[PATCH 3/7] drm/i915/backlight: Check Luminance based brightness control for VESA

[Murthy, Arun R]

> Check if we are capable of controlling brightness via luminance which is
> dependent on PANEL_LUMINANCE_OVERRIDE being set.
> 
Is PANEL_LUMINANCE_OVERRIDE a macro? I don't see this definition!

> --v2
> -Prefer using luminance rather than nits [Jani] -Fix commit message
> 
> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> Tested-by: Ben Kao <ben.kao at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display_types.h    | 1 +
>  drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 9 +++++++++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> b/drivers/gpu/drm/i915/display/intel_display_types.h
> index cb51b7936f93..3b64ad724b29 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -412,6 +412,7 @@ struct intel_panel {
>  		union {
>  			struct {
>  				struct drm_edp_backlight_info info;
> +				bool luminance_control_support;
>  			} vesa;
>  			struct {
>  				bool sdr_uses_aux;
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> index 09e82f24d030..84126e7d1716 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> @@ -575,6 +575,15 @@ intel_dp_aux_supports_vesa_backlight(struct
> intel_connector *connector)  {
>  	struct intel_display *display = to_intel_display(connector);
>  	struct intel_dp *intel_dp = intel_attached_dp(connector);
> +	struct intel_panel *panel = &connector->panel;
> +
> +	if ((intel_dp->edp_dpcd[2] &
> DP_EDP_PANEL_LUMINANCE_CONTROL_CAPABLE)) {

DP_EDP_PANEL_LUMINANCE_CONTROL_CAPABLE seems to be for EDP_GENERAL_CAP_2 register, addr is 0x703
But the dpcd offset referred over here is dpd[2] which is EDP_BACKLIGHT_ADJUSTMENT_CAP reg, addr 0x702

> +		drm_dbg_kms(display->drm,
> +			    "[CONNECTOR:%d:%s] AUX Luminance Based
> Backlight Control Supported!\n",
> +			    connector->base.base.id, connector->base.name);
> +		panel->backlight.edp.vesa.luminance_control_support = true;
> +		return true;
> +	}
> 
>  	if (drm_edp_backlight_supported(intel_dp->edp_dpcd)) {
>  		drm_dbg_kms(display->drm,
> --
> 2.34.1

Thanks and Regards,
Arun R Murthy
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