Re: [RFR 2/2] drm/panel: Add simple panel support

Hi Tomi,

On Thursday 17 October 2013 14:35:49 Tomi Valkeinen wrote:

On 17/10/13 14:02, Laurent Pinchart wrote:

quoted

quoted

Okay, so if I understand correctly, translating those bindings to panel

nodes would look somewhat like this:
	dc: display-controller {
		ports {
			port@0 {
				remote-endpoint = <&panel>;
			};
		};
	};
	
	panel: panel {
		ports {
			port@0 {
				remote-endpoint = <&dc>;
			};
		};
	};

The above leaves out any of the other, non-relevant properties. Does
that sound about right?

Yes it does.

It does?

Shouldn't it be something like:

panel {
	ports {
		port@0 {
			endpoint@0 {
				remote = <&dc>;
			};
		};
	};
};

And simplified:

panel {
	port {
		endpoint@0 {
			remote = <&dc>;
		};
	};
};

You do need a node for the endpoint, a remote-endpoint property is not
enough.

My bad, you'r absolutely right. More sleep is needed.

(And while we're at it, the remote-endpoint properties must point to an 
endpoint, not the device DT node.

quoted

Please note that, when a device has as single port, the ports node can be
omitted, and the port doesn't need to be numbered. You would then end up
with> 
 	dc: display-controller {
		port {
			remote-endpoint = <&panel>;
 		};
 	};
 	
 	panel: panel {
 		port {
 			remote-endpoint = <&dc>;
 		};
 	};

I don't think there's a way to simplify it further.

I'm not sure if there's a specific need for the port or endpoint nodes
in cases like the above. Even if we have common properties describing
the endpoint, I guess they could just be in the parent node.

panel {
	remote = <&dc>;
	common-video-property = <asd>;
};

The above would imply one port and one endpoint. Would that work? If we
had a function like parse_endpoint(node), we could just point it to
either a real endpoint node, or to the device's node.

You reference the display controller here, not a specific display controller 
output. Don't most display controllers have several outputs ?

-- 
Regards,

Laurent Pinchart