The PWM state, represented by its period, duty_cycle and polarity, is currently directly stored in the PWM device. Declare a pwm_state structure embedding those field so that we can later use this struct to atomically update all the PWM parameters at once.
All pwm_get_xxx() helpers are now implemented as wrappers around pwm_get_state().
Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/pwm/core.c | 8 ++++---- include/linux/pwm.h | 54 +++++++++++++++++++++++++++++++++++++++++------------ 2 files changed, 46 insertions(+), 16 deletions(-)
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 6433059..f3f91e7 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -268,7 +268,7 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip, pwm->chip = chip; pwm->pwm = chip->base + i; pwm->hwpwm = i; - pwm->polarity = polarity; + pwm->state.polarity = polarity;
radix_tree_insert(&pwm_tree, pwm->pwm, pwm); } @@ -446,8 +446,8 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) if (err) return err;
- pwm->duty_cycle = duty_ns; - pwm->period = period_ns; + pwm->state.duty_cycle = duty_ns; + pwm->state.period = period_ns;
return 0; } @@ -480,7 +480,7 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) if (err) return err;
- pwm->polarity = polarity; + pwm->state.polarity = polarity;
return 0; } diff --git a/include/linux/pwm.h b/include/linux/pwm.h index ed65354..f0f0f37 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -97,6 +97,18 @@ enum { PWMF_EXPORTED = 1 << 2, };
+/* + * struct pwm_state - state of a PWM channel + * @period: PWM period (in nanoseconds) + * @duty_cycle: PWM duty cycle (in nanoseconds) + * @polarity: PWM polarity + */ +struct pwm_state { + unsigned int period; + unsigned int duty_cycle; + enum pwm_polarity polarity; +}; + /** * struct pwm_device - PWM channel object * @label: name of the PWM device @@ -105,10 +117,8 @@ enum { * @pwm: global index of the PWM device * @chip: PWM chip providing this PWM device * @chip_data: chip-private data associated with the PWM device - * @period: period of the PWM signal (in nanoseconds) - * @duty_cycle: duty cycle of the PWM signal (in nanoseconds) - * @polarity: polarity of the PWM signal * @args: PWM arguments + * @state: curent PWM channel state */ struct pwm_device { const char *label; @@ -118,13 +128,21 @@ struct pwm_device { struct pwm_chip *chip; void *chip_data;
- unsigned int period; - unsigned int duty_cycle; - enum pwm_polarity polarity; - struct pwm_args args; + struct pwm_state state; };
+/** + * pwm_get_state() - retrieve the current PWM state + * @pwm: PWM device + * @state: state to fill with the current PWM state + */ +static inline void pwm_get_state(const struct pwm_device *pwm, + struct pwm_state *state) +{ + *state = pwm->state; +} + static inline bool pwm_is_enabled(const struct pwm_device *pwm) { return test_bit(PWMF_ENABLED, &pwm->flags); @@ -133,23 +151,31 @@ static inline bool pwm_is_enabled(const struct pwm_device *pwm) static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period) { if (pwm) - pwm->period = period; + pwm->state.period = period; }
static inline unsigned int pwm_get_period(const struct pwm_device *pwm) { - return pwm ? pwm->period : 0; + struct pwm_state pstate; + + pwm_get_state(pwm, &pstate); + + return pstate.period; }
static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty) { if (pwm) - pwm->duty_cycle = duty; + pwm->state.duty_cycle = duty; }
static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm) { - return pwm ? pwm->duty_cycle : 0; + struct pwm_state pstate; + + pwm_get_state(pwm, &pstate); + + return pstate.duty_cycle; }
/* @@ -159,7 +185,11 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm) { - return pwm ? pwm->polarity : PWM_POLARITY_NORMAL; + struct pwm_state pstate; + + pwm_get_state(pwm, &pstate); + + return pstate.polarity; }
static inline void pwm_get_args(const struct pwm_device *pwm,