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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Generic pwmlib implementation
4 *
5 * Copyright (C) 2011 Sascha Hauer <[email protected]>
6 * Copyright (C) 2011-2012 Avionic Design GmbH
7 */
8
9#define DEFAULT_SYMBOL_NAMESPACE "PWM"
10
11#include <linux/acpi.h>
12#include <linux/module.h>
13#include <linux/idr.h>
14#include <linux/of.h>
15#include <linux/pwm.h>
16#include <linux/list.h>
17#include <linux/mutex.h>
18#include <linux/err.h>
19#include <linux/slab.h>
20#include <linux/device.h>
21#include <linux/debugfs.h>
22#include <linux/seq_file.h>
23
24#include <dt-bindings/pwm/pwm.h>
25
26#include <uapi/linux/pwm.h>
27
28#define CREATE_TRACE_POINTS
29#include <trace/events/pwm.h>
30
31#define PWM_MINOR_COUNT 256
32
33/* protects access to pwm_chips */
34static DEFINE_MUTEX(pwm_lock);
35
36static DEFINE_IDR(pwm_chips);
37
38static void pwmchip_lock(struct pwm_chip *chip)
39{
40 if (chip->atomic)
41 spin_lock(&chip->atomic_lock);
42 else
43 mutex_lock(&chip->nonatomic_lock);
44}
45
46static void pwmchip_unlock(struct pwm_chip *chip)
47{
48 if (chip->atomic)
49 spin_unlock(&chip->atomic_lock);
50 else
51 mutex_unlock(&chip->nonatomic_lock);
52}
53
54DEFINE_GUARD(pwmchip, struct pwm_chip *, pwmchip_lock(_T), pwmchip_unlock(_T))
55
56static bool pwm_wf_valid(const struct pwm_waveform *wf)
57{
58 /*
59 * For now restrict waveforms to period_length_ns <= S64_MAX to provide
60 * some space for future extensions. One possibility is to simplify
61 * representing waveforms with inverted polarity using negative values
62 * somehow.
63 */
64 if (wf->period_length_ns > S64_MAX)
65 return false;
66
67 if (wf->duty_length_ns > wf->period_length_ns)
68 return false;
69
70 /*
71 * .duty_offset_ns is supposed to be smaller than .period_length_ns, apart
72 * from the corner case .duty_offset_ns == 0 && .period_length_ns == 0.
73 */
74 if (wf->duty_offset_ns && wf->duty_offset_ns >= wf->period_length_ns)
75 return false;
76
77 return true;
78}
79
80static void pwm_wf2state(const struct pwm_waveform *wf, struct pwm_state *state)
81{
82 if (wf->period_length_ns) {
83 if (wf->duty_length_ns + wf->duty_offset_ns < wf->period_length_ns)
84 *state = (struct pwm_state){
85 .enabled = true,
86 .polarity = PWM_POLARITY_NORMAL,
87 .period = wf->period_length_ns,
88 .duty_cycle = wf->duty_length_ns,
89 };
90 else
91 *state = (struct pwm_state){
92 .enabled = true,
93 .polarity = PWM_POLARITY_INVERSED,
94 .period = wf->period_length_ns,
95 .duty_cycle = wf->period_length_ns - wf->duty_length_ns,
96 };
97 } else {
98 *state = (struct pwm_state){
99 .enabled = false,
100 };
101 }
102}
103
104static void pwm_state2wf(const struct pwm_state *state, struct pwm_waveform *wf)
105{
106 if (state->enabled) {
107 if (state->polarity == PWM_POLARITY_NORMAL)
108 *wf = (struct pwm_waveform){
109 .period_length_ns = state->period,
110 .duty_length_ns = state->duty_cycle,
111 .duty_offset_ns = 0,
112 };
113 else
114 *wf = (struct pwm_waveform){
115 .period_length_ns = state->period,
116 .duty_length_ns = state->period - state->duty_cycle,
117 .duty_offset_ns = state->duty_cycle,
118 };
119 } else {
120 *wf = (struct pwm_waveform){
121 .period_length_ns = 0,
122 };
123 }
124}
125
126static int pwmwfcmp(const struct pwm_waveform *a, const struct pwm_waveform *b)
127{
128 if (a->period_length_ns > b->period_length_ns)
129 return 1;
130
131 if (a->period_length_ns < b->period_length_ns)
132 return -1;
133
134 if (a->duty_length_ns > b->duty_length_ns)
135 return 1;
136
137 if (a->duty_length_ns < b->duty_length_ns)
138 return -1;
139
140 if (a->duty_offset_ns > b->duty_offset_ns)
141 return 1;
142
143 if (a->duty_offset_ns < b->duty_offset_ns)
144 return -1;
145
146 return 0;
147}
148
149static bool pwm_check_rounding(const struct pwm_waveform *wf,
150 const struct pwm_waveform *wf_rounded)
151{
152 if (!wf->period_length_ns)
153 return true;
154
155 if (wf->period_length_ns < wf_rounded->period_length_ns)
156 return false;
157
158 if (wf->duty_length_ns < wf_rounded->duty_length_ns)
159 return false;
160
161 if (wf->duty_offset_ns < wf_rounded->duty_offset_ns)
162 return false;
163
164 return true;
165}
166
167static int __pwm_round_waveform_tohw(struct pwm_chip *chip, struct pwm_device *pwm,
168 const struct pwm_waveform *wf, void *wfhw)
169{
170 const struct pwm_ops *ops = chip->ops;
171 int ret;
172
173 ret = ops->round_waveform_tohw(chip, pwm, wf, wfhw);
174 trace_pwm_round_waveform_tohw(pwm, wf, wfhw, ret);
175
176 return ret;
177}
178
179static int __pwm_round_waveform_fromhw(struct pwm_chip *chip, struct pwm_device *pwm,
180 const void *wfhw, struct pwm_waveform *wf)
181{
182 const struct pwm_ops *ops = chip->ops;
183 int ret;
184
185 ret = ops->round_waveform_fromhw(chip, pwm, wfhw, wf);
186 trace_pwm_round_waveform_fromhw(pwm, wfhw, wf, ret);
187
188 return ret;
189}
190
191static int __pwm_read_waveform(struct pwm_chip *chip, struct pwm_device *pwm, void *wfhw)
192{
193 const struct pwm_ops *ops = chip->ops;
194 int ret;
195
196 ret = ops->read_waveform(chip, pwm, wfhw);
197 trace_pwm_read_waveform(pwm, wfhw, ret);
198
199 return ret;
200}
201
202static int __pwm_write_waveform(struct pwm_chip *chip, struct pwm_device *pwm, const void *wfhw)
203{
204 const struct pwm_ops *ops = chip->ops;
205 int ret;
206
207 ret = ops->write_waveform(chip, pwm, wfhw);
208 trace_pwm_write_waveform(pwm, wfhw, ret);
209
210 return ret;
211}
212
213/**
214 * pwm_round_waveform_might_sleep - Query hardware capabilities
215 * Cannot be used in atomic context.
216 * @pwm: PWM device
217 * @wf: waveform to round and output parameter
218 *
219 * Typically a given waveform cannot be implemented exactly by hardware, e.g.
220 * because hardware only supports coarse period resolution or no duty_offset.
221 * This function returns the actually implemented waveform if you pass @wf to
222 * pwm_set_waveform_might_sleep() now.
223 *
224 * Note however that the world doesn't stop turning when you call it, so when
225 * doing::
226 *
227 * pwm_round_waveform_might_sleep(mypwm, &wf);
228 * pwm_set_waveform_might_sleep(mypwm, &wf, true);
229 *
230 * the latter might fail, e.g. because an input clock changed its rate between
231 * these two calls and the waveform determined by
232 * pwm_round_waveform_might_sleep() cannot be implemented any more.
233 *
234 * Usually all values passed in @wf are rounded down to the nearest possible
235 * value (in the order period_length_ns, duty_length_ns and then
236 * duty_offset_ns). Only if this isn't possible, a value might grow. See the
237 * documentation for pwm_set_waveform_might_sleep() for a more formal
238 * description.
239 *
240 * Returns: 0 on success, 1 if at least one value had to be rounded up or a
241 * negative errno.
242 * Context: May sleep.
243 */
244int pwm_round_waveform_might_sleep(struct pwm_device *pwm, struct pwm_waveform *wf)
245{
246 struct pwm_chip *chip = pwm->chip;
247 const struct pwm_ops *ops = chip->ops;
248 struct pwm_waveform wf_req = *wf;
249 char wfhw[PWM_WFHWSIZE];
250 int ret_tohw, ret_fromhw;
251
252 BUG_ON(PWM_WFHWSIZE < ops->sizeof_wfhw);
253
254 if (!pwmchip_supports_waveform(chip))
255 return -EOPNOTSUPP;
256
257 if (!pwm_wf_valid(wf))
258 return -EINVAL;
259
260 guard(pwmchip)(chip);
261
262 if (!chip->operational)
263 return -ENODEV;
264
265 ret_tohw = __pwm_round_waveform_tohw(chip, pwm, wf, wfhw);
266 if (ret_tohw < 0)
267 return ret_tohw;
268
269 if (IS_ENABLED(CONFIG_PWM_DEBUG) && ret_tohw > 1)
270 dev_err(&chip->dev, "Unexpected return value from __pwm_round_waveform_tohw: requested %llu/%llu [+%llu], return value %d\n",
271 wf_req.duty_length_ns, wf_req.period_length_ns, wf_req.duty_offset_ns, ret_tohw);
272
273 ret_fromhw = __pwm_round_waveform_fromhw(chip, pwm, wfhw, wf);
274 if (ret_fromhw < 0)
275 return ret_fromhw;
276
277 if (IS_ENABLED(CONFIG_PWM_DEBUG) && ret_fromhw > 0)
278 dev_err(&chip->dev, "Unexpected return value from __pwm_round_waveform_fromhw: requested %llu/%llu [+%llu], return value %d\n",
279 wf_req.duty_length_ns, wf_req.period_length_ns, wf_req.duty_offset_ns, ret_fromhw);
280
281 if (IS_ENABLED(CONFIG_PWM_DEBUG) &&
282 (ret_tohw == 0) != pwm_check_rounding(&wf_req, wf))
283 dev_err(&chip->dev, "Wrong rounding: requested %llu/%llu [+%llu], result %llu/%llu [+%llu], ret: %d\n",
284 wf_req.duty_length_ns, wf_req.period_length_ns, wf_req.duty_offset_ns,
285 wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns, ret_tohw);
286
287 return ret_tohw;
288}
289EXPORT_SYMBOL_GPL(pwm_round_waveform_might_sleep);
290
291/**
292 * pwm_get_waveform_might_sleep - Query hardware about current configuration
293 * Cannot be used in atomic context.
294 * @pwm: PWM device
295 * @wf: output parameter
296 *
297 * Stores the current configuration of the PWM in @wf. Note this is the
298 * equivalent of pwm_get_state_hw() (and not pwm_get_state()) for pwm_waveform.
299 *
300 * Returns: 0 on success or a negative errno
301 * Context: May sleep.
302 */
303int pwm_get_waveform_might_sleep(struct pwm_device *pwm, struct pwm_waveform *wf)
304{
305 struct pwm_chip *chip = pwm->chip;
306 const struct pwm_ops *ops = chip->ops;
307 char wfhw[PWM_WFHWSIZE];
308 int err;
309
310 BUG_ON(PWM_WFHWSIZE < ops->sizeof_wfhw);
311
312 if (!pwmchip_supports_waveform(chip) || !ops->read_waveform)
313 return -EOPNOTSUPP;
314
315 guard(pwmchip)(chip);
316
317 if (!chip->operational)
318 return -ENODEV;
319
320 err = __pwm_read_waveform(chip, pwm, &wfhw);
321 if (err)
322 return err;
323
324 return __pwm_round_waveform_fromhw(chip, pwm, &wfhw, wf);
325}
326EXPORT_SYMBOL_GPL(pwm_get_waveform_might_sleep);
327
328/* Called with the pwmchip lock held */
329static int __pwm_set_waveform(struct pwm_device *pwm,
330 const struct pwm_waveform *wf,
331 bool exact)
332{
333 struct pwm_chip *chip = pwm->chip;
334 const struct pwm_ops *ops = chip->ops;
335 char wfhw[PWM_WFHWSIZE];
336 struct pwm_waveform wf_rounded;
337 int err, ret_tohw;
338
339 BUG_ON(PWM_WFHWSIZE < ops->sizeof_wfhw);
340
341 if (!pwmchip_supports_waveform(chip))
342 return -EOPNOTSUPP;
343
344 if (!pwm_wf_valid(wf))
345 return -EINVAL;
346
347 ret_tohw = __pwm_round_waveform_tohw(chip, pwm, wf, &wfhw);
348 if (ret_tohw < 0)
349 return ret_tohw;
350
351 if ((IS_ENABLED(CONFIG_PWM_DEBUG) || exact) && wf->period_length_ns) {
352 err = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf_rounded);
353 if (err)
354 return err;
355
356 if (IS_ENABLED(CONFIG_PWM_DEBUG) && (ret_tohw == 0) != pwm_check_rounding(wf, &wf_rounded))
357 dev_err(&chip->dev, "Wrong rounding: requested %llu/%llu [+%llu], result %llu/%llu [+%llu], ret: %d\n",
358 wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns,
359 wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns, ret_tohw);
360
361 if (exact && pwmwfcmp(wf, &wf_rounded)) {
362 dev_dbg(&chip->dev, "Requested no rounding, but %llu/%llu [+%llu] -> %llu/%llu [+%llu]\n",
363 wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns,
364 wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns);
365
366 return 1;
367 }
368 }
369
370 err = __pwm_write_waveform(chip, pwm, &wfhw);
371 if (err)
372 return err;
373
374 /* update .state */
375 pwm_wf2state(wf, &pwm->state);
376
377 if (IS_ENABLED(CONFIG_PWM_DEBUG) && ops->read_waveform && wf->period_length_ns) {
378 struct pwm_waveform wf_set;
379
380 err = __pwm_read_waveform(chip, pwm, &wfhw);
381 if (err)
382 /* maybe ignore? */
383 return err;
384
385 err = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf_set);
386 if (err)
387 /* maybe ignore? */
388 return err;
389
390 if (pwmwfcmp(&wf_set, &wf_rounded) != 0)
391 dev_err(&chip->dev,
392 "Unexpected setting: requested %llu/%llu [+%llu], expected %llu/%llu [+%llu], set %llu/%llu [+%llu]\n",
393 wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns,
394 wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns,
395 wf_set.duty_length_ns, wf_set.period_length_ns, wf_set.duty_offset_ns);
396 }
397
398 return ret_tohw;
399}
400
401/**
402 * pwm_set_waveform_might_sleep - Apply a new waveform
403 * Cannot be used in atomic context.
404 * @pwm: PWM device
405 * @wf: The waveform to apply
406 * @exact: If true no rounding is allowed
407 *
408 * Typically a requested waveform cannot be implemented exactly, e.g. because
409 * you requested .period_length_ns = 100 ns, but the hardware can only set
410 * periods that are a multiple of 8.5 ns. With that hardware passing @exact =
411 * true results in pwm_set_waveform_might_sleep() failing and returning -EDOM.
412 * If @exact = false you get a period of 93.5 ns (i.e. the biggest period not
413 * bigger than the requested value).
414 * Note that even with @exact = true, some rounding by less than 1 ns is
415 * possible/needed. In the above example requesting .period_length_ns = 94 and
416 * @exact = true, you get the hardware configured with period = 93.5 ns.
417 *
418 * Let C be the set of possible hardware configurations for a given PWM device,
419 * consisting of tuples (p, d, o) where p is the period length, d is the duty
420 * length and o the duty offset.
421 *
422 * The following algorithm is implemented to pick the hardware setting
423 * (p, d, o) ∈ C for a given request (p', d', o') with @exact = false::
424 *
425 * p = max( { ṗ | ∃ ḋ, ȯ : (ṗ, ḋ, ȯ) ∈ C ∧ ṗ ≤ p' } ∪ { min({ ṗ | ∃ ḋ, ȯ : (ṗ, ḋ, ȯ) ∈ C }) })
426 * d = max( { ḋ | ∃ ȯ : (p, ḋ, ȯ) ∈ C ∧ ḋ ≤ d' } ∪ { min({ ḋ | ∃ ȯ : (p, ḋ, ȯ) ∈ C }) })
427 * o = max( { ȯ | (p, d, ȯ) ∈ C ∧ ȯ ≤ o' } ∪ { min({ ȯ | (p, d, ȯ) ∈ C }) })
428 *
429 * In words: The chosen period length is the maximal possible period length not
430 * bigger than the requested period length and if that doesn't exist, the
431 * minimal period length. The chosen duty length is the maximal possible duty
432 * length that is compatible with the chosen period length and isn't bigger than
433 * the requested duty length. Again if such a value doesn't exist, the minimal
434 * duty length compatible with the chosen period is picked. After that the duty
435 * offset compatible with the chosen period and duty length is chosen in the
436 * same way.
437 *
438 * Returns: 0 on success, -EDOM if setting failed due to the exact waveform not
439 * being possible (if @exact), or a different negative errno on failure.
440 * Context: May sleep.
441 */
442int pwm_set_waveform_might_sleep(struct pwm_device *pwm,
443 const struct pwm_waveform *wf, bool exact)
444{
445 struct pwm_chip *chip = pwm->chip;
446 int err;
447
448 might_sleep();
449
450 guard(pwmchip)(chip);
451
452 if (!chip->operational)
453 return -ENODEV;
454
455 if (IS_ENABLED(CONFIG_PWM_DEBUG) && chip->atomic) {
456 /*
457 * Catch any drivers that have been marked as atomic but
458 * that will sleep anyway.
459 */
460 non_block_start();
461 err = __pwm_set_waveform(pwm, wf, exact);
462 non_block_end();
463 } else {
464 err = __pwm_set_waveform(pwm, wf, exact);
465 }
466
467 /*
468 * map err == 1 to -EDOM for exact requests and 0 for !exact ones. Also
469 * make sure that -EDOM is only returned in exactly that case. Note that
470 * __pwm_set_waveform() should never return -EDOM which justifies the
471 * unlikely().
472 */
473 if (unlikely(err == -EDOM))
474 err = -EINVAL;
475 else if (exact && err == 1)
476 err = -EDOM;
477 else if (err == 1)
478 err = 0;
479
480 return err;
481}
482EXPORT_SYMBOL_GPL(pwm_set_waveform_might_sleep);
483
484static void pwm_apply_debug(struct pwm_device *pwm,
485 const struct pwm_state *state)
486{
487 struct pwm_state *last = &pwm->last;
488 struct pwm_chip *chip = pwm->chip;
489 struct pwm_state s1 = { 0 }, s2 = { 0 };
490 int err;
491
492 if (!IS_ENABLED(CONFIG_PWM_DEBUG))
493 return;
494
495 /* No reasonable diagnosis possible without .get_state() */
496 if (!chip->ops->get_state)
497 return;
498
499 /*
500 * If a disabled PWM was requested the result is unspecified, so nothing
501 * to check.
502 */
503 if (!state->enabled)
504 return;
505
506 /*
507 * *state was just applied. Read out the hardware state and do some
508 * checks.
509 */
510
511 err = chip->ops->get_state(chip, pwm, &s1);
512 trace_pwm_get(pwm, &s1, err);
513 if (err)
514 /* If that failed there isn't much to debug */
515 return;
516
517 /*
518 * If the PWM was disabled that's maybe strange but there is nothing
519 * that can be sensibly checked then. So return early.
520 */
521 if (!s1.enabled)
522 return;
523
524 /*
525 * The lowlevel driver either ignored .polarity (which is a bug) or as
526 * best effort inverted .polarity and fixed .duty_cycle respectively.
527 * Undo this inversion and fixup for further tests.
528 */
529 if (s1.polarity != state->polarity) {
530 s2.polarity = state->polarity;
531 s2.duty_cycle = s1.period - s1.duty_cycle;
532 s2.period = s1.period;
533 s2.enabled = true;
534 } else {
535 s2 = s1;
536 }
537
538 if (s2.polarity != state->polarity &&
539 s2.duty_cycle < s2.period)
540 dev_warn(pwmchip_parent(chip), ".apply ignored .polarity\n");
541
542 if (last->polarity == state->polarity &&
543 last->period > s2.period &&
544 last->period <= state->period)
545 dev_warn(pwmchip_parent(chip),
546 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
547 state->period, s2.period, last->period);
548
549 /*
550 * Rounding period up is fine only if duty_cycle is 0 then, because a
551 * flat line doesn't have a characteristic period.
552 */
553 if (state->period < s2.period && s2.duty_cycle)
554 dev_warn(pwmchip_parent(chip),
555 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
556 state->period, s2.period);
557
558 if (last->polarity == state->polarity &&
559 last->period == s2.period &&
560 last->duty_cycle > s2.duty_cycle &&
561 last->duty_cycle <= state->duty_cycle)
562 dev_warn(pwmchip_parent(chip),
563 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
564 state->duty_cycle, state->period,
565 s2.duty_cycle, s2.period,
566 last->duty_cycle, last->period);
567
568 if (state->duty_cycle < s2.duty_cycle)
569 dev_warn(pwmchip_parent(chip),
570 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
571 state->duty_cycle, state->period,
572 s2.duty_cycle, s2.period);
573
574 /* reapply the state that the driver reported being configured. */
575 err = chip->ops->apply(chip, pwm, &s1);
576 trace_pwm_apply(pwm, &s1, err);
577 if (err) {
578 *last = s1;
579 dev_err(pwmchip_parent(chip), "failed to reapply current setting\n");
580 return;
581 }
582
583 *last = (struct pwm_state){ 0 };
584 err = chip->ops->get_state(chip, pwm, last);
585 trace_pwm_get(pwm, last, err);
586 if (err)
587 return;
588
589 /* reapplication of the current state should give an exact match */
590 if (s1.enabled != last->enabled ||
591 s1.polarity != last->polarity ||
592 (s1.enabled && s1.period != last->period) ||
593 (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
594 dev_err(pwmchip_parent(chip),
595 ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
596 s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
597 last->enabled, last->polarity, last->duty_cycle,
598 last->period);
599 }
600}
601
602static bool pwm_state_valid(const struct pwm_state *state)
603{
604 /*
605 * For a disabled state all other state description is irrelevant and
606 * and supposed to be ignored. So also ignore any strange values and
607 * consider the state ok.
608 */
609 if (!state->enabled)
610 return true;
611
612 if (!state->period)
613 return false;
614
615 if (state->duty_cycle > state->period)
616 return false;
617
618 return true;
619}
620
621static int __pwm_apply(struct pwm_device *pwm, const struct pwm_state *state)
622{
623 struct pwm_chip *chip;
624 const struct pwm_ops *ops;
625 int err;
626
627 if (!pwm || !state)
628 return -EINVAL;
629
630 if (!pwm_state_valid(state)) {
631 /*
632 * Allow to transition from one invalid state to another.
633 * This ensures that you can e.g. change the polarity while
634 * the period is zero. (This happens on stm32 when the hardware
635 * is in its poweron default state.) This greatly simplifies
636 * working with the sysfs API where you can only change one
637 * parameter at a time.
638 */
639 if (!pwm_state_valid(&pwm->state)) {
640 pwm->state = *state;
641 return 0;
642 }
643
644 return -EINVAL;
645 }
646
647 chip = pwm->chip;
648 ops = chip->ops;
649
650 if (state->period == pwm->state.period &&
651 state->duty_cycle == pwm->state.duty_cycle &&
652 state->polarity == pwm->state.polarity &&
653 state->enabled == pwm->state.enabled &&
654 state->usage_power == pwm->state.usage_power)
655 return 0;
656
657 if (pwmchip_supports_waveform(chip)) {
658 struct pwm_waveform wf;
659 char wfhw[PWM_WFHWSIZE];
660
661 BUG_ON(PWM_WFHWSIZE < ops->sizeof_wfhw);
662
663 pwm_state2wf(state, &wf);
664
665 /*
666 * The rounding is wrong here for states with inverted polarity.
667 * While .apply() rounds down duty_cycle (which represents the
668 * time from the start of the period to the inner edge),
669 * .round_waveform_tohw() rounds down the time the PWM is high.
670 * Can be fixed if the need arises, until reported otherwise
671 * let's assume that consumers don't care.
672 */
673
674 err = __pwm_round_waveform_tohw(chip, pwm, &wf, &wfhw);
675 if (err) {
676 if (err > 0)
677 /*
678 * This signals an invalid request, typically
679 * the requested period (or duty_offset) is
680 * smaller than possible with the hardware.
681 */
682 return -EINVAL;
683
684 return err;
685 }
686
687 if (IS_ENABLED(CONFIG_PWM_DEBUG)) {
688 struct pwm_waveform wf_rounded;
689
690 err = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf_rounded);
691 if (err)
692 return err;
693
694 if (!pwm_check_rounding(&wf, &wf_rounded))
695 dev_err(&chip->dev, "Wrong rounding: requested %llu/%llu [+%llu], result %llu/%llu [+%llu]\n",
696 wf.duty_length_ns, wf.period_length_ns, wf.duty_offset_ns,
697 wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns);
698 }
699
700 err = __pwm_write_waveform(chip, pwm, &wfhw);
701 if (err)
702 return err;
703
704 pwm->state = *state;
705
706 } else {
707 err = ops->apply(chip, pwm, state);
708 trace_pwm_apply(pwm, state, err);
709 if (err)
710 return err;
711
712 pwm->state = *state;
713
714 /*
715 * only do this after pwm->state was applied as some
716 * implementations of .get_state() depend on this
717 */
718 pwm_apply_debug(pwm, state);
719 }
720
721 return 0;
722}
723
724/**
725 * pwm_apply_might_sleep() - atomically apply a new state to a PWM device
726 * Cannot be used in atomic context.
727 * @pwm: PWM device
728 * @state: new state to apply
729 *
730 * Returns: 0 on success, or a negative errno
731 * Context: May sleep.
732 */
733int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state)
734{
735 int err;
736 struct pwm_chip *chip = pwm->chip;
737
738 /*
739 * Some lowlevel driver's implementations of .apply() make use of
740 * mutexes, also with some drivers only returning when the new
741 * configuration is active calling pwm_apply_might_sleep() from atomic context
742 * is a bad idea. So make it explicit that calling this function might
743 * sleep.
744 */
745 might_sleep();
746
747 guard(pwmchip)(chip);
748
749 if (!chip->operational)
750 return -ENODEV;
751
752 if (IS_ENABLED(CONFIG_PWM_DEBUG) && chip->atomic) {
753 /*
754 * Catch any drivers that have been marked as atomic but
755 * that will sleep anyway.
756 */
757 non_block_start();
758 err = __pwm_apply(pwm, state);
759 non_block_end();
760 } else {
761 err = __pwm_apply(pwm, state);
762 }
763
764 return err;
765}
766EXPORT_SYMBOL_GPL(pwm_apply_might_sleep);
767
768/**
769 * pwm_apply_atomic() - apply a new state to a PWM device from atomic context
770 * Not all PWM devices support this function, check with pwm_might_sleep().
771 * @pwm: PWM device
772 * @state: new state to apply
773 *
774 * Returns: 0 on success, or a negative errno
775 * Context: Any
776 */
777int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state)
778{
779 struct pwm_chip *chip = pwm->chip;
780
781 WARN_ONCE(!chip->atomic,
782 "sleeping PWM driver used in atomic context\n");
783
784 guard(pwmchip)(chip);
785
786 if (!chip->operational)
787 return -ENODEV;
788
789 return __pwm_apply(pwm, state);
790}
791EXPORT_SYMBOL_GPL(pwm_apply_atomic);
792
793/**
794 * pwm_get_state_hw() - get the current PWM state from hardware
795 * @pwm: PWM device
796 * @state: state to fill with the current PWM state
797 *
798 * Similar to pwm_get_state() but reads the current PWM state from hardware
799 * instead of the requested state.
800 *
801 * Returns: 0 on success or a negative error code on failure.
802 * Context: May sleep.
803 */
804int pwm_get_state_hw(struct pwm_device *pwm, struct pwm_state *state)
805{
806 struct pwm_chip *chip = pwm->chip;
807 const struct pwm_ops *ops = chip->ops;
808 int ret = -EOPNOTSUPP;
809
810 might_sleep();
811
812 guard(pwmchip)(chip);
813
814 if (!chip->operational)
815 return -ENODEV;
816
817 if (pwmchip_supports_waveform(chip) && ops->read_waveform) {
818 char wfhw[PWM_WFHWSIZE];
819 struct pwm_waveform wf;
820
821 BUG_ON(PWM_WFHWSIZE < ops->sizeof_wfhw);
822
823 ret = __pwm_read_waveform(chip, pwm, &wfhw);
824 if (ret)
825 return ret;
826
827 ret = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf);
828 if (ret)
829 return ret;
830
831 pwm_wf2state(&wf, state);
832
833 } else if (ops->get_state) {
834 ret = ops->get_state(chip, pwm, state);
835 trace_pwm_get(pwm, state, ret);
836 }
837
838 return ret;
839}
840EXPORT_SYMBOL_GPL(pwm_get_state_hw);
841
842/**
843 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
844 * @pwm: PWM device
845 *
846 * This function will adjust the PWM config to the PWM arguments provided
847 * by the DT or PWM lookup table. This is particularly useful to adapt
848 * the bootloader config to the Linux one.
849 *
850 * Returns: 0 on success or a negative error code on failure.
851 * Context: May sleep.
852 */
853int pwm_adjust_config(struct pwm_device *pwm)
854{
855 struct pwm_state state;
856 struct pwm_args pargs;
857
858 pwm_get_args(pwm, &pargs);
859 pwm_get_state(pwm, &state);
860
861 /*
862 * If the current period is zero it means that either the PWM driver
863 * does not support initial state retrieval or the PWM has not yet
864 * been configured.
865 *
866 * In either case, we setup the new period and polarity, and assign a
867 * duty cycle of 0.
868 */
869 if (!state.period) {
870 state.duty_cycle = 0;
871 state.period = pargs.period;
872 state.polarity = pargs.polarity;
873
874 return pwm_apply_might_sleep(pwm, &state);
875 }
876
877 /*
878 * Adjust the PWM duty cycle/period based on the period value provided
879 * in PWM args.
880 */
881 if (pargs.period != state.period) {
882 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
883
884 do_div(dutycycle, state.period);
885 state.duty_cycle = dutycycle;
886 state.period = pargs.period;
887 }
888
889 /*
890 * If the polarity changed, we should also change the duty cycle.
891 */
892 if (pargs.polarity != state.polarity) {
893 state.polarity = pargs.polarity;
894 state.duty_cycle = state.period - state.duty_cycle;
895 }
896
897 return pwm_apply_might_sleep(pwm, &state);
898}
899EXPORT_SYMBOL_GPL(pwm_adjust_config);
900
901/**
902 * pwm_capture() - capture and report a PWM signal
903 * @pwm: PWM device
904 * @result: structure to fill with capture result
905 * @timeout: time to wait, in milliseconds, before giving up on capture
906 *
907 * Returns: 0 on success or a negative error code on failure.
908 */
909static int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
910 unsigned long timeout)
911{
912 struct pwm_chip *chip = pwm->chip;
913 const struct pwm_ops *ops = chip->ops;
914
915 if (!ops->capture)
916 return -ENOSYS;
917
918 /*
919 * Holding the pwm_lock is probably not needed. If you use pwm_capture()
920 * and you're interested to speed it up, please convince yourself it's
921 * really not needed, test and then suggest a patch on the mailing list.
922 */
923 guard(mutex)(&pwm_lock);
924
925 guard(pwmchip)(chip);
926
927 if (!chip->operational)
928 return -ENODEV;
929
930 return ops->capture(chip, pwm, result, timeout);
931}
932
933static struct pwm_chip *pwmchip_find_by_name(const char *name)
934{
935 struct pwm_chip *chip;
936 unsigned long id, tmp;
937
938 if (!name)
939 return NULL;
940
941 guard(mutex)(&pwm_lock);
942
943 idr_for_each_entry_ul(&pwm_chips, chip, tmp, id) {
944 if (device_match_name(pwmchip_parent(chip), name))
945 return chip;
946 }
947
948 return NULL;
949}
950
951static int pwm_device_request(struct pwm_device *pwm, const char *label)
952{
953 int err;
954 struct pwm_chip *chip = pwm->chip;
955 const struct pwm_ops *ops = chip->ops;
956
957 if (test_bit(PWMF_REQUESTED, &pwm->flags))
958 return -EBUSY;
959
960 /*
961 * This function is called while holding pwm_lock. As .operational only
962 * changes while holding this lock, checking it here without holding the
963 * chip lock is fine.
964 */
965 if (!chip->operational)
966 return -ENODEV;
967
968 if (!try_module_get(chip->owner))
969 return -ENODEV;
970
971 if (!get_device(&chip->dev)) {
972 err = -ENODEV;
973 goto err_get_device;
974 }
975
976 if (ops->request) {
977 err = ops->request(chip, pwm);
978 if (err) {
979 put_device(&chip->dev);
980err_get_device:
981 module_put(chip->owner);
982 return err;
983 }
984 }
985
986 if (ops->read_waveform || ops->get_state) {
987 /*
988 * Zero-initialize state because most drivers are unaware of
989 * .usage_power. The other members of state are supposed to be
990 * set by lowlevel drivers. We still initialize the whole
991 * structure for simplicity even though this might paper over
992 * faulty implementations of .get_state().
993 */
994 struct pwm_state state = { 0, };
995
996 err = pwm_get_state_hw(pwm, &state);
997 if (!err)
998 pwm->state = state;
999
1000 if (IS_ENABLED(CONFIG_PWM_DEBUG))
1001 pwm->last = pwm->state;
1002 }
1003
1004 set_bit(PWMF_REQUESTED, &pwm->flags);
1005 pwm->label = label;
1006
1007 return 0;
1008}
1009
1010/**
1011 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
1012 * @chip: PWM chip
1013 * @index: per-chip index of the PWM to request
1014 * @label: a literal description string of this PWM
1015 *
1016 * Returns: A pointer to the PWM device at the given index of the given PWM
1017 * chip. A negative error code is returned if the index is not valid for the
1018 * specified PWM chip or if the PWM device cannot be requested.
1019 */
1020static struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
1021 unsigned int index,
1022 const char *label)
1023{
1024 struct pwm_device *pwm;
1025 int err;
1026
1027 if (!chip || index >= chip->npwm)
1028 return ERR_PTR(-EINVAL);
1029
1030 guard(mutex)(&pwm_lock);
1031
1032 pwm = &chip->pwms[index];
1033
1034 err = pwm_device_request(pwm, label);
1035 if (err < 0)
1036 return ERR_PTR(err);
1037
1038 return pwm;
1039}
1040
1041struct pwm_device *
1042of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *args)
1043{
1044 struct pwm_device *pwm;
1045
1046 /* period in the second cell and flags in the third cell are optional */
1047 if (args->args_count < 1)
1048 return ERR_PTR(-EINVAL);
1049
1050 pwm = pwm_request_from_chip(chip, args->args[0], NULL);
1051 if (IS_ERR(pwm))
1052 return pwm;
1053
1054 if (args->args_count > 1)
1055 pwm->args.period = args->args[1];
1056
1057 pwm->args.polarity = PWM_POLARITY_NORMAL;
1058 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
1059 pwm->args.polarity = PWM_POLARITY_INVERSED;
1060
1061 return pwm;
1062}
1063EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
1064
1065/*
1066 * This callback is used for PXA PWM chips that only have a single PWM line.
1067 * For such chips you could argue that passing the line number (i.e. the first
1068 * parameter in the common case) is useless as it's always zero. So compared to
1069 * the default xlate function of_pwm_xlate_with_flags() the first parameter is
1070 * the default period and the second are flags.
1071 *
1072 * Note that if #pwm-cells = <3>, the semantic is the same as for
1073 * of_pwm_xlate_with_flags() to allow converting the affected driver to
1074 * #pwm-cells = <3> without breaking the legacy binding.
1075 *
1076 * Don't use for new drivers.
1077 */
1078struct pwm_device *
1079of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args)
1080{
1081 struct pwm_device *pwm;
1082
1083 if (args->args_count >= 3)
1084 return of_pwm_xlate_with_flags(chip, args);
1085
1086 pwm = pwm_request_from_chip(chip, 0, NULL);
1087 if (IS_ERR(pwm))
1088 return pwm;
1089
1090 if (args->args_count > 0)
1091 pwm->args.period = args->args[0];
1092
1093 pwm->args.polarity = PWM_POLARITY_NORMAL;
1094 if (args->args_count > 1 && args->args[1] & PWM_POLARITY_INVERTED)
1095 pwm->args.polarity = PWM_POLARITY_INVERSED;
1096
1097 return pwm;
1098}
1099EXPORT_SYMBOL_GPL(of_pwm_single_xlate);
1100
1101struct pwm_export {
1102 struct device pwm_dev;
1103 struct pwm_device *pwm;
1104 struct mutex lock;
1105 struct pwm_state suspend;
1106};
1107
1108static inline struct pwm_chip *pwmchip_from_dev(struct device *pwmchip_dev)
1109{
1110 return container_of(pwmchip_dev, struct pwm_chip, dev);
1111}
1112
1113static inline struct pwm_export *pwmexport_from_dev(struct device *pwm_dev)
1114{
1115 return container_of(pwm_dev, struct pwm_export, pwm_dev);
1116}
1117
1118static inline struct pwm_device *pwm_from_dev(struct device *pwm_dev)
1119{
1120 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1121
1122 return export->pwm;
1123}
1124
1125static ssize_t period_show(struct device *pwm_dev,
1126 struct device_attribute *attr,
1127 char *buf)
1128{
1129 const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
1130 struct pwm_state state;
1131
1132 pwm_get_state(pwm, &state);
1133
1134 return sysfs_emit(buf, "%llu\n", state.period);
1135}
1136
1137static ssize_t period_store(struct device *pwm_dev,
1138 struct device_attribute *attr,
1139 const char *buf, size_t size)
1140{
1141 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1142 struct pwm_device *pwm = export->pwm;
1143 struct pwm_state state;
1144 u64 val;
1145 int ret;
1146
1147 ret = kstrtou64(buf, 0, &val);
1148 if (ret)
1149 return ret;
1150
1151 guard(mutex)(&export->lock);
1152
1153 pwm_get_state(pwm, &state);
1154 state.period = val;
1155 ret = pwm_apply_might_sleep(pwm, &state);
1156
1157 return ret ? : size;
1158}
1159
1160static ssize_t duty_cycle_show(struct device *pwm_dev,
1161 struct device_attribute *attr,
1162 char *buf)
1163{
1164 const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
1165 struct pwm_state state;
1166
1167 pwm_get_state(pwm, &state);
1168
1169 return sysfs_emit(buf, "%llu\n", state.duty_cycle);
1170}
1171
1172static ssize_t duty_cycle_store(struct device *pwm_dev,
1173 struct device_attribute *attr,
1174 const char *buf, size_t size)
1175{
1176 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1177 struct pwm_device *pwm = export->pwm;
1178 struct pwm_state state;
1179 u64 val;
1180 int ret;
1181
1182 ret = kstrtou64(buf, 0, &val);
1183 if (ret)
1184 return ret;
1185
1186 guard(mutex)(&export->lock);
1187
1188 pwm_get_state(pwm, &state);
1189 state.duty_cycle = val;
1190 ret = pwm_apply_might_sleep(pwm, &state);
1191
1192 return ret ? : size;
1193}
1194
1195static ssize_t enable_show(struct device *pwm_dev,
1196 struct device_attribute *attr,
1197 char *buf)
1198{
1199 const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
1200 struct pwm_state state;
1201
1202 pwm_get_state(pwm, &state);
1203
1204 return sysfs_emit(buf, "%d\n", state.enabled);
1205}
1206
1207static ssize_t enable_store(struct device *pwm_dev,
1208 struct device_attribute *attr,
1209 const char *buf, size_t size)
1210{
1211 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1212 struct pwm_device *pwm = export->pwm;
1213 struct pwm_state state;
1214 int val, ret;
1215
1216 ret = kstrtoint(buf, 0, &val);
1217 if (ret)
1218 return ret;
1219
1220 guard(mutex)(&export->lock);
1221
1222 pwm_get_state(pwm, &state);
1223
1224 switch (val) {
1225 case 0:
1226 state.enabled = false;
1227 break;
1228 case 1:
1229 state.enabled = true;
1230 break;
1231 default:
1232 return -EINVAL;
1233 }
1234
1235 ret = pwm_apply_might_sleep(pwm, &state);
1236
1237 return ret ? : size;
1238}
1239
1240static ssize_t polarity_show(struct device *pwm_dev,
1241 struct device_attribute *attr,
1242 char *buf)
1243{
1244 const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
1245 const char *polarity = "unknown";
1246 struct pwm_state state;
1247
1248 pwm_get_state(pwm, &state);
1249
1250 switch (state.polarity) {
1251 case PWM_POLARITY_NORMAL:
1252 polarity = "normal";
1253 break;
1254
1255 case PWM_POLARITY_INVERSED:
1256 polarity = "inversed";
1257 break;
1258 }
1259
1260 return sysfs_emit(buf, "%s\n", polarity);
1261}
1262
1263static ssize_t polarity_store(struct device *pwm_dev,
1264 struct device_attribute *attr,
1265 const char *buf, size_t size)
1266{
1267 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1268 struct pwm_device *pwm = export->pwm;
1269 enum pwm_polarity polarity;
1270 struct pwm_state state;
1271 int ret;
1272
1273 if (sysfs_streq(buf, "normal"))
1274 polarity = PWM_POLARITY_NORMAL;
1275 else if (sysfs_streq(buf, "inversed"))
1276 polarity = PWM_POLARITY_INVERSED;
1277 else
1278 return -EINVAL;
1279
1280 guard(mutex)(&export->lock);
1281
1282 pwm_get_state(pwm, &state);
1283 state.polarity = polarity;
1284 ret = pwm_apply_might_sleep(pwm, &state);
1285
1286 return ret ? : size;
1287}
1288
1289static ssize_t capture_show(struct device *pwm_dev,
1290 struct device_attribute *attr,
1291 char *buf)
1292{
1293 struct pwm_device *pwm = pwm_from_dev(pwm_dev);
1294 struct pwm_capture result;
1295 int ret;
1296
1297 ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ));
1298 if (ret)
1299 return ret;
1300
1301 return sysfs_emit(buf, "%u %u\n", result.period, result.duty_cycle);
1302}
1303
1304static DEVICE_ATTR_RW(period);
1305static DEVICE_ATTR_RW(duty_cycle);
1306static DEVICE_ATTR_RW(enable);
1307static DEVICE_ATTR_RW(polarity);
1308static DEVICE_ATTR_RO(capture);
1309
1310static struct attribute *pwm_attrs[] = {
1311 &dev_attr_period.attr,
1312 &dev_attr_duty_cycle.attr,
1313 &dev_attr_enable.attr,
1314 &dev_attr_polarity.attr,
1315 &dev_attr_capture.attr,
1316 NULL
1317};
1318ATTRIBUTE_GROUPS(pwm);
1319
1320static void pwm_export_release(struct device *pwm_dev)
1321{
1322 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1323
1324 kfree(export);
1325}
1326
1327static int pwm_export_child(struct device *pwmchip_dev, struct pwm_device *pwm)
1328{
1329 struct pwm_export *export;
1330 char *pwm_prop[2];
1331 int ret;
1332
1333 if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags))
1334 return -EBUSY;
1335
1336 export = kzalloc_obj(*export);
1337 if (!export) {
1338 clear_bit(PWMF_EXPORTED, &pwm->flags);
1339 return -ENOMEM;
1340 }
1341
1342 export->pwm = pwm;
1343 mutex_init(&export->lock);
1344
1345 export->pwm_dev.release = pwm_export_release;
1346 export->pwm_dev.parent = pwmchip_dev;
1347 export->pwm_dev.devt = MKDEV(0, 0);
1348 export->pwm_dev.groups = pwm_groups;
1349 dev_set_name(&export->pwm_dev, "pwm%u", pwm->hwpwm);
1350
1351 ret = device_register(&export->pwm_dev);
1352 if (ret) {
1353 clear_bit(PWMF_EXPORTED, &pwm->flags);
1354 put_device(&export->pwm_dev);
1355 export = NULL;
1356 return ret;
1357 }
1358 pwm_prop[0] = kasprintf(GFP_KERNEL, "EXPORT=pwm%u", pwm->hwpwm);
1359 pwm_prop[1] = NULL;
1360 kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop);
1361 kfree(pwm_prop[0]);
1362
1363 return 0;
1364}
1365
1366static int pwm_unexport_match(struct device *pwm_dev, const void *data)
1367{
1368 return pwm_from_dev(pwm_dev) == data;
1369}
1370
1371static int pwm_unexport_child(struct device *pwmchip_dev, struct pwm_device *pwm)
1372{
1373 struct device *pwm_dev;
1374 char *pwm_prop[2];
1375
1376 if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags))
1377 return -ENODEV;
1378
1379 pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match);
1380 if (!pwm_dev)
1381 return -ENODEV;
1382
1383 pwm_prop[0] = kasprintf(GFP_KERNEL, "UNEXPORT=pwm%u", pwm->hwpwm);
1384 pwm_prop[1] = NULL;
1385 kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop);
1386 kfree(pwm_prop[0]);
1387
1388 /* for device_find_child() */
1389 put_device(pwm_dev);
1390 device_unregister(pwm_dev);
1391 pwm_put(pwm);
1392
1393 return 0;
1394}
1395
1396static ssize_t export_store(struct device *pwmchip_dev,
1397 struct device_attribute *attr,
1398 const char *buf, size_t len)
1399{
1400 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1401 struct pwm_device *pwm;
1402 unsigned int hwpwm;
1403 int ret;
1404
1405 ret = kstrtouint(buf, 0, &hwpwm);
1406 if (ret < 0)
1407 return ret;
1408
1409 if (hwpwm >= chip->npwm)
1410 return -ENODEV;
1411
1412 pwm = pwm_request_from_chip(chip, hwpwm, "sysfs");
1413 if (IS_ERR(pwm))
1414 return PTR_ERR(pwm);
1415
1416 ret = pwm_export_child(pwmchip_dev, pwm);
1417 if (ret < 0)
1418 pwm_put(pwm);
1419
1420 return ret ? : len;
1421}
1422static DEVICE_ATTR_WO(export);
1423
1424static ssize_t unexport_store(struct device *pwmchip_dev,
1425 struct device_attribute *attr,
1426 const char *buf, size_t len)
1427{
1428 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1429 unsigned int hwpwm;
1430 int ret;
1431
1432 ret = kstrtouint(buf, 0, &hwpwm);
1433 if (ret < 0)
1434 return ret;
1435
1436 if (hwpwm >= chip->npwm)
1437 return -ENODEV;
1438
1439 ret = pwm_unexport_child(pwmchip_dev, &chip->pwms[hwpwm]);
1440
1441 return ret ? : len;
1442}
1443static DEVICE_ATTR_WO(unexport);
1444
1445static ssize_t npwm_show(struct device *pwmchip_dev, struct device_attribute *attr,
1446 char *buf)
1447{
1448 const struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1449
1450 return sysfs_emit(buf, "%u\n", chip->npwm);
1451}
1452static DEVICE_ATTR_RO(npwm);
1453
1454static struct attribute *pwm_chip_attrs[] = {
1455 &dev_attr_export.attr,
1456 &dev_attr_unexport.attr,
1457 &dev_attr_npwm.attr,
1458 NULL,
1459};
1460ATTRIBUTE_GROUPS(pwm_chip);
1461
1462/* takes export->lock on success */
1463static struct pwm_export *pwm_class_get_state(struct device *pwmchip_dev,
1464 struct pwm_device *pwm,
1465 struct pwm_state *state)
1466{
1467 struct device *pwm_dev;
1468 struct pwm_export *export;
1469
1470 if (!test_bit(PWMF_EXPORTED, &pwm->flags))
1471 return NULL;
1472
1473 pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match);
1474 if (!pwm_dev)
1475 return NULL;
1476
1477 export = pwmexport_from_dev(pwm_dev);
1478 put_device(pwm_dev); /* for device_find_child() */
1479
1480 mutex_lock(&export->lock);
1481 pwm_get_state(pwm, state);
1482
1483 return export;
1484}
1485
1486static int pwm_class_apply_state(struct pwm_export *export,
1487 struct pwm_device *pwm,
1488 struct pwm_state *state)
1489{
1490 int ret = pwm_apply_might_sleep(pwm, state);
1491
1492 /* release lock taken in pwm_class_get_state */
1493 mutex_unlock(&export->lock);
1494
1495 return ret;
1496}
1497
1498static int pwm_class_resume_npwm(struct device *pwmchip_dev, unsigned int npwm)
1499{
1500 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1501 unsigned int i;
1502 int ret = 0;
1503
1504 for (i = 0; i < npwm; i++) {
1505 struct pwm_device *pwm = &chip->pwms[i];
1506 struct pwm_state state;
1507 struct pwm_export *export;
1508
1509 export = pwm_class_get_state(pwmchip_dev, pwm, &state);
1510 if (!export)
1511 continue;
1512
1513 /* If pwmchip was not enabled before suspend, do nothing. */
1514 if (!export->suspend.enabled) {
1515 /* release lock taken in pwm_class_get_state */
1516 mutex_unlock(&export->lock);
1517 continue;
1518 }
1519
1520 state.enabled = export->suspend.enabled;
1521 ret = pwm_class_apply_state(export, pwm, &state);
1522 if (ret < 0)
1523 break;
1524 }
1525
1526 return ret;
1527}
1528
1529static int pwm_class_suspend(struct device *pwmchip_dev)
1530{
1531 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1532 unsigned int i;
1533 int ret = 0;
1534
1535 for (i = 0; i < chip->npwm; i++) {
1536 struct pwm_device *pwm = &chip->pwms[i];
1537 struct pwm_state state;
1538 struct pwm_export *export;
1539
1540 export = pwm_class_get_state(pwmchip_dev, pwm, &state);
1541 if (!export)
1542 continue;
1543
1544 /*
1545 * If pwmchip was not enabled before suspend, save
1546 * state for resume time and do nothing else.
1547 */
1548 export->suspend = state;
1549 if (!state.enabled) {
1550 /* release lock taken in pwm_class_get_state */
1551 mutex_unlock(&export->lock);
1552 continue;
1553 }
1554
1555 state.enabled = false;
1556 ret = pwm_class_apply_state(export, pwm, &state);
1557 if (ret < 0) {
1558 /*
1559 * roll back the PWM devices that were disabled by
1560 * this suspend function.
1561 */
1562 pwm_class_resume_npwm(pwmchip_dev, i);
1563 break;
1564 }
1565 }
1566
1567 return ret;
1568}
1569
1570static int pwm_class_resume(struct device *pwmchip_dev)
1571{
1572 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1573
1574 return pwm_class_resume_npwm(pwmchip_dev, chip->npwm);
1575}
1576
1577static DEFINE_SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume);
1578
1579static struct class pwm_class = {
1580 .name = "pwm",
1581 .dev_groups = pwm_chip_groups,
1582 .pm = pm_sleep_ptr(&pwm_class_pm_ops),
1583};
1584
1585static void pwmchip_sysfs_unexport(struct pwm_chip *chip)
1586{
1587 unsigned int i;
1588
1589 for (i = 0; i < chip->npwm; i++) {
1590 struct pwm_device *pwm = &chip->pwms[i];
1591
1592 if (test_bit(PWMF_EXPORTED, &pwm->flags))
1593 pwm_unexport_child(&chip->dev, pwm);
1594 }
1595}
1596
1597#define PWMCHIP_ALIGN ARCH_DMA_MINALIGN
1598
1599static void *pwmchip_priv(struct pwm_chip *chip)
1600{
1601 return (void *)chip + ALIGN(struct_size(chip, pwms, chip->npwm), PWMCHIP_ALIGN);
1602}
1603
1604/* This is the counterpart to pwmchip_alloc() */
1605void pwmchip_put(struct pwm_chip *chip)
1606{
1607 put_device(&chip->dev);
1608}
1609EXPORT_SYMBOL_GPL(pwmchip_put);
1610
1611void pwmchip_release(struct device *pwmchip_dev)
1612{
1613 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1614
1615 kfree(chip);
1616}
1617EXPORT_SYMBOL_GPL(pwmchip_release);
1618
1619struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv)
1620{
1621 struct pwm_chip *chip;
1622 struct device *pwmchip_dev;
1623 size_t alloc_size;
1624 unsigned int i;
1625
1626 alloc_size = size_add(ALIGN(struct_size(chip, pwms, npwm), PWMCHIP_ALIGN),
1627 sizeof_priv);
1628
1629 chip = kzalloc(alloc_size, GFP_KERNEL);
1630 if (!chip)
1631 return ERR_PTR(-ENOMEM);
1632
1633 chip->npwm = npwm;
1634 chip->uses_pwmchip_alloc = true;
1635 chip->operational = false;
1636
1637 pwmchip_dev = &chip->dev;
1638 device_initialize(pwmchip_dev);
1639 pwmchip_dev->class = &pwm_class;
1640 pwmchip_dev->parent = parent;
1641 pwmchip_dev->release = pwmchip_release;
1642
1643 pwmchip_set_drvdata(chip, pwmchip_priv(chip));
1644
1645 for (i = 0; i < chip->npwm; i++) {
1646 struct pwm_device *pwm = &chip->pwms[i];
1647 pwm->chip = chip;
1648 pwm->hwpwm = i;
1649 }
1650
1651 return chip;
1652}
1653EXPORT_SYMBOL_GPL(pwmchip_alloc);
1654
1655static void devm_pwmchip_put(void *data)
1656{
1657 struct pwm_chip *chip = data;
1658
1659 pwmchip_put(chip);
1660}
1661
1662struct pwm_chip *devm_pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv)
1663{
1664 struct pwm_chip *chip;
1665 int ret;
1666
1667 chip = pwmchip_alloc(parent, npwm, sizeof_priv);
1668 if (IS_ERR(chip))
1669 return chip;
1670
1671 ret = devm_add_action_or_reset(parent, devm_pwmchip_put, chip);
1672 if (ret)
1673 return ERR_PTR(ret);
1674
1675 return chip;
1676}
1677EXPORT_SYMBOL_GPL(devm_pwmchip_alloc);
1678
1679static void of_pwmchip_add(struct pwm_chip *chip)
1680{
1681 if (!pwmchip_parent(chip) || !pwmchip_parent(chip)->of_node)
1682 return;
1683
1684 if (!chip->of_xlate)
1685 chip->of_xlate = of_pwm_xlate_with_flags;
1686
1687 of_node_get(pwmchip_parent(chip)->of_node);
1688}
1689
1690static void of_pwmchip_remove(struct pwm_chip *chip)
1691{
1692 if (pwmchip_parent(chip))
1693 of_node_put(pwmchip_parent(chip)->of_node);
1694}
1695
1696static bool pwm_ops_check(const struct pwm_chip *chip)
1697{
1698 const struct pwm_ops *ops = chip->ops;
1699
1700 if (ops->write_waveform) {
1701 if (!ops->round_waveform_tohw ||
1702 !ops->round_waveform_fromhw)
1703 return false;
1704
1705 if (PWM_WFHWSIZE < ops->sizeof_wfhw) {
1706 dev_warn(pwmchip_parent(chip), "PWM_WFHWSIZE < %zu\n", ops->sizeof_wfhw);
1707 return false;
1708 }
1709 } else {
1710 if (!ops->apply)
1711 return false;
1712
1713 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
1714 dev_warn(pwmchip_parent(chip),
1715 "Please implement the .get_state() callback\n");
1716 }
1717
1718 return true;
1719}
1720
1721static struct device_link *pwm_device_link_add(struct device *dev,
1722 struct pwm_device *pwm)
1723{
1724 struct device_link *dl;
1725
1726 if (!dev) {
1727 /*
1728 * No device for the PWM consumer has been provided. It may
1729 * impact the PM sequence ordering: the PWM supplier may get
1730 * suspended before the consumer.
1731 */
1732 dev_warn(pwmchip_parent(pwm->chip),
1733 "No consumer device specified to create a link to\n");
1734 return NULL;
1735 }
1736
1737 dl = device_link_add(dev, pwmchip_parent(pwm->chip), DL_FLAG_AUTOREMOVE_CONSUMER);
1738 if (!dl) {
1739 dev_err(dev, "failed to create device link to %s\n",
1740 dev_name(pwmchip_parent(pwm->chip)));
1741 return ERR_PTR(-EINVAL);
1742 }
1743
1744 return dl;
1745}
1746
1747static struct pwm_chip *fwnode_to_pwmchip(struct fwnode_handle *fwnode)
1748{
1749 struct pwm_chip *chip;
1750 unsigned long id, tmp;
1751
1752 guard(mutex)(&pwm_lock);
1753
1754 idr_for_each_entry_ul(&pwm_chips, chip, tmp, id)
1755 if (pwmchip_parent(chip) && device_match_fwnode(pwmchip_parent(chip), fwnode))
1756 return chip;
1757
1758 return ERR_PTR(-EPROBE_DEFER);
1759}
1760
1761/**
1762 * of_pwm_get() - request a PWM via the PWM framework
1763 * @dev: device for PWM consumer
1764 * @np: device node to get the PWM from
1765 * @con_id: consumer name
1766 *
1767 * Returns the PWM device parsed from the phandle and index specified in the
1768 * "pwms" property of a device tree node or a negative error-code on failure.
1769 * Values parsed from the device tree are stored in the returned PWM device
1770 * object.
1771 *
1772 * If con_id is NULL, the first PWM device listed in the "pwms" property will
1773 * be requested. Otherwise the "pwm-names" property is used to do a reverse
1774 * lookup of the PWM index. This also means that the "pwm-names" property
1775 * becomes mandatory for devices that look up the PWM device via the con_id
1776 * parameter.
1777 *
1778 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1779 * error code on failure.
1780 */
1781static struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
1782 const char *con_id)
1783{
1784 struct pwm_device *pwm = NULL;
1785 struct of_phandle_args args;
1786 struct device_link *dl;
1787 struct pwm_chip *chip;
1788 int index = 0;
1789 int err;
1790
1791 if (con_id) {
1792 index = of_property_match_string(np, "pwm-names", con_id);
1793 if (index < 0)
1794 return ERR_PTR(index);
1795 }
1796
1797 err = of_parse_phandle_with_args_map(np, "pwms", "pwm", index, &args);
1798 if (err) {
1799 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
1800 return ERR_PTR(err);
1801 }
1802
1803 chip = fwnode_to_pwmchip(of_fwnode_handle(args.np));
1804 if (IS_ERR(chip)) {
1805 if (PTR_ERR(chip) != -EPROBE_DEFER)
1806 pr_err("%s(): PWM chip not found\n", __func__);
1807
1808 pwm = ERR_CAST(chip);
1809 goto put;
1810 }
1811
1812 pwm = chip->of_xlate(chip, &args);
1813 if (IS_ERR(pwm))
1814 goto put;
1815
1816 dl = pwm_device_link_add(dev, pwm);
1817 if (IS_ERR(dl)) {
1818 /* of_xlate ended up calling pwm_request_from_chip() */
1819 pwm_put(pwm);
1820 pwm = ERR_CAST(dl);
1821 goto put;
1822 }
1823
1824 /*
1825 * If a consumer name was not given, try to look it up from the
1826 * "pwm-names" property if it exists. Otherwise use the name of
1827 * the user device node.
1828 */
1829 if (!con_id) {
1830 err = of_property_read_string_index(np, "pwm-names", index,
1831 &con_id);
1832 if (err < 0)
1833 con_id = np->name;
1834 }
1835
1836 pwm->label = con_id;
1837
1838put:
1839 of_node_put(args.np);
1840
1841 return pwm;
1842}
1843
1844/**
1845 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
1846 * @fwnode: firmware node to get the "pwms" property from
1847 *
1848 * Returns the PWM device parsed from the fwnode and index specified in the
1849 * "pwms" property or a negative error-code on failure.
1850 * Values parsed from the device tree are stored in the returned PWM device
1851 * object.
1852 *
1853 * This is analogous to of_pwm_get() except con_id is not yet supported.
1854 * ACPI entries must look like
1855 * Package () {"pwms", Package ()
1856 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
1857 *
1858 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1859 * error code on failure.
1860 */
1861static struct pwm_device *acpi_pwm_get(const struct fwnode_handle *fwnode)
1862{
1863 struct pwm_device *pwm;
1864 struct fwnode_reference_args args;
1865 struct pwm_chip *chip;
1866 int ret;
1867
1868 memset(&args, 0, sizeof(args));
1869
1870 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
1871 if (ret < 0)
1872 return ERR_PTR(ret);
1873
1874 if (args.nargs < 2)
1875 return ERR_PTR(-EPROTO);
1876
1877 chip = fwnode_to_pwmchip(args.fwnode);
1878 if (IS_ERR(chip))
1879 return ERR_CAST(chip);
1880
1881 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
1882 if (IS_ERR(pwm))
1883 return pwm;
1884
1885 pwm->args.period = args.args[1];
1886 pwm->args.polarity = PWM_POLARITY_NORMAL;
1887
1888 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
1889 pwm->args.polarity = PWM_POLARITY_INVERSED;
1890
1891 return pwm;
1892}
1893
1894static DEFINE_MUTEX(pwm_lookup_lock);
1895static LIST_HEAD(pwm_lookup_list);
1896
1897/**
1898 * pwm_get() - look up and request a PWM device
1899 * @dev: device for PWM consumer
1900 * @con_id: consumer name
1901 *
1902 * Lookup is first attempted using DT. If the device was not instantiated from
1903 * a device tree, a PWM chip and a relative index is looked up via a table
1904 * supplied by board setup code (see pwm_add_table()).
1905 *
1906 * Once a PWM chip has been found the specified PWM device will be requested
1907 * and is ready to be used.
1908 *
1909 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1910 * error code on failure.
1911 */
1912struct pwm_device *pwm_get(struct device *dev, const char *con_id)
1913{
1914 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
1915 const char *dev_id = dev ? dev_name(dev) : NULL;
1916 struct pwm_device *pwm;
1917 struct pwm_chip *chip;
1918 struct device_link *dl;
1919 unsigned int best = 0;
1920 struct pwm_lookup *p, *chosen = NULL;
1921 unsigned int match;
1922 int err;
1923
1924 /* look up via DT first */
1925 if (is_of_node(fwnode))
1926 return of_pwm_get(dev, to_of_node(fwnode), con_id);
1927
1928 /* then lookup via ACPI */
1929 if (is_acpi_node(fwnode)) {
1930 pwm = acpi_pwm_get(fwnode);
1931 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
1932 return pwm;
1933 }
1934
1935 /*
1936 * We look up the provider in the static table typically provided by
1937 * board setup code. We first try to lookup the consumer device by
1938 * name. If the consumer device was passed in as NULL or if no match
1939 * was found, we try to find the consumer by directly looking it up
1940 * by name.
1941 *
1942 * If a match is found, the provider PWM chip is looked up by name
1943 * and a PWM device is requested using the PWM device per-chip index.
1944 *
1945 * The lookup algorithm was shamelessly taken from the clock
1946 * framework:
1947 *
1948 * We do slightly fuzzy matching here:
1949 * An entry with a NULL ID is assumed to be a wildcard.
1950 * If an entry has a device ID, it must match
1951 * If an entry has a connection ID, it must match
1952 * Then we take the most specific entry - with the following order
1953 * of precedence: dev+con > dev only > con only.
1954 */
1955 scoped_guard(mutex, &pwm_lookup_lock)
1956 list_for_each_entry(p, &pwm_lookup_list, list) {
1957 match = 0;
1958
1959 if (p->dev_id) {
1960 if (!dev_id || strcmp(p->dev_id, dev_id))
1961 continue;
1962
1963 match += 2;
1964 }
1965
1966 if (p->con_id) {
1967 if (!con_id || strcmp(p->con_id, con_id))
1968 continue;
1969
1970 match += 1;
1971 }
1972
1973 if (match > best) {
1974 chosen = p;
1975
1976 if (match != 3)
1977 best = match;
1978 else
1979 break;
1980 }
1981 }
1982
1983 if (!chosen)
1984 return ERR_PTR(-ENODEV);
1985
1986 chip = pwmchip_find_by_name(chosen->provider);
1987
1988 /*
1989 * If the lookup entry specifies a module, load the module and retry
1990 * the PWM chip lookup. This can be used to work around driver load
1991 * ordering issues if driver's can't be made to properly support the
1992 * deferred probe mechanism.
1993 */
1994 if (!chip && chosen->module) {
1995 err = request_module(chosen->module);
1996 if (err == 0)
1997 chip = pwmchip_find_by_name(chosen->provider);
1998 }
1999
2000 if (!chip)
2001 return ERR_PTR(-EPROBE_DEFER);
2002
2003 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
2004 if (IS_ERR(pwm))
2005 return pwm;
2006
2007 dl = pwm_device_link_add(dev, pwm);
2008 if (IS_ERR(dl)) {
2009 pwm_put(pwm);
2010 return ERR_CAST(dl);
2011 }
2012
2013 pwm->args.period = chosen->period;
2014 pwm->args.polarity = chosen->polarity;
2015
2016 return pwm;
2017}
2018EXPORT_SYMBOL_GPL(pwm_get);
2019
2020static void __pwm_put(struct pwm_device *pwm)
2021{
2022 struct pwm_chip *chip = pwm->chip;
2023
2024 /*
2025 * Trigger a warning if a consumer called pwm_put() twice.
2026 * If the chip isn't operational, PWMF_REQUESTED was already cleared in
2027 * pwmchip_remove(). So don't warn in this case.
2028 */
2029 if (chip->operational && !test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
2030 pr_warn("PWM device already freed\n");
2031 return;
2032 }
2033
2034 if (chip->operational && chip->ops->free)
2035 pwm->chip->ops->free(pwm->chip, pwm);
2036
2037 pwm->label = NULL;
2038
2039 put_device(&chip->dev);
2040
2041 module_put(chip->owner);
2042}
2043
2044/**
2045 * pwm_put() - release a PWM device
2046 * @pwm: PWM device
2047 */
2048void pwm_put(struct pwm_device *pwm)
2049{
2050 if (!pwm)
2051 return;
2052
2053 guard(mutex)(&pwm_lock);
2054
2055 __pwm_put(pwm);
2056}
2057EXPORT_SYMBOL_GPL(pwm_put);
2058
2059static void devm_pwm_release(void *pwm)
2060{
2061 pwm_put(pwm);
2062}
2063
2064/**
2065 * devm_pwm_get() - resource managed pwm_get()
2066 * @dev: device for PWM consumer
2067 * @con_id: consumer name
2068 *
2069 * This function performs like pwm_get() but the acquired PWM device will
2070 * automatically be released on driver detach.
2071 *
2072 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
2073 * error code on failure.
2074 */
2075struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
2076{
2077 struct pwm_device *pwm;
2078 int ret;
2079
2080 pwm = pwm_get(dev, con_id);
2081 if (IS_ERR(pwm))
2082 return pwm;
2083
2084 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
2085 if (ret)
2086 return ERR_PTR(ret);
2087
2088 return pwm;
2089}
2090EXPORT_SYMBOL_GPL(devm_pwm_get);
2091
2092/**
2093 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
2094 * @dev: device for PWM consumer
2095 * @fwnode: firmware node to get the PWM from
2096 * @con_id: consumer name
2097 *
2098 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
2099 * acpi_pwm_get() for a detailed description.
2100 *
2101 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
2102 * error code on failure.
2103 */
2104struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
2105 struct fwnode_handle *fwnode,
2106 const char *con_id)
2107{
2108 struct pwm_device *pwm = ERR_PTR(-ENODEV);
2109 int ret;
2110
2111 if (is_of_node(fwnode))
2112 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
2113 else if (is_acpi_node(fwnode))
2114 pwm = acpi_pwm_get(fwnode);
2115 if (IS_ERR(pwm))
2116 return pwm;
2117
2118 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
2119 if (ret)
2120 return ERR_PTR(ret);
2121
2122 return pwm;
2123}
2124EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
2125
2126struct pwm_cdev_data {
2127 struct pwm_chip *chip;
2128 struct pwm_device *pwm[];
2129};
2130
2131static int pwm_cdev_open(struct inode *inode, struct file *file)
2132{
2133 struct pwm_chip *chip = container_of(inode->i_cdev, struct pwm_chip, cdev);
2134 struct pwm_cdev_data *cdata;
2135
2136 guard(mutex)(&pwm_lock);
2137
2138 if (!chip->operational)
2139 return -ENXIO;
2140
2141 cdata = kzalloc_flex(*cdata, pwm, chip->npwm);
2142 if (!cdata)
2143 return -ENOMEM;
2144
2145 cdata->chip = chip;
2146
2147 file->private_data = cdata;
2148
2149 return nonseekable_open(inode, file);
2150}
2151
2152static int pwm_cdev_release(struct inode *inode, struct file *file)
2153{
2154 struct pwm_cdev_data *cdata = file->private_data;
2155 unsigned int i;
2156
2157 for (i = 0; i < cdata->chip->npwm; ++i) {
2158 struct pwm_device *pwm = cdata->pwm[i];
2159
2160 if (pwm) {
2161 const char *label = pwm->label;
2162
2163 pwm_put(cdata->pwm[i]);
2164 kfree(label);
2165 }
2166 }
2167 kfree(cdata);
2168
2169 return 0;
2170}
2171
2172static int pwm_cdev_request(struct pwm_cdev_data *cdata, unsigned int hwpwm)
2173{
2174 struct pwm_chip *chip = cdata->chip;
2175
2176 if (hwpwm >= chip->npwm)
2177 return -EINVAL;
2178
2179 if (!cdata->pwm[hwpwm]) {
2180 struct pwm_device *pwm = &chip->pwms[hwpwm];
2181 const char *label;
2182 int ret;
2183
2184 label = kasprintf(GFP_KERNEL, "pwm-cdev (pid=%d)", current->pid);
2185 if (!label)
2186 return -ENOMEM;
2187
2188 ret = pwm_device_request(pwm, label);
2189 if (ret < 0) {
2190 kfree(label);
2191 return ret;
2192 }
2193
2194 cdata->pwm[hwpwm] = pwm;
2195 }
2196
2197 return 0;
2198}
2199
2200static int pwm_cdev_free(struct pwm_cdev_data *cdata, unsigned int hwpwm)
2201{
2202 struct pwm_chip *chip = cdata->chip;
2203
2204 if (hwpwm >= chip->npwm)
2205 return -EINVAL;
2206
2207 if (cdata->pwm[hwpwm]) {
2208 struct pwm_device *pwm = cdata->pwm[hwpwm];
2209 const char *label = pwm->label;
2210
2211 __pwm_put(pwm);
2212
2213 kfree(label);
2214
2215 cdata->pwm[hwpwm] = NULL;
2216 }
2217
2218 return 0;
2219}
2220
2221static struct pwm_device *pwm_cdev_get_requested_pwm(struct pwm_cdev_data *cdata,
2222 u32 hwpwm)
2223{
2224 struct pwm_chip *chip = cdata->chip;
2225
2226 if (hwpwm >= chip->npwm)
2227 return ERR_PTR(-EINVAL);
2228
2229 if (cdata->pwm[hwpwm])
2230 return cdata->pwm[hwpwm];
2231
2232 return ERR_PTR(-EINVAL);
2233}
2234
2235static long pwm_cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2236{
2237 int ret = 0;
2238 struct pwm_cdev_data *cdata = file->private_data;
2239 struct pwm_chip *chip = cdata->chip;
2240
2241 guard(mutex)(&pwm_lock);
2242
2243 if (!chip->operational)
2244 return -ENODEV;
2245
2246 switch (cmd) {
2247 case PWM_IOCTL_REQUEST:
2248 {
2249 unsigned int hwpwm = arg;
2250
2251 return pwm_cdev_request(cdata, hwpwm);
2252 }
2253
2254 case PWM_IOCTL_FREE:
2255 {
2256 unsigned int hwpwm = arg;
2257
2258 return pwm_cdev_free(cdata, hwpwm);
2259 }
2260
2261 case PWM_IOCTL_ROUNDWF:
2262 {
2263 struct pwmchip_waveform cwf;
2264 struct pwm_waveform wf;
2265 struct pwm_device *pwm;
2266
2267 ret = copy_from_user(&cwf,
2268 (struct pwmchip_waveform __user *)arg,
2269 sizeof(cwf));
2270 if (ret)
2271 return -EFAULT;
2272
2273 if (cwf.__pad != 0)
2274 return -EINVAL;
2275
2276 pwm = pwm_cdev_get_requested_pwm(cdata, cwf.hwpwm);
2277 if (IS_ERR(pwm))
2278 return PTR_ERR(pwm);
2279
2280 wf = (struct pwm_waveform) {
2281 .period_length_ns = cwf.period_length_ns,
2282 .duty_length_ns = cwf.duty_length_ns,
2283 .duty_offset_ns = cwf.duty_offset_ns,
2284 };
2285
2286 ret = pwm_round_waveform_might_sleep(pwm, &wf);
2287 if (ret < 0)
2288 return ret;
2289
2290 cwf = (struct pwmchip_waveform) {
2291 .hwpwm = cwf.hwpwm,
2292 .period_length_ns = wf.period_length_ns,
2293 .duty_length_ns = wf.duty_length_ns,
2294 .duty_offset_ns = wf.duty_offset_ns,
2295 };
2296
2297 ret = copy_to_user((struct pwmchip_waveform __user *)arg,
2298 &cwf, sizeof(cwf));
2299 return ret ? -EFAULT : 0;
2300 }
2301
2302 case PWM_IOCTL_GETWF:
2303 {
2304 struct pwmchip_waveform cwf;
2305 struct pwm_waveform wf;
2306 struct pwm_device *pwm;
2307
2308 ret = copy_from_user(&cwf,
2309 (struct pwmchip_waveform __user *)arg,
2310 sizeof(cwf));
2311 if (ret)
2312 return -EFAULT;
2313
2314 if (cwf.__pad != 0)
2315 return -EINVAL;
2316
2317 pwm = pwm_cdev_get_requested_pwm(cdata, cwf.hwpwm);
2318 if (IS_ERR(pwm))
2319 return PTR_ERR(pwm);
2320
2321 ret = pwm_get_waveform_might_sleep(pwm, &wf);
2322 if (ret)
2323 return ret;
2324
2325 cwf = (struct pwmchip_waveform) {
2326 .hwpwm = cwf.hwpwm,
2327 .period_length_ns = wf.period_length_ns,
2328 .duty_length_ns = wf.duty_length_ns,
2329 .duty_offset_ns = wf.duty_offset_ns,
2330 };
2331
2332 ret = copy_to_user((struct pwmchip_waveform __user *)arg,
2333 &cwf, sizeof(cwf));
2334 return ret ? -EFAULT : 0;
2335 }
2336
2337 case PWM_IOCTL_SETROUNDEDWF:
2338 case PWM_IOCTL_SETEXACTWF:
2339 {
2340 struct pwmchip_waveform cwf;
2341 struct pwm_waveform wf;
2342 struct pwm_device *pwm;
2343
2344 ret = copy_from_user(&cwf,
2345 (struct pwmchip_waveform __user *)arg,
2346 sizeof(cwf));
2347 if (ret)
2348 return -EFAULT;
2349
2350 if (cwf.__pad != 0)
2351 return -EINVAL;
2352
2353 wf = (struct pwm_waveform){
2354 .period_length_ns = cwf.period_length_ns,
2355 .duty_length_ns = cwf.duty_length_ns,
2356 .duty_offset_ns = cwf.duty_offset_ns,
2357 };
2358
2359 if (!pwm_wf_valid(&wf))
2360 return -EINVAL;
2361
2362 pwm = pwm_cdev_get_requested_pwm(cdata, cwf.hwpwm);
2363 if (IS_ERR(pwm))
2364 return PTR_ERR(pwm);
2365
2366 ret = pwm_set_waveform_might_sleep(pwm, &wf,
2367 cmd == PWM_IOCTL_SETEXACTWF);
2368
2369 /*
2370 * If userspace cares about rounding deviations it has
2371 * to check the values anyhow, so simplify handling for
2372 * them and don't signal uprounding. This matches the
2373 * behaviour of PWM_IOCTL_ROUNDWF which also returns 0
2374 * in that case.
2375 */
2376 if (ret == 1)
2377 ret = 0;
2378
2379 return ret;
2380 }
2381
2382 default:
2383 return -ENOTTY;
2384 }
2385}
2386
2387static const struct file_operations pwm_cdev_fileops = {
2388 .open = pwm_cdev_open,
2389 .release = pwm_cdev_release,
2390 .owner = THIS_MODULE,
2391 .unlocked_ioctl = pwm_cdev_ioctl,
2392};
2393
2394static dev_t pwm_devt;
2395
2396static int pwm_gpio_request(struct gpio_chip *gc, unsigned int offset)
2397{
2398 struct pwm_chip *chip = gpiochip_get_data(gc);
2399 struct pwm_device *pwm;
2400
2401 pwm = pwm_request_from_chip(chip, offset, "pwm-gpio");
2402 if (IS_ERR(pwm))
2403 return PTR_ERR(pwm);
2404
2405 return 0;
2406}
2407
2408static void pwm_gpio_free(struct gpio_chip *gc, unsigned int offset)
2409{
2410 struct pwm_chip *chip = gpiochip_get_data(gc);
2411
2412 pwm_put(&chip->pwms[offset]);
2413}
2414
2415static int pwm_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
2416{
2417 return GPIO_LINE_DIRECTION_OUT;
2418}
2419
2420static int pwm_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
2421{
2422 struct pwm_chip *chip = gpiochip_get_data(gc);
2423 struct pwm_device *pwm = &chip->pwms[offset];
2424 int ret;
2425 struct pwm_waveform wf = {
2426 .period_length_ns = 1,
2427 };
2428
2429 ret = pwm_round_waveform_might_sleep(pwm, &wf);
2430 if (ret < 0)
2431 return ret;
2432
2433 if (value)
2434 wf.duty_length_ns = wf.period_length_ns;
2435 else
2436 wf.duty_length_ns = 0;
2437
2438 return pwm_set_waveform_might_sleep(pwm, &wf, true);
2439}
2440
2441/**
2442 * __pwmchip_add() - register a new PWM chip
2443 * @chip: the PWM chip to add
2444 * @owner: reference to the module providing the chip.
2445 *
2446 * Register a new PWM chip. @owner is supposed to be THIS_MODULE, use the
2447 * pwmchip_add wrapper to do this right.
2448 *
2449 * Returns: 0 on success or a negative error code on failure.
2450 */
2451int __pwmchip_add(struct pwm_chip *chip, struct module *owner)
2452{
2453 int ret;
2454
2455 if (!chip || !pwmchip_parent(chip) || !chip->ops || !chip->npwm)
2456 return -EINVAL;
2457
2458 /*
2459 * a struct pwm_chip must be allocated using (devm_)pwmchip_alloc,
2460 * otherwise the embedded struct device might disappear too early
2461 * resulting in memory corruption.
2462 * Catch drivers that were not converted appropriately.
2463 */
2464 if (!chip->uses_pwmchip_alloc)
2465 return -EINVAL;
2466
2467 if (!pwm_ops_check(chip))
2468 return -EINVAL;
2469
2470 chip->owner = owner;
2471
2472 if (chip->atomic)
2473 spin_lock_init(&chip->atomic_lock);
2474 else
2475 mutex_init(&chip->nonatomic_lock);
2476
2477 guard(mutex)(&pwm_lock);
2478
2479 ret = idr_alloc(&pwm_chips, chip, 0, 0, GFP_KERNEL);
2480 if (ret < 0)
2481 return ret;
2482
2483 chip->id = ret;
2484
2485 dev_set_name(&chip->dev, "pwmchip%u", chip->id);
2486
2487 if (IS_ENABLED(CONFIG_OF))
2488 of_pwmchip_add(chip);
2489
2490 scoped_guard(pwmchip, chip)
2491 chip->operational = true;
2492
2493 if (chip->ops->write_waveform) {
2494 if (chip->id < PWM_MINOR_COUNT)
2495 chip->dev.devt = MKDEV(MAJOR(pwm_devt), chip->id);
2496 else
2497 dev_warn(&chip->dev, "chip id too high to create a chardev\n");
2498 }
2499
2500 cdev_init(&chip->cdev, &pwm_cdev_fileops);
2501 chip->cdev.owner = owner;
2502
2503 ret = cdev_device_add(&chip->cdev, &chip->dev);
2504 if (ret)
2505 goto err_device_add;
2506
2507 if (IS_ENABLED(CONFIG_PWM_PROVIDE_GPIO) && chip->ops->write_waveform) {
2508 struct device *parent = pwmchip_parent(chip);
2509
2510 chip->gpio = (typeof(chip->gpio)){
2511 .label = dev_name(parent),
2512 .parent = parent,
2513 .request = pwm_gpio_request,
2514 .free = pwm_gpio_free,
2515 .get_direction = pwm_gpio_get_direction,
2516 .set = pwm_gpio_set,
2517 .base = -1,
2518 .ngpio = chip->npwm,
2519 .can_sleep = true,
2520 };
2521
2522 ret = gpiochip_add_data(&chip->gpio, chip);
2523 if (ret)
2524 goto err_gpiochip_add;
2525 }
2526
2527 return 0;
2528
2529err_gpiochip_add:
2530
2531 cdev_device_del(&chip->cdev, &chip->dev);
2532err_device_add:
2533
2534 scoped_guard(pwmchip, chip)
2535 chip->operational = false;
2536
2537 if (IS_ENABLED(CONFIG_OF))
2538 of_pwmchip_remove(chip);
2539
2540 idr_remove(&pwm_chips, chip->id);
2541
2542 return ret;
2543}
2544EXPORT_SYMBOL_GPL(__pwmchip_add);
2545
2546/**
2547 * pwmchip_remove() - remove a PWM chip
2548 * @chip: the PWM chip to remove
2549 *
2550 * Removes a PWM chip.
2551 */
2552void pwmchip_remove(struct pwm_chip *chip)
2553{
2554 if (IS_ENABLED(CONFIG_PWM_PROVIDE_GPIO) && chip->ops->write_waveform)
2555 gpiochip_remove(&chip->gpio);
2556
2557 pwmchip_sysfs_unexport(chip);
2558
2559 scoped_guard(mutex, &pwm_lock) {
2560 unsigned int i;
2561
2562 scoped_guard(pwmchip, chip)
2563 chip->operational = false;
2564
2565 for (i = 0; i < chip->npwm; ++i) {
2566 struct pwm_device *pwm = &chip->pwms[i];
2567
2568 if (test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
2569 dev_warn(&chip->dev, "Freeing requested PWM #%u\n", i);
2570 if (pwm->chip->ops->free)
2571 pwm->chip->ops->free(pwm->chip, pwm);
2572 }
2573 }
2574
2575 if (IS_ENABLED(CONFIG_OF))
2576 of_pwmchip_remove(chip);
2577
2578 idr_remove(&pwm_chips, chip->id);
2579 }
2580
2581 cdev_device_del(&chip->cdev, &chip->dev);
2582}
2583EXPORT_SYMBOL_GPL(pwmchip_remove);
2584
2585static void devm_pwmchip_remove(void *data)
2586{
2587 struct pwm_chip *chip = data;
2588
2589 pwmchip_remove(chip);
2590}
2591
2592int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner)
2593{
2594 int ret;
2595
2596 ret = __pwmchip_add(chip, owner);
2597 if (ret)
2598 return ret;
2599
2600 return devm_add_action_or_reset(dev, devm_pwmchip_remove, chip);
2601}
2602EXPORT_SYMBOL_GPL(__devm_pwmchip_add);
2603
2604/**
2605 * pwm_add_table() - register PWM device consumers
2606 * @table: array of consumers to register
2607 * @num: number of consumers in table
2608 */
2609void pwm_add_table(struct pwm_lookup *table, size_t num)
2610{
2611 guard(mutex)(&pwm_lookup_lock);
2612
2613 while (num--) {
2614 list_add_tail(&table->list, &pwm_lookup_list);
2615 table++;
2616 }
2617}
2618
2619/**
2620 * pwm_remove_table() - unregister PWM device consumers
2621 * @table: array of consumers to unregister
2622 * @num: number of consumers in table
2623 */
2624void pwm_remove_table(struct pwm_lookup *table, size_t num)
2625{
2626 guard(mutex)(&pwm_lookup_lock);
2627
2628 while (num--) {
2629 list_del(&table->list);
2630 table++;
2631 }
2632}
2633
2634static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
2635{
2636 unsigned int i;
2637
2638 for (i = 0; i < chip->npwm; i++) {
2639 struct pwm_device *pwm = &chip->pwms[i];
2640 struct pwm_state state;
2641 int err;
2642
2643 pwm_get_state(pwm, &state);
2644
2645 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
2646
2647 if (test_bit(PWMF_REQUESTED, &pwm->flags))
2648 seq_puts(s, " requested");
2649
2650 seq_putc(s, '\n');
2651
2652 seq_printf(s, " requested configuration: %3sabled, %llu/%llu ns, %s polarity",
2653 state.enabled ? "en" : "dis", state.duty_cycle, state.period,
2654 state.polarity ? "inverse" : "normal");
2655 if (state.usage_power)
2656 seq_puts(s, ", usage_power");
2657 seq_putc(s, '\n');
2658
2659 if (pwmchip_supports_waveform(chip)) {
2660 struct pwm_waveform wf;
2661
2662 err = pwm_get_waveform_might_sleep(pwm, &wf);
2663 if (!err)
2664 seq_printf(s, " actual configuration: %lld/%lld [+%lld]",
2665 wf.duty_length_ns, wf.period_length_ns, wf.duty_offset_ns);
2666 else
2667 seq_printf(s, " actual configuration: read out error: %pe\n", ERR_PTR(err));
2668 } else {
2669 struct pwm_state hwstate;
2670
2671 err = pwm_get_state_hw(pwm, &hwstate);
2672 if (!err)
2673 seq_printf(s, " actual configuration: %3sabled, %llu/%llu ns, %s polarity",
2674 hwstate.enabled ? "en" : "dis", hwstate.duty_cycle, hwstate.period,
2675 hwstate.polarity ? "inverse" : "normal");
2676 else
2677 seq_printf(s, " actual configuration: read out error: %pe", ERR_PTR(err));
2678 }
2679
2680 seq_putc(s, '\n');
2681 }
2682}
2683
2684static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
2685{
2686 unsigned long id = *pos;
2687 void *ret;
2688
2689 mutex_lock(&pwm_lock);
2690 s->private = "";
2691
2692 ret = idr_get_next_ul(&pwm_chips, &id);
2693 *pos = id;
2694 return ret;
2695}
2696
2697static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
2698{
2699 unsigned long id = *pos + 1;
2700 void *ret;
2701
2702 s->private = "\n";
2703
2704 ret = idr_get_next_ul(&pwm_chips, &id);
2705 *pos = id;
2706 return ret;
2707}
2708
2709static void pwm_seq_stop(struct seq_file *s, void *v)
2710{
2711 mutex_unlock(&pwm_lock);
2712}
2713
2714static int pwm_seq_show(struct seq_file *s, void *v)
2715{
2716 struct pwm_chip *chip = v;
2717
2718 seq_printf(s, "%s%u: %s/%s, npwm: %u\n",
2719 (char *)s->private, chip->id,
2720 pwmchip_parent(chip)->bus ? pwmchip_parent(chip)->bus->name : "no-bus",
2721 dev_name(pwmchip_parent(chip)), chip->npwm);
2722
2723 pwm_dbg_show(chip, s);
2724
2725 return 0;
2726}
2727
2728static const struct seq_operations pwm_debugfs_sops = {
2729 .start = pwm_seq_start,
2730 .next = pwm_seq_next,
2731 .stop = pwm_seq_stop,
2732 .show = pwm_seq_show,
2733};
2734
2735DEFINE_SEQ_ATTRIBUTE(pwm_debugfs);
2736
2737static int __init pwm_init(void)
2738{
2739 int ret;
2740
2741 ret = alloc_chrdev_region(&pwm_devt, 0, PWM_MINOR_COUNT, "pwm");
2742 if (ret) {
2743 pr_err("Failed to initialize chrdev region for PWM usage\n");
2744 return ret;
2745 }
2746
2747 ret = class_register(&pwm_class);
2748 if (ret) {
2749 pr_err("Failed to initialize PWM class (%pe)\n", ERR_PTR(ret));
2750 unregister_chrdev_region(pwm_devt, 256);
2751 return ret;
2752 }
2753
2754 if (IS_ENABLED(CONFIG_DEBUG_FS))
2755 debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops);
2756
2757 return 0;
2758}
2759subsys_initcall(pwm_init);