diff options
Diffstat (limited to 'include/pwm.h')
| -rw-r--r-- | include/pwm.h | 101 |
1 files changed, 85 insertions, 16 deletions
diff --git a/include/pwm.h b/include/pwm.h index ca01f5b53d..4d403fe174 100644 --- a/include/pwm.h +++ b/include/pwm.h @@ -2,8 +2,29 @@ #ifndef __PWM_H #define __PWM_H +#include <dt-bindings/pwm/pwm.h> +#include <errno.h> + struct pwm_device; -struct device_d; +struct device; + +#define PWM_POLARITY_NORMAL 0 + +/* + * struct pwm_state - state of a PWM channel + * @period_ns: PWM period (in nanoseconds) + * @duty_ns: PWM duty cycle (in nanoseconds) + * @polarity: PWM polarity + * @p_enable: PWM enabled status + */ +struct pwm_state { + unsigned int period_ns; + unsigned int duty_ns; + unsigned int polarity; + unsigned int p_enable; +}; + +void pwm_print(void); /* * pwm_request - request a PWM device @@ -18,6 +39,17 @@ struct pwm_device *of_pwm_request(struct device_node *np, const char *con_id); void pwm_free(struct pwm_device *pwm); /* + * pwm_init_state - prepare a new state from device tree args + */ +void pwm_init_state(const struct pwm_device *pwm, + struct pwm_state *state); + +/* + * pwm_config - change a PWM device configuration + */ +int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state); + +/* * pwm_config - change a PWM device configuration */ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns); @@ -32,28 +64,66 @@ int pwm_enable(struct pwm_device *pwm); */ void pwm_disable(struct pwm_device *pwm); -void pwm_set_period(struct pwm_device *pwm, unsigned int period); unsigned int pwm_get_period(struct pwm_device *pwm); -void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty); -unsigned int pwm_get_duty_cycle(struct pwm_device *pwm); + +/** + * pwm_set_relative_duty_cycle() - Set a relative duty cycle value + * @state: PWM state to fill + * @duty_cycle: relative duty cycle value + * @scale: scale in which @duty_cycle is expressed + * + * This functions converts a relative into an absolute duty cycle (expressed + * in nanoseconds), and puts the result in state->duty_ns. + * + * For example if you want to configure a 50% duty cycle, call: + * + * pwm_init_state(pwm, &state); + * pwm_set_relative_duty_cycle(&state, 50, 100); + * pwm_apply_state(pwm, &state); + * + * This functions returns -EINVAL if @duty_cycle and/or @scale are + * inconsistent (@scale == 0 or @duty_cycle > @scale). + */ +static inline int +pwm_set_relative_duty_cycle(struct pwm_state *state, unsigned int duty_cycle, + unsigned int scale) +{ + if (!scale || duty_cycle > scale) + return -EINVAL; + + state->duty_ns = DIV_ROUND_CLOSEST_ULL((u64)duty_cycle * + state->period_ns, + scale); + + return 0; +} struct pwm_chip; /** + * pwm_get_state() - retrieve the current PWM state + * @pwm: PWM device + * @state: state to fill with the current PWM state + */ +void pwm_get_state(const struct pwm_device *pwm, struct pwm_state *state); + +/** + * pwm_apply_state() - apply the passed PWM state + * @pwm: PWM device + * @state: state to apply to pwm device + */ +int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state); + +/** * struct pwm_ops - PWM 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 - * @enable: enable PWM output toggling - * @disable: disable PWM output toggling + * @apply: apply specified pwm state */ struct pwm_ops { int (*request)(struct pwm_chip *chip); void (*free)(struct pwm_chip *chip); - int (*config)(struct pwm_chip *chip, int duty_ns, - int period_ns); - int (*enable)(struct pwm_chip *chip); - void (*disable)(struct pwm_chip *chip); + int (*apply)(struct pwm_chip *chip, const struct pwm_state *state); }; /** @@ -61,18 +131,17 @@ struct pwm_ops { * @id: The id of this pwm * @devname: unique identifier for this pwm * @ops: The callbacks for this PWM - * @duty_ns: The duty cycle of the PWM, in nano-seconds - * @period_ns: The period of the PWM, in nano-seconds + * @state: current state of the PWM */ struct pwm_chip { int id; const char *devname; const struct pwm_ops *ops; - int duty_ns; - int period_ns; + + struct pwm_state state; }; -int pwmchip_add(struct pwm_chip *chip, struct device_d *dev); +int pwmchip_add(struct pwm_chip *chip, struct device *dev); int pwmchip_remove(struct pwm_chip *chip); #endif /* __PWM_H */ |