Re: [PATCH 05/13] DT: clock: rcar-gen2-cpg-clocks: document R8A7792 support

Simon Horman
2016-06-01T00:30:16Z

On Wed, Jun 01, 2016 at 09:25:35AM +0900, Simon Horman wrote:
> [Cc: Geert]
>
> On Wed, Jun 01, 2016 at 01:20:11AM +0300, Sergei Shtylyov wrote:
> > Renesas R8A7792 SoC is a member of the R-Car gen2 family and so has CPG...
> >
> > Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>
> Hi Sergei,
>
> I think the prefix of this patch should be "clk: shmobile: rcar-gen2: "
>
> Hi Geert,
>
> I apologise if I have missed a discussion of this topic or if my analysis
> is wrong for some reason but I am curious to know what the intended way
> is for the rcar-gen2 CPG driver to handle differences in the availability
> of clocks across different SoCs.
>
> My possibly naïve expectation is that the implementation would use compat
> strings. But as it stands it appears that all clocks supported by the
> driver are available for all SoCs. This does not seem to reflect the
> documentation (v2.00).
>
> FWIW my quick analysis of clocks supported by the driver present in
> renesas-drivers-2016-05-31-v4.7-rc1 but not present on one or more SoCs
> is as follows:
>
> Not present on V2H: sdh, sd0
> Not present on V2H or E2: sd1
> Not present on H2, M2-W, M2-N, E2: rcan

Thinking about a little more, which I obviously should have done
before hitting send:

There does not seem to be any conflict in the implementation of individual
clocks between SoCs at least so far as clocks supported by the driver goes.
Its just that some of them aren't present on all SoCs. But in that case
they shouldn't be used in DT: the DT describes the HW. So I think I'm ok
with this patch. Sorry for the noise!

Acked-by: Simon Horman <horms+renesas@verge.net.au>

> > ---
> > Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > Index: renesas/Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt
> > ===================================================================
> > --- renesas.orig/Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt
> > +++ renesas/Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt
> > @@ -10,6 +10,7 @@ Required Properties:
> > - compatible: Must be one of
> > - "renesas,r8a7790-cpg-clocks" for the r8a7790 CPG
> > - "renesas,r8a7791-cpg-clocks" for the r8a7791 CPG
> > + - "renesas,r8a7792-cpg-clocks" for the r8a7792 CPG
> > - "renesas,r8a7793-cpg-clocks" for the r8a7793 CPG
> > - "renesas,r8a7794-cpg-clocks" for the r8a7794 CPG
> > and "renesas,rcar-gen2-cpg-clocks" as a fallback.
> >
>