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);
480 * FIXME: restore the initial state in case of error.
482 if (state->polarity != pwm->state.polarity) {
483 if (!chip->ops->set_polarity)
487 * Changing the polarity of a running PWM is
488 * only allowed when the PWM driver implements
491 if (pwm->state.enabled) {
492 chip->ops->disable(chip, pwm);
493 pwm->state.enabled = false;
496 err = chip->ops->set_polarity(chip, pwm,
501 pwm->state.polarity = state->polarity;
504 if (state->period != pwm->state.period ||
505 state->duty_cycle != pwm->state.duty_cycle) {
506 err = chip->ops->config(pwm->chip, pwm,
512 pwm->state.duty_cycle = state->duty_cycle;
513 pwm->state.period = state->period;
516 if (state->enabled != pwm->state.enabled) {
517 if (state->enabled) {
518 err = chip->ops->enable(chip, pwm);
522 chip->ops->disable(chip, pwm);
525 pwm->state.enabled = state->enabled;
531 EXPORT_SYMBOL_GPL(pwm_apply_state);
534 * pwm_capture() - capture and report a PWM signal
536 * @result: structure to fill with capture result
537 * @timeout: time to wait, in milliseconds, before giving up on capture
539 * Returns: 0 on success or a negative error code on failure.
541 int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
542 unsigned long timeout)
546 if (!pwm || !pwm->chip->ops)
549 if (!pwm->chip->ops->capture)
552 mutex_lock(&pwm_lock);
553 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
554 mutex_unlock(&pwm_lock);
558 EXPORT_SYMBOL_GPL(pwm_capture);
561 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
564 * This function will adjust the PWM config to the PWM arguments provided
565 * by the DT or PWM lookup table. This is particularly useful to adapt
566 * the bootloader config to the Linux one.
568 int pwm_adjust_config(struct pwm_device *pwm)
570 struct pwm_state state;
571 struct pwm_args pargs;
573 pwm_get_args(pwm, &pargs);
574 pwm_get_state(pwm, &state);
577 * If the current period is zero it means that either the PWM driver
578 * does not support initial state retrieval or the PWM has not yet
581 * In either case, we setup the new period and polarity, and assign a
585 state.duty_cycle = 0;
586 state.period = pargs.period;
587 state.polarity = pargs.polarity;
589 return pwm_apply_state(pwm, &state);
593 * Adjust the PWM duty cycle/period based on the period value provided
596 if (pargs.period != state.period) {
597 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
599 do_div(dutycycle, state.period);
600 state.duty_cycle = dutycycle;
601 state.period = pargs.period;
605 * If the polarity changed, we should also change the duty cycle.
607 if (pargs.polarity != state.polarity) {
608 state.polarity = pargs.polarity;
609 state.duty_cycle = state.period - state.duty_cycle;
612 return pwm_apply_state(pwm, &state);
614 EXPORT_SYMBOL_GPL(pwm_adjust_config);
616 static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
618 struct pwm_chip *chip;
620 mutex_lock(&pwm_lock);
622 list_for_each_entry(chip, &pwm_chips, list)
623 if (chip->dev && chip->dev->of_node == np) {
624 mutex_unlock(&pwm_lock);
628 mutex_unlock(&pwm_lock);
630 return ERR_PTR(-EPROBE_DEFER);
633 static struct device_link *pwm_device_link_add(struct device *dev,
634 struct pwm_device *pwm)
636 struct device_link *dl;
640 * No device for the PWM consumer has been provided. It may
641 * impact the PM sequence ordering: the PWM supplier may get
642 * suspended before the consumer.
644 dev_warn(pwm->chip->dev,
645 "No consumer device specified to create a link to\n");
649 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
651 dev_err(dev, "failed to create device link to %s\n",
652 dev_name(pwm->chip->dev));
653 return ERR_PTR(-EINVAL);
660 * of_pwm_get() - request a PWM via the PWM framework
661 * @dev: device for PWM consumer
662 * @np: device node to get the PWM from
663 * @con_id: consumer name
665 * Returns the PWM device parsed from the phandle and index specified in the
666 * "pwms" property of a device tree node or a negative error-code on failure.
667 * Values parsed from the device tree are stored in the returned PWM device
670 * If con_id is NULL, the first PWM device listed in the "pwms" property will
671 * be requested. Otherwise the "pwm-names" property is used to do a reverse
672 * lookup of the PWM index. This also means that the "pwm-names" property
673 * becomes mandatory for devices that look up the PWM device via the con_id
676 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
677 * error code on failure.
679 struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
682 struct pwm_device *pwm = NULL;
683 struct of_phandle_args args;
684 struct device_link *dl;
690 index = of_property_match_string(np, "pwm-names", con_id);
692 return ERR_PTR(index);
695 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
698 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
702 pc = of_node_to_pwmchip(args.np);
704 if (PTR_ERR(pc) != -EPROBE_DEFER)
705 pr_err("%s(): PWM chip not found\n", __func__);
711 pwm = pc->of_xlate(pc, &args);
715 dl = pwm_device_link_add(dev, pwm);
717 /* of_xlate ended up calling pwm_request_from_chip() */
724 * If a consumer name was not given, try to look it up from the
725 * "pwm-names" property if it exists. Otherwise use the name of
726 * the user device node.
729 err = of_property_read_string_index(np, "pwm-names", index,
738 of_node_put(args.np);
742 EXPORT_SYMBOL_GPL(of_pwm_get);
744 #if IS_ENABLED(CONFIG_ACPI)
745 static struct pwm_chip *device_to_pwmchip(struct device *dev)
747 struct pwm_chip *chip;
749 mutex_lock(&pwm_lock);
751 list_for_each_entry(chip, &pwm_chips, list) {
752 struct acpi_device *adev = ACPI_COMPANION(chip->dev);
754 if ((chip->dev == dev) || (adev && &adev->dev == dev)) {
755 mutex_unlock(&pwm_lock);
760 mutex_unlock(&pwm_lock);
762 return ERR_PTR(-EPROBE_DEFER);
767 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
768 * @fwnode: firmware node to get the "pwm" property from
770 * Returns the PWM device parsed from the fwnode and index specified in the
771 * "pwms" property or a negative error-code on failure.
772 * Values parsed from the device tree are stored in the returned PWM device
775 * This is analogous to of_pwm_get() except con_id is not yet supported.
776 * ACPI entries must look like
777 * Package () {"pwms", Package ()
778 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
780 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
781 * error code on failure.
783 static struct pwm_device *acpi_pwm_get(struct fwnode_handle *fwnode)
785 struct pwm_device *pwm = ERR_PTR(-ENODEV);
786 #if IS_ENABLED(CONFIG_ACPI)
787 struct fwnode_reference_args args;
788 struct acpi_device *acpi;
789 struct pwm_chip *chip;
792 memset(&args, 0, sizeof(args));
794 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
798 acpi = to_acpi_device_node(args.fwnode);
800 return ERR_PTR(-EINVAL);
803 return ERR_PTR(-EPROTO);
805 chip = device_to_pwmchip(&acpi->dev);
807 return ERR_CAST(chip);
809 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
813 pwm->args.period = args.args[1];
814 pwm->args.polarity = PWM_POLARITY_NORMAL;
816 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
817 pwm->args.polarity = PWM_POLARITY_INVERSED;
824 * pwm_add_table() - register PWM device consumers
825 * @table: array of consumers to register
826 * @num: number of consumers in table
828 void pwm_add_table(struct pwm_lookup *table, size_t num)
830 mutex_lock(&pwm_lookup_lock);
833 list_add_tail(&table->list, &pwm_lookup_list);
837 mutex_unlock(&pwm_lookup_lock);
841 * pwm_remove_table() - unregister PWM device consumers
842 * @table: array of consumers to unregister
843 * @num: number of consumers in table
845 void pwm_remove_table(struct pwm_lookup *table, size_t num)
847 mutex_lock(&pwm_lookup_lock);
850 list_del(&table->list);
854 mutex_unlock(&pwm_lookup_lock);
858 * pwm_get() - look up and request a PWM device
859 * @dev: device for PWM consumer
860 * @con_id: consumer name
862 * Lookup is first attempted using DT. If the device was not instantiated from
863 * a device tree, a PWM chip and a relative index is looked up via a table
864 * supplied by board setup code (see pwm_add_table()).
866 * Once a PWM chip has been found the specified PWM device will be requested
867 * and is ready to be used.
869 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
870 * error code on failure.
872 struct pwm_device *pwm_get(struct device *dev, const char *con_id)
874 const char *dev_id = dev ? dev_name(dev) : NULL;
875 struct pwm_device *pwm;
876 struct pwm_chip *chip;
877 struct device_link *dl;
878 unsigned int best = 0;
879 struct pwm_lookup *p, *chosen = NULL;
883 /* look up via DT first */
884 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
885 return of_pwm_get(dev, dev->of_node, con_id);
887 /* then lookup via ACPI */
888 if (dev && is_acpi_node(dev->fwnode)) {
889 pwm = acpi_pwm_get(dev->fwnode);
890 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
895 * We look up the provider in the static table typically provided by
896 * board setup code. We first try to lookup the consumer device by
897 * name. If the consumer device was passed in as NULL or if no match
898 * was found, we try to find the consumer by directly looking it up
901 * If a match is found, the provider PWM chip is looked up by name
902 * and a PWM device is requested using the PWM device per-chip index.
904 * The lookup algorithm was shamelessly taken from the clock
907 * We do slightly fuzzy matching here:
908 * An entry with a NULL ID is assumed to be a wildcard.
909 * If an entry has a device ID, it must match
910 * If an entry has a connection ID, it must match
911 * Then we take the most specific entry - with the following order
912 * of precedence: dev+con > dev only > con only.
914 mutex_lock(&pwm_lookup_lock);
916 list_for_each_entry(p, &pwm_lookup_list, list) {
920 if (!dev_id || strcmp(p->dev_id, dev_id))
927 if (!con_id || strcmp(p->con_id, con_id))
943 mutex_unlock(&pwm_lookup_lock);
946 return ERR_PTR(-ENODEV);
948 chip = pwmchip_find_by_name(chosen->provider);
951 * If the lookup entry specifies a module, load the module and retry
952 * the PWM chip lookup. This can be used to work around driver load
953 * ordering issues if driver's can't be made to properly support the
954 * deferred probe mechanism.
956 if (!chip && chosen->module) {
957 err = request_module(chosen->module);
959 chip = pwmchip_find_by_name(chosen->provider);
963 return ERR_PTR(-EPROBE_DEFER);
965 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
969 dl = pwm_device_link_add(dev, pwm);
975 pwm->args.period = chosen->period;
976 pwm->args.polarity = chosen->polarity;
980 EXPORT_SYMBOL_GPL(pwm_get);
983 * pwm_put() - release a PWM device
986 void pwm_put(struct pwm_device *pwm)
991 mutex_lock(&pwm_lock);
993 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
994 pr_warn("PWM device already freed\n");
998 if (pwm->chip->ops->free)
999 pwm->chip->ops->free(pwm->chip, pwm);
1001 pwm_set_chip_data(pwm, NULL);
1004 module_put(pwm->chip->ops->owner);
1006 mutex_unlock(&pwm_lock);
1008 EXPORT_SYMBOL_GPL(pwm_put);
1010 static void devm_pwm_release(struct device *dev, void *res)
1012 pwm_put(*(struct pwm_device **)res);
1016 * devm_pwm_get() - resource managed pwm_get()
1017 * @dev: device for PWM consumer
1018 * @con_id: consumer name
1020 * This function performs like pwm_get() but the acquired PWM device will
1021 * automatically be released on driver detach.
1023 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1024 * error code on failure.
1026 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
1028 struct pwm_device **ptr, *pwm;
1030 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1032 return ERR_PTR(-ENOMEM);
1034 pwm = pwm_get(dev, con_id);
1037 devres_add(dev, ptr);
1044 EXPORT_SYMBOL_GPL(devm_pwm_get);
1047 * devm_of_pwm_get() - resource managed of_pwm_get()
1048 * @dev: device for PWM consumer
1049 * @np: device node to get the PWM from
1050 * @con_id: consumer name
1052 * This function performs like of_pwm_get() but the acquired PWM device will
1053 * automatically be released on driver detach.
1055 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1056 * error code on failure.
1058 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
1061 struct pwm_device **ptr, *pwm;
1063 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1065 return ERR_PTR(-ENOMEM);
1067 pwm = of_pwm_get(dev, np, con_id);
1070 devres_add(dev, ptr);
1077 EXPORT_SYMBOL_GPL(devm_of_pwm_get);
1080 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
1081 * @dev: device for PWM consumer
1082 * @fwnode: firmware node to get the PWM from
1083 * @con_id: consumer name
1085 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
1086 * acpi_pwm_get() for a detailed description.
1088 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1089 * error code on failure.
1091 struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
1092 struct fwnode_handle *fwnode,
1095 struct pwm_device **ptr, *pwm = ERR_PTR(-ENODEV);
1097 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1099 return ERR_PTR(-ENOMEM);
1101 if (is_of_node(fwnode))
1102 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1103 else if (is_acpi_node(fwnode))
1104 pwm = acpi_pwm_get(fwnode);
1108 devres_add(dev, ptr);
1115 EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1117 static int devm_pwm_match(struct device *dev, void *res, void *data)
1119 struct pwm_device **p = res;
1121 if (WARN_ON(!p || !*p))
1128 * devm_pwm_put() - resource managed pwm_put()
1129 * @dev: device for PWM consumer
1132 * Release a PWM previously allocated using devm_pwm_get(). Calling this
1133 * function is usually not needed because devm-allocated resources are
1134 * automatically released on driver detach.
1136 void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
1138 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
1140 EXPORT_SYMBOL_GPL(devm_pwm_put);
1142 #ifdef CONFIG_DEBUG_FS
1143 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1147 for (i = 0; i < chip->npwm; i++) {
1148 struct pwm_device *pwm = &chip->pwms[i];
1149 struct pwm_state state;
1151 pwm_get_state(pwm, &state);
1153 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1155 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1156 seq_puts(s, " requested");
1159 seq_puts(s, " enabled");
1161 seq_printf(s, " period: %u ns", state.period);
1162 seq_printf(s, " duty: %u ns", state.duty_cycle);
1163 seq_printf(s, " polarity: %s",
1164 state.polarity ? "inverse" : "normal");
1170 static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1172 mutex_lock(&pwm_lock);
1175 return seq_list_start(&pwm_chips, *pos);
1178 static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1182 return seq_list_next(v, &pwm_chips, pos);
1185 static void pwm_seq_stop(struct seq_file *s, void *v)
1187 mutex_unlock(&pwm_lock);
1190 static int pwm_seq_show(struct seq_file *s, void *v)
1192 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1194 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1195 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1196 dev_name(chip->dev), chip->npwm,
1197 (chip->npwm != 1) ? "s" : "");
1199 pwm_dbg_show(chip, s);
1204 static const struct seq_operations pwm_seq_ops = {
1205 .start = pwm_seq_start,
1206 .next = pwm_seq_next,
1207 .stop = pwm_seq_stop,
1208 .show = pwm_seq_show,
1211 static int pwm_seq_open(struct inode *inode, struct file *file)
1213 return seq_open(file, &pwm_seq_ops);
1216 static const struct file_operations pwm_debugfs_ops = {
1217 .owner = THIS_MODULE,
1218 .open = pwm_seq_open,
1220 .llseek = seq_lseek,
1221 .release = seq_release,
1224 static int __init pwm_debugfs_init(void)
1226 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
1231 subsys_initcall(pwm_debugfs_init);
1232 #endif /* CONFIG_DEBUG_FS */