Re: [PATCH v4 3/3] Documentation: of: Document graph bindings

[Grant Likely]

On Sat, 8 Mar 2014 11:35:38 +0200, Tomi Valkeinen <tomi.valkeinen@xxxxxx> wrote:
> On 07/03/14 20:11, Grant Likely wrote:
> 
> >>> Any board not using that port can just leave the endpoint disconnected.
> >>
> >> Hmm I see. I'm against that.
> >>
> >> I think the SoC dtsi should not contain endpoint node, or even port node
> >> (at least usually). It doesn't know how many endpoints, if any, a
> >> particular board has. That part should be up to the board dts.
> > 
> > Why? We have established precedence for unused devices still being in
> > the tree. I really see no issue with it.
> 
> I'm fine with having ports defined in the SoC dtsi. A port is a physical
> thing, a group of pins, for example.
> 
> But an endpoint is a description of the other end of a link. To me, a
> single endpoint makes no sense, there has to be a pair of endpoints. The
> board may need 0 to n endpoints, and the SoC dtsi cannot know how many
> are needed.
> 
> If the SoC dtsi defines a single endpoint for a port, and the board
> needs to use two endpoints for that port, it gets really messy: one
> endpoint is defined in the SoC dtsi, and used in the board dts. The
> second endpoint for the same port needs to be defined separately in the
> board file. I.e. something like:

Sure. If endpoints are logical, then only create the ones actually
hooked up. No problem there. But nor do I see any issue with having
empty connections if the board author things it makes sense to have them
in the dtsi.

> 
> /* the first ep */
> &port1_ep {
> 	remote-endpoint = <&..>;
> };
> 
> &port1 {
> 	/* the second ep */
> 	endpoint@2 {
> 		remote-endpoint = <&..>;
> 	};
> };
> 
> Versus:
> 
> &port1 {
> 	/* the first ep */
> 	endpoint@1 {
> 		remote-endpoint = <&..>;
> 	};
> 
> 	/* the second ep */
> 	endpoint@2 {
> 		remote-endpoint = <&..>;
> 	};
> };
> 
>  Tomi
> 
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/