[PATCH v4 15/24] pwm: define a new pwm_state struct

Boris Brezillon
2015-11-16T09:00:28Z

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.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
drivers/pwm/core.c | 6 +++---
include/linux/pwm.h | 30 +++++++++++++++++++-----------
2 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 59073a1..f1c6769 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -447,8 +447,8 @@ 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;
}
@@ -485,7 +485,7 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
if (err)
goto unlock;

- pwm->polarity = polarity;
+ pwm->state.polarity = polarity;

unlock:
mutex_unlock(&pwm->lock);
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 8ba57fc..af42299 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -80,6 +80,18 @@ 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
@@ -89,9 +101,7 @@ enum {
* @chip: PWM chip providing this PWM device
* @chip_data: chip-private data associated with the PWM device
* @lock: used to serialize accesses to the PWM device where necessary
- * @period: period of the PWM signal (in nanoseconds)
- * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
- * @polarity: polarity of the PWM signal
+ * @state: curent PWM channel state
*/
struct pwm_device {
const char *label;
@@ -102,9 +112,7 @@ struct pwm_device {
void *chip_data;
struct mutex lock;

- unsigned int period;
- unsigned int duty_cycle;
- enum pwm_polarity polarity;
+ struct pwm_state state;
};

static inline bool pwm_is_enabled(const struct pwm_device *pwm)
@@ -115,7 +123,7 @@ 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 void pwm_set_default_period(struct pwm_device *pwm,
@@ -126,7 +134,7 @@ static inline void pwm_set_default_period(struct pwm_device *pwm,

static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
{
- return pwm ? pwm->period : 0;
+ return pwm ? pwm->state.period : 0;
}

static inline unsigned int pwm_get_default_period(const struct pwm_device *pwm)
@@ -137,12 +145,12 @@ static inline unsigned int pwm_get_default_period(const struct pwm_device *pwm)
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;
+ return pwm ? pwm->state.duty_cycle : 0;
}

/*
@@ -158,7 +166,7 @@ static inline void pwm_set_default_polarity(struct pwm_device *pwm,

static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
{
- return pwm ? pwm->polarity : PWM_POLARITY_NORMAL;
+ return pwm ? pwm->state.polarity : PWM_POLARITY_NORMAL;
}

/**
--
2.1.4