[PATCH v2 03/24] backlight: Add get/set operations for brightness properties

[Daniel Thompson]

On Sun, Aug 23, 2020 at 12:45:11PM +0200, Sam Ravnborg wrote:
> Add get and set operations to incapsualte access to backlight brightness.
> 
> One easy win is that the get/set operations can be used when backlight
> is not included in the configuration, resulting in simpler code with
> less ifdef's and thus more readable code.
> 
> The backlight_enable_brightness() update the brightness and enable
> the backlight.
> 
> The backlight_update_brightness() force the brightness update and
> typical usage is to set brightness after registering a backlight device.
> 
> Signed-off-by: Sam Ravnborg <sam at ravnborg.org>
> Cc: Lee Jones <lee.jones at linaro.org>
> Cc: Daniel Thompson <daniel.thompson at linaro.org>
> Cc: Jingoo Han <jingoohan1 at gmail.com>

Reviewed-by: Daniel Thompson <daniel.thompson at linaro.org>


> ---
>  include/linux/backlight.h | 74 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 74 insertions(+)
> 
> diff --git a/include/linux/backlight.h b/include/linux/backlight.h
> index 93a47a6cf681..e390444bed13 100644
> --- a/include/linux/backlight.h
> +++ b/include/linux/backlight.h
> @@ -492,6 +492,80 @@ static inline int backlight_get_brightness(const struct backlight_device *bd)
>  		return bd->props.brightness;
>  }
>  
> +/**
> + * backlight_get_actual_brightness - Returns the actual brightness
> + *
> + * On failure a negative error code is returned.
> + */
> +static inline int backlight_get_actual_brightness(struct backlight_device *bd)
> +{
> +	if (bd && bd->ops && bd->ops->get_brightness)
> +		return bd->ops->get_brightness(bd);
> +	else
> +		return -EINVAL;
> +}
> +
> +/**
> + * backlight_get_max_brightness - Returns maximum brightness
> + *
> + * This helper operation is preferred over direct access to
> + * &backlight_properties.max_brightness
> + *
> + * Returns 0 if backlight_device is NULL
> + */
> +
> +static inline int backlight_get_max_brightness(const struct backlight_device *bd)
> +{
> +	if (bd)
> +		return bd->props.max_brightness;
> +	else
> +		return 0;
> +}
> +
> +/**
> + * backlight_set_brightness - Set the brightness to the specified value
> + *
> + * This helper operation is preferred over direct assignment to
> + * &backlight_properties.brightness.
> + *
> + * If backlight_device is NULL then silently exit.
> + */
> +static inline void backlight_set_brightness(struct backlight_device *bd, int brightness)
> +{
> +	if (bd)
> +		bd->props.brightness = brightness;
> +}
> +
> +/**
> + * backlight_update_brightness - Update the brightness to the specified value
> + *
> + * Update brightness and force an update.
> + *
> + * If backlight_device is NULL then silently exit.
> + */
> +static inline void backlight_update_brightness(struct backlight_device *bd, int brightness)
> +{
> +	if (bd) {
> +		bd->props.brightness = brightness;
> +		backlight_update_status(bd);
> +	}
> +}
> +
> +/**
> + * backlight_enable_brightness - Enable backligt using specified brightness
> + *
> + * Enable brightness using the specified brightness.
> + *
> + * If backlight_device is NULL then silently exit.
> + */
> +static inline void backlight_enable_brightness(struct backlight_device *bd, int brightness)
> +{
> +	if (bd) {
> +		bd->props.brightness = brightness;
> +		backlight_enable(bd);
> +	}
> +}
> +
>  struct backlight_device *
>  backlight_device_register(const char *name, struct device *dev, void *devdata,
>  			  const struct backlight_ops *ops,
> -- 
> 2.25.1
>