[PATCH 3/3] drm/vc4: Attach underscan props to the HDMI connector

[Daniel Vetter]

On Mon, May 07, 2018 at 04:44:34PM +0200, Boris Brezillon wrote:
> Now that the plane code takes the underscan setup into account, we can
> safely attach the underscan props to the HDMI connector.
> 
> We also take care of filling AVI infoframes correctly to expose the
> top/botton/left/right bar.
> 
> Note that these underscan props match pretty well the
> overscan_{left,right,top,bottom} properties defined in config.txt and
> parsed by the VC4 firmware.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon at bootlin.com>
> ---
>  drivers/gpu/drm/vc4/vc4_hdmi.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 1a6db291d48b..17464b5981f9 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -323,6 +323,16 @@ static struct drm_connector *vc4_hdmi_connector_init(struct drm_device *dev,
>  			   DRM_MODE_CONNECTOR_HDMIA);
>  	drm_connector_helper_add(connector, &vc4_hdmi_connector_helper_funcs);
>  
> +	/* The hborder and vborder limit is arbitrarily set to 1024 which
> +	 * should be more than enough for real use cases. Note that the actual
> +	 * limitation comes from the display mode:
> +	 *	hborder < hdisplay && vborder < vdisplay
> +	 */
> +	drm_connector_attach_underscan_properties(connector,

We should probably sprinkle __must_check over all these :-)
-Daniel

> +						  BIT(DRM_UNDERSCAN_OFF) |
> +						  BIT(DRM_UNDERSCAN_ON),
> +						  1024, 1024);
> +
>  	connector->polled = (DRM_CONNECTOR_POLL_CONNECT |
>  			     DRM_CONNECTOR_POLL_DISCONNECT);
>  
> @@ -408,6 +418,9 @@ static void vc4_hdmi_write_infoframe(struct drm_encoder *encoder,
>  static void vc4_hdmi_set_avi_infoframe(struct drm_encoder *encoder)
>  {
>  	struct vc4_hdmi_encoder *vc4_encoder = to_vc4_hdmi_encoder(encoder);
> +	struct vc4_dev *vc4 = encoder->dev->dev_private;
> +	struct vc4_hdmi *hdmi = vc4->hdmi;
> +	struct drm_connector_state *cstate = hdmi->connector->state;
>  	struct drm_crtc *crtc = encoder->crtc;
>  	const struct drm_display_mode *mode = &crtc->state->adjusted_mode;
>  	union hdmi_infoframe frame;
> @@ -426,6 +439,18 @@ static void vc4_hdmi_set_avi_infoframe(struct drm_encoder *encoder)
>  					   vc4_encoder->rgb_range_selectable,
>  					   false);
>  
> +	if (cstate->underscan.mode == DRM_UNDERSCAN_ON) {
> +		if (cstate->underscan.hborder) {
> +			frame.avi.right_bar = cstate->underscan.hborder / 2;
> +			frame.avi.left_bar = frame.avi.right_bar;
> +		}
> +
> +		if (cstate->underscan.vborder) {
> +			frame.avi.top_bar = cstate->underscan.vborder / 2;
> +			frame.avi.bottom_bar = frame.avi.top_bar;
> +		}
> +	}
> +
>  	vc4_hdmi_write_infoframe(encoder, &frame);
>  }
>  
> -- 
> 2.14.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch