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