1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) STMicroelectronics 2016
*
* Author: Gerald Baeza <gerald.baeza@st.com>
*
* Inspired by timer-stm32.c from Maxime Coquelin
* pwm-atmel.c from Bo Shen
*/
#include <linux/bitfield.h>
#include <linux/mfd/stm32-timers.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#define CCMR_CHANNEL_SHIFT 8
#define CCMR_CHANNEL_MASK 0xFF
#define MAX_BREAKINPUT 2
struct stm32_breakinput {
u32 index;
u32 level;
u32 filter;
};
struct stm32_pwm {
struct pwm_chip chip;
struct mutex lock; /* protect pwm config/enable */
struct clk *clk;
struct regmap *regmap;
u32 max_arr;
bool have_complementary_output;
struct stm32_breakinput breakinputs[MAX_BREAKINPUT];
unsigned int num_breakinputs;
u32 capture[4] ____cacheline_aligned; /* DMA'able buffer */
};
static inline struct stm32_pwm *to_stm32_pwm_dev(struct pwm_chip *chip)
{
return container_of(chip, struct stm32_pwm, chip);
}
static u32 active_channels(struct stm32_pwm *dev)
{
u32 ccer;
regmap_read(dev->regmap, TIM_CCER, &ccer);
return ccer & TIM_CCER_CCXE;
}
static int write_ccrx(struct stm32_pwm *dev, int ch, u32 value)
{
switch (ch) {
case 0:
return regmap_write(dev->regmap, TIM_CCR1, value);
case 1:
return regmap_write(dev->regmap, TIM_CCR2, value);
case 2:
return regmap_write(dev->regmap, TIM_CCR3, value);
case 3:
return regmap_write(dev->regmap, TIM_CCR4, value);
}
return -EINVAL;
}
#define TIM_CCER_CC12P (TIM_CCER_CC1P | TIM_CCER_CC2P)
#define TIM_CCER_CC12E (TIM_CCER_CC1E | TIM_CCER_CC2E)
#define TIM_CCER_CC34P (TIM_CCER_CC3P | TIM_CCER_CC4P)
#define TIM_CCER_CC34E (TIM_CCER_CC3E | TIM_CCER_CC4E)
/*
* Capture using PWM input mode:
* ___ ___
* TI[1, 2, 3 or 4]: ........._| |________|
* ^0 ^1 ^2
* . . .
* . . XXXXX
* . . XXXXX |
* . XXXXX . |
* XXXXX . . |
* COUNTER: ______XXXXX . . . |_XXX
* start^ . . . ^stop
* . . . .
* v v . v
* v
* CCR1/CCR3: tx..........t0...........t2
* CCR2/CCR4: tx..............t1.........
*
* DMA burst transfer: | |
* v v
* DMA buffer: { t0, tx } { t2, t1 }
* DMA done: ^
*
* 0: IC1/3 snapchot on rising edge: counter value -> CCR1/CCR3
* + DMA transfer CCR[1/3] & CCR[2/4] values (t0, tx: doesn't care)
* 1: IC2/4 snapchot on falling edge: counter value -> CCR2/CCR4
* 2: IC1/3 snapchot on rising edge: counter value -> CCR1/CCR3
* + DMA transfer CCR[1/3] & CCR[2/4] values (t2, t1)
*
* DMA done, compute:
* - Period = t2 - t0
* - Duty cycle = t1 - t0
*/
static int stm32_pwm_raw_capture(struct stm32_pwm *priv, struct pwm_device *pwm,
unsigned long tmo_ms, u32 *raw_prd,
u32 *raw_dty)
{
struct device *parent = priv->chip.dev->parent;
enum stm32_timers_dmas dma_id;
u32 ccen, ccr;
int ret;
/* Ensure registers have been updated, enable counter and capture */
regmap_set_bits(priv->regmap, TIM_EGR, TIM_EGR_UG);
regmap_set_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
/* Use cc1 or cc3 DMA resp for PWM input channels 1 & 2 or 3 & 4 */
dma_id = pwm->hwpwm < 2 ? STM32_TIMERS_DMA_CH1 : STM32_TIMERS_DMA_CH3;
ccen = pwm->hwpwm < 2 ? TIM_CCER_CC12E : TIM_CCER_CC34E;
ccr = pwm->hwpwm < 2 ? TIM_CCR1 : TIM_CCR3;
regmap_set_bits(priv->regmap, TIM_CCER, ccen);
/*
* Timer DMA burst mode. Request 2 registers, 2 bursts, to get both
* CCR1 & CCR2 (or CCR3 & CCR4) on each capture event.
* We'll get two capture snapchots: { CCR1, CCR2 }, { CCR1, CCR2 }
* or { CCR3, CCR4 }, { CCR3, CCR4 }
*/
ret = stm32_timers_dma_burst_read(parent, priv->capture, dma_id, ccr, 2,
2, tmo_ms);
if (ret)
goto stop;
/* Period: t2 - t0 (take care of counter overflow) */
if (priv->capture[0] <= priv->capture[2])
*raw_prd = priv->capture[2] - priv->capture[0];
else
*raw_prd = priv->max_arr - priv->capture[0] + priv->capture[2];
/* Duty cycle capture requires at least two capture units */
if (pwm->chip->npwm < 2)
*raw_dty = 0;
else if (priv->capture[0] <= priv->capture[3])
*raw_dty = priv->capture[3] - priv->capture[0];
else
*raw_dty = priv->max_arr - priv->capture[0] + priv->capture[3];
if (*raw_dty > *raw_prd) {
/*
* Race beetween PWM input and DMA: it may happen
* falling edge triggers new capture on TI2/4 before DMA
* had a chance to read CCR2/4. It means capture[1]
* contains period + duty_cycle. So, subtract period.
*/
*raw_dty -= *raw_prd;
}
stop:
regmap_clear_bits(priv->regmap, TIM_CCER, ccen);
regmap_clear_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
return ret;
}
static int stm32_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
struct pwm_capture *result, unsigned long tmo_ms)
{
struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
unsigned long long prd, div, dty;
unsigned long rate;
unsigned int psc = 0, icpsc, scale;
u32 raw_prd = 0, raw_dty = 0;
int ret = 0;
mutex_lock(&priv->lock);
if (active_channels(priv)) {
ret = -EBUSY;
goto unlock;
}
ret = clk_enable(priv->clk);
if (ret) {
dev_err(priv->chip.dev, "failed to enable counter clock\n");
goto unlock;
}
rate = clk_get_rate(priv->clk);
if (!rate) {
ret = -EINVAL;
goto clk_dis;
}
/* prescaler: fit timeout window provided by upper layer */
div = (unsigned long long)rate * (unsigned long long)tmo_ms;
do_div(div, MSEC_PER_SEC);
prd = div;
while ((div > priv->max_arr) && (psc < MAX_TIM_PSC)) {
psc++;
div = prd;
do_div(div, psc + 1);
}
regmap_write(priv->regmap, TIM_ARR, priv->max_arr);
regmap_write(priv->regmap, TIM_PSC, psc);
/* Reset input selector to its default input and disable slave mode */
regmap_write(priv->regmap, TIM_TISEL, 0x0);
regmap_write(priv->regmap, TIM_SMCR, 0x0);
/* Map TI1 or TI2 PWM input to IC1 & IC2 (or TI3/4 to IC3 & IC4) */
regmap_update_bits(priv->regmap,
pwm->hwpwm < 2 ? TIM_CCMR1 : TIM_CCMR2,
TIM_CCMR_CC1S | TIM_CCMR_CC2S, pwm->hwpwm & 0x1 ?
TIM_CCMR_CC1S_TI2 | TIM_CCMR_CC2S_TI2 :
TIM_CCMR_CC1S_TI1 | TIM_CCMR_CC2S_TI1);
/* Capture period on IC1/3 rising edge, duty cycle on IC2/4 falling. */
regmap_update_bits(priv->regmap, TIM_CCER, pwm->hwpwm < 2 ?
TIM_CCER_CC12P : TIM_CCER_CC34P, pwm->hwpwm < 2 ?
TIM_CCER_CC2P : TIM_CCER_CC4P);
ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd, &raw_dty);
if (ret)
goto stop;
/*
* Got a capture. Try to improve accuracy at high rates:
* - decrease counter clock prescaler, scale up to max rate.
* - use input prescaler, capture once every /2 /4 or /8 edges.
*/
if (raw_prd) {
u32 max_arr = priv->max_arr - 0x1000; /* arbitrary margin */
scale = max_arr / min(max_arr, raw_prd);
} else {
scale = priv->max_arr; /* bellow resolution, use max scale */
}
if (psc && scale > 1) {
/* 2nd measure with new scale */
psc /= scale;
regmap_write(priv->regmap, TIM_PSC, psc);
ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd,
&raw_dty);
if (ret)
goto stop;
}
/* Compute intermediate period not to exceed timeout at low rates */
prd = (unsigned long long)raw_prd * (psc + 1) * NSEC_PER_SEC;
do_div(prd, rate);
for (icpsc = 0; icpsc < MAX_TIM_ICPSC ; icpsc++) {
/* input prescaler: also keep arbitrary margin */
if (raw_prd >= (priv->max_arr - 0x1000) >> (icpsc + 1))
break;
if (prd >= (tmo_ms * NSEC_PER_MSEC) >> (icpsc + 2))
break;
}
if (!icpsc)
goto done;
/* Last chance to improve period accuracy, using input prescaler */
regmap_update_bits(priv->regmap,
pwm->hwpwm < 2 ? TIM_CCMR1 : TIM_CCMR2,
TIM_CCMR_IC1PSC | TIM_CCMR_IC2PSC,
FIELD_PREP(TIM_CCMR_IC1PSC, icpsc) |
FIELD_PREP(TIM_CCMR_IC2PSC, icpsc));
ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd, &raw_dty);
if (ret)
goto stop;
if (raw_dty >= (raw_prd >> icpsc)) {
/*
* We may fall here using input prescaler, when input
* capture starts on high side (before falling edge).
* Example with icpsc to capture on each 4 events:
*
* start 1st capture 2nd capture
* v v v
* ___ _____ _____ _____ _____ ____
* TI1..4 |__| |__| |__| |__| |__|
* v v . . . . . v v
* icpsc1/3: . 0 . 1 . 2 . 3 . 0
* icpsc2/4: 0 1 2 3 0
* v v v v
* CCR1/3 ......t0..............................t2
* CCR2/4 ..t1..............................t1'...
* . . .
* Capture0: .<----------------------------->.
* Capture1: .<-------------------------->. .
* . . .
* Period: .<------> . .
* Low side: .<>.
*
* Result:
* - Period = Capture0 / icpsc
* - Duty = Period - Low side = Period - (Capture0 - Capture1)
*/
raw_dty = (raw_prd >> icpsc) - (raw_prd - raw_dty);
}
done:
prd = (unsigned long long)raw_prd * (psc + 1) * NSEC_PER_SEC;
result->period = DIV_ROUND_UP_ULL(prd, rate << icpsc);
dty = (unsigned long long)raw_dty * (psc + 1) * NSEC_PER_SEC;
result->duty_cycle = DIV_ROUND_UP_ULL(dty, rate);
stop:
regmap_write(priv->regmap, TIM_CCER, 0);
regmap_write(priv->regmap, pwm->hwpwm < 2 ? TIM_CCMR1 : TIM_CCMR2, 0);
regmap_write(priv->regmap, TIM_PSC, 0);
clk_dis:
clk_disable(priv->clk);
unlock:
mutex_unlock(&priv->lock);
return ret;
}
static int stm32_pwm_config(struct stm32_pwm *priv, int ch,
int duty_ns, int period_ns)
{
unsigned long long prd, div, dty;
unsigned int prescaler = 0;
u32 ccmr, mask, shift;
/* Period and prescaler values depends on clock rate */
div = (unsigned long long)clk_get_rate(priv->clk) * period_ns;
do_div(div, NSEC_PER_SEC);
prd = div;
while (div > priv->max_arr) {
prescaler++;
div = prd;
do_div(div, prescaler + 1);
}
prd = div;
if (prescaler > MAX_TIM_PSC)
return -EINVAL;
/*
* All channels share the same prescaler and counter so when two
* channels are active at the same time we can't change them
*/
if (active_channels(priv) & ~(1 << ch * 4)) {
u32 psc, arr;
regmap_read(priv->regmap, TIM_PSC, &psc);
regmap_read(priv->regmap, TIM_ARR, &arr);
if ((psc != prescaler) || (arr != prd - 1))
return -EBUSY;
}
regmap_write(priv->regmap, TIM_PSC, prescaler);
regmap_write(priv->regmap, TIM_ARR, prd - 1);
regmap_set_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE);
/* Calculate the duty cycles */
dty = prd * duty_ns;
do_div(dty, period_ns);
write_ccrx(priv, ch, dty);
/* Configure output mode */
shift = (ch & 0x1) * CCMR_CHANNEL_SHIFT;
ccmr = (TIM_CCMR_PE | TIM_CCMR_M1) << shift;
mask = CCMR_CHANNEL_MASK << shift;
if (ch < 2)
regmap_update_bits(priv->regmap, TIM_CCMR1, mask, ccmr);
else
regmap_update_bits(priv->regmap, TIM_CCMR2, mask, ccmr);
regmap_set_bits(priv->regmap, TIM_BDTR, TIM_BDTR_MOE);
return 0;
}
static int stm32_pwm_set_polarity(struct stm32_pwm *priv, int ch,
enum pwm_polarity polarity)
{
u32 mask;
mask = TIM_CCER_CC1P << (ch * 4);
if (priv->have_complementary_output)
mask |= TIM_CCER_CC1NP << (ch * 4);
regmap_update_bits(priv->regmap, TIM_CCER, mask,
polarity == PWM_POLARITY_NORMAL ? 0 : mask);
return 0;
}
static int stm32_pwm_enable(struct stm32_pwm *priv, int ch)
{
u32 mask;
int ret;
ret = clk_enable(priv->clk);
if (ret)
return ret;
/* Enable channel */
mask = TIM_CCER_CC1E << (ch * 4);
if (priv->have_complementary_output)
mask |= TIM_CCER_CC1NE << (ch * 4);
regmap_set_bits(priv->regmap, TIM_CCER, mask);
/* Make sure that registers are updated */
regmap_set_bits(priv->regmap, TIM_EGR, TIM_EGR_UG);
/* Enable controller */
regmap_set_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
return 0;
}
static void stm32_pwm_disable(struct stm32_pwm *priv, int ch)
{
u32 mask;
/* Disable channel */
mask = TIM_CCER_CC1E << (ch * 4);
if (priv->have_complementary_output)
mask |= TIM_CCER_CC1NE << (ch * 4);
regmap_clear_bits(priv->regmap, TIM_CCER, mask);
/* When all channels are disabled, we can disable the controller */
if (!active_channels(priv))
regmap_clear_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
clk_disable(priv->clk);
}
static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
bool enabled;
struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
int ret;
enabled = pwm->state.enabled;
if (enabled && !state->enabled) {
stm32_pwm_disable(priv, pwm->hwpwm);
return 0;
}
if (state->polarity != pwm->state.polarity)
stm32_pwm_set_polarity(priv, pwm->hwpwm, state->polarity);
ret = stm32_pwm_config(priv, pwm->hwpwm,
state->duty_cycle, state->period);
if (ret)
return ret;
if (!enabled && state->enabled)
ret = stm32_pwm_enable(priv, pwm->hwpwm);
return ret;
}
static int stm32_pwm_apply_locked(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
int ret;
/* protect common prescaler for all active channels */
mutex_lock(&priv->lock);
ret = stm32_pwm_apply(chip, pwm, state);
mutex_unlock(&priv->lock);
return ret;
}
static const struct pwm_ops stm32pwm_ops = {
.owner = THIS_MODULE,
.apply = stm32_pwm_apply_locked,
.capture = IS_ENABLED(CONFIG_DMA_ENGINE) ? stm32_pwm_capture : NULL,
};
static int stm32_pwm_set_breakinput(struct stm32_pwm *priv,
const struct stm32_breakinput *bi)
{
u32 shift = TIM_BDTR_BKF_SHIFT(bi->index);
u32 bke = TIM_BDTR_BKE(bi->index);
u32 bkp = TIM_BDTR_BKP(bi->index);
u32 bkf = TIM_BDTR_BKF(bi->index);
u32 mask = bkf | bkp | bke;
u32 bdtr;
bdtr = (bi->filter & TIM_BDTR_BKF_MASK) << shift | bke;
if (bi->level)
bdtr |= bkp;
regmap_update_bits(priv->regmap, TIM_BDTR, mask, bdtr);
regmap_read(priv->regmap, TIM_BDTR, &bdtr);
return (bdtr & bke) ? 0 : -EINVAL;
}
static int stm32_pwm_apply_breakinputs(struct stm32_pwm *priv)
{
unsigned int i;
int ret;
for (i = 0; i < priv->num_breakinputs; i++) {
ret = stm32_pwm_set_breakinput(priv, &priv->breakinputs[i]);
if (ret < 0)
return ret;
}
return 0;
}
static int stm32_pwm_probe_breakinputs(struct stm32_pwm *priv,
struct device_node *np)
{
int nb, ret, array_size;
unsigned int i;
nb = of_property_count_elems_of_size(np, "st,breakinput",
sizeof(struct stm32_breakinput));
/*
* Because "st,breakinput" parameter is optional do not make probe
* failed if it doesn't exist.
*/
if (nb <= 0)
return 0;
if (nb > MAX_BREAKINPUT)
return -EINVAL;
priv->num_breakinputs = nb;
array_size = nb * sizeof(struct stm32_breakinput) / sizeof(u32);
ret = of_property_read_u32_array(np, "st,breakinput",
(u32 *)priv->breakinputs, array_size);
if (ret)
return ret;
for (i = 0; i < priv->num_breakinputs; i++) {
if (priv->breakinputs[i].index > 1 ||
priv->breakinputs[i].level > 1 ||
priv->breakinputs[i].filter > 15)
return -EINVAL;
}
return stm32_pwm_apply_breakinputs(priv);
}
static void stm32_pwm_detect_complementary(struct stm32_pwm *priv)
{
u32 ccer;
/*
* If complementary bit doesn't exist writing 1 will have no
* effect so we can detect it.
*/
regmap_set_bits(priv->regmap, TIM_CCER, TIM_CCER_CC1NE);
regmap_read(priv->regmap, TIM_CCER, &ccer);
regmap_clear_bits(priv->regmap, TIM_CCER, TIM_CCER_CC1NE);
priv->have_complementary_output = (ccer != 0);
}
static int stm32_pwm_detect_channels(struct stm32_pwm *priv)
{
u32 ccer;
int npwm = 0;
/*
* If channels enable bits don't exist writing 1 will have no
* effect so we can detect and count them.
*/
regmap_set_bits(priv->regmap, TIM_CCER, TIM_CCER_CCXE);
regmap_read(priv->regmap, TIM_CCER, &ccer);
regmap_clear_bits(priv->regmap, TIM_CCER, TIM_CCER_CCXE);
if (ccer & TIM_CCER_CC1E)
npwm++;
if (ccer & TIM_CCER_CC2E)
npwm++;
if (ccer & TIM_CCER_CC3E)
npwm++;
if (ccer & TIM_CCER_CC4E)
npwm++;
return npwm;
}
static int stm32_pwm_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent);
struct stm32_pwm *priv;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
mutex_init(&priv->lock);
priv->regmap = ddata->regmap;
priv->clk = ddata->clk;
priv->max_arr = ddata->max_arr;
if (!priv->regmap || !priv->clk)
return -EINVAL;
ret = stm32_pwm_probe_breakinputs(priv, np);
if (ret)
return ret;
stm32_pwm_detect_complementary(priv);
priv->chip.dev = dev;
priv->chip.ops = &stm32pwm_ops;
priv->chip.npwm = stm32_pwm_detect_channels(priv);
ret = pwmchip_add(&priv->chip);
if (ret < 0)
return ret;
platform_set_drvdata(pdev, priv);
return 0;
}
static void stm32_pwm_remove(struct platform_device *pdev)
{
struct stm32_pwm *priv = platform_get_drvdata(pdev);
unsigned int i;
for (i = 0; i < priv->chip.npwm; i++)
pwm_disable(&priv->chip.pwms[i]);
pwmchip_remove(&priv->chip);
}
static int __maybe_unused stm32_pwm_suspend(struct device *dev)
{
struct stm32_pwm *priv = dev_get_drvdata(dev);
unsigned int i;
u32 ccer, mask;
/* Look for active channels */
ccer = active_channels(priv);
for (i = 0; i < priv->chip.npwm; i++) {
mask = TIM_CCER_CC1E << (i * 4);
if (ccer & mask) {
dev_err(dev, "PWM %u still in use by consumer %s\n",
i, priv->chip.pwms[i].label);
return -EBUSY;
}
}
return pinctrl_pm_select_sleep_state(dev);
}
static int __maybe_unused stm32_pwm_resume(struct device *dev)
{
struct stm32_pwm *priv = dev_get_drvdata(dev);
int ret;
ret = pinctrl_pm_select_default_state(dev);
if (ret)
return ret;
/* restore breakinput registers that may have been lost in low power */
return stm32_pwm_apply_breakinputs(priv);
}
static SIMPLE_DEV_PM_OPS(stm32_pwm_pm_ops, stm32_pwm_suspend, stm32_pwm_resume);
static const struct of_device_id stm32_pwm_of_match[] = {
{ .compatible = "st,stm32-pwm", },
{ /* end node */ },
};
MODULE_DEVICE_TABLE(of, stm32_pwm_of_match);
static struct platform_driver stm32_pwm_driver = {
.probe = stm32_pwm_probe,
.remove_new = stm32_pwm_remove,
.driver = {
.name = "stm32-pwm",
.of_match_table = stm32_pwm_of_match,
.pm = &stm32_pwm_pm_ops,
},
};
module_platform_driver(stm32_pwm_driver);
MODULE_ALIAS("platform:stm32-pwm");
MODULE_DESCRIPTION("STMicroelectronics STM32 PWM driver");
MODULE_LICENSE("GPL v2");
|