diff options
Diffstat (limited to 'kernel/include/linux/pwm.h')
| -rw-r--r-- | kernel/include/linux/pwm.h | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/kernel/include/linux/pwm.h b/kernel/include/linux/pwm.h new file mode 100644 index 000000000..e90628cac --- /dev/null +++ b/kernel/include/linux/pwm.h @@ -0,0 +1,312 @@ +#ifndef __LINUX_PWM_H +#define __LINUX_PWM_H + +#include <linux/err.h> +#include <linux/of.h> + +struct pwm_device; +struct seq_file; + +#if IS_ENABLED(CONFIG_PWM) +/* + * pwm_request - request a PWM device + */ +struct pwm_device *pwm_request(int pwm_id, const char *label); + +/* + * pwm_free - free a PWM device + */ +void pwm_free(struct pwm_device *pwm); + +/* + * pwm_config - change a PWM device configuration + */ +int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns); + +/* + * pwm_enable - start a PWM output toggling + */ +int pwm_enable(struct pwm_device *pwm); + +/* + * pwm_disable - stop a PWM output toggling + */ +void pwm_disable(struct pwm_device *pwm); +#else +static inline struct pwm_device *pwm_request(int pwm_id, const char *label) +{ + return ERR_PTR(-ENODEV); +} + +static inline void pwm_free(struct pwm_device *pwm) +{ +} + +static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) +{ + return -EINVAL; +} + +static inline int pwm_enable(struct pwm_device *pwm) +{ + return -EINVAL; +} + +static inline void pwm_disable(struct pwm_device *pwm) +{ +} +#endif + +struct pwm_chip; + +/** + * enum pwm_polarity - polarity of a PWM signal + * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty- + * cycle, followed by a low signal for the remainder of the pulse + * period + * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty- + * cycle, followed by a high signal for the remainder of the pulse + * period + */ +enum pwm_polarity { + PWM_POLARITY_NORMAL, + PWM_POLARITY_INVERSED, +}; + +enum { + PWMF_REQUESTED = 1 << 0, + PWMF_ENABLED = 1 << 1, + PWMF_EXPORTED = 1 << 2, +}; + +struct pwm_device { + const char *label; + unsigned long flags; + unsigned int hwpwm; + unsigned int pwm; + struct pwm_chip *chip; + void *chip_data; + + unsigned int period; /* in nanoseconds */ + unsigned int duty_cycle; /* in nanoseconds */ + enum pwm_polarity polarity; +}; + +static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period) +{ + if (pwm) + pwm->period = period; +} + +static inline unsigned int pwm_get_period(struct pwm_device *pwm) +{ + return pwm ? pwm->period : 0; +} + +static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty) +{ + if (pwm) + pwm->duty_cycle = duty; +} + +static inline unsigned int pwm_get_duty_cycle(struct pwm_device *pwm) +{ + return pwm ? pwm->duty_cycle : 0; +} + +/* + * pwm_set_polarity - configure the polarity of a PWM signal + */ +int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity); + +/** + * struct pwm_ops - PWM controller operations + * @request: optional hook for requesting a PWM + * @free: optional hook for freeing a PWM + * @config: configure duty cycles and period length for this PWM + * @set_polarity: configure the polarity of this PWM + * @enable: enable PWM output toggling + * @disable: disable PWM output toggling + * @dbg_show: optional routine to show contents in debugfs + * @owner: helps prevent removal of modules exporting active PWMs + */ +struct pwm_ops { + int (*request)(struct pwm_chip *chip, + struct pwm_device *pwm); + void (*free)(struct pwm_chip *chip, + struct pwm_device *pwm); + int (*config)(struct pwm_chip *chip, + struct pwm_device *pwm, + int duty_ns, int period_ns); + int (*set_polarity)(struct pwm_chip *chip, + struct pwm_device *pwm, + enum pwm_polarity polarity); + int (*enable)(struct pwm_chip *chip, + struct pwm_device *pwm); + void (*disable)(struct pwm_chip *chip, + struct pwm_device *pwm); +#ifdef CONFIG_DEBUG_FS + void (*dbg_show)(struct pwm_chip *chip, + struct seq_file *s); +#endif + struct module *owner; +}; + +/** + * struct pwm_chip - abstract a PWM controller + * @dev: device providing the PWMs + * @list: list node for internal use + * @ops: callbacks for this PWM controller + * @base: number of first PWM controlled by this chip + * @npwm: number of PWMs controlled by this chip + * @pwms: array of PWM devices allocated by the framework + * @can_sleep: must be true if the .config(), .enable() or .disable() + * operations may sleep + */ +struct pwm_chip { + struct device *dev; + struct list_head list; + const struct pwm_ops *ops; + int base; + unsigned int npwm; + + struct pwm_device *pwms; + + struct pwm_device * (*of_xlate)(struct pwm_chip *pc, + const struct of_phandle_args *args); + unsigned int of_pwm_n_cells; + bool can_sleep; +}; + +#if IS_ENABLED(CONFIG_PWM) +int pwm_set_chip_data(struct pwm_device *pwm, void *data); +void *pwm_get_chip_data(struct pwm_device *pwm); + +int pwmchip_add(struct pwm_chip *chip); +int pwmchip_remove(struct pwm_chip *chip); +struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, + unsigned int index, + const char *label); + +struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc, + const struct of_phandle_args *args); + +struct pwm_device *pwm_get(struct device *dev, const char *con_id); +struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id); +void pwm_put(struct pwm_device *pwm); + +struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id); +struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, + const char *con_id); +void devm_pwm_put(struct device *dev, struct pwm_device *pwm); + +bool pwm_can_sleep(struct pwm_device *pwm); +#else +static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data) +{ + return -EINVAL; +} + +static inline void *pwm_get_chip_data(struct pwm_device *pwm) +{ + return NULL; +} + +static inline int pwmchip_add(struct pwm_chip *chip) +{ + return -EINVAL; +} + +static inline int pwmchip_remove(struct pwm_chip *chip) +{ + return -EINVAL; +} + +static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, + unsigned int index, + const char *label) +{ + return ERR_PTR(-ENODEV); +} + +static inline struct pwm_device *pwm_get(struct device *dev, + const char *consumer) +{ + return ERR_PTR(-ENODEV); +} + +static inline struct pwm_device *of_pwm_get(struct device_node *np, + const char *con_id) +{ + return ERR_PTR(-ENODEV); +} + +static inline void pwm_put(struct pwm_device *pwm) +{ +} + +static inline struct pwm_device *devm_pwm_get(struct device *dev, + const char *consumer) +{ + return ERR_PTR(-ENODEV); +} + +static inline struct pwm_device *devm_of_pwm_get(struct device *dev, + struct device_node *np, + const char *con_id) +{ + return ERR_PTR(-ENODEV); +} + +static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm) +{ +} + +static inline bool pwm_can_sleep(struct pwm_device *pwm) +{ + return false; +} +#endif + +struct pwm_lookup { + struct list_head list; + const char *provider; + unsigned int index; + const char *dev_id; + const char *con_id; + unsigned int period; + enum pwm_polarity polarity; +}; + +#define PWM_LOOKUP(_provider, _index, _dev_id, _con_id, _period, _polarity) \ + { \ + .provider = _provider, \ + .index = _index, \ + .dev_id = _dev_id, \ + .con_id = _con_id, \ + .period = _period, \ + .polarity = _polarity \ + } + +#if IS_ENABLED(CONFIG_PWM) +void pwm_add_table(struct pwm_lookup *table, size_t num); +#else +static inline void pwm_add_table(struct pwm_lookup *table, size_t num) +{ +} +#endif + +#ifdef CONFIG_PWM_SYSFS +void pwmchip_sysfs_export(struct pwm_chip *chip); +void pwmchip_sysfs_unexport(struct pwm_chip *chip); +#else +static inline void pwmchip_sysfs_export(struct pwm_chip *chip) +{ +} + +static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip) +{ +} +#endif /* CONFIG_PWM_SYSFS */ + +#endif /* __LINUX_PWM_H */ |