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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 */