Hi Shimoda-san,
On Tue, Sep 8, 2020 at 10:45 AM Yoshihiro Shimoda
<yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
> > From: Geert Uytterhoeven, Sent: Tuesday, September 8, 2020 4:12 PM
> > On Tue, Sep 8, 2020 at 3:01 AM Yoshihiro Shimoda
> > <yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
> > > > From: Geert Uytterhoeven, Sent: Tuesday, September 8, 2020 12:31 AM
> > > > On Mon, Sep 7, 2020 at 11:20 AM Yoshihiro Shimoda
> > > > <yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
> > > > > Add device tree bindings documentation for Renesas R-Car V3U
> > > > > Falcon CPU and BreakOut boards.
> > > > >
> > > > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > > >
> > > > Thanks for your patch!
> > > >
> > > > > --- a/Documentation/devicetree/bindings/arm/renesas.yaml
> > > > > +++ b/Documentation/devicetree/bindings/arm/renesas.yaml
> > > > > @@ -283,6 +283,9 @@ properties:
> > > > >
> > > > > - description: R-Car V3U (R8A779A0)
> > > > > items:
> > > > > + - enum:
> > > > > + - renesas,falcon-cpu # Falcon CPU board (RTP0RC779A0CPB0010S)
> > > > > + - renesas,falcon-breakout # Falcon BreakOut board (RTP0RC779A0BOB0010S)
> > > > > - const: renesas,r8a779a0
> > > >
> > > > How is this intended to be used?
> > >
> > > I intended to use "renesas,falcon-breakout", "renesas,falcon-cpu", "renesas,r8a779a0"
> > > in the future. However, if so, I should fix the description like Kingfisher.
> > >
> > > > The above means its users should declare either
> > > >
> > > > compatible = "renesas,falcon-cpu", "renesas,r8a779a0";
> > > >
> > > > or
> > > >
> > > > compatible = "renesas,falcon-breakout", "renesas,r8a779a0";
> > >
> > > I understood it. I mistook the description...
> > >
> > > > However, falcon-cpu.dtsi has just
> > > >
> > > > compatible = "renesas,falcon-cpu";
> > > >
> > > > Who will use "renesas,falcon-breakout"?
> > >
> > > I intended to add falcon-breakout.dtsi and the file intended to use
> > > "renesas,falcon-breakout" like Kingfisher + ULCB in the future.
> > >
> > > However, I realized a combination between the cpu board and
> > > the breakout board differs than ULCB + Kingfisher like below:
> > >
> > > - The ULCB without the Kingfisher can work.
> > > -- So, some .dts files exist like r8a77951-ulcb.dts.
> > > -- And, r8a77951-ulcb-kf.dts includes r8a77951-ulcb.dts for ULCB + Kingfisher.
> > >
> > > - The Falcon CPU board without the breakout board cannot work actually.
> > > -- But, on this initial patch series enables the CPU board hardware (memory nodes & SCIF0) only.
> > > -- The breakout board has some hardware like Ethernet and CAN.
> > > -- The breakout board also has some connectors for sub boards.
> > > -- So, I intended to add falcon-breakout.dtsi to support Ethernet in the future.
> > >
> > > In this case, I wonder if we should describe just "renesas,falcon" only
> > > because we will not have r8a779a0-falcon-{cpu,breakout}.dts files.
> > > But, what do you think?
> >
> > What kind of connector does the Falcon CPU board have?
> > Perhaps it can be plugged into another base board, too?
>
> The Falcon CPU board has 2 EXIO connectors. The EXIO connector
> has 400 pins. So, I think it can be plugged into another base board.
>
> > What about modelling it like the iwave,g22m SoM, and the iwave,g22d
> > SODIMM board?
> > arch/arm/boot/dts/r8a7745-iwg*
>
> Thank you for the suggestion. So, I'll fix the patch like below.
> ---
>
> - description: R-Car V3U (R8A779A0)
> items:
> + - enum:
> + - renesas,r8a779a0-cpu # Falcon CPU board (RTP0RC779A0CPB0010S
> + - const: renesas,r8a779a0
> +
> + - items:
> + - enum:
> + - renesas,r8a779a0-breakout # Falcon BreakOut board (RTP0RC779A0BOB0010S)
> + - const: renesas,r8a779a0-cpu
> - const: renesas,r8a779a0
>
> - description: RZ/N1D (R9A06G032)
> ---
>
> And, I will fix the compatible of r8a779a0-falcon.dts in the patch 14/14 like below.
> ---
> + compatible = "renesas,falcon-breakout", "renesas,falcon-cpu", "renesas,r8a779a0";
> ---
>
> But, what do you think?
Thanks, looks good to me.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
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
