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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/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(int pwm, unsigned int count)
41{
42 unsigned int from = 0;
43 unsigned int start;
44
45 if (pwm >= MAX_PWMS)
46 return -EINVAL;
47
48 if (pwm >= 0)
49 from = pwm;
50
51 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
52 count, 0);
53
54 if (pwm >= 0 && start != pwm)
55 return -EEXIST;
56
57 if (start + count > MAX_PWMS)
58 return -ENOSPC;
59
60 return start;
61}
62
63static void free_pwms(struct pwm_chip *chip)
64{
65 unsigned int i;
66
67 for (i = 0; i < chip->npwm; i++) {
68 struct pwm_device *pwm = &chip->pwms[i];
69
70 radix_tree_delete(&pwm_tree, pwm->pwm);
71 }
72
73 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
74
75 kfree(chip->pwms);
76 chip->pwms = NULL;
77}
78
79static struct pwm_chip *pwmchip_find_by_name(const char *name)
80{
81 struct pwm_chip *chip;
82
83 if (!name)
84 return NULL;
85
86 mutex_lock(&pwm_lock);
87
88 list_for_each_entry(chip, &pwm_chips, list) {
89 const char *chip_name = dev_name(chip->dev);
90
91 if (chip_name && strcmp(chip_name, name) == 0) {
92 mutex_unlock(&pwm_lock);
93 return chip;
94 }
95 }
96
97 mutex_unlock(&pwm_lock);
98
99 return NULL;
100}
101
102static int pwm_device_request(struct pwm_device *pwm, const char *label)
103{
104 int err;
105
106 if (test_bit(PWMF_REQUESTED, &pwm->flags))
107 return -EBUSY;
108
109 if (!try_module_get(pwm->chip->ops->owner))
110 return -ENODEV;
111
112 if (pwm->chip->ops->request) {
113 err = pwm->chip->ops->request(pwm->chip, pwm);
114 if (err) {
115 module_put(pwm->chip->ops->owner);
116 return err;
117 }
118 }
119
120 if (pwm->chip->ops->get_state) {
121 pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state);
122 trace_pwm_get(pwm, &pwm->state);
123
124 if (IS_ENABLED(CONFIG_PWM_DEBUG))
125 pwm->last = pwm->state;
126 }
127
128 set_bit(PWMF_REQUESTED, &pwm->flags);
129 pwm->label = label;
130
131 return 0;
132}
133
134struct pwm_device *
135of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
136{
137 struct pwm_device *pwm;
138
139 /* check, whether the driver supports a third cell for flags */
140 if (pc->of_pwm_n_cells < 3)
141 return ERR_PTR(-EINVAL);
142
143 /* flags in the third cell are optional */
144 if (args->args_count < 2)
145 return ERR_PTR(-EINVAL);
146
147 if (args->args[0] >= pc->npwm)
148 return ERR_PTR(-EINVAL);
149
150 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
151 if (IS_ERR(pwm))
152 return pwm;
153
154 pwm->args.period = args->args[1];
155 pwm->args.polarity = PWM_POLARITY_NORMAL;
156
157 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
158 pwm->args.polarity = PWM_POLARITY_INVERSED;
159
160 return pwm;
161}
162EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
163
164static struct pwm_device *
165of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
166{
167 struct pwm_device *pwm;
168
169 /* sanity check driver support */
170 if (pc->of_pwm_n_cells < 2)
171 return ERR_PTR(-EINVAL);
172
173 /* all cells are required */
174 if (args->args_count != pc->of_pwm_n_cells)
175 return ERR_PTR(-EINVAL);
176
177 if (args->args[0] >= pc->npwm)
178 return ERR_PTR(-EINVAL);
179
180 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
181 if (IS_ERR(pwm))
182 return pwm;
183
184 pwm->args.period = args->args[1];
185
186 return pwm;
187}
188
189static void of_pwmchip_add(struct pwm_chip *chip)
190{
191 if (!chip->dev || !chip->dev->of_node)
192 return;
193
194 if (!chip->of_xlate) {
195 chip->of_xlate = of_pwm_simple_xlate;
196 chip->of_pwm_n_cells = 2;
197 }
198
199 of_node_get(chip->dev->of_node);
200}
201
202static void of_pwmchip_remove(struct pwm_chip *chip)
203{
204 if (chip->dev)
205 of_node_put(chip->dev->of_node);
206}
207
208/**
209 * pwm_set_chip_data() - set private chip data for a PWM
210 * @pwm: PWM device
211 * @data: pointer to chip-specific data
212 *
213 * Returns: 0 on success or a negative error code on failure.
214 */
215int pwm_set_chip_data(struct pwm_device *pwm, void *data)
216{
217 if (!pwm)
218 return -EINVAL;
219
220 pwm->chip_data = data;
221
222 return 0;
223}
224EXPORT_SYMBOL_GPL(pwm_set_chip_data);
225
226/**
227 * pwm_get_chip_data() - get private chip data for a PWM
228 * @pwm: PWM device
229 *
230 * Returns: A pointer to the chip-private data for the PWM device.
231 */
232void *pwm_get_chip_data(struct pwm_device *pwm)
233{
234 return pwm ? pwm->chip_data : NULL;
235}
236EXPORT_SYMBOL_GPL(pwm_get_chip_data);
237
238static bool pwm_ops_check(const struct pwm_chip *chip)
239{
240
241 const struct pwm_ops *ops = chip->ops;
242
243 /* driver supports legacy, non-atomic operation */
244 if (ops->config && ops->enable && ops->disable) {
245 if (IS_ENABLED(CONFIG_PWM_DEBUG))
246 dev_warn(chip->dev,
247 "Driver needs updating to atomic API\n");
248
249 return true;
250 }
251
252 if (!ops->apply)
253 return false;
254
255 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
256 dev_warn(chip->dev,
257 "Please implement the .get_state() callback\n");
258
259 return true;
260}
261
262/**
263 * pwmchip_add_with_polarity() - register a new PWM chip
264 * @chip: the PWM chip to add
265 * @polarity: initial polarity of PWM channels
266 *
267 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
268 * will be used. The initial polarity for all channels is specified by the
269 * @polarity parameter.
270 *
271 * Returns: 0 on success or a negative error code on failure.
272 */
273int pwmchip_add_with_polarity(struct pwm_chip *chip,
274 enum pwm_polarity polarity)
275{
276 struct pwm_device *pwm;
277 unsigned int i;
278 int ret;
279
280 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
281 return -EINVAL;
282
283 if (!pwm_ops_check(chip))
284 return -EINVAL;
285
286 mutex_lock(&pwm_lock);
287
288 ret = alloc_pwms(chip->base, chip->npwm);
289 if (ret < 0)
290 goto out;
291
292 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
293 if (!chip->pwms) {
294 ret = -ENOMEM;
295 goto out;
296 }
297
298 chip->base = ret;
299
300 for (i = 0; i < chip->npwm; i++) {
301 pwm = &chip->pwms[i];
302
303 pwm->chip = chip;
304 pwm->pwm = chip->base + i;
305 pwm->hwpwm = i;
306 pwm->state.polarity = polarity;
307
308 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
309 }
310
311 bitmap_set(allocated_pwms, chip->base, chip->npwm);
312
313 INIT_LIST_HEAD(&chip->list);
314 list_add(&chip->list, &pwm_chips);
315
316 ret = 0;
317
318 if (IS_ENABLED(CONFIG_OF))
319 of_pwmchip_add(chip);
320
321out:
322 mutex_unlock(&pwm_lock);
323
324 if (!ret)
325 pwmchip_sysfs_export(chip);
326
327 return ret;
328}
329EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity);
330
331/**
332 * pwmchip_add() - register a new PWM chip
333 * @chip: the PWM chip to add
334 *
335 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
336 * will be used. The initial polarity for all channels is normal.
337 *
338 * Returns: 0 on success or a negative error code on failure.
339 */
340int pwmchip_add(struct pwm_chip *chip)
341{
342 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
343}
344EXPORT_SYMBOL_GPL(pwmchip_add);
345
346/**
347 * pwmchip_remove() - remove a PWM chip
348 * @chip: the PWM chip to remove
349 *
350 * Removes a PWM chip. This function may return busy if the PWM chip provides
351 * a PWM device that is still requested.
352 *
353 * Returns: 0 on success or a negative error code on failure.
354 */
355int pwmchip_remove(struct pwm_chip *chip)
356{
357 unsigned int i;
358 int ret = 0;
359
360 pwmchip_sysfs_unexport(chip);
361
362 mutex_lock(&pwm_lock);
363
364 for (i = 0; i < chip->npwm; i++) {
365 struct pwm_device *pwm = &chip->pwms[i];
366
367 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
368 ret = -EBUSY;
369 goto out;
370 }
371 }
372
373 list_del_init(&chip->list);
374
375 if (IS_ENABLED(CONFIG_OF))
376 of_pwmchip_remove(chip);
377
378 free_pwms(chip);
379
380out:
381 mutex_unlock(&pwm_lock);
382 return ret;
383}
384EXPORT_SYMBOL_GPL(pwmchip_remove);
385
386/**
387 * pwm_request() - request a PWM device
388 * @pwm: global PWM device index
389 * @label: PWM device label
390 *
391 * This function is deprecated, use pwm_get() instead.
392 *
393 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
394 * failure.
395 */
396struct pwm_device *pwm_request(int pwm, const char *label)
397{
398 struct pwm_device *dev;
399 int err;
400
401 if (pwm < 0 || pwm >= MAX_PWMS)
402 return ERR_PTR(-EINVAL);
403
404 mutex_lock(&pwm_lock);
405
406 dev = pwm_to_device(pwm);
407 if (!dev) {
408 dev = ERR_PTR(-EPROBE_DEFER);
409 goto out;
410 }
411
412 err = pwm_device_request(dev, label);
413 if (err < 0)
414 dev = ERR_PTR(err);
415
416out:
417 mutex_unlock(&pwm_lock);
418
419 return dev;
420}
421EXPORT_SYMBOL_GPL(pwm_request);
422
423/**
424 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
425 * @chip: PWM chip
426 * @index: per-chip index of the PWM to request
427 * @label: a literal description string of this PWM
428 *
429 * Returns: A pointer to the PWM device at the given index of the given PWM
430 * chip. A negative error code is returned if the index is not valid for the
431 * specified PWM chip or if the PWM device cannot be requested.
432 */
433struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
434 unsigned int index,
435 const char *label)
436{
437 struct pwm_device *pwm;
438 int err;
439
440 if (!chip || index >= chip->npwm)
441 return ERR_PTR(-EINVAL);
442
443 mutex_lock(&pwm_lock);
444 pwm = &chip->pwms[index];
445
446 err = pwm_device_request(pwm, label);
447 if (err < 0)
448 pwm = ERR_PTR(err);
449
450 mutex_unlock(&pwm_lock);
451 return pwm;
452}
453EXPORT_SYMBOL_GPL(pwm_request_from_chip);
454
455/**
456 * pwm_free() - free a PWM device
457 * @pwm: PWM device
458 *
459 * This function is deprecated, use pwm_put() instead.
460 */
461void pwm_free(struct pwm_device *pwm)
462{
463 pwm_put(pwm);
464}
465EXPORT_SYMBOL_GPL(pwm_free);
466
467static void pwm_apply_state_debug(struct pwm_device *pwm,
468 const struct pwm_state *state)
469{
470 struct pwm_state *last = &pwm->last;
471 struct pwm_chip *chip = pwm->chip;
472 struct pwm_state s1, s2;
473 int err;
474
475 if (!IS_ENABLED(CONFIG_PWM_DEBUG))
476 return;
477
478 /* No reasonable diagnosis possible without .get_state() */
479 if (!chip->ops->get_state)
480 return;
481
482 /*
483 * *state was just applied. Read out the hardware state and do some
484 * checks.
485 */
486
487 chip->ops->get_state(chip, pwm, &s1);
488 trace_pwm_get(pwm, &s1);
489
490 /*
491 * The lowlevel driver either ignored .polarity (which is a bug) or as
492 * best effort inverted .polarity and fixed .duty_cycle respectively.
493 * Undo this inversion and fixup for further tests.
494 */
495 if (s1.enabled && s1.polarity != state->polarity) {
496 s2.polarity = state->polarity;
497 s2.duty_cycle = s1.period - s1.duty_cycle;
498 s2.period = s1.period;
499 s2.enabled = s1.enabled;
500 } else {
501 s2 = s1;
502 }
503
504 if (s2.polarity != state->polarity &&
505 state->duty_cycle < state->period)
506 dev_warn(chip->dev, ".apply ignored .polarity\n");
507
508 if (state->enabled &&
509 last->polarity == state->polarity &&
510 last->period > s2.period &&
511 last->period <= state->period)
512 dev_warn(chip->dev,
513 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
514 state->period, s2.period, last->period);
515
516 if (state->enabled && state->period < s2.period)
517 dev_warn(chip->dev,
518 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
519 state->period, s2.period);
520
521 if (state->enabled &&
522 last->polarity == state->polarity &&
523 last->period == s2.period &&
524 last->duty_cycle > s2.duty_cycle &&
525 last->duty_cycle <= state->duty_cycle)
526 dev_warn(chip->dev,
527 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
528 state->duty_cycle, state->period,
529 s2.duty_cycle, s2.period,
530 last->duty_cycle, last->period);
531
532 if (state->enabled && state->duty_cycle < s2.duty_cycle)
533 dev_warn(chip->dev,
534 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
535 state->duty_cycle, state->period,
536 s2.duty_cycle, s2.period);
537
538 if (!state->enabled && s2.enabled && s2.duty_cycle > 0)
539 dev_warn(chip->dev,
540 "requested disabled, but yielded enabled with duty > 0\n");
541
542 /* reapply the state that the driver reported being configured. */
543 err = chip->ops->apply(chip, pwm, &s1);
544 if (err) {
545 *last = s1;
546 dev_err(chip->dev, "failed to reapply current setting\n");
547 return;
548 }
549
550 trace_pwm_apply(pwm, &s1);
551
552 chip->ops->get_state(chip, pwm, last);
553 trace_pwm_get(pwm, last);
554
555 /* reapplication of the current state should give an exact match */
556 if (s1.enabled != last->enabled ||
557 s1.polarity != last->polarity ||
558 (s1.enabled && s1.period != last->period) ||
559 (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
560 dev_err(chip->dev,
561 ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
562 s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
563 last->enabled, last->polarity, last->duty_cycle,
564 last->period);
565 }
566}
567
568/**
569 * pwm_apply_state() - atomically apply a new state to a PWM device
570 * @pwm: PWM device
571 * @state: new state to apply
572 */
573int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
574{
575 struct pwm_chip *chip;
576 int err;
577
578 if (!pwm || !state || !state->period ||
579 state->duty_cycle > state->period)
580 return -EINVAL;
581
582 chip = pwm->chip;
583
584 if (state->period == pwm->state.period &&
585 state->duty_cycle == pwm->state.duty_cycle &&
586 state->polarity == pwm->state.polarity &&
587 state->enabled == pwm->state.enabled)
588 return 0;
589
590 if (chip->ops->apply) {
591 err = chip->ops->apply(chip, pwm, state);
592 if (err)
593 return err;
594
595 trace_pwm_apply(pwm, state);
596
597 pwm->state = *state;
598
599 /*
600 * only do this after pwm->state was applied as some
601 * implementations of .get_state depend on this
602 */
603 pwm_apply_state_debug(pwm, state);
604 } else {
605 /*
606 * FIXME: restore the initial state in case of error.
607 */
608 if (state->polarity != pwm->state.polarity) {
609 if (!chip->ops->set_polarity)
610 return -ENOTSUPP;
611
612 /*
613 * Changing the polarity of a running PWM is
614 * only allowed when the PWM driver implements
615 * ->apply().
616 */
617 if (pwm->state.enabled) {
618 chip->ops->disable(chip, pwm);
619 pwm->state.enabled = false;
620 }
621
622 err = chip->ops->set_polarity(chip, pwm,
623 state->polarity);
624 if (err)
625 return err;
626
627 pwm->state.polarity = state->polarity;
628 }
629
630 if (state->period != pwm->state.period ||
631 state->duty_cycle != pwm->state.duty_cycle) {
632 err = chip->ops->config(pwm->chip, pwm,
633 state->duty_cycle,
634 state->period);
635 if (err)
636 return err;
637
638 pwm->state.duty_cycle = state->duty_cycle;
639 pwm->state.period = state->period;
640 }
641
642 if (state->enabled != pwm->state.enabled) {
643 if (state->enabled) {
644 err = chip->ops->enable(chip, pwm);
645 if (err)
646 return err;
647 } else {
648 chip->ops->disable(chip, pwm);
649 }
650
651 pwm->state.enabled = state->enabled;
652 }
653 }
654
655 return 0;
656}
657EXPORT_SYMBOL_GPL(pwm_apply_state);
658
659/**
660 * pwm_capture() - capture and report a PWM signal
661 * @pwm: PWM device
662 * @result: structure to fill with capture result
663 * @timeout: time to wait, in milliseconds, before giving up on capture
664 *
665 * Returns: 0 on success or a negative error code on failure.
666 */
667int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
668 unsigned long timeout)
669{
670 int err;
671
672 if (!pwm || !pwm->chip->ops)
673 return -EINVAL;
674
675 if (!pwm->chip->ops->capture)
676 return -ENOSYS;
677
678 mutex_lock(&pwm_lock);
679 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
680 mutex_unlock(&pwm_lock);
681
682 return err;
683}
684EXPORT_SYMBOL_GPL(pwm_capture);
685
686/**
687 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
688 * @pwm: PWM device
689 *
690 * This function will adjust the PWM config to the PWM arguments provided
691 * by the DT or PWM lookup table. This is particularly useful to adapt
692 * the bootloader config to the Linux one.
693 */
694int pwm_adjust_config(struct pwm_device *pwm)
695{
696 struct pwm_state state;
697 struct pwm_args pargs;
698
699 pwm_get_args(pwm, &pargs);
700 pwm_get_state(pwm, &state);
701
702 /*
703 * If the current period is zero it means that either the PWM driver
704 * does not support initial state retrieval or the PWM has not yet
705 * been configured.
706 *
707 * In either case, we setup the new period and polarity, and assign a
708 * duty cycle of 0.
709 */
710 if (!state.period) {
711 state.duty_cycle = 0;
712 state.period = pargs.period;
713 state.polarity = pargs.polarity;
714
715 return pwm_apply_state(pwm, &state);
716 }
717
718 /*
719 * Adjust the PWM duty cycle/period based on the period value provided
720 * in PWM args.
721 */
722 if (pargs.period != state.period) {
723 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
724
725 do_div(dutycycle, state.period);
726 state.duty_cycle = dutycycle;
727 state.period = pargs.period;
728 }
729
730 /*
731 * If the polarity changed, we should also change the duty cycle.
732 */
733 if (pargs.polarity != state.polarity) {
734 state.polarity = pargs.polarity;
735 state.duty_cycle = state.period - state.duty_cycle;
736 }
737
738 return pwm_apply_state(pwm, &state);
739}
740EXPORT_SYMBOL_GPL(pwm_adjust_config);
741
742static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
743{
744 struct pwm_chip *chip;
745
746 mutex_lock(&pwm_lock);
747
748 list_for_each_entry(chip, &pwm_chips, list)
749 if (chip->dev && chip->dev->of_node == np) {
750 mutex_unlock(&pwm_lock);
751 return chip;
752 }
753
754 mutex_unlock(&pwm_lock);
755
756 return ERR_PTR(-EPROBE_DEFER);
757}
758
759static struct device_link *pwm_device_link_add(struct device *dev,
760 struct pwm_device *pwm)
761{
762 struct device_link *dl;
763
764 if (!dev) {
765 /*
766 * No device for the PWM consumer has been provided. It may
767 * impact the PM sequence ordering: the PWM supplier may get
768 * suspended before the consumer.
769 */
770 dev_warn(pwm->chip->dev,
771 "No consumer device specified to create a link to\n");
772 return NULL;
773 }
774
775 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
776 if (!dl) {
777 dev_err(dev, "failed to create device link to %s\n",
778 dev_name(pwm->chip->dev));
779 return ERR_PTR(-EINVAL);
780 }
781
782 return dl;
783}
784
785/**
786 * of_pwm_get() - request a PWM via the PWM framework
787 * @dev: device for PWM consumer
788 * @np: device node to get the PWM from
789 * @con_id: consumer name
790 *
791 * Returns the PWM device parsed from the phandle and index specified in the
792 * "pwms" property of a device tree node or a negative error-code on failure.
793 * Values parsed from the device tree are stored in the returned PWM device
794 * object.
795 *
796 * If con_id is NULL, the first PWM device listed in the "pwms" property will
797 * be requested. Otherwise the "pwm-names" property is used to do a reverse
798 * lookup of the PWM index. This also means that the "pwm-names" property
799 * becomes mandatory for devices that look up the PWM device via the con_id
800 * parameter.
801 *
802 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
803 * error code on failure.
804 */
805struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
806 const char *con_id)
807{
808 struct pwm_device *pwm = NULL;
809 struct of_phandle_args args;
810 struct device_link *dl;
811 struct pwm_chip *pc;
812 int index = 0;
813 int err;
814
815 if (con_id) {
816 index = of_property_match_string(np, "pwm-names", con_id);
817 if (index < 0)
818 return ERR_PTR(index);
819 }
820
821 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
822 &args);
823 if (err) {
824 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
825 return ERR_PTR(err);
826 }
827
828 pc = of_node_to_pwmchip(args.np);
829 if (IS_ERR(pc)) {
830 if (PTR_ERR(pc) != -EPROBE_DEFER)
831 pr_err("%s(): PWM chip not found\n", __func__);
832
833 pwm = ERR_CAST(pc);
834 goto put;
835 }
836
837 pwm = pc->of_xlate(pc, &args);
838 if (IS_ERR(pwm))
839 goto put;
840
841 dl = pwm_device_link_add(dev, pwm);
842 if (IS_ERR(dl)) {
843 /* of_xlate ended up calling pwm_request_from_chip() */
844 pwm_free(pwm);
845 pwm = ERR_CAST(dl);
846 goto put;
847 }
848
849 /*
850 * If a consumer name was not given, try to look it up from the
851 * "pwm-names" property if it exists. Otherwise use the name of
852 * the user device node.
853 */
854 if (!con_id) {
855 err = of_property_read_string_index(np, "pwm-names", index,
856 &con_id);
857 if (err < 0)
858 con_id = np->name;
859 }
860
861 pwm->label = con_id;
862
863put:
864 of_node_put(args.np);
865
866 return pwm;
867}
868EXPORT_SYMBOL_GPL(of_pwm_get);
869
870#if IS_ENABLED(CONFIG_ACPI)
871static struct pwm_chip *device_to_pwmchip(struct device *dev)
872{
873 struct pwm_chip *chip;
874
875 mutex_lock(&pwm_lock);
876
877 list_for_each_entry(chip, &pwm_chips, list) {
878 struct acpi_device *adev = ACPI_COMPANION(chip->dev);
879
880 if ((chip->dev == dev) || (adev && &adev->dev == dev)) {
881 mutex_unlock(&pwm_lock);
882 return chip;
883 }
884 }
885
886 mutex_unlock(&pwm_lock);
887
888 return ERR_PTR(-EPROBE_DEFER);
889}
890#endif
891
892/**
893 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
894 * @fwnode: firmware node to get the "pwm" property from
895 *
896 * Returns the PWM device parsed from the fwnode and index specified in the
897 * "pwms" property or a negative error-code on failure.
898 * Values parsed from the device tree are stored in the returned PWM device
899 * object.
900 *
901 * This is analogous to of_pwm_get() except con_id is not yet supported.
902 * ACPI entries must look like
903 * Package () {"pwms", Package ()
904 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
905 *
906 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
907 * error code on failure.
908 */
909static struct pwm_device *acpi_pwm_get(struct fwnode_handle *fwnode)
910{
911 struct pwm_device *pwm = ERR_PTR(-ENODEV);
912#if IS_ENABLED(CONFIG_ACPI)
913 struct fwnode_reference_args args;
914 struct acpi_device *acpi;
915 struct pwm_chip *chip;
916 int ret;
917
918 memset(&args, 0, sizeof(args));
919
920 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
921 if (ret < 0)
922 return ERR_PTR(ret);
923
924 acpi = to_acpi_device_node(args.fwnode);
925 if (!acpi)
926 return ERR_PTR(-EINVAL);
927
928 if (args.nargs < 2)
929 return ERR_PTR(-EPROTO);
930
931 chip = device_to_pwmchip(&acpi->dev);
932 if (IS_ERR(chip))
933 return ERR_CAST(chip);
934
935 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
936 if (IS_ERR(pwm))
937 return pwm;
938
939 pwm->args.period = args.args[1];
940 pwm->args.polarity = PWM_POLARITY_NORMAL;
941
942 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
943 pwm->args.polarity = PWM_POLARITY_INVERSED;
944#endif
945
946 return pwm;
947}
948
949/**
950 * pwm_add_table() - register PWM device consumers
951 * @table: array of consumers to register
952 * @num: number of consumers in table
953 */
954void pwm_add_table(struct pwm_lookup *table, size_t num)
955{
956 mutex_lock(&pwm_lookup_lock);
957
958 while (num--) {
959 list_add_tail(&table->list, &pwm_lookup_list);
960 table++;
961 }
962
963 mutex_unlock(&pwm_lookup_lock);
964}
965
966/**
967 * pwm_remove_table() - unregister PWM device consumers
968 * @table: array of consumers to unregister
969 * @num: number of consumers in table
970 */
971void pwm_remove_table(struct pwm_lookup *table, size_t num)
972{
973 mutex_lock(&pwm_lookup_lock);
974
975 while (num--) {
976 list_del(&table->list);
977 table++;
978 }
979
980 mutex_unlock(&pwm_lookup_lock);
981}
982
983/**
984 * pwm_get() - look up and request a PWM device
985 * @dev: device for PWM consumer
986 * @con_id: consumer name
987 *
988 * Lookup is first attempted using DT. If the device was not instantiated from
989 * a device tree, a PWM chip and a relative index is looked up via a table
990 * supplied by board setup code (see pwm_add_table()).
991 *
992 * Once a PWM chip has been found the specified PWM device will be requested
993 * and is ready to be used.
994 *
995 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
996 * error code on failure.
997 */
998struct pwm_device *pwm_get(struct device *dev, const char *con_id)
999{
1000 const char *dev_id = dev ? dev_name(dev) : NULL;
1001 struct pwm_device *pwm;
1002 struct pwm_chip *chip;
1003 struct device_link *dl;
1004 unsigned int best = 0;
1005 struct pwm_lookup *p, *chosen = NULL;
1006 unsigned int match;
1007 int err;
1008
1009 /* look up via DT first */
1010 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
1011 return of_pwm_get(dev, dev->of_node, con_id);
1012
1013 /* then lookup via ACPI */
1014 if (dev && is_acpi_node(dev->fwnode)) {
1015 pwm = acpi_pwm_get(dev->fwnode);
1016 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
1017 return pwm;
1018 }
1019
1020 /*
1021 * We look up the provider in the static table typically provided by
1022 * board setup code. We first try to lookup the consumer device by
1023 * name. If the consumer device was passed in as NULL or if no match
1024 * was found, we try to find the consumer by directly looking it up
1025 * by name.
1026 *
1027 * If a match is found, the provider PWM chip is looked up by name
1028 * and a PWM device is requested using the PWM device per-chip index.
1029 *
1030 * The lookup algorithm was shamelessly taken from the clock
1031 * framework:
1032 *
1033 * We do slightly fuzzy matching here:
1034 * An entry with a NULL ID is assumed to be a wildcard.
1035 * If an entry has a device ID, it must match
1036 * If an entry has a connection ID, it must match
1037 * Then we take the most specific entry - with the following order
1038 * of precedence: dev+con > dev only > con only.
1039 */
1040 mutex_lock(&pwm_lookup_lock);
1041
1042 list_for_each_entry(p, &pwm_lookup_list, list) {
1043 match = 0;
1044
1045 if (p->dev_id) {
1046 if (!dev_id || strcmp(p->dev_id, dev_id))
1047 continue;
1048
1049 match += 2;
1050 }
1051
1052 if (p->con_id) {
1053 if (!con_id || strcmp(p->con_id, con_id))
1054 continue;
1055
1056 match += 1;
1057 }
1058
1059 if (match > best) {
1060 chosen = p;
1061
1062 if (match != 3)
1063 best = match;
1064 else
1065 break;
1066 }
1067 }
1068
1069 mutex_unlock(&pwm_lookup_lock);
1070
1071 if (!chosen)
1072 return ERR_PTR(-ENODEV);
1073
1074 chip = pwmchip_find_by_name(chosen->provider);
1075
1076 /*
1077 * If the lookup entry specifies a module, load the module and retry
1078 * the PWM chip lookup. This can be used to work around driver load
1079 * ordering issues if driver's can't be made to properly support the
1080 * deferred probe mechanism.
1081 */
1082 if (!chip && chosen->module) {
1083 err = request_module(chosen->module);
1084 if (err == 0)
1085 chip = pwmchip_find_by_name(chosen->provider);
1086 }
1087
1088 if (!chip)
1089 return ERR_PTR(-EPROBE_DEFER);
1090
1091 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
1092 if (IS_ERR(pwm))
1093 return pwm;
1094
1095 dl = pwm_device_link_add(dev, pwm);
1096 if (IS_ERR(dl)) {
1097 pwm_free(pwm);
1098 return ERR_CAST(dl);
1099 }
1100
1101 pwm->args.period = chosen->period;
1102 pwm->args.polarity = chosen->polarity;
1103
1104 return pwm;
1105}
1106EXPORT_SYMBOL_GPL(pwm_get);
1107
1108/**
1109 * pwm_put() - release a PWM device
1110 * @pwm: PWM device
1111 */
1112void pwm_put(struct pwm_device *pwm)
1113{
1114 if (!pwm)
1115 return;
1116
1117 mutex_lock(&pwm_lock);
1118
1119 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
1120 pr_warn("PWM device already freed\n");
1121 goto out;
1122 }
1123
1124 if (pwm->chip->ops->free)
1125 pwm->chip->ops->free(pwm->chip, pwm);
1126
1127 pwm_set_chip_data(pwm, NULL);
1128 pwm->label = NULL;
1129
1130 module_put(pwm->chip->ops->owner);
1131out:
1132 mutex_unlock(&pwm_lock);
1133}
1134EXPORT_SYMBOL_GPL(pwm_put);
1135
1136static void devm_pwm_release(struct device *dev, void *res)
1137{
1138 pwm_put(*(struct pwm_device **)res);
1139}
1140
1141/**
1142 * devm_pwm_get() - resource managed pwm_get()
1143 * @dev: device for PWM consumer
1144 * @con_id: consumer name
1145 *
1146 * This function performs like pwm_get() but the acquired PWM device will
1147 * automatically be released on driver detach.
1148 *
1149 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1150 * error code on failure.
1151 */
1152struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
1153{
1154 struct pwm_device **ptr, *pwm;
1155
1156 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1157 if (!ptr)
1158 return ERR_PTR(-ENOMEM);
1159
1160 pwm = pwm_get(dev, con_id);
1161 if (!IS_ERR(pwm)) {
1162 *ptr = pwm;
1163 devres_add(dev, ptr);
1164 } else {
1165 devres_free(ptr);
1166 }
1167
1168 return pwm;
1169}
1170EXPORT_SYMBOL_GPL(devm_pwm_get);
1171
1172/**
1173 * devm_of_pwm_get() - resource managed of_pwm_get()
1174 * @dev: device for PWM consumer
1175 * @np: device node to get the PWM from
1176 * @con_id: consumer name
1177 *
1178 * This function performs like of_pwm_get() but the acquired PWM device will
1179 * automatically be released on driver detach.
1180 *
1181 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1182 * error code on failure.
1183 */
1184struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
1185 const char *con_id)
1186{
1187 struct pwm_device **ptr, *pwm;
1188
1189 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1190 if (!ptr)
1191 return ERR_PTR(-ENOMEM);
1192
1193 pwm = of_pwm_get(dev, np, con_id);
1194 if (!IS_ERR(pwm)) {
1195 *ptr = pwm;
1196 devres_add(dev, ptr);
1197 } else {
1198 devres_free(ptr);
1199 }
1200
1201 return pwm;
1202}
1203EXPORT_SYMBOL_GPL(devm_of_pwm_get);
1204
1205/**
1206 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
1207 * @dev: device for PWM consumer
1208 * @fwnode: firmware node to get the PWM from
1209 * @con_id: consumer name
1210 *
1211 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
1212 * acpi_pwm_get() for a detailed description.
1213 *
1214 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1215 * error code on failure.
1216 */
1217struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
1218 struct fwnode_handle *fwnode,
1219 const char *con_id)
1220{
1221 struct pwm_device **ptr, *pwm = ERR_PTR(-ENODEV);
1222
1223 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1224 if (!ptr)
1225 return ERR_PTR(-ENOMEM);
1226
1227 if (is_of_node(fwnode))
1228 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1229 else if (is_acpi_node(fwnode))
1230 pwm = acpi_pwm_get(fwnode);
1231
1232 if (!IS_ERR(pwm)) {
1233 *ptr = pwm;
1234 devres_add(dev, ptr);
1235 } else {
1236 devres_free(ptr);
1237 }
1238
1239 return pwm;
1240}
1241EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1242
1243static int devm_pwm_match(struct device *dev, void *res, void *data)
1244{
1245 struct pwm_device **p = res;
1246
1247 if (WARN_ON(!p || !*p))
1248 return 0;
1249
1250 return *p == data;
1251}
1252
1253/**
1254 * devm_pwm_put() - resource managed pwm_put()
1255 * @dev: device for PWM consumer
1256 * @pwm: PWM device
1257 *
1258 * Release a PWM previously allocated using devm_pwm_get(). Calling this
1259 * function is usually not needed because devm-allocated resources are
1260 * automatically released on driver detach.
1261 */
1262void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
1263{
1264 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
1265}
1266EXPORT_SYMBOL_GPL(devm_pwm_put);
1267
1268#ifdef CONFIG_DEBUG_FS
1269static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1270{
1271 unsigned int i;
1272
1273 for (i = 0; i < chip->npwm; i++) {
1274 struct pwm_device *pwm = &chip->pwms[i];
1275 struct pwm_state state;
1276
1277 pwm_get_state(pwm, &state);
1278
1279 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1280
1281 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1282 seq_puts(s, " requested");
1283
1284 if (state.enabled)
1285 seq_puts(s, " enabled");
1286
1287 seq_printf(s, " period: %llu ns", state.period);
1288 seq_printf(s, " duty: %llu ns", state.duty_cycle);
1289 seq_printf(s, " polarity: %s",
1290 state.polarity ? "inverse" : "normal");
1291
1292 seq_puts(s, "\n");
1293 }
1294}
1295
1296static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1297{
1298 mutex_lock(&pwm_lock);
1299 s->private = "";
1300
1301 return seq_list_start(&pwm_chips, *pos);
1302}
1303
1304static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1305{
1306 s->private = "\n";
1307
1308 return seq_list_next(v, &pwm_chips, pos);
1309}
1310
1311static void pwm_seq_stop(struct seq_file *s, void *v)
1312{
1313 mutex_unlock(&pwm_lock);
1314}
1315
1316static int pwm_seq_show(struct seq_file *s, void *v)
1317{
1318 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1319
1320 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1321 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1322 dev_name(chip->dev), chip->npwm,
1323 (chip->npwm != 1) ? "s" : "");
1324
1325 pwm_dbg_show(chip, s);
1326
1327 return 0;
1328}
1329
1330static const struct seq_operations pwm_seq_ops = {
1331 .start = pwm_seq_start,
1332 .next = pwm_seq_next,
1333 .stop = pwm_seq_stop,
1334 .show = pwm_seq_show,
1335};
1336
1337static int pwm_seq_open(struct inode *inode, struct file *file)
1338{
1339 return seq_open(file, &pwm_seq_ops);
1340}
1341
1342static const struct file_operations pwm_debugfs_ops = {
1343 .owner = THIS_MODULE,
1344 .open = pwm_seq_open,
1345 .read = seq_read,
1346 .llseek = seq_lseek,
1347 .release = seq_release,
1348};
1349
1350static int __init pwm_debugfs_init(void)
1351{
1352 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
1353 &pwm_debugfs_ops);
1354
1355 return 0;
1356}
1357subsys_initcall(pwm_debugfs_init);
1358#endif /* CONFIG_DEBUG_FS */
1/*
2 * Generic pwmlib implementation
3 *
4 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
5 * Copyright (C) 2011-2012 Avionic Design GmbH
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2, or (at your option)
10 * any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; see the file COPYING. If not, write to
19 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include <linux/module.h>
23#include <linux/pwm.h>
24#include <linux/radix-tree.h>
25#include <linux/list.h>
26#include <linux/mutex.h>
27#include <linux/err.h>
28#include <linux/slab.h>
29#include <linux/device.h>
30#include <linux/debugfs.h>
31#include <linux/seq_file.h>
32
33#include <dt-bindings/pwm/pwm.h>
34
35#define MAX_PWMS 1024
36
37static DEFINE_MUTEX(pwm_lookup_lock);
38static LIST_HEAD(pwm_lookup_list);
39static DEFINE_MUTEX(pwm_lock);
40static LIST_HEAD(pwm_chips);
41static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
42static RADIX_TREE(pwm_tree, GFP_KERNEL);
43
44static struct pwm_device *pwm_to_device(unsigned int pwm)
45{
46 return radix_tree_lookup(&pwm_tree, pwm);
47}
48
49static int alloc_pwms(int pwm, unsigned int count)
50{
51 unsigned int from = 0;
52 unsigned int start;
53
54 if (pwm >= MAX_PWMS)
55 return -EINVAL;
56
57 if (pwm >= 0)
58 from = pwm;
59
60 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
61 count, 0);
62
63 if (pwm >= 0 && start != pwm)
64 return -EEXIST;
65
66 if (start + count > MAX_PWMS)
67 return -ENOSPC;
68
69 return start;
70}
71
72static void free_pwms(struct pwm_chip *chip)
73{
74 unsigned int i;
75
76 for (i = 0; i < chip->npwm; i++) {
77 struct pwm_device *pwm = &chip->pwms[i];
78
79 radix_tree_delete(&pwm_tree, pwm->pwm);
80 }
81
82 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
83
84 kfree(chip->pwms);
85 chip->pwms = NULL;
86}
87
88static struct pwm_chip *pwmchip_find_by_name(const char *name)
89{
90 struct pwm_chip *chip;
91
92 if (!name)
93 return NULL;
94
95 mutex_lock(&pwm_lock);
96
97 list_for_each_entry(chip, &pwm_chips, list) {
98 const char *chip_name = dev_name(chip->dev);
99
100 if (chip_name && strcmp(chip_name, name) == 0) {
101 mutex_unlock(&pwm_lock);
102 return chip;
103 }
104 }
105
106 mutex_unlock(&pwm_lock);
107
108 return NULL;
109}
110
111static int pwm_device_request(struct pwm_device *pwm, const char *label)
112{
113 int err;
114
115 if (test_bit(PWMF_REQUESTED, &pwm->flags))
116 return -EBUSY;
117
118 if (!try_module_get(pwm->chip->ops->owner))
119 return -ENODEV;
120
121 if (pwm->chip->ops->request) {
122 err = pwm->chip->ops->request(pwm->chip, pwm);
123 if (err) {
124 module_put(pwm->chip->ops->owner);
125 return err;
126 }
127 }
128
129 set_bit(PWMF_REQUESTED, &pwm->flags);
130 pwm->label = label;
131
132 return 0;
133}
134
135struct pwm_device *
136of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
137{
138 struct pwm_device *pwm;
139
140 /* check, whether the driver supports a third cell for flags */
141 if (pc->of_pwm_n_cells < 3)
142 return ERR_PTR(-EINVAL);
143
144 /* flags in the third cell are optional */
145 if (args->args_count < 2)
146 return ERR_PTR(-EINVAL);
147
148 if (args->args[0] >= pc->npwm)
149 return ERR_PTR(-EINVAL);
150
151 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
152 if (IS_ERR(pwm))
153 return pwm;
154
155 pwm->args.period = args->args[1];
156 pwm->args.polarity = PWM_POLARITY_NORMAL;
157
158 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
159 pwm->args.polarity = PWM_POLARITY_INVERSED;
160
161 return pwm;
162}
163EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
164
165static struct pwm_device *
166of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
167{
168 struct pwm_device *pwm;
169
170 /* sanity check driver support */
171 if (pc->of_pwm_n_cells < 2)
172 return ERR_PTR(-EINVAL);
173
174 /* all cells are required */
175 if (args->args_count != pc->of_pwm_n_cells)
176 return ERR_PTR(-EINVAL);
177
178 if (args->args[0] >= pc->npwm)
179 return ERR_PTR(-EINVAL);
180
181 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
182 if (IS_ERR(pwm))
183 return pwm;
184
185 pwm->args.period = args->args[1];
186
187 return pwm;
188}
189
190static void of_pwmchip_add(struct pwm_chip *chip)
191{
192 if (!chip->dev || !chip->dev->of_node)
193 return;
194
195 if (!chip->of_xlate) {
196 chip->of_xlate = of_pwm_simple_xlate;
197 chip->of_pwm_n_cells = 2;
198 }
199
200 of_node_get(chip->dev->of_node);
201}
202
203static void of_pwmchip_remove(struct pwm_chip *chip)
204{
205 if (chip->dev)
206 of_node_put(chip->dev->of_node);
207}
208
209/**
210 * pwm_set_chip_data() - set private chip data for a PWM
211 * @pwm: PWM device
212 * @data: pointer to chip-specific data
213 *
214 * Returns: 0 on success or a negative error code on failure.
215 */
216int pwm_set_chip_data(struct pwm_device *pwm, void *data)
217{
218 if (!pwm)
219 return -EINVAL;
220
221 pwm->chip_data = data;
222
223 return 0;
224}
225EXPORT_SYMBOL_GPL(pwm_set_chip_data);
226
227/**
228 * pwm_get_chip_data() - get private chip data for a PWM
229 * @pwm: PWM device
230 *
231 * Returns: A pointer to the chip-private data for the PWM device.
232 */
233void *pwm_get_chip_data(struct pwm_device *pwm)
234{
235 return pwm ? pwm->chip_data : NULL;
236}
237EXPORT_SYMBOL_GPL(pwm_get_chip_data);
238
239static bool pwm_ops_check(const struct pwm_ops *ops)
240{
241 /* driver supports legacy, non-atomic operation */
242 if (ops->config && ops->enable && ops->disable)
243 return true;
244
245 /* driver supports atomic operation */
246 if (ops->apply)
247 return true;
248
249 return false;
250}
251
252/**
253 * pwmchip_add_with_polarity() - register a new PWM chip
254 * @chip: the PWM chip to add
255 * @polarity: initial polarity of PWM channels
256 *
257 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
258 * will be used. The initial polarity for all channels is specified by the
259 * @polarity parameter.
260 *
261 * Returns: 0 on success or a negative error code on failure.
262 */
263int pwmchip_add_with_polarity(struct pwm_chip *chip,
264 enum pwm_polarity polarity)
265{
266 struct pwm_device *pwm;
267 unsigned int i;
268 int ret;
269
270 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
271 return -EINVAL;
272
273 if (!pwm_ops_check(chip->ops))
274 return -EINVAL;
275
276 mutex_lock(&pwm_lock);
277
278 ret = alloc_pwms(chip->base, chip->npwm);
279 if (ret < 0)
280 goto out;
281
282 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
283 if (!chip->pwms) {
284 ret = -ENOMEM;
285 goto out;
286 }
287
288 chip->base = ret;
289
290 for (i = 0; i < chip->npwm; i++) {
291 pwm = &chip->pwms[i];
292
293 pwm->chip = chip;
294 pwm->pwm = chip->base + i;
295 pwm->hwpwm = i;
296 pwm->state.polarity = polarity;
297
298 if (chip->ops->get_state)
299 chip->ops->get_state(chip, pwm, &pwm->state);
300
301 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
302 }
303
304 bitmap_set(allocated_pwms, chip->base, chip->npwm);
305
306 INIT_LIST_HEAD(&chip->list);
307 list_add(&chip->list, &pwm_chips);
308
309 ret = 0;
310
311 if (IS_ENABLED(CONFIG_OF))
312 of_pwmchip_add(chip);
313
314 pwmchip_sysfs_export(chip);
315
316out:
317 mutex_unlock(&pwm_lock);
318 return ret;
319}
320EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity);
321
322/**
323 * pwmchip_add() - register a new PWM chip
324 * @chip: the PWM chip to add
325 *
326 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
327 * will be used. The initial polarity for all channels is normal.
328 *
329 * Returns: 0 on success or a negative error code on failure.
330 */
331int pwmchip_add(struct pwm_chip *chip)
332{
333 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
334}
335EXPORT_SYMBOL_GPL(pwmchip_add);
336
337/**
338 * pwmchip_remove() - remove a PWM chip
339 * @chip: the PWM chip to remove
340 *
341 * Removes a PWM chip. This function may return busy if the PWM chip provides
342 * a PWM device that is still requested.
343 *
344 * Returns: 0 on success or a negative error code on failure.
345 */
346int pwmchip_remove(struct pwm_chip *chip)
347{
348 unsigned int i;
349 int ret = 0;
350
351 pwmchip_sysfs_unexport_children(chip);
352
353 mutex_lock(&pwm_lock);
354
355 for (i = 0; i < chip->npwm; i++) {
356 struct pwm_device *pwm = &chip->pwms[i];
357
358 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
359 ret = -EBUSY;
360 goto out;
361 }
362 }
363
364 list_del_init(&chip->list);
365
366 if (IS_ENABLED(CONFIG_OF))
367 of_pwmchip_remove(chip);
368
369 free_pwms(chip);
370
371 pwmchip_sysfs_unexport(chip);
372
373out:
374 mutex_unlock(&pwm_lock);
375 return ret;
376}
377EXPORT_SYMBOL_GPL(pwmchip_remove);
378
379/**
380 * pwm_request() - request a PWM device
381 * @pwm: global PWM device index
382 * @label: PWM device label
383 *
384 * This function is deprecated, use pwm_get() instead.
385 *
386 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
387 * failure.
388 */
389struct pwm_device *pwm_request(int pwm, const char *label)
390{
391 struct pwm_device *dev;
392 int err;
393
394 if (pwm < 0 || pwm >= MAX_PWMS)
395 return ERR_PTR(-EINVAL);
396
397 mutex_lock(&pwm_lock);
398
399 dev = pwm_to_device(pwm);
400 if (!dev) {
401 dev = ERR_PTR(-EPROBE_DEFER);
402 goto out;
403 }
404
405 err = pwm_device_request(dev, label);
406 if (err < 0)
407 dev = ERR_PTR(err);
408
409out:
410 mutex_unlock(&pwm_lock);
411
412 return dev;
413}
414EXPORT_SYMBOL_GPL(pwm_request);
415
416/**
417 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
418 * @chip: PWM chip
419 * @index: per-chip index of the PWM to request
420 * @label: a literal description string of this PWM
421 *
422 * Returns: A pointer to the PWM device at the given index of the given PWM
423 * chip. A negative error code is returned if the index is not valid for the
424 * specified PWM chip or if the PWM device cannot be requested.
425 */
426struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
427 unsigned int index,
428 const char *label)
429{
430 struct pwm_device *pwm;
431 int err;
432
433 if (!chip || index >= chip->npwm)
434 return ERR_PTR(-EINVAL);
435
436 mutex_lock(&pwm_lock);
437 pwm = &chip->pwms[index];
438
439 err = pwm_device_request(pwm, label);
440 if (err < 0)
441 pwm = ERR_PTR(err);
442
443 mutex_unlock(&pwm_lock);
444 return pwm;
445}
446EXPORT_SYMBOL_GPL(pwm_request_from_chip);
447
448/**
449 * pwm_free() - free a PWM device
450 * @pwm: PWM device
451 *
452 * This function is deprecated, use pwm_put() instead.
453 */
454void pwm_free(struct pwm_device *pwm)
455{
456 pwm_put(pwm);
457}
458EXPORT_SYMBOL_GPL(pwm_free);
459
460/**
461 * pwm_apply_state() - atomically apply a new state to a PWM device
462 * @pwm: PWM device
463 * @state: new state to apply. This can be adjusted by the PWM driver
464 * if the requested config is not achievable, for example,
465 * ->duty_cycle and ->period might be approximated.
466 */
467int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state)
468{
469 int err;
470
471 if (!pwm || !state || !state->period ||
472 state->duty_cycle > state->period)
473 return -EINVAL;
474
475 if (!memcmp(state, &pwm->state, sizeof(*state)))
476 return 0;
477
478 if (pwm->chip->ops->apply) {
479 err = pwm->chip->ops->apply(pwm->chip, pwm, state);
480 if (err)
481 return err;
482
483 pwm->state = *state;
484 } else {
485 /*
486 * FIXME: restore the initial state in case of error.
487 */
488 if (state->polarity != pwm->state.polarity) {
489 if (!pwm->chip->ops->set_polarity)
490 return -ENOTSUPP;
491
492 /*
493 * Changing the polarity of a running PWM is
494 * only allowed when the PWM driver implements
495 * ->apply().
496 */
497 if (pwm->state.enabled) {
498 pwm->chip->ops->disable(pwm->chip, pwm);
499 pwm->state.enabled = false;
500 }
501
502 err = pwm->chip->ops->set_polarity(pwm->chip, pwm,
503 state->polarity);
504 if (err)
505 return err;
506
507 pwm->state.polarity = state->polarity;
508 }
509
510 if (state->period != pwm->state.period ||
511 state->duty_cycle != pwm->state.duty_cycle) {
512 err = pwm->chip->ops->config(pwm->chip, pwm,
513 state->duty_cycle,
514 state->period);
515 if (err)
516 return err;
517
518 pwm->state.duty_cycle = state->duty_cycle;
519 pwm->state.period = state->period;
520 }
521
522 if (state->enabled != pwm->state.enabled) {
523 if (state->enabled) {
524 err = pwm->chip->ops->enable(pwm->chip, pwm);
525 if (err)
526 return err;
527 } else {
528 pwm->chip->ops->disable(pwm->chip, pwm);
529 }
530
531 pwm->state.enabled = state->enabled;
532 }
533 }
534
535 return 0;
536}
537EXPORT_SYMBOL_GPL(pwm_apply_state);
538
539/**
540 * pwm_capture() - capture and report a PWM signal
541 * @pwm: PWM device
542 * @result: structure to fill with capture result
543 * @timeout: time to wait, in milliseconds, before giving up on capture
544 *
545 * Returns: 0 on success or a negative error code on failure.
546 */
547int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
548 unsigned long timeout)
549{
550 int err;
551
552 if (!pwm || !pwm->chip->ops)
553 return -EINVAL;
554
555 if (!pwm->chip->ops->capture)
556 return -ENOSYS;
557
558 mutex_lock(&pwm_lock);
559 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
560 mutex_unlock(&pwm_lock);
561
562 return err;
563}
564EXPORT_SYMBOL_GPL(pwm_capture);
565
566/**
567 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
568 * @pwm: PWM device
569 *
570 * This function will adjust the PWM config to the PWM arguments provided
571 * by the DT or PWM lookup table. This is particularly useful to adapt
572 * the bootloader config to the Linux one.
573 */
574int pwm_adjust_config(struct pwm_device *pwm)
575{
576 struct pwm_state state;
577 struct pwm_args pargs;
578
579 pwm_get_args(pwm, &pargs);
580 pwm_get_state(pwm, &state);
581
582 /*
583 * If the current period is zero it means that either the PWM driver
584 * does not support initial state retrieval or the PWM has not yet
585 * been configured.
586 *
587 * In either case, we setup the new period and polarity, and assign a
588 * duty cycle of 0.
589 */
590 if (!state.period) {
591 state.duty_cycle = 0;
592 state.period = pargs.period;
593 state.polarity = pargs.polarity;
594
595 return pwm_apply_state(pwm, &state);
596 }
597
598 /*
599 * Adjust the PWM duty cycle/period based on the period value provided
600 * in PWM args.
601 */
602 if (pargs.period != state.period) {
603 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
604
605 do_div(dutycycle, state.period);
606 state.duty_cycle = dutycycle;
607 state.period = pargs.period;
608 }
609
610 /*
611 * If the polarity changed, we should also change the duty cycle.
612 */
613 if (pargs.polarity != state.polarity) {
614 state.polarity = pargs.polarity;
615 state.duty_cycle = state.period - state.duty_cycle;
616 }
617
618 return pwm_apply_state(pwm, &state);
619}
620EXPORT_SYMBOL_GPL(pwm_adjust_config);
621
622static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
623{
624 struct pwm_chip *chip;
625
626 mutex_lock(&pwm_lock);
627
628 list_for_each_entry(chip, &pwm_chips, list)
629 if (chip->dev && chip->dev->of_node == np) {
630 mutex_unlock(&pwm_lock);
631 return chip;
632 }
633
634 mutex_unlock(&pwm_lock);
635
636 return ERR_PTR(-EPROBE_DEFER);
637}
638
639/**
640 * of_pwm_get() - request a PWM via the PWM framework
641 * @np: device node to get the PWM from
642 * @con_id: consumer name
643 *
644 * Returns the PWM device parsed from the phandle and index specified in the
645 * "pwms" property of a device tree node or a negative error-code on failure.
646 * Values parsed from the device tree are stored in the returned PWM device
647 * object.
648 *
649 * If con_id is NULL, the first PWM device listed in the "pwms" property will
650 * be requested. Otherwise the "pwm-names" property is used to do a reverse
651 * lookup of the PWM index. This also means that the "pwm-names" property
652 * becomes mandatory for devices that look up the PWM device via the con_id
653 * parameter.
654 *
655 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
656 * error code on failure.
657 */
658struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
659{
660 struct pwm_device *pwm = NULL;
661 struct of_phandle_args args;
662 struct pwm_chip *pc;
663 int index = 0;
664 int err;
665
666 if (con_id) {
667 index = of_property_match_string(np, "pwm-names", con_id);
668 if (index < 0)
669 return ERR_PTR(index);
670 }
671
672 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
673 &args);
674 if (err) {
675 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
676 return ERR_PTR(err);
677 }
678
679 pc = of_node_to_pwmchip(args.np);
680 if (IS_ERR(pc)) {
681 if (PTR_ERR(pc) != -EPROBE_DEFER)
682 pr_err("%s(): PWM chip not found\n", __func__);
683
684 pwm = ERR_CAST(pc);
685 goto put;
686 }
687
688 pwm = pc->of_xlate(pc, &args);
689 if (IS_ERR(pwm))
690 goto put;
691
692 /*
693 * If a consumer name was not given, try to look it up from the
694 * "pwm-names" property if it exists. Otherwise use the name of
695 * the user device node.
696 */
697 if (!con_id) {
698 err = of_property_read_string_index(np, "pwm-names", index,
699 &con_id);
700 if (err < 0)
701 con_id = np->name;
702 }
703
704 pwm->label = con_id;
705
706put:
707 of_node_put(args.np);
708
709 return pwm;
710}
711EXPORT_SYMBOL_GPL(of_pwm_get);
712
713/**
714 * pwm_add_table() - register PWM device consumers
715 * @table: array of consumers to register
716 * @num: number of consumers in table
717 */
718void pwm_add_table(struct pwm_lookup *table, size_t num)
719{
720 mutex_lock(&pwm_lookup_lock);
721
722 while (num--) {
723 list_add_tail(&table->list, &pwm_lookup_list);
724 table++;
725 }
726
727 mutex_unlock(&pwm_lookup_lock);
728}
729
730/**
731 * pwm_remove_table() - unregister PWM device consumers
732 * @table: array of consumers to unregister
733 * @num: number of consumers in table
734 */
735void pwm_remove_table(struct pwm_lookup *table, size_t num)
736{
737 mutex_lock(&pwm_lookup_lock);
738
739 while (num--) {
740 list_del(&table->list);
741 table++;
742 }
743
744 mutex_unlock(&pwm_lookup_lock);
745}
746
747/**
748 * pwm_get() - look up and request a PWM device
749 * @dev: device for PWM consumer
750 * @con_id: consumer name
751 *
752 * Lookup is first attempted using DT. If the device was not instantiated from
753 * a device tree, a PWM chip and a relative index is looked up via a table
754 * supplied by board setup code (see pwm_add_table()).
755 *
756 * Once a PWM chip has been found the specified PWM device will be requested
757 * and is ready to be used.
758 *
759 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
760 * error code on failure.
761 */
762struct pwm_device *pwm_get(struct device *dev, const char *con_id)
763{
764 const char *dev_id = dev ? dev_name(dev) : NULL;
765 struct pwm_device *pwm;
766 struct pwm_chip *chip;
767 unsigned int best = 0;
768 struct pwm_lookup *p, *chosen = NULL;
769 unsigned int match;
770 int err;
771
772 /* look up via DT first */
773 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
774 return of_pwm_get(dev->of_node, con_id);
775
776 /*
777 * We look up the provider in the static table typically provided by
778 * board setup code. We first try to lookup the consumer device by
779 * name. If the consumer device was passed in as NULL or if no match
780 * was found, we try to find the consumer by directly looking it up
781 * by name.
782 *
783 * If a match is found, the provider PWM chip is looked up by name
784 * and a PWM device is requested using the PWM device per-chip index.
785 *
786 * The lookup algorithm was shamelessly taken from the clock
787 * framework:
788 *
789 * We do slightly fuzzy matching here:
790 * An entry with a NULL ID is assumed to be a wildcard.
791 * If an entry has a device ID, it must match
792 * If an entry has a connection ID, it must match
793 * Then we take the most specific entry - with the following order
794 * of precedence: dev+con > dev only > con only.
795 */
796 mutex_lock(&pwm_lookup_lock);
797
798 list_for_each_entry(p, &pwm_lookup_list, list) {
799 match = 0;
800
801 if (p->dev_id) {
802 if (!dev_id || strcmp(p->dev_id, dev_id))
803 continue;
804
805 match += 2;
806 }
807
808 if (p->con_id) {
809 if (!con_id || strcmp(p->con_id, con_id))
810 continue;
811
812 match += 1;
813 }
814
815 if (match > best) {
816 chosen = p;
817
818 if (match != 3)
819 best = match;
820 else
821 break;
822 }
823 }
824
825 mutex_unlock(&pwm_lookup_lock);
826
827 if (!chosen)
828 return ERR_PTR(-ENODEV);
829
830 chip = pwmchip_find_by_name(chosen->provider);
831
832 /*
833 * If the lookup entry specifies a module, load the module and retry
834 * the PWM chip lookup. This can be used to work around driver load
835 * ordering issues if driver's can't be made to properly support the
836 * deferred probe mechanism.
837 */
838 if (!chip && chosen->module) {
839 err = request_module(chosen->module);
840 if (err == 0)
841 chip = pwmchip_find_by_name(chosen->provider);
842 }
843
844 if (!chip)
845 return ERR_PTR(-EPROBE_DEFER);
846
847 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
848 if (IS_ERR(pwm))
849 return pwm;
850
851 pwm->args.period = chosen->period;
852 pwm->args.polarity = chosen->polarity;
853
854 return pwm;
855}
856EXPORT_SYMBOL_GPL(pwm_get);
857
858/**
859 * pwm_put() - release a PWM device
860 * @pwm: PWM device
861 */
862void pwm_put(struct pwm_device *pwm)
863{
864 if (!pwm)
865 return;
866
867 mutex_lock(&pwm_lock);
868
869 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
870 pr_warn("PWM device already freed\n");
871 goto out;
872 }
873
874 if (pwm->chip->ops->free)
875 pwm->chip->ops->free(pwm->chip, pwm);
876
877 pwm->label = NULL;
878
879 module_put(pwm->chip->ops->owner);
880out:
881 mutex_unlock(&pwm_lock);
882}
883EXPORT_SYMBOL_GPL(pwm_put);
884
885static void devm_pwm_release(struct device *dev, void *res)
886{
887 pwm_put(*(struct pwm_device **)res);
888}
889
890/**
891 * devm_pwm_get() - resource managed pwm_get()
892 * @dev: device for PWM consumer
893 * @con_id: consumer name
894 *
895 * This function performs like pwm_get() but the acquired PWM device will
896 * automatically be released on driver detach.
897 *
898 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
899 * error code on failure.
900 */
901struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
902{
903 struct pwm_device **ptr, *pwm;
904
905 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
906 if (!ptr)
907 return ERR_PTR(-ENOMEM);
908
909 pwm = pwm_get(dev, con_id);
910 if (!IS_ERR(pwm)) {
911 *ptr = pwm;
912 devres_add(dev, ptr);
913 } else {
914 devres_free(ptr);
915 }
916
917 return pwm;
918}
919EXPORT_SYMBOL_GPL(devm_pwm_get);
920
921/**
922 * devm_of_pwm_get() - resource managed of_pwm_get()
923 * @dev: device for PWM consumer
924 * @np: device node to get the PWM from
925 * @con_id: consumer name
926 *
927 * This function performs like of_pwm_get() but the acquired PWM device will
928 * automatically be released on driver detach.
929 *
930 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
931 * error code on failure.
932 */
933struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
934 const char *con_id)
935{
936 struct pwm_device **ptr, *pwm;
937
938 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
939 if (!ptr)
940 return ERR_PTR(-ENOMEM);
941
942 pwm = of_pwm_get(np, con_id);
943 if (!IS_ERR(pwm)) {
944 *ptr = pwm;
945 devres_add(dev, ptr);
946 } else {
947 devres_free(ptr);
948 }
949
950 return pwm;
951}
952EXPORT_SYMBOL_GPL(devm_of_pwm_get);
953
954static int devm_pwm_match(struct device *dev, void *res, void *data)
955{
956 struct pwm_device **p = res;
957
958 if (WARN_ON(!p || !*p))
959 return 0;
960
961 return *p == data;
962}
963
964/**
965 * devm_pwm_put() - resource managed pwm_put()
966 * @dev: device for PWM consumer
967 * @pwm: PWM device
968 *
969 * Release a PWM previously allocated using devm_pwm_get(). Calling this
970 * function is usually not needed because devm-allocated resources are
971 * automatically released on driver detach.
972 */
973void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
974{
975 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
976}
977EXPORT_SYMBOL_GPL(devm_pwm_put);
978
979#ifdef CONFIG_DEBUG_FS
980static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
981{
982 unsigned int i;
983
984 for (i = 0; i < chip->npwm; i++) {
985 struct pwm_device *pwm = &chip->pwms[i];
986 struct pwm_state state;
987
988 pwm_get_state(pwm, &state);
989
990 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
991
992 if (test_bit(PWMF_REQUESTED, &pwm->flags))
993 seq_puts(s, " requested");
994
995 if (state.enabled)
996 seq_puts(s, " enabled");
997
998 seq_printf(s, " period: %u ns", state.period);
999 seq_printf(s, " duty: %u ns", state.duty_cycle);
1000 seq_printf(s, " polarity: %s",
1001 state.polarity ? "inverse" : "normal");
1002
1003 seq_puts(s, "\n");
1004 }
1005}
1006
1007static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1008{
1009 mutex_lock(&pwm_lock);
1010 s->private = "";
1011
1012 return seq_list_start(&pwm_chips, *pos);
1013}
1014
1015static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1016{
1017 s->private = "\n";
1018
1019 return seq_list_next(v, &pwm_chips, pos);
1020}
1021
1022static void pwm_seq_stop(struct seq_file *s, void *v)
1023{
1024 mutex_unlock(&pwm_lock);
1025}
1026
1027static int pwm_seq_show(struct seq_file *s, void *v)
1028{
1029 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1030
1031 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1032 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1033 dev_name(chip->dev), chip->npwm,
1034 (chip->npwm != 1) ? "s" : "");
1035
1036 if (chip->ops->dbg_show)
1037 chip->ops->dbg_show(chip, s);
1038 else
1039 pwm_dbg_show(chip, s);
1040
1041 return 0;
1042}
1043
1044static const struct seq_operations pwm_seq_ops = {
1045 .start = pwm_seq_start,
1046 .next = pwm_seq_next,
1047 .stop = pwm_seq_stop,
1048 .show = pwm_seq_show,
1049};
1050
1051static int pwm_seq_open(struct inode *inode, struct file *file)
1052{
1053 return seq_open(file, &pwm_seq_ops);
1054}
1055
1056static const struct file_operations pwm_debugfs_ops = {
1057 .owner = THIS_MODULE,
1058 .open = pwm_seq_open,
1059 .read = seq_read,
1060 .llseek = seq_lseek,
1061 .release = seq_release,
1062};
1063
1064static int __init pwm_debugfs_init(void)
1065{
1066 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
1067 &pwm_debugfs_ops);
1068
1069 return 0;
1070}
1071subsys_initcall(pwm_debugfs_init);
1072#endif /* CONFIG_DEBUG_FS */