[RFC PATCH 10/15] pwm: add the PWM initial state retrieval infra

On Mon, 20 Jul 2015 11:01:24 +0200
Thierry Reding [off-list ref] wrote:

On Wed, Jul 01, 2015 at 10:21:56AM +0200, Boris Brezillon wrote:

quoted

Add a ->init_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 <redacted>
---
 drivers/pwm/core.c  | 3 +++
 include/linux/pwm.h | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 3e830ce..30631f5 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c

@@ -264,6 +264,9 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
 		pwm->hwpwm = i;
 		pwm_set_default_polarity(pwm, polarity);
 
+		if (chip->ops->init_state)
+			chip->ops->init_state(chip, pwm);
+
 		radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
 	}
 

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 0f36a06..b47244a 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h

@@ -177,6 +177,8 @@ struct pwm_ops {
 					  struct pwm_device *pwm);
 	void			(*disable)(struct pwm_chip *chip,
 					   struct pwm_device *pwm);
+	void			(*init_state)(struct pwm_chip *chip,
+					      struct pwm_device *pwm);

I think I'd call this reset_state. init has this connotation of setting
a set of default values. For reset it's clearer in my opinion that it's
resetting to the hardware state.

I'm fine with the reset_state name, I'll change that in my v2.

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com