[PATCH v3 1/3] arm64: dts: r8a7795: Add support for R-Car H3 ES2.0

[Geert Uytterhoeven]

Hi Simon,

On Fri, May 12, 2017 at 9:32 AM, Simon Horman <horms at verge.net.au> wrote:
> On Thu, May 11, 2017 at 05:42:27PM +0200, Geert Uytterhoeven wrote:
>> On Thu, May 11, 2017 at 4:53 PM, Simon Horman <horms at verge.net.au> wrote:
>> > On Thu, May 11, 2017 at 01:58:52PM +0200, 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
>> >>     "compatible" and "vsps" properties from the DU node until the driver
>> >>     can handle this.
>> >>
>> >> Move support for the ES1.x revision of the R-Car H3 SoC into a
>> >> separate file.  To avoid duplication, r8a7795-es1.dtsi includes
>> >> r8a7795.dtsi, add adds/removes/overrides device nodes and properties
>> >> where needed.
>> >
>> > I think the above should be re-worded given your explanation below the
>> > scissors that no deletion or overriding occurs.
>>
>> I wanted to document clearly what needs to be done in the generic case...
>> I agree no removal or override is done right now.
>>
>> If you prefer it that way, I can reword it.
>
> I think I would prefer that.
>
>> >> Switch r8a7795-salvator-x.dts and r8a7795-h3ulcb.dts from r8a7795.dtsi
>> >> to r8a7795-es1.dtsi to preserve compatibility.
>> >>
>> >> Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
>> >> ---
>> >> While currently r8a7795-es1.dtsi only adds device nodes, removal of
>> >> devices nodes and properties can be implemented using the /delete-node/
>> >> and /delete-property/ keywords, as shown below:
>> >>
>> >>       &soc {
>> >>               /delete-node/ <name>@<addr>;
>> >>       };
>> >>
>> >>       &<label> {
>> >>               /delete-property/ <prop>;
>> >>       };
>> >
>> > I would be interested to also see an example of an override and
>> > for the examples to be included in the changelog itself.
>>
>> You mean above the scissors? ;-)
>
> Yes, that is what I meant.
>
>> Currently we don't have any devices or properties in DT that need removals
>> or overrides. Note that I did test those.
>>
>> If we add the "vsps" property to the DU node for ES2.0, we can have an
>> override for it now.  But we've plenty of experience with letting .dts
>> override properties in .dtsi.
>
> Ok, point taken.
>
>> For node deletion, we'll have to wait until someone enables the extra USB
>> channels on ES2.0.
>>
>> For property deletion, I don't have an actual example in mind, but I wanted
>> to be sure that worked in case we ever need it.
>
> I appreciate you taking the time to test deletion.
> I think its worth documenting above the scissors.

Will update in v4. I''l have to rebase anyway.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds