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