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/acpi.h>
23 #include <linux/module.h>
24 #include <linux/pwm.h>
25 #include <linux/radix-tree.h>
26 #include <linux/list.h>
27 #include <linux/mutex.h>
28 #include <linux/err.h>
29 #include <linux/slab.h>
30 #include <linux/device.h>
31 #include <linux/debugfs.h>
32 #include <linux/seq_file.h>
34 #include <dt-bindings/pwm/pwm.h>
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;
61 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
64 if (pwm >= 0 && start != pwm)
67 if (start + count > MAX_PWMS)
73 static void free_pwms(struct pwm_chip *chip)
77 for (i = 0; i < chip->npwm; i++) {
78 struct pwm_device *pwm = &chip->pwms[i];
80 radix_tree_delete(&pwm_tree, pwm->pwm);
83 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
89 static struct pwm_chip *pwmchip_find_by_name(const char *name)
91 struct pwm_chip *chip;
96 mutex_lock(&pwm_lock);
98 list_for_each_entry(chip, &pwm_chips, list) {
99 const char *chip_name = dev_name(chip->dev);
101 if (chip_name && strcmp(chip_name, name) == 0) {
102 mutex_unlock(&pwm_lock);
107 mutex_unlock(&pwm_lock);
112 static int pwm_device_request(struct pwm_device *pwm, const char *label)
116 if (test_bit(PWMF_REQUESTED, &pwm->flags))
119 if (!try_module_get(pwm->chip->ops->owner))
122 if (pwm->chip->ops->request) {
123 err = pwm->chip->ops->request(pwm->chip, pwm);
125 module_put(pwm->chip->ops->owner);
130 set_bit(PWMF_REQUESTED, &pwm->flags);
137 of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
139 struct pwm_device *pwm;
141 /* check, whether the driver supports a third cell for flags */
142 if (pc->of_pwm_n_cells < 3)
143 return ERR_PTR(-EINVAL);
145 /* flags in the third cell are optional */
146 if (args->args_count < 2)
147 return ERR_PTR(-EINVAL);
149 if (args->args[0] >= pc->npwm)
150 return ERR_PTR(-EINVAL);
152 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
156 pwm->args.period = args->args[1];
157 pwm->args.polarity = PWM_POLARITY_NORMAL;
159 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
160 pwm->args.polarity = PWM_POLARITY_INVERSED;
164 EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
166 static struct pwm_device *
167 of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
169 struct pwm_device *pwm;
171 /* sanity check driver support */
172 if (pc->of_pwm_n_cells < 2)
173 return ERR_PTR(-EINVAL);
175 /* all cells are required */
176 if (args->args_count != pc->of_pwm_n_cells)
177 return ERR_PTR(-EINVAL);
179 if (args->args[0] >= pc->npwm)
180 return ERR_PTR(-EINVAL);
182 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
186 pwm->args.period = args->args[1];
191 static void of_pwmchip_add(struct pwm_chip *chip)
193 if (!chip->dev || !chip->dev->of_node)
196 if (!chip->of_xlate) {
197 chip->of_xlate = of_pwm_simple_xlate;
198 chip->of_pwm_n_cells = 2;
201 of_node_get(chip->dev->of_node);
204 static void of_pwmchip_remove(struct pwm_chip *chip)
207 of_node_put(chip->dev->of_node);
211 * pwm_set_chip_data() - set private chip data for a PWM
213 * @data: pointer to chip-specific data
215 * Returns: 0 on success or a negative error code on failure.
217 int pwm_set_chip_data(struct pwm_device *pwm, void *data)
222 pwm->chip_data = data;
226 EXPORT_SYMBOL_GPL(pwm_set_chip_data);
229 * pwm_get_chip_data() - get private chip data for a PWM
232 * Returns: A pointer to the chip-private data for the PWM device.
234 void *pwm_get_chip_data(struct pwm_device *pwm)
236 return pwm ? pwm->chip_data : NULL;
238 EXPORT_SYMBOL_GPL(pwm_get_chip_data);
240 static bool pwm_ops_check(const struct pwm_ops *ops)
242 /* driver supports legacy, non-atomic operation */
243 if (ops->config && ops->enable && ops->disable)
246 /* driver supports atomic operation */
254 * pwmchip_add_with_polarity() - register a new PWM chip
255 * @chip: the PWM chip to add
256 * @polarity: initial polarity of PWM channels
258 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
259 * will be used. The initial polarity for all channels is specified by the
260 * @polarity parameter.
262 * Returns: 0 on success or a negative error code on failure.
264 int pwmchip_add_with_polarity(struct pwm_chip *chip,
265 enum pwm_polarity polarity)
267 struct pwm_device *pwm;
271 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
274 if (!pwm_ops_check(chip->ops))
277 mutex_lock(&pwm_lock);
279 ret = alloc_pwms(chip->base, chip->npwm);
283 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
291 for (i = 0; i < chip->npwm; i++) {
292 pwm = &chip->pwms[i];
295 pwm->pwm = chip->base + i;
297 pwm->state.polarity = polarity;
299 if (chip->ops->get_state)
300 chip->ops->get_state(chip, pwm, &pwm->state);
302 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
305 bitmap_set(allocated_pwms, chip->base, chip->npwm);
307 INIT_LIST_HEAD(&chip->list);
308 list_add(&chip->list, &pwm_chips);
312 if (IS_ENABLED(CONFIG_OF))
313 of_pwmchip_add(chip);
316 mutex_unlock(&pwm_lock);
319 pwmchip_sysfs_export(chip);
323 EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity);
326 * pwmchip_add() - register a new PWM chip
327 * @chip: the PWM chip to add
329 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
330 * will be used. The initial polarity for all channels is normal.
332 * Returns: 0 on success or a negative error code on failure.
334 int pwmchip_add(struct pwm_chip *chip)
336 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
338 EXPORT_SYMBOL_GPL(pwmchip_add);
341 * pwmchip_remove() - remove a PWM chip
342 * @chip: the PWM chip to remove
344 * Removes a PWM chip. This function may return busy if the PWM chip provides
345 * a PWM device that is still requested.
347 * Returns: 0 on success or a negative error code on failure.
349 int pwmchip_remove(struct pwm_chip *chip)
354 pwmchip_sysfs_unexport(chip);
356 mutex_lock(&pwm_lock);
358 for (i = 0; i < chip->npwm; i++) {
359 struct pwm_device *pwm = &chip->pwms[i];
361 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
367 list_del_init(&chip->list);
369 if (IS_ENABLED(CONFIG_OF))
370 of_pwmchip_remove(chip);
375 mutex_unlock(&pwm_lock);
378 EXPORT_SYMBOL_GPL(pwmchip_remove);
381 * pwm_request() - request a PWM device
382 * @pwm: global PWM device index
383 * @label: PWM device label
385 * This function is deprecated, use pwm_get() instead.
387 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
390 struct pwm_device *pwm_request(int pwm, const char *label)
392 struct pwm_device *dev;
395 if (pwm < 0 || pwm >= MAX_PWMS)
396 return ERR_PTR(-EINVAL);
398 mutex_lock(&pwm_lock);
400 dev = pwm_to_device(pwm);
402 dev = ERR_PTR(-EPROBE_DEFER);
406 err = pwm_device_request(dev, label);
411 mutex_unlock(&pwm_lock);
415 EXPORT_SYMBOL_GPL(pwm_request);
418 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
420 * @index: per-chip index of the PWM to request
421 * @label: a literal description string of this PWM
423 * Returns: A pointer to the PWM device at the given index of the given PWM
424 * chip. A negative error code is returned if the index is not valid for the
425 * specified PWM chip or if the PWM device cannot be requested.
427 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
431 struct pwm_device *pwm;
434 if (!chip || index >= chip->npwm)
435 return ERR_PTR(-EINVAL);
437 mutex_lock(&pwm_lock);
438 pwm = &chip->pwms[index];
440 err = pwm_device_request(pwm, label);
444 mutex_unlock(&pwm_lock);
447 EXPORT_SYMBOL_GPL(pwm_request_from_chip);
450 * pwm_free() - free a PWM device
453 * This function is deprecated, use pwm_put() instead.
455 void pwm_free(struct pwm_device *pwm)
459 EXPORT_SYMBOL_GPL(pwm_free);
462 * pwm_apply_state() - atomically apply a new state to a PWM device
464 * @state: new state to apply. This can be adjusted by the PWM driver
465 * if the requested config is not achievable, for example,
466 * ->duty_cycle and ->period might be approximated.
468 int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state)
472 if (!pwm || !state || !state->period ||
473 state->duty_cycle > state->period)
476 if (state->period == pwm->state.period &&
477 state->duty_cycle == pwm->state.duty_cycle &&
478 state->polarity == pwm->state.polarity &&
479 state->enabled == pwm->state.enabled)
482 if (pwm->chip->ops->apply) {
483 err = pwm->chip->ops->apply(pwm->chip, pwm, state);
490 * FIXME: restore the initial state in case of error.
492 if (state->polarity != pwm->state.polarity) {
493 if (!pwm->chip->ops->set_polarity)
497 * Changing the polarity of a running PWM is
498 * only allowed when the PWM driver implements
501 if (pwm->state.enabled) {
502 pwm->chip->ops->disable(pwm->chip, pwm);
503 pwm->state.enabled = false;
506 err = pwm->chip->ops->set_polarity(pwm->chip, pwm,
511 pwm->state.polarity = state->polarity;
514 if (state->period != pwm->state.period ||
515 state->duty_cycle != pwm->state.duty_cycle) {
516 err = pwm->chip->ops->config(pwm->chip, pwm,
522 pwm->state.duty_cycle = state->duty_cycle;
523 pwm->state.period = state->period;
526 if (state->enabled != pwm->state.enabled) {
527 if (state->enabled) {
528 err = pwm->chip->ops->enable(pwm->chip, pwm);
532 pwm->chip->ops->disable(pwm->chip, pwm);
535 pwm->state.enabled = state->enabled;
541 EXPORT_SYMBOL_GPL(pwm_apply_state);
544 * pwm_capture() - capture and report a PWM signal
546 * @result: structure to fill with capture result
547 * @timeout: time to wait, in milliseconds, before giving up on capture
549 * Returns: 0 on success or a negative error code on failure.
551 int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
552 unsigned long timeout)
556 if (!pwm || !pwm->chip->ops)
559 if (!pwm->chip->ops->capture)
562 mutex_lock(&pwm_lock);
563 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
564 mutex_unlock(&pwm_lock);
568 EXPORT_SYMBOL_GPL(pwm_capture);
571 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
574 * This function will adjust the PWM config to the PWM arguments provided
575 * by the DT or PWM lookup table. This is particularly useful to adapt
576 * the bootloader config to the Linux one.
578 int pwm_adjust_config(struct pwm_device *pwm)
580 struct pwm_state state;
581 struct pwm_args pargs;
583 pwm_get_args(pwm, &pargs);
584 pwm_get_state(pwm, &state);
587 * If the current period is zero it means that either the PWM driver
588 * does not support initial state retrieval or the PWM has not yet
591 * In either case, we setup the new period and polarity, and assign a
595 state.duty_cycle = 0;
596 state.period = pargs.period;
597 state.polarity = pargs.polarity;
599 return pwm_apply_state(pwm, &state);
603 * Adjust the PWM duty cycle/period based on the period value provided
606 if (pargs.period != state.period) {
607 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
609 do_div(dutycycle, state.period);
610 state.duty_cycle = dutycycle;
611 state.period = pargs.period;
615 * If the polarity changed, we should also change the duty cycle.
617 if (pargs.polarity != state.polarity) {
618 state.polarity = pargs.polarity;
619 state.duty_cycle = state.period - state.duty_cycle;
622 return pwm_apply_state(pwm, &state);
624 EXPORT_SYMBOL_GPL(pwm_adjust_config);
626 static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
628 struct pwm_chip *chip;
630 mutex_lock(&pwm_lock);
632 list_for_each_entry(chip, &pwm_chips, list)
633 if (chip->dev && chip->dev->of_node == np) {
634 mutex_unlock(&pwm_lock);
638 mutex_unlock(&pwm_lock);
640 return ERR_PTR(-EPROBE_DEFER);
643 static struct device_link *pwm_device_link_add(struct device *dev,
644 struct pwm_device *pwm)
646 struct device_link *dl;
650 * No device for the PWM consumer has been provided. It may
651 * impact the PM sequence ordering: the PWM supplier may get
652 * suspended before the consumer.
654 dev_warn(pwm->chip->dev,
655 "No consumer device specified to create a link to\n");
659 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
661 dev_err(dev, "failed to create device link to %s\n",
662 dev_name(pwm->chip->dev));
663 return ERR_PTR(-EINVAL);
670 * of_pwm_get() - request a PWM via the PWM framework
671 * @dev: device for PWM consumer
672 * @np: device node to get the PWM from
673 * @con_id: consumer name
675 * Returns the PWM device parsed from the phandle and index specified in the
676 * "pwms" property of a device tree node or a negative error-code on failure.
677 * Values parsed from the device tree are stored in the returned PWM device
680 * If con_id is NULL, the first PWM device listed in the "pwms" property will
681 * be requested. Otherwise the "pwm-names" property is used to do a reverse
682 * lookup of the PWM index. This also means that the "pwm-names" property
683 * becomes mandatory for devices that look up the PWM device via the con_id
686 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
687 * error code on failure.
689 struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
692 struct pwm_device *pwm = NULL;
693 struct of_phandle_args args;
694 struct device_link *dl;
700 index = of_property_match_string(np, "pwm-names", con_id);
702 return ERR_PTR(index);
705 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
708 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
712 pc = of_node_to_pwmchip(args.np);
714 if (PTR_ERR(pc) != -EPROBE_DEFER)
715 pr_err("%s(): PWM chip not found\n", __func__);
721 pwm = pc->of_xlate(pc, &args);
725 dl = pwm_device_link_add(dev, pwm);
727 /* of_xlate ended up calling pwm_request_from_chip() */
734 * If a consumer name was not given, try to look it up from the
735 * "pwm-names" property if it exists. Otherwise use the name of
736 * the user device node.
739 err = of_property_read_string_index(np, "pwm-names", index,
748 of_node_put(args.np);
752 EXPORT_SYMBOL_GPL(of_pwm_get);
754 #if IS_ENABLED(CONFIG_ACPI)
755 static struct pwm_chip *device_to_pwmchip(struct device *dev)
757 struct pwm_chip *chip;
759 mutex_lock(&pwm_lock);
761 list_for_each_entry(chip, &pwm_chips, list) {
762 struct acpi_device *adev = ACPI_COMPANION(chip->dev);
764 if ((chip->dev == dev) || (adev && &adev->dev == dev)) {
765 mutex_unlock(&pwm_lock);
770 mutex_unlock(&pwm_lock);
772 return ERR_PTR(-EPROBE_DEFER);
777 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
778 * @fwnode: firmware node to get the "pwm" property from
780 * Returns the PWM device parsed from the fwnode and index specified in the
781 * "pwms" property or a negative error-code on failure.
782 * Values parsed from the device tree are stored in the returned PWM device
785 * This is analogous to of_pwm_get() except con_id is not yet supported.
786 * ACPI entries must look like
787 * Package () {"pwms", Package ()
788 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
790 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
791 * error code on failure.
793 static struct pwm_device *acpi_pwm_get(struct fwnode_handle *fwnode)
795 struct pwm_device *pwm = ERR_PTR(-ENODEV);
796 #if IS_ENABLED(CONFIG_ACPI)
797 struct fwnode_reference_args args;
798 struct acpi_device *acpi;
799 struct pwm_chip *chip;
802 memset(&args, 0, sizeof(args));
804 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
808 acpi = to_acpi_device_node(args.fwnode);
810 return ERR_PTR(-EINVAL);
813 return ERR_PTR(-EPROTO);
815 chip = device_to_pwmchip(&acpi->dev);
817 return ERR_CAST(chip);
819 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
823 pwm->args.period = args.args[1];
824 pwm->args.polarity = PWM_POLARITY_NORMAL;
826 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
827 pwm->args.polarity = PWM_POLARITY_INVERSED;
834 * pwm_add_table() - register PWM device consumers
835 * @table: array of consumers to register
836 * @num: number of consumers in table
838 void pwm_add_table(struct pwm_lookup *table, size_t num)
840 mutex_lock(&pwm_lookup_lock);
843 list_add_tail(&table->list, &pwm_lookup_list);
847 mutex_unlock(&pwm_lookup_lock);
851 * pwm_remove_table() - unregister PWM device consumers
852 * @table: array of consumers to unregister
853 * @num: number of consumers in table
855 void pwm_remove_table(struct pwm_lookup *table, size_t num)
857 mutex_lock(&pwm_lookup_lock);
860 list_del(&table->list);
864 mutex_unlock(&pwm_lookup_lock);
868 * pwm_get() - look up and request a PWM device
869 * @dev: device for PWM consumer
870 * @con_id: consumer name
872 * Lookup is first attempted using DT. If the device was not instantiated from
873 * a device tree, a PWM chip and a relative index is looked up via a table
874 * supplied by board setup code (see pwm_add_table()).
876 * Once a PWM chip has been found the specified PWM device will be requested
877 * and is ready to be used.
879 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
880 * error code on failure.
882 struct pwm_device *pwm_get(struct device *dev, const char *con_id)
884 const char *dev_id = dev ? dev_name(dev) : NULL;
885 struct pwm_device *pwm;
886 struct pwm_chip *chip;
887 struct device_link *dl;
888 unsigned int best = 0;
889 struct pwm_lookup *p, *chosen = NULL;
893 /* look up via DT first */
894 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
895 return of_pwm_get(dev, dev->of_node, con_id);
897 /* then lookup via ACPI */
898 if (dev && is_acpi_node(dev->fwnode))
899 return acpi_pwm_get(dev->fwnode);
902 * We look up the provider in the static table typically provided by
903 * board setup code. We first try to lookup the consumer device by
904 * name. If the consumer device was passed in as NULL or if no match
905 * was found, we try to find the consumer by directly looking it up
908 * If a match is found, the provider PWM chip is looked up by name
909 * and a PWM device is requested using the PWM device per-chip index.
911 * The lookup algorithm was shamelessly taken from the clock
914 * We do slightly fuzzy matching here:
915 * An entry with a NULL ID is assumed to be a wildcard.
916 * If an entry has a device ID, it must match
917 * If an entry has a connection ID, it must match
918 * Then we take the most specific entry - with the following order
919 * of precedence: dev+con > dev only > con only.
921 mutex_lock(&pwm_lookup_lock);
923 list_for_each_entry(p, &pwm_lookup_list, list) {
927 if (!dev_id || strcmp(p->dev_id, dev_id))
934 if (!con_id || strcmp(p->con_id, con_id))
950 mutex_unlock(&pwm_lookup_lock);
953 return ERR_PTR(-ENODEV);
955 chip = pwmchip_find_by_name(chosen->provider);
958 * If the lookup entry specifies a module, load the module and retry
959 * the PWM chip lookup. This can be used to work around driver load
960 * ordering issues if driver's can't be made to properly support the
961 * deferred probe mechanism.
963 if (!chip && chosen->module) {
964 err = request_module(chosen->module);
966 chip = pwmchip_find_by_name(chosen->provider);
970 return ERR_PTR(-EPROBE_DEFER);
972 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
976 dl = pwm_device_link_add(dev, pwm);
982 pwm->args.period = chosen->period;
983 pwm->args.polarity = chosen->polarity;
987 EXPORT_SYMBOL_GPL(pwm_get);
990 * pwm_put() - release a PWM device
993 void pwm_put(struct pwm_device *pwm)
998 mutex_lock(&pwm_lock);
1000 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
1001 pr_warn("PWM device already freed\n");
1005 if (pwm->chip->ops->free)
1006 pwm->chip->ops->free(pwm->chip, pwm);
1008 pwm_set_chip_data(pwm, NULL);
1011 module_put(pwm->chip->ops->owner);
1013 mutex_unlock(&pwm_lock);
1015 EXPORT_SYMBOL_GPL(pwm_put);
1017 static void devm_pwm_release(struct device *dev, void *res)
1019 pwm_put(*(struct pwm_device **)res);
1023 * devm_pwm_get() - resource managed pwm_get()
1024 * @dev: device for PWM consumer
1025 * @con_id: consumer name
1027 * This function performs like pwm_get() but the acquired PWM device will
1028 * automatically be released on driver detach.
1030 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1031 * error code on failure.
1033 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
1035 struct pwm_device **ptr, *pwm;
1037 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1039 return ERR_PTR(-ENOMEM);
1041 pwm = pwm_get(dev, con_id);
1044 devres_add(dev, ptr);
1051 EXPORT_SYMBOL_GPL(devm_pwm_get);
1054 * devm_of_pwm_get() - resource managed of_pwm_get()
1055 * @dev: device for PWM consumer
1056 * @np: device node to get the PWM from
1057 * @con_id: consumer name
1059 * This function performs like of_pwm_get() but the acquired PWM device will
1060 * automatically be released on driver detach.
1062 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1063 * error code on failure.
1065 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
1068 struct pwm_device **ptr, *pwm;
1070 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1072 return ERR_PTR(-ENOMEM);
1074 pwm = of_pwm_get(dev, np, con_id);
1077 devres_add(dev, ptr);
1084 EXPORT_SYMBOL_GPL(devm_of_pwm_get);
1087 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
1088 * @dev: device for PWM consumer
1089 * @fwnode: firmware node to get the PWM from
1090 * @con_id: consumer name
1092 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
1093 * acpi_pwm_get() for a detailed description.
1095 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1096 * error code on failure.
1098 struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
1099 struct fwnode_handle *fwnode,
1102 struct pwm_device **ptr, *pwm = ERR_PTR(-ENODEV);
1104 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1106 return ERR_PTR(-ENOMEM);
1108 if (is_of_node(fwnode))
1109 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1110 else if (is_acpi_node(fwnode))
1111 pwm = acpi_pwm_get(fwnode);
1115 devres_add(dev, ptr);
1122 EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1124 static int devm_pwm_match(struct device *dev, void *res, void *data)
1126 struct pwm_device **p = res;
1128 if (WARN_ON(!p || !*p))
1135 * devm_pwm_put() - resource managed pwm_put()
1136 * @dev: device for PWM consumer
1139 * Release a PWM previously allocated using devm_pwm_get(). Calling this
1140 * function is usually not needed because devm-allocated resources are
1141 * automatically released on driver detach.
1143 void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
1145 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
1147 EXPORT_SYMBOL_GPL(devm_pwm_put);
1149 #ifdef CONFIG_DEBUG_FS
1150 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1154 for (i = 0; i < chip->npwm; i++) {
1155 struct pwm_device *pwm = &chip->pwms[i];
1156 struct pwm_state state;
1158 pwm_get_state(pwm, &state);
1160 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1162 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1163 seq_puts(s, " requested");
1166 seq_puts(s, " enabled");
1168 seq_printf(s, " period: %u ns", state.period);
1169 seq_printf(s, " duty: %u ns", state.duty_cycle);
1170 seq_printf(s, " polarity: %s",
1171 state.polarity ? "inverse" : "normal");
1177 static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1179 mutex_lock(&pwm_lock);
1182 return seq_list_start(&pwm_chips, *pos);
1185 static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1189 return seq_list_next(v, &pwm_chips, pos);
1192 static void pwm_seq_stop(struct seq_file *s, void *v)
1194 mutex_unlock(&pwm_lock);
1197 static int pwm_seq_show(struct seq_file *s, void *v)
1199 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1201 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1202 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1203 dev_name(chip->dev), chip->npwm,
1204 (chip->npwm != 1) ? "s" : "");
1206 pwm_dbg_show(chip, s);
1211 static const struct seq_operations pwm_seq_ops = {
1212 .start = pwm_seq_start,
1213 .next = pwm_seq_next,
1214 .stop = pwm_seq_stop,
1215 .show = pwm_seq_show,
1218 static int pwm_seq_open(struct inode *inode, struct file *file)
1220 return seq_open(file, &pwm_seq_ops);
1223 static const struct file_operations pwm_debugfs_ops = {
1224 .owner = THIS_MODULE,
1225 .open = pwm_seq_open,
1227 .llseek = seq_lseek,
1228 .release = seq_release,
1231 static int __init pwm_debugfs_init(void)
1233 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
1238 subsys_initcall(pwm_debugfs_init);
1239 #endif /* CONFIG_DEBUG_FS */