[PATCH v3 6/6] drm/rockchip: dw_hdmi_qp: Advertise BT.709 and BT.2020 colorimetries

[Chaoyi Chen]

Hi Jan,

On 10/18/2026 8:30 PM, Jan Claußen wrote:
> Expose BT.2020 RGB and YCC colorimetry so userspace can enable HDR
> output. Also explicitly expose BT.709 YCC as it is listed in the
> Rockchip RK3588 TRM V1.0-Part2 20220309 data sheet.
> 
> Tested on a Radxa Rock 5B (RK3588) with an LG OLED55B87LC in KDE
> Plasma 6.7.5: enabling HDR switches the colorspace to BT.2020, and
> disabling it restores the default.
> 
> Signed-off-by: Jan Claußen <jan.claussen10 at web.de>
> ---
> 
> Not sure if BT.709 needs to be explicitly exposed here, but it is mentioned in the data sheet.
> Might be covered by DRM_MODE_COLORIMETRY_DEFAULT though.

Cc: Cristian Ciocaltea <cristian.ciocaltea at collabora.com>

Hi Cristian, may be you would be interested in this series?

"DEFAULT" may refer to either BT.601 or BT.709. It should support the
following color spaces:

#define HDMI_COLORSPACE_CAPS_V1		(DRM_MODE_COLORIMETRY_DEFAULT | \
					DRM_MODE_COLORIMETRY_SMPTE_170M_YCC | \
					DRM_MODE_COLORIMETRY_BT709_YCC | \
					DRM_MODE_COLORIMETRY_BT2020_RGB)

#define HDMI_COLORSPACE_CAPS_V2		(HDMI_COLORSPACE_CAPS_V1 | \
					DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65)

> 
> BT.709/BT.2020 YCC are untested.
> 
>  drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
> index 9c4cf68d79d5..dbb87dfd000c 100644
> --- a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
> @@ -605,6 +605,10 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
>  				      BIT(DRM_OUTPUT_COLOR_FORMAT_YCBCR444) |
>  				      BIT(DRM_OUTPUT_COLOR_FORMAT_YCBCR422);
>  
> +	plat_data.supported_colorspaces = BIT(DRM_MODE_COLORIMETRY_BT709_YCC) |
> +				      BIT(DRM_MODE_COLORIMETRY_BT2020_RGB) |
> +				      BIT(DRM_MODE_COLORIMETRY_BT2020_YCC);
> +
>  	encoder = &hdmi->encoder.encoder;
>  	encoder->possible_crtcs = drm_of_find_possible_crtcs(drm, dev->of_node);
>  

-- 
Best, 
Chaoyi