drm/radeon: add properties to configure the width of the underscan borders

This allows for a more exact fitting on the physical
display. The new properties default to zero which corresponds to the
previous underscan border width[height] formula:
(display_width[display_width] >> 5) + 16.

Example to set a horizontal border width of 30 and a vertikal border
height of 22:

   xrandr --output HDMI-0 --set underscan on --set "underscan hborder" 30 --set "underscan vborder" 22
Signed-off-by: Marius Gröger <marius.groeger@googlemail.com>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_connectors.c

@@ -326,6 +326,34 @@ int radeon_connector_set_property(struct drm_connector *connector, struct drm_pr
 		}
 	}
 
+	if (property == rdev->mode_info.underscan_hborder_property) {
+		/* need to find digital encoder on connector */
+		encoder = radeon_find_encoder(connector, DRM_MODE_ENCODER_TMDS);
+		if (!encoder)
+			return 0;
+
+		radeon_encoder = to_radeon_encoder(encoder);
+
+		if (radeon_encoder->underscan_hborder != val) {
+			radeon_encoder->underscan_hborder = val;
+			radeon_property_change_mode(&radeon_encoder->base);
+		}
+	}
+
+	if (property == rdev->mode_info.underscan_vborder_property) {
+		/* need to find digital encoder on connector */
+		encoder = radeon_find_encoder(connector, DRM_MODE_ENCODER_TMDS);
+		if (!encoder)
+			return 0;
+
+		radeon_encoder = to_radeon_encoder(encoder);
+
+		if (radeon_encoder->underscan_vborder != val) {
+			radeon_encoder->underscan_vborder = val;
+			radeon_property_change_mode(&radeon_encoder->base);
+		}
+	}
+
 	if (property == rdev->mode_info.tv_std_property) {
 		encoder = radeon_find_encoder(connector, DRM_MODE_ENCODER_TVDAC);
 		if (!encoder) {
@@ -1153,10 +1181,17 @@ radeon_add_atom_connector(struct drm_device *dev,
 		drm_connector_attach_property(&radeon_connector->base,
 					      rdev->mode_info.coherent_mode_property,
 					      1);
-		if (ASIC_IS_AVIVO(rdev))
+		if (ASIC_IS_AVIVO(rdev)) {
 			drm_connector_attach_property(&radeon_connector->base,
 						      rdev->mode_info.underscan_property,
 						      UNDERSCAN_AUTO);
+			drm_connector_attach_property(&radeon_connector->base,
+						      rdev->mode_info.underscan_hborder_property,
+						      0);
+			drm_connector_attach_property(&radeon_connector->base,
+						      rdev->mode_info.underscan_vborder_property,
+						      0);
+		}
 		if (connector_type == DRM_MODE_CONNECTOR_DVII) {
 			radeon_connector->dac_load_detect = true;
 			drm_connector_attach_property(&radeon_connector->base,
@@ -1181,10 +1216,17 @@ radeon_add_atom_connector(struct drm_device *dev,
 		drm_connector_attach_property(&radeon_connector->base,
 					      rdev->mode_info.coherent_mode_property,
 					      1);
-		if (ASIC_IS_AVIVO(rdev))
+		if (ASIC_IS_AVIVO(rdev)) {
 			drm_connector_attach_property(&radeon_connector->base,
 						      rdev->mode_info.underscan_property,
 						      UNDERSCAN_AUTO);
+			drm_connector_attach_property(&radeon_connector->base,
+						      rdev->mode_info.underscan_hborder_property,
+						      0);
+			drm_connector_attach_property(&radeon_connector->base,
+						      rdev->mode_info.underscan_vborder_property,
+						      0);
+		}
 		subpixel_order = SubPixelHorizontalRGB;
 		break;
 	case DRM_MODE_CONNECTOR_DisplayPort:
@@ -1212,10 +1254,17 @@ radeon_add_atom_connector(struct drm_device *dev,
 		drm_connector_attach_property(&radeon_connector->base,
 					      rdev->mode_info.coherent_mode_property,
 					      1);
-		if (ASIC_IS_AVIVO(rdev))
+		if (ASIC_IS_AVIVO(rdev)) {
 			drm_connector_attach_property(&radeon_connector->base,
 						      rdev->mode_info.underscan_property,
 						      UNDERSCAN_AUTO);
+			drm_connector_attach_property(&radeon_connector->base,
+						      rdev->mode_info.underscan_hborder_property,
+						      0);
+			drm_connector_attach_property(&radeon_connector->base,
+						      rdev->mode_info.underscan_vborder_property,
+						      0);
+		}
 		break;
 	case DRM_MODE_CONNECTOR_SVIDEO:
 	case DRM_MODE_CONNECTOR_Composite:

drivers/gpu/drm/radeon/radeon_display.c

@@ -1002,6 +1002,24 @@ static int radeon_modeset_create_props(struct radeon_device *rdev)
 				      radeon_underscan_enum_list[i].name);
 	}
 
+	rdev->mode_info.underscan_hborder_property =
+		drm_property_create(rdev->ddev,
+					DRM_MODE_PROP_RANGE,
+					"underscan hborder", 2);
+	if (!rdev->mode_info.underscan_hborder_property)
+		return -ENOMEM;
+	rdev->mode_info.underscan_hborder_property->values[0] = 0;
+	rdev->mode_info.underscan_hborder_property->values[1] = 128;
+
+	rdev->mode_info.underscan_vborder_property =
+		drm_property_create(rdev->ddev,
+					DRM_MODE_PROP_RANGE,
+					"underscan vborder", 2);
+	if (!rdev->mode_info.underscan_vborder_property)
+		return -ENOMEM;
+	rdev->mode_info.underscan_vborder_property->values[0] = 0;
+	rdev->mode_info.underscan_vborder_property->values[1] = 128;
+
 	return 0;
 }
 
@@ -1159,8 +1177,14 @@ bool radeon_crtc_scaling_mode_fixup(struct drm_crtc *crtc,
 			     ((radeon_encoder->underscan_type == UNDERSCAN_AUTO) &&
 			      drm_detect_hdmi_monitor(radeon_connector->edid) &&
 			      is_hdtv_mode(mode)))) {
-				radeon_crtc->h_border = (mode->hdisplay >> 5) + 16;
-				radeon_crtc->v_border = (mode->vdisplay >> 5) + 16;
+				if (radeon_encoder->underscan_hborder != 0)
+					radeon_crtc->h_border = radeon_encoder->underscan_hborder;
+				else
+					radeon_crtc->h_border = (mode->hdisplay >> 5) + 16;
+				if (radeon_encoder->underscan_vborder != 0)
+					radeon_crtc->v_border = radeon_encoder->underscan_vborder;
+				else
+					radeon_crtc->v_border = (mode->vdisplay >> 5) + 16;
 				radeon_crtc->rmx_type = RMX_FULL;
 				src_v = crtc->mode.vdisplay;
 				dst_v = crtc->mode.vdisplay - (radeon_crtc->v_border * 2);

drivers/gpu/drm/radeon/radeon_mode.h

@@ -241,6 +241,8 @@ struct radeon_mode_info {
 	struct drm_property *tmds_pll_property;
 	/* underscan */
 	struct drm_property *underscan_property;
+	struct drm_property *underscan_hborder_property;
+	struct drm_property *underscan_vborder_property;
 	/* hardcoded DFP edid from BIOS */
 	struct edid *bios_hardcoded_edid;
 
@@ -370,6 +372,8 @@ struct radeon_encoder {
 	uint32_t pixel_clock;
 	enum radeon_rmx_type rmx_type;
 	enum radeon_underscan_type underscan_type;
+	uint32_t underscan_hborder;
+	uint32_t underscan_vborder;
 	struct drm_display_mode native_mode;
 	void *enc_priv;
 	int audio_polling_active;