Hi Geert, On Thursday 20 Apr 2017 11:36:59 Geert Uytterhoeven wrote: > On Mon, Mar 27, 2017 at 10:48 AM, Laurent Pinchart wrote: > > On Friday 24 Mar 2017 14:37:44 Geert Uytterhoeven wrote: > >> Update r8a7795.dtsi so it corresponds to R-Car H3 ES2.0 or later: > >> - The following devices no longer exist on ES2.0, and are thus removed: > >> fcpf2, fcpvd3, fcpvi2, fdp1-2, usb3-if1, vspd3, vspi2. > >> > >> - The DU <-> VSPD topology is different on ES2.0, hence remove the > >> "vsps" property from the DU node until the driver can handle this. > > > > I think I'll need a different compatible string between ES1.x and ES2 for > > the DU. It could make sense to move the whole DU node to *-es1.dtsi. We > > can decide about that later when I'll have a DU driver prototype ready. > > Why would you need a different compatible string? > Can't you use soc_device_match() to handle ES1.x SoCs? > > The different DU <-> VSPD topology is handled through the vsps property in > DTS. Are the ports different, too? That can be handled in DTS. My point (not expressed clearly) was that, as I'll need a different vsps property, I can as well go for a different compatible string. > The main reason why I kept the DU node in r8a7795.dtsi is that the board DTS > refers to it. Sharing board DTS means there needs to be at least a > placeholder node for the DU in r8a7795.dtsi, unless you want to keep on > shuffling board overrides around. As the ports are identical it makes sense to share the same board DTS, I agree with you. We could override the compatible string in r8a7795-es1.dtsi and leave it blank in r8a7795.dtsi for now, as there's no driver support for ES2.0. That's a bit of a workaround as it shouldn't matter to DT whether driver support is available or not. On the other hand, leaving the vsps property out is a workaround too. The current driver will fail probing if the number of VSPs is different than the number of CRTCs, so I believe you can keep the vsps property in r8a7795.dtsi with 3 VSPS without causing any problem. However, there's no DT bindings for the H3 ES2.0 DU yet, so we would end up merging DT without bindings, which is not good. I think that regardless of how we proceed, keeping the DU node in the ES2.0 .dtsi will be a violation of that policy. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
