Re: [PATCH v4] backlight: lp855x: Switch to atomic PWM API

2021-11-02 Thread Daniel Thompson
On Mon, Nov 01, 2021 at 10:19:21AM -0300, Maíra Canal wrote:
> Remove legacy PWM interface (pwm_config, pwm_enable, pwm_disable) and
> replace it for the atomic PWM API.
> 
> Signed-off-by: Maíra Canal 
> ---
> V1 -> V2: Initialize variable and simply conditional loop
> V2 -> V3: Fix assignment of NULL variable
> V3 -> V4: Replace division for pwm_set_relative_duty_cycle
> ---
>  drivers/video/backlight/lp855x_bl.c | 20 
>  1 file changed, 8 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/video/backlight/lp855x_bl.c 
> b/drivers/video/backlight/lp855x_bl.c
> index e94932c69f54..bbf24564082a 100644
> --- a/drivers/video/backlight/lp855x_bl.c
> +++ b/drivers/video/backlight/lp855x_bl.c
> @@ -233,9 +233,8 @@ static int lp855x_configure(struct lp855x *lp)
>  
>  static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
>  {
> - unsigned int period = lp->pdata->period_ns;
> - unsigned int duty = br * period / max_br;
>   struct pwm_device *pwm;
> + struct pwm_state state;
>  
>   /* request pwm device with the consumer name */
>   if (!lp->pwm) {
> @@ -245,18 +244,15 @@ static void lp855x_pwm_ctrl(struct lp855x *lp, int br, 
> int max_br)
>  
>   lp->pwm = pwm;
>  
> - /*
> -  * FIXME: pwm_apply_args() should be removed when switching to
> -  * the atomic PWM API.
> -  */
> - pwm_apply_args(pwm);
> + pwm_init_state(lp->pwm, );
> + state.period = lp->pdata->period_ns;
>   }
>  
> - pwm_config(lp->pwm, duty, period);
> - if (duty)
> - pwm_enable(lp->pwm);
> - else
> - pwm_disable(lp->pwm);
> + pwm_get_state(lp->pwm, );

Should this be:

} else {
pwm_get_state(lp->pwm, );
}

As currently written this will clobber the state.period that was set
above.


Daniel.


> + pwm_set_relative_duty_cycle(, br, max_br);
> + state.enabled = state.duty_cycle;
> +
> + pwm_apply_state(lp->pwm, );
>  }
>  
>  static int lp855x_bl_update_status(struct backlight_device *bl)
> -- 
> 2.31.1
> 


[PATCH v4] backlight: lp855x: Switch to atomic PWM API

2021-11-01 Thread Maíra Canal
Remove legacy PWM interface (pwm_config, pwm_enable, pwm_disable) and
replace it for the atomic PWM API.

Signed-off-by: Maíra Canal 
---
V1 -> V2: Initialize variable and simply conditional loop
V2 -> V3: Fix assignment of NULL variable
V3 -> V4: Replace division for pwm_set_relative_duty_cycle
---
 drivers/video/backlight/lp855x_bl.c | 20 
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/video/backlight/lp855x_bl.c 
b/drivers/video/backlight/lp855x_bl.c
index e94932c69f54..bbf24564082a 100644
--- a/drivers/video/backlight/lp855x_bl.c
+++ b/drivers/video/backlight/lp855x_bl.c
@@ -233,9 +233,8 @@ static int lp855x_configure(struct lp855x *lp)
 
 static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
 {
-   unsigned int period = lp->pdata->period_ns;
-   unsigned int duty = br * period / max_br;
struct pwm_device *pwm;
+   struct pwm_state state;
 
/* request pwm device with the consumer name */
if (!lp->pwm) {
@@ -245,18 +244,15 @@ static void lp855x_pwm_ctrl(struct lp855x *lp, int br, 
int max_br)
 
lp->pwm = pwm;
 
-   /*
-* FIXME: pwm_apply_args() should be removed when switching to
-* the atomic PWM API.
-*/
-   pwm_apply_args(pwm);
+   pwm_init_state(lp->pwm, );
+   state.period = lp->pdata->period_ns;
}
 
-   pwm_config(lp->pwm, duty, period);
-   if (duty)
-   pwm_enable(lp->pwm);
-   else
-   pwm_disable(lp->pwm);
+   pwm_get_state(lp->pwm, );
+   pwm_set_relative_duty_cycle(, br, max_br);
+   state.enabled = state.duty_cycle;
+
+   pwm_apply_state(lp->pwm, );
 }
 
 static int lp855x_bl_update_status(struct backlight_device *bl)
-- 
2.31.1