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>
12 #include <linux/pwm.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>
23 #define CREATE_TRACE_POINTS
24 #include <trace/events/pwm.h>
28 static DEFINE_MUTEX(pwm_lookup_lock);
29 static LIST_HEAD(pwm_lookup_list);
31 /* protects access to pwm_chips and allocated_pwms */
32 static DEFINE_MUTEX(pwm_lock);
34 static LIST_HEAD(pwm_chips);
35 static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
37 /* Called with pwm_lock held */
38 static int alloc_pwms(unsigned int count)
42 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, 0,
45 if (start + count > MAX_PWMS)
48 bitmap_set(allocated_pwms, start, count);
53 /* Called with pwm_lock held */
54 static void free_pwms(struct pwm_chip *chip)
56 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
62 static struct pwm_chip *pwmchip_find_by_name(const char *name)
64 struct pwm_chip *chip;
69 mutex_lock(&pwm_lock);
71 list_for_each_entry(chip, &pwm_chips, list) {
72 const char *chip_name = dev_name(chip->dev);
74 if (chip_name && strcmp(chip_name, name) == 0) {
75 mutex_unlock(&pwm_lock);
80 mutex_unlock(&pwm_lock);
85 static int pwm_device_request(struct pwm_device *pwm, const char *label)
89 if (test_bit(PWMF_REQUESTED, &pwm->flags))
92 if (!try_module_get(pwm->chip->owner))
95 if (pwm->chip->ops->request) {
96 err = pwm->chip->ops->request(pwm->chip, pwm);
98 module_put(pwm->chip->owner);
103 if (pwm->chip->ops->get_state) {
105 * Zero-initialize state because most drivers are unaware of
106 * .usage_power. The other members of state are supposed to be
107 * set by lowlevel drivers. We still initialize the whole
108 * structure for simplicity even though this might paper over
109 * faulty implementations of .get_state().
111 struct pwm_state state = { 0, };
113 err = pwm->chip->ops->get_state(pwm->chip, pwm, &state);
114 trace_pwm_get(pwm, &state, err);
119 if (IS_ENABLED(CONFIG_PWM_DEBUG))
120 pwm->last = pwm->state;
123 set_bit(PWMF_REQUESTED, &pwm->flags);
130 of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *args)
132 struct pwm_device *pwm;
134 if (chip->of_pwm_n_cells < 2)
135 return ERR_PTR(-EINVAL);
137 /* flags in the third cell are optional */
138 if (args->args_count < 2)
139 return ERR_PTR(-EINVAL);
141 if (args->args[0] >= chip->npwm)
142 return ERR_PTR(-EINVAL);
144 pwm = pwm_request_from_chip(chip, args->args[0], NULL);
148 pwm->args.period = args->args[1];
149 pwm->args.polarity = PWM_POLARITY_NORMAL;
151 if (chip->of_pwm_n_cells >= 3) {
152 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
153 pwm->args.polarity = PWM_POLARITY_INVERSED;
158 EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
161 of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args)
163 struct pwm_device *pwm;
165 if (chip->of_pwm_n_cells < 1)
166 return ERR_PTR(-EINVAL);
168 /* validate that one cell is specified, optionally with flags */
169 if (args->args_count != 1 && args->args_count != 2)
170 return ERR_PTR(-EINVAL);
172 pwm = pwm_request_from_chip(chip, 0, NULL);
176 pwm->args.period = args->args[0];
177 pwm->args.polarity = PWM_POLARITY_NORMAL;
179 if (args->args_count == 2 && args->args[1] & PWM_POLARITY_INVERTED)
180 pwm->args.polarity = PWM_POLARITY_INVERSED;
184 EXPORT_SYMBOL_GPL(of_pwm_single_xlate);
186 static void of_pwmchip_add(struct pwm_chip *chip)
188 if (!chip->dev || !chip->dev->of_node)
191 if (!chip->of_xlate) {
194 if (of_property_read_u32(chip->dev->of_node, "#pwm-cells",
198 chip->of_xlate = of_pwm_xlate_with_flags;
199 chip->of_pwm_n_cells = pwm_cells;
202 of_node_get(chip->dev->of_node);
205 static void of_pwmchip_remove(struct pwm_chip *chip)
208 of_node_put(chip->dev->of_node);
211 static bool pwm_ops_check(const struct pwm_chip *chip)
213 const struct pwm_ops *ops = chip->ops;
218 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
220 "Please implement the .get_state() callback\n");
226 * __pwmchip_add() - register a new PWM chip
227 * @chip: the PWM chip to add
228 * @owner: reference to the module providing the chip.
230 * Register a new PWM chip. @owner is supposed to be THIS_MODULE, use the
231 * pwmchip_add wrapper to do this right.
233 * Returns: 0 on success or a negative error code on failure.
235 int __pwmchip_add(struct pwm_chip *chip, struct module *owner)
237 struct pwm_device *pwm;
241 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
244 if (!pwm_ops_check(chip))
249 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
253 mutex_lock(&pwm_lock);
255 ret = alloc_pwms(chip->npwm);
257 mutex_unlock(&pwm_lock);
264 for (i = 0; i < chip->npwm; i++) {
265 pwm = &chip->pwms[i];
268 pwm->pwm = chip->base + i;
272 list_add(&chip->list, &pwm_chips);
274 mutex_unlock(&pwm_lock);
276 if (IS_ENABLED(CONFIG_OF))
277 of_pwmchip_add(chip);
279 pwmchip_sysfs_export(chip);
283 EXPORT_SYMBOL_GPL(__pwmchip_add);
286 * pwmchip_remove() - remove a PWM chip
287 * @chip: the PWM chip to remove
289 * Removes a PWM chip.
291 void pwmchip_remove(struct pwm_chip *chip)
293 pwmchip_sysfs_unexport(chip);
295 if (IS_ENABLED(CONFIG_OF))
296 of_pwmchip_remove(chip);
298 mutex_lock(&pwm_lock);
300 list_del_init(&chip->list);
304 mutex_unlock(&pwm_lock);
306 EXPORT_SYMBOL_GPL(pwmchip_remove);
308 static void devm_pwmchip_remove(void *data)
310 struct pwm_chip *chip = data;
312 pwmchip_remove(chip);
315 int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner)
319 ret = __pwmchip_add(chip, owner);
323 return devm_add_action_or_reset(dev, devm_pwmchip_remove, chip);
325 EXPORT_SYMBOL_GPL(__devm_pwmchip_add);
328 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
330 * @index: per-chip index of the PWM to request
331 * @label: a literal description string of this PWM
333 * Returns: A pointer to the PWM device at the given index of the given PWM
334 * chip. A negative error code is returned if the index is not valid for the
335 * specified PWM chip or if the PWM device cannot be requested.
337 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
341 struct pwm_device *pwm;
344 if (!chip || index >= chip->npwm)
345 return ERR_PTR(-EINVAL);
347 mutex_lock(&pwm_lock);
348 pwm = &chip->pwms[index];
350 err = pwm_device_request(pwm, label);
354 mutex_unlock(&pwm_lock);
357 EXPORT_SYMBOL_GPL(pwm_request_from_chip);
359 static void pwm_apply_state_debug(struct pwm_device *pwm,
360 const struct pwm_state *state)
362 struct pwm_state *last = &pwm->last;
363 struct pwm_chip *chip = pwm->chip;
364 struct pwm_state s1 = { 0 }, s2 = { 0 };
367 if (!IS_ENABLED(CONFIG_PWM_DEBUG))
370 /* No reasonable diagnosis possible without .get_state() */
371 if (!chip->ops->get_state)
375 * *state was just applied. Read out the hardware state and do some
379 err = chip->ops->get_state(chip, pwm, &s1);
380 trace_pwm_get(pwm, &s1, err);
382 /* If that failed there isn't much to debug */
386 * The lowlevel driver either ignored .polarity (which is a bug) or as
387 * best effort inverted .polarity and fixed .duty_cycle respectively.
388 * Undo this inversion and fixup for further tests.
390 if (s1.enabled && s1.polarity != state->polarity) {
391 s2.polarity = state->polarity;
392 s2.duty_cycle = s1.period - s1.duty_cycle;
393 s2.period = s1.period;
394 s2.enabled = s1.enabled;
399 if (s2.polarity != state->polarity &&
400 state->duty_cycle < state->period)
401 dev_warn(chip->dev, ".apply ignored .polarity\n");
403 if (state->enabled &&
404 last->polarity == state->polarity &&
405 last->period > s2.period &&
406 last->period <= state->period)
408 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
409 state->period, s2.period, last->period);
411 if (state->enabled && state->period < s2.period)
413 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
414 state->period, s2.period);
416 if (state->enabled &&
417 last->polarity == state->polarity &&
418 last->period == s2.period &&
419 last->duty_cycle > s2.duty_cycle &&
420 last->duty_cycle <= state->duty_cycle)
422 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
423 state->duty_cycle, state->period,
424 s2.duty_cycle, s2.period,
425 last->duty_cycle, last->period);
427 if (state->enabled && state->duty_cycle < s2.duty_cycle)
429 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
430 state->duty_cycle, state->period,
431 s2.duty_cycle, s2.period);
433 if (!state->enabled && s2.enabled && s2.duty_cycle > 0)
435 "requested disabled, but yielded enabled with duty > 0\n");
437 /* reapply the state that the driver reported being configured. */
438 err = chip->ops->apply(chip, pwm, &s1);
439 trace_pwm_apply(pwm, &s1, err);
442 dev_err(chip->dev, "failed to reapply current setting\n");
446 *last = (struct pwm_state){ 0 };
447 err = chip->ops->get_state(chip, pwm, last);
448 trace_pwm_get(pwm, last, err);
452 /* reapplication of the current state should give an exact match */
453 if (s1.enabled != last->enabled ||
454 s1.polarity != last->polarity ||
455 (s1.enabled && s1.period != last->period) ||
456 (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
458 ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
459 s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
460 last->enabled, last->polarity, last->duty_cycle,
466 * pwm_apply_state() - atomically apply a new state to a PWM device
468 * @state: new state to apply
470 int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
472 struct pwm_chip *chip;
476 * Some lowlevel driver's implementations of .apply() make use of
477 * mutexes, also with some drivers only returning when the new
478 * configuration is active calling pwm_apply_state() from atomic context
479 * is a bad idea. So make it explicit that calling this function might
484 if (!pwm || !state || !state->period ||
485 state->duty_cycle > state->period)
490 if (state->period == pwm->state.period &&
491 state->duty_cycle == pwm->state.duty_cycle &&
492 state->polarity == pwm->state.polarity &&
493 state->enabled == pwm->state.enabled &&
494 state->usage_power == pwm->state.usage_power)
497 err = chip->ops->apply(chip, pwm, state);
498 trace_pwm_apply(pwm, state, err);
505 * only do this after pwm->state was applied as some
506 * implementations of .get_state depend on this
508 pwm_apply_state_debug(pwm, state);
512 EXPORT_SYMBOL_GPL(pwm_apply_state);
515 * pwm_capture() - capture and report a PWM signal
517 * @result: structure to fill with capture result
518 * @timeout: time to wait, in milliseconds, before giving up on capture
520 * Returns: 0 on success or a negative error code on failure.
522 int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
523 unsigned long timeout)
527 if (!pwm || !pwm->chip->ops)
530 if (!pwm->chip->ops->capture)
533 mutex_lock(&pwm_lock);
534 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
535 mutex_unlock(&pwm_lock);
539 EXPORT_SYMBOL_GPL(pwm_capture);
542 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
545 * This function will adjust the PWM config to the PWM arguments provided
546 * by the DT or PWM lookup table. This is particularly useful to adapt
547 * the bootloader config to the Linux one.
549 int pwm_adjust_config(struct pwm_device *pwm)
551 struct pwm_state state;
552 struct pwm_args pargs;
554 pwm_get_args(pwm, &pargs);
555 pwm_get_state(pwm, &state);
558 * If the current period is zero it means that either the PWM driver
559 * does not support initial state retrieval or the PWM has not yet
562 * In either case, we setup the new period and polarity, and assign a
566 state.duty_cycle = 0;
567 state.period = pargs.period;
568 state.polarity = pargs.polarity;
570 return pwm_apply_state(pwm, &state);
574 * Adjust the PWM duty cycle/period based on the period value provided
577 if (pargs.period != state.period) {
578 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
580 do_div(dutycycle, state.period);
581 state.duty_cycle = dutycycle;
582 state.period = pargs.period;
586 * If the polarity changed, we should also change the duty cycle.
588 if (pargs.polarity != state.polarity) {
589 state.polarity = pargs.polarity;
590 state.duty_cycle = state.period - state.duty_cycle;
593 return pwm_apply_state(pwm, &state);
595 EXPORT_SYMBOL_GPL(pwm_adjust_config);
597 static struct pwm_chip *fwnode_to_pwmchip(struct fwnode_handle *fwnode)
599 struct pwm_chip *chip;
601 mutex_lock(&pwm_lock);
603 list_for_each_entry(chip, &pwm_chips, list)
604 if (chip->dev && device_match_fwnode(chip->dev, fwnode)) {
605 mutex_unlock(&pwm_lock);
609 mutex_unlock(&pwm_lock);
611 return ERR_PTR(-EPROBE_DEFER);
614 static struct device_link *pwm_device_link_add(struct device *dev,
615 struct pwm_device *pwm)
617 struct device_link *dl;
621 * No device for the PWM consumer has been provided. It may
622 * impact the PM sequence ordering: the PWM supplier may get
623 * suspended before the consumer.
625 dev_warn(pwm->chip->dev,
626 "No consumer device specified to create a link to\n");
630 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
632 dev_err(dev, "failed to create device link to %s\n",
633 dev_name(pwm->chip->dev));
634 return ERR_PTR(-EINVAL);
641 * of_pwm_get() - request a PWM via the PWM framework
642 * @dev: device for PWM consumer
643 * @np: device node to get the PWM from
644 * @con_id: consumer name
646 * Returns the PWM device parsed from the phandle and index specified in the
647 * "pwms" property of a device tree node or a negative error-code on failure.
648 * Values parsed from the device tree are stored in the returned PWM device
651 * If con_id is NULL, the first PWM device listed in the "pwms" property will
652 * be requested. Otherwise the "pwm-names" property is used to do a reverse
653 * lookup of the PWM index. This also means that the "pwm-names" property
654 * becomes mandatory for devices that look up the PWM device via the con_id
657 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
658 * error code on failure.
660 static struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
663 struct pwm_device *pwm = NULL;
664 struct of_phandle_args args;
665 struct device_link *dl;
666 struct pwm_chip *chip;
671 index = of_property_match_string(np, "pwm-names", con_id);
673 return ERR_PTR(index);
676 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
679 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
683 chip = fwnode_to_pwmchip(of_fwnode_handle(args.np));
685 if (PTR_ERR(chip) != -EPROBE_DEFER)
686 pr_err("%s(): PWM chip not found\n", __func__);
688 pwm = ERR_CAST(chip);
692 pwm = chip->of_xlate(chip, &args);
696 dl = pwm_device_link_add(dev, pwm);
698 /* of_xlate ended up calling pwm_request_from_chip() */
705 * If a consumer name was not given, try to look it up from the
706 * "pwm-names" property if it exists. Otherwise use the name of
707 * the user device node.
710 err = of_property_read_string_index(np, "pwm-names", index,
719 of_node_put(args.np);
725 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
726 * @fwnode: firmware node to get the "pwms" property from
728 * Returns the PWM device parsed from the fwnode and index specified in the
729 * "pwms" property or a negative error-code on failure.
730 * Values parsed from the device tree are stored in the returned PWM device
733 * This is analogous to of_pwm_get() except con_id is not yet supported.
734 * ACPI entries must look like
735 * Package () {"pwms", Package ()
736 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
738 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
739 * error code on failure.
741 static struct pwm_device *acpi_pwm_get(const struct fwnode_handle *fwnode)
743 struct pwm_device *pwm;
744 struct fwnode_reference_args args;
745 struct pwm_chip *chip;
748 memset(&args, 0, sizeof(args));
750 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
755 return ERR_PTR(-EPROTO);
757 chip = fwnode_to_pwmchip(args.fwnode);
759 return ERR_CAST(chip);
761 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
765 pwm->args.period = args.args[1];
766 pwm->args.polarity = PWM_POLARITY_NORMAL;
768 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
769 pwm->args.polarity = PWM_POLARITY_INVERSED;
775 * pwm_add_table() - register PWM device consumers
776 * @table: array of consumers to register
777 * @num: number of consumers in table
779 void pwm_add_table(struct pwm_lookup *table, size_t num)
781 mutex_lock(&pwm_lookup_lock);
784 list_add_tail(&table->list, &pwm_lookup_list);
788 mutex_unlock(&pwm_lookup_lock);
792 * pwm_remove_table() - unregister PWM device consumers
793 * @table: array of consumers to unregister
794 * @num: number of consumers in table
796 void pwm_remove_table(struct pwm_lookup *table, size_t num)
798 mutex_lock(&pwm_lookup_lock);
801 list_del(&table->list);
805 mutex_unlock(&pwm_lookup_lock);
809 * pwm_get() - look up and request a PWM device
810 * @dev: device for PWM consumer
811 * @con_id: consumer name
813 * Lookup is first attempted using DT. If the device was not instantiated from
814 * a device tree, a PWM chip and a relative index is looked up via a table
815 * supplied by board setup code (see pwm_add_table()).
817 * Once a PWM chip has been found the specified PWM device will be requested
818 * and is ready to be used.
820 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
821 * error code on failure.
823 struct pwm_device *pwm_get(struct device *dev, const char *con_id)
825 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
826 const char *dev_id = dev ? dev_name(dev) : NULL;
827 struct pwm_device *pwm;
828 struct pwm_chip *chip;
829 struct device_link *dl;
830 unsigned int best = 0;
831 struct pwm_lookup *p, *chosen = NULL;
835 /* look up via DT first */
836 if (is_of_node(fwnode))
837 return of_pwm_get(dev, to_of_node(fwnode), con_id);
839 /* then lookup via ACPI */
840 if (is_acpi_node(fwnode)) {
841 pwm = acpi_pwm_get(fwnode);
842 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
847 * We look up the provider in the static table typically provided by
848 * board setup code. We first try to lookup the consumer device by
849 * name. If the consumer device was passed in as NULL or if no match
850 * was found, we try to find the consumer by directly looking it up
853 * If a match is found, the provider PWM chip is looked up by name
854 * and a PWM device is requested using the PWM device per-chip index.
856 * The lookup algorithm was shamelessly taken from the clock
859 * We do slightly fuzzy matching here:
860 * An entry with a NULL ID is assumed to be a wildcard.
861 * If an entry has a device ID, it must match
862 * If an entry has a connection ID, it must match
863 * Then we take the most specific entry - with the following order
864 * of precedence: dev+con > dev only > con only.
866 mutex_lock(&pwm_lookup_lock);
868 list_for_each_entry(p, &pwm_lookup_list, list) {
872 if (!dev_id || strcmp(p->dev_id, dev_id))
879 if (!con_id || strcmp(p->con_id, con_id))
895 mutex_unlock(&pwm_lookup_lock);
898 return ERR_PTR(-ENODEV);
900 chip = pwmchip_find_by_name(chosen->provider);
903 * If the lookup entry specifies a module, load the module and retry
904 * the PWM chip lookup. This can be used to work around driver load
905 * ordering issues if driver's can't be made to properly support the
906 * deferred probe mechanism.
908 if (!chip && chosen->module) {
909 err = request_module(chosen->module);
911 chip = pwmchip_find_by_name(chosen->provider);
915 return ERR_PTR(-EPROBE_DEFER);
917 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
921 dl = pwm_device_link_add(dev, pwm);
927 pwm->args.period = chosen->period;
928 pwm->args.polarity = chosen->polarity;
932 EXPORT_SYMBOL_GPL(pwm_get);
935 * pwm_put() - release a PWM device
938 void pwm_put(struct pwm_device *pwm)
943 mutex_lock(&pwm_lock);
945 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
946 pr_warn("PWM device already freed\n");
950 if (pwm->chip->ops->free)
951 pwm->chip->ops->free(pwm->chip, pwm);
955 module_put(pwm->chip->owner);
957 mutex_unlock(&pwm_lock);
959 EXPORT_SYMBOL_GPL(pwm_put);
961 static void devm_pwm_release(void *pwm)
967 * devm_pwm_get() - resource managed pwm_get()
968 * @dev: device for PWM consumer
969 * @con_id: consumer name
971 * This function performs like pwm_get() but the acquired PWM device will
972 * automatically be released on driver detach.
974 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
975 * error code on failure.
977 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
979 struct pwm_device *pwm;
982 pwm = pwm_get(dev, con_id);
986 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
992 EXPORT_SYMBOL_GPL(devm_pwm_get);
995 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
996 * @dev: device for PWM consumer
997 * @fwnode: firmware node to get the PWM from
998 * @con_id: consumer name
1000 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
1001 * acpi_pwm_get() for a detailed description.
1003 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1004 * error code on failure.
1006 struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
1007 struct fwnode_handle *fwnode,
1010 struct pwm_device *pwm = ERR_PTR(-ENODEV);
1013 if (is_of_node(fwnode))
1014 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1015 else if (is_acpi_node(fwnode))
1016 pwm = acpi_pwm_get(fwnode);
1020 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
1022 return ERR_PTR(ret);
1026 EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1028 #ifdef CONFIG_DEBUG_FS
1029 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1033 for (i = 0; i < chip->npwm; i++) {
1034 struct pwm_device *pwm = &chip->pwms[i];
1035 struct pwm_state state;
1037 pwm_get_state(pwm, &state);
1039 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1041 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1042 seq_puts(s, " requested");
1045 seq_puts(s, " enabled");
1047 seq_printf(s, " period: %llu ns", state.period);
1048 seq_printf(s, " duty: %llu ns", state.duty_cycle);
1049 seq_printf(s, " polarity: %s",
1050 state.polarity ? "inverse" : "normal");
1052 if (state.usage_power)
1053 seq_puts(s, " usage_power");
1059 static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1061 mutex_lock(&pwm_lock);
1064 return seq_list_start(&pwm_chips, *pos);
1067 static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1071 return seq_list_next(v, &pwm_chips, pos);
1074 static void pwm_seq_stop(struct seq_file *s, void *v)
1076 mutex_unlock(&pwm_lock);
1079 static int pwm_seq_show(struct seq_file *s, void *v)
1081 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1083 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1084 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1085 dev_name(chip->dev), chip->npwm,
1086 (chip->npwm != 1) ? "s" : "");
1088 pwm_dbg_show(chip, s);
1093 static const struct seq_operations pwm_debugfs_sops = {
1094 .start = pwm_seq_start,
1095 .next = pwm_seq_next,
1096 .stop = pwm_seq_stop,
1097 .show = pwm_seq_show,
1100 DEFINE_SEQ_ATTRIBUTE(pwm_debugfs);
1102 static int __init pwm_debugfs_init(void)
1104 debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops);
1108 subsys_initcall(pwm_debugfs_init);
1109 #endif /* CONFIG_DEBUG_FS */