diff options
Diffstat (limited to 'drivers/pwm/core.c')
| -rw-r--r-- | drivers/pwm/core.c | 619 |
1 files changed, 310 insertions, 309 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index b025d90e201c..1b4c3d0caa82 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -24,289 +24,11 @@ #define CREATE_TRACE_POINTS #include <trace/events/pwm.h> -static DEFINE_MUTEX(pwm_lookup_lock); -static LIST_HEAD(pwm_lookup_list); - /* protects access to pwm_chips */ static DEFINE_MUTEX(pwm_lock); static DEFINE_IDR(pwm_chips); -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(chip->dev); - - 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 (ops->request) { - err = ops->request(chip, pwm); - if (err) { - 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; -} - -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 > 1) - 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); - -static void of_pwmchip_add(struct pwm_chip *chip) -{ - if (!chip->dev || !chip->dev->of_node) - return; - - if (!chip->of_xlate) - chip->of_xlate = of_pwm_xlate_with_flags; - - of_node_get(chip->dev->of_node); -} - -static void of_pwmchip_remove(struct pwm_chip *chip) -{ - if (chip->dev) - of_node_put(chip->dev->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(chip->dev, - "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) -{ - unsigned int i; - int ret; - - if (!chip || !chip->dev || !chip->ops || !chip->npwm) - return -EINVAL; - - if (!pwm_ops_check(chip)) - return -EINVAL; - - chip->owner = owner; - - chip->pwms = kcalloc(chip->npwm, sizeof(*chip->pwms), GFP_KERNEL); - if (!chip->pwms) - return -ENOMEM; - - mutex_lock(&pwm_lock); - - ret = idr_alloc(&pwm_chips, chip, 0, 0, GFP_KERNEL); - if (ret < 0) { - mutex_unlock(&pwm_lock); - kfree(chip->pwms); - return ret; - } - - chip->id = ret; - - for (i = 0; i < chip->npwm; i++) { - struct pwm_device *pwm = &chip->pwms[i]; - - pwm->chip = chip; - pwm->hwpwm = i; - } - - mutex_unlock(&pwm_lock); - - if (IS_ENABLED(CONFIG_OF)) - of_pwmchip_add(chip); - - pwmchip_sysfs_export(chip); - - return 0; -} -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); - - kfree(chip->pwms); -} -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); - -/** - * 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); - static void pwm_apply_debug(struct pwm_device *pwm, const struct pwm_state *state) { @@ -503,33 +225,6 @@ int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state) EXPORT_SYMBOL_GPL(pwm_apply_atomic); /** - * 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); - -/** * pwm_adjust_config() - adjust the current PWM config to the PWM arguments * @pwm: PWM device * @@ -585,24 +280,309 @@ int pwm_adjust_config(struct pwm_device *pwm) } EXPORT_SYMBOL_GPL(pwm_adjust_config); -static struct pwm_chip *fwnode_to_pwmchip(struct fwnode_handle *fwnode) +/** + * 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) - if (chip->dev && device_match_fwnode(chip->dev, fwnode)) { + idr_for_each_entry_ul(&pwm_chips, chip, tmp, id) { + const char *chip_name = dev_name(chip->dev); + + if (chip_name && strcmp(chip_name, name) == 0) { mutex_unlock(&pwm_lock); return chip; } + } mutex_unlock(&pwm_lock); - return ERR_PTR(-EPROBE_DEFER); + 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 (ops->request) { + err = ops->request(chip, pwm); + if (err) { + 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 > 1) + 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); + +static void of_pwmchip_add(struct pwm_chip *chip) +{ + if (!chip->dev || !chip->dev->of_node) + return; + + if (!chip->of_xlate) + chip->of_xlate = of_pwm_xlate_with_flags; + + of_node_get(chip->dev->of_node); +} + +static void of_pwmchip_remove(struct pwm_chip *chip) +{ + if (chip->dev) + of_node_put(chip->dev->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(chip->dev, + "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) +{ + unsigned int i; + int ret; + + if (!chip || !chip->dev || !chip->ops || !chip->npwm) + return -EINVAL; + + if (!pwm_ops_check(chip)) + return -EINVAL; + + chip->owner = owner; + + chip->pwms = kcalloc(chip->npwm, sizeof(*chip->pwms), GFP_KERNEL); + if (!chip->pwms) + return -ENOMEM; + + mutex_lock(&pwm_lock); + + ret = idr_alloc(&pwm_chips, chip, 0, 0, GFP_KERNEL); + if (ret < 0) { + mutex_unlock(&pwm_lock); + kfree(chip->pwms); + return ret; + } + + chip->id = ret; + + for (i = 0; i < chip->npwm; i++) { + struct pwm_device *pwm = &chip->pwms[i]; + + pwm->chip = chip; + pwm->hwpwm = i; + } + + mutex_unlock(&pwm_lock); + + if (IS_ENABLED(CONFIG_OF)) + of_pwmchip_add(chip); + + pwmchip_sysfs_export(chip); + + return 0; +} +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); + + kfree(chip->pwms); +} +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) { @@ -629,6 +609,24 @@ static struct device_link *pwm_device_link_add(struct device *dev, 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 (chip->dev && device_match_fwnode(chip->dev, 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 @@ -763,6 +761,9 @@ static struct pwm_device *acpi_pwm_get(const struct fwnode_handle *fwnode) 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 |