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/idr.h>
13 #include <linux/pwm.h>
14 #include <linux/list.h>
15 #include <linux/mutex.h>
16 #include <linux/err.h>
17 #include <linux/slab.h>
18 #include <linux/device.h>
19 #include <linux/debugfs.h>
20 #include <linux/seq_file.h>
22 #include <dt-bindings/pwm/pwm.h>
24 #define CREATE_TRACE_POINTS
25 #include <trace/events/pwm.h>
27 static DEFINE_MUTEX(pwm_lookup_lock);
28 static LIST_HEAD(pwm_lookup_list);
30 /* protects access to pwm_chips */
31 static DEFINE_MUTEX(pwm_lock);
33 static DEFINE_IDR(pwm_chips);
35 static struct pwm_chip *pwmchip_find_by_name(const char *name)
37 struct pwm_chip *chip;
38 unsigned long id, tmp;
43 mutex_lock(&pwm_lock);
45 idr_for_each_entry_ul(&pwm_chips, chip, tmp, id) {
46 const char *chip_name = dev_name(chip->dev);
48 if (chip_name && strcmp(chip_name, name) == 0) {
49 mutex_unlock(&pwm_lock);
54 mutex_unlock(&pwm_lock);
59 static int pwm_device_request(struct pwm_device *pwm, const char *label)
62 struct pwm_chip *chip = pwm->chip;
63 const struct pwm_ops *ops = chip->ops;
65 if (test_bit(PWMF_REQUESTED, &pwm->flags))
68 if (!try_module_get(chip->owner))
72 err = ops->request(chip, pwm);
74 module_put(chip->owner);
81 * Zero-initialize state because most drivers are unaware of
82 * .usage_power. The other members of state are supposed to be
83 * set by lowlevel drivers. We still initialize the whole
84 * structure for simplicity even though this might paper over
85 * faulty implementations of .get_state().
87 struct pwm_state state = { 0, };
89 err = ops->get_state(chip, pwm, &state);
90 trace_pwm_get(pwm, &state, err);
95 if (IS_ENABLED(CONFIG_PWM_DEBUG))
96 pwm->last = pwm->state;
99 set_bit(PWMF_REQUESTED, &pwm->flags);
106 of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *args)
108 struct pwm_device *pwm;
110 /* period in the second cell and flags in the third cell are optional */
111 if (args->args_count < 1)
112 return ERR_PTR(-EINVAL);
114 pwm = pwm_request_from_chip(chip, args->args[0], NULL);
118 if (args->args_count > 1)
119 pwm->args.period = args->args[1];
121 pwm->args.polarity = PWM_POLARITY_NORMAL;
122 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
123 pwm->args.polarity = PWM_POLARITY_INVERSED;
127 EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
130 of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args)
132 struct pwm_device *pwm;
134 pwm = pwm_request_from_chip(chip, 0, NULL);
138 if (args->args_count > 1)
139 pwm->args.period = args->args[0];
141 pwm->args.polarity = PWM_POLARITY_NORMAL;
142 if (args->args_count > 1 && args->args[1] & PWM_POLARITY_INVERTED)
143 pwm->args.polarity = PWM_POLARITY_INVERSED;
147 EXPORT_SYMBOL_GPL(of_pwm_single_xlate);
149 static void of_pwmchip_add(struct pwm_chip *chip)
151 if (!chip->dev || !chip->dev->of_node)
155 chip->of_xlate = of_pwm_xlate_with_flags;
157 of_node_get(chip->dev->of_node);
160 static void of_pwmchip_remove(struct pwm_chip *chip)
163 of_node_put(chip->dev->of_node);
166 static bool pwm_ops_check(const struct pwm_chip *chip)
168 const struct pwm_ops *ops = chip->ops;
173 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
175 "Please implement the .get_state() callback\n");
181 * __pwmchip_add() - register a new PWM chip
182 * @chip: the PWM chip to add
183 * @owner: reference to the module providing the chip.
185 * Register a new PWM chip. @owner is supposed to be THIS_MODULE, use the
186 * pwmchip_add wrapper to do this right.
188 * Returns: 0 on success or a negative error code on failure.
190 int __pwmchip_add(struct pwm_chip *chip, struct module *owner)
195 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
198 if (!pwm_ops_check(chip))
203 chip->pwms = kcalloc(chip->npwm, sizeof(*chip->pwms), GFP_KERNEL);
207 mutex_lock(&pwm_lock);
209 ret = idr_alloc(&pwm_chips, chip, 0, 0, GFP_KERNEL);
211 mutex_unlock(&pwm_lock);
218 for (i = 0; i < chip->npwm; i++) {
219 struct pwm_device *pwm = &chip->pwms[i];
225 mutex_unlock(&pwm_lock);
227 if (IS_ENABLED(CONFIG_OF))
228 of_pwmchip_add(chip);
230 pwmchip_sysfs_export(chip);
234 EXPORT_SYMBOL_GPL(__pwmchip_add);
237 * pwmchip_remove() - remove a PWM chip
238 * @chip: the PWM chip to remove
240 * Removes a PWM chip.
242 void pwmchip_remove(struct pwm_chip *chip)
244 pwmchip_sysfs_unexport(chip);
246 if (IS_ENABLED(CONFIG_OF))
247 of_pwmchip_remove(chip);
249 mutex_lock(&pwm_lock);
251 idr_remove(&pwm_chips, chip->id);
253 mutex_unlock(&pwm_lock);
257 EXPORT_SYMBOL_GPL(pwmchip_remove);
259 static void devm_pwmchip_remove(void *data)
261 struct pwm_chip *chip = data;
263 pwmchip_remove(chip);
266 int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner)
270 ret = __pwmchip_add(chip, owner);
274 return devm_add_action_or_reset(dev, devm_pwmchip_remove, chip);
276 EXPORT_SYMBOL_GPL(__devm_pwmchip_add);
279 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
281 * @index: per-chip index of the PWM to request
282 * @label: a literal description string of this PWM
284 * Returns: A pointer to the PWM device at the given index of the given PWM
285 * chip. A negative error code is returned if the index is not valid for the
286 * specified PWM chip or if the PWM device cannot be requested.
288 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
292 struct pwm_device *pwm;
295 if (!chip || index >= chip->npwm)
296 return ERR_PTR(-EINVAL);
298 mutex_lock(&pwm_lock);
299 pwm = &chip->pwms[index];
301 err = pwm_device_request(pwm, label);
305 mutex_unlock(&pwm_lock);
308 EXPORT_SYMBOL_GPL(pwm_request_from_chip);
310 static void pwm_apply_debug(struct pwm_device *pwm,
311 const struct pwm_state *state)
313 struct pwm_state *last = &pwm->last;
314 struct pwm_chip *chip = pwm->chip;
315 struct pwm_state s1 = { 0 }, s2 = { 0 };
318 if (!IS_ENABLED(CONFIG_PWM_DEBUG))
321 /* No reasonable diagnosis possible without .get_state() */
322 if (!chip->ops->get_state)
326 * *state was just applied. Read out the hardware state and do some
330 err = chip->ops->get_state(chip, pwm, &s1);
331 trace_pwm_get(pwm, &s1, err);
333 /* If that failed there isn't much to debug */
337 * The lowlevel driver either ignored .polarity (which is a bug) or as
338 * best effort inverted .polarity and fixed .duty_cycle respectively.
339 * Undo this inversion and fixup for further tests.
341 if (s1.enabled && s1.polarity != state->polarity) {
342 s2.polarity = state->polarity;
343 s2.duty_cycle = s1.period - s1.duty_cycle;
344 s2.period = s1.period;
345 s2.enabled = s1.enabled;
350 if (s2.polarity != state->polarity &&
351 state->duty_cycle < state->period)
352 dev_warn(chip->dev, ".apply ignored .polarity\n");
354 if (state->enabled &&
355 last->polarity == state->polarity &&
356 last->period > s2.period &&
357 last->period <= state->period)
359 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
360 state->period, s2.period, last->period);
362 if (state->enabled && state->period < s2.period)
364 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
365 state->period, s2.period);
367 if (state->enabled &&
368 last->polarity == state->polarity &&
369 last->period == s2.period &&
370 last->duty_cycle > s2.duty_cycle &&
371 last->duty_cycle <= state->duty_cycle)
373 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
374 state->duty_cycle, state->period,
375 s2.duty_cycle, s2.period,
376 last->duty_cycle, last->period);
378 if (state->enabled && state->duty_cycle < s2.duty_cycle)
380 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
381 state->duty_cycle, state->period,
382 s2.duty_cycle, s2.period);
384 if (!state->enabled && s2.enabled && s2.duty_cycle > 0)
386 "requested disabled, but yielded enabled with duty > 0\n");
388 /* reapply the state that the driver reported being configured. */
389 err = chip->ops->apply(chip, pwm, &s1);
390 trace_pwm_apply(pwm, &s1, err);
393 dev_err(chip->dev, "failed to reapply current setting\n");
397 *last = (struct pwm_state){ 0 };
398 err = chip->ops->get_state(chip, pwm, last);
399 trace_pwm_get(pwm, last, err);
403 /* reapplication of the current state should give an exact match */
404 if (s1.enabled != last->enabled ||
405 s1.polarity != last->polarity ||
406 (s1.enabled && s1.period != last->period) ||
407 (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
409 ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
410 s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
411 last->enabled, last->polarity, last->duty_cycle,
417 * __pwm_apply() - atomically apply a new state to a PWM device
419 * @state: new state to apply
421 static int __pwm_apply(struct pwm_device *pwm, const struct pwm_state *state)
423 struct pwm_chip *chip;
426 if (!pwm || !state || !state->period ||
427 state->duty_cycle > state->period)
432 if (state->period == pwm->state.period &&
433 state->duty_cycle == pwm->state.duty_cycle &&
434 state->polarity == pwm->state.polarity &&
435 state->enabled == pwm->state.enabled &&
436 state->usage_power == pwm->state.usage_power)
439 err = chip->ops->apply(chip, pwm, state);
440 trace_pwm_apply(pwm, state, err);
447 * only do this after pwm->state was applied as some
448 * implementations of .get_state depend on this
450 pwm_apply_debug(pwm, state);
456 * pwm_apply_might_sleep() - atomically apply a new state to a PWM device
457 * Cannot be used in atomic context.
459 * @state: new state to apply
461 int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state)
466 * Some lowlevel driver's implementations of .apply() make use of
467 * mutexes, also with some drivers only returning when the new
468 * configuration is active calling pwm_apply_might_sleep() from atomic context
469 * is a bad idea. So make it explicit that calling this function might
474 if (IS_ENABLED(CONFIG_PWM_DEBUG) && pwm->chip->atomic) {
476 * Catch any drivers that have been marked as atomic but
477 * that will sleep anyway.
480 err = __pwm_apply(pwm, state);
483 err = __pwm_apply(pwm, state);
488 EXPORT_SYMBOL_GPL(pwm_apply_might_sleep);
491 * pwm_apply_atomic() - apply a new state to a PWM device from atomic context
492 * Not all PWM devices support this function, check with pwm_might_sleep().
494 * @state: new state to apply
496 int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state)
498 WARN_ONCE(!pwm->chip->atomic,
499 "sleeping PWM driver used in atomic context\n");
501 return __pwm_apply(pwm, state);
503 EXPORT_SYMBOL_GPL(pwm_apply_atomic);
506 * pwm_capture() - capture and report a PWM signal
508 * @result: structure to fill with capture result
509 * @timeout: time to wait, in milliseconds, before giving up on capture
511 * Returns: 0 on success or a negative error code on failure.
513 int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
514 unsigned long timeout)
518 if (!pwm || !pwm->chip->ops)
521 if (!pwm->chip->ops->capture)
524 mutex_lock(&pwm_lock);
525 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
526 mutex_unlock(&pwm_lock);
530 EXPORT_SYMBOL_GPL(pwm_capture);
533 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
536 * This function will adjust the PWM config to the PWM arguments provided
537 * by the DT or PWM lookup table. This is particularly useful to adapt
538 * the bootloader config to the Linux one.
540 int pwm_adjust_config(struct pwm_device *pwm)
542 struct pwm_state state;
543 struct pwm_args pargs;
545 pwm_get_args(pwm, &pargs);
546 pwm_get_state(pwm, &state);
549 * If the current period is zero it means that either the PWM driver
550 * does not support initial state retrieval or the PWM has not yet
553 * In either case, we setup the new period and polarity, and assign a
557 state.duty_cycle = 0;
558 state.period = pargs.period;
559 state.polarity = pargs.polarity;
561 return pwm_apply_might_sleep(pwm, &state);
565 * Adjust the PWM duty cycle/period based on the period value provided
568 if (pargs.period != state.period) {
569 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
571 do_div(dutycycle, state.period);
572 state.duty_cycle = dutycycle;
573 state.period = pargs.period;
577 * If the polarity changed, we should also change the duty cycle.
579 if (pargs.polarity != state.polarity) {
580 state.polarity = pargs.polarity;
581 state.duty_cycle = state.period - state.duty_cycle;
584 return pwm_apply_might_sleep(pwm, &state);
586 EXPORT_SYMBOL_GPL(pwm_adjust_config);
588 static struct pwm_chip *fwnode_to_pwmchip(struct fwnode_handle *fwnode)
590 struct pwm_chip *chip;
591 unsigned long id, tmp;
593 mutex_lock(&pwm_lock);
595 idr_for_each_entry_ul(&pwm_chips, chip, tmp, id)
596 if (chip->dev && device_match_fwnode(chip->dev, fwnode)) {
597 mutex_unlock(&pwm_lock);
601 mutex_unlock(&pwm_lock);
603 return ERR_PTR(-EPROBE_DEFER);
606 static struct device_link *pwm_device_link_add(struct device *dev,
607 struct pwm_device *pwm)
609 struct device_link *dl;
613 * No device for the PWM consumer has been provided. It may
614 * impact the PM sequence ordering: the PWM supplier may get
615 * suspended before the consumer.
617 dev_warn(pwm->chip->dev,
618 "No consumer device specified to create a link to\n");
622 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
624 dev_err(dev, "failed to create device link to %s\n",
625 dev_name(pwm->chip->dev));
626 return ERR_PTR(-EINVAL);
633 * of_pwm_get() - request a PWM via the PWM framework
634 * @dev: device for PWM consumer
635 * @np: device node to get the PWM from
636 * @con_id: consumer name
638 * Returns the PWM device parsed from the phandle and index specified in the
639 * "pwms" property of a device tree node or a negative error-code on failure.
640 * Values parsed from the device tree are stored in the returned PWM device
643 * If con_id is NULL, the first PWM device listed in the "pwms" property will
644 * be requested. Otherwise the "pwm-names" property is used to do a reverse
645 * lookup of the PWM index. This also means that the "pwm-names" property
646 * becomes mandatory for devices that look up the PWM device via the con_id
649 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
650 * error code on failure.
652 static struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
655 struct pwm_device *pwm = NULL;
656 struct of_phandle_args args;
657 struct device_link *dl;
658 struct pwm_chip *chip;
663 index = of_property_match_string(np, "pwm-names", con_id);
665 return ERR_PTR(index);
668 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
671 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
675 chip = fwnode_to_pwmchip(of_fwnode_handle(args.np));
677 if (PTR_ERR(chip) != -EPROBE_DEFER)
678 pr_err("%s(): PWM chip not found\n", __func__);
680 pwm = ERR_CAST(chip);
684 pwm = chip->of_xlate(chip, &args);
688 dl = pwm_device_link_add(dev, pwm);
690 /* of_xlate ended up calling pwm_request_from_chip() */
697 * If a consumer name was not given, try to look it up from the
698 * "pwm-names" property if it exists. Otherwise use the name of
699 * the user device node.
702 err = of_property_read_string_index(np, "pwm-names", index,
711 of_node_put(args.np);
717 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
718 * @fwnode: firmware node to get the "pwms" property from
720 * Returns the PWM device parsed from the fwnode and index specified in the
721 * "pwms" property or a negative error-code on failure.
722 * Values parsed from the device tree are stored in the returned PWM device
725 * This is analogous to of_pwm_get() except con_id is not yet supported.
726 * ACPI entries must look like
727 * Package () {"pwms", Package ()
728 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
730 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
731 * error code on failure.
733 static struct pwm_device *acpi_pwm_get(const struct fwnode_handle *fwnode)
735 struct pwm_device *pwm;
736 struct fwnode_reference_args args;
737 struct pwm_chip *chip;
740 memset(&args, 0, sizeof(args));
742 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
747 return ERR_PTR(-EPROTO);
749 chip = fwnode_to_pwmchip(args.fwnode);
751 return ERR_CAST(chip);
753 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
757 pwm->args.period = args.args[1];
758 pwm->args.polarity = PWM_POLARITY_NORMAL;
760 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
761 pwm->args.polarity = PWM_POLARITY_INVERSED;
767 * pwm_add_table() - register PWM device consumers
768 * @table: array of consumers to register
769 * @num: number of consumers in table
771 void pwm_add_table(struct pwm_lookup *table, size_t num)
773 mutex_lock(&pwm_lookup_lock);
776 list_add_tail(&table->list, &pwm_lookup_list);
780 mutex_unlock(&pwm_lookup_lock);
784 * pwm_remove_table() - unregister PWM device consumers
785 * @table: array of consumers to unregister
786 * @num: number of consumers in table
788 void pwm_remove_table(struct pwm_lookup *table, size_t num)
790 mutex_lock(&pwm_lookup_lock);
793 list_del(&table->list);
797 mutex_unlock(&pwm_lookup_lock);
801 * pwm_get() - look up and request a PWM device
802 * @dev: device for PWM consumer
803 * @con_id: consumer name
805 * Lookup is first attempted using DT. If the device was not instantiated from
806 * a device tree, a PWM chip and a relative index is looked up via a table
807 * supplied by board setup code (see pwm_add_table()).
809 * Once a PWM chip has been found the specified PWM device will be requested
810 * and is ready to be used.
812 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
813 * error code on failure.
815 struct pwm_device *pwm_get(struct device *dev, const char *con_id)
817 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
818 const char *dev_id = dev ? dev_name(dev) : NULL;
819 struct pwm_device *pwm;
820 struct pwm_chip *chip;
821 struct device_link *dl;
822 unsigned int best = 0;
823 struct pwm_lookup *p, *chosen = NULL;
827 /* look up via DT first */
828 if (is_of_node(fwnode))
829 return of_pwm_get(dev, to_of_node(fwnode), con_id);
831 /* then lookup via ACPI */
832 if (is_acpi_node(fwnode)) {
833 pwm = acpi_pwm_get(fwnode);
834 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
839 * We look up the provider in the static table typically provided by
840 * board setup code. We first try to lookup the consumer device by
841 * name. If the consumer device was passed in as NULL or if no match
842 * was found, we try to find the consumer by directly looking it up
845 * If a match is found, the provider PWM chip is looked up by name
846 * and a PWM device is requested using the PWM device per-chip index.
848 * The lookup algorithm was shamelessly taken from the clock
851 * We do slightly fuzzy matching here:
852 * An entry with a NULL ID is assumed to be a wildcard.
853 * If an entry has a device ID, it must match
854 * If an entry has a connection ID, it must match
855 * Then we take the most specific entry - with the following order
856 * of precedence: dev+con > dev only > con only.
858 mutex_lock(&pwm_lookup_lock);
860 list_for_each_entry(p, &pwm_lookup_list, list) {
864 if (!dev_id || strcmp(p->dev_id, dev_id))
871 if (!con_id || strcmp(p->con_id, con_id))
887 mutex_unlock(&pwm_lookup_lock);
890 return ERR_PTR(-ENODEV);
892 chip = pwmchip_find_by_name(chosen->provider);
895 * If the lookup entry specifies a module, load the module and retry
896 * the PWM chip lookup. This can be used to work around driver load
897 * ordering issues if driver's can't be made to properly support the
898 * deferred probe mechanism.
900 if (!chip && chosen->module) {
901 err = request_module(chosen->module);
903 chip = pwmchip_find_by_name(chosen->provider);
907 return ERR_PTR(-EPROBE_DEFER);
909 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
913 dl = pwm_device_link_add(dev, pwm);
919 pwm->args.period = chosen->period;
920 pwm->args.polarity = chosen->polarity;
924 EXPORT_SYMBOL_GPL(pwm_get);
927 * pwm_put() - release a PWM device
930 void pwm_put(struct pwm_device *pwm)
935 mutex_lock(&pwm_lock);
937 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
938 pr_warn("PWM device already freed\n");
942 if (pwm->chip->ops->free)
943 pwm->chip->ops->free(pwm->chip, pwm);
947 module_put(pwm->chip->owner);
949 mutex_unlock(&pwm_lock);
951 EXPORT_SYMBOL_GPL(pwm_put);
953 static void devm_pwm_release(void *pwm)
959 * devm_pwm_get() - resource managed pwm_get()
960 * @dev: device for PWM consumer
961 * @con_id: consumer name
963 * This function performs like pwm_get() but the acquired PWM device will
964 * automatically be released on driver detach.
966 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
967 * error code on failure.
969 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
971 struct pwm_device *pwm;
974 pwm = pwm_get(dev, con_id);
978 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
984 EXPORT_SYMBOL_GPL(devm_pwm_get);
987 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
988 * @dev: device for PWM consumer
989 * @fwnode: firmware node to get the PWM from
990 * @con_id: consumer name
992 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
993 * acpi_pwm_get() for a detailed description.
995 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
996 * error code on failure.
998 struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
999 struct fwnode_handle *fwnode,
1002 struct pwm_device *pwm = ERR_PTR(-ENODEV);
1005 if (is_of_node(fwnode))
1006 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1007 else if (is_acpi_node(fwnode))
1008 pwm = acpi_pwm_get(fwnode);
1012 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
1014 return ERR_PTR(ret);
1018 EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1020 #ifdef CONFIG_DEBUG_FS
1021 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1025 for (i = 0; i < chip->npwm; i++) {
1026 struct pwm_device *pwm = &chip->pwms[i];
1027 struct pwm_state state;
1029 pwm_get_state(pwm, &state);
1031 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1033 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1034 seq_puts(s, " requested");
1037 seq_puts(s, " enabled");
1039 seq_printf(s, " period: %llu ns", state.period);
1040 seq_printf(s, " duty: %llu ns", state.duty_cycle);
1041 seq_printf(s, " polarity: %s",
1042 state.polarity ? "inverse" : "normal");
1044 if (state.usage_power)
1045 seq_puts(s, " usage_power");
1051 static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1053 unsigned long id = *pos;
1056 mutex_lock(&pwm_lock);
1059 ret = idr_get_next_ul(&pwm_chips, &id);
1064 static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1066 unsigned long id = *pos + 1;
1071 ret = idr_get_next_ul(&pwm_chips, &id);
1076 static void pwm_seq_stop(struct seq_file *s, void *v)
1078 mutex_unlock(&pwm_lock);
1081 static int pwm_seq_show(struct seq_file *s, void *v)
1083 struct pwm_chip *chip = v;
1085 seq_printf(s, "%s%d: %s/%s, %d PWM device%s\n",
1086 (char *)s->private, chip->id,
1087 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1088 dev_name(chip->dev), chip->npwm,
1089 (chip->npwm != 1) ? "s" : "");
1091 pwm_dbg_show(chip, s);
1096 static const struct seq_operations pwm_debugfs_sops = {
1097 .start = pwm_seq_start,
1098 .next = pwm_seq_next,
1099 .stop = pwm_seq_stop,
1100 .show = pwm_seq_show,
1103 DEFINE_SEQ_ATTRIBUTE(pwm_debugfs);
1105 static int __init pwm_debugfs_init(void)
1107 debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops);
1111 subsys_initcall(pwm_debugfs_init);
1112 #endif /* CONFIG_DEBUG_FS */