| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Generic pwmlib implementation |
| * |
| * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de> |
| * Copyright (C) 2011-2012 Avionic Design GmbH |
| */ |
| |
| #include <linux/acpi.h> |
| #include <linux/module.h> |
| #include <linux/idr.h> |
| #include <linux/of.h> |
| #include <linux/pwm.h> |
| #include <linux/list.h> |
| #include <linux/mutex.h> |
| #include <linux/err.h> |
| #include <linux/slab.h> |
| #include <linux/device.h> |
| #include <linux/debugfs.h> |
| #include <linux/seq_file.h> |
| |
| #include <dt-bindings/pwm/pwm.h> |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/pwm.h> |
| |
| /* protects access to pwm_chips */ |
| static DEFINE_MUTEX(pwm_lock); |
| |
| static DEFINE_IDR(pwm_chips); |
| |
| static void pwm_apply_debug(struct pwm_device *pwm, |
| const struct pwm_state *state) |
| { |
| struct pwm_state *last = &pwm->last; |
| struct pwm_chip *chip = pwm->chip; |
| struct pwm_state s1 = { 0 }, s2 = { 0 }; |
| int err; |
| |
| if (!IS_ENABLED(CONFIG_PWM_DEBUG)) |
| return; |
| |
| /* No reasonable diagnosis possible without .get_state() */ |
| if (!chip->ops->get_state) |
| return; |
| |
| /* |
| * *state was just applied. Read out the hardware state and do some |
| * checks. |
| */ |
| |
| err = chip->ops->get_state(chip, pwm, &s1); |
| trace_pwm_get(pwm, &s1, err); |
| if (err) |
| /* If that failed there isn't much to debug */ |
| return; |
| |
| /* |
| * The lowlevel driver either ignored .polarity (which is a bug) or as |
| * best effort inverted .polarity and fixed .duty_cycle respectively. |
| * Undo this inversion and fixup for further tests. |
| */ |
| if (s1.enabled && s1.polarity != state->polarity) { |
| s2.polarity = state->polarity; |
| s2.duty_cycle = s1.period - s1.duty_cycle; |
| s2.period = s1.period; |
| s2.enabled = s1.enabled; |
| } else { |
| s2 = s1; |
| } |
| |
| if (s2.polarity != state->polarity && |
| state->duty_cycle < state->period) |
| dev_warn(pwmchip_parent(chip), ".apply ignored .polarity\n"); |
| |
| if (state->enabled && |
| last->polarity == state->polarity && |
| last->period > s2.period && |
| last->period <= state->period) |
| dev_warn(pwmchip_parent(chip), |
| ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n", |
| state->period, s2.period, last->period); |
| |
| if (state->enabled && state->period < s2.period) |
| dev_warn(pwmchip_parent(chip), |
| ".apply is supposed to round down period (requested: %llu, applied: %llu)\n", |
| state->period, s2.period); |
| |
| if (state->enabled && |
| last->polarity == state->polarity && |
| last->period == s2.period && |
| last->duty_cycle > s2.duty_cycle && |
| last->duty_cycle <= state->duty_cycle) |
| dev_warn(pwmchip_parent(chip), |
| ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n", |
| state->duty_cycle, state->period, |
| s2.duty_cycle, s2.period, |
| last->duty_cycle, last->period); |
| |
| if (state->enabled && state->duty_cycle < s2.duty_cycle) |
| dev_warn(pwmchip_parent(chip), |
| ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n", |
| state->duty_cycle, state->period, |
| s2.duty_cycle, s2.period); |
| |
| if (!state->enabled && s2.enabled && s2.duty_cycle > 0) |
| dev_warn(pwmchip_parent(chip), |
| "requested disabled, but yielded enabled with duty > 0\n"); |
| |
| /* reapply the state that the driver reported being configured. */ |
| err = chip->ops->apply(chip, pwm, &s1); |
| trace_pwm_apply(pwm, &s1, err); |
| if (err) { |
| *last = s1; |
| dev_err(pwmchip_parent(chip), "failed to reapply current setting\n"); |
| return; |
| } |
| |
| *last = (struct pwm_state){ 0 }; |
| err = chip->ops->get_state(chip, pwm, last); |
| trace_pwm_get(pwm, last, err); |
| if (err) |
| return; |
| |
| /* reapplication of the current state should give an exact match */ |
| if (s1.enabled != last->enabled || |
| s1.polarity != last->polarity || |
| (s1.enabled && s1.period != last->period) || |
| (s1.enabled && s1.duty_cycle != last->duty_cycle)) { |
| dev_err(pwmchip_parent(chip), |
| ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n", |
| s1.enabled, s1.polarity, s1.duty_cycle, s1.period, |
| last->enabled, last->polarity, last->duty_cycle, |
| last->period); |
| } |
| } |
| |
| /** |
| * __pwm_apply() - atomically apply a new state to a PWM device |
| * @pwm: PWM device |
| * @state: new state to apply |
| */ |
| static int __pwm_apply(struct pwm_device *pwm, const struct pwm_state *state) |
| { |
| struct pwm_chip *chip; |
| int err; |
| |
| if (!pwm || !state || !state->period || |
| state->duty_cycle > state->period) |
| return -EINVAL; |
| |
| chip = pwm->chip; |
| |
| if (state->period == pwm->state.period && |
| state->duty_cycle == pwm->state.duty_cycle && |
| state->polarity == pwm->state.polarity && |
| state->enabled == pwm->state.enabled && |
| state->usage_power == pwm->state.usage_power) |
| return 0; |
| |
| err = chip->ops->apply(chip, pwm, state); |
| trace_pwm_apply(pwm, state, err); |
| if (err) |
| return err; |
| |
| pwm->state = *state; |
| |
| /* |
| * only do this after pwm->state was applied as some |
| * implementations of .get_state depend on this |
| */ |
| pwm_apply_debug(pwm, state); |
| |
| return 0; |
| } |
| |
| /** |
| * pwm_apply_might_sleep() - atomically apply a new state to a PWM device |
| * Cannot be used in atomic context. |
| * @pwm: PWM device |
| * @state: new state to apply |
| */ |
| int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state) |
| { |
| int err; |
| |
| /* |
| * Some lowlevel driver's implementations of .apply() make use of |
| * mutexes, also with some drivers only returning when the new |
| * configuration is active calling pwm_apply_might_sleep() from atomic context |
| * is a bad idea. So make it explicit that calling this function might |
| * sleep. |
| */ |
| might_sleep(); |
| |
| if (IS_ENABLED(CONFIG_PWM_DEBUG) && pwm->chip->atomic) { |
| /* |
| * Catch any drivers that have been marked as atomic but |
| * that will sleep anyway. |
| */ |
| non_block_start(); |
| err = __pwm_apply(pwm, state); |
| non_block_end(); |
| } else { |
| err = __pwm_apply(pwm, state); |
| } |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(pwm_apply_might_sleep); |
| |
| /** |
| * pwm_apply_atomic() - apply a new state to a PWM device from atomic context |
| * Not all PWM devices support this function, check with pwm_might_sleep(). |
| * @pwm: PWM device |
| * @state: new state to apply |
| */ |
| int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state) |
| { |
| WARN_ONCE(!pwm->chip->atomic, |
| "sleeping PWM driver used in atomic context\n"); |
| |
| return __pwm_apply(pwm, state); |
| } |
| EXPORT_SYMBOL_GPL(pwm_apply_atomic); |
| |
| /** |
| * pwm_adjust_config() - adjust the current PWM config to the PWM arguments |
| * @pwm: PWM device |
| * |
| * This function will adjust the PWM config to the PWM arguments provided |
| * by the DT or PWM lookup table. This is particularly useful to adapt |
| * the bootloader config to the Linux one. |
| */ |
| int pwm_adjust_config(struct pwm_device *pwm) |
| { |
| struct pwm_state state; |
| struct pwm_args pargs; |
| |
| pwm_get_args(pwm, &pargs); |
| pwm_get_state(pwm, &state); |
| |
| /* |
| * If the current period is zero it means that either the PWM driver |
| * does not support initial state retrieval or the PWM has not yet |
| * been configured. |
| * |
| * In either case, we setup the new period and polarity, and assign a |
| * duty cycle of 0. |
| */ |
| if (!state.period) { |
| state.duty_cycle = 0; |
| state.period = pargs.period; |
| state.polarity = pargs.polarity; |
| |
| return pwm_apply_might_sleep(pwm, &state); |
| } |
| |
| /* |
| * Adjust the PWM duty cycle/period based on the period value provided |
| * in PWM args. |
| */ |
| if (pargs.period != state.period) { |
| u64 dutycycle = (u64)state.duty_cycle * pargs.period; |
| |
| do_div(dutycycle, state.period); |
| state.duty_cycle = dutycycle; |
| state.period = pargs.period; |
| } |
| |
| /* |
| * If the polarity changed, we should also change the duty cycle. |
| */ |
| if (pargs.polarity != state.polarity) { |
| state.polarity = pargs.polarity; |
| state.duty_cycle = state.period - state.duty_cycle; |
| } |
| |
| return pwm_apply_might_sleep(pwm, &state); |
| } |
| EXPORT_SYMBOL_GPL(pwm_adjust_config); |
| |
| /** |
| * pwm_capture() - capture and report a PWM signal |
| * @pwm: PWM device |
| * @result: structure to fill with capture result |
| * @timeout: time to wait, in milliseconds, before giving up on capture |
| * |
| * Returns: 0 on success or a negative error code on failure. |
| */ |
| int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result, |
| unsigned long timeout) |
| { |
| int err; |
| |
| if (!pwm || !pwm->chip->ops) |
| return -EINVAL; |
| |
| if (!pwm->chip->ops->capture) |
| return -ENOSYS; |
| |
| mutex_lock(&pwm_lock); |
| err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout); |
| mutex_unlock(&pwm_lock); |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(pwm_capture); |
| |
| static struct pwm_chip *pwmchip_find_by_name(const char *name) |
| { |
| struct pwm_chip *chip; |
| unsigned long id, tmp; |
| |
| if (!name) |
| return NULL; |
| |
| mutex_lock(&pwm_lock); |
| |
| idr_for_each_entry_ul(&pwm_chips, chip, tmp, id) { |
| const char *chip_name = dev_name(pwmchip_parent(chip)); |
| |
| if (chip_name && strcmp(chip_name, name) == 0) { |
| mutex_unlock(&pwm_lock); |
| return chip; |
| } |
| } |
| |
| mutex_unlock(&pwm_lock); |
| |
| return NULL; |
| } |
| |
| static int pwm_device_request(struct pwm_device *pwm, const char *label) |
| { |
| int err; |
| struct pwm_chip *chip = pwm->chip; |
| const struct pwm_ops *ops = chip->ops; |
| |
| if (test_bit(PWMF_REQUESTED, &pwm->flags)) |
| return -EBUSY; |
| |
| if (!try_module_get(chip->owner)) |
| return -ENODEV; |
| |
| if (!get_device(&chip->dev)) { |
| err = -ENODEV; |
| goto err_get_device; |
| } |
| |
| if (ops->request) { |
| err = ops->request(chip, pwm); |
| if (err) { |
| put_device(&chip->dev); |
| err_get_device: |
| module_put(chip->owner); |
| return err; |
| } |
| } |
| |
| if (ops->get_state) { |
| /* |
| * Zero-initialize state because most drivers are unaware of |
| * .usage_power. The other members of state are supposed to be |
| * set by lowlevel drivers. We still initialize the whole |
| * structure for simplicity even though this might paper over |
| * faulty implementations of .get_state(). |
| */ |
| struct pwm_state state = { 0, }; |
| |
| err = ops->get_state(chip, pwm, &state); |
| trace_pwm_get(pwm, &state, err); |
| |
| if (!err) |
| pwm->state = state; |
| |
| if (IS_ENABLED(CONFIG_PWM_DEBUG)) |
| pwm->last = pwm->state; |
| } |
| |
| set_bit(PWMF_REQUESTED, &pwm->flags); |
| pwm->label = label; |
| |
| return 0; |
| } |
| |
| /** |
| * pwm_request_from_chip() - request a PWM device relative to a PWM chip |
| * @chip: PWM chip |
| * @index: per-chip index of the PWM to request |
| * @label: a literal description string of this PWM |
| * |
| * Returns: A pointer to the PWM device at the given index of the given PWM |
| * chip. A negative error code is returned if the index is not valid for the |
| * specified PWM chip or if the PWM device cannot be requested. |
| */ |
| struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, |
| unsigned int index, |
| const char *label) |
| { |
| struct pwm_device *pwm; |
| int err; |
| |
| if (!chip || index >= chip->npwm) |
| return ERR_PTR(-EINVAL); |
| |
| mutex_lock(&pwm_lock); |
| pwm = &chip->pwms[index]; |
| |
| err = pwm_device_request(pwm, label); |
| if (err < 0) |
| pwm = ERR_PTR(err); |
| |
| mutex_unlock(&pwm_lock); |
| return pwm; |
| } |
| EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
| |
| |
| struct pwm_device * |
| of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *args) |
| { |
| struct pwm_device *pwm; |
| |
| /* period in the second cell and flags in the third cell are optional */ |
| if (args->args_count < 1) |
| return ERR_PTR(-EINVAL); |
| |
| pwm = pwm_request_from_chip(chip, args->args[0], NULL); |
| if (IS_ERR(pwm)) |
| return pwm; |
| |
| if (args->args_count > 1) |
| pwm->args.period = args->args[1]; |
| |
| pwm->args.polarity = PWM_POLARITY_NORMAL; |
| if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED) |
| pwm->args.polarity = PWM_POLARITY_INVERSED; |
| |
| return pwm; |
| } |
| EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); |
| |
| struct pwm_device * |
| of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args) |
| { |
| struct pwm_device *pwm; |
| |
| pwm = pwm_request_from_chip(chip, 0, NULL); |
| if (IS_ERR(pwm)) |
| return pwm; |
| |
| if (args->args_count > 0) |
| pwm->args.period = args->args[0]; |
| |
| pwm->args.polarity = PWM_POLARITY_NORMAL; |
| if (args->args_count > 1 && args->args[1] & PWM_POLARITY_INVERTED) |
| pwm->args.polarity = PWM_POLARITY_INVERSED; |
| |
| return pwm; |
| } |
| EXPORT_SYMBOL_GPL(of_pwm_single_xlate); |
| |
| struct pwm_export { |
| struct device pwm_dev; |
| struct pwm_device *pwm; |
| struct mutex lock; |
| struct pwm_state suspend; |
| }; |
| |
| static inline struct pwm_chip *pwmchip_from_dev(struct device *pwmchip_dev) |
| { |
| return container_of(pwmchip_dev, struct pwm_chip, dev); |
| } |
| |
| static inline struct pwm_export *pwmexport_from_dev(struct device *pwm_dev) |
| { |
| return container_of(pwm_dev, struct pwm_export, pwm_dev); |
| } |
| |
| static inline struct pwm_device *pwm_from_dev(struct device *pwm_dev) |
| { |
| struct pwm_export *export = pwmexport_from_dev(pwm_dev); |
| |
| return export->pwm; |
| } |
| |
| static ssize_t period_show(struct device *pwm_dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| const struct pwm_device *pwm = pwm_from_dev(pwm_dev); |
| struct pwm_state state; |
| |
| pwm_get_state(pwm, &state); |
| |
| return sysfs_emit(buf, "%llu\n", state.period); |
| } |
| |
| static ssize_t period_store(struct device *pwm_dev, |
| struct device_attribute *attr, |
| const char *buf, size_t size) |
| { |
| struct pwm_export *export = pwmexport_from_dev(pwm_dev); |
| struct pwm_device *pwm = export->pwm; |
| struct pwm_state state; |
| u64 val; |
| int ret; |
| |
| ret = kstrtou64(buf, 0, &val); |
| if (ret) |
| return ret; |
| |
| mutex_lock(&export->lock); |
| pwm_get_state(pwm, &state); |
| state.period = val; |
| ret = pwm_apply_might_sleep(pwm, &state); |
| mutex_unlock(&export->lock); |
| |
| return ret ? : size; |
| } |
| |
| static ssize_t duty_cycle_show(struct device *pwm_dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| const struct pwm_device *pwm = pwm_from_dev(pwm_dev); |
| struct pwm_state state; |
| |
| pwm_get_state(pwm, &state); |
| |
| return sysfs_emit(buf, "%llu\n", state.duty_cycle); |
| } |
| |
| static ssize_t duty_cycle_store(struct device *pwm_dev, |
| struct device_attribute *attr, |
| const char *buf, size_t size) |
| { |
| struct pwm_export *export = pwmexport_from_dev(pwm_dev); |
| struct pwm_device *pwm = export->pwm; |
| struct pwm_state state; |
| u64 val; |
| int ret; |
| |
| ret = kstrtou64(buf, 0, &val); |
| if (ret) |
| return ret; |
| |
| mutex_lock(&export->lock); |
| pwm_get_state(pwm, &state); |
| state.duty_cycle = val; |
| ret = pwm_apply_might_sleep(pwm, &state); |
| mutex_unlock(&export->lock); |
| |
| return ret ? : size; |
| } |
| |
| static ssize_t enable_show(struct device *pwm_dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| const struct pwm_device *pwm = pwm_from_dev(pwm_dev); |
| struct pwm_state state; |
| |
| pwm_get_state(pwm, &state); |
| |
| return sysfs_emit(buf, "%d\n", state.enabled); |
| } |
| |
| static ssize_t enable_store(struct device *pwm_dev, |
| struct device_attribute *attr, |
| const char *buf, size_t size) |
| { |
| struct pwm_export *export = pwmexport_from_dev(pwm_dev); |
| struct pwm_device *pwm = export->pwm; |
| struct pwm_state state; |
| int val, ret; |
| |
| ret = kstrtoint(buf, 0, &val); |
| if (ret) |
| return ret; |
| |
| mutex_lock(&export->lock); |
| |
| pwm_get_state(pwm, &state); |
| |
| switch (val) { |
| case 0: |
| state.enabled = false; |
| break; |
| case 1: |
| state.enabled = true; |
| break; |
| default: |
| ret = -EINVAL; |
| goto unlock; |
| } |
| |
| ret = pwm_apply_might_sleep(pwm, &state); |
| |
| unlock: |
| mutex_unlock(&export->lock); |
| return ret ? : size; |
| } |
| |
| static ssize_t polarity_show(struct device *pwm_dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| const struct pwm_device *pwm = pwm_from_dev(pwm_dev); |
| const char *polarity = "unknown"; |
| struct pwm_state state; |
| |
| pwm_get_state(pwm, &state); |
| |
| switch (state.polarity) { |
| case PWM_POLARITY_NORMAL: |
| polarity = "normal"; |
| break; |
| |
| case PWM_POLARITY_INVERSED: |
| polarity = "inversed"; |
| break; |
| } |
| |
| return sysfs_emit(buf, "%s\n", polarity); |
| } |
| |
| static ssize_t polarity_store(struct device *pwm_dev, |
| struct device_attribute *attr, |
| const char *buf, size_t size) |
| { |
| struct pwm_export *export = pwmexport_from_dev(pwm_dev); |
| struct pwm_device *pwm = export->pwm; |
| enum pwm_polarity polarity; |
| struct pwm_state state; |
| int ret; |
| |
| if (sysfs_streq(buf, "normal")) |
| polarity = PWM_POLARITY_NORMAL; |
| else if (sysfs_streq(buf, "inversed")) |
| polarity = PWM_POLARITY_INVERSED; |
| else |
| return -EINVAL; |
| |
| mutex_lock(&export->lock); |
| pwm_get_state(pwm, &state); |
| state.polarity = polarity; |
| ret = pwm_apply_might_sleep(pwm, &state); |
| mutex_unlock(&export->lock); |
| |
| return ret ? : size; |
| } |
| |
| static ssize_t capture_show(struct device *pwm_dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct pwm_device *pwm = pwm_from_dev(pwm_dev); |
| struct pwm_capture result; |
| int ret; |
| |
| ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ)); |
| if (ret) |
| return ret; |
| |
| return sysfs_emit(buf, "%u %u\n", result.period, result.duty_cycle); |
| } |
| |
| static DEVICE_ATTR_RW(period); |
| static DEVICE_ATTR_RW(duty_cycle); |
| static DEVICE_ATTR_RW(enable); |
| static DEVICE_ATTR_RW(polarity); |
| static DEVICE_ATTR_RO(capture); |
| |
| static struct attribute *pwm_attrs[] = { |
| &dev_attr_period.attr, |
| &dev_attr_duty_cycle.attr, |
| &dev_attr_enable.attr, |
| &dev_attr_polarity.attr, |
| &dev_attr_capture.attr, |
| NULL |
| }; |
| ATTRIBUTE_GROUPS(pwm); |
| |
| static void pwm_export_release(struct device *pwm_dev) |
| { |
| struct pwm_export *export = pwmexport_from_dev(pwm_dev); |
| |
| kfree(export); |
| } |
| |
| static int pwm_export_child(struct device *pwmchip_dev, struct pwm_device *pwm) |
| { |
| struct pwm_export *export; |
| char *pwm_prop[2]; |
| int ret; |
| |
| if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags)) |
| return -EBUSY; |
| |
| export = kzalloc(sizeof(*export), GFP_KERNEL); |
| if (!export) { |
| clear_bit(PWMF_EXPORTED, &pwm->flags); |
| return -ENOMEM; |
| } |
| |
| export->pwm = pwm; |
| mutex_init(&export->lock); |
| |
| export->pwm_dev.release = pwm_export_release; |
| export->pwm_dev.parent = pwmchip_dev; |
| export->pwm_dev.devt = MKDEV(0, 0); |
| export->pwm_dev.groups = pwm_groups; |
| dev_set_name(&export->pwm_dev, "pwm%u", pwm->hwpwm); |
| |
| ret = device_register(&export->pwm_dev); |
| if (ret) { |
| clear_bit(PWMF_EXPORTED, &pwm->flags); |
| put_device(&export->pwm_dev); |
| export = NULL; |
| return ret; |
| } |
| pwm_prop[0] = kasprintf(GFP_KERNEL, "EXPORT=pwm%u", pwm->hwpwm); |
| pwm_prop[1] = NULL; |
| kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop); |
| kfree(pwm_prop[0]); |
| |
| return 0; |
| } |
| |
| static int pwm_unexport_match(struct device *pwm_dev, void *data) |
| { |
| return pwm_from_dev(pwm_dev) == data; |
| } |
| |
| static int pwm_unexport_child(struct device *pwmchip_dev, struct pwm_device *pwm) |
| { |
| struct device *pwm_dev; |
| char *pwm_prop[2]; |
| |
| if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags)) |
| return -ENODEV; |
| |
| pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match); |
| if (!pwm_dev) |
| return -ENODEV; |
| |
| pwm_prop[0] = kasprintf(GFP_KERNEL, "UNEXPORT=pwm%u", pwm->hwpwm); |
| pwm_prop[1] = NULL; |
| kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop); |
| kfree(pwm_prop[0]); |
| |
| /* for device_find_child() */ |
| put_device(pwm_dev); |
| device_unregister(pwm_dev); |
| pwm_put(pwm); |
| |
| return 0; |
| } |
| |
| static ssize_t export_store(struct device *pwmchip_dev, |
| struct device_attribute *attr, |
| const char *buf, size_t len) |
| { |
| struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); |
| struct pwm_device *pwm; |
| unsigned int hwpwm; |
| int ret; |
| |
| ret = kstrtouint(buf, 0, &hwpwm); |
| if (ret < 0) |
| return ret; |
| |
| if (hwpwm >= chip->npwm) |
| return -ENODEV; |
| |
| pwm = pwm_request_from_chip(chip, hwpwm, "sysfs"); |
| if (IS_ERR(pwm)) |
| return PTR_ERR(pwm); |
| |
| ret = pwm_export_child(pwmchip_dev, pwm); |
| if (ret < 0) |
| pwm_put(pwm); |
| |
| return ret ? : len; |
| } |
| static DEVICE_ATTR_WO(export); |
| |
| static ssize_t unexport_store(struct device *pwmchip_dev, |
| struct device_attribute *attr, |
| const char *buf, size_t len) |
| { |
| struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); |
| unsigned int hwpwm; |
| int ret; |
| |
| ret = kstrtouint(buf, 0, &hwpwm); |
| if (ret < 0) |
| return ret; |
| |
| if (hwpwm >= chip->npwm) |
| return -ENODEV; |
| |
| ret = pwm_unexport_child(pwmchip_dev, &chip->pwms[hwpwm]); |
| |
| return ret ? : len; |
| } |
| static DEVICE_ATTR_WO(unexport); |
| |
| static ssize_t npwm_show(struct device *pwmchip_dev, struct device_attribute *attr, |
| char *buf) |
| { |
| const struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); |
| |
| return sysfs_emit(buf, "%u\n", chip->npwm); |
| } |
| static DEVICE_ATTR_RO(npwm); |
| |
| static struct attribute *pwm_chip_attrs[] = { |
| &dev_attr_export.attr, |
| &dev_attr_unexport.attr, |
| &dev_attr_npwm.attr, |
| NULL, |
| }; |
| ATTRIBUTE_GROUPS(pwm_chip); |
| |
| /* takes export->lock on success */ |
| static struct pwm_export *pwm_class_get_state(struct device *pwmchip_dev, |
| struct pwm_device *pwm, |
| struct pwm_state *state) |
| { |
| struct device *pwm_dev; |
| struct pwm_export *export; |
| |
| if (!test_bit(PWMF_EXPORTED, &pwm->flags)) |
| return NULL; |
| |
| pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match); |
| if (!pwm_dev) |
| return NULL; |
| |
| export = pwmexport_from_dev(pwm_dev); |
| put_device(pwm_dev); /* for device_find_child() */ |
| |
| mutex_lock(&export->lock); |
| pwm_get_state(pwm, state); |
| |
| return export; |
| } |
| |
| static int pwm_class_apply_state(struct pwm_export *export, |
| struct pwm_device *pwm, |
| struct pwm_state *state) |
| { |
| int ret = pwm_apply_might_sleep(pwm, state); |
| |
| /* release lock taken in pwm_class_get_state */ |
| mutex_unlock(&export->lock); |
| |
| return ret; |
| } |
| |
| static int pwm_class_resume_npwm(struct device *pwmchip_dev, unsigned int npwm) |
| { |
| struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); |
| unsigned int i; |
| int ret = 0; |
| |
| for (i = 0; i < npwm; i++) { |
| struct pwm_device *pwm = &chip->pwms[i]; |
| struct pwm_state state; |
| struct pwm_export *export; |
| |
| export = pwm_class_get_state(pwmchip_dev, pwm, &state); |
| if (!export) |
| continue; |
| |
| /* If pwmchip was not enabled before suspend, do nothing. */ |
| if (!export->suspend.enabled) { |
| /* release lock taken in pwm_class_get_state */ |
| mutex_unlock(&export->lock); |
| continue; |
| } |
| |
| state.enabled = export->suspend.enabled; |
| ret = pwm_class_apply_state(export, pwm, &state); |
| if (ret < 0) |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static int pwm_class_suspend(struct device *pwmchip_dev) |
| { |
| struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); |
| unsigned int i; |
| int ret = 0; |
| |
| for (i = 0; i < chip->npwm; i++) { |
| struct pwm_device *pwm = &chip->pwms[i]; |
| struct pwm_state state; |
| struct pwm_export *export; |
| |
| export = pwm_class_get_state(pwmchip_dev, pwm, &state); |
| if (!export) |
| continue; |
| |
| /* |
| * If pwmchip was not enabled before suspend, save |
| * state for resume time and do nothing else. |
| */ |
| export->suspend = state; |
| if (!state.enabled) { |
| /* release lock taken in pwm_class_get_state */ |
| mutex_unlock(&export->lock); |
| continue; |
| } |
| |
| state.enabled = false; |
| ret = pwm_class_apply_state(export, pwm, &state); |
| if (ret < 0) { |
| /* |
| * roll back the PWM devices that were disabled by |
| * this suspend function. |
| */ |
| pwm_class_resume_npwm(pwmchip_dev, i); |
| break; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static int pwm_class_resume(struct device *pwmchip_dev) |
| { |
| struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); |
| |
| return pwm_class_resume_npwm(pwmchip_dev, chip->npwm); |
| } |
| |
| static DEFINE_SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume); |
| |
| static struct class pwm_class = { |
| .name = "pwm", |
| .dev_groups = pwm_chip_groups, |
| .pm = pm_sleep_ptr(&pwm_class_pm_ops), |
| }; |
| |
| static void pwmchip_sysfs_unexport(struct pwm_chip *chip) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < chip->npwm; i++) { |
| struct pwm_device *pwm = &chip->pwms[i]; |
| |
| if (test_bit(PWMF_EXPORTED, &pwm->flags)) |
| pwm_unexport_child(&chip->dev, pwm); |
| } |
| } |
| |
| #define PWMCHIP_ALIGN ARCH_DMA_MINALIGN |
| |
| static void *pwmchip_priv(struct pwm_chip *chip) |
| { |
| return (void *)chip + ALIGN(struct_size(chip, pwms, chip->npwm), PWMCHIP_ALIGN); |
| } |
| |
| /* This is the counterpart to pwmchip_alloc() */ |
| void pwmchip_put(struct pwm_chip *chip) |
| { |
| put_device(&chip->dev); |
| } |
| EXPORT_SYMBOL_GPL(pwmchip_put); |
| |
| static void pwmchip_release(struct device *pwmchip_dev) |
| { |
| struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); |
| |
| kfree(chip); |
| } |
| |
| struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv) |
| { |
| struct pwm_chip *chip; |
| struct device *pwmchip_dev; |
| size_t alloc_size; |
| unsigned int i; |
| |
| alloc_size = size_add(ALIGN(struct_size(chip, pwms, npwm), PWMCHIP_ALIGN), |
| sizeof_priv); |
| |
| chip = kzalloc(alloc_size, GFP_KERNEL); |
| if (!chip) |
| return ERR_PTR(-ENOMEM); |
| |
| chip->npwm = npwm; |
| chip->uses_pwmchip_alloc = true; |
| |
| pwmchip_dev = &chip->dev; |
| device_initialize(pwmchip_dev); |
| pwmchip_dev->class = &pwm_class; |
| pwmchip_dev->parent = parent; |
| pwmchip_dev->release = pwmchip_release; |
| |
| pwmchip_set_drvdata(chip, pwmchip_priv(chip)); |
| |
| for (i = 0; i < chip->npwm; i++) { |
| struct pwm_device *pwm = &chip->pwms[i]; |
| pwm->chip = chip; |
| pwm->hwpwm = i; |
| } |
| |
| return chip; |
| } |
| EXPORT_SYMBOL_GPL(pwmchip_alloc); |
| |
| static void devm_pwmchip_put(void *data) |
| { |
| struct pwm_chip *chip = data; |
| |
| pwmchip_put(chip); |
| } |
| |
| struct pwm_chip *devm_pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv) |
| { |
| struct pwm_chip *chip; |
| int ret; |
| |
| chip = pwmchip_alloc(parent, npwm, sizeof_priv); |
| if (IS_ERR(chip)) |
| return chip; |
| |
| ret = devm_add_action_or_reset(parent, devm_pwmchip_put, chip); |
| if (ret) |
| return ERR_PTR(ret); |
| |
| return chip; |
| } |
| EXPORT_SYMBOL_GPL(devm_pwmchip_alloc); |
| |
| static void of_pwmchip_add(struct pwm_chip *chip) |
| { |
| if (!pwmchip_parent(chip) || !pwmchip_parent(chip)->of_node) |
| return; |
| |
| if (!chip->of_xlate) |
| chip->of_xlate = of_pwm_xlate_with_flags; |
| |
| of_node_get(pwmchip_parent(chip)->of_node); |
| } |
| |
| static void of_pwmchip_remove(struct pwm_chip *chip) |
| { |
| if (pwmchip_parent(chip)) |
| of_node_put(pwmchip_parent(chip)->of_node); |
| } |
| |
| static bool pwm_ops_check(const struct pwm_chip *chip) |
| { |
| const struct pwm_ops *ops = chip->ops; |
| |
| if (!ops->apply) |
| return false; |
| |
| if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state) |
| dev_warn(pwmchip_parent(chip), |
| "Please implement the .get_state() callback\n"); |
| |
| return true; |
| } |
| |
| /** |
| * __pwmchip_add() - register a new PWM chip |
| * @chip: the PWM chip to add |
| * @owner: reference to the module providing the chip. |
| * |
| * Register a new PWM chip. @owner is supposed to be THIS_MODULE, use the |
| * pwmchip_add wrapper to do this right. |
| * |
| * Returns: 0 on success or a negative error code on failure. |
| */ |
| int __pwmchip_add(struct pwm_chip *chip, struct module *owner) |
| { |
| int ret; |
| |
| if (!chip || !pwmchip_parent(chip) || !chip->ops || !chip->npwm) |
| return -EINVAL; |
| |
| /* |
| * a struct pwm_chip must be allocated using (devm_)pwmchip_alloc, |
| * otherwise the embedded struct device might disappear too early |
| * resulting in memory corruption. |
| * Catch drivers that were not converted appropriately. |
| */ |
| if (!chip->uses_pwmchip_alloc) |
| return -EINVAL; |
| |
| if (!pwm_ops_check(chip)) |
| return -EINVAL; |
| |
| chip->owner = owner; |
| |
| mutex_lock(&pwm_lock); |
| |
| ret = idr_alloc(&pwm_chips, chip, 0, 0, GFP_KERNEL); |
| if (ret < 0) |
| goto err_idr_alloc; |
| |
| chip->id = ret; |
| |
| dev_set_name(&chip->dev, "pwmchip%u", chip->id); |
| |
| if (IS_ENABLED(CONFIG_OF)) |
| of_pwmchip_add(chip); |
| |
| ret = device_add(&chip->dev); |
| if (ret) |
| goto err_device_add; |
| |
| mutex_unlock(&pwm_lock); |
| |
| return 0; |
| |
| err_device_add: |
| if (IS_ENABLED(CONFIG_OF)) |
| of_pwmchip_remove(chip); |
| |
| idr_remove(&pwm_chips, chip->id); |
| err_idr_alloc: |
| |
| mutex_unlock(&pwm_lock); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(__pwmchip_add); |
| |
| /** |
| * pwmchip_remove() - remove a PWM chip |
| * @chip: the PWM chip to remove |
| * |
| * Removes a PWM chip. |
| */ |
| void pwmchip_remove(struct pwm_chip *chip) |
| { |
| pwmchip_sysfs_unexport(chip); |
| |
| if (IS_ENABLED(CONFIG_OF)) |
| of_pwmchip_remove(chip); |
| |
| mutex_lock(&pwm_lock); |
| |
| idr_remove(&pwm_chips, chip->id); |
| |
| mutex_unlock(&pwm_lock); |
| |
| device_del(&chip->dev); |
| } |
| EXPORT_SYMBOL_GPL(pwmchip_remove); |
| |
| static void devm_pwmchip_remove(void *data) |
| { |
| struct pwm_chip *chip = data; |
| |
| pwmchip_remove(chip); |
| } |
| |
| int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner) |
| { |
| int ret; |
| |
| ret = __pwmchip_add(chip, owner); |
| if (ret) |
| return ret; |
| |
| return devm_add_action_or_reset(dev, devm_pwmchip_remove, chip); |
| } |
| EXPORT_SYMBOL_GPL(__devm_pwmchip_add); |
| |
| static struct device_link *pwm_device_link_add(struct device *dev, |
| struct pwm_device *pwm) |
| { |
| struct device_link *dl; |
| |
| if (!dev) { |
| /* |
| * No device for the PWM consumer has been provided. It may |
| * impact the PM sequence ordering: the PWM supplier may get |
| * suspended before the consumer. |
| */ |
| dev_warn(pwmchip_parent(pwm->chip), |
| "No consumer device specified to create a link to\n"); |
| return NULL; |
| } |
| |
| dl = device_link_add(dev, pwmchip_parent(pwm->chip), DL_FLAG_AUTOREMOVE_CONSUMER); |
| if (!dl) { |
| dev_err(dev, "failed to create device link to %s\n", |
| dev_name(pwmchip_parent(pwm->chip))); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| return dl; |
| } |
| |
| static struct pwm_chip *fwnode_to_pwmchip(struct fwnode_handle *fwnode) |
| { |
| struct pwm_chip *chip; |
| unsigned long id, tmp; |
| |
| mutex_lock(&pwm_lock); |
| |
| idr_for_each_entry_ul(&pwm_chips, chip, tmp, id) |
| if (pwmchip_parent(chip) && device_match_fwnode(pwmchip_parent(chip), fwnode)) { |
| mutex_unlock(&pwm_lock); |
| return chip; |
| } |
| |
| mutex_unlock(&pwm_lock); |
| |
| return ERR_PTR(-EPROBE_DEFER); |
| } |
| |
| /** |
| * of_pwm_get() - request a PWM via the PWM framework |
| * @dev: device for PWM consumer |
| * @np: device node to get the PWM from |
| * @con_id: consumer name |
| * |
| * Returns the PWM device parsed from the phandle and index specified in the |
| * "pwms" property of a device tree node or a negative error-code on failure. |
| * Values parsed from the device tree are stored in the returned PWM device |
| * object. |
| * |
| * If con_id is NULL, the first PWM device listed in the "pwms" property will |
| * be requested. Otherwise the "pwm-names" property is used to do a reverse |
| * lookup of the PWM index. This also means that the "pwm-names" property |
| * becomes mandatory for devices that look up the PWM device via the con_id |
| * parameter. |
| * |
| * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded |
| * error code on failure. |
| */ |
| static struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np, |
| const char *con_id) |
| { |
| struct pwm_device *pwm = NULL; |
| struct of_phandle_args args; |
| struct device_link *dl; |
| struct pwm_chip *chip; |
| int index = 0; |
| int err; |
| |
| if (con_id) { |
| index = of_property_match_string(np, "pwm-names", con_id); |
| if (index < 0) |
| return ERR_PTR(index); |
| } |
| |
| err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, |
| &args); |
| if (err) { |
| pr_err("%s(): can't parse \"pwms\" property\n", __func__); |
| return ERR_PTR(err); |
| } |
| |
| chip = fwnode_to_pwmchip(of_fwnode_handle(args.np)); |
| if (IS_ERR(chip)) { |
| if (PTR_ERR(chip) != -EPROBE_DEFER) |
| pr_err("%s(): PWM chip not found\n", __func__); |
| |
| pwm = ERR_CAST(chip); |
| goto put; |
| } |
| |
| pwm = chip->of_xlate(chip, &args); |
| if (IS_ERR(pwm)) |
| goto put; |
| |
| dl = pwm_device_link_add(dev, pwm); |
| if (IS_ERR(dl)) { |
| /* of_xlate ended up calling pwm_request_from_chip() */ |
| pwm_put(pwm); |
| pwm = ERR_CAST(dl); |
| goto put; |
| } |
| |
| /* |
| * If a consumer name was not given, try to look it up from the |
| * "pwm-names" property if it exists. Otherwise use the name of |
| * the user device node. |
| */ |
| if (!con_id) { |
| err = of_property_read_string_index(np, "pwm-names", index, |
| &con_id); |
| if (err < 0) |
| con_id = np->name; |
| } |
| |
| pwm->label = con_id; |
| |
| put: |
| of_node_put(args.np); |
| |
| return pwm; |
| } |
| |
| /** |
| * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI |
| * @fwnode: firmware node to get the "pwms" property from |
| * |
| * Returns the PWM device parsed from the fwnode and index specified in the |
| * "pwms" property or a negative error-code on failure. |
| * Values parsed from the device tree are stored in the returned PWM device |
| * object. |
| * |
| * This is analogous to of_pwm_get() except con_id is not yet supported. |
| * ACPI entries must look like |
| * Package () {"pwms", Package () |
| * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}} |
| * |
| * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded |
| * error code on failure. |
| */ |
| static struct pwm_device *acpi_pwm_get(const struct fwnode_handle *fwnode) |
| { |
| struct pwm_device *pwm; |
| struct fwnode_reference_args args; |
| struct pwm_chip *chip; |
| int ret; |
| |
| memset(&args, 0, sizeof(args)); |
| |
| ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args); |
| if (ret < 0) |
| return ERR_PTR(ret); |
| |
| if (args.nargs < 2) |
| return ERR_PTR(-EPROTO); |
| |
| chip = fwnode_to_pwmchip(args.fwnode); |
| if (IS_ERR(chip)) |
| return ERR_CAST(chip); |
| |
| pwm = pwm_request_from_chip(chip, args.args[0], NULL); |
| if (IS_ERR(pwm)) |
| return pwm; |
| |
| pwm->args.period = args.args[1]; |
| pwm->args.polarity = PWM_POLARITY_NORMAL; |
| |
| if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED) |
| pwm->args.polarity = PWM_POLARITY_INVERSED; |
| |
| return pwm; |
| } |
| |
| static DEFINE_MUTEX(pwm_lookup_lock); |
| static LIST_HEAD(pwm_lookup_list); |
| |
| /** |
| * pwm_add_table() - register PWM device consumers |
| * @table: array of consumers to register |
| * @num: number of consumers in table |
| */ |
| void pwm_add_table(struct pwm_lookup *table, size_t num) |
| { |
| mutex_lock(&pwm_lookup_lock); |
| |
| while (num--) { |
| list_add_tail(&table->list, &pwm_lookup_list); |
| table++; |
| } |
| |
| mutex_unlock(&pwm_lookup_lock); |
| } |
| |
| /** |
| * pwm_remove_table() - unregister PWM device consumers |
| * @table: array of consumers to unregister |
| * @num: number of consumers in table |
| */ |
| void pwm_remove_table(struct pwm_lookup *table, size_t num) |
| { |
| mutex_lock(&pwm_lookup_lock); |
| |
| while (num--) { |
| list_del(&table->list); |
| table++; |
| } |
| |
| mutex_unlock(&pwm_lookup_lock); |
| } |
| |
| /** |
| * pwm_get() - look up and request a PWM device |
| * @dev: device for PWM consumer |
| * @con_id: consumer name |
| * |
| * Lookup is first attempted using DT. If the device was not instantiated from |
| * a device tree, a PWM chip and a relative index is looked up via a table |
| * supplied by board setup code (see pwm_add_table()). |
| * |
| * Once a PWM chip has been found the specified PWM device will be requested |
| * and is ready to be used. |
| * |
| * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded |
| * error code on failure. |
| */ |
| struct pwm_device *pwm_get(struct device *dev, const char *con_id) |
| { |
| const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL; |
| const char *dev_id = dev ? dev_name(dev) : NULL; |
| struct pwm_device *pwm; |
| struct pwm_chip *chip; |
| struct device_link *dl; |
| unsigned int best = 0; |
| struct pwm_lookup *p, *chosen = NULL; |
| unsigned int match; |
| int err; |
| |
| /* look up via DT first */ |
| if (is_of_node(fwnode)) |
| return of_pwm_get(dev, to_of_node(fwnode), con_id); |
| |
| /* then lookup via ACPI */ |
| if (is_acpi_node(fwnode)) { |
| pwm = acpi_pwm_get(fwnode); |
| if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT) |
| return pwm; |
| } |
| |
| /* |
| * We look up the provider in the static table typically provided by |
| * board setup code. We first try to lookup the consumer device by |
| * name. If the consumer device was passed in as NULL or if no match |
| * was found, we try to find the consumer by directly looking it up |
| * by name. |
| * |
| * If a match is found, the provider PWM chip is looked up by name |
| * and a PWM device is requested using the PWM device per-chip index. |
| * |
| * The lookup algorithm was shamelessly taken from the clock |
| * framework: |
| * |
| * We do slightly fuzzy matching here: |
| * An entry with a NULL ID is assumed to be a wildcard. |
| * If an entry has a device ID, it must match |
| * If an entry has a connection ID, it must match |
| * Then we take the most specific entry - with the following order |
| * of precedence: dev+con > dev only > con only. |
| */ |
| mutex_lock(&pwm_lookup_lock); |
| |
| list_for_each_entry(p, &pwm_lookup_list, list) { |
| match = 0; |
| |
| if (p->dev_id) { |
| if (!dev_id || strcmp(p->dev_id, dev_id)) |
| continue; |
| |
| match += 2; |
| } |
| |
| if (p->con_id) { |
| if (!con_id || strcmp(p->con_id, con_id)) |
| continue; |
| |
| match += 1; |
| } |
| |
| if (match > best) { |
| chosen = p; |
| |
| if (match != 3) |
| best = match; |
| else |
| break; |
| } |
| } |
| |
| mutex_unlock(&pwm_lookup_lock); |
| |
| if (!chosen) |
| return ERR_PTR(-ENODEV); |
| |
| chip = pwmchip_find_by_name(chosen->provider); |
| |
| /* |
| * If the lookup entry specifies a module, load the module and retry |
| * the PWM chip lookup. This can be used to work around driver load |
| * ordering issues if driver's can't be made to properly support the |
| * deferred probe mechanism. |
| */ |
| if (!chip && chosen->module) { |
| err = request_module(chosen->module); |
| if (err == 0) |
| chip = pwmchip_find_by_name(chosen->provider); |
| } |
| |
| if (!chip) |
| return ERR_PTR(-EPROBE_DEFER); |
| |
| pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id); |
| if (IS_ERR(pwm)) |
| return pwm; |
| |
| dl = pwm_device_link_add(dev, pwm); |
| if (IS_ERR(dl)) { |
| pwm_put(pwm); |
| return ERR_CAST(dl); |
| } |
| |
| pwm->args.period = chosen->period; |
| pwm->args.polarity = chosen->polarity; |
| |
| return pwm; |
| } |
| EXPORT_SYMBOL_GPL(pwm_get); |
| |
| /** |
| * pwm_put() - release a PWM device |
| * @pwm: PWM device |
| */ |
| void pwm_put(struct pwm_device *pwm) |
| { |
| struct pwm_chip *chip; |
| |
| if (!pwm) |
| return; |
| |
| chip = pwm->chip; |
| |
| mutex_lock(&pwm_lock); |
| |
| if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { |
| pr_warn("PWM device already freed\n"); |
| goto out; |
| } |
| |
| if (chip->ops->free) |
| pwm->chip->ops->free(pwm->chip, pwm); |
| |
| pwm->label = NULL; |
| |
| put_device(&chip->dev); |
| |
| module_put(chip->owner); |
| out: |
| mutex_unlock(&pwm_lock); |
| } |
| EXPORT_SYMBOL_GPL(pwm_put); |
| |
| static void devm_pwm_release(void *pwm) |
| { |
| pwm_put(pwm); |
| } |
| |
| /** |
| * devm_pwm_get() - resource managed pwm_get() |
| * @dev: device for PWM consumer |
| * @con_id: consumer name |
| * |
| * This function performs like pwm_get() but the acquired PWM device will |
| * automatically be released on driver detach. |
| * |
| * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded |
| * error code on failure. |
| */ |
| struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) |
| { |
| struct pwm_device *pwm; |
| int ret; |
| |
| pwm = pwm_get(dev, con_id); |
| if (IS_ERR(pwm)) |
| return pwm; |
| |
| ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm); |
| if (ret) |
| return ERR_PTR(ret); |
| |
| return pwm; |
| } |
| EXPORT_SYMBOL_GPL(devm_pwm_get); |
| |
| /** |
| * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node |
| * @dev: device for PWM consumer |
| * @fwnode: firmware node to get the PWM from |
| * @con_id: consumer name |
| * |
| * Returns the PWM device parsed from the firmware node. See of_pwm_get() and |
| * acpi_pwm_get() for a detailed description. |
| * |
| * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded |
| * error code on failure. |
| */ |
| struct pwm_device *devm_fwnode_pwm_get(struct device *dev, |
| struct fwnode_handle *fwnode, |
| const char *con_id) |
| { |
| struct pwm_device *pwm = ERR_PTR(-ENODEV); |
| int ret; |
| |
| if (is_of_node(fwnode)) |
| pwm = of_pwm_get(dev, to_of_node(fwnode), con_id); |
| else if (is_acpi_node(fwnode)) |
| pwm = acpi_pwm_get(fwnode); |
| if (IS_ERR(pwm)) |
| return pwm; |
| |
| ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm); |
| if (ret) |
| return ERR_PTR(ret); |
| |
| return pwm; |
| } |
| EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get); |
| |
| static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < chip->npwm; i++) { |
| struct pwm_device *pwm = &chip->pwms[i]; |
| struct pwm_state state; |
| |
| pwm_get_state(pwm, &state); |
| |
| seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); |
| |
| if (test_bit(PWMF_REQUESTED, &pwm->flags)) |
| seq_puts(s, " requested"); |
| |
| if (state.enabled) |
| seq_puts(s, " enabled"); |
| |
| seq_printf(s, " period: %llu ns", state.period); |
| seq_printf(s, " duty: %llu ns", state.duty_cycle); |
| seq_printf(s, " polarity: %s", |
| state.polarity ? "inverse" : "normal"); |
| |
| if (state.usage_power) |
| seq_puts(s, " usage_power"); |
| |
| seq_puts(s, "\n"); |
| } |
| } |
| |
| static void *pwm_seq_start(struct seq_file *s, loff_t *pos) |
| { |
| unsigned long id = *pos; |
| void *ret; |
| |
| mutex_lock(&pwm_lock); |
| s->private = ""; |
| |
| ret = idr_get_next_ul(&pwm_chips, &id); |
| *pos = id; |
| return ret; |
| } |
| |
| static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) |
| { |
| unsigned long id = *pos + 1; |
| void *ret; |
| |
| s->private = "\n"; |
| |
| ret = idr_get_next_ul(&pwm_chips, &id); |
| *pos = id; |
| return ret; |
| } |
| |
| static void pwm_seq_stop(struct seq_file *s, void *v) |
| { |
| mutex_unlock(&pwm_lock); |
| } |
| |
| static int pwm_seq_show(struct seq_file *s, void *v) |
| { |
| struct pwm_chip *chip = v; |
| |
| seq_printf(s, "%s%d: %s/%s, %d PWM device%s\n", |
| (char *)s->private, chip->id, |
| pwmchip_parent(chip)->bus ? pwmchip_parent(chip)->bus->name : "no-bus", |
| dev_name(pwmchip_parent(chip)), chip->npwm, |
| (chip->npwm != 1) ? "s" : ""); |
| |
| pwm_dbg_show(chip, s); |
| |
| return 0; |
| } |
| |
| static const struct seq_operations pwm_debugfs_sops = { |
| .start = pwm_seq_start, |
| .next = pwm_seq_next, |
| .stop = pwm_seq_stop, |
| .show = pwm_seq_show, |
| }; |
| |
| DEFINE_SEQ_ATTRIBUTE(pwm_debugfs); |
| |
| static int __init pwm_init(void) |
| { |
| if (IS_ENABLED(CONFIG_DEBUG_FS)) |
| debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops); |
| |
| return class_register(&pwm_class); |
| } |
| subsys_initcall(pwm_init); |