[PATCH 10/13] drm/dp: Enable backlight control using luminance

[Murthy, Arun R]

> -----Original Message-----
> From: Kandpal, Suraj <suraj.kandpal at intel.com>
> Sent: Monday, April 14, 2025 9:47 AM
> To: nouveau at lists.freedesktop.org; dri-devel at lists.freedesktop.org; intel-
> xe at lists.freedesktop.org; intel-gfx at lists.freedesktop.org
> Cc: Nautiyal, Ankit K <ankit.k.nautiyal at intel.com>; Murthy, Arun R
> <arun.r.murthy at intel.com>; Kandpal, Suraj <suraj.kandpal at intel.com>
> Subject: [PATCH 10/13] drm/dp: Enable backlight control using luminance
> 
> Add flag to enable brightness control via luminance value when enabling edp
> backlight.
> 
> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> ---
>  drivers/gpu/drm/display/drm_dp_helper.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
> b/drivers/gpu/drm/display/drm_dp_helper.c
> index 0421b2ed9bd4..4e2caba8311a 100644
> --- a/drivers/gpu/drm/display/drm_dp_helper.c
> +++ b/drivers/gpu/drm/display/drm_dp_helper.c
> @@ -4030,6 +4030,9 @@ int drm_edp_backlight_enable(struct drm_dp_aux
> *aux, const struct drm_edp_backli
>  	else
>  		dpcd_buf = DP_EDP_BACKLIGHT_CONTROL_MODE_PWM;
> 
> +	if (bl->luminance_set)
> +		dpcd_buf |= DP_EDP_PANEL_LUMINANCE_CONTROL_ENABLE;
Can the backlight control by luminance be used along with PWM or AUX ctl?

Thanks and Regards,
Arun R Murthy
-------------------
> +
>  	if (bl->pwmgen_bit_count) {
>  		ret = drm_dp_dpcd_write_byte(aux,
> DP_EDP_PWMGEN_BIT_COUNT, bl->pwmgen_bit_count);
>  		if (ret < 0)
> --
> 2.34.1