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)
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>
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;
60 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
63 if (pwm >= 0 && start != pwm)
66 if (start + count > MAX_PWMS)
72 static void free_pwms(struct pwm_chip *chip)
76 for (i = 0; i < chip->npwm; i++) {
77 struct pwm_device *pwm = &chip->pwms[i];
79 radix_tree_delete(&pwm_tree, pwm->pwm);
82 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
88 static struct pwm_chip *pwmchip_find_by_name(const char *name)
90 struct pwm_chip *chip;
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);
106 mutex_unlock(&pwm_lock);
111 static int pwm_device_request(struct pwm_device *pwm, const char *label)
115 if (test_bit(PWMF_REQUESTED, &pwm->flags))
118 if (!try_module_get(pwm->chip->ops->owner))
121 if (pwm->chip->ops->request) {
122 err = pwm->chip->ops->request(pwm->chip, pwm);
124 module_put(pwm->chip->ops->owner);
129 set_bit(PWMF_REQUESTED, &pwm->flags);
136 of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
138 struct pwm_device *pwm;
140 /* check, whether the driver supports a third cell for flags */
141 if (pc->of_pwm_n_cells < 3)
142 return ERR_PTR(-EINVAL);
144 /* flags in the third cell are optional */
145 if (args->args_count < 2)
146 return ERR_PTR(-EINVAL);
148 if (args->args[0] >= pc->npwm)
149 return ERR_PTR(-EINVAL);
151 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
155 pwm->args.period = args->args[1];
156 pwm->args.polarity = PWM_POLARITY_NORMAL;
158 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
159 pwm->args.polarity = PWM_POLARITY_INVERSED;
163 EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
165 static struct pwm_device *
166 of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
168 struct pwm_device *pwm;
170 /* sanity check driver support */
171 if (pc->of_pwm_n_cells < 2)
172 return ERR_PTR(-EINVAL);
174 /* all cells are required */
175 if (args->args_count != pc->of_pwm_n_cells)
176 return ERR_PTR(-EINVAL);
178 if (args->args[0] >= pc->npwm)
179 return ERR_PTR(-EINVAL);
181 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
185 pwm->args.period = args->args[1];
190 static void of_pwmchip_add(struct pwm_chip *chip)
192 if (!chip->dev || !chip->dev->of_node)
195 if (!chip->of_xlate) {
196 chip->of_xlate = of_pwm_simple_xlate;
197 chip->of_pwm_n_cells = 2;
200 of_node_get(chip->dev->of_node);
203 static void of_pwmchip_remove(struct pwm_chip *chip)
206 of_node_put(chip->dev->of_node);
210 * pwm_set_chip_data() - set private chip data for a PWM
212 * @data: pointer to chip-specific data
214 * Returns: 0 on success or a negative error code on failure.
216 int pwm_set_chip_data(struct pwm_device *pwm, void *data)
221 pwm->chip_data = data;
225 EXPORT_SYMBOL_GPL(pwm_set_chip_data);
228 * pwm_get_chip_data() - get private chip data for a PWM
231 * Returns: A pointer to the chip-private data for the PWM device.
233 void *pwm_get_chip_data(struct pwm_device *pwm)
235 return pwm ? pwm->chip_data : NULL;
237 EXPORT_SYMBOL_GPL(pwm_get_chip_data);
239 static bool pwm_ops_check(const struct pwm_ops *ops)
241 /* driver supports legacy, non-atomic operation */
242 if (ops->config && ops->enable && ops->disable)
245 /* driver supports atomic operation */
253 * pwmchip_add_with_polarity() - register a new PWM chip
254 * @chip: the PWM chip to add
255 * @polarity: initial polarity of PWM channels
257 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
258 * will be used. The initial polarity for all channels is specified by the
259 * @polarity parameter.
261 * Returns: 0 on success or a negative error code on failure.
263 int pwmchip_add_with_polarity(struct pwm_chip *chip,
264 enum pwm_polarity polarity)
266 struct pwm_device *pwm;
270 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
273 if (!pwm_ops_check(chip->ops))
276 mutex_lock(&pwm_lock);
278 ret = alloc_pwms(chip->base, chip->npwm);
282 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
290 for (i = 0; i < chip->npwm; i++) {
291 pwm = &chip->pwms[i];
294 pwm->pwm = chip->base + i;
296 pwm->state.polarity = polarity;
298 if (chip->ops->get_state)
299 chip->ops->get_state(chip, pwm, &pwm->state);
301 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
304 bitmap_set(allocated_pwms, chip->base, chip->npwm);
306 INIT_LIST_HEAD(&chip->list);
307 list_add(&chip->list, &pwm_chips);
311 if (IS_ENABLED(CONFIG_OF))
312 of_pwmchip_add(chip);
314 pwmchip_sysfs_export(chip);
317 mutex_unlock(&pwm_lock);
320 EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity);
323 * pwmchip_add() - register a new PWM chip
324 * @chip: the PWM chip to add
326 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
327 * will be used. The initial polarity for all channels is normal.
329 * Returns: 0 on success or a negative error code on failure.
331 int pwmchip_add(struct pwm_chip *chip)
333 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
335 EXPORT_SYMBOL_GPL(pwmchip_add);
338 * pwmchip_remove() - remove a PWM chip
339 * @chip: the PWM chip to remove
341 * Removes a PWM chip. This function may return busy if the PWM chip provides
342 * a PWM device that is still requested.
344 * Returns: 0 on success or a negative error code on failure.
346 int pwmchip_remove(struct pwm_chip *chip)
351 pwmchip_sysfs_unexport_children(chip);
353 mutex_lock(&pwm_lock);
355 for (i = 0; i < chip->npwm; i++) {
356 struct pwm_device *pwm = &chip->pwms[i];
358 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
364 list_del_init(&chip->list);
366 if (IS_ENABLED(CONFIG_OF))
367 of_pwmchip_remove(chip);
371 pwmchip_sysfs_unexport(chip);
374 mutex_unlock(&pwm_lock);
377 EXPORT_SYMBOL_GPL(pwmchip_remove);
380 * pwm_request() - request a PWM device
381 * @pwm: global PWM device index
382 * @label: PWM device label
384 * This function is deprecated, use pwm_get() instead.
386 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
389 struct pwm_device *pwm_request(int pwm, const char *label)
391 struct pwm_device *dev;
394 if (pwm < 0 || pwm >= MAX_PWMS)
395 return ERR_PTR(-EINVAL);
397 mutex_lock(&pwm_lock);
399 dev = pwm_to_device(pwm);
401 dev = ERR_PTR(-EPROBE_DEFER);
405 err = pwm_device_request(dev, label);
410 mutex_unlock(&pwm_lock);
414 EXPORT_SYMBOL_GPL(pwm_request);
417 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
419 * @index: per-chip index of the PWM to request
420 * @label: a literal description string of this PWM
422 * Returns: A pointer to the PWM device at the given index of the given PWM
423 * chip. A negative error code is returned if the index is not valid for the
424 * specified PWM chip or if the PWM device cannot be requested.
426 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
430 struct pwm_device *pwm;
433 if (!chip || index >= chip->npwm)
434 return ERR_PTR(-EINVAL);
436 mutex_lock(&pwm_lock);
437 pwm = &chip->pwms[index];
439 err = pwm_device_request(pwm, label);
443 mutex_unlock(&pwm_lock);
446 EXPORT_SYMBOL_GPL(pwm_request_from_chip);
449 * pwm_free() - free a PWM device
452 * This function is deprecated, use pwm_put() instead.
454 void pwm_free(struct pwm_device *pwm)
458 EXPORT_SYMBOL_GPL(pwm_free);
461 * pwm_apply_state() - atomically apply a new state to a PWM device
463 * @state: new state to apply. This can be adjusted by the PWM driver
464 * if the requested config is not achievable, for example,
465 * ->duty_cycle and ->period might be approximated.
467 int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state)
471 if (!pwm || !state || !state->period ||
472 state->duty_cycle > state->period)
475 if (state->period == pwm->state.period &&
476 state->duty_cycle == pwm->state.duty_cycle &&
477 state->polarity == pwm->state.polarity &&
478 state->enabled == pwm->state.enabled)
481 if (pwm->chip->ops->apply) {
482 err = pwm->chip->ops->apply(pwm->chip, pwm, state);
489 * FIXME: restore the initial state in case of error.
491 if (state->polarity != pwm->state.polarity) {
492 if (!pwm->chip->ops->set_polarity)
496 * Changing the polarity of a running PWM is
497 * only allowed when the PWM driver implements
500 if (pwm->state.enabled) {
501 pwm->chip->ops->disable(pwm->chip, pwm);
502 pwm->state.enabled = false;
505 err = pwm->chip->ops->set_polarity(pwm->chip, pwm,
510 pwm->state.polarity = state->polarity;
513 if (state->period != pwm->state.period ||
514 state->duty_cycle != pwm->state.duty_cycle) {
515 err = pwm->chip->ops->config(pwm->chip, pwm,
521 pwm->state.duty_cycle = state->duty_cycle;
522 pwm->state.period = state->period;
525 if (state->enabled != pwm->state.enabled) {
526 if (state->enabled) {
527 err = pwm->chip->ops->enable(pwm->chip, pwm);
531 pwm->chip->ops->disable(pwm->chip, pwm);
534 pwm->state.enabled = state->enabled;
540 EXPORT_SYMBOL_GPL(pwm_apply_state);
543 * pwm_capture() - capture and report a PWM signal
545 * @result: structure to fill with capture result
546 * @timeout: time to wait, in milliseconds, before giving up on capture
548 * Returns: 0 on success or a negative error code on failure.
550 int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
551 unsigned long timeout)
555 if (!pwm || !pwm->chip->ops)
558 if (!pwm->chip->ops->capture)
561 mutex_lock(&pwm_lock);
562 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
563 mutex_unlock(&pwm_lock);
567 EXPORT_SYMBOL_GPL(pwm_capture);
570 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
573 * This function will adjust the PWM config to the PWM arguments provided
574 * by the DT or PWM lookup table. This is particularly useful to adapt
575 * the bootloader config to the Linux one.
577 int pwm_adjust_config(struct pwm_device *pwm)
579 struct pwm_state state;
580 struct pwm_args pargs;
582 pwm_get_args(pwm, &pargs);
583 pwm_get_state(pwm, &state);
586 * If the current period is zero it means that either the PWM driver
587 * does not support initial state retrieval or the PWM has not yet
590 * In either case, we setup the new period and polarity, and assign a
594 state.duty_cycle = 0;
595 state.period = pargs.period;
596 state.polarity = pargs.polarity;
598 return pwm_apply_state(pwm, &state);
602 * Adjust the PWM duty cycle/period based on the period value provided
605 if (pargs.period != state.period) {
606 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
608 do_div(dutycycle, state.period);
609 state.duty_cycle = dutycycle;
610 state.period = pargs.period;
614 * If the polarity changed, we should also change the duty cycle.
616 if (pargs.polarity != state.polarity) {
617 state.polarity = pargs.polarity;
618 state.duty_cycle = state.period - state.duty_cycle;
621 return pwm_apply_state(pwm, &state);
623 EXPORT_SYMBOL_GPL(pwm_adjust_config);
625 static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
627 struct pwm_chip *chip;
629 mutex_lock(&pwm_lock);
631 list_for_each_entry(chip, &pwm_chips, list)
632 if (chip->dev && chip->dev->of_node == np) {
633 mutex_unlock(&pwm_lock);
637 mutex_unlock(&pwm_lock);
639 return ERR_PTR(-EPROBE_DEFER);
643 * of_pwm_get() - request a PWM via the PWM framework
644 * @np: device node to get the PWM from
645 * @con_id: consumer name
647 * Returns the PWM device parsed from the phandle and index specified in the
648 * "pwms" property of a device tree node or a negative error-code on failure.
649 * Values parsed from the device tree are stored in the returned PWM device
652 * If con_id is NULL, the first PWM device listed in the "pwms" property will
653 * be requested. Otherwise the "pwm-names" property is used to do a reverse
654 * lookup of the PWM index. This also means that the "pwm-names" property
655 * becomes mandatory for devices that look up the PWM device via the con_id
658 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
659 * error code on failure.
661 struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
663 struct pwm_device *pwm = NULL;
664 struct of_phandle_args args;
670 index = of_property_match_string(np, "pwm-names", con_id);
672 return ERR_PTR(index);
675 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
678 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
682 pc = of_node_to_pwmchip(args.np);
684 if (PTR_ERR(pc) != -EPROBE_DEFER)
685 pr_err("%s(): PWM chip not found\n", __func__);
691 pwm = pc->of_xlate(pc, &args);
696 * If a consumer name was not given, try to look it up from the
697 * "pwm-names" property if it exists. Otherwise use the name of
698 * the user device node.
701 err = of_property_read_string_index(np, "pwm-names", index,
710 of_node_put(args.np);
714 EXPORT_SYMBOL_GPL(of_pwm_get);
717 * pwm_add_table() - register PWM device consumers
718 * @table: array of consumers to register
719 * @num: number of consumers in table
721 void pwm_add_table(struct pwm_lookup *table, size_t num)
723 mutex_lock(&pwm_lookup_lock);
726 list_add_tail(&table->list, &pwm_lookup_list);
730 mutex_unlock(&pwm_lookup_lock);
734 * pwm_remove_table() - unregister PWM device consumers
735 * @table: array of consumers to unregister
736 * @num: number of consumers in table
738 void pwm_remove_table(struct pwm_lookup *table, size_t num)
740 mutex_lock(&pwm_lookup_lock);
743 list_del(&table->list);
747 mutex_unlock(&pwm_lookup_lock);
751 * pwm_get() - look up and request a PWM device
752 * @dev: device for PWM consumer
753 * @con_id: consumer name
755 * Lookup is first attempted using DT. If the device was not instantiated from
756 * a device tree, a PWM chip and a relative index is looked up via a table
757 * supplied by board setup code (see pwm_add_table()).
759 * Once a PWM chip has been found the specified PWM device will be requested
760 * and is ready to be used.
762 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
763 * error code on failure.
765 struct pwm_device *pwm_get(struct device *dev, const char *con_id)
767 const char *dev_id = dev ? dev_name(dev) : NULL;
768 struct pwm_device *pwm;
769 struct pwm_chip *chip;
770 unsigned int best = 0;
771 struct pwm_lookup *p, *chosen = NULL;
775 /* look up via DT first */
776 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
777 return of_pwm_get(dev->of_node, con_id);
780 * We look up the provider in the static table typically provided by
781 * board setup code. We first try to lookup the consumer device by
782 * name. If the consumer device was passed in as NULL or if no match
783 * was found, we try to find the consumer by directly looking it up
786 * If a match is found, the provider PWM chip is looked up by name
787 * and a PWM device is requested using the PWM device per-chip index.
789 * The lookup algorithm was shamelessly taken from the clock
792 * We do slightly fuzzy matching here:
793 * An entry with a NULL ID is assumed to be a wildcard.
794 * If an entry has a device ID, it must match
795 * If an entry has a connection ID, it must match
796 * Then we take the most specific entry - with the following order
797 * of precedence: dev+con > dev only > con only.
799 mutex_lock(&pwm_lookup_lock);
801 list_for_each_entry(p, &pwm_lookup_list, list) {
805 if (!dev_id || strcmp(p->dev_id, dev_id))
812 if (!con_id || strcmp(p->con_id, con_id))
828 mutex_unlock(&pwm_lookup_lock);
831 return ERR_PTR(-ENODEV);
833 chip = pwmchip_find_by_name(chosen->provider);
836 * If the lookup entry specifies a module, load the module and retry
837 * the PWM chip lookup. This can be used to work around driver load
838 * ordering issues if driver's can't be made to properly support the
839 * deferred probe mechanism.
841 if (!chip && chosen->module) {
842 err = request_module(chosen->module);
844 chip = pwmchip_find_by_name(chosen->provider);
848 return ERR_PTR(-EPROBE_DEFER);
850 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
854 pwm->args.period = chosen->period;
855 pwm->args.polarity = chosen->polarity;
859 EXPORT_SYMBOL_GPL(pwm_get);
862 * pwm_put() - release a PWM device
865 void pwm_put(struct pwm_device *pwm)
870 mutex_lock(&pwm_lock);
872 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
873 pr_warn("PWM device already freed\n");
877 if (pwm->chip->ops->free)
878 pwm->chip->ops->free(pwm->chip, pwm);
882 module_put(pwm->chip->ops->owner);
884 mutex_unlock(&pwm_lock);
886 EXPORT_SYMBOL_GPL(pwm_put);
888 static void devm_pwm_release(struct device *dev, void *res)
890 pwm_put(*(struct pwm_device **)res);
894 * devm_pwm_get() - resource managed pwm_get()
895 * @dev: device for PWM consumer
896 * @con_id: consumer name
898 * This function performs like pwm_get() but the acquired PWM device will
899 * automatically be released on driver detach.
901 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
902 * error code on failure.
904 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
906 struct pwm_device **ptr, *pwm;
908 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
910 return ERR_PTR(-ENOMEM);
912 pwm = pwm_get(dev, con_id);
915 devres_add(dev, ptr);
922 EXPORT_SYMBOL_GPL(devm_pwm_get);
925 * devm_of_pwm_get() - resource managed of_pwm_get()
926 * @dev: device for PWM consumer
927 * @np: device node to get the PWM from
928 * @con_id: consumer name
930 * This function performs like of_pwm_get() but the acquired PWM device will
931 * automatically be released on driver detach.
933 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
934 * error code on failure.
936 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
939 struct pwm_device **ptr, *pwm;
941 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
943 return ERR_PTR(-ENOMEM);
945 pwm = of_pwm_get(np, con_id);
948 devres_add(dev, ptr);
955 EXPORT_SYMBOL_GPL(devm_of_pwm_get);
957 static int devm_pwm_match(struct device *dev, void *res, void *data)
959 struct pwm_device **p = res;
961 if (WARN_ON(!p || !*p))
968 * devm_pwm_put() - resource managed pwm_put()
969 * @dev: device for PWM consumer
972 * Release a PWM previously allocated using devm_pwm_get(). Calling this
973 * function is usually not needed because devm-allocated resources are
974 * automatically released on driver detach.
976 void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
978 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
980 EXPORT_SYMBOL_GPL(devm_pwm_put);
982 #ifdef CONFIG_DEBUG_FS
983 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
987 for (i = 0; i < chip->npwm; i++) {
988 struct pwm_device *pwm = &chip->pwms[i];
989 struct pwm_state state;
991 pwm_get_state(pwm, &state);
993 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
995 if (test_bit(PWMF_REQUESTED, &pwm->flags))
996 seq_puts(s, " requested");
999 seq_puts(s, " enabled");
1001 seq_printf(s, " period: %u ns", state.period);
1002 seq_printf(s, " duty: %u ns", state.duty_cycle);
1003 seq_printf(s, " polarity: %s",
1004 state.polarity ? "inverse" : "normal");
1010 static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1012 mutex_lock(&pwm_lock);
1015 return seq_list_start(&pwm_chips, *pos);
1018 static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1022 return seq_list_next(v, &pwm_chips, pos);
1025 static void pwm_seq_stop(struct seq_file *s, void *v)
1027 mutex_unlock(&pwm_lock);
1030 static int pwm_seq_show(struct seq_file *s, void *v)
1032 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1034 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1035 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1036 dev_name(chip->dev), chip->npwm,
1037 (chip->npwm != 1) ? "s" : "");
1039 pwm_dbg_show(chip, s);
1044 static const struct seq_operations pwm_seq_ops = {
1045 .start = pwm_seq_start,
1046 .next = pwm_seq_next,
1047 .stop = pwm_seq_stop,
1048 .show = pwm_seq_show,
1051 static int pwm_seq_open(struct inode *inode, struct file *file)
1053 return seq_open(file, &pwm_seq_ops);
1056 static const struct file_operations pwm_debugfs_ops = {
1057 .owner = THIS_MODULE,
1058 .open = pwm_seq_open,
1060 .llseek = seq_lseek,
1061 .release = seq_release,
1064 static int __init pwm_debugfs_init(void)
1066 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
1071 subsys_initcall(pwm_debugfs_init);
1072 #endif /* CONFIG_DEBUG_FS */