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