[PATCH 2/2] drm/rockchip: dw_hdmi_qp: expose "overscan" property

[Alexey Charkov <alchark@flipper.net>]

Expose the "overscan" connector property as recognized by KWin and the
likes to compensate for TV overscan cropping.

The CRTC will use the margin values derived from this overscan percentage
in its post-composition scaler to add appropriate blank margins on all
sides of the output image so that the TV doesn't eat up visible content.

Signed-off-by: Alexey Charkov <alchark@flipper.net>
---
 drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
index f35484715c2d..fae44d11dbef 100644
--- a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
@@ -137,10 +137,18 @@ dw_hdmi_qp_rockchip_encoder_atomic_check(struct drm_encoder *encoder,
 					 struct drm_connector_state *conn_state)
 {
 	struct rockchip_hdmi_qp *hdmi = to_rockchip_hdmi_qp(encoder);
+	const struct drm_display_mode *adj_mode = &crtc_state->adjusted_mode;
 	struct rockchip_crtc_state *s = to_rockchip_crtc_state(crtc_state);
 	union phy_configure_opts phy_cfg = {};
+	unsigned int overscan;
 	int ret;
 
+	overscan = min(conn_state->tv.overscan, 100u);
+	s->tv_margins.left   = adj_mode->hdisplay * overscan / 200;
+	s->tv_margins.right  = s->tv_margins.left;
+	s->tv_margins.top    = adj_mode->vdisplay * overscan / 200;
+	s->tv_margins.bottom = s->tv_margins.top;
+
 	if (hdmi->tmds_char_rate == conn_state->hdmi.tmds_char_rate &&
 	    s->output_bpc == conn_state->hdmi.output_bpc)
 		return 0;
@@ -603,6 +611,14 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
 		return dev_err_probe(hdmi->dev, PTR_ERR(connector),
 				     "Failed to init bridge connector\n");
 
+	ret = drm_mode_create_tv_properties_legacy(drm, 0, NULL);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to create TV connector properties\n");
+
+	drm_object_attach_property(&connector->base,
+				   drm->mode_config.tv_overscan_property, 0);
+
 	return 0;
 }
 

-- 
2.52.0