1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Generic pwmlib implementation
5 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
6 * Copyright (C) 2011-2012 Avionic Design GmbH
9 #include <linux/acpi.h>
10 #include <linux/module.h>
11 #include <linux/pwm.h>
12 #include <linux/radix-tree.h>
13 #include <linux/list.h>
14 #include <linux/mutex.h>
15 #include <linux/err.h>
16 #include <linux/slab.h>
17 #include <linux/device.h>
18 #include <linux/debugfs.h>
19 #include <linux/seq_file.h>
21 #include <dt-bindings/pwm/pwm.h>
25 static DEFINE_MUTEX(pwm_lookup_lock);
26 static LIST_HEAD(pwm_lookup_list);
27 static DEFINE_MUTEX(pwm_lock);
28 static LIST_HEAD(pwm_chips);
29 static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
30 static RADIX_TREE(pwm_tree, GFP_KERNEL);
32 static struct pwm_device *pwm_to_device(unsigned int pwm)
34 return radix_tree_lookup(&pwm_tree, pwm);
37 static int alloc_pwms(int pwm, unsigned int count)
39 unsigned int from = 0;
48 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
51 if (pwm >= 0 && start != pwm)
54 if (start + count > MAX_PWMS)
60 static void free_pwms(struct pwm_chip *chip)
64 for (i = 0; i < chip->npwm; i++) {
65 struct pwm_device *pwm = &chip->pwms[i];
67 radix_tree_delete(&pwm_tree, pwm->pwm);
70 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
76 static struct pwm_chip *pwmchip_find_by_name(const char *name)
78 struct pwm_chip *chip;
83 mutex_lock(&pwm_lock);
85 list_for_each_entry(chip, &pwm_chips, list) {
86 const char *chip_name = dev_name(chip->dev);
88 if (chip_name && strcmp(chip_name, name) == 0) {
89 mutex_unlock(&pwm_lock);
94 mutex_unlock(&pwm_lock);
99 static int pwm_device_request(struct pwm_device *pwm, const char *label)
103 if (test_bit(PWMF_REQUESTED, &pwm->flags))
106 if (!try_module_get(pwm->chip->ops->owner))
109 if (pwm->chip->ops->request) {
110 err = pwm->chip->ops->request(pwm->chip, pwm);
112 module_put(pwm->chip->ops->owner);
117 set_bit(PWMF_REQUESTED, &pwm->flags);
124 of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
126 struct pwm_device *pwm;
128 /* check, whether the driver supports a third cell for flags */
129 if (pc->of_pwm_n_cells < 3)
130 return ERR_PTR(-EINVAL);
132 /* flags in the third cell are optional */
133 if (args->args_count < 2)
134 return ERR_PTR(-EINVAL);
136 if (args->args[0] >= pc->npwm)
137 return ERR_PTR(-EINVAL);
139 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
143 pwm->args.period = args->args[1];
144 pwm->args.polarity = PWM_POLARITY_NORMAL;
146 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
147 pwm->args.polarity = PWM_POLARITY_INVERSED;
151 EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
153 static struct pwm_device *
154 of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
156 struct pwm_device *pwm;
158 /* sanity check driver support */
159 if (pc->of_pwm_n_cells < 2)
160 return ERR_PTR(-EINVAL);
162 /* all cells are required */
163 if (args->args_count != pc->of_pwm_n_cells)
164 return ERR_PTR(-EINVAL);
166 if (args->args[0] >= pc->npwm)
167 return ERR_PTR(-EINVAL);
169 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
173 pwm->args.period = args->args[1];
178 static void of_pwmchip_add(struct pwm_chip *chip)
180 if (!chip->dev || !chip->dev->of_node)
183 if (!chip->of_xlate) {
184 chip->of_xlate = of_pwm_simple_xlate;
185 chip->of_pwm_n_cells = 2;
188 of_node_get(chip->dev->of_node);
191 static void of_pwmchip_remove(struct pwm_chip *chip)
194 of_node_put(chip->dev->of_node);
198 * pwm_set_chip_data() - set private chip data for a PWM
200 * @data: pointer to chip-specific data
202 * Returns: 0 on success or a negative error code on failure.
204 int pwm_set_chip_data(struct pwm_device *pwm, void *data)
209 pwm->chip_data = data;
213 EXPORT_SYMBOL_GPL(pwm_set_chip_data);
216 * pwm_get_chip_data() - get private chip data for a PWM
219 * Returns: A pointer to the chip-private data for the PWM device.
221 void *pwm_get_chip_data(struct pwm_device *pwm)
223 return pwm ? pwm->chip_data : NULL;
225 EXPORT_SYMBOL_GPL(pwm_get_chip_data);
227 static bool pwm_ops_check(const struct pwm_ops *ops)
229 /* driver supports legacy, non-atomic operation */
230 if (ops->config && ops->enable && ops->disable)
233 /* driver supports atomic operation */
241 * pwmchip_add_with_polarity() - register a new PWM chip
242 * @chip: the PWM chip to add
243 * @polarity: initial polarity of PWM channels
245 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
246 * will be used. The initial polarity for all channels is specified by the
247 * @polarity parameter.
249 * Returns: 0 on success or a negative error code on failure.
251 int pwmchip_add_with_polarity(struct pwm_chip *chip,
252 enum pwm_polarity polarity)
254 struct pwm_device *pwm;
258 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
261 if (!pwm_ops_check(chip->ops))
264 mutex_lock(&pwm_lock);
266 ret = alloc_pwms(chip->base, chip->npwm);
270 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
278 for (i = 0; i < chip->npwm; i++) {
279 pwm = &chip->pwms[i];
282 pwm->pwm = chip->base + i;
284 pwm->state.polarity = polarity;
286 if (chip->ops->get_state)
287 chip->ops->get_state(chip, pwm, &pwm->state);
289 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
292 bitmap_set(allocated_pwms, chip->base, chip->npwm);
294 INIT_LIST_HEAD(&chip->list);
295 list_add(&chip->list, &pwm_chips);
299 if (IS_ENABLED(CONFIG_OF))
300 of_pwmchip_add(chip);
303 mutex_unlock(&pwm_lock);
306 pwmchip_sysfs_export(chip);
310 EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity);
313 * pwmchip_add() - register a new PWM chip
314 * @chip: the PWM chip to add
316 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
317 * will be used. The initial polarity for all channels is normal.
319 * Returns: 0 on success or a negative error code on failure.
321 int pwmchip_add(struct pwm_chip *chip)
323 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
325 EXPORT_SYMBOL_GPL(pwmchip_add);
328 * pwmchip_remove() - remove a PWM chip
329 * @chip: the PWM chip to remove
331 * Removes a PWM chip. This function may return busy if the PWM chip provides
332 * a PWM device that is still requested.
334 * Returns: 0 on success or a negative error code on failure.
336 int pwmchip_remove(struct pwm_chip *chip)
341 pwmchip_sysfs_unexport(chip);
343 mutex_lock(&pwm_lock);
345 for (i = 0; i < chip->npwm; i++) {
346 struct pwm_device *pwm = &chip->pwms[i];
348 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
354 list_del_init(&chip->list);
356 if (IS_ENABLED(CONFIG_OF))
357 of_pwmchip_remove(chip);
362 mutex_unlock(&pwm_lock);
365 EXPORT_SYMBOL_GPL(pwmchip_remove);
368 * pwm_request() - request a PWM device
369 * @pwm: global PWM device index
370 * @label: PWM device label
372 * This function is deprecated, use pwm_get() instead.
374 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
377 struct pwm_device *pwm_request(int pwm, const char *label)
379 struct pwm_device *dev;
382 if (pwm < 0 || pwm >= MAX_PWMS)
383 return ERR_PTR(-EINVAL);
385 mutex_lock(&pwm_lock);
387 dev = pwm_to_device(pwm);
389 dev = ERR_PTR(-EPROBE_DEFER);
393 err = pwm_device_request(dev, label);
398 mutex_unlock(&pwm_lock);
402 EXPORT_SYMBOL_GPL(pwm_request);
405 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
407 * @index: per-chip index of the PWM to request
408 * @label: a literal description string of this PWM
410 * Returns: A pointer to the PWM device at the given index of the given PWM
411 * chip. A negative error code is returned if the index is not valid for the
412 * specified PWM chip or if the PWM device cannot be requested.
414 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
418 struct pwm_device *pwm;
421 if (!chip || index >= chip->npwm)
422 return ERR_PTR(-EINVAL);
424 mutex_lock(&pwm_lock);
425 pwm = &chip->pwms[index];
427 err = pwm_device_request(pwm, label);
431 mutex_unlock(&pwm_lock);
434 EXPORT_SYMBOL_GPL(pwm_request_from_chip);
437 * pwm_free() - free a PWM device
440 * This function is deprecated, use pwm_put() instead.
442 void pwm_free(struct pwm_device *pwm)
446 EXPORT_SYMBOL_GPL(pwm_free);
449 * pwm_apply_state() - atomically apply a new state to a PWM device
451 * @state: new state to apply. This can be adjusted by the PWM driver
452 * if the requested config is not achievable, for example,
453 * ->duty_cycle and ->period might be approximated.
455 int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state)
457 struct pwm_chip *chip;
460 if (!pwm || !state || !state->period ||
461 state->duty_cycle > state->period)
466 if (state->period == pwm->state.period &&
467 state->duty_cycle == pwm->state.duty_cycle &&
468 state->polarity == pwm->state.polarity &&
469 state->enabled == pwm->state.enabled)
472 if (chip->ops->apply) {
473 err = chip->ops->apply(chip, pwm, state);
478 * .apply might have to round some values in *state, if possible
479 * read the actually implemented value back.
481 if (chip->ops->get_state)
482 chip->ops->get_state(chip, pwm, &pwm->state);
487 * FIXME: restore the initial state in case of error.
489 if (state->polarity != pwm->state.polarity) {
490 if (!chip->ops->set_polarity)
494 * Changing the polarity of a running PWM is
495 * only allowed when the PWM driver implements
498 if (pwm->state.enabled) {
499 chip->ops->disable(chip, pwm);
500 pwm->state.enabled = false;
503 err = chip->ops->set_polarity(chip, pwm,
508 pwm->state.polarity = state->polarity;
511 if (state->period != pwm->state.period ||
512 state->duty_cycle != pwm->state.duty_cycle) {
513 err = chip->ops->config(pwm->chip, pwm,
519 pwm->state.duty_cycle = state->duty_cycle;
520 pwm->state.period = state->period;
523 if (state->enabled != pwm->state.enabled) {
524 if (state->enabled) {
525 err = chip->ops->enable(chip, pwm);
529 chip->ops->disable(chip, pwm);
532 pwm->state.enabled = state->enabled;
538 EXPORT_SYMBOL_GPL(pwm_apply_state);
541 * pwm_capture() - capture and report a PWM signal
543 * @result: structure to fill with capture result
544 * @timeout: time to wait, in milliseconds, before giving up on capture
546 * Returns: 0 on success or a negative error code on failure.
548 int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
549 unsigned long timeout)
553 if (!pwm || !pwm->chip->ops)
556 if (!pwm->chip->ops->capture)
559 mutex_lock(&pwm_lock);
560 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
561 mutex_unlock(&pwm_lock);
565 EXPORT_SYMBOL_GPL(pwm_capture);
568 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
571 * This function will adjust the PWM config to the PWM arguments provided
572 * by the DT or PWM lookup table. This is particularly useful to adapt
573 * the bootloader config to the Linux one.
575 int pwm_adjust_config(struct pwm_device *pwm)
577 struct pwm_state state;
578 struct pwm_args pargs;
580 pwm_get_args(pwm, &pargs);
581 pwm_get_state(pwm, &state);
584 * If the current period is zero it means that either the PWM driver
585 * does not support initial state retrieval or the PWM has not yet
588 * In either case, we setup the new period and polarity, and assign a
592 state.duty_cycle = 0;
593 state.period = pargs.period;
594 state.polarity = pargs.polarity;
596 return pwm_apply_state(pwm, &state);
600 * Adjust the PWM duty cycle/period based on the period value provided
603 if (pargs.period != state.period) {
604 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
606 do_div(dutycycle, state.period);
607 state.duty_cycle = dutycycle;
608 state.period = pargs.period;
612 * If the polarity changed, we should also change the duty cycle.
614 if (pargs.polarity != state.polarity) {
615 state.polarity = pargs.polarity;
616 state.duty_cycle = state.period - state.duty_cycle;
619 return pwm_apply_state(pwm, &state);
621 EXPORT_SYMBOL_GPL(pwm_adjust_config);
623 static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
625 struct pwm_chip *chip;
627 mutex_lock(&pwm_lock);
629 list_for_each_entry(chip, &pwm_chips, list)
630 if (chip->dev && chip->dev->of_node == np) {
631 mutex_unlock(&pwm_lock);
635 mutex_unlock(&pwm_lock);
637 return ERR_PTR(-EPROBE_DEFER);
640 static struct device_link *pwm_device_link_add(struct device *dev,
641 struct pwm_device *pwm)
643 struct device_link *dl;
647 * No device for the PWM consumer has been provided. It may
648 * impact the PM sequence ordering: the PWM supplier may get
649 * suspended before the consumer.
651 dev_warn(pwm->chip->dev,
652 "No consumer device specified to create a link to\n");
656 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
658 dev_err(dev, "failed to create device link to %s\n",
659 dev_name(pwm->chip->dev));
660 return ERR_PTR(-EINVAL);
667 * of_pwm_get() - request a PWM via the PWM framework
668 * @dev: device for PWM consumer
669 * @np: device node to get the PWM from
670 * @con_id: consumer name
672 * Returns the PWM device parsed from the phandle and index specified in the
673 * "pwms" property of a device tree node or a negative error-code on failure.
674 * Values parsed from the device tree are stored in the returned PWM device
677 * If con_id is NULL, the first PWM device listed in the "pwms" property will
678 * be requested. Otherwise the "pwm-names" property is used to do a reverse
679 * lookup of the PWM index. This also means that the "pwm-names" property
680 * becomes mandatory for devices that look up the PWM device via the con_id
683 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
684 * error code on failure.
686 struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
689 struct pwm_device *pwm = NULL;
690 struct of_phandle_args args;
691 struct device_link *dl;
697 index = of_property_match_string(np, "pwm-names", con_id);
699 return ERR_PTR(index);
702 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
705 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
709 pc = of_node_to_pwmchip(args.np);
711 if (PTR_ERR(pc) != -EPROBE_DEFER)
712 pr_err("%s(): PWM chip not found\n", __func__);
718 pwm = pc->of_xlate(pc, &args);
722 dl = pwm_device_link_add(dev, pwm);
724 /* of_xlate ended up calling pwm_request_from_chip() */
731 * If a consumer name was not given, try to look it up from the
732 * "pwm-names" property if it exists. Otherwise use the name of
733 * the user device node.
736 err = of_property_read_string_index(np, "pwm-names", index,
745 of_node_put(args.np);
749 EXPORT_SYMBOL_GPL(of_pwm_get);
751 #if IS_ENABLED(CONFIG_ACPI)
752 static struct pwm_chip *device_to_pwmchip(struct device *dev)
754 struct pwm_chip *chip;
756 mutex_lock(&pwm_lock);
758 list_for_each_entry(chip, &pwm_chips, list) {
759 struct acpi_device *adev = ACPI_COMPANION(chip->dev);
761 if ((chip->dev == dev) || (adev && &adev->dev == dev)) {
762 mutex_unlock(&pwm_lock);
767 mutex_unlock(&pwm_lock);
769 return ERR_PTR(-EPROBE_DEFER);
774 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
775 * @fwnode: firmware node to get the "pwm" property from
777 * Returns the PWM device parsed from the fwnode and index specified in the
778 * "pwms" property or a negative error-code on failure.
779 * Values parsed from the device tree are stored in the returned PWM device
782 * This is analogous to of_pwm_get() except con_id is not yet supported.
783 * ACPI entries must look like
784 * Package () {"pwms", Package ()
785 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
787 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
788 * error code on failure.
790 static struct pwm_device *acpi_pwm_get(struct fwnode_handle *fwnode)
792 struct pwm_device *pwm = ERR_PTR(-ENODEV);
793 #if IS_ENABLED(CONFIG_ACPI)
794 struct fwnode_reference_args args;
795 struct acpi_device *acpi;
796 struct pwm_chip *chip;
799 memset(&args, 0, sizeof(args));
801 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
805 acpi = to_acpi_device_node(args.fwnode);
807 return ERR_PTR(-EINVAL);
810 return ERR_PTR(-EPROTO);
812 chip = device_to_pwmchip(&acpi->dev);
814 return ERR_CAST(chip);
816 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
820 pwm->args.period = args.args[1];
821 pwm->args.polarity = PWM_POLARITY_NORMAL;
823 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
824 pwm->args.polarity = PWM_POLARITY_INVERSED;
831 * pwm_add_table() - register PWM device consumers
832 * @table: array of consumers to register
833 * @num: number of consumers in table
835 void pwm_add_table(struct pwm_lookup *table, size_t num)
837 mutex_lock(&pwm_lookup_lock);
840 list_add_tail(&table->list, &pwm_lookup_list);
844 mutex_unlock(&pwm_lookup_lock);
848 * pwm_remove_table() - unregister PWM device consumers
849 * @table: array of consumers to unregister
850 * @num: number of consumers in table
852 void pwm_remove_table(struct pwm_lookup *table, size_t num)
854 mutex_lock(&pwm_lookup_lock);
857 list_del(&table->list);
861 mutex_unlock(&pwm_lookup_lock);
865 * pwm_get() - look up and request a PWM device
866 * @dev: device for PWM consumer
867 * @con_id: consumer name
869 * Lookup is first attempted using DT. If the device was not instantiated from
870 * a device tree, a PWM chip and a relative index is looked up via a table
871 * supplied by board setup code (see pwm_add_table()).
873 * Once a PWM chip has been found the specified PWM device will be requested
874 * and is ready to be used.
876 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
877 * error code on failure.
879 struct pwm_device *pwm_get(struct device *dev, const char *con_id)
881 const char *dev_id = dev ? dev_name(dev) : NULL;
882 struct pwm_device *pwm;
883 struct pwm_chip *chip;
884 struct device_link *dl;
885 unsigned int best = 0;
886 struct pwm_lookup *p, *chosen = NULL;
890 /* look up via DT first */
891 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
892 return of_pwm_get(dev, dev->of_node, con_id);
894 /* then lookup via ACPI */
895 if (dev && is_acpi_node(dev->fwnode)) {
896 pwm = acpi_pwm_get(dev->fwnode);
897 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
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 */