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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Generic pwmlib implementation
4 *
5 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
6 * Copyright (C) 2011-2012 Avionic Design GmbH
7 */
8
9#include <linux/acpi.h>
10#include <linux/module.h>
11#include <linux/pwm.h>
12#include <linux/radix-tree.h>
13#include <linux/list.h>
14#include <linux/mutex.h>
15#include <linux/err.h>
16#include <linux/slab.h>
17#include <linux/device.h>
18#include <linux/debugfs.h>
19#include <linux/seq_file.h>
20
21#include <dt-bindings/pwm/pwm.h>
22
23#define CREATE_TRACE_POINTS
24#include <trace/events/pwm.h>
25
26#define MAX_PWMS 1024
27
28static DEFINE_MUTEX(pwm_lookup_lock);
29static LIST_HEAD(pwm_lookup_list);
30static DEFINE_MUTEX(pwm_lock);
31static LIST_HEAD(pwm_chips);
32static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
33static RADIX_TREE(pwm_tree, GFP_KERNEL);
34
35static struct pwm_device *pwm_to_device(unsigned int pwm)
36{
37 return radix_tree_lookup(&pwm_tree, pwm);
38}
39
40static int alloc_pwms(int pwm, unsigned int count)
41{
42 unsigned int from = 0;
43 unsigned int start;
44
45 if (pwm >= MAX_PWMS)
46 return -EINVAL;
47
48 if (pwm >= 0)
49 from = pwm;
50
51 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
52 count, 0);
53
54 if (pwm >= 0 && start != pwm)
55 return -EEXIST;
56
57 if (start + count > MAX_PWMS)
58 return -ENOSPC;
59
60 return start;
61}
62
63static void free_pwms(struct pwm_chip *chip)
64{
65 unsigned int i;
66
67 for (i = 0; i < chip->npwm; i++) {
68 struct pwm_device *pwm = &chip->pwms[i];
69
70 radix_tree_delete(&pwm_tree, pwm->pwm);
71 }
72
73 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
74
75 kfree(chip->pwms);
76 chip->pwms = NULL;
77}
78
79static struct pwm_chip *pwmchip_find_by_name(const char *name)
80{
81 struct pwm_chip *chip;
82
83 if (!name)
84 return NULL;
85
86 mutex_lock(&pwm_lock);
87
88 list_for_each_entry(chip, &pwm_chips, list) {
89 const char *chip_name = dev_name(chip->dev);
90
91 if (chip_name && strcmp(chip_name, name) == 0) {
92 mutex_unlock(&pwm_lock);
93 return chip;
94 }
95 }
96
97 mutex_unlock(&pwm_lock);
98
99 return NULL;
100}
101
102static int pwm_device_request(struct pwm_device *pwm, const char *label)
103{
104 int err;
105
106 if (test_bit(PWMF_REQUESTED, &pwm->flags))
107 return -EBUSY;
108
109 if (!try_module_get(pwm->chip->ops->owner))
110 return -ENODEV;
111
112 if (pwm->chip->ops->request) {
113 err = pwm->chip->ops->request(pwm->chip, pwm);
114 if (err) {
115 module_put(pwm->chip->ops->owner);
116 return err;
117 }
118 }
119
120 if (pwm->chip->ops->get_state) {
121 pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state);
122 trace_pwm_get(pwm, &pwm->state);
123
124 if (IS_ENABLED(CONFIG_PWM_DEBUG))
125 pwm->last = pwm->state;
126 }
127
128 set_bit(PWMF_REQUESTED, &pwm->flags);
129 pwm->label = label;
130
131 return 0;
132}
133
134struct pwm_device *
135of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
136{
137 struct pwm_device *pwm;
138
139 /* check, whether the driver supports a third cell for flags */
140 if (pc->of_pwm_n_cells < 3)
141 return ERR_PTR(-EINVAL);
142
143 /* flags in the third cell are optional */
144 if (args->args_count < 2)
145 return ERR_PTR(-EINVAL);
146
147 if (args->args[0] >= pc->npwm)
148 return ERR_PTR(-EINVAL);
149
150 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
151 if (IS_ERR(pwm))
152 return pwm;
153
154 pwm->args.period = args->args[1];
155 pwm->args.polarity = PWM_POLARITY_NORMAL;
156
157 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
158 pwm->args.polarity = PWM_POLARITY_INVERSED;
159
160 return pwm;
161}
162EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
163
164static struct pwm_device *
165of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
166{
167 struct pwm_device *pwm;
168
169 /* sanity check driver support */
170 if (pc->of_pwm_n_cells < 2)
171 return ERR_PTR(-EINVAL);
172
173 /* all cells are required */
174 if (args->args_count != pc->of_pwm_n_cells)
175 return ERR_PTR(-EINVAL);
176
177 if (args->args[0] >= pc->npwm)
178 return ERR_PTR(-EINVAL);
179
180 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
181 if (IS_ERR(pwm))
182 return pwm;
183
184 pwm->args.period = args->args[1];
185
186 return pwm;
187}
188
189static void of_pwmchip_add(struct pwm_chip *chip)
190{
191 if (!chip->dev || !chip->dev->of_node)
192 return;
193
194 if (!chip->of_xlate) {
195 chip->of_xlate = of_pwm_simple_xlate;
196 chip->of_pwm_n_cells = 2;
197 }
198
199 of_node_get(chip->dev->of_node);
200}
201
202static void of_pwmchip_remove(struct pwm_chip *chip)
203{
204 if (chip->dev)
205 of_node_put(chip->dev->of_node);
206}
207
208/**
209 * pwm_set_chip_data() - set private chip data for a PWM
210 * @pwm: PWM device
211 * @data: pointer to chip-specific data
212 *
213 * Returns: 0 on success or a negative error code on failure.
214 */
215int pwm_set_chip_data(struct pwm_device *pwm, void *data)
216{
217 if (!pwm)
218 return -EINVAL;
219
220 pwm->chip_data = data;
221
222 return 0;
223}
224EXPORT_SYMBOL_GPL(pwm_set_chip_data);
225
226/**
227 * pwm_get_chip_data() - get private chip data for a PWM
228 * @pwm: PWM device
229 *
230 * Returns: A pointer to the chip-private data for the PWM device.
231 */
232void *pwm_get_chip_data(struct pwm_device *pwm)
233{
234 return pwm ? pwm->chip_data : NULL;
235}
236EXPORT_SYMBOL_GPL(pwm_get_chip_data);
237
238static bool pwm_ops_check(const struct pwm_chip *chip)
239{
240
241 const struct pwm_ops *ops = chip->ops;
242
243 /* driver supports legacy, non-atomic operation */
244 if (ops->config && ops->enable && ops->disable) {
245 if (IS_ENABLED(CONFIG_PWM_DEBUG))
246 dev_warn(chip->dev,
247 "Driver needs updating to atomic API\n");
248
249 return true;
250 }
251
252 if (!ops->apply)
253 return false;
254
255 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
256 dev_warn(chip->dev,
257 "Please implement the .get_state() callback\n");
258
259 return true;
260}
261
262/**
263 * pwmchip_add_with_polarity() - register a new PWM chip
264 * @chip: the PWM chip to add
265 * @polarity: initial polarity of PWM channels
266 *
267 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
268 * will be used. The initial polarity for all channels is specified by the
269 * @polarity parameter.
270 *
271 * Returns: 0 on success or a negative error code on failure.
272 */
273int pwmchip_add_with_polarity(struct pwm_chip *chip,
274 enum pwm_polarity polarity)
275{
276 struct pwm_device *pwm;
277 unsigned int i;
278 int ret;
279
280 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
281 return -EINVAL;
282
283 if (!pwm_ops_check(chip))
284 return -EINVAL;
285
286 mutex_lock(&pwm_lock);
287
288 ret = alloc_pwms(chip->base, chip->npwm);
289 if (ret < 0)
290 goto out;
291
292 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
293 if (!chip->pwms) {
294 ret = -ENOMEM;
295 goto out;
296 }
297
298 chip->base = ret;
299
300 for (i = 0; i < chip->npwm; i++) {
301 pwm = &chip->pwms[i];
302
303 pwm->chip = chip;
304 pwm->pwm = chip->base + i;
305 pwm->hwpwm = i;
306 pwm->state.polarity = polarity;
307
308 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
309 }
310
311 bitmap_set(allocated_pwms, chip->base, chip->npwm);
312
313 INIT_LIST_HEAD(&chip->list);
314 list_add(&chip->list, &pwm_chips);
315
316 ret = 0;
317
318 if (IS_ENABLED(CONFIG_OF))
319 of_pwmchip_add(chip);
320
321out:
322 mutex_unlock(&pwm_lock);
323
324 if (!ret)
325 pwmchip_sysfs_export(chip);
326
327 return ret;
328}
329EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity);
330
331/**
332 * pwmchip_add() - register a new PWM chip
333 * @chip: the PWM chip to add
334 *
335 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
336 * will be used. The initial polarity for all channels is normal.
337 *
338 * Returns: 0 on success or a negative error code on failure.
339 */
340int pwmchip_add(struct pwm_chip *chip)
341{
342 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
343}
344EXPORT_SYMBOL_GPL(pwmchip_add);
345
346/**
347 * pwmchip_remove() - remove a PWM chip
348 * @chip: the PWM chip to remove
349 *
350 * Removes a PWM chip. This function may return busy if the PWM chip provides
351 * a PWM device that is still requested.
352 *
353 * Returns: 0 on success or a negative error code on failure.
354 */
355int pwmchip_remove(struct pwm_chip *chip)
356{
357 unsigned int i;
358 int ret = 0;
359
360 pwmchip_sysfs_unexport(chip);
361
362 mutex_lock(&pwm_lock);
363
364 for (i = 0; i < chip->npwm; i++) {
365 struct pwm_device *pwm = &chip->pwms[i];
366
367 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
368 ret = -EBUSY;
369 goto out;
370 }
371 }
372
373 list_del_init(&chip->list);
374
375 if (IS_ENABLED(CONFIG_OF))
376 of_pwmchip_remove(chip);
377
378 free_pwms(chip);
379
380out:
381 mutex_unlock(&pwm_lock);
382 return ret;
383}
384EXPORT_SYMBOL_GPL(pwmchip_remove);
385
386/**
387 * pwm_request() - request a PWM device
388 * @pwm: global PWM device index
389 * @label: PWM device label
390 *
391 * This function is deprecated, use pwm_get() instead.
392 *
393 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
394 * failure.
395 */
396struct pwm_device *pwm_request(int pwm, const char *label)
397{
398 struct pwm_device *dev;
399 int err;
400
401 if (pwm < 0 || pwm >= MAX_PWMS)
402 return ERR_PTR(-EINVAL);
403
404 mutex_lock(&pwm_lock);
405
406 dev = pwm_to_device(pwm);
407 if (!dev) {
408 dev = ERR_PTR(-EPROBE_DEFER);
409 goto out;
410 }
411
412 err = pwm_device_request(dev, label);
413 if (err < 0)
414 dev = ERR_PTR(err);
415
416out:
417 mutex_unlock(&pwm_lock);
418
419 return dev;
420}
421EXPORT_SYMBOL_GPL(pwm_request);
422
423/**
424 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
425 * @chip: PWM chip
426 * @index: per-chip index of the PWM to request
427 * @label: a literal description string of this PWM
428 *
429 * Returns: A pointer to the PWM device at the given index of the given PWM
430 * chip. A negative error code is returned if the index is not valid for the
431 * specified PWM chip or if the PWM device cannot be requested.
432 */
433struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
434 unsigned int index,
435 const char *label)
436{
437 struct pwm_device *pwm;
438 int err;
439
440 if (!chip || index >= chip->npwm)
441 return ERR_PTR(-EINVAL);
442
443 mutex_lock(&pwm_lock);
444 pwm = &chip->pwms[index];
445
446 err = pwm_device_request(pwm, label);
447 if (err < 0)
448 pwm = ERR_PTR(err);
449
450 mutex_unlock(&pwm_lock);
451 return pwm;
452}
453EXPORT_SYMBOL_GPL(pwm_request_from_chip);
454
455/**
456 * pwm_free() - free a PWM device
457 * @pwm: PWM device
458 *
459 * This function is deprecated, use pwm_put() instead.
460 */
461void pwm_free(struct pwm_device *pwm)
462{
463 pwm_put(pwm);
464}
465EXPORT_SYMBOL_GPL(pwm_free);
466
467static void pwm_apply_state_debug(struct pwm_device *pwm,
468 const struct pwm_state *state)
469{
470 struct pwm_state *last = &pwm->last;
471 struct pwm_chip *chip = pwm->chip;
472 struct pwm_state s1, s2;
473 int err;
474
475 if (!IS_ENABLED(CONFIG_PWM_DEBUG))
476 return;
477
478 /* No reasonable diagnosis possible without .get_state() */
479 if (!chip->ops->get_state)
480 return;
481
482 /*
483 * *state was just applied. Read out the hardware state and do some
484 * checks.
485 */
486
487 chip->ops->get_state(chip, pwm, &s1);
488 trace_pwm_get(pwm, &s1);
489
490 /*
491 * The lowlevel driver either ignored .polarity (which is a bug) or as
492 * best effort inverted .polarity and fixed .duty_cycle respectively.
493 * Undo this inversion and fixup for further tests.
494 */
495 if (s1.enabled && s1.polarity != state->polarity) {
496 s2.polarity = state->polarity;
497 s2.duty_cycle = s1.period - s1.duty_cycle;
498 s2.period = s1.period;
499 s2.enabled = s1.enabled;
500 } else {
501 s2 = s1;
502 }
503
504 if (s2.polarity != state->polarity &&
505 state->duty_cycle < state->period)
506 dev_warn(chip->dev, ".apply ignored .polarity\n");
507
508 if (state->enabled &&
509 last->polarity == state->polarity &&
510 last->period > s2.period &&
511 last->period <= state->period)
512 dev_warn(chip->dev,
513 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
514 state->period, s2.period, last->period);
515
516 if (state->enabled && state->period < s2.period)
517 dev_warn(chip->dev,
518 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
519 state->period, s2.period);
520
521 if (state->enabled &&
522 last->polarity == state->polarity &&
523 last->period == s2.period &&
524 last->duty_cycle > s2.duty_cycle &&
525 last->duty_cycle <= state->duty_cycle)
526 dev_warn(chip->dev,
527 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
528 state->duty_cycle, state->period,
529 s2.duty_cycle, s2.period,
530 last->duty_cycle, last->period);
531
532 if (state->enabled && state->duty_cycle < s2.duty_cycle)
533 dev_warn(chip->dev,
534 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
535 state->duty_cycle, state->period,
536 s2.duty_cycle, s2.period);
537
538 if (!state->enabled && s2.enabled && s2.duty_cycle > 0)
539 dev_warn(chip->dev,
540 "requested disabled, but yielded enabled with duty > 0\n");
541
542 /* reapply the state that the driver reported being configured. */
543 err = chip->ops->apply(chip, pwm, &s1);
544 if (err) {
545 *last = s1;
546 dev_err(chip->dev, "failed to reapply current setting\n");
547 return;
548 }
549
550 trace_pwm_apply(pwm, &s1);
551
552 chip->ops->get_state(chip, pwm, last);
553 trace_pwm_get(pwm, last);
554
555 /* reapplication of the current state should give an exact match */
556 if (s1.enabled != last->enabled ||
557 s1.polarity != last->polarity ||
558 (s1.enabled && s1.period != last->period) ||
559 (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
560 dev_err(chip->dev,
561 ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
562 s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
563 last->enabled, last->polarity, last->duty_cycle,
564 last->period);
565 }
566}
567
568/**
569 * pwm_apply_state() - atomically apply a new state to a PWM device
570 * @pwm: PWM device
571 * @state: new state to apply
572 */
573int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
574{
575 struct pwm_chip *chip;
576 int err;
577
578 if (!pwm || !state || !state->period ||
579 state->duty_cycle > state->period)
580 return -EINVAL;
581
582 chip = pwm->chip;
583
584 if (state->period == pwm->state.period &&
585 state->duty_cycle == pwm->state.duty_cycle &&
586 state->polarity == pwm->state.polarity &&
587 state->enabled == pwm->state.enabled)
588 return 0;
589
590 if (chip->ops->apply) {
591 err = chip->ops->apply(chip, pwm, state);
592 if (err)
593 return err;
594
595 trace_pwm_apply(pwm, state);
596
597 pwm->state = *state;
598
599 /*
600 * only do this after pwm->state was applied as some
601 * implementations of .get_state depend on this
602 */
603 pwm_apply_state_debug(pwm, state);
604 } else {
605 /*
606 * FIXME: restore the initial state in case of error.
607 */
608 if (state->polarity != pwm->state.polarity) {
609 if (!chip->ops->set_polarity)
610 return -ENOTSUPP;
611
612 /*
613 * Changing the polarity of a running PWM is
614 * only allowed when the PWM driver implements
615 * ->apply().
616 */
617 if (pwm->state.enabled) {
618 chip->ops->disable(chip, pwm);
619 pwm->state.enabled = false;
620 }
621
622 err = chip->ops->set_polarity(chip, pwm,
623 state->polarity);
624 if (err)
625 return err;
626
627 pwm->state.polarity = state->polarity;
628 }
629
630 if (state->period != pwm->state.period ||
631 state->duty_cycle != pwm->state.duty_cycle) {
632 err = chip->ops->config(pwm->chip, pwm,
633 state->duty_cycle,
634 state->period);
635 if (err)
636 return err;
637
638 pwm->state.duty_cycle = state->duty_cycle;
639 pwm->state.period = state->period;
640 }
641
642 if (state->enabled != pwm->state.enabled) {
643 if (state->enabled) {
644 err = chip->ops->enable(chip, pwm);
645 if (err)
646 return err;
647 } else {
648 chip->ops->disable(chip, pwm);
649 }
650
651 pwm->state.enabled = state->enabled;
652 }
653 }
654
655 return 0;
656}
657EXPORT_SYMBOL_GPL(pwm_apply_state);
658
659/**
660 * pwm_capture() - capture and report a PWM signal
661 * @pwm: PWM device
662 * @result: structure to fill with capture result
663 * @timeout: time to wait, in milliseconds, before giving up on capture
664 *
665 * Returns: 0 on success or a negative error code on failure.
666 */
667int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
668 unsigned long timeout)
669{
670 int err;
671
672 if (!pwm || !pwm->chip->ops)
673 return -EINVAL;
674
675 if (!pwm->chip->ops->capture)
676 return -ENOSYS;
677
678 mutex_lock(&pwm_lock);
679 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
680 mutex_unlock(&pwm_lock);
681
682 return err;
683}
684EXPORT_SYMBOL_GPL(pwm_capture);
685
686/**
687 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
688 * @pwm: PWM device
689 *
690 * This function will adjust the PWM config to the PWM arguments provided
691 * by the DT or PWM lookup table. This is particularly useful to adapt
692 * the bootloader config to the Linux one.
693 */
694int pwm_adjust_config(struct pwm_device *pwm)
695{
696 struct pwm_state state;
697 struct pwm_args pargs;
698
699 pwm_get_args(pwm, &pargs);
700 pwm_get_state(pwm, &state);
701
702 /*
703 * If the current period is zero it means that either the PWM driver
704 * does not support initial state retrieval or the PWM has not yet
705 * been configured.
706 *
707 * In either case, we setup the new period and polarity, and assign a
708 * duty cycle of 0.
709 */
710 if (!state.period) {
711 state.duty_cycle = 0;
712 state.period = pargs.period;
713 state.polarity = pargs.polarity;
714
715 return pwm_apply_state(pwm, &state);
716 }
717
718 /*
719 * Adjust the PWM duty cycle/period based on the period value provided
720 * in PWM args.
721 */
722 if (pargs.period != state.period) {
723 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
724
725 do_div(dutycycle, state.period);
726 state.duty_cycle = dutycycle;
727 state.period = pargs.period;
728 }
729
730 /*
731 * If the polarity changed, we should also change the duty cycle.
732 */
733 if (pargs.polarity != state.polarity) {
734 state.polarity = pargs.polarity;
735 state.duty_cycle = state.period - state.duty_cycle;
736 }
737
738 return pwm_apply_state(pwm, &state);
739}
740EXPORT_SYMBOL_GPL(pwm_adjust_config);
741
742static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
743{
744 struct pwm_chip *chip;
745
746 mutex_lock(&pwm_lock);
747
748 list_for_each_entry(chip, &pwm_chips, list)
749 if (chip->dev && chip->dev->of_node == np) {
750 mutex_unlock(&pwm_lock);
751 return chip;
752 }
753
754 mutex_unlock(&pwm_lock);
755
756 return ERR_PTR(-EPROBE_DEFER);
757}
758
759static struct device_link *pwm_device_link_add(struct device *dev,
760 struct pwm_device *pwm)
761{
762 struct device_link *dl;
763
764 if (!dev) {
765 /*
766 * No device for the PWM consumer has been provided. It may
767 * impact the PM sequence ordering: the PWM supplier may get
768 * suspended before the consumer.
769 */
770 dev_warn(pwm->chip->dev,
771 "No consumer device specified to create a link to\n");
772 return NULL;
773 }
774
775 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
776 if (!dl) {
777 dev_err(dev, "failed to create device link to %s\n",
778 dev_name(pwm->chip->dev));
779 return ERR_PTR(-EINVAL);
780 }
781
782 return dl;
783}
784
785/**
786 * of_pwm_get() - request a PWM via the PWM framework
787 * @dev: device for PWM consumer
788 * @np: device node to get the PWM from
789 * @con_id: consumer name
790 *
791 * Returns the PWM device parsed from the phandle and index specified in the
792 * "pwms" property of a device tree node or a negative error-code on failure.
793 * Values parsed from the device tree are stored in the returned PWM device
794 * object.
795 *
796 * If con_id is NULL, the first PWM device listed in the "pwms" property will
797 * be requested. Otherwise the "pwm-names" property is used to do a reverse
798 * lookup of the PWM index. This also means that the "pwm-names" property
799 * becomes mandatory for devices that look up the PWM device via the con_id
800 * parameter.
801 *
802 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
803 * error code on failure.
804 */
805struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
806 const char *con_id)
807{
808 struct pwm_device *pwm = NULL;
809 struct of_phandle_args args;
810 struct device_link *dl;
811 struct pwm_chip *pc;
812 int index = 0;
813 int err;
814
815 if (con_id) {
816 index = of_property_match_string(np, "pwm-names", con_id);
817 if (index < 0)
818 return ERR_PTR(index);
819 }
820
821 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
822 &args);
823 if (err) {
824 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
825 return ERR_PTR(err);
826 }
827
828 pc = of_node_to_pwmchip(args.np);
829 if (IS_ERR(pc)) {
830 if (PTR_ERR(pc) != -EPROBE_DEFER)
831 pr_err("%s(): PWM chip not found\n", __func__);
832
833 pwm = ERR_CAST(pc);
834 goto put;
835 }
836
837 pwm = pc->of_xlate(pc, &args);
838 if (IS_ERR(pwm))
839 goto put;
840
841 dl = pwm_device_link_add(dev, pwm);
842 if (IS_ERR(dl)) {
843 /* of_xlate ended up calling pwm_request_from_chip() */
844 pwm_free(pwm);
845 pwm = ERR_CAST(dl);
846 goto put;
847 }
848
849 /*
850 * If a consumer name was not given, try to look it up from the
851 * "pwm-names" property if it exists. Otherwise use the name of
852 * the user device node.
853 */
854 if (!con_id) {
855 err = of_property_read_string_index(np, "pwm-names", index,
856 &con_id);
857 if (err < 0)
858 con_id = np->name;
859 }
860
861 pwm->label = con_id;
862
863put:
864 of_node_put(args.np);
865
866 return pwm;
867}
868EXPORT_SYMBOL_GPL(of_pwm_get);
869
870#if IS_ENABLED(CONFIG_ACPI)
871static struct pwm_chip *device_to_pwmchip(struct device *dev)
872{
873 struct pwm_chip *chip;
874
875 mutex_lock(&pwm_lock);
876
877 list_for_each_entry(chip, &pwm_chips, list) {
878 struct acpi_device *adev = ACPI_COMPANION(chip->dev);
879
880 if ((chip->dev == dev) || (adev && &adev->dev == dev)) {
881 mutex_unlock(&pwm_lock);
882 return chip;
883 }
884 }
885
886 mutex_unlock(&pwm_lock);
887
888 return ERR_PTR(-EPROBE_DEFER);
889}
890#endif
891
892/**
893 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
894 * @fwnode: firmware node to get the "pwm" property from
895 *
896 * Returns the PWM device parsed from the fwnode and index specified in the
897 * "pwms" property or a negative error-code on failure.
898 * Values parsed from the device tree are stored in the returned PWM device
899 * object.
900 *
901 * This is analogous to of_pwm_get() except con_id is not yet supported.
902 * ACPI entries must look like
903 * Package () {"pwms", Package ()
904 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
905 *
906 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
907 * error code on failure.
908 */
909static struct pwm_device *acpi_pwm_get(struct fwnode_handle *fwnode)
910{
911 struct pwm_device *pwm = ERR_PTR(-ENODEV);
912#if IS_ENABLED(CONFIG_ACPI)
913 struct fwnode_reference_args args;
914 struct acpi_device *acpi;
915 struct pwm_chip *chip;
916 int ret;
917
918 memset(&args, 0, sizeof(args));
919
920 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
921 if (ret < 0)
922 return ERR_PTR(ret);
923
924 acpi = to_acpi_device_node(args.fwnode);
925 if (!acpi)
926 return ERR_PTR(-EINVAL);
927
928 if (args.nargs < 2)
929 return ERR_PTR(-EPROTO);
930
931 chip = device_to_pwmchip(&acpi->dev);
932 if (IS_ERR(chip))
933 return ERR_CAST(chip);
934
935 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
936 if (IS_ERR(pwm))
937 return pwm;
938
939 pwm->args.period = args.args[1];
940 pwm->args.polarity = PWM_POLARITY_NORMAL;
941
942 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
943 pwm->args.polarity = PWM_POLARITY_INVERSED;
944#endif
945
946 return pwm;
947}
948
949/**
950 * pwm_add_table() - register PWM device consumers
951 * @table: array of consumers to register
952 * @num: number of consumers in table
953 */
954void pwm_add_table(struct pwm_lookup *table, size_t num)
955{
956 mutex_lock(&pwm_lookup_lock);
957
958 while (num--) {
959 list_add_tail(&table->list, &pwm_lookup_list);
960 table++;
961 }
962
963 mutex_unlock(&pwm_lookup_lock);
964}
965
966/**
967 * pwm_remove_table() - unregister PWM device consumers
968 * @table: array of consumers to unregister
969 * @num: number of consumers in table
970 */
971void pwm_remove_table(struct pwm_lookup *table, size_t num)
972{
973 mutex_lock(&pwm_lookup_lock);
974
975 while (num--) {
976 list_del(&table->list);
977 table++;
978 }
979
980 mutex_unlock(&pwm_lookup_lock);
981}
982
983/**
984 * pwm_get() - look up and request a PWM device
985 * @dev: device for PWM consumer
986 * @con_id: consumer name
987 *
988 * Lookup is first attempted using DT. If the device was not instantiated from
989 * a device tree, a PWM chip and a relative index is looked up via a table
990 * supplied by board setup code (see pwm_add_table()).
991 *
992 * Once a PWM chip has been found the specified PWM device will be requested
993 * and is ready to be used.
994 *
995 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
996 * error code on failure.
997 */
998struct pwm_device *pwm_get(struct device *dev, const char *con_id)
999{
1000 const char *dev_id = dev ? dev_name(dev) : NULL;
1001 struct pwm_device *pwm;
1002 struct pwm_chip *chip;
1003 struct device_link *dl;
1004 unsigned int best = 0;
1005 struct pwm_lookup *p, *chosen = NULL;
1006 unsigned int match;
1007 int err;
1008
1009 /* look up via DT first */
1010 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
1011 return of_pwm_get(dev, dev->of_node, con_id);
1012
1013 /* then lookup via ACPI */
1014 if (dev && is_acpi_node(dev->fwnode)) {
1015 pwm = acpi_pwm_get(dev->fwnode);
1016 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
1017 return pwm;
1018 }
1019
1020 /*
1021 * We look up the provider in the static table typically provided by
1022 * board setup code. We first try to lookup the consumer device by
1023 * name. If the consumer device was passed in as NULL or if no match
1024 * was found, we try to find the consumer by directly looking it up
1025 * by name.
1026 *
1027 * If a match is found, the provider PWM chip is looked up by name
1028 * and a PWM device is requested using the PWM device per-chip index.
1029 *
1030 * The lookup algorithm was shamelessly taken from the clock
1031 * framework:
1032 *
1033 * We do slightly fuzzy matching here:
1034 * An entry with a NULL ID is assumed to be a wildcard.
1035 * If an entry has a device ID, it must match
1036 * If an entry has a connection ID, it must match
1037 * Then we take the most specific entry - with the following order
1038 * of precedence: dev+con > dev only > con only.
1039 */
1040 mutex_lock(&pwm_lookup_lock);
1041
1042 list_for_each_entry(p, &pwm_lookup_list, list) {
1043 match = 0;
1044
1045 if (p->dev_id) {
1046 if (!dev_id || strcmp(p->dev_id, dev_id))
1047 continue;
1048
1049 match += 2;
1050 }
1051
1052 if (p->con_id) {
1053 if (!con_id || strcmp(p->con_id, con_id))
1054 continue;
1055
1056 match += 1;
1057 }
1058
1059 if (match > best) {
1060 chosen = p;
1061
1062 if (match != 3)
1063 best = match;
1064 else
1065 break;
1066 }
1067 }
1068
1069 mutex_unlock(&pwm_lookup_lock);
1070
1071 if (!chosen)
1072 return ERR_PTR(-ENODEV);
1073
1074 chip = pwmchip_find_by_name(chosen->provider);
1075
1076 /*
1077 * If the lookup entry specifies a module, load the module and retry
1078 * the PWM chip lookup. This can be used to work around driver load
1079 * ordering issues if driver's can't be made to properly support the
1080 * deferred probe mechanism.
1081 */
1082 if (!chip && chosen->module) {
1083 err = request_module(chosen->module);
1084 if (err == 0)
1085 chip = pwmchip_find_by_name(chosen->provider);
1086 }
1087
1088 if (!chip)
1089 return ERR_PTR(-EPROBE_DEFER);
1090
1091 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
1092 if (IS_ERR(pwm))
1093 return pwm;
1094
1095 dl = pwm_device_link_add(dev, pwm);
1096 if (IS_ERR(dl)) {
1097 pwm_free(pwm);
1098 return ERR_CAST(dl);
1099 }
1100
1101 pwm->args.period = chosen->period;
1102 pwm->args.polarity = chosen->polarity;
1103
1104 return pwm;
1105}
1106EXPORT_SYMBOL_GPL(pwm_get);
1107
1108/**
1109 * pwm_put() - release a PWM device
1110 * @pwm: PWM device
1111 */
1112void pwm_put(struct pwm_device *pwm)
1113{
1114 if (!pwm)
1115 return;
1116
1117 mutex_lock(&pwm_lock);
1118
1119 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
1120 pr_warn("PWM device already freed\n");
1121 goto out;
1122 }
1123
1124 if (pwm->chip->ops->free)
1125 pwm->chip->ops->free(pwm->chip, pwm);
1126
1127 pwm_set_chip_data(pwm, NULL);
1128 pwm->label = NULL;
1129
1130 module_put(pwm->chip->ops->owner);
1131out:
1132 mutex_unlock(&pwm_lock);
1133}
1134EXPORT_SYMBOL_GPL(pwm_put);
1135
1136static void devm_pwm_release(struct device *dev, void *res)
1137{
1138 pwm_put(*(struct pwm_device **)res);
1139}
1140
1141/**
1142 * devm_pwm_get() - resource managed pwm_get()
1143 * @dev: device for PWM consumer
1144 * @con_id: consumer name
1145 *
1146 * This function performs like pwm_get() but the acquired PWM device will
1147 * automatically be released on driver detach.
1148 *
1149 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1150 * error code on failure.
1151 */
1152struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
1153{
1154 struct pwm_device **ptr, *pwm;
1155
1156 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1157 if (!ptr)
1158 return ERR_PTR(-ENOMEM);
1159
1160 pwm = pwm_get(dev, con_id);
1161 if (!IS_ERR(pwm)) {
1162 *ptr = pwm;
1163 devres_add(dev, ptr);
1164 } else {
1165 devres_free(ptr);
1166 }
1167
1168 return pwm;
1169}
1170EXPORT_SYMBOL_GPL(devm_pwm_get);
1171
1172/**
1173 * devm_of_pwm_get() - resource managed of_pwm_get()
1174 * @dev: device for PWM consumer
1175 * @np: device node to get the PWM from
1176 * @con_id: consumer name
1177 *
1178 * This function performs like of_pwm_get() but the acquired PWM device will
1179 * automatically be released on driver detach.
1180 *
1181 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1182 * error code on failure.
1183 */
1184struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
1185 const char *con_id)
1186{
1187 struct pwm_device **ptr, *pwm;
1188
1189 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1190 if (!ptr)
1191 return ERR_PTR(-ENOMEM);
1192
1193 pwm = of_pwm_get(dev, np, con_id);
1194 if (!IS_ERR(pwm)) {
1195 *ptr = pwm;
1196 devres_add(dev, ptr);
1197 } else {
1198 devres_free(ptr);
1199 }
1200
1201 return pwm;
1202}
1203EXPORT_SYMBOL_GPL(devm_of_pwm_get);
1204
1205/**
1206 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
1207 * @dev: device for PWM consumer
1208 * @fwnode: firmware node to get the PWM from
1209 * @con_id: consumer name
1210 *
1211 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
1212 * acpi_pwm_get() for a detailed description.
1213 *
1214 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1215 * error code on failure.
1216 */
1217struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
1218 struct fwnode_handle *fwnode,
1219 const char *con_id)
1220{
1221 struct pwm_device **ptr, *pwm = ERR_PTR(-ENODEV);
1222
1223 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1224 if (!ptr)
1225 return ERR_PTR(-ENOMEM);
1226
1227 if (is_of_node(fwnode))
1228 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1229 else if (is_acpi_node(fwnode))
1230 pwm = acpi_pwm_get(fwnode);
1231
1232 if (!IS_ERR(pwm)) {
1233 *ptr = pwm;
1234 devres_add(dev, ptr);
1235 } else {
1236 devres_free(ptr);
1237 }
1238
1239 return pwm;
1240}
1241EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1242
1243static int devm_pwm_match(struct device *dev, void *res, void *data)
1244{
1245 struct pwm_device **p = res;
1246
1247 if (WARN_ON(!p || !*p))
1248 return 0;
1249
1250 return *p == data;
1251}
1252
1253/**
1254 * devm_pwm_put() - resource managed pwm_put()
1255 * @dev: device for PWM consumer
1256 * @pwm: PWM device
1257 *
1258 * Release a PWM previously allocated using devm_pwm_get(). Calling this
1259 * function is usually not needed because devm-allocated resources are
1260 * automatically released on driver detach.
1261 */
1262void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
1263{
1264 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
1265}
1266EXPORT_SYMBOL_GPL(devm_pwm_put);
1267
1268#ifdef CONFIG_DEBUG_FS
1269static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1270{
1271 unsigned int i;
1272
1273 for (i = 0; i < chip->npwm; i++) {
1274 struct pwm_device *pwm = &chip->pwms[i];
1275 struct pwm_state state;
1276
1277 pwm_get_state(pwm, &state);
1278
1279 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1280
1281 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1282 seq_puts(s, " requested");
1283
1284 if (state.enabled)
1285 seq_puts(s, " enabled");
1286
1287 seq_printf(s, " period: %llu ns", state.period);
1288 seq_printf(s, " duty: %llu ns", state.duty_cycle);
1289 seq_printf(s, " polarity: %s",
1290 state.polarity ? "inverse" : "normal");
1291
1292 seq_puts(s, "\n");
1293 }
1294}
1295
1296static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1297{
1298 mutex_lock(&pwm_lock);
1299 s->private = "";
1300
1301 return seq_list_start(&pwm_chips, *pos);
1302}
1303
1304static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1305{
1306 s->private = "\n";
1307
1308 return seq_list_next(v, &pwm_chips, pos);
1309}
1310
1311static void pwm_seq_stop(struct seq_file *s, void *v)
1312{
1313 mutex_unlock(&pwm_lock);
1314}
1315
1316static int pwm_seq_show(struct seq_file *s, void *v)
1317{
1318 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1319
1320 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1321 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1322 dev_name(chip->dev), chip->npwm,
1323 (chip->npwm != 1) ? "s" : "");
1324
1325 pwm_dbg_show(chip, s);
1326
1327 return 0;
1328}
1329
1330static const struct seq_operations pwm_seq_ops = {
1331 .start = pwm_seq_start,
1332 .next = pwm_seq_next,
1333 .stop = pwm_seq_stop,
1334 .show = pwm_seq_show,
1335};
1336
1337static int pwm_seq_open(struct inode *inode, struct file *file)
1338{
1339 return seq_open(file, &pwm_seq_ops);
1340}
1341
1342static const struct file_operations pwm_debugfs_ops = {
1343 .owner = THIS_MODULE,
1344 .open = pwm_seq_open,
1345 .read = seq_read,
1346 .llseek = seq_lseek,
1347 .release = seq_release,
1348};
1349
1350static int __init pwm_debugfs_init(void)
1351{
1352 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
1353 &pwm_debugfs_ops);
1354
1355 return 0;
1356}
1357subsys_initcall(pwm_debugfs_init);
1358#endif /* CONFIG_DEBUG_FS */
1/*
2 * Generic pwmlib implementation
3 *
4 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
5 * Copyright (C) 2011-2012 Avionic Design GmbH
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2, or (at your option)
10 * any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; see the file COPYING. If not, write to
19 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include <linux/module.h>
23#include <linux/pwm.h>
24#include <linux/radix-tree.h>
25#include <linux/list.h>
26#include <linux/mutex.h>
27#include <linux/err.h>
28#include <linux/slab.h>
29#include <linux/device.h>
30#include <linux/debugfs.h>
31#include <linux/seq_file.h>
32
33#include <dt-bindings/pwm/pwm.h>
34
35#define MAX_PWMS 1024
36
37static DEFINE_MUTEX(pwm_lookup_lock);
38static LIST_HEAD(pwm_lookup_list);
39static DEFINE_MUTEX(pwm_lock);
40static LIST_HEAD(pwm_chips);
41static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
42static RADIX_TREE(pwm_tree, GFP_KERNEL);
43
44static struct pwm_device *pwm_to_device(unsigned int pwm)
45{
46 return radix_tree_lookup(&pwm_tree, pwm);
47}
48
49static int alloc_pwms(int pwm, unsigned int count)
50{
51 unsigned int from = 0;
52 unsigned int start;
53
54 if (pwm >= MAX_PWMS)
55 return -EINVAL;
56
57 if (pwm >= 0)
58 from = pwm;
59
60 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
61 count, 0);
62
63 if (pwm >= 0 && start != pwm)
64 return -EEXIST;
65
66 if (start + count > MAX_PWMS)
67 return -ENOSPC;
68
69 return start;
70}
71
72static void free_pwms(struct pwm_chip *chip)
73{
74 unsigned int i;
75
76 for (i = 0; i < chip->npwm; i++) {
77 struct pwm_device *pwm = &chip->pwms[i];
78 radix_tree_delete(&pwm_tree, pwm->pwm);
79 }
80
81 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
82
83 kfree(chip->pwms);
84 chip->pwms = NULL;
85}
86
87static struct pwm_chip *pwmchip_find_by_name(const char *name)
88{
89 struct pwm_chip *chip;
90
91 if (!name)
92 return NULL;
93
94 mutex_lock(&pwm_lock);
95
96 list_for_each_entry(chip, &pwm_chips, list) {
97 const char *chip_name = dev_name(chip->dev);
98
99 if (chip_name && strcmp(chip_name, name) == 0) {
100 mutex_unlock(&pwm_lock);
101 return chip;
102 }
103 }
104
105 mutex_unlock(&pwm_lock);
106
107 return NULL;
108}
109
110static int pwm_device_request(struct pwm_device *pwm, const char *label)
111{
112 int err;
113
114 if (test_bit(PWMF_REQUESTED, &pwm->flags))
115 return -EBUSY;
116
117 if (!try_module_get(pwm->chip->ops->owner))
118 return -ENODEV;
119
120 if (pwm->chip->ops->request) {
121 err = pwm->chip->ops->request(pwm->chip, pwm);
122 if (err) {
123 module_put(pwm->chip->ops->owner);
124 return err;
125 }
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 if (pc->of_pwm_n_cells < 3)
140 return ERR_PTR(-EINVAL);
141
142 if (args->args[0] >= pc->npwm)
143 return ERR_PTR(-EINVAL);
144
145 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
146 if (IS_ERR(pwm))
147 return pwm;
148
149 pwm_set_period(pwm, args->args[1]);
150
151 if (args->args[2] & PWM_POLARITY_INVERTED)
152 pwm_set_polarity(pwm, PWM_POLARITY_INVERSED);
153 else
154 pwm_set_polarity(pwm, PWM_POLARITY_NORMAL);
155
156 return pwm;
157}
158EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
159
160static struct pwm_device *
161of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
162{
163 struct pwm_device *pwm;
164
165 if (pc->of_pwm_n_cells < 2)
166 return ERR_PTR(-EINVAL);
167
168 if (args->args[0] >= pc->npwm)
169 return ERR_PTR(-EINVAL);
170
171 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
172 if (IS_ERR(pwm))
173 return pwm;
174
175 pwm_set_period(pwm, args->args[1]);
176
177 return pwm;
178}
179
180static void of_pwmchip_add(struct pwm_chip *chip)
181{
182 if (!chip->dev || !chip->dev->of_node)
183 return;
184
185 if (!chip->of_xlate) {
186 chip->of_xlate = of_pwm_simple_xlate;
187 chip->of_pwm_n_cells = 2;
188 }
189
190 of_node_get(chip->dev->of_node);
191}
192
193static void of_pwmchip_remove(struct pwm_chip *chip)
194{
195 if (chip->dev && chip->dev->of_node)
196 of_node_put(chip->dev->of_node);
197}
198
199/**
200 * pwm_set_chip_data() - set private chip data for a PWM
201 * @pwm: PWM device
202 * @data: pointer to chip-specific data
203 */
204int pwm_set_chip_data(struct pwm_device *pwm, void *data)
205{
206 if (!pwm)
207 return -EINVAL;
208
209 pwm->chip_data = data;
210
211 return 0;
212}
213EXPORT_SYMBOL_GPL(pwm_set_chip_data);
214
215/**
216 * pwm_get_chip_data() - get private chip data for a PWM
217 * @pwm: PWM device
218 */
219void *pwm_get_chip_data(struct pwm_device *pwm)
220{
221 return pwm ? pwm->chip_data : NULL;
222}
223EXPORT_SYMBOL_GPL(pwm_get_chip_data);
224
225/**
226 * pwmchip_add() - register a new PWM chip
227 * @chip: the PWM chip to add
228 *
229 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
230 * will be used.
231 */
232int pwmchip_add(struct pwm_chip *chip)
233{
234 struct pwm_device *pwm;
235 unsigned int i;
236 int ret;
237
238 if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
239 !chip->ops->enable || !chip->ops->disable)
240 return -EINVAL;
241
242 mutex_lock(&pwm_lock);
243
244 ret = alloc_pwms(chip->base, chip->npwm);
245 if (ret < 0)
246 goto out;
247
248 chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL);
249 if (!chip->pwms) {
250 ret = -ENOMEM;
251 goto out;
252 }
253
254 chip->base = ret;
255
256 for (i = 0; i < chip->npwm; i++) {
257 pwm = &chip->pwms[i];
258
259 pwm->chip = chip;
260 pwm->pwm = chip->base + i;
261 pwm->hwpwm = i;
262
263 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
264 }
265
266 bitmap_set(allocated_pwms, chip->base, chip->npwm);
267
268 INIT_LIST_HEAD(&chip->list);
269 list_add(&chip->list, &pwm_chips);
270
271 ret = 0;
272
273 if (IS_ENABLED(CONFIG_OF))
274 of_pwmchip_add(chip);
275
276 pwmchip_sysfs_export(chip);
277
278out:
279 mutex_unlock(&pwm_lock);
280 return ret;
281}
282EXPORT_SYMBOL_GPL(pwmchip_add);
283
284/**
285 * pwmchip_remove() - remove a PWM chip
286 * @chip: the PWM chip to remove
287 *
288 * Removes a PWM chip. This function may return busy if the PWM chip provides
289 * a PWM device that is still requested.
290 */
291int pwmchip_remove(struct pwm_chip *chip)
292{
293 unsigned int i;
294 int ret = 0;
295
296 mutex_lock(&pwm_lock);
297
298 for (i = 0; i < chip->npwm; i++) {
299 struct pwm_device *pwm = &chip->pwms[i];
300
301 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
302 ret = -EBUSY;
303 goto out;
304 }
305 }
306
307 list_del_init(&chip->list);
308
309 if (IS_ENABLED(CONFIG_OF))
310 of_pwmchip_remove(chip);
311
312 free_pwms(chip);
313
314 pwmchip_sysfs_unexport(chip);
315
316out:
317 mutex_unlock(&pwm_lock);
318 return ret;
319}
320EXPORT_SYMBOL_GPL(pwmchip_remove);
321
322/**
323 * pwm_request() - request a PWM device
324 * @pwm_id: global PWM device index
325 * @label: PWM device label
326 *
327 * This function is deprecated, use pwm_get() instead.
328 */
329struct pwm_device *pwm_request(int pwm, const char *label)
330{
331 struct pwm_device *dev;
332 int err;
333
334 if (pwm < 0 || pwm >= MAX_PWMS)
335 return ERR_PTR(-EINVAL);
336
337 mutex_lock(&pwm_lock);
338
339 dev = pwm_to_device(pwm);
340 if (!dev) {
341 dev = ERR_PTR(-EPROBE_DEFER);
342 goto out;
343 }
344
345 err = pwm_device_request(dev, label);
346 if (err < 0)
347 dev = ERR_PTR(err);
348
349out:
350 mutex_unlock(&pwm_lock);
351
352 return dev;
353}
354EXPORT_SYMBOL_GPL(pwm_request);
355
356/**
357 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
358 * @chip: PWM chip
359 * @index: per-chip index of the PWM to request
360 * @label: a literal description string of this PWM
361 *
362 * Returns the PWM at the given index of the given PWM chip. A negative error
363 * code is returned if the index is not valid for the specified PWM chip or
364 * if the PWM device cannot be requested.
365 */
366struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
367 unsigned int index,
368 const char *label)
369{
370 struct pwm_device *pwm;
371 int err;
372
373 if (!chip || index >= chip->npwm)
374 return ERR_PTR(-EINVAL);
375
376 mutex_lock(&pwm_lock);
377 pwm = &chip->pwms[index];
378
379 err = pwm_device_request(pwm, label);
380 if (err < 0)
381 pwm = ERR_PTR(err);
382
383 mutex_unlock(&pwm_lock);
384 return pwm;
385}
386EXPORT_SYMBOL_GPL(pwm_request_from_chip);
387
388/**
389 * pwm_free() - free a PWM device
390 * @pwm: PWM device
391 *
392 * This function is deprecated, use pwm_put() instead.
393 */
394void pwm_free(struct pwm_device *pwm)
395{
396 pwm_put(pwm);
397}
398EXPORT_SYMBOL_GPL(pwm_free);
399
400/**
401 * pwm_config() - change a PWM device configuration
402 * @pwm: PWM device
403 * @duty_ns: "on" time (in nanoseconds)
404 * @period_ns: duration (in nanoseconds) of one cycle
405 */
406int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
407{
408 int err;
409
410 if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
411 return -EINVAL;
412
413 err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
414 if (err)
415 return err;
416
417 pwm->duty_cycle = duty_ns;
418 pwm->period = period_ns;
419
420 return 0;
421}
422EXPORT_SYMBOL_GPL(pwm_config);
423
424/**
425 * pwm_set_polarity() - configure the polarity of a PWM signal
426 * @pwm: PWM device
427 * @polarity: new polarity of the PWM signal
428 *
429 * Note that the polarity cannot be configured while the PWM device is enabled
430 */
431int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
432{
433 int err;
434
435 if (!pwm || !pwm->chip->ops)
436 return -EINVAL;
437
438 if (!pwm->chip->ops->set_polarity)
439 return -ENOSYS;
440
441 if (test_bit(PWMF_ENABLED, &pwm->flags))
442 return -EBUSY;
443
444 err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
445 if (err)
446 return err;
447
448 pwm->polarity = polarity;
449
450 return 0;
451}
452EXPORT_SYMBOL_GPL(pwm_set_polarity);
453
454/**
455 * pwm_enable() - start a PWM output toggling
456 * @pwm: PWM device
457 */
458int pwm_enable(struct pwm_device *pwm)
459{
460 if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags))
461 return pwm->chip->ops->enable(pwm->chip, pwm);
462
463 return pwm ? 0 : -EINVAL;
464}
465EXPORT_SYMBOL_GPL(pwm_enable);
466
467/**
468 * pwm_disable() - stop a PWM output toggling
469 * @pwm: PWM device
470 */
471void pwm_disable(struct pwm_device *pwm)
472{
473 if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
474 pwm->chip->ops->disable(pwm->chip, pwm);
475}
476EXPORT_SYMBOL_GPL(pwm_disable);
477
478static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
479{
480 struct pwm_chip *chip;
481
482 mutex_lock(&pwm_lock);
483
484 list_for_each_entry(chip, &pwm_chips, list)
485 if (chip->dev && chip->dev->of_node == np) {
486 mutex_unlock(&pwm_lock);
487 return chip;
488 }
489
490 mutex_unlock(&pwm_lock);
491
492 return ERR_PTR(-EPROBE_DEFER);
493}
494
495/**
496 * of_pwm_get() - request a PWM via the PWM framework
497 * @np: device node to get the PWM from
498 * @con_id: consumer name
499 *
500 * Returns the PWM device parsed from the phandle and index specified in the
501 * "pwms" property of a device tree node or a negative error-code on failure.
502 * Values parsed from the device tree are stored in the returned PWM device
503 * object.
504 *
505 * If con_id is NULL, the first PWM device listed in the "pwms" property will
506 * be requested. Otherwise the "pwm-names" property is used to do a reverse
507 * lookup of the PWM index. This also means that the "pwm-names" property
508 * becomes mandatory for devices that look up the PWM device via the con_id
509 * parameter.
510 */
511struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
512{
513 struct pwm_device *pwm = NULL;
514 struct of_phandle_args args;
515 struct pwm_chip *pc;
516 int index = 0;
517 int err;
518
519 if (con_id) {
520 index = of_property_match_string(np, "pwm-names", con_id);
521 if (index < 0)
522 return ERR_PTR(index);
523 }
524
525 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
526 &args);
527 if (err) {
528 pr_debug("%s(): can't parse \"pwms\" property\n", __func__);
529 return ERR_PTR(err);
530 }
531
532 pc = of_node_to_pwmchip(args.np);
533 if (IS_ERR(pc)) {
534 pr_debug("%s(): PWM chip not found\n", __func__);
535 pwm = ERR_CAST(pc);
536 goto put;
537 }
538
539 if (args.args_count != pc->of_pwm_n_cells) {
540 pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name,
541 args.np->full_name);
542 pwm = ERR_PTR(-EINVAL);
543 goto put;
544 }
545
546 pwm = pc->of_xlate(pc, &args);
547 if (IS_ERR(pwm))
548 goto put;
549
550 /*
551 * If a consumer name was not given, try to look it up from the
552 * "pwm-names" property if it exists. Otherwise use the name of
553 * the user device node.
554 */
555 if (!con_id) {
556 err = of_property_read_string_index(np, "pwm-names", index,
557 &con_id);
558 if (err < 0)
559 con_id = np->name;
560 }
561
562 pwm->label = con_id;
563
564put:
565 of_node_put(args.np);
566
567 return pwm;
568}
569EXPORT_SYMBOL_GPL(of_pwm_get);
570
571/**
572 * pwm_add_table() - register PWM device consumers
573 * @table: array of consumers to register
574 * @num: number of consumers in table
575 */
576void __init pwm_add_table(struct pwm_lookup *table, size_t num)
577{
578 mutex_lock(&pwm_lookup_lock);
579
580 while (num--) {
581 list_add_tail(&table->list, &pwm_lookup_list);
582 table++;
583 }
584
585 mutex_unlock(&pwm_lookup_lock);
586}
587
588/**
589 * pwm_get() - look up and request a PWM device
590 * @dev: device for PWM consumer
591 * @con_id: consumer name
592 *
593 * Lookup is first attempted using DT. If the device was not instantiated from
594 * a device tree, a PWM chip and a relative index is looked up via a table
595 * supplied by board setup code (see pwm_add_table()).
596 *
597 * Once a PWM chip has been found the specified PWM device will be requested
598 * and is ready to be used.
599 */
600struct pwm_device *pwm_get(struct device *dev, const char *con_id)
601{
602 struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER);
603 const char *dev_id = dev ? dev_name(dev) : NULL;
604 struct pwm_chip *chip = NULL;
605 unsigned int index = 0;
606 unsigned int best = 0;
607 struct pwm_lookup *p;
608 unsigned int match;
609
610 /* look up via DT first */
611 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
612 return of_pwm_get(dev->of_node, con_id);
613
614 /*
615 * We look up the provider in the static table typically provided by
616 * board setup code. We first try to lookup the consumer device by
617 * name. If the consumer device was passed in as NULL or if no match
618 * was found, we try to find the consumer by directly looking it up
619 * by name.
620 *
621 * If a match is found, the provider PWM chip is looked up by name
622 * and a PWM device is requested using the PWM device per-chip index.
623 *
624 * The lookup algorithm was shamelessly taken from the clock
625 * framework:
626 *
627 * We do slightly fuzzy matching here:
628 * An entry with a NULL ID is assumed to be a wildcard.
629 * If an entry has a device ID, it must match
630 * If an entry has a connection ID, it must match
631 * Then we take the most specific entry - with the following order
632 * of precedence: dev+con > dev only > con only.
633 */
634 mutex_lock(&pwm_lookup_lock);
635
636 list_for_each_entry(p, &pwm_lookup_list, list) {
637 match = 0;
638
639 if (p->dev_id) {
640 if (!dev_id || strcmp(p->dev_id, dev_id))
641 continue;
642
643 match += 2;
644 }
645
646 if (p->con_id) {
647 if (!con_id || strcmp(p->con_id, con_id))
648 continue;
649
650 match += 1;
651 }
652
653 if (match > best) {
654 chip = pwmchip_find_by_name(p->provider);
655 index = p->index;
656
657 if (match != 3)
658 best = match;
659 else
660 break;
661 }
662 }
663
664 if (chip)
665 pwm = pwm_request_from_chip(chip, index, con_id ?: dev_id);
666
667 mutex_unlock(&pwm_lookup_lock);
668
669 return pwm;
670}
671EXPORT_SYMBOL_GPL(pwm_get);
672
673/**
674 * pwm_put() - release a PWM device
675 * @pwm: PWM device
676 */
677void pwm_put(struct pwm_device *pwm)
678{
679 if (!pwm)
680 return;
681
682 mutex_lock(&pwm_lock);
683
684 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
685 pr_warn("PWM device already freed\n");
686 goto out;
687 }
688
689 if (pwm->chip->ops->free)
690 pwm->chip->ops->free(pwm->chip, pwm);
691
692 pwm->label = NULL;
693
694 module_put(pwm->chip->ops->owner);
695out:
696 mutex_unlock(&pwm_lock);
697}
698EXPORT_SYMBOL_GPL(pwm_put);
699
700static void devm_pwm_release(struct device *dev, void *res)
701{
702 pwm_put(*(struct pwm_device **)res);
703}
704
705/**
706 * devm_pwm_get() - resource managed pwm_get()
707 * @dev: device for PWM consumer
708 * @con_id: consumer name
709 *
710 * This function performs like pwm_get() but the acquired PWM device will
711 * automatically be released on driver detach.
712 */
713struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
714{
715 struct pwm_device **ptr, *pwm;
716
717 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
718 if (!ptr)
719 return ERR_PTR(-ENOMEM);
720
721 pwm = pwm_get(dev, con_id);
722 if (!IS_ERR(pwm)) {
723 *ptr = pwm;
724 devres_add(dev, ptr);
725 } else {
726 devres_free(ptr);
727 }
728
729 return pwm;
730}
731EXPORT_SYMBOL_GPL(devm_pwm_get);
732
733/**
734 * devm_of_pwm_get() - resource managed of_pwm_get()
735 * @dev: device for PWM consumer
736 * @np: device node to get the PWM from
737 * @con_id: consumer name
738 *
739 * This function performs like of_pwm_get() but the acquired PWM device will
740 * automatically be released on driver detach.
741 */
742struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
743 const char *con_id)
744{
745 struct pwm_device **ptr, *pwm;
746
747 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
748 if (!ptr)
749 return ERR_PTR(-ENOMEM);
750
751 pwm = of_pwm_get(np, con_id);
752 if (!IS_ERR(pwm)) {
753 *ptr = pwm;
754 devres_add(dev, ptr);
755 } else {
756 devres_free(ptr);
757 }
758
759 return pwm;
760}
761EXPORT_SYMBOL_GPL(devm_of_pwm_get);
762
763static int devm_pwm_match(struct device *dev, void *res, void *data)
764{
765 struct pwm_device **p = res;
766
767 if (WARN_ON(!p || !*p))
768 return 0;
769
770 return *p == data;
771}
772
773/**
774 * devm_pwm_put() - resource managed pwm_put()
775 * @dev: device for PWM consumer
776 * @pwm: PWM device
777 *
778 * Release a PWM previously allocated using devm_pwm_get(). Calling this
779 * function is usually not needed because devm-allocated resources are
780 * automatically released on driver detach.
781 */
782void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
783{
784 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
785}
786EXPORT_SYMBOL_GPL(devm_pwm_put);
787
788/**
789 * pwm_can_sleep() - report whether PWM access will sleep
790 * @pwm: PWM device
791 *
792 * It returns true if accessing the PWM can sleep, false otherwise.
793 */
794bool pwm_can_sleep(struct pwm_device *pwm)
795{
796 return pwm->chip->can_sleep;
797}
798EXPORT_SYMBOL_GPL(pwm_can_sleep);
799
800#ifdef CONFIG_DEBUG_FS
801static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
802{
803 unsigned int i;
804
805 for (i = 0; i < chip->npwm; i++) {
806 struct pwm_device *pwm = &chip->pwms[i];
807
808 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
809
810 if (test_bit(PWMF_REQUESTED, &pwm->flags))
811 seq_puts(s, " requested");
812
813 if (test_bit(PWMF_ENABLED, &pwm->flags))
814 seq_puts(s, " enabled");
815
816 seq_puts(s, "\n");
817 }
818}
819
820static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
821{
822 mutex_lock(&pwm_lock);
823 s->private = "";
824
825 return seq_list_start(&pwm_chips, *pos);
826}
827
828static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
829{
830 s->private = "\n";
831
832 return seq_list_next(v, &pwm_chips, pos);
833}
834
835static void pwm_seq_stop(struct seq_file *s, void *v)
836{
837 mutex_unlock(&pwm_lock);
838}
839
840static int pwm_seq_show(struct seq_file *s, void *v)
841{
842 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
843
844 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
845 chip->dev->bus ? chip->dev->bus->name : "no-bus",
846 dev_name(chip->dev), chip->npwm,
847 (chip->npwm != 1) ? "s" : "");
848
849 if (chip->ops->dbg_show)
850 chip->ops->dbg_show(chip, s);
851 else
852 pwm_dbg_show(chip, s);
853
854 return 0;
855}
856
857static const struct seq_operations pwm_seq_ops = {
858 .start = pwm_seq_start,
859 .next = pwm_seq_next,
860 .stop = pwm_seq_stop,
861 .show = pwm_seq_show,
862};
863
864static int pwm_seq_open(struct inode *inode, struct file *file)
865{
866 return seq_open(file, &pwm_seq_ops);
867}
868
869static const struct file_operations pwm_debugfs_ops = {
870 .owner = THIS_MODULE,
871 .open = pwm_seq_open,
872 .read = seq_read,
873 .llseek = seq_lseek,
874 .release = seq_release,
875};
876
877static int __init pwm_debugfs_init(void)
878{
879 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
880 &pwm_debugfs_ops);
881
882 return 0;
883}
884
885subsys_initcall(pwm_debugfs_init);
886#endif /* CONFIG_DEBUG_FS */