xfs: create internal eofblocks structure with kuid_t types
[linux-2.6.git] / drivers / pwm / core.c
blobdfbfbc5217683de697d1c834f73c55de0ff850de
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 #define MAX_PWMS 1024
35 /* flags in the third cell of the DT PWM specifier */
36 #define PWM_SPEC_POLARITY (1 << 0)
38 static DEFINE_MUTEX(pwm_lookup_lock);
39 static LIST_HEAD(pwm_lookup_list);
40 static DEFINE_MUTEX(pwm_lock);
41 static LIST_HEAD(pwm_chips);
42 static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
43 static RADIX_TREE(pwm_tree, GFP_KERNEL);
45 static struct pwm_device *pwm_to_device(unsigned int pwm)
47 return radix_tree_lookup(&pwm_tree, pwm);
50 static int alloc_pwms(int pwm, unsigned int count)
52 unsigned int from = 0;
53 unsigned int start;
55 if (pwm >= MAX_PWMS)
56 return -EINVAL;
58 if (pwm >= 0)
59 from = pwm;
61 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
62 count, 0);
64 if (pwm >= 0 && start != pwm)
65 return -EEXIST;
67 if (start + count > MAX_PWMS)
68 return -ENOSPC;
70 return start;
73 static void free_pwms(struct pwm_chip *chip)
75 unsigned int i;
77 for (i = 0; i < chip->npwm; i++) {
78 struct pwm_device *pwm = &chip->pwms[i];
79 radix_tree_delete(&pwm_tree, pwm->pwm);
82 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
84 kfree(chip->pwms);
85 chip->pwms = NULL;
88 static struct pwm_chip *pwmchip_find_by_name(const char *name)
90 struct pwm_chip *chip;
92 if (!name)
93 return NULL;
95 mutex_lock(&pwm_lock);
97 list_for_each_entry(chip, &pwm_chips, list) {
98 const char *chip_name = dev_name(chip->dev);
100 if (chip_name && strcmp(chip_name, name) == 0) {
101 mutex_unlock(&pwm_lock);
102 return chip;
106 mutex_unlock(&pwm_lock);
108 return NULL;
111 static int pwm_device_request(struct pwm_device *pwm, const char *label)
113 int err;
115 if (test_bit(PWMF_REQUESTED, &pwm->flags))
116 return -EBUSY;
118 if (!try_module_get(pwm->chip->ops->owner))
119 return -ENODEV;
121 if (pwm->chip->ops->request) {
122 err = pwm->chip->ops->request(pwm->chip, pwm);
123 if (err) {
124 module_put(pwm->chip->ops->owner);
125 return err;
129 set_bit(PWMF_REQUESTED, &pwm->flags);
130 pwm->label = label;
132 return 0;
135 struct pwm_device *
136 of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
138 struct pwm_device *pwm;
140 if (pc->of_pwm_n_cells < 3)
141 return ERR_PTR(-EINVAL);
143 if (args->args[0] >= pc->npwm)
144 return ERR_PTR(-EINVAL);
146 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
147 if (IS_ERR(pwm))
148 return pwm;
150 pwm_set_period(pwm, args->args[1]);
152 if (args->args[2] & PWM_SPEC_POLARITY)
153 pwm_set_polarity(pwm, PWM_POLARITY_INVERSED);
154 else
155 pwm_set_polarity(pwm, PWM_POLARITY_NORMAL);
157 return pwm;
159 EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
161 static struct pwm_device *
162 of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
164 struct pwm_device *pwm;
166 if (pc->of_pwm_n_cells < 2)
167 return ERR_PTR(-EINVAL);
169 if (args->args[0] >= pc->npwm)
170 return ERR_PTR(-EINVAL);
172 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
173 if (IS_ERR(pwm))
174 return pwm;
176 pwm_set_period(pwm, args->args[1]);
178 return pwm;
181 static void of_pwmchip_add(struct pwm_chip *chip)
183 if (!chip->dev || !chip->dev->of_node)
184 return;
186 if (!chip->of_xlate) {
187 chip->of_xlate = of_pwm_simple_xlate;
188 chip->of_pwm_n_cells = 2;
191 of_node_get(chip->dev->of_node);
194 static void of_pwmchip_remove(struct pwm_chip *chip)
196 if (chip->dev && chip->dev->of_node)
197 of_node_put(chip->dev->of_node);
201 * pwm_set_chip_data() - set private chip data for a PWM
202 * @pwm: PWM device
203 * @data: pointer to chip-specific data
205 int pwm_set_chip_data(struct pwm_device *pwm, void *data)
207 if (!pwm)
208 return -EINVAL;
210 pwm->chip_data = data;
212 return 0;
214 EXPORT_SYMBOL_GPL(pwm_set_chip_data);
217 * pwm_get_chip_data() - get private chip data for a PWM
218 * @pwm: PWM device
220 void *pwm_get_chip_data(struct pwm_device *pwm)
222 return pwm ? pwm->chip_data : NULL;
224 EXPORT_SYMBOL_GPL(pwm_get_chip_data);
227 * pwmchip_add() - register a new PWM chip
228 * @chip: the PWM chip to add
230 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
231 * will be used.
233 int pwmchip_add(struct pwm_chip *chip)
235 struct pwm_device *pwm;
236 unsigned int i;
237 int ret;
239 if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
240 !chip->ops->enable || !chip->ops->disable)
241 return -EINVAL;
243 mutex_lock(&pwm_lock);
245 ret = alloc_pwms(chip->base, chip->npwm);
246 if (ret < 0)
247 goto out;
249 chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL);
250 if (!chip->pwms) {
251 ret = -ENOMEM;
252 goto out;
255 chip->base = ret;
257 for (i = 0; i < chip->npwm; i++) {
258 pwm = &chip->pwms[i];
260 pwm->chip = chip;
261 pwm->pwm = chip->base + i;
262 pwm->hwpwm = i;
264 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
267 bitmap_set(allocated_pwms, chip->base, chip->npwm);
269 INIT_LIST_HEAD(&chip->list);
270 list_add(&chip->list, &pwm_chips);
272 ret = 0;
274 if (IS_ENABLED(CONFIG_OF))
275 of_pwmchip_add(chip);
277 pwmchip_sysfs_export(chip);
279 out:
280 mutex_unlock(&pwm_lock);
281 return ret;
283 EXPORT_SYMBOL_GPL(pwmchip_add);
286 * pwmchip_remove() - remove a PWM chip
287 * @chip: the PWM chip to remove
289 * Removes a PWM chip. This function may return busy if the PWM chip provides
290 * a PWM device that is still requested.
292 int pwmchip_remove(struct pwm_chip *chip)
294 unsigned int i;
295 int ret = 0;
297 mutex_lock(&pwm_lock);
299 for (i = 0; i < chip->npwm; i++) {
300 struct pwm_device *pwm = &chip->pwms[i];
302 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
303 ret = -EBUSY;
304 goto out;
308 list_del_init(&chip->list);
310 if (IS_ENABLED(CONFIG_OF))
311 of_pwmchip_remove(chip);
313 free_pwms(chip);
315 pwmchip_sysfs_unexport(chip);
317 out:
318 mutex_unlock(&pwm_lock);
319 return ret;
321 EXPORT_SYMBOL_GPL(pwmchip_remove);
324 * pwm_request() - request a PWM device
325 * @pwm_id: global PWM device index
326 * @label: PWM device label
328 * This function is deprecated, use pwm_get() instead.
330 struct pwm_device *pwm_request(int pwm, const char *label)
332 struct pwm_device *dev;
333 int err;
335 if (pwm < 0 || pwm >= MAX_PWMS)
336 return ERR_PTR(-EINVAL);
338 mutex_lock(&pwm_lock);
340 dev = pwm_to_device(pwm);
341 if (!dev) {
342 dev = ERR_PTR(-EPROBE_DEFER);
343 goto out;
346 err = pwm_device_request(dev, label);
347 if (err < 0)
348 dev = ERR_PTR(err);
350 out:
351 mutex_unlock(&pwm_lock);
353 return dev;
355 EXPORT_SYMBOL_GPL(pwm_request);
358 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
359 * @chip: PWM chip
360 * @index: per-chip index of the PWM to request
361 * @label: a literal description string of this PWM
363 * Returns the PWM at the given index of the given PWM chip. A negative error
364 * code is returned if the index is not valid for the specified PWM chip or
365 * if the PWM device cannot be requested.
367 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
368 unsigned int index,
369 const char *label)
371 struct pwm_device *pwm;
372 int err;
374 if (!chip || index >= chip->npwm)
375 return ERR_PTR(-EINVAL);
377 mutex_lock(&pwm_lock);
378 pwm = &chip->pwms[index];
380 err = pwm_device_request(pwm, label);
381 if (err < 0)
382 pwm = ERR_PTR(err);
384 mutex_unlock(&pwm_lock);
385 return pwm;
387 EXPORT_SYMBOL_GPL(pwm_request_from_chip);
390 * pwm_free() - free a PWM device
391 * @pwm: PWM device
393 * This function is deprecated, use pwm_put() instead.
395 void pwm_free(struct pwm_device *pwm)
397 pwm_put(pwm);
399 EXPORT_SYMBOL_GPL(pwm_free);
402 * pwm_config() - change a PWM device configuration
403 * @pwm: PWM device
404 * @duty_ns: "on" time (in nanoseconds)
405 * @period_ns: duration (in nanoseconds) of one cycle
407 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
409 int err;
411 if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
412 return -EINVAL;
414 err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
415 if (err)
416 return err;
418 pwm->duty_cycle = duty_ns;
419 pwm->period = period_ns;
421 return 0;
423 EXPORT_SYMBOL_GPL(pwm_config);
426 * pwm_set_polarity() - configure the polarity of a PWM signal
427 * @pwm: PWM device
428 * @polarity: new polarity of the PWM signal
430 * Note that the polarity cannot be configured while the PWM device is enabled
432 int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
434 int err;
436 if (!pwm || !pwm->chip->ops)
437 return -EINVAL;
439 if (!pwm->chip->ops->set_polarity)
440 return -ENOSYS;
442 if (test_bit(PWMF_ENABLED, &pwm->flags))
443 return -EBUSY;
445 err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
446 if (err)
447 return err;
449 pwm->polarity = polarity;
451 return 0;
453 EXPORT_SYMBOL_GPL(pwm_set_polarity);
456 * pwm_enable() - start a PWM output toggling
457 * @pwm: PWM device
459 int pwm_enable(struct pwm_device *pwm)
461 if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags))
462 return pwm->chip->ops->enable(pwm->chip, pwm);
464 return pwm ? 0 : -EINVAL;
466 EXPORT_SYMBOL_GPL(pwm_enable);
469 * pwm_disable() - stop a PWM output toggling
470 * @pwm: PWM device
472 void pwm_disable(struct pwm_device *pwm)
474 if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
475 pwm->chip->ops->disable(pwm->chip, pwm);
477 EXPORT_SYMBOL_GPL(pwm_disable);
479 static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
481 struct pwm_chip *chip;
483 mutex_lock(&pwm_lock);
485 list_for_each_entry(chip, &pwm_chips, list)
486 if (chip->dev && chip->dev->of_node == np) {
487 mutex_unlock(&pwm_lock);
488 return chip;
491 mutex_unlock(&pwm_lock);
493 return ERR_PTR(-EPROBE_DEFER);
497 * of_pwm_get() - request a PWM via the PWM framework
498 * @np: device node to get the PWM from
499 * @con_id: consumer name
501 * Returns the PWM device parsed from the phandle and index specified in the
502 * "pwms" property of a device tree node or a negative error-code on failure.
503 * Values parsed from the device tree are stored in the returned PWM device
504 * object.
506 * If con_id is NULL, the first PWM device listed in the "pwms" property will
507 * be requested. Otherwise the "pwm-names" property is used to do a reverse
508 * lookup of the PWM index. This also means that the "pwm-names" property
509 * becomes mandatory for devices that look up the PWM device via the con_id
510 * parameter.
512 struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
514 struct pwm_device *pwm = NULL;
515 struct of_phandle_args args;
516 struct pwm_chip *pc;
517 int index = 0;
518 int err;
520 if (con_id) {
521 index = of_property_match_string(np, "pwm-names", con_id);
522 if (index < 0)
523 return ERR_PTR(index);
526 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
527 &args);
528 if (err) {
529 pr_debug("%s(): can't parse \"pwms\" property\n", __func__);
530 return ERR_PTR(err);
533 pc = of_node_to_pwmchip(args.np);
534 if (IS_ERR(pc)) {
535 pr_debug("%s(): PWM chip not found\n", __func__);
536 pwm = ERR_CAST(pc);
537 goto put;
540 if (args.args_count != pc->of_pwm_n_cells) {
541 pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name,
542 args.np->full_name);
543 pwm = ERR_PTR(-EINVAL);
544 goto put;
547 pwm = pc->of_xlate(pc, &args);
548 if (IS_ERR(pwm))
549 goto put;
552 * If a consumer name was not given, try to look it up from the
553 * "pwm-names" property if it exists. Otherwise use the name of
554 * the user device node.
556 if (!con_id) {
557 err = of_property_read_string_index(np, "pwm-names", index,
558 &con_id);
559 if (err < 0)
560 con_id = np->name;
563 pwm->label = con_id;
565 put:
566 of_node_put(args.np);
568 return pwm;
570 EXPORT_SYMBOL_GPL(of_pwm_get);
573 * pwm_add_table() - register PWM device consumers
574 * @table: array of consumers to register
575 * @num: number of consumers in table
577 void __init pwm_add_table(struct pwm_lookup *table, size_t num)
579 mutex_lock(&pwm_lookup_lock);
581 while (num--) {
582 list_add_tail(&table->list, &pwm_lookup_list);
583 table++;
586 mutex_unlock(&pwm_lookup_lock);
590 * pwm_get() - look up and request a PWM device
591 * @dev: device for PWM consumer
592 * @con_id: consumer name
594 * Lookup is first attempted using DT. If the device was not instantiated from
595 * a device tree, a PWM chip and a relative index is looked up via a table
596 * supplied by board setup code (see pwm_add_table()).
598 * Once a PWM chip has been found the specified PWM device will be requested
599 * and is ready to be used.
601 struct pwm_device *pwm_get(struct device *dev, const char *con_id)
603 struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER);
604 const char *dev_id = dev ? dev_name(dev) : NULL;
605 struct pwm_chip *chip = NULL;
606 unsigned int index = 0;
607 unsigned int best = 0;
608 struct pwm_lookup *p;
609 unsigned int match;
611 /* look up via DT first */
612 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
613 return of_pwm_get(dev->of_node, con_id);
616 * We look up the provider in the static table typically provided by
617 * board setup code. We first try to lookup the consumer device by
618 * name. If the consumer device was passed in as NULL or if no match
619 * was found, we try to find the consumer by directly looking it up
620 * by name.
622 * If a match is found, the provider PWM chip is looked up by name
623 * and a PWM device is requested using the PWM device per-chip index.
625 * The lookup algorithm was shamelessly taken from the clock
626 * framework:
628 * We do slightly fuzzy matching here:
629 * An entry with a NULL ID is assumed to be a wildcard.
630 * If an entry has a device ID, it must match
631 * If an entry has a connection ID, it must match
632 * Then we take the most specific entry - with the following order
633 * of precedence: dev+con > dev only > con only.
635 mutex_lock(&pwm_lookup_lock);
637 list_for_each_entry(p, &pwm_lookup_list, list) {
638 match = 0;
640 if (p->dev_id) {
641 if (!dev_id || strcmp(p->dev_id, dev_id))
642 continue;
644 match += 2;
647 if (p->con_id) {
648 if (!con_id || strcmp(p->con_id, con_id))
649 continue;
651 match += 1;
654 if (match > best) {
655 chip = pwmchip_find_by_name(p->provider);
656 index = p->index;
658 if (match != 3)
659 best = match;
660 else
661 break;
665 if (chip)
666 pwm = pwm_request_from_chip(chip, index, con_id ?: dev_id);
668 mutex_unlock(&pwm_lookup_lock);
670 return pwm;
672 EXPORT_SYMBOL_GPL(pwm_get);
675 * pwm_put() - release a PWM device
676 * @pwm: PWM device
678 void pwm_put(struct pwm_device *pwm)
680 if (!pwm)
681 return;
683 mutex_lock(&pwm_lock);
685 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
686 pr_warn("PWM device already freed\n");
687 goto out;
690 if (pwm->chip->ops->free)
691 pwm->chip->ops->free(pwm->chip, pwm);
693 pwm->label = NULL;
695 module_put(pwm->chip->ops->owner);
696 out:
697 mutex_unlock(&pwm_lock);
699 EXPORT_SYMBOL_GPL(pwm_put);
701 static void devm_pwm_release(struct device *dev, void *res)
703 pwm_put(*(struct pwm_device **)res);
707 * devm_pwm_get() - resource managed pwm_get()
708 * @dev: device for PWM consumer
709 * @con_id: consumer name
711 * This function performs like pwm_get() but the acquired PWM device will
712 * automatically be released on driver detach.
714 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
716 struct pwm_device **ptr, *pwm;
718 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
719 if (!ptr)
720 return ERR_PTR(-ENOMEM);
722 pwm = pwm_get(dev, con_id);
723 if (!IS_ERR(pwm)) {
724 *ptr = pwm;
725 devres_add(dev, ptr);
726 } else {
727 devres_free(ptr);
730 return pwm;
732 EXPORT_SYMBOL_GPL(devm_pwm_get);
735 * devm_of_pwm_get() - resource managed of_pwm_get()
736 * @dev: device for PWM consumer
737 * @np: device node to get the PWM from
738 * @con_id: consumer name
740 * This function performs like of_pwm_get() but the acquired PWM device will
741 * automatically be released on driver detach.
743 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
744 const char *con_id)
746 struct pwm_device **ptr, *pwm;
748 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
749 if (!ptr)
750 return ERR_PTR(-ENOMEM);
752 pwm = of_pwm_get(np, con_id);
753 if (!IS_ERR(pwm)) {
754 *ptr = pwm;
755 devres_add(dev, ptr);
756 } else {
757 devres_free(ptr);
760 return pwm;
762 EXPORT_SYMBOL_GPL(devm_of_pwm_get);
764 static int devm_pwm_match(struct device *dev, void *res, void *data)
766 struct pwm_device **p = res;
768 if (WARN_ON(!p || !*p))
769 return 0;
771 return *p == data;
775 * devm_pwm_put() - resource managed pwm_put()
776 * @dev: device for PWM consumer
777 * @pwm: PWM device
779 * Release a PWM previously allocated using devm_pwm_get(). Calling this
780 * function is usually not needed because devm-allocated resources are
781 * automatically released on driver detach.
783 void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
785 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
787 EXPORT_SYMBOL_GPL(devm_pwm_put);
790 * pwm_can_sleep() - report whether PWM access will sleep
791 * @pwm: PWM device
793 * It returns true if accessing the PWM can sleep, false otherwise.
795 bool pwm_can_sleep(struct pwm_device *pwm)
797 return pwm->chip->can_sleep;
799 EXPORT_SYMBOL_GPL(pwm_can_sleep);
801 #ifdef CONFIG_DEBUG_FS
802 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
804 unsigned int i;
806 for (i = 0; i < chip->npwm; i++) {
807 struct pwm_device *pwm = &chip->pwms[i];
809 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
811 if (test_bit(PWMF_REQUESTED, &pwm->flags))
812 seq_printf(s, " requested");
814 if (test_bit(PWMF_ENABLED, &pwm->flags))
815 seq_printf(s, " enabled");
817 seq_printf(s, "\n");
821 static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
823 mutex_lock(&pwm_lock);
824 s->private = "";
826 return seq_list_start(&pwm_chips, *pos);
829 static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
831 s->private = "\n";
833 return seq_list_next(v, &pwm_chips, pos);
836 static void pwm_seq_stop(struct seq_file *s, void *v)
838 mutex_unlock(&pwm_lock);
841 static int pwm_seq_show(struct seq_file *s, void *v)
843 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
845 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
846 chip->dev->bus ? chip->dev->bus->name : "no-bus",
847 dev_name(chip->dev), chip->npwm,
848 (chip->npwm != 1) ? "s" : "");
850 if (chip->ops->dbg_show)
851 chip->ops->dbg_show(chip, s);
852 else
853 pwm_dbg_show(chip, s);
855 return 0;
858 static const struct seq_operations pwm_seq_ops = {
859 .start = pwm_seq_start,
860 .next = pwm_seq_next,
861 .stop = pwm_seq_stop,
862 .show = pwm_seq_show,
865 static int pwm_seq_open(struct inode *inode, struct file *file)
867 return seq_open(file, &pwm_seq_ops);
870 static const struct file_operations pwm_debugfs_ops = {
871 .owner = THIS_MODULE,
872 .open = pwm_seq_open,
873 .read = seq_read,
874 .llseek = seq_lseek,
875 .release = seq_release,
878 static int __init pwm_debugfs_init(void)
880 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
881 &pwm_debugfs_ops);
883 return 0;
886 subsys_initcall(pwm_debugfs_init);
887 #endif /* CONFIG_DEBUG_FS */