diff options
| -rw-r--r-- | Documentation/driver-model/devres.txt | 4 | ||||
| -rw-r--r-- | Documentation/pwm.txt | 3 | ||||
| -rw-r--r-- | drivers/pwm/core.c | 58 | ||||
| -rw-r--r-- | include/linux/pwm.h | 3 |
4 files changed, 67 insertions, 1 deletions
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index 950856bd2e3..43cff70465a 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -284,3 +284,7 @@ CLOCK PINCTRL devm_pinctrl_get() devm_pinctrl_put() + +PWM + devm_pwm_get() + devm_pwm_put() diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt index 554290ebab9..7d2b4c9b544 100644 --- a/Documentation/pwm.txt +++ b/Documentation/pwm.txt @@ -36,7 +36,8 @@ Legacy users can request a PWM device using pwm_request() and free it after usage with pwm_free(). New users should use the pwm_get() function and pass to it the consumer -device or a consumer name. pwm_put() is used to free the PWM device. +device or a consumer name. pwm_put() is used to free the PWM device. Managed +variants of these functions, devm_pwm_get() and devm_pwm_put(), also exist. After being requested a PWM has to be configured using: diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 85592e97ef2..92b1782d0d8 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -646,6 +646,64 @@ out: } EXPORT_SYMBOL_GPL(pwm_put); +static void devm_pwm_release(struct device *dev, void *res) +{ + pwm_put(*(struct pwm_device **)res); +} + +/** + * 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. + */ +struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) +{ + struct pwm_device **ptr, *pwm; + + ptr = devres_alloc(devm_pwm_release, sizeof(**ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + pwm = pwm_get(dev, con_id); + if (!IS_ERR(pwm)) { + *ptr = pwm; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return pwm; +} +EXPORT_SYMBOL_GPL(devm_pwm_get); + +static int devm_pwm_match(struct device *dev, void *res, void *data) +{ + struct pwm_device **p = res; + + if (WARN_ON(!p || !*p)) + return 0; + + return *p == data; +} + +/** + * devm_pwm_put() - resource managed pwm_put() + * @dev: device for PWM consumer + * @pwm: PWM device + * + * Release a PWM previously allocated using devm_pwm_get(). Calling this + * function is usually not needed because devm-allocated resources are + * automatically released on driver detach. + */ +void devm_pwm_put(struct device *dev, struct pwm_device *pwm) +{ + WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm)); +} +EXPORT_SYMBOL_GPL(devm_pwm_put); + #ifdef CONFIG_DEBUG_FS static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) { diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 354764cf5f7..40c76431895 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -148,6 +148,9 @@ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, struct pwm_device *pwm_get(struct device *dev, const char *consumer); void pwm_put(struct pwm_device *pwm); +struct pwm_device *devm_pwm_get(struct device *dev, const char *consumer); +void devm_pwm_put(struct device *dev, struct pwm_device *pwm); + struct pwm_lookup { struct list_head list; const char *provider; |