Hi Geert-san,
> From: Geert Uytterhoeven, Sent: Tuesday, September 8, 2020 4:12 PM
>
> Hi Shimoda-san,
>
> 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?
Best regards,
Yoshihiro Shimoda
