rate = clk_divider_determine_rate,
540};
541EXPORT_SYMBOL_GPL(clk_divider_ro_ops);
542
543struct clk_hw *__clk_hw_register_divider(struct device *dev,
544 struct device_node *np, const char *name,
545 const char *parent_name, const struct clk_hw *parent_hw,
546 const struct clk_parent_data *parent_data, unsigned long flags,
547 void __iomem *reg, u8 shift, u8 width,
548 unsigned long clk_divider_flags,
549 const struct clk_div_table *table, spinlock_t *lock)
550{
551 struct clk_divider *div;
552 struct clk_hw *hw;
553 struct clk_init_data init = {};
554 int ret;
555
556 if (clk_divider_flags & CLK_DIVIDER_HIWORD_MASK) {
557 if (width + shift > 16) {
558 pr_warn("divider value exceeds LOWORD field\n");
559 return ERR_PTR(-EINVAL);
560 }
561 }
562
563 /* allocate the divider */
564 div = kzalloc(sizeof(*div), GFP_KERNEL);
565 if (!div)
566 return ERR_PTR(-ENOMEM);
567
568 init.name = name;
569 if (clk_divider_flags & CLK_DIVIDER_READ_ONLY)
570 init.ops = &clk_divider_ro_ops;
571 else
572 init.ops = &clk_divider_ops;
573 init.flags = flags;
574 init.parent_names = parent_name ? &parent_name : NULL;
575 init.parent_hws = parent_hw ? &parent_hw : NULL;
576 init.parent_data = parent_data;
577 if (parent_name || parent_hw || parent_data)
578 init.num_parents = 1;
579 else
580 init.num_parents = 0;
581
582 /* struct clk_divider assignments */
583 div->reg = reg;
584 div->shift = shift;
585 div->width = width;
586 div->flags = clk_divider_flags;
587 div->lock = lock;
588 div->hw.init = &init;
589 div->table = table;
590
591 /* register the clock */
592 hw = &div->hw;
593 ret = clk_hw_register(dev, hw);
594 if (ret) {
595 kfree(div);
596 hw = ERR_PTR(ret);
597 }
598
599 return hw;
600}
601EXPORT_SYMBOL_GPL(__clk_hw_register_divider);
602
603/**
604 * clk_register_divider_table - register a table based divider clock with
605 * the clock framework
606 * @dev: device registering this clock
607 * @name: name of this clock
608 * @parent_name: name of clock's parent
609 * @flags: framework-specific flags
610 * @reg: register address to adjust divider
611 * @shift: number of bits to shift the bitfield
612 * @width: width of the bitfield
613 * @clk_divider_flags: divider-specific flags for this clock
614 * @table: array of divider/value pairs ending with a div set to 0
615 * @lock: shared register lock for this clock
616 */
617struct clk *clk_register_divider_table(struct device *dev, const char *name,
618 const char *parent_name, unsigned long flags,
619 void __iomem *reg, u8 shift, u8 width,
620 unsigned long clk_divider_flags,
621 const struct clk_div_table *table, spinlock_t *lock)
622{
623 struct clk_hw *hw;
624
625 hw = __clk_hw_register_divider(dev, NULL, name, parent_name, NULL,
626 NULL, flags, reg, shift, width, clk_divider_flags,
627 table, lock);
628 if (IS_ERR(hw))
629 return ERR_CAST(hw);
630 return hw->clk;
631}
632EXPORT_SYMBOL_GPL(clk_register_divider_table);
633
634void clk_unregister_divider(struct clk *clk)
635{
636 struct clk_divider *div;
637 struct clk_hw *hw;
638
639 hw = __clk_get_hw(clk);
640 if (!hw)
641 return;
642
643 div = to_clk_divider(hw);
644
645 clk_unregister(clk);
646 kfree(div);
647}
648EXPORT_SYMBOL_GPL(clk_unregister_divider);
649
650/**
651 * clk_hw_unregister_divider - unregister a clk divider
652 * @hw: hardware-specific clock data to unregister
653 */
654void clk_hw_unregister_divider(struct clk_hw *hw)
655{
656 struct clk_divider *div;
657
658 div = to_clk_divider(hw);
659
660 clk_hw_unregister(hw);
661 kfree(div);
662}
663EXPORT_SYMBOL_GPL(clk_hw_unregister_divider);
664
665static void devm_clk_hw_release_divider(struct device *dev, void *res)
666{
667 clk_hw_unregister_divider(*(struct clk_hw **)res);
668}
669
670struct clk_hw *__devm_clk_hw_register_divider(struct device *dev,
671 struct device_node *np, const char *name,
672 const char *parent_name, const struct clk_hw *parent_hw,
673 const struct clk_parent_data *parent_data, unsigned long flags,
674 void __iomem *reg, u8 shift, u8 width,
675 unsigned long clk_divider_flags,
676 const struct clk_div_table *table, spinlock_t *lock)
677{
678 struct clk_hw **ptr, *hw;
679
680 ptr = devres_alloc(devm_clk_hw_release_divider, sizeof(*ptr), GFP_KERNEL);
681 if (!ptr)
682 return ERR_PTR(-ENOMEM);
683
684 hw = __clk_hw_register_divider(dev, np, name, parent_name, parent_hw,
685 parent_data, flags, reg, shift, width,
686 clk_divider_flags, table, lock);
687
688 if (!IS_ERR(hw)) {
689 *ptr = hw;
690 devres_add(dev, ptr);
691 } else {
692 devres_free(ptr);
693 }
694
695 return hw;
696}
697EXPORT_SYMBOL_GPL(__devm_clk_hw_register_divider);