[PATCH v5 17/46] pwm: add the PWM initial state retrieval infra

Boris Brezillon
2016-03-30T20:05:05Z

Add a ->get_state() function to the pwm_ops struct to let PWM drivers
initialize the PWM state attached to a PWM device.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
drivers/pwm/core.c | 3 +++
include/linux/pwm.h | 5 +++++
2 files changed, 8 insertions(+)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index c240b54..a909c64 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -270,6 +270,9 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
pwm->hwpwm = i;
pwm->state.polarity = polarity;

+ if (chip->ops->get_state)
+ chip->ops->get_state(chip, pwm, &pwm->state);
+
radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
}

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 55bf463..ceedcf8 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -211,6 +211,9 @@ static inline void pwm_get_args(const struct pwm_device *pwm,
* @set_polarity: configure the polarity of this PWM
* @enable: enable PWM output toggling
* @disable: disable PWM output toggling
+ * @get_state: get the current PWM state. This function is only
+ * called once per PWM device when the PWM chip is
+ * registered.
* @dbg_show: optional routine to show contents in debugfs
* @owner: helps prevent removal of modules exporting active PWMs
*/
@@ -223,6 +226,8 @@ struct pwm_ops {
enum pwm_polarity polarity);
int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
+ void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *pstate);
#ifdef CONFIG_DEBUG_FS
void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s);
#endif
--
2.5.0