drm/rockchip: analogix_dp: correct the connector display color format and bpc

Rockchip VOP couldn't output YUV video format for eDP controller, so
when driver detect connector support YUV video format, we need to hack
it down to RGB888.
Signed-off-by: Yakir Yang <ykk@rock-chips.com>
Acked-by: Mark Yao <mark.yao@rock-chips.com>
Reviewed-by: Tomasz Figa <tomasz.figa@chromium.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>

drivers/gpu/drm/rockchip/analogix_dp-rockchip.c

@@ -110,6 +110,23 @@ static int rockchip_dp_powerdown(struct analogix_dp_plat_data *plat_data)
 	return 0;
 }
 
+static int rockchip_dp_get_modes(struct analogix_dp_plat_data *plat_data,
+				 struct drm_connector *connector)
+{
+	struct drm_display_info *di = &connector->display_info;
+	/* VOP couldn't output YUV video format for eDP rightly */
+	u32 mask = DRM_COLOR_FORMAT_YCRCB444 | DRM_COLOR_FORMAT_YCRCB422;
+
+	if ((di->color_formats & mask)) {
+		DRM_DEBUG_KMS("Swapping display color format from YUV to RGB\n");
+		di->color_formats &= ~mask;
+		di->color_formats |= DRM_COLOR_FORMAT_RGB444;
+		di->bpc = 8;
+	}
+
+	return 0;
+}
+
 static bool
 rockchip_dp_drm_encoder_mode_fixup(struct drm_encoder *encoder,
 				   const struct drm_display_mode *mode,
@@ -310,6 +327,7 @@ static int rockchip_dp_bind(struct device *dev, struct device *master,
 	dp->plat_data.dev_type = dp->data->chip_type;
 	dp->plat_data.power_on = rockchip_dp_poweron;
 	dp->plat_data.power_off = rockchip_dp_powerdown;
+	dp->plat_data.get_modes = rockchip_dp_get_modes;
 
 	return analogix_dp_bind(dev, dp->drm_dev, &dp->plat_data);
 }