Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Generic pwmlib implementation
4 *
5 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
6 * Copyright (C) 2011-2012 Avionic Design GmbH
7 */
8
9#include <linux/acpi.h>
10#include <linux/module.h>
11#include <linux/idr.h>
12#include <linux/of.h>
13#include <linux/pwm.h>
14#include <linux/list.h>
15#include <linux/mutex.h>
16#include <linux/err.h>
17#include <linux/slab.h>
18#include <linux/device.h>
19#include <linux/debugfs.h>
20#include <linux/seq_file.h>
21
22#include <dt-bindings/pwm/pwm.h>
23
24#define CREATE_TRACE_POINTS
25#include <trace/events/pwm.h>
26
27/* protects access to pwm_chips */
28static DEFINE_MUTEX(pwm_lock);
29
30static DEFINE_IDR(pwm_chips);
31
32static void pwm_apply_debug(struct pwm_device *pwm,
33 const struct pwm_state *state)
34{
35 struct pwm_state *last = &pwm->last;
36 struct pwm_chip *chip = pwm->chip;
37 struct pwm_state s1 = { 0 }, s2 = { 0 };
38 int err;
39
40 if (!IS_ENABLED(CONFIG_PWM_DEBUG))
41 return;
42
43 /* No reasonable diagnosis possible without .get_state() */
44 if (!chip->ops->get_state)
45 return;
46
47 /*
48 * *state was just applied. Read out the hardware state and do some
49 * checks.
50 */
51
52 err = chip->ops->get_state(chip, pwm, &s1);
53 trace_pwm_get(pwm, &s1, err);
54 if (err)
55 /* If that failed there isn't much to debug */
56 return;
57
58 /*
59 * The lowlevel driver either ignored .polarity (which is a bug) or as
60 * best effort inverted .polarity and fixed .duty_cycle respectively.
61 * Undo this inversion and fixup for further tests.
62 */
63 if (s1.enabled && s1.polarity != state->polarity) {
64 s2.polarity = state->polarity;
65 s2.duty_cycle = s1.period - s1.duty_cycle;
66 s2.period = s1.period;
67 s2.enabled = s1.enabled;
68 } else {
69 s2 = s1;
70 }
71
72 if (s2.polarity != state->polarity &&
73 state->duty_cycle < state->period)
74 dev_warn(pwmchip_parent(chip), ".apply ignored .polarity\n");
75
76 if (state->enabled &&
77 last->polarity == state->polarity &&
78 last->period > s2.period &&
79 last->period <= state->period)
80 dev_warn(pwmchip_parent(chip),
81 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
82 state->period, s2.period, last->period);
83
84 if (state->enabled && state->period < s2.period)
85 dev_warn(pwmchip_parent(chip),
86 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
87 state->period, s2.period);
88
89 if (state->enabled &&
90 last->polarity == state->polarity &&
91 last->period == s2.period &&
92 last->duty_cycle > s2.duty_cycle &&
93 last->duty_cycle <= state->duty_cycle)
94 dev_warn(pwmchip_parent(chip),
95 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
96 state->duty_cycle, state->period,
97 s2.duty_cycle, s2.period,
98 last->duty_cycle, last->period);
99
100 if (state->enabled && state->duty_cycle < s2.duty_cycle)
101 dev_warn(pwmchip_parent(chip),
102 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
103 state->duty_cycle, state->period,
104 s2.duty_cycle, s2.period);
105
106 if (!state->enabled && s2.enabled && s2.duty_cycle > 0)
107 dev_warn(pwmchip_parent(chip),
108 "requested disabled, but yielded enabled with duty > 0\n");
109
110 /* reapply the state that the driver reported being configured. */
111 err = chip->ops->apply(chip, pwm, &s1);
112 trace_pwm_apply(pwm, &s1, err);
113 if (err) {
114 *last = s1;
115 dev_err(pwmchip_parent(chip), "failed to reapply current setting\n");
116 return;
117 }
118
119 *last = (struct pwm_state){ 0 };
120 err = chip->ops->get_state(chip, pwm, last);
121 trace_pwm_get(pwm, last, err);
122 if (err)
123 return;
124
125 /* reapplication of the current state should give an exact match */
126 if (s1.enabled != last->enabled ||
127 s1.polarity != last->polarity ||
128 (s1.enabled && s1.period != last->period) ||
129 (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
130 dev_err(pwmchip_parent(chip),
131 ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
132 s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
133 last->enabled, last->polarity, last->duty_cycle,
134 last->period);
135 }
136}
137
138/**
139 * __pwm_apply() - atomically apply a new state to a PWM device
140 * @pwm: PWM device
141 * @state: new state to apply
142 */
143static int __pwm_apply(struct pwm_device *pwm, const struct pwm_state *state)
144{
145 struct pwm_chip *chip;
146 int err;
147
148 if (!pwm || !state || !state->period ||
149 state->duty_cycle > state->period)
150 return -EINVAL;
151
152 chip = pwm->chip;
153
154 if (state->period == pwm->state.period &&
155 state->duty_cycle == pwm->state.duty_cycle &&
156 state->polarity == pwm->state.polarity &&
157 state->enabled == pwm->state.enabled &&
158 state->usage_power == pwm->state.usage_power)
159 return 0;
160
161 err = chip->ops->apply(chip, pwm, state);
162 trace_pwm_apply(pwm, state, err);
163 if (err)
164 return err;
165
166 pwm->state = *state;
167
168 /*
169 * only do this after pwm->state was applied as some
170 * implementations of .get_state depend on this
171 */
172 pwm_apply_debug(pwm, state);
173
174 return 0;
175}
176
177/**
178 * pwm_apply_might_sleep() - atomically apply a new state to a PWM device
179 * Cannot be used in atomic context.
180 * @pwm: PWM device
181 * @state: new state to apply
182 */
183int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state)
184{
185 int err;
186
187 /*
188 * Some lowlevel driver's implementations of .apply() make use of
189 * mutexes, also with some drivers only returning when the new
190 * configuration is active calling pwm_apply_might_sleep() from atomic context
191 * is a bad idea. So make it explicit that calling this function might
192 * sleep.
193 */
194 might_sleep();
195
196 if (IS_ENABLED(CONFIG_PWM_DEBUG) && pwm->chip->atomic) {
197 /*
198 * Catch any drivers that have been marked as atomic but
199 * that will sleep anyway.
200 */
201 non_block_start();
202 err = __pwm_apply(pwm, state);
203 non_block_end();
204 } else {
205 err = __pwm_apply(pwm, state);
206 }
207
208 return err;
209}
210EXPORT_SYMBOL_GPL(pwm_apply_might_sleep);
211
212/**
213 * pwm_apply_atomic() - apply a new state to a PWM device from atomic context
214 * Not all PWM devices support this function, check with pwm_might_sleep().
215 * @pwm: PWM device
216 * @state: new state to apply
217 */
218int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state)
219{
220 WARN_ONCE(!pwm->chip->atomic,
221 "sleeping PWM driver used in atomic context\n");
222
223 return __pwm_apply(pwm, state);
224}
225EXPORT_SYMBOL_GPL(pwm_apply_atomic);
226
227/**
228 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
229 * @pwm: PWM device
230 *
231 * This function will adjust the PWM config to the PWM arguments provided
232 * by the DT or PWM lookup table. This is particularly useful to adapt
233 * the bootloader config to the Linux one.
234 */
235int pwm_adjust_config(struct pwm_device *pwm)
236{
237 struct pwm_state state;
238 struct pwm_args pargs;
239
240 pwm_get_args(pwm, &pargs);
241 pwm_get_state(pwm, &state);
242
243 /*
244 * If the current period is zero it means that either the PWM driver
245 * does not support initial state retrieval or the PWM has not yet
246 * been configured.
247 *
248 * In either case, we setup the new period and polarity, and assign a
249 * duty cycle of 0.
250 */
251 if (!state.period) {
252 state.duty_cycle = 0;
253 state.period = pargs.period;
254 state.polarity = pargs.polarity;
255
256 return pwm_apply_might_sleep(pwm, &state);
257 }
258
259 /*
260 * Adjust the PWM duty cycle/period based on the period value provided
261 * in PWM args.
262 */
263 if (pargs.period != state.period) {
264 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
265
266 do_div(dutycycle, state.period);
267 state.duty_cycle = dutycycle;
268 state.period = pargs.period;
269 }
270
271 /*
272 * If the polarity changed, we should also change the duty cycle.
273 */
274 if (pargs.polarity != state.polarity) {
275 state.polarity = pargs.polarity;
276 state.duty_cycle = state.period - state.duty_cycle;
277 }
278
279 return pwm_apply_might_sleep(pwm, &state);
280}
281EXPORT_SYMBOL_GPL(pwm_adjust_config);
282
283/**
284 * pwm_capture() - capture and report a PWM signal
285 * @pwm: PWM device
286 * @result: structure to fill with capture result
287 * @timeout: time to wait, in milliseconds, before giving up on capture
288 *
289 * Returns: 0 on success or a negative error code on failure.
290 */
291int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
292 unsigned long timeout)
293{
294 int err;
295
296 if (!pwm || !pwm->chip->ops)
297 return -EINVAL;
298
299 if (!pwm->chip->ops->capture)
300 return -ENOSYS;
301
302 mutex_lock(&pwm_lock);
303 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
304 mutex_unlock(&pwm_lock);
305
306 return err;
307}
308EXPORT_SYMBOL_GPL(pwm_capture);
309
310static struct pwm_chip *pwmchip_find_by_name(const char *name)
311{
312 struct pwm_chip *chip;
313 unsigned long id, tmp;
314
315 if (!name)
316 return NULL;
317
318 mutex_lock(&pwm_lock);
319
320 idr_for_each_entry_ul(&pwm_chips, chip, tmp, id) {
321 const char *chip_name = dev_name(pwmchip_parent(chip));
322
323 if (chip_name && strcmp(chip_name, name) == 0) {
324 mutex_unlock(&pwm_lock);
325 return chip;
326 }
327 }
328
329 mutex_unlock(&pwm_lock);
330
331 return NULL;
332}
333
334static int pwm_device_request(struct pwm_device *pwm, const char *label)
335{
336 int err;
337 struct pwm_chip *chip = pwm->chip;
338 const struct pwm_ops *ops = chip->ops;
339
340 if (test_bit(PWMF_REQUESTED, &pwm->flags))
341 return -EBUSY;
342
343 if (!try_module_get(chip->owner))
344 return -ENODEV;
345
346 if (ops->request) {
347 err = ops->request(chip, pwm);
348 if (err) {
349 module_put(chip->owner);
350 return err;
351 }
352 }
353
354 if (ops->get_state) {
355 /*
356 * Zero-initialize state because most drivers are unaware of
357 * .usage_power. The other members of state are supposed to be
358 * set by lowlevel drivers. We still initialize the whole
359 * structure for simplicity even though this might paper over
360 * faulty implementations of .get_state().
361 */
362 struct pwm_state state = { 0, };
363
364 err = ops->get_state(chip, pwm, &state);
365 trace_pwm_get(pwm, &state, err);
366
367 if (!err)
368 pwm->state = state;
369
370 if (IS_ENABLED(CONFIG_PWM_DEBUG))
371 pwm->last = pwm->state;
372 }
373
374 set_bit(PWMF_REQUESTED, &pwm->flags);
375 pwm->label = label;
376
377 return 0;
378}
379
380/**
381 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
382 * @chip: PWM chip
383 * @index: per-chip index of the PWM to request
384 * @label: a literal description string of this PWM
385 *
386 * Returns: A pointer to the PWM device at the given index of the given PWM
387 * chip. A negative error code is returned if the index is not valid for the
388 * specified PWM chip or if the PWM device cannot be requested.
389 */
390struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
391 unsigned int index,
392 const char *label)
393{
394 struct pwm_device *pwm;
395 int err;
396
397 if (!chip || index >= chip->npwm)
398 return ERR_PTR(-EINVAL);
399
400 mutex_lock(&pwm_lock);
401 pwm = &chip->pwms[index];
402
403 err = pwm_device_request(pwm, label);
404 if (err < 0)
405 pwm = ERR_PTR(err);
406
407 mutex_unlock(&pwm_lock);
408 return pwm;
409}
410EXPORT_SYMBOL_GPL(pwm_request_from_chip);
411
412
413struct pwm_device *
414of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *args)
415{
416 struct pwm_device *pwm;
417
418 /* period in the second cell and flags in the third cell are optional */
419 if (args->args_count < 1)
420 return ERR_PTR(-EINVAL);
421
422 pwm = pwm_request_from_chip(chip, args->args[0], NULL);
423 if (IS_ERR(pwm))
424 return pwm;
425
426 if (args->args_count > 1)
427 pwm->args.period = args->args[1];
428
429 pwm->args.polarity = PWM_POLARITY_NORMAL;
430 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
431 pwm->args.polarity = PWM_POLARITY_INVERSED;
432
433 return pwm;
434}
435EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
436
437struct pwm_device *
438of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args)
439{
440 struct pwm_device *pwm;
441
442 pwm = pwm_request_from_chip(chip, 0, NULL);
443 if (IS_ERR(pwm))
444 return pwm;
445
446 if (args->args_count > 0)
447 pwm->args.period = args->args[0];
448
449 pwm->args.polarity = PWM_POLARITY_NORMAL;
450 if (args->args_count > 1 && args->args[1] & PWM_POLARITY_INVERTED)
451 pwm->args.polarity = PWM_POLARITY_INVERSED;
452
453 return pwm;
454}
455EXPORT_SYMBOL_GPL(of_pwm_single_xlate);
456
457#define PWMCHIP_ALIGN ARCH_DMA_MINALIGN
458
459static void *pwmchip_priv(struct pwm_chip *chip)
460{
461 return (void *)chip + ALIGN(sizeof(*chip), PWMCHIP_ALIGN);
462}
463
464/* This is the counterpart to pwmchip_alloc() */
465void pwmchip_put(struct pwm_chip *chip)
466{
467 kfree(chip);
468}
469EXPORT_SYMBOL_GPL(pwmchip_put);
470
471struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv)
472{
473 struct pwm_chip *chip;
474 size_t alloc_size;
475
476 alloc_size = size_add(ALIGN(sizeof(*chip), PWMCHIP_ALIGN), sizeof_priv);
477
478 chip = kzalloc(alloc_size, GFP_KERNEL);
479 if (!chip)
480 return ERR_PTR(-ENOMEM);
481
482 chip->dev = parent;
483 chip->npwm = npwm;
484
485 pwmchip_set_drvdata(chip, pwmchip_priv(chip));
486
487 return chip;
488}
489EXPORT_SYMBOL_GPL(pwmchip_alloc);
490
491static void devm_pwmchip_put(void *data)
492{
493 struct pwm_chip *chip = data;
494
495 pwmchip_put(chip);
496}
497
498struct pwm_chip *devm_pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv)
499{
500 struct pwm_chip *chip;
501 int ret;
502
503 chip = pwmchip_alloc(parent, npwm, sizeof_priv);
504 if (IS_ERR(chip))
505 return chip;
506
507 ret = devm_add_action_or_reset(parent, devm_pwmchip_put, chip);
508 if (ret)
509 return ERR_PTR(ret);
510
511 return chip;
512}
513EXPORT_SYMBOL_GPL(devm_pwmchip_alloc);
514
515static void of_pwmchip_add(struct pwm_chip *chip)
516{
517 if (!pwmchip_parent(chip) || !pwmchip_parent(chip)->of_node)
518 return;
519
520 if (!chip->of_xlate)
521 chip->of_xlate = of_pwm_xlate_with_flags;
522
523 of_node_get(pwmchip_parent(chip)->of_node);
524}
525
526static void of_pwmchip_remove(struct pwm_chip *chip)
527{
528 if (pwmchip_parent(chip))
529 of_node_put(pwmchip_parent(chip)->of_node);
530}
531
532static bool pwm_ops_check(const struct pwm_chip *chip)
533{
534 const struct pwm_ops *ops = chip->ops;
535
536 if (!ops->apply)
537 return false;
538
539 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
540 dev_warn(pwmchip_parent(chip),
541 "Please implement the .get_state() callback\n");
542
543 return true;
544}
545
546/**
547 * __pwmchip_add() - register a new PWM chip
548 * @chip: the PWM chip to add
549 * @owner: reference to the module providing the chip.
550 *
551 * Register a new PWM chip. @owner is supposed to be THIS_MODULE, use the
552 * pwmchip_add wrapper to do this right.
553 *
554 * Returns: 0 on success or a negative error code on failure.
555 */
556int __pwmchip_add(struct pwm_chip *chip, struct module *owner)
557{
558 unsigned int i;
559 int ret;
560
561 if (!chip || !pwmchip_parent(chip) || !chip->ops || !chip->npwm)
562 return -EINVAL;
563
564 if (!pwm_ops_check(chip))
565 return -EINVAL;
566
567 chip->owner = owner;
568
569 chip->pwms = kcalloc(chip->npwm, sizeof(*chip->pwms), GFP_KERNEL);
570 if (!chip->pwms)
571 return -ENOMEM;
572
573 mutex_lock(&pwm_lock);
574
575 ret = idr_alloc(&pwm_chips, chip, 0, 0, GFP_KERNEL);
576 if (ret < 0) {
577 mutex_unlock(&pwm_lock);
578 kfree(chip->pwms);
579 return ret;
580 }
581
582 chip->id = ret;
583
584 for (i = 0; i < chip->npwm; i++) {
585 struct pwm_device *pwm = &chip->pwms[i];
586
587 pwm->chip = chip;
588 pwm->hwpwm = i;
589 }
590
591 mutex_unlock(&pwm_lock);
592
593 if (IS_ENABLED(CONFIG_OF))
594 of_pwmchip_add(chip);
595
596 pwmchip_sysfs_export(chip);
597
598 return 0;
599}
600EXPORT_SYMBOL_GPL(__pwmchip_add);
601
602/**
603 * pwmchip_remove() - remove a PWM chip
604 * @chip: the PWM chip to remove
605 *
606 * Removes a PWM chip.
607 */
608void pwmchip_remove(struct pwm_chip *chip)
609{
610 pwmchip_sysfs_unexport(chip);
611
612 if (IS_ENABLED(CONFIG_OF))
613 of_pwmchip_remove(chip);
614
615 mutex_lock(&pwm_lock);
616
617 idr_remove(&pwm_chips, chip->id);
618
619 mutex_unlock(&pwm_lock);
620
621 kfree(chip->pwms);
622}
623EXPORT_SYMBOL_GPL(pwmchip_remove);
624
625static void devm_pwmchip_remove(void *data)
626{
627 struct pwm_chip *chip = data;
628
629 pwmchip_remove(chip);
630}
631
632int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner)
633{
634 int ret;
635
636 ret = __pwmchip_add(chip, owner);
637 if (ret)
638 return ret;
639
640 return devm_add_action_or_reset(dev, devm_pwmchip_remove, chip);
641}
642EXPORT_SYMBOL_GPL(__devm_pwmchip_add);
643
644static struct device_link *pwm_device_link_add(struct device *dev,
645 struct pwm_device *pwm)
646{
647 struct device_link *dl;
648
649 if (!dev) {
650 /*
651 * No device for the PWM consumer has been provided. It may
652 * impact the PM sequence ordering: the PWM supplier may get
653 * suspended before the consumer.
654 */
655 dev_warn(pwmchip_parent(pwm->chip),
656 "No consumer device specified to create a link to\n");
657 return NULL;
658 }
659
660 dl = device_link_add(dev, pwmchip_parent(pwm->chip), DL_FLAG_AUTOREMOVE_CONSUMER);
661 if (!dl) {
662 dev_err(dev, "failed to create device link to %s\n",
663 dev_name(pwmchip_parent(pwm->chip)));
664 return ERR_PTR(-EINVAL);
665 }
666
667 return dl;
668}
669
670static struct pwm_chip *fwnode_to_pwmchip(struct fwnode_handle *fwnode)
671{
672 struct pwm_chip *chip;
673 unsigned long id, tmp;
674
675 mutex_lock(&pwm_lock);
676
677 idr_for_each_entry_ul(&pwm_chips, chip, tmp, id)
678 if (pwmchip_parent(chip) && device_match_fwnode(pwmchip_parent(chip), fwnode)) {
679 mutex_unlock(&pwm_lock);
680 return chip;
681 }
682
683 mutex_unlock(&pwm_lock);
684
685 return ERR_PTR(-EPROBE_DEFER);
686}
687
688/**
689 * of_pwm_get() - request a PWM via the PWM framework
690 * @dev: device for PWM consumer
691 * @np: device node to get the PWM from
692 * @con_id: consumer name
693 *
694 * Returns the PWM device parsed from the phandle and index specified in the
695 * "pwms" property of a device tree node or a negative error-code on failure.
696 * Values parsed from the device tree are stored in the returned PWM device
697 * object.
698 *
699 * If con_id is NULL, the first PWM device listed in the "pwms" property will
700 * be requested. Otherwise the "pwm-names" property is used to do a reverse
701 * lookup of the PWM index. This also means that the "pwm-names" property
702 * becomes mandatory for devices that look up the PWM device via the con_id
703 * parameter.
704 *
705 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
706 * error code on failure.
707 */
708static struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
709 const char *con_id)
710{
711 struct pwm_device *pwm = NULL;
712 struct of_phandle_args args;
713 struct device_link *dl;
714 struct pwm_chip *chip;
715 int index = 0;
716 int err;
717
718 if (con_id) {
719 index = of_property_match_string(np, "pwm-names", con_id);
720 if (index < 0)
721 return ERR_PTR(index);
722 }
723
724 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
725 &args);
726 if (err) {
727 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
728 return ERR_PTR(err);
729 }
730
731 chip = fwnode_to_pwmchip(of_fwnode_handle(args.np));
732 if (IS_ERR(chip)) {
733 if (PTR_ERR(chip) != -EPROBE_DEFER)
734 pr_err("%s(): PWM chip not found\n", __func__);
735
736 pwm = ERR_CAST(chip);
737 goto put;
738 }
739
740 pwm = chip->of_xlate(chip, &args);
741 if (IS_ERR(pwm))
742 goto put;
743
744 dl = pwm_device_link_add(dev, pwm);
745 if (IS_ERR(dl)) {
746 /* of_xlate ended up calling pwm_request_from_chip() */
747 pwm_put(pwm);
748 pwm = ERR_CAST(dl);
749 goto put;
750 }
751
752 /*
753 * If a consumer name was not given, try to look it up from the
754 * "pwm-names" property if it exists. Otherwise use the name of
755 * the user device node.
756 */
757 if (!con_id) {
758 err = of_property_read_string_index(np, "pwm-names", index,
759 &con_id);
760 if (err < 0)
761 con_id = np->name;
762 }
763
764 pwm->label = con_id;
765
766put:
767 of_node_put(args.np);
768
769 return pwm;
770}
771
772/**
773 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
774 * @fwnode: firmware node to get the "pwms" property from
775 *
776 * Returns the PWM device parsed from the fwnode and index specified in the
777 * "pwms" property or a negative error-code on failure.
778 * Values parsed from the device tree are stored in the returned PWM device
779 * object.
780 *
781 * This is analogous to of_pwm_get() except con_id is not yet supported.
782 * ACPI entries must look like
783 * Package () {"pwms", Package ()
784 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
785 *
786 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
787 * error code on failure.
788 */
789static struct pwm_device *acpi_pwm_get(const struct fwnode_handle *fwnode)
790{
791 struct pwm_device *pwm;
792 struct fwnode_reference_args args;
793 struct pwm_chip *chip;
794 int ret;
795
796 memset(&args, 0, sizeof(args));
797
798 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
799 if (ret < 0)
800 return ERR_PTR(ret);
801
802 if (args.nargs < 2)
803 return ERR_PTR(-EPROTO);
804
805 chip = fwnode_to_pwmchip(args.fwnode);
806 if (IS_ERR(chip))
807 return ERR_CAST(chip);
808
809 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
810 if (IS_ERR(pwm))
811 return pwm;
812
813 pwm->args.period = args.args[1];
814 pwm->args.polarity = PWM_POLARITY_NORMAL;
815
816 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
817 pwm->args.polarity = PWM_POLARITY_INVERSED;
818
819 return pwm;
820}
821
822static DEFINE_MUTEX(pwm_lookup_lock);
823static LIST_HEAD(pwm_lookup_list);
824
825/**
826 * pwm_add_table() - register PWM device consumers
827 * @table: array of consumers to register
828 * @num: number of consumers in table
829 */
830void pwm_add_table(struct pwm_lookup *table, size_t num)
831{
832 mutex_lock(&pwm_lookup_lock);
833
834 while (num--) {
835 list_add_tail(&table->list, &pwm_lookup_list);
836 table++;
837 }
838
839 mutex_unlock(&pwm_lookup_lock);
840}
841
842/**
843 * pwm_remove_table() - unregister PWM device consumers
844 * @table: array of consumers to unregister
845 * @num: number of consumers in table
846 */
847void pwm_remove_table(struct pwm_lookup *table, size_t num)
848{
849 mutex_lock(&pwm_lookup_lock);
850
851 while (num--) {
852 list_del(&table->list);
853 table++;
854 }
855
856 mutex_unlock(&pwm_lookup_lock);
857}
858
859/**
860 * pwm_get() - look up and request a PWM device
861 * @dev: device for PWM consumer
862 * @con_id: consumer name
863 *
864 * Lookup is first attempted using DT. If the device was not instantiated from
865 * a device tree, a PWM chip and a relative index is looked up via a table
866 * supplied by board setup code (see pwm_add_table()).
867 *
868 * Once a PWM chip has been found the specified PWM device will be requested
869 * and is ready to be used.
870 *
871 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
872 * error code on failure.
873 */
874struct pwm_device *pwm_get(struct device *dev, const char *con_id)
875{
876 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
877 const char *dev_id = dev ? dev_name(dev) : NULL;
878 struct pwm_device *pwm;
879 struct pwm_chip *chip;
880 struct device_link *dl;
881 unsigned int best = 0;
882 struct pwm_lookup *p, *chosen = NULL;
883 unsigned int match;
884 int err;
885
886 /* look up via DT first */
887 if (is_of_node(fwnode))
888 return of_pwm_get(dev, to_of_node(fwnode), con_id);
889
890 /* then lookup via ACPI */
891 if (is_acpi_node(fwnode)) {
892 pwm = acpi_pwm_get(fwnode);
893 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
894 return pwm;
895 }
896
897 /*
898 * We look up the provider in the static table typically provided by
899 * board setup code. We first try to lookup the consumer device by
900 * name. If the consumer device was passed in as NULL or if no match
901 * was found, we try to find the consumer by directly looking it up
902 * by name.
903 *
904 * If a match is found, the provider PWM chip is looked up by name
905 * and a PWM device is requested using the PWM device per-chip index.
906 *
907 * The lookup algorithm was shamelessly taken from the clock
908 * framework:
909 *
910 * We do slightly fuzzy matching here:
911 * An entry with a NULL ID is assumed to be a wildcard.
912 * If an entry has a device ID, it must match
913 * If an entry has a connection ID, it must match
914 * Then we take the most specific entry - with the following order
915 * of precedence: dev+con > dev only > con only.
916 */
917 mutex_lock(&pwm_lookup_lock);
918
919 list_for_each_entry(p, &pwm_lookup_list, list) {
920 match = 0;
921
922 if (p->dev_id) {
923 if (!dev_id || strcmp(p->dev_id, dev_id))
924 continue;
925
926 match += 2;
927 }
928
929 if (p->con_id) {
930 if (!con_id || strcmp(p->con_id, con_id))
931 continue;
932
933 match += 1;
934 }
935
936 if (match > best) {
937 chosen = p;
938
939 if (match != 3)
940 best = match;
941 else
942 break;
943 }
944 }
945
946 mutex_unlock(&pwm_lookup_lock);
947
948 if (!chosen)
949 return ERR_PTR(-ENODEV);
950
951 chip = pwmchip_find_by_name(chosen->provider);
952
953 /*
954 * If the lookup entry specifies a module, load the module and retry
955 * the PWM chip lookup. This can be used to work around driver load
956 * ordering issues if driver's can't be made to properly support the
957 * deferred probe mechanism.
958 */
959 if (!chip && chosen->module) {
960 err = request_module(chosen->module);
961 if (err == 0)
962 chip = pwmchip_find_by_name(chosen->provider);
963 }
964
965 if (!chip)
966 return ERR_PTR(-EPROBE_DEFER);
967
968 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
969 if (IS_ERR(pwm))
970 return pwm;
971
972 dl = pwm_device_link_add(dev, pwm);
973 if (IS_ERR(dl)) {
974 pwm_put(pwm);
975 return ERR_CAST(dl);
976 }
977
978 pwm->args.period = chosen->period;
979 pwm->args.polarity = chosen->polarity;
980
981 return pwm;
982}
983EXPORT_SYMBOL_GPL(pwm_get);
984
985/**
986 * pwm_put() - release a PWM device
987 * @pwm: PWM device
988 */
989void pwm_put(struct pwm_device *pwm)
990{
991 if (!pwm)
992 return;
993
994 mutex_lock(&pwm_lock);
995
996 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
997 pr_warn("PWM device already freed\n");
998 goto out;
999 }
1000
1001 if (pwm->chip->ops->free)
1002 pwm->chip->ops->free(pwm->chip, pwm);
1003
1004 pwm->label = NULL;
1005
1006 module_put(pwm->chip->owner);
1007out:
1008 mutex_unlock(&pwm_lock);
1009}
1010EXPORT_SYMBOL_GPL(pwm_put);
1011
1012static void devm_pwm_release(void *pwm)
1013{
1014 pwm_put(pwm);
1015}
1016
1017/**
1018 * devm_pwm_get() - resource managed pwm_get()
1019 * @dev: device for PWM consumer
1020 * @con_id: consumer name
1021 *
1022 * This function performs like pwm_get() but the acquired PWM device will
1023 * automatically be released on driver detach.
1024 *
1025 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1026 * error code on failure.
1027 */
1028struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
1029{
1030 struct pwm_device *pwm;
1031 int ret;
1032
1033 pwm = pwm_get(dev, con_id);
1034 if (IS_ERR(pwm))
1035 return pwm;
1036
1037 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
1038 if (ret)
1039 return ERR_PTR(ret);
1040
1041 return pwm;
1042}
1043EXPORT_SYMBOL_GPL(devm_pwm_get);
1044
1045/**
1046 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
1047 * @dev: device for PWM consumer
1048 * @fwnode: firmware node to get the PWM from
1049 * @con_id: consumer name
1050 *
1051 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
1052 * acpi_pwm_get() for a detailed description.
1053 *
1054 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1055 * error code on failure.
1056 */
1057struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
1058 struct fwnode_handle *fwnode,
1059 const char *con_id)
1060{
1061 struct pwm_device *pwm = ERR_PTR(-ENODEV);
1062 int ret;
1063
1064 if (is_of_node(fwnode))
1065 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1066 else if (is_acpi_node(fwnode))
1067 pwm = acpi_pwm_get(fwnode);
1068 if (IS_ERR(pwm))
1069 return pwm;
1070
1071 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
1072 if (ret)
1073 return ERR_PTR(ret);
1074
1075 return pwm;
1076}
1077EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1078
1079#ifdef CONFIG_DEBUG_FS
1080static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1081{
1082 unsigned int i;
1083
1084 for (i = 0; i < chip->npwm; i++) {
1085 struct pwm_device *pwm = &chip->pwms[i];
1086 struct pwm_state state;
1087
1088 pwm_get_state(pwm, &state);
1089
1090 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1091
1092 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1093 seq_puts(s, " requested");
1094
1095 if (state.enabled)
1096 seq_puts(s, " enabled");
1097
1098 seq_printf(s, " period: %llu ns", state.period);
1099 seq_printf(s, " duty: %llu ns", state.duty_cycle);
1100 seq_printf(s, " polarity: %s",
1101 state.polarity ? "inverse" : "normal");
1102
1103 if (state.usage_power)
1104 seq_puts(s, " usage_power");
1105
1106 seq_puts(s, "\n");
1107 }
1108}
1109
1110static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1111{
1112 unsigned long id = *pos;
1113 void *ret;
1114
1115 mutex_lock(&pwm_lock);
1116 s->private = "";
1117
1118 ret = idr_get_next_ul(&pwm_chips, &id);
1119 *pos = id;
1120 return ret;
1121}
1122
1123static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1124{
1125 unsigned long id = *pos + 1;
1126 void *ret;
1127
1128 s->private = "\n";
1129
1130 ret = idr_get_next_ul(&pwm_chips, &id);
1131 *pos = id;
1132 return ret;
1133}
1134
1135static void pwm_seq_stop(struct seq_file *s, void *v)
1136{
1137 mutex_unlock(&pwm_lock);
1138}
1139
1140static int pwm_seq_show(struct seq_file *s, void *v)
1141{
1142 struct pwm_chip *chip = v;
1143
1144 seq_printf(s, "%s%d: %s/%s, %d PWM device%s\n",
1145 (char *)s->private, chip->id,
1146 pwmchip_parent(chip)->bus ? pwmchip_parent(chip)->bus->name : "no-bus",
1147 dev_name(pwmchip_parent(chip)), chip->npwm,
1148 (chip->npwm != 1) ? "s" : "");
1149
1150 pwm_dbg_show(chip, s);
1151
1152 return 0;
1153}
1154
1155static const struct seq_operations pwm_debugfs_sops = {
1156 .start = pwm_seq_start,
1157 .next = pwm_seq_next,
1158 .stop = pwm_seq_stop,
1159 .show = pwm_seq_show,
1160};
1161
1162DEFINE_SEQ_ATTRIBUTE(pwm_debugfs);
1163
1164static int __init pwm_debugfs_init(void)
1165{
1166 debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops);
1167
1168 return 0;
1169}
1170subsys_initcall(pwm_debugfs_init);
1171#endif /* CONFIG_DEBUG_FS */
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Generic pwmlib implementation
4 *
5 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
6 * Copyright (C) 2011-2012 Avionic Design GmbH
7 */
8
9#include <linux/acpi.h>
10#include <linux/module.h>
11#include <linux/pwm.h>
12#include <linux/radix-tree.h>
13#include <linux/list.h>
14#include <linux/mutex.h>
15#include <linux/err.h>
16#include <linux/slab.h>
17#include <linux/device.h>
18#include <linux/debugfs.h>
19#include <linux/seq_file.h>
20
21#include <dt-bindings/pwm/pwm.h>
22
23#define CREATE_TRACE_POINTS
24#include <trace/events/pwm.h>
25
26#define MAX_PWMS 1024
27
28static DEFINE_MUTEX(pwm_lookup_lock);
29static LIST_HEAD(pwm_lookup_list);
30static DEFINE_MUTEX(pwm_lock);
31static LIST_HEAD(pwm_chips);
32static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
33static RADIX_TREE(pwm_tree, GFP_KERNEL);
34
35static struct pwm_device *pwm_to_device(unsigned int pwm)
36{
37 return radix_tree_lookup(&pwm_tree, pwm);
38}
39
40static int alloc_pwms(unsigned int count)
41{
42 unsigned int start;
43
44 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, 0,
45 count, 0);
46
47 if (start + count > MAX_PWMS)
48 return -ENOSPC;
49
50 return start;
51}
52
53static void free_pwms(struct pwm_chip *chip)
54{
55 unsigned int i;
56
57 for (i = 0; i < chip->npwm; i++) {
58 struct pwm_device *pwm = &chip->pwms[i];
59
60 radix_tree_delete(&pwm_tree, pwm->pwm);
61 }
62
63 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
64
65 kfree(chip->pwms);
66 chip->pwms = NULL;
67}
68
69static struct pwm_chip *pwmchip_find_by_name(const char *name)
70{
71 struct pwm_chip *chip;
72
73 if (!name)
74 return NULL;
75
76 mutex_lock(&pwm_lock);
77
78 list_for_each_entry(chip, &pwm_chips, list) {
79 const char *chip_name = dev_name(chip->dev);
80
81 if (chip_name && strcmp(chip_name, name) == 0) {
82 mutex_unlock(&pwm_lock);
83 return chip;
84 }
85 }
86
87 mutex_unlock(&pwm_lock);
88
89 return NULL;
90}
91
92static int pwm_device_request(struct pwm_device *pwm, const char *label)
93{
94 int err;
95
96 if (test_bit(PWMF_REQUESTED, &pwm->flags))
97 return -EBUSY;
98
99 if (!try_module_get(pwm->chip->ops->owner))
100 return -ENODEV;
101
102 if (pwm->chip->ops->request) {
103 err = pwm->chip->ops->request(pwm->chip, pwm);
104 if (err) {
105 module_put(pwm->chip->ops->owner);
106 return err;
107 }
108 }
109
110 if (pwm->chip->ops->get_state) {
111 pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state);
112 trace_pwm_get(pwm, &pwm->state);
113
114 if (IS_ENABLED(CONFIG_PWM_DEBUG))
115 pwm->last = pwm->state;
116 }
117
118 set_bit(PWMF_REQUESTED, &pwm->flags);
119 pwm->label = label;
120
121 return 0;
122}
123
124struct pwm_device *
125of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
126{
127 struct pwm_device *pwm;
128
129 if (pc->of_pwm_n_cells < 2)
130 return ERR_PTR(-EINVAL);
131
132 /* flags in the third cell are optional */
133 if (args->args_count < 2)
134 return ERR_PTR(-EINVAL);
135
136 if (args->args[0] >= pc->npwm)
137 return ERR_PTR(-EINVAL);
138
139 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
140 if (IS_ERR(pwm))
141 return pwm;
142
143 pwm->args.period = args->args[1];
144 pwm->args.polarity = PWM_POLARITY_NORMAL;
145
146 if (pc->of_pwm_n_cells >= 3) {
147 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
148 pwm->args.polarity = PWM_POLARITY_INVERSED;
149 }
150
151 return pwm;
152}
153EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
154
155static void of_pwmchip_add(struct pwm_chip *chip)
156{
157 if (!chip->dev || !chip->dev->of_node)
158 return;
159
160 if (!chip->of_xlate) {
161 u32 pwm_cells;
162
163 if (of_property_read_u32(chip->dev->of_node, "#pwm-cells",
164 &pwm_cells))
165 pwm_cells = 2;
166
167 chip->of_xlate = of_pwm_xlate_with_flags;
168 chip->of_pwm_n_cells = pwm_cells;
169 }
170
171 of_node_get(chip->dev->of_node);
172}
173
174static void of_pwmchip_remove(struct pwm_chip *chip)
175{
176 if (chip->dev)
177 of_node_put(chip->dev->of_node);
178}
179
180/**
181 * pwm_set_chip_data() - set private chip data for a PWM
182 * @pwm: PWM device
183 * @data: pointer to chip-specific data
184 *
185 * Returns: 0 on success or a negative error code on failure.
186 */
187int pwm_set_chip_data(struct pwm_device *pwm, void *data)
188{
189 if (!pwm)
190 return -EINVAL;
191
192 pwm->chip_data = data;
193
194 return 0;
195}
196EXPORT_SYMBOL_GPL(pwm_set_chip_data);
197
198/**
199 * pwm_get_chip_data() - get private chip data for a PWM
200 * @pwm: PWM device
201 *
202 * Returns: A pointer to the chip-private data for the PWM device.
203 */
204void *pwm_get_chip_data(struct pwm_device *pwm)
205{
206 return pwm ? pwm->chip_data : NULL;
207}
208EXPORT_SYMBOL_GPL(pwm_get_chip_data);
209
210static bool pwm_ops_check(const struct pwm_chip *chip)
211{
212
213 const struct pwm_ops *ops = chip->ops;
214
215 /* driver supports legacy, non-atomic operation */
216 if (ops->config && ops->enable && ops->disable) {
217 if (IS_ENABLED(CONFIG_PWM_DEBUG))
218 dev_warn(chip->dev,
219 "Driver needs updating to atomic API\n");
220
221 return true;
222 }
223
224 if (!ops->apply)
225 return false;
226
227 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
228 dev_warn(chip->dev,
229 "Please implement the .get_state() callback\n");
230
231 return true;
232}
233
234/**
235 * pwmchip_add() - register a new PWM chip
236 * @chip: the PWM chip to add
237 *
238 * Register a new PWM chip.
239 *
240 * Returns: 0 on success or a negative error code on failure.
241 */
242int pwmchip_add(struct pwm_chip *chip)
243{
244 struct pwm_device *pwm;
245 unsigned int i;
246 int ret;
247
248 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
249 return -EINVAL;
250
251 if (!pwm_ops_check(chip))
252 return -EINVAL;
253
254 mutex_lock(&pwm_lock);
255
256 ret = alloc_pwms(chip->npwm);
257 if (ret < 0)
258 goto out;
259
260 chip->base = ret;
261
262 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
263 if (!chip->pwms) {
264 ret = -ENOMEM;
265 goto out;
266 }
267
268 for (i = 0; i < chip->npwm; i++) {
269 pwm = &chip->pwms[i];
270
271 pwm->chip = chip;
272 pwm->pwm = chip->base + i;
273 pwm->hwpwm = i;
274
275 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
276 }
277
278 bitmap_set(allocated_pwms, chip->base, chip->npwm);
279
280 INIT_LIST_HEAD(&chip->list);
281 list_add(&chip->list, &pwm_chips);
282
283 ret = 0;
284
285 if (IS_ENABLED(CONFIG_OF))
286 of_pwmchip_add(chip);
287
288out:
289 mutex_unlock(&pwm_lock);
290
291 if (!ret)
292 pwmchip_sysfs_export(chip);
293
294 return ret;
295}
296EXPORT_SYMBOL_GPL(pwmchip_add);
297
298/**
299 * pwmchip_remove() - remove a PWM chip
300 * @chip: the PWM chip to remove
301 *
302 * Removes a PWM chip. This function may return busy if the PWM chip provides
303 * a PWM device that is still requested.
304 *
305 * Returns: 0 on success or a negative error code on failure.
306 */
307int pwmchip_remove(struct pwm_chip *chip)
308{
309 pwmchip_sysfs_unexport(chip);
310
311 mutex_lock(&pwm_lock);
312
313 list_del_init(&chip->list);
314
315 if (IS_ENABLED(CONFIG_OF))
316 of_pwmchip_remove(chip);
317
318 free_pwms(chip);
319
320 mutex_unlock(&pwm_lock);
321
322 return 0;
323}
324EXPORT_SYMBOL_GPL(pwmchip_remove);
325
326static void devm_pwmchip_remove(void *data)
327{
328 struct pwm_chip *chip = data;
329
330 pwmchip_remove(chip);
331}
332
333int devm_pwmchip_add(struct device *dev, struct pwm_chip *chip)
334{
335 int ret;
336
337 ret = pwmchip_add(chip);
338 if (ret)
339 return ret;
340
341 return devm_add_action_or_reset(dev, devm_pwmchip_remove, chip);
342}
343EXPORT_SYMBOL_GPL(devm_pwmchip_add);
344
345/**
346 * pwm_request() - request a PWM device
347 * @pwm: global PWM device index
348 * @label: PWM device label
349 *
350 * This function is deprecated, use pwm_get() instead.
351 *
352 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
353 * failure.
354 */
355struct pwm_device *pwm_request(int pwm, const char *label)
356{
357 struct pwm_device *dev;
358 int err;
359
360 if (pwm < 0 || pwm >= MAX_PWMS)
361 return ERR_PTR(-EINVAL);
362
363 mutex_lock(&pwm_lock);
364
365 dev = pwm_to_device(pwm);
366 if (!dev) {
367 dev = ERR_PTR(-EPROBE_DEFER);
368 goto out;
369 }
370
371 err = pwm_device_request(dev, label);
372 if (err < 0)
373 dev = ERR_PTR(err);
374
375out:
376 mutex_unlock(&pwm_lock);
377
378 return dev;
379}
380EXPORT_SYMBOL_GPL(pwm_request);
381
382/**
383 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
384 * @chip: PWM chip
385 * @index: per-chip index of the PWM to request
386 * @label: a literal description string of this PWM
387 *
388 * Returns: A pointer to the PWM device at the given index of the given PWM
389 * chip. A negative error code is returned if the index is not valid for the
390 * specified PWM chip or if the PWM device cannot be requested.
391 */
392struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
393 unsigned int index,
394 const char *label)
395{
396 struct pwm_device *pwm;
397 int err;
398
399 if (!chip || index >= chip->npwm)
400 return ERR_PTR(-EINVAL);
401
402 mutex_lock(&pwm_lock);
403 pwm = &chip->pwms[index];
404
405 err = pwm_device_request(pwm, label);
406 if (err < 0)
407 pwm = ERR_PTR(err);
408
409 mutex_unlock(&pwm_lock);
410 return pwm;
411}
412EXPORT_SYMBOL_GPL(pwm_request_from_chip);
413
414/**
415 * pwm_free() - free a PWM device
416 * @pwm: PWM device
417 *
418 * This function is deprecated, use pwm_put() instead.
419 */
420void pwm_free(struct pwm_device *pwm)
421{
422 pwm_put(pwm);
423}
424EXPORT_SYMBOL_GPL(pwm_free);
425
426static void pwm_apply_state_debug(struct pwm_device *pwm,
427 const struct pwm_state *state)
428{
429 struct pwm_state *last = &pwm->last;
430 struct pwm_chip *chip = pwm->chip;
431 struct pwm_state s1, s2;
432 int err;
433
434 if (!IS_ENABLED(CONFIG_PWM_DEBUG))
435 return;
436
437 /* No reasonable diagnosis possible without .get_state() */
438 if (!chip->ops->get_state)
439 return;
440
441 /*
442 * *state was just applied. Read out the hardware state and do some
443 * checks.
444 */
445
446 chip->ops->get_state(chip, pwm, &s1);
447 trace_pwm_get(pwm, &s1);
448
449 /*
450 * The lowlevel driver either ignored .polarity (which is a bug) or as
451 * best effort inverted .polarity and fixed .duty_cycle respectively.
452 * Undo this inversion and fixup for further tests.
453 */
454 if (s1.enabled && s1.polarity != state->polarity) {
455 s2.polarity = state->polarity;
456 s2.duty_cycle = s1.period - s1.duty_cycle;
457 s2.period = s1.period;
458 s2.enabled = s1.enabled;
459 } else {
460 s2 = s1;
461 }
462
463 if (s2.polarity != state->polarity &&
464 state->duty_cycle < state->period)
465 dev_warn(chip->dev, ".apply ignored .polarity\n");
466
467 if (state->enabled &&
468 last->polarity == state->polarity &&
469 last->period > s2.period &&
470 last->period <= state->period)
471 dev_warn(chip->dev,
472 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
473 state->period, s2.period, last->period);
474
475 if (state->enabled && state->period < s2.period)
476 dev_warn(chip->dev,
477 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
478 state->period, s2.period);
479
480 if (state->enabled &&
481 last->polarity == state->polarity &&
482 last->period == s2.period &&
483 last->duty_cycle > s2.duty_cycle &&
484 last->duty_cycle <= state->duty_cycle)
485 dev_warn(chip->dev,
486 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
487 state->duty_cycle, state->period,
488 s2.duty_cycle, s2.period,
489 last->duty_cycle, last->period);
490
491 if (state->enabled && state->duty_cycle < s2.duty_cycle)
492 dev_warn(chip->dev,
493 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
494 state->duty_cycle, state->period,
495 s2.duty_cycle, s2.period);
496
497 if (!state->enabled && s2.enabled && s2.duty_cycle > 0)
498 dev_warn(chip->dev,
499 "requested disabled, but yielded enabled with duty > 0\n");
500
501 /* reapply the state that the driver reported being configured. */
502 err = chip->ops->apply(chip, pwm, &s1);
503 if (err) {
504 *last = s1;
505 dev_err(chip->dev, "failed to reapply current setting\n");
506 return;
507 }
508
509 trace_pwm_apply(pwm, &s1);
510
511 chip->ops->get_state(chip, pwm, last);
512 trace_pwm_get(pwm, last);
513
514 /* reapplication of the current state should give an exact match */
515 if (s1.enabled != last->enabled ||
516 s1.polarity != last->polarity ||
517 (s1.enabled && s1.period != last->period) ||
518 (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
519 dev_err(chip->dev,
520 ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
521 s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
522 last->enabled, last->polarity, last->duty_cycle,
523 last->period);
524 }
525}
526
527/**
528 * pwm_apply_state() - atomically apply a new state to a PWM device
529 * @pwm: PWM device
530 * @state: new state to apply
531 */
532int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
533{
534 struct pwm_chip *chip;
535 int err;
536
537 if (!pwm || !state || !state->period ||
538 state->duty_cycle > state->period)
539 return -EINVAL;
540
541 chip = pwm->chip;
542
543 if (state->period == pwm->state.period &&
544 state->duty_cycle == pwm->state.duty_cycle &&
545 state->polarity == pwm->state.polarity &&
546 state->enabled == pwm->state.enabled &&
547 state->usage_power == pwm->state.usage_power)
548 return 0;
549
550 if (chip->ops->apply) {
551 err = chip->ops->apply(chip, pwm, state);
552 if (err)
553 return err;
554
555 trace_pwm_apply(pwm, state);
556
557 pwm->state = *state;
558
559 /*
560 * only do this after pwm->state was applied as some
561 * implementations of .get_state depend on this
562 */
563 pwm_apply_state_debug(pwm, state);
564 } else {
565 /*
566 * FIXME: restore the initial state in case of error.
567 */
568 if (state->polarity != pwm->state.polarity) {
569 if (!chip->ops->set_polarity)
570 return -EINVAL;
571
572 /*
573 * Changing the polarity of a running PWM is
574 * only allowed when the PWM driver implements
575 * ->apply().
576 */
577 if (pwm->state.enabled) {
578 chip->ops->disable(chip, pwm);
579 pwm->state.enabled = false;
580 }
581
582 err = chip->ops->set_polarity(chip, pwm,
583 state->polarity);
584 if (err)
585 return err;
586
587 pwm->state.polarity = state->polarity;
588 }
589
590 if (state->period != pwm->state.period ||
591 state->duty_cycle != pwm->state.duty_cycle) {
592 err = chip->ops->config(pwm->chip, pwm,
593 state->duty_cycle,
594 state->period);
595 if (err)
596 return err;
597
598 pwm->state.duty_cycle = state->duty_cycle;
599 pwm->state.period = state->period;
600 }
601
602 if (state->enabled != pwm->state.enabled) {
603 if (state->enabled) {
604 err = chip->ops->enable(chip, pwm);
605 if (err)
606 return err;
607 } else {
608 chip->ops->disable(chip, pwm);
609 }
610
611 pwm->state.enabled = state->enabled;
612 }
613 }
614
615 return 0;
616}
617EXPORT_SYMBOL_GPL(pwm_apply_state);
618
619/**
620 * pwm_capture() - capture and report a PWM signal
621 * @pwm: PWM device
622 * @result: structure to fill with capture result
623 * @timeout: time to wait, in milliseconds, before giving up on capture
624 *
625 * Returns: 0 on success or a negative error code on failure.
626 */
627int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
628 unsigned long timeout)
629{
630 int err;
631
632 if (!pwm || !pwm->chip->ops)
633 return -EINVAL;
634
635 if (!pwm->chip->ops->capture)
636 return -ENOSYS;
637
638 mutex_lock(&pwm_lock);
639 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
640 mutex_unlock(&pwm_lock);
641
642 return err;
643}
644EXPORT_SYMBOL_GPL(pwm_capture);
645
646/**
647 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
648 * @pwm: PWM device
649 *
650 * This function will adjust the PWM config to the PWM arguments provided
651 * by the DT or PWM lookup table. This is particularly useful to adapt
652 * the bootloader config to the Linux one.
653 */
654int pwm_adjust_config(struct pwm_device *pwm)
655{
656 struct pwm_state state;
657 struct pwm_args pargs;
658
659 pwm_get_args(pwm, &pargs);
660 pwm_get_state(pwm, &state);
661
662 /*
663 * If the current period is zero it means that either the PWM driver
664 * does not support initial state retrieval or the PWM has not yet
665 * been configured.
666 *
667 * In either case, we setup the new period and polarity, and assign a
668 * duty cycle of 0.
669 */
670 if (!state.period) {
671 state.duty_cycle = 0;
672 state.period = pargs.period;
673 state.polarity = pargs.polarity;
674
675 return pwm_apply_state(pwm, &state);
676 }
677
678 /*
679 * Adjust the PWM duty cycle/period based on the period value provided
680 * in PWM args.
681 */
682 if (pargs.period != state.period) {
683 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
684
685 do_div(dutycycle, state.period);
686 state.duty_cycle = dutycycle;
687 state.period = pargs.period;
688 }
689
690 /*
691 * If the polarity changed, we should also change the duty cycle.
692 */
693 if (pargs.polarity != state.polarity) {
694 state.polarity = pargs.polarity;
695 state.duty_cycle = state.period - state.duty_cycle;
696 }
697
698 return pwm_apply_state(pwm, &state);
699}
700EXPORT_SYMBOL_GPL(pwm_adjust_config);
701
702static struct pwm_chip *fwnode_to_pwmchip(struct fwnode_handle *fwnode)
703{
704 struct pwm_chip *chip;
705
706 mutex_lock(&pwm_lock);
707
708 list_for_each_entry(chip, &pwm_chips, list)
709 if (chip->dev && dev_fwnode(chip->dev) == fwnode) {
710 mutex_unlock(&pwm_lock);
711 return chip;
712 }
713
714 mutex_unlock(&pwm_lock);
715
716 return ERR_PTR(-EPROBE_DEFER);
717}
718
719static struct device_link *pwm_device_link_add(struct device *dev,
720 struct pwm_device *pwm)
721{
722 struct device_link *dl;
723
724 if (!dev) {
725 /*
726 * No device for the PWM consumer has been provided. It may
727 * impact the PM sequence ordering: the PWM supplier may get
728 * suspended before the consumer.
729 */
730 dev_warn(pwm->chip->dev,
731 "No consumer device specified to create a link to\n");
732 return NULL;
733 }
734
735 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
736 if (!dl) {
737 dev_err(dev, "failed to create device link to %s\n",
738 dev_name(pwm->chip->dev));
739 return ERR_PTR(-EINVAL);
740 }
741
742 return dl;
743}
744
745/**
746 * of_pwm_get() - request a PWM via the PWM framework
747 * @dev: device for PWM consumer
748 * @np: device node to get the PWM from
749 * @con_id: consumer name
750 *
751 * Returns the PWM device parsed from the phandle and index specified in the
752 * "pwms" property of a device tree node or a negative error-code on failure.
753 * Values parsed from the device tree are stored in the returned PWM device
754 * object.
755 *
756 * If con_id is NULL, the first PWM device listed in the "pwms" property will
757 * be requested. Otherwise the "pwm-names" property is used to do a reverse
758 * lookup of the PWM index. This also means that the "pwm-names" property
759 * becomes mandatory for devices that look up the PWM device via the con_id
760 * parameter.
761 *
762 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
763 * error code on failure.
764 */
765struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
766 const char *con_id)
767{
768 struct pwm_device *pwm = NULL;
769 struct of_phandle_args args;
770 struct device_link *dl;
771 struct pwm_chip *pc;
772 int index = 0;
773 int err;
774
775 if (con_id) {
776 index = of_property_match_string(np, "pwm-names", con_id);
777 if (index < 0)
778 return ERR_PTR(index);
779 }
780
781 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
782 &args);
783 if (err) {
784 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
785 return ERR_PTR(err);
786 }
787
788 pc = fwnode_to_pwmchip(of_fwnode_handle(args.np));
789 if (IS_ERR(pc)) {
790 if (PTR_ERR(pc) != -EPROBE_DEFER)
791 pr_err("%s(): PWM chip not found\n", __func__);
792
793 pwm = ERR_CAST(pc);
794 goto put;
795 }
796
797 pwm = pc->of_xlate(pc, &args);
798 if (IS_ERR(pwm))
799 goto put;
800
801 dl = pwm_device_link_add(dev, pwm);
802 if (IS_ERR(dl)) {
803 /* of_xlate ended up calling pwm_request_from_chip() */
804 pwm_free(pwm);
805 pwm = ERR_CAST(dl);
806 goto put;
807 }
808
809 /*
810 * If a consumer name was not given, try to look it up from the
811 * "pwm-names" property if it exists. Otherwise use the name of
812 * the user device node.
813 */
814 if (!con_id) {
815 err = of_property_read_string_index(np, "pwm-names", index,
816 &con_id);
817 if (err < 0)
818 con_id = np->name;
819 }
820
821 pwm->label = con_id;
822
823put:
824 of_node_put(args.np);
825
826 return pwm;
827}
828EXPORT_SYMBOL_GPL(of_pwm_get);
829
830/**
831 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
832 * @fwnode: firmware node to get the "pwms" property from
833 *
834 * Returns the PWM device parsed from the fwnode and index specified in the
835 * "pwms" property or a negative error-code on failure.
836 * Values parsed from the device tree are stored in the returned PWM device
837 * object.
838 *
839 * This is analogous to of_pwm_get() except con_id is not yet supported.
840 * ACPI entries must look like
841 * Package () {"pwms", Package ()
842 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
843 *
844 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
845 * error code on failure.
846 */
847static struct pwm_device *acpi_pwm_get(const struct fwnode_handle *fwnode)
848{
849 struct pwm_device *pwm;
850 struct fwnode_reference_args args;
851 struct pwm_chip *chip;
852 int ret;
853
854 memset(&args, 0, sizeof(args));
855
856 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
857 if (ret < 0)
858 return ERR_PTR(ret);
859
860 if (args.nargs < 2)
861 return ERR_PTR(-EPROTO);
862
863 chip = fwnode_to_pwmchip(args.fwnode);
864 if (IS_ERR(chip))
865 return ERR_CAST(chip);
866
867 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
868 if (IS_ERR(pwm))
869 return pwm;
870
871 pwm->args.period = args.args[1];
872 pwm->args.polarity = PWM_POLARITY_NORMAL;
873
874 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
875 pwm->args.polarity = PWM_POLARITY_INVERSED;
876
877 return pwm;
878}
879
880/**
881 * pwm_add_table() - register PWM device consumers
882 * @table: array of consumers to register
883 * @num: number of consumers in table
884 */
885void pwm_add_table(struct pwm_lookup *table, size_t num)
886{
887 mutex_lock(&pwm_lookup_lock);
888
889 while (num--) {
890 list_add_tail(&table->list, &pwm_lookup_list);
891 table++;
892 }
893
894 mutex_unlock(&pwm_lookup_lock);
895}
896
897/**
898 * pwm_remove_table() - unregister PWM device consumers
899 * @table: array of consumers to unregister
900 * @num: number of consumers in table
901 */
902void pwm_remove_table(struct pwm_lookup *table, size_t num)
903{
904 mutex_lock(&pwm_lookup_lock);
905
906 while (num--) {
907 list_del(&table->list);
908 table++;
909 }
910
911 mutex_unlock(&pwm_lookup_lock);
912}
913
914/**
915 * pwm_get() - look up and request a PWM device
916 * @dev: device for PWM consumer
917 * @con_id: consumer name
918 *
919 * Lookup is first attempted using DT. If the device was not instantiated from
920 * a device tree, a PWM chip and a relative index is looked up via a table
921 * supplied by board setup code (see pwm_add_table()).
922 *
923 * Once a PWM chip has been found the specified PWM device will be requested
924 * and is ready to be used.
925 *
926 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
927 * error code on failure.
928 */
929struct pwm_device *pwm_get(struct device *dev, const char *con_id)
930{
931 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
932 const char *dev_id = dev ? dev_name(dev) : NULL;
933 struct pwm_device *pwm;
934 struct pwm_chip *chip;
935 struct device_link *dl;
936 unsigned int best = 0;
937 struct pwm_lookup *p, *chosen = NULL;
938 unsigned int match;
939 int err;
940
941 /* look up via DT first */
942 if (is_of_node(fwnode))
943 return of_pwm_get(dev, to_of_node(fwnode), con_id);
944
945 /* then lookup via ACPI */
946 if (is_acpi_node(fwnode)) {
947 pwm = acpi_pwm_get(fwnode);
948 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
949 return pwm;
950 }
951
952 /*
953 * We look up the provider in the static table typically provided by
954 * board setup code. We first try to lookup the consumer device by
955 * name. If the consumer device was passed in as NULL or if no match
956 * was found, we try to find the consumer by directly looking it up
957 * by name.
958 *
959 * If a match is found, the provider PWM chip is looked up by name
960 * and a PWM device is requested using the PWM device per-chip index.
961 *
962 * The lookup algorithm was shamelessly taken from the clock
963 * framework:
964 *
965 * We do slightly fuzzy matching here:
966 * An entry with a NULL ID is assumed to be a wildcard.
967 * If an entry has a device ID, it must match
968 * If an entry has a connection ID, it must match
969 * Then we take the most specific entry - with the following order
970 * of precedence: dev+con > dev only > con only.
971 */
972 mutex_lock(&pwm_lookup_lock);
973
974 list_for_each_entry(p, &pwm_lookup_list, list) {
975 match = 0;
976
977 if (p->dev_id) {
978 if (!dev_id || strcmp(p->dev_id, dev_id))
979 continue;
980
981 match += 2;
982 }
983
984 if (p->con_id) {
985 if (!con_id || strcmp(p->con_id, con_id))
986 continue;
987
988 match += 1;
989 }
990
991 if (match > best) {
992 chosen = p;
993
994 if (match != 3)
995 best = match;
996 else
997 break;
998 }
999 }
1000
1001 mutex_unlock(&pwm_lookup_lock);
1002
1003 if (!chosen)
1004 return ERR_PTR(-ENODEV);
1005
1006 chip = pwmchip_find_by_name(chosen->provider);
1007
1008 /*
1009 * If the lookup entry specifies a module, load the module and retry
1010 * the PWM chip lookup. This can be used to work around driver load
1011 * ordering issues if driver's can't be made to properly support the
1012 * deferred probe mechanism.
1013 */
1014 if (!chip && chosen->module) {
1015 err = request_module(chosen->module);
1016 if (err == 0)
1017 chip = pwmchip_find_by_name(chosen->provider);
1018 }
1019
1020 if (!chip)
1021 return ERR_PTR(-EPROBE_DEFER);
1022
1023 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
1024 if (IS_ERR(pwm))
1025 return pwm;
1026
1027 dl = pwm_device_link_add(dev, pwm);
1028 if (IS_ERR(dl)) {
1029 pwm_free(pwm);
1030 return ERR_CAST(dl);
1031 }
1032
1033 pwm->args.period = chosen->period;
1034 pwm->args.polarity = chosen->polarity;
1035
1036 return pwm;
1037}
1038EXPORT_SYMBOL_GPL(pwm_get);
1039
1040/**
1041 * pwm_put() - release a PWM device
1042 * @pwm: PWM device
1043 */
1044void pwm_put(struct pwm_device *pwm)
1045{
1046 if (!pwm)
1047 return;
1048
1049 mutex_lock(&pwm_lock);
1050
1051 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
1052 pr_warn("PWM device already freed\n");
1053 goto out;
1054 }
1055
1056 if (pwm->chip->ops->free)
1057 pwm->chip->ops->free(pwm->chip, pwm);
1058
1059 pwm_set_chip_data(pwm, NULL);
1060 pwm->label = NULL;
1061
1062 module_put(pwm->chip->ops->owner);
1063out:
1064 mutex_unlock(&pwm_lock);
1065}
1066EXPORT_SYMBOL_GPL(pwm_put);
1067
1068static void devm_pwm_release(void *pwm)
1069{
1070 pwm_put(pwm);
1071}
1072
1073/**
1074 * devm_pwm_get() - resource managed pwm_get()
1075 * @dev: device for PWM consumer
1076 * @con_id: consumer name
1077 *
1078 * This function performs like pwm_get() but the acquired PWM device will
1079 * automatically be released on driver detach.
1080 *
1081 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1082 * error code on failure.
1083 */
1084struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
1085{
1086 struct pwm_device *pwm;
1087 int ret;
1088
1089 pwm = pwm_get(dev, con_id);
1090 if (IS_ERR(pwm))
1091 return pwm;
1092
1093 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
1094 if (ret)
1095 return ERR_PTR(ret);
1096
1097 return pwm;
1098}
1099EXPORT_SYMBOL_GPL(devm_pwm_get);
1100
1101/**
1102 * devm_of_pwm_get() - resource managed of_pwm_get()
1103 * @dev: device for PWM consumer
1104 * @np: device node to get the PWM from
1105 * @con_id: consumer name
1106 *
1107 * This function performs like of_pwm_get() but the acquired PWM device will
1108 * automatically be released on driver detach.
1109 *
1110 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1111 * error code on failure.
1112 */
1113struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
1114 const char *con_id)
1115{
1116 struct pwm_device *pwm;
1117 int ret;
1118
1119 pwm = of_pwm_get(dev, np, con_id);
1120 if (IS_ERR(pwm))
1121 return pwm;
1122
1123 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
1124 if (ret)
1125 return ERR_PTR(ret);
1126
1127 return pwm;
1128}
1129EXPORT_SYMBOL_GPL(devm_of_pwm_get);
1130
1131/**
1132 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
1133 * @dev: device for PWM consumer
1134 * @fwnode: firmware node to get the PWM from
1135 * @con_id: consumer name
1136 *
1137 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
1138 * acpi_pwm_get() for a detailed description.
1139 *
1140 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1141 * error code on failure.
1142 */
1143struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
1144 struct fwnode_handle *fwnode,
1145 const char *con_id)
1146{
1147 struct pwm_device *pwm = ERR_PTR(-ENODEV);
1148 int ret;
1149
1150 if (is_of_node(fwnode))
1151 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1152 else if (is_acpi_node(fwnode))
1153 pwm = acpi_pwm_get(fwnode);
1154 if (IS_ERR(pwm))
1155 return pwm;
1156
1157 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
1158 if (ret)
1159 return ERR_PTR(ret);
1160
1161 return pwm;
1162}
1163EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1164
1165#ifdef CONFIG_DEBUG_FS
1166static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1167{
1168 unsigned int i;
1169
1170 for (i = 0; i < chip->npwm; i++) {
1171 struct pwm_device *pwm = &chip->pwms[i];
1172 struct pwm_state state;
1173
1174 pwm_get_state(pwm, &state);
1175
1176 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1177
1178 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1179 seq_puts(s, " requested");
1180
1181 if (state.enabled)
1182 seq_puts(s, " enabled");
1183
1184 seq_printf(s, " period: %llu ns", state.period);
1185 seq_printf(s, " duty: %llu ns", state.duty_cycle);
1186 seq_printf(s, " polarity: %s",
1187 state.polarity ? "inverse" : "normal");
1188
1189 if (state.usage_power)
1190 seq_puts(s, " usage_power");
1191
1192 seq_puts(s, "\n");
1193 }
1194}
1195
1196static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1197{
1198 mutex_lock(&pwm_lock);
1199 s->private = "";
1200
1201 return seq_list_start(&pwm_chips, *pos);
1202}
1203
1204static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1205{
1206 s->private = "\n";
1207
1208 return seq_list_next(v, &pwm_chips, pos);
1209}
1210
1211static void pwm_seq_stop(struct seq_file *s, void *v)
1212{
1213 mutex_unlock(&pwm_lock);
1214}
1215
1216static int pwm_seq_show(struct seq_file *s, void *v)
1217{
1218 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1219
1220 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1221 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1222 dev_name(chip->dev), chip->npwm,
1223 (chip->npwm != 1) ? "s" : "");
1224
1225 pwm_dbg_show(chip, s);
1226
1227 return 0;
1228}
1229
1230static const struct seq_operations pwm_debugfs_sops = {
1231 .start = pwm_seq_start,
1232 .next = pwm_seq_next,
1233 .stop = pwm_seq_stop,
1234 .show = pwm_seq_show,
1235};
1236
1237DEFINE_SEQ_ATTRIBUTE(pwm_debugfs);
1238
1239static int __init pwm_debugfs_init(void)
1240{
1241 debugfs_create_file("pwm", S_IFREG | 0444, NULL, NULL,
1242 &pwm_debugfs_fops);
1243
1244 return 0;
1245}
1246subsys_initcall(pwm_debugfs_init);
1247#endif /* CONFIG_DEBUG_FS */