Re: [PATCH 1/9] backlight: atmel-pwm-bl: fix reported brightness

[Jingoo Han]

On Wednesday, October 23, 2013 2:27 AM, Johan Hovold wrote:
> 
> The driver supports 16-bit brightness values, but the value returned
> from get_brightness was truncated to eight bits.
> 
> Cc: sta...@vger.kernel.org
> Signed-off-by: Johan Hovold <jhov...@gmail.com>
> ---
>  drivers/video/backlight/atmel-pwm-bl.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/video/backlight/atmel-pwm-bl.c 
> b/drivers/video/backlight/atmel-pwm-bl.c
> index 66885fb..8aac273 100644
> --- a/drivers/video/backlight/atmel-pwm-bl.c
> +++ b/drivers/video/backlight/atmel-pwm-bl.c
> @@ -70,7 +70,7 @@ static int atmel_pwm_bl_set_intensity(struct 
> backlight_device *bd)
>  static int atmel_pwm_bl_get_intensity(struct backlight_device *bd)
>  {
>       struct atmel_pwm_bl *pwmbl = bl_get_data(bd);
> -     u8 intensity;
> +     u32 intensity;
> 
>       if (pwmbl->pdata->pwm_active_low) {
>               intensity = pwm_channel_readl(&pwmbl->pwmc, PWM_CDTY) -
> @@ -80,7 +80,7 @@ static int atmel_pwm_bl_get_intensity(struct 
> backlight_device *bd)
>                       pwm_channel_readl(&pwmbl->pwmc, PWM_CDTY);
>       }
> 
> -     return intensity;
> +     return (u16)intensity;

However, atmel_pwm_bl_get_intensity() should return 'int',
instead of 'u16'. Also, pwm_channel_readl() returns 'u32'.

Then, how about the following?

--- a/drivers/video/backlight/atmel-pwm-bl.c
+++ b/drivers/video/backlight/atmel-pwm-bl.c
@@ -70,17 +70,17 @@ static int atmel_pwm_bl_set_intensity(struct 
backlight_device *bd)
 static int atmel_pwm_bl_get_intensity(struct backlight_device *bd)
 {
        struct atmel_pwm_bl *pwmbl = bl_get_data(bd);
-       u8 intensity;
+       u16 intensity;

        if (pwmbl->pdata->pwm_active_low) {
-               intensity = pwm_channel_readl(&pwmbl->pwmc, PWM_CDTY) -
+               intensity = (u16) pwm_channel_readl(&pwmbl->pwmc, PWM_CDTY) -
                        pwmbl->pdata->pwm_duty_min;
        } else {
-               intensity = pwmbl->pdata->pwm_duty_max -
+               intensity = (u16) pwmbl->pdata->pwm_duty_max -
                        pwm_channel_readl(&pwmbl->pwmc, PWM_CDTY);
        }

-       return intensity;
+       return (int)intensity;
 }

Best regards,
Jingoo Han

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