Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux/fpc-iii.git] / drivers / pwm / core.c
bloba80471399c20314edb69442bac0fe57cf06efec9
1 /*
2 * Generic pwmlib implementation
4 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
5 * Copyright (C) 2011-2012 Avionic Design GmbH
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.
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.
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.
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>
33 #include <dt-bindings/pwm/pwm.h>
35 #define MAX_PWMS 1024
37 static DEFINE_MUTEX(pwm_lookup_lock);
38 static LIST_HEAD(pwm_lookup_list);
39 static DEFINE_MUTEX(pwm_lock);
40 static LIST_HEAD(pwm_chips);
41 static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
42 static RADIX_TREE(pwm_tree, GFP_KERNEL);
44 static struct pwm_device *pwm_to_device(unsigned int pwm)
46 return radix_tree_lookup(&pwm_tree, pwm);
49 static int alloc_pwms(int pwm, unsigned int count)
51 unsigned int from = 0;
52 unsigned int start;
54 if (pwm >= MAX_PWMS)
55 return -EINVAL;
57 if (pwm >= 0)
58 from = pwm;
60 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
61 count, 0);
63 if (pwm >= 0 && start != pwm)
64 return -EEXIST;
66 if (start + count > MAX_PWMS)
67 return -ENOSPC;
69 return start;
72 static void free_pwms(struct pwm_chip *chip)
74 unsigned int i;
76 for (i = 0; i < chip->npwm; i++) {
77 struct pwm_device *pwm = &chip->pwms[i];
78 radix_tree_delete(&pwm_tree, pwm->pwm);
81 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
83 kfree(chip->pwms);
84 chip->pwms = NULL;
87 static struct pwm_chip *pwmchip_find_by_name(const char *name)
89 struct pwm_chip *chip;
91 if (!name)
92 return NULL;
94 mutex_lock(&pwm_lock);
96 list_for_each_entry(chip, &pwm_chips, list) {
97 const char *chip_name = dev_name(chip->dev);
99 if (chip_name && strcmp(chip_name, name) == 0) {
100 mutex_unlock(&pwm_lock);
101 return chip;
105 mutex_unlock(&pwm_lock);
107 return NULL;
110 static int pwm_device_request(struct pwm_device *pwm, const char *label)
112 int err;
114 if (test_bit(PWMF_REQUESTED, &pwm->flags))
115 return -EBUSY;
117 if (!try_module_get(pwm->chip->ops->owner))
118 return -ENODEV;
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;
128 set_bit(PWMF_REQUESTED, &pwm->flags);
129 pwm->label = label;
131 return 0;
134 struct pwm_device *
135 of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
137 struct pwm_device *pwm;
139 if (pc->of_pwm_n_cells < 3)
140 return ERR_PTR(-EINVAL);
142 if (args->args[0] >= pc->npwm)
143 return ERR_PTR(-EINVAL);
145 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
146 if (IS_ERR(pwm))
147 return pwm;
149 pwm_set_period(pwm, args->args[1]);
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);
156 return pwm;
158 EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
160 static struct pwm_device *
161 of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
163 struct pwm_device *pwm;
165 if (pc->of_pwm_n_cells < 2)
166 return ERR_PTR(-EINVAL);
168 if (args->args[0] >= pc->npwm)
169 return ERR_PTR(-EINVAL);
171 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
172 if (IS_ERR(pwm))
173 return pwm;
175 pwm_set_period(pwm, args->args[1]);
177 return pwm;
180 static void of_pwmchip_add(struct pwm_chip *chip)
182 if (!chip->dev || !chip->dev->of_node)
183 return;
185 if (!chip->of_xlate) {
186 chip->of_xlate = of_pwm_simple_xlate;
187 chip->of_pwm_n_cells = 2;
190 of_node_get(chip->dev->of_node);
193 static void of_pwmchip_remove(struct pwm_chip *chip)
195 if (chip->dev && chip->dev->of_node)
196 of_node_put(chip->dev->of_node);
200 * pwm_set_chip_data() - set private chip data for a PWM
201 * @pwm: PWM device
202 * @data: pointer to chip-specific data
204 int pwm_set_chip_data(struct pwm_device *pwm, void *data)
206 if (!pwm)
207 return -EINVAL;
209 pwm->chip_data = data;
211 return 0;
213 EXPORT_SYMBOL_GPL(pwm_set_chip_data);
216 * pwm_get_chip_data() - get private chip data for a PWM
217 * @pwm: PWM device
219 void *pwm_get_chip_data(struct pwm_device *pwm)
221 return pwm ? pwm->chip_data : NULL;
223 EXPORT_SYMBOL_GPL(pwm_get_chip_data);
226 * pwmchip_add() - register a new PWM chip
227 * @chip: the PWM chip to add
229 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
230 * will be used.
232 int pwmchip_add(struct pwm_chip *chip)
234 struct pwm_device *pwm;
235 unsigned int i;
236 int ret;
238 if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
239 !chip->ops->enable || !chip->ops->disable)
240 return -EINVAL;
242 mutex_lock(&pwm_lock);
244 ret = alloc_pwms(chip->base, chip->npwm);
245 if (ret < 0)
246 goto out;
248 chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL);
249 if (!chip->pwms) {
250 ret = -ENOMEM;
251 goto out;
254 chip->base = ret;
256 for (i = 0; i < chip->npwm; i++) {
257 pwm = &chip->pwms[i];
259 pwm->chip = chip;
260 pwm->pwm = chip->base + i;
261 pwm->hwpwm = i;
263 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
266 bitmap_set(allocated_pwms, chip->base, chip->npwm);
268 INIT_LIST_HEAD(&chip->list);
269 list_add(&chip->list, &pwm_chips);
271 ret = 0;
273 if (IS_ENABLED(CONFIG_OF))
274 of_pwmchip_add(chip);
276 pwmchip_sysfs_export(chip);
278 out:
279 mutex_unlock(&pwm_lock);
280 return ret;
282 EXPORT_SYMBOL_GPL(pwmchip_add);
285 * pwmchip_remove() - remove a PWM chip
286 * @chip: the PWM chip to remove
288 * Removes a PWM chip. This function may return busy if the PWM chip provides
289 * a PWM device that is still requested.
291 int pwmchip_remove(struct pwm_chip *chip)
293 unsigned int i;
294 int ret = 0;
296 mutex_lock(&pwm_lock);
298 for (i = 0; i < chip->npwm; i++) {
299 struct pwm_device *pwm = &chip->pwms[i];
301 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
302 ret = -EBUSY;
303 goto out;
307 list_del_init(&chip->list);
309 if (IS_ENABLED(CONFIG_OF))
310 of_pwmchip_remove(chip);
312 free_pwms(chip);
314 pwmchip_sysfs_unexport(chip);
316 out:
317 mutex_unlock(&pwm_lock);
318 return ret;
320 EXPORT_SYMBOL_GPL(pwmchip_remove);
323 * pwm_request() - request a PWM device
324 * @pwm_id: global PWM device index
325 * @label: PWM device label
327 * This function is deprecated, use pwm_get() instead.
329 struct pwm_device *pwm_request(int pwm, const char *label)
331 struct pwm_device *dev;
332 int err;
334 if (pwm < 0 || pwm >= MAX_PWMS)
335 return ERR_PTR(-EINVAL);
337 mutex_lock(&pwm_lock);
339 dev = pwm_to_device(pwm);
340 if (!dev) {
341 dev = ERR_PTR(-EPROBE_DEFER);
342 goto out;
345 err = pwm_device_request(dev, label);
346 if (err < 0)
347 dev = ERR_PTR(err);
349 out:
350 mutex_unlock(&pwm_lock);
352 return dev;
354 EXPORT_SYMBOL_GPL(pwm_request);
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
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.
366 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
367 unsigned int index,
368 const char *label)
370 struct pwm_device *pwm;
371 int err;
373 if (!chip || index >= chip->npwm)
374 return ERR_PTR(-EINVAL);
376 mutex_lock(&pwm_lock);
377 pwm = &chip->pwms[index];
379 err = pwm_device_request(pwm, label);
380 if (err < 0)
381 pwm = ERR_PTR(err);
383 mutex_unlock(&pwm_lock);
384 return pwm;
386 EXPORT_SYMBOL_GPL(pwm_request_from_chip);
389 * pwm_free() - free a PWM device
390 * @pwm: PWM device
392 * This function is deprecated, use pwm_put() instead.
394 void pwm_free(struct pwm_device *pwm)
396 pwm_put(pwm);
398 EXPORT_SYMBOL_GPL(pwm_free);
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
406 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
408 int err;
410 if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
411 return -EINVAL;
413 err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
414 if (err)
415 return err;
417 pwm->duty_cycle = duty_ns;
418 pwm->period = period_ns;
420 return 0;
422 EXPORT_SYMBOL_GPL(pwm_config);
425 * pwm_set_polarity() - configure the polarity of a PWM signal
426 * @pwm: PWM device
427 * @polarity: new polarity of the PWM signal
429 * Note that the polarity cannot be configured while the PWM device is enabled
431 int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
433 int err;
435 if (!pwm || !pwm->chip->ops)
436 return -EINVAL;
438 if (!pwm->chip->ops->set_polarity)
439 return -ENOSYS;
441 if (test_bit(PWMF_ENABLED, &pwm->flags))
442 return -EBUSY;
444 err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
445 if (err)
446 return err;
448 pwm->polarity = polarity;
450 return 0;
452 EXPORT_SYMBOL_GPL(pwm_set_polarity);
455 * pwm_enable() - start a PWM output toggling
456 * @pwm: PWM device
458 int pwm_enable(struct pwm_device *pwm)
460 if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags))
461 return pwm->chip->ops->enable(pwm->chip, pwm);
463 return pwm ? 0 : -EINVAL;
465 EXPORT_SYMBOL_GPL(pwm_enable);
468 * pwm_disable() - stop a PWM output toggling
469 * @pwm: PWM device
471 void pwm_disable(struct pwm_device *pwm)
473 if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
474 pwm->chip->ops->disable(pwm->chip, pwm);
476 EXPORT_SYMBOL_GPL(pwm_disable);
478 static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
480 struct pwm_chip *chip;
482 mutex_lock(&pwm_lock);
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;
490 mutex_unlock(&pwm_lock);
492 return ERR_PTR(-EPROBE_DEFER);
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
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.
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.
511 struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
513 struct pwm_device *pwm = NULL;
514 struct of_phandle_args args;
515 struct pwm_chip *pc;
516 int index = 0;
517 int err;
519 if (con_id) {
520 index = of_property_match_string(np, "pwm-names", con_id);
521 if (index < 0)
522 return ERR_PTR(index);
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);
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;
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;
546 pwm = pc->of_xlate(pc, &args);
547 if (IS_ERR(pwm))
548 goto put;
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.
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;
562 pwm->label = con_id;
564 put:
565 of_node_put(args.np);
567 return pwm;
569 EXPORT_SYMBOL_GPL(of_pwm_get);
572 * pwm_add_table() - register PWM device consumers
573 * @table: array of consumers to register
574 * @num: number of consumers in table
576 void __init pwm_add_table(struct pwm_lookup *table, size_t num)
578 mutex_lock(&pwm_lookup_lock);
580 while (num--) {
581 list_add_tail(&table->list, &pwm_lookup_list);
582 table++;
585 mutex_unlock(&pwm_lookup_lock);
589 * pwm_get() - look up and request a PWM device
590 * @dev: device for PWM consumer
591 * @con_id: consumer name
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()).
597 * Once a PWM chip has been found the specified PWM device will be requested
598 * and is ready to be used.
600 struct pwm_device *pwm_get(struct device *dev, const char *con_id)
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;
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);
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.
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.
624 * The lookup algorithm was shamelessly taken from the clock
625 * framework:
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.
634 mutex_lock(&pwm_lookup_lock);
636 list_for_each_entry(p, &pwm_lookup_list, list) {
637 match = 0;
639 if (p->dev_id) {
640 if (!dev_id || strcmp(p->dev_id, dev_id))
641 continue;
643 match += 2;
646 if (p->con_id) {
647 if (!con_id || strcmp(p->con_id, con_id))
648 continue;
650 match += 1;
653 if (match > best) {
654 chip = pwmchip_find_by_name(p->provider);
655 index = p->index;
657 if (match != 3)
658 best = match;
659 else
660 break;
664 if (chip)
665 pwm = pwm_request_from_chip(chip, index, con_id ?: dev_id);
667 mutex_unlock(&pwm_lookup_lock);
669 return pwm;
671 EXPORT_SYMBOL_GPL(pwm_get);
674 * pwm_put() - release a PWM device
675 * @pwm: PWM device
677 void pwm_put(struct pwm_device *pwm)
679 if (!pwm)
680 return;
682 mutex_lock(&pwm_lock);
684 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
685 pr_warn("PWM device already freed\n");
686 goto out;
689 if (pwm->chip->ops->free)
690 pwm->chip->ops->free(pwm->chip, pwm);
692 pwm->label = NULL;
694 module_put(pwm->chip->ops->owner);
695 out:
696 mutex_unlock(&pwm_lock);
698 EXPORT_SYMBOL_GPL(pwm_put);
700 static void devm_pwm_release(struct device *dev, void *res)
702 pwm_put(*(struct pwm_device **)res);
706 * devm_pwm_get() - resource managed pwm_get()
707 * @dev: device for PWM consumer
708 * @con_id: consumer name
710 * This function performs like pwm_get() but the acquired PWM device will
711 * automatically be released on driver detach.
713 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
715 struct pwm_device **ptr, *pwm;
717 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
718 if (!ptr)
719 return ERR_PTR(-ENOMEM);
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);
729 return pwm;
731 EXPORT_SYMBOL_GPL(devm_pwm_get);
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
739 * This function performs like of_pwm_get() but the acquired PWM device will
740 * automatically be released on driver detach.
742 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
743 const char *con_id)
745 struct pwm_device **ptr, *pwm;
747 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
748 if (!ptr)
749 return ERR_PTR(-ENOMEM);
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);
759 return pwm;
761 EXPORT_SYMBOL_GPL(devm_of_pwm_get);
763 static int devm_pwm_match(struct device *dev, void *res, void *data)
765 struct pwm_device **p = res;
767 if (WARN_ON(!p || !*p))
768 return 0;
770 return *p == data;
774 * devm_pwm_put() - resource managed pwm_put()
775 * @dev: device for PWM consumer
776 * @pwm: PWM device
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.
782 void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
784 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
786 EXPORT_SYMBOL_GPL(devm_pwm_put);
789 * pwm_can_sleep() - report whether PWM access will sleep
790 * @pwm: PWM device
792 * It returns true if accessing the PWM can sleep, false otherwise.
794 bool pwm_can_sleep(struct pwm_device *pwm)
796 return pwm->chip->can_sleep;
798 EXPORT_SYMBOL_GPL(pwm_can_sleep);
800 #ifdef CONFIG_DEBUG_FS
801 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
803 unsigned int i;
805 for (i = 0; i < chip->npwm; i++) {
806 struct pwm_device *pwm = &chip->pwms[i];
808 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
810 if (test_bit(PWMF_REQUESTED, &pwm->flags))
811 seq_puts(s, " requested");
813 if (test_bit(PWMF_ENABLED, &pwm->flags))
814 seq_puts(s, " enabled");
816 seq_puts(s, "\n");
820 static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
822 mutex_lock(&pwm_lock);
823 s->private = "";
825 return seq_list_start(&pwm_chips, *pos);
828 static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
830 s->private = "\n";
832 return seq_list_next(v, &pwm_chips, pos);
835 static void pwm_seq_stop(struct seq_file *s, void *v)
837 mutex_unlock(&pwm_lock);
840 static int pwm_seq_show(struct seq_file *s, void *v)
842 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
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" : "");
849 if (chip->ops->dbg_show)
850 chip->ops->dbg_show(chip, s);
851 else
852 pwm_dbg_show(chip, s);
854 return 0;
857 static 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,
864 static int pwm_seq_open(struct inode *inode, struct file *file)
866 return seq_open(file, &pwm_seq_ops);
869 static 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,
877 static int __init pwm_debugfs_init(void)
879 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
880 &pwm_debugfs_ops);
882 return 0;
885 subsys_initcall(pwm_debugfs_init);
886 #endif /* CONFIG_DEBUG_FS */