[PATCH v4 16/24] pwm: move the enabled/disabled info to pwm_state struct

Boris Brezillon
2015-11-16T09:00:32Z

Prepare the transition to PWM atomic update by moving the enabled/disabled
state into the pwm_state struct. This way we can easily update the whole
PWM state by copying the new state in the ->state field.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
drivers/pwm/core.c | 17 +++++++++++++----
include/linux/pwm.h | 7 ++++---
2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index f1c6769..6bbda6c 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -508,10 +508,10 @@ int pwm_enable(struct pwm_device *pwm)

mutex_lock(&pwm->lock);

- if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) {
+ if (!pwm_is_enabled(pwm)) {
err = pwm->chip->ops->enable(pwm->chip, pwm);
- if (err)
- clear_bit(PWMF_ENABLED, &pwm->flags);
+ if (!err)
+ pwm->state.enabled = true;
}

mutex_unlock(&pwm->lock);
@@ -526,8 +526,17 @@ EXPORT_SYMBOL_GPL(pwm_enable);
*/
void pwm_disable(struct pwm_device *pwm)
{
- if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
+ if (!pwm)
+ return;
+
+ mutex_lock(&pwm->lock);
+
+ if (pwm_is_enabled(pwm)) {
pwm->chip->ops->disable(pwm->chip, pwm);
+ pwm->state.enabled = false;
+ }
+
+ mutex_unlock(&pwm->lock);
}
EXPORT_SYMBOL_GPL(pwm_disable);

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index af42299..398c58c 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -76,8 +76,7 @@ enum pwm_polarity {

enum {
PWMF_REQUESTED = 1 << 0,
- PWMF_ENABLED = 1 << 1,
- PWMF_EXPORTED = 1 << 2,
+ PWMF_EXPORTED = 1 << 1,
};

/*
@@ -85,11 +84,13 @@ enum {
* @period: PWM period (in nanoseconds)
* @duty_cycle: PWM duty cycle (in nanoseconds)
* @polarity: PWM polarity
+ * @enabled: PWM enabled status
*/
struct pwm_state {
unsigned int period;
unsigned int duty_cycle;
enum pwm_polarity polarity;
+ bool enabled;
};

/**
@@ -117,7 +118,7 @@ struct pwm_device {

static inline bool pwm_is_enabled(const struct pwm_device *pwm)
{
- return test_bit(PWMF_ENABLED, &pwm->flags);
+ return pwm->state.enabled;
}

static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
--
2.1.4