diff options
| -rw-r--r-- | Documentation/driver-api/driver-model/devres.rst | 1 | ||||
| -rw-r--r-- | Documentation/driver-api/pwm.rst | 11 | ||||
| -rw-r--r-- | drivers/pwm/core.c | 58 | ||||
| -rw-r--r-- | include/linux/pwm.h | 22 |
4 files changed, 87 insertions, 5 deletions
diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst index c5f99d834ec5..e4df72c408d2 100644 --- a/Documentation/driver-api/driver-model/devres.rst +++ b/Documentation/driver-api/driver-model/devres.rst @@ -420,6 +420,7 @@ POWER devm_reboot_mode_unregister() PWM + devm_pwmchip_alloc() devm_pwmchip_add() devm_pwm_get() devm_fwnode_pwm_get() diff --git a/Documentation/driver-api/pwm.rst b/Documentation/driver-api/pwm.rst index 3c28ccc4b611..b41b1c56477f 100644 --- a/Documentation/driver-api/pwm.rst +++ b/Documentation/driver-api/pwm.rst @@ -143,11 +143,12 @@ to implement the pwm_*() functions itself. This means that it's impossible to have multiple PWM drivers in the system. For this reason it's mandatory for new drivers to use the generic PWM framework. -A new PWM controller/chip can be added using pwmchip_add() and removed -again with pwmchip_remove(). pwmchip_add() takes a filled in struct -pwm_chip as argument which provides a description of the PWM chip, the -number of PWM devices provided by the chip and the chip-specific -implementation of the supported PWM operations to the framework. +A new PWM controller/chip can be allocated using pwmchip_alloc(), then +registered using pwmchip_add() and removed again with pwmchip_remove(). To undo +pwmchip_alloc() use pwmchip_put(). pwmchip_add() takes a filled in struct +pwm_chip as argument which provides a description of the PWM chip, the number +of PWM devices provided by the chip and the chip-specific implementation of the +supported PWM operations to the framework. When implementing polarity support in a PWM driver, make sure to respect the signal conventions in the PWM framework. By definition, normal polarity diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 830a697826af..d70f793ce4b3 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -454,6 +454,64 @@ of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args) } EXPORT_SYMBOL_GPL(of_pwm_single_xlate); +#define PWMCHIP_ALIGN ARCH_DMA_MINALIGN + +static void *pwmchip_priv(struct pwm_chip *chip) +{ + return (void *)chip + ALIGN(sizeof(*chip), PWMCHIP_ALIGN); +} + +/* This is the counterpart to pwmchip_alloc() */ +void pwmchip_put(struct pwm_chip *chip) +{ + kfree(chip); +} +EXPORT_SYMBOL_GPL(pwmchip_put); + +struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv) +{ + struct pwm_chip *chip; + size_t alloc_size; + + alloc_size = size_add(ALIGN(sizeof(*chip), PWMCHIP_ALIGN), sizeof_priv); + + chip = kzalloc(alloc_size, GFP_KERNEL); + if (!chip) + return ERR_PTR(-ENOMEM); + + chip->dev = parent; + chip->npwm = npwm; + + pwmchip_set_drvdata(chip, pwmchip_priv(chip)); + + 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) diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 29a7d9140f77..4a6568dfdf3f 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -403,6 +403,10 @@ static inline bool pwm_might_sleep(struct pwm_device *pwm) int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result, unsigned long timeout); +void pwmchip_put(struct pwm_chip *chip); +struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv); +struct pwm_chip *devm_pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv); + int __pwmchip_add(struct pwm_chip *chip, struct module *owner); #define pwmchip_add(chip) __pwmchip_add(chip, THIS_MODULE) void pwmchip_remove(struct pwm_chip *chip); @@ -475,6 +479,24 @@ static inline int pwm_capture(struct pwm_device *pwm, return -EINVAL; } +static inline void pwmchip_put(struct pwm_chip *chip) +{ +} + +static inline struct pwm_chip *pwmchip_alloc(struct device *parent, + unsigned int npwm, + size_t sizeof_priv) +{ + return ERR_PTR(-EINVAL); +} + +static inline struct pwm_chip *devm_pwmchip_alloc(struct device *parent, + unsigned int npwm, + size_t sizeof_priv) +{ + return pwmchip_alloc(parent, npwm, sizeof_priv); +} + static inline int pwmchip_add(struct pwm_chip *chip) { return -EINVAL; |