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>
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);
30 static DEFINE_MUTEX(pwm_lock);
31 static LIST_HEAD(pwm_chips);
32 static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
33 static RADIX_TREE(pwm_tree, GFP_KERNEL);
35 static struct pwm_device *pwm_to_device(unsigned int pwm)
37 return radix_tree_lookup(&pwm_tree, pwm);
40 static int alloc_pwms(unsigned int count)
44 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, 0,
47 if (start + count > MAX_PWMS)
53 static void free_pwms(struct pwm_chip *chip)
57 for (i = 0; i < chip->npwm; i++) {
58 struct pwm_device *pwm = &chip->pwms[i];
60 radix_tree_delete(&pwm_tree, pwm->pwm);
63 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
69 static struct pwm_chip *pwmchip_find_by_name(const char *name)
71 struct pwm_chip *chip;
76 mutex_lock(&pwm_lock);
78 list_for_each_entry(chip, &pwm_chips, list) {
79 const char *chip_name = dev_name(chip->dev);
81 if (chip_name && strcmp(chip_name, name) == 0) {
82 mutex_unlock(&pwm_lock);
87 mutex_unlock(&pwm_lock);
92 static int pwm_device_request(struct pwm_device *pwm, const char *label)
96 if (test_bit(PWMF_REQUESTED, &pwm->flags))
99 if (!try_module_get(pwm->chip->ops->owner))
102 if (pwm->chip->ops->request) {
103 err = pwm->chip->ops->request(pwm->chip, pwm);
105 module_put(pwm->chip->ops->owner);
110 if (pwm->chip->ops->get_state) {
111 pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state);
112 trace_pwm_get(pwm, &pwm->state);
114 if (IS_ENABLED(CONFIG_PWM_DEBUG))
115 pwm->last = pwm->state;
118 set_bit(PWMF_REQUESTED, &pwm->flags);
125 of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
127 struct pwm_device *pwm;
129 if (pc->of_pwm_n_cells < 2)
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 (pc->of_pwm_n_cells >= 3) {
147 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
148 pwm->args.polarity = PWM_POLARITY_INVERSED;
153 EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
155 static void of_pwmchip_add(struct pwm_chip *chip)
157 if (!chip->dev || !chip->dev->of_node)
160 if (!chip->of_xlate) {
163 if (of_property_read_u32(chip->dev->of_node, "#pwm-cells",
167 chip->of_xlate = of_pwm_xlate_with_flags;
168 chip->of_pwm_n_cells = pwm_cells;
171 of_node_get(chip->dev->of_node);
174 static void of_pwmchip_remove(struct pwm_chip *chip)
177 of_node_put(chip->dev->of_node);
181 * pwm_set_chip_data() - set private chip data for a PWM
183 * @data: pointer to chip-specific data
185 * Returns: 0 on success or a negative error code on failure.
187 int pwm_set_chip_data(struct pwm_device *pwm, void *data)
192 pwm->chip_data = data;
196 EXPORT_SYMBOL_GPL(pwm_set_chip_data);
199 * pwm_get_chip_data() - get private chip data for a PWM
202 * Returns: A pointer to the chip-private data for the PWM device.
204 void *pwm_get_chip_data(struct pwm_device *pwm)
206 return pwm ? pwm->chip_data : NULL;
208 EXPORT_SYMBOL_GPL(pwm_get_chip_data);
210 static bool pwm_ops_check(const struct pwm_chip *chip)
213 const struct pwm_ops *ops = chip->ops;
215 /* driver supports legacy, non-atomic operation */
216 if (ops->config && ops->enable && ops->disable) {
217 if (IS_ENABLED(CONFIG_PWM_DEBUG))
219 "Driver needs updating to atomic API\n");
227 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
229 "Please implement the .get_state() callback\n");
235 * pwmchip_add() - register a new PWM chip
236 * @chip: the PWM chip to add
238 * Register a new PWM chip.
240 * Returns: 0 on success or a negative error code on failure.
242 int pwmchip_add(struct pwm_chip *chip)
244 struct pwm_device *pwm;
248 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
251 if (!pwm_ops_check(chip))
254 mutex_lock(&pwm_lock);
256 ret = alloc_pwms(chip->npwm);
262 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
268 for (i = 0; i < chip->npwm; i++) {
269 pwm = &chip->pwms[i];
272 pwm->pwm = chip->base + i;
275 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
278 bitmap_set(allocated_pwms, chip->base, chip->npwm);
280 INIT_LIST_HEAD(&chip->list);
281 list_add(&chip->list, &pwm_chips);
285 if (IS_ENABLED(CONFIG_OF))
286 of_pwmchip_add(chip);
289 mutex_unlock(&pwm_lock);
292 pwmchip_sysfs_export(chip);
296 EXPORT_SYMBOL_GPL(pwmchip_add);
299 * pwmchip_remove() - remove a PWM chip
300 * @chip: the PWM chip to remove
302 * Removes a PWM chip. This function may return busy if the PWM chip provides
303 * a PWM device that is still requested.
305 * Returns: 0 on success or a negative error code on failure.
307 int pwmchip_remove(struct pwm_chip *chip)
309 pwmchip_sysfs_unexport(chip);
311 mutex_lock(&pwm_lock);
313 list_del_init(&chip->list);
315 if (IS_ENABLED(CONFIG_OF))
316 of_pwmchip_remove(chip);
320 mutex_unlock(&pwm_lock);
324 EXPORT_SYMBOL_GPL(pwmchip_remove);
326 static void devm_pwmchip_remove(void *data)
328 struct pwm_chip *chip = data;
330 pwmchip_remove(chip);
333 int devm_pwmchip_add(struct device *dev, struct pwm_chip *chip)
337 ret = pwmchip_add(chip);
341 return devm_add_action_or_reset(dev, devm_pwmchip_remove, chip);
343 EXPORT_SYMBOL_GPL(devm_pwmchip_add);
346 * pwm_request() - request a PWM device
347 * @pwm: global PWM device index
348 * @label: PWM device label
350 * This function is deprecated, use pwm_get() instead.
352 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
355 struct pwm_device *pwm_request(int pwm, const char *label)
357 struct pwm_device *dev;
360 if (pwm < 0 || pwm >= MAX_PWMS)
361 return ERR_PTR(-EINVAL);
363 mutex_lock(&pwm_lock);
365 dev = pwm_to_device(pwm);
367 dev = ERR_PTR(-EPROBE_DEFER);
371 err = pwm_device_request(dev, label);
376 mutex_unlock(&pwm_lock);
380 EXPORT_SYMBOL_GPL(pwm_request);
383 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
385 * @index: per-chip index of the PWM to request
386 * @label: a literal description string of this PWM
388 * Returns: A pointer to the PWM device at the given index of the given PWM
389 * chip. A negative error code is returned if the index is not valid for the
390 * specified PWM chip or if the PWM device cannot be requested.
392 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
396 struct pwm_device *pwm;
399 if (!chip || index >= chip->npwm)
400 return ERR_PTR(-EINVAL);
402 mutex_lock(&pwm_lock);
403 pwm = &chip->pwms[index];
405 err = pwm_device_request(pwm, label);
409 mutex_unlock(&pwm_lock);
412 EXPORT_SYMBOL_GPL(pwm_request_from_chip);
415 * pwm_free() - free a PWM device
418 * This function is deprecated, use pwm_put() instead.
420 void pwm_free(struct pwm_device *pwm)
424 EXPORT_SYMBOL_GPL(pwm_free);
426 static void pwm_apply_state_debug(struct pwm_device *pwm,
427 const struct pwm_state *state)
429 struct pwm_state *last = &pwm->last;
430 struct pwm_chip *chip = pwm->chip;
431 struct pwm_state s1, s2;
434 if (!IS_ENABLED(CONFIG_PWM_DEBUG))
437 /* No reasonable diagnosis possible without .get_state() */
438 if (!chip->ops->get_state)
442 * *state was just applied. Read out the hardware state and do some
446 chip->ops->get_state(chip, pwm, &s1);
447 trace_pwm_get(pwm, &s1);
450 * The lowlevel driver either ignored .polarity (which is a bug) or as
451 * best effort inverted .polarity and fixed .duty_cycle respectively.
452 * Undo this inversion and fixup for further tests.
454 if (s1.enabled && s1.polarity != state->polarity) {
455 s2.polarity = state->polarity;
456 s2.duty_cycle = s1.period - s1.duty_cycle;
457 s2.period = s1.period;
458 s2.enabled = s1.enabled;
463 if (s2.polarity != state->polarity &&
464 state->duty_cycle < state->period)
465 dev_warn(chip->dev, ".apply ignored .polarity\n");
467 if (state->enabled &&
468 last->polarity == state->polarity &&
469 last->period > s2.period &&
470 last->period <= state->period)
472 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
473 state->period, s2.period, last->period);
475 if (state->enabled && state->period < s2.period)
477 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
478 state->period, s2.period);
480 if (state->enabled &&
481 last->polarity == state->polarity &&
482 last->period == s2.period &&
483 last->duty_cycle > s2.duty_cycle &&
484 last->duty_cycle <= state->duty_cycle)
486 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
487 state->duty_cycle, state->period,
488 s2.duty_cycle, s2.period,
489 last->duty_cycle, last->period);
491 if (state->enabled && state->duty_cycle < s2.duty_cycle)
493 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
494 state->duty_cycle, state->period,
495 s2.duty_cycle, s2.period);
497 if (!state->enabled && s2.enabled && s2.duty_cycle > 0)
499 "requested disabled, but yielded enabled with duty > 0\n");
501 /* reapply the state that the driver reported being configured. */
502 err = chip->ops->apply(chip, pwm, &s1);
505 dev_err(chip->dev, "failed to reapply current setting\n");
509 trace_pwm_apply(pwm, &s1);
511 chip->ops->get_state(chip, pwm, last);
512 trace_pwm_get(pwm, last);
514 /* reapplication of the current state should give an exact match */
515 if (s1.enabled != last->enabled ||
516 s1.polarity != last->polarity ||
517 (s1.enabled && s1.period != last->period) ||
518 (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
520 ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
521 s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
522 last->enabled, last->polarity, last->duty_cycle,
528 * pwm_apply_state() - atomically apply a new state to a PWM device
530 * @state: new state to apply
532 int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
534 struct pwm_chip *chip;
537 if (!pwm || !state || !state->period ||
538 state->duty_cycle > state->period)
543 if (state->period == pwm->state.period &&
544 state->duty_cycle == pwm->state.duty_cycle &&
545 state->polarity == pwm->state.polarity &&
546 state->enabled == pwm->state.enabled &&
547 state->usage_power == pwm->state.usage_power)
550 if (chip->ops->apply) {
551 err = chip->ops->apply(chip, pwm, state);
555 trace_pwm_apply(pwm, state);
560 * only do this after pwm->state was applied as some
561 * implementations of .get_state depend on this
563 pwm_apply_state_debug(pwm, state);
566 * FIXME: restore the initial state in case of error.
568 if (state->polarity != pwm->state.polarity) {
569 if (!chip->ops->set_polarity)
573 * Changing the polarity of a running PWM is
574 * only allowed when the PWM driver implements
577 if (pwm->state.enabled) {
578 chip->ops->disable(chip, pwm);
579 pwm->state.enabled = false;
582 err = chip->ops->set_polarity(chip, pwm,
587 pwm->state.polarity = state->polarity;
590 if (state->period != pwm->state.period ||
591 state->duty_cycle != pwm->state.duty_cycle) {
592 err = chip->ops->config(pwm->chip, pwm,
598 pwm->state.duty_cycle = state->duty_cycle;
599 pwm->state.period = state->period;
602 if (state->enabled != pwm->state.enabled) {
603 if (state->enabled) {
604 err = chip->ops->enable(chip, pwm);
608 chip->ops->disable(chip, pwm);
611 pwm->state.enabled = state->enabled;
617 EXPORT_SYMBOL_GPL(pwm_apply_state);
620 * pwm_capture() - capture and report a PWM signal
622 * @result: structure to fill with capture result
623 * @timeout: time to wait, in milliseconds, before giving up on capture
625 * Returns: 0 on success or a negative error code on failure.
627 int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
628 unsigned long timeout)
632 if (!pwm || !pwm->chip->ops)
635 if (!pwm->chip->ops->capture)
638 mutex_lock(&pwm_lock);
639 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
640 mutex_unlock(&pwm_lock);
644 EXPORT_SYMBOL_GPL(pwm_capture);
647 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
650 * This function will adjust the PWM config to the PWM arguments provided
651 * by the DT or PWM lookup table. This is particularly useful to adapt
652 * the bootloader config to the Linux one.
654 int pwm_adjust_config(struct pwm_device *pwm)
656 struct pwm_state state;
657 struct pwm_args pargs;
659 pwm_get_args(pwm, &pargs);
660 pwm_get_state(pwm, &state);
663 * If the current period is zero it means that either the PWM driver
664 * does not support initial state retrieval or the PWM has not yet
667 * In either case, we setup the new period and polarity, and assign a
671 state.duty_cycle = 0;
672 state.period = pargs.period;
673 state.polarity = pargs.polarity;
675 return pwm_apply_state(pwm, &state);
679 * Adjust the PWM duty cycle/period based on the period value provided
682 if (pargs.period != state.period) {
683 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
685 do_div(dutycycle, state.period);
686 state.duty_cycle = dutycycle;
687 state.period = pargs.period;
691 * If the polarity changed, we should also change the duty cycle.
693 if (pargs.polarity != state.polarity) {
694 state.polarity = pargs.polarity;
695 state.duty_cycle = state.period - state.duty_cycle;
698 return pwm_apply_state(pwm, &state);
700 EXPORT_SYMBOL_GPL(pwm_adjust_config);
702 static struct pwm_chip *fwnode_to_pwmchip(struct fwnode_handle *fwnode)
704 struct pwm_chip *chip;
706 mutex_lock(&pwm_lock);
708 list_for_each_entry(chip, &pwm_chips, list)
709 if (chip->dev && dev_fwnode(chip->dev) == fwnode) {
710 mutex_unlock(&pwm_lock);
714 mutex_unlock(&pwm_lock);
716 return ERR_PTR(-EPROBE_DEFER);
719 static struct device_link *pwm_device_link_add(struct device *dev,
720 struct pwm_device *pwm)
722 struct device_link *dl;
726 * No device for the PWM consumer has been provided. It may
727 * impact the PM sequence ordering: the PWM supplier may get
728 * suspended before the consumer.
730 dev_warn(pwm->chip->dev,
731 "No consumer device specified to create a link to\n");
735 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
737 dev_err(dev, "failed to create device link to %s\n",
738 dev_name(pwm->chip->dev));
739 return ERR_PTR(-EINVAL);
746 * of_pwm_get() - request a PWM via the PWM framework
747 * @dev: device for PWM consumer
748 * @np: device node to get the PWM from
749 * @con_id: consumer name
751 * Returns the PWM device parsed from the phandle and index specified in the
752 * "pwms" property of a device tree node or a negative error-code on failure.
753 * Values parsed from the device tree are stored in the returned PWM device
756 * If con_id is NULL, the first PWM device listed in the "pwms" property will
757 * be requested. Otherwise the "pwm-names" property is used to do a reverse
758 * lookup of the PWM index. This also means that the "pwm-names" property
759 * becomes mandatory for devices that look up the PWM device via the con_id
762 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
763 * error code on failure.
765 struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
768 struct pwm_device *pwm = NULL;
769 struct of_phandle_args args;
770 struct device_link *dl;
776 index = of_property_match_string(np, "pwm-names", con_id);
778 return ERR_PTR(index);
781 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
784 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
788 pc = fwnode_to_pwmchip(of_fwnode_handle(args.np));
790 if (PTR_ERR(pc) != -EPROBE_DEFER)
791 pr_err("%s(): PWM chip not found\n", __func__);
797 pwm = pc->of_xlate(pc, &args);
801 dl = pwm_device_link_add(dev, pwm);
803 /* of_xlate ended up calling pwm_request_from_chip() */
810 * If a consumer name was not given, try to look it up from the
811 * "pwm-names" property if it exists. Otherwise use the name of
812 * the user device node.
815 err = of_property_read_string_index(np, "pwm-names", index,
824 of_node_put(args.np);
828 EXPORT_SYMBOL_GPL(of_pwm_get);
830 #if IS_ENABLED(CONFIG_ACPI)
831 static struct pwm_chip *device_to_pwmchip(struct device *dev)
833 struct pwm_chip *chip;
835 mutex_lock(&pwm_lock);
837 list_for_each_entry(chip, &pwm_chips, list) {
838 struct acpi_device *adev = ACPI_COMPANION(chip->dev);
840 if ((chip->dev == dev) || (adev && &adev->dev == dev)) {
841 mutex_unlock(&pwm_lock);
846 mutex_unlock(&pwm_lock);
848 return ERR_PTR(-EPROBE_DEFER);
853 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
854 * @fwnode: firmware node to get the "pwm" property from
856 * Returns the PWM device parsed from the fwnode and index specified in the
857 * "pwms" property or a negative error-code on failure.
858 * Values parsed from the device tree are stored in the returned PWM device
861 * This is analogous to of_pwm_get() except con_id is not yet supported.
862 * ACPI entries must look like
863 * Package () {"pwms", Package ()
864 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
866 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
867 * error code on failure.
869 static struct pwm_device *acpi_pwm_get(struct fwnode_handle *fwnode)
871 struct pwm_device *pwm = ERR_PTR(-ENODEV);
872 #if IS_ENABLED(CONFIG_ACPI)
873 struct fwnode_reference_args args;
874 struct acpi_device *acpi;
875 struct pwm_chip *chip;
878 memset(&args, 0, sizeof(args));
880 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
884 acpi = to_acpi_device_node(args.fwnode);
886 return ERR_PTR(-EINVAL);
889 return ERR_PTR(-EPROTO);
891 chip = device_to_pwmchip(&acpi->dev);
893 return ERR_CAST(chip);
895 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
899 pwm->args.period = args.args[1];
900 pwm->args.polarity = PWM_POLARITY_NORMAL;
902 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
903 pwm->args.polarity = PWM_POLARITY_INVERSED;
910 * pwm_add_table() - register PWM device consumers
911 * @table: array of consumers to register
912 * @num: number of consumers in table
914 void pwm_add_table(struct pwm_lookup *table, size_t num)
916 mutex_lock(&pwm_lookup_lock);
919 list_add_tail(&table->list, &pwm_lookup_list);
923 mutex_unlock(&pwm_lookup_lock);
927 * pwm_remove_table() - unregister PWM device consumers
928 * @table: array of consumers to unregister
929 * @num: number of consumers in table
931 void pwm_remove_table(struct pwm_lookup *table, size_t num)
933 mutex_lock(&pwm_lookup_lock);
936 list_del(&table->list);
940 mutex_unlock(&pwm_lookup_lock);
944 * pwm_get() - look up and request a PWM device
945 * @dev: device for PWM consumer
946 * @con_id: consumer name
948 * Lookup is first attempted using DT. If the device was not instantiated from
949 * a device tree, a PWM chip and a relative index is looked up via a table
950 * supplied by board setup code (see pwm_add_table()).
952 * Once a PWM chip has been found the specified PWM device will be requested
953 * and is ready to be used.
955 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
956 * error code on failure.
958 struct pwm_device *pwm_get(struct device *dev, const char *con_id)
960 const char *dev_id = dev ? dev_name(dev) : NULL;
961 struct pwm_device *pwm;
962 struct pwm_chip *chip;
963 struct device_link *dl;
964 unsigned int best = 0;
965 struct pwm_lookup *p, *chosen = NULL;
969 /* look up via DT first */
970 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
971 return of_pwm_get(dev, dev->of_node, con_id);
973 /* then lookup via ACPI */
974 if (dev && is_acpi_node(dev->fwnode)) {
975 pwm = acpi_pwm_get(dev->fwnode);
976 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
981 * We look up the provider in the static table typically provided by
982 * board setup code. We first try to lookup the consumer device by
983 * name. If the consumer device was passed in as NULL or if no match
984 * was found, we try to find the consumer by directly looking it up
987 * If a match is found, the provider PWM chip is looked up by name
988 * and a PWM device is requested using the PWM device per-chip index.
990 * The lookup algorithm was shamelessly taken from the clock
993 * We do slightly fuzzy matching here:
994 * An entry with a NULL ID is assumed to be a wildcard.
995 * If an entry has a device ID, it must match
996 * If an entry has a connection ID, it must match
997 * Then we take the most specific entry - with the following order
998 * of precedence: dev+con > dev only > con only.
1000 mutex_lock(&pwm_lookup_lock);
1002 list_for_each_entry(p, &pwm_lookup_list, list) {
1006 if (!dev_id || strcmp(p->dev_id, dev_id))
1013 if (!con_id || strcmp(p->con_id, con_id))
1029 mutex_unlock(&pwm_lookup_lock);
1032 return ERR_PTR(-ENODEV);
1034 chip = pwmchip_find_by_name(chosen->provider);
1037 * If the lookup entry specifies a module, load the module and retry
1038 * the PWM chip lookup. This can be used to work around driver load
1039 * ordering issues if driver's can't be made to properly support the
1040 * deferred probe mechanism.
1042 if (!chip && chosen->module) {
1043 err = request_module(chosen->module);
1045 chip = pwmchip_find_by_name(chosen->provider);
1049 return ERR_PTR(-EPROBE_DEFER);
1051 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
1055 dl = pwm_device_link_add(dev, pwm);
1058 return ERR_CAST(dl);
1061 pwm->args.period = chosen->period;
1062 pwm->args.polarity = chosen->polarity;
1066 EXPORT_SYMBOL_GPL(pwm_get);
1069 * pwm_put() - release a PWM device
1072 void pwm_put(struct pwm_device *pwm)
1077 mutex_lock(&pwm_lock);
1079 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
1080 pr_warn("PWM device already freed\n");
1084 if (pwm->chip->ops->free)
1085 pwm->chip->ops->free(pwm->chip, pwm);
1087 pwm_set_chip_data(pwm, NULL);
1090 module_put(pwm->chip->ops->owner);
1092 mutex_unlock(&pwm_lock);
1094 EXPORT_SYMBOL_GPL(pwm_put);
1096 static void devm_pwm_release(struct device *dev, void *res)
1098 pwm_put(*(struct pwm_device **)res);
1102 * devm_pwm_get() - resource managed pwm_get()
1103 * @dev: device for PWM consumer
1104 * @con_id: consumer name
1106 * This function performs like pwm_get() but the acquired PWM device will
1107 * automatically be released on driver detach.
1109 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1110 * error code on failure.
1112 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
1114 struct pwm_device **ptr, *pwm;
1116 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1118 return ERR_PTR(-ENOMEM);
1120 pwm = pwm_get(dev, con_id);
1123 devres_add(dev, ptr);
1130 EXPORT_SYMBOL_GPL(devm_pwm_get);
1133 * devm_of_pwm_get() - resource managed of_pwm_get()
1134 * @dev: device for PWM consumer
1135 * @np: device node to get the PWM from
1136 * @con_id: consumer name
1138 * This function performs like of_pwm_get() but the acquired PWM device will
1139 * automatically be released on driver detach.
1141 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1142 * error code on failure.
1144 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
1147 struct pwm_device **ptr, *pwm;
1149 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1151 return ERR_PTR(-ENOMEM);
1153 pwm = of_pwm_get(dev, np, con_id);
1156 devres_add(dev, ptr);
1163 EXPORT_SYMBOL_GPL(devm_of_pwm_get);
1166 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
1167 * @dev: device for PWM consumer
1168 * @fwnode: firmware node to get the PWM from
1169 * @con_id: consumer name
1171 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
1172 * acpi_pwm_get() for a detailed description.
1174 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1175 * error code on failure.
1177 struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
1178 struct fwnode_handle *fwnode,
1181 struct pwm_device **ptr, *pwm = ERR_PTR(-ENODEV);
1183 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1185 return ERR_PTR(-ENOMEM);
1187 if (is_of_node(fwnode))
1188 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1189 else if (is_acpi_node(fwnode))
1190 pwm = acpi_pwm_get(fwnode);
1194 devres_add(dev, ptr);
1201 EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1203 static int devm_pwm_match(struct device *dev, void *res, void *data)
1205 struct pwm_device **p = res;
1207 if (WARN_ON(!p || !*p))
1214 * devm_pwm_put() - resource managed pwm_put()
1215 * @dev: device for PWM consumer
1218 * Release a PWM previously allocated using devm_pwm_get(). Calling this
1219 * function is usually not needed because devm-allocated resources are
1220 * automatically released on driver detach.
1222 void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
1224 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
1226 EXPORT_SYMBOL_GPL(devm_pwm_put);
1228 #ifdef CONFIG_DEBUG_FS
1229 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1233 for (i = 0; i < chip->npwm; i++) {
1234 struct pwm_device *pwm = &chip->pwms[i];
1235 struct pwm_state state;
1237 pwm_get_state(pwm, &state);
1239 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1241 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1242 seq_puts(s, " requested");
1245 seq_puts(s, " enabled");
1247 seq_printf(s, " period: %llu ns", state.period);
1248 seq_printf(s, " duty: %llu ns", state.duty_cycle);
1249 seq_printf(s, " polarity: %s",
1250 state.polarity ? "inverse" : "normal");
1252 if (state.usage_power)
1253 seq_puts(s, " usage_power");
1259 static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1261 mutex_lock(&pwm_lock);
1264 return seq_list_start(&pwm_chips, *pos);
1267 static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1271 return seq_list_next(v, &pwm_chips, pos);
1274 static void pwm_seq_stop(struct seq_file *s, void *v)
1276 mutex_unlock(&pwm_lock);
1279 static int pwm_seq_show(struct seq_file *s, void *v)
1281 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1283 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1284 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1285 dev_name(chip->dev), chip->npwm,
1286 (chip->npwm != 1) ? "s" : "");
1288 pwm_dbg_show(chip, s);
1293 static const struct seq_operations pwm_debugfs_sops = {
1294 .start = pwm_seq_start,
1295 .next = pwm_seq_next,
1296 .stop = pwm_seq_stop,
1297 .show = pwm_seq_show,
1300 DEFINE_SEQ_ATTRIBUTE(pwm_debugfs);
1302 static int __init pwm_debugfs_init(void)
1304 debugfs_create_file("pwm", S_IFREG | 0444, NULL, NULL,
1309 subsys_initcall(pwm_debugfs_init);
1310 #endif /* CONFIG_DEBUG_FS */