Re: [PATCH v10 3/3] dt-bindings: mfd: Document Renesas R-Car Gen3 RPC-IF controller bindings
From: Sergei Shtylyov
Date: Fri Apr 19 2019 - 14:28:23 EST
On 04/18/2019 07:55 PM, Sergei Shtylyov wrote:
>>>> > > Document the bindings used by the Renesas R-Car Gen3 RPC-IF
>>> MFD controller.
>>>> > >
>>>> > > Signed-off-by: Mason Yang <masonccyang@xxxxxxxxxxx>
>>>> > > ---
>>>> > > .../devicetree/bindings/mfd/mfd-renesas-rpc.txt | 37 +++++++++
>>>> > +++++++++++++
>>>> > > 1 file changed, 37 insertions(+)
>>>> > > create mode 100644 Documentation/devicetree/bindings/mfd/mfd-
>>>> > renesas-rpc.txt
>>>> > >
>>>> > > diff --git a/Documentation/devicetree/bindings/mfd/mfd-renesas-
>>>> > rpc.txt b/Documentation/devicetree/bindings/mfd/mfd-renesas-rpc.txt
>>>> > > new file mode 100644
>>>> > > index 0000000..bfb3d29
>>>> > > --- /dev/null
>>>> > > +++ b/Documentation/devicetree/bindings/mfd/mfd-renesas-rpc.txt
>>>> > > @@ -0,0 +1,37 @@
>>>> > > +Renesas R-Car Gen3 RPC-IF MFD controller Device Tree Bindings
>>>> > > +-------------------------------------------------------------
>>>> > > +
>>>> > > +Required properties:
>>>> > > +- compatible: should be an SoC-specific compatible value, followed by
>>>> > > + "renesas,rcar-gen3-rpc" as a fallback.
>>>> > > + supported SoC-specific values are:
>>>> > > + "renesas,r8a77995-rpc" (R-Car D3)
>>>> > > +- reg: should contain 2 entries, one for the base address of rpc-
>>>> > if registers,
>>>> > > + and one for the direct mapping area
>>>> > > +- reg-names: should contain "regs", and "dirmap"
>>>> >
>>>> > The device tree describes the hardware, not the driver. Why
>>> did you remove
>>>> > the "wbuf" area?
>>>>
>>>> I don't think we should describe the hardware that driver did not
>>> implement it
>>>> because there are still many RPC registers we don't use them.
>>>
>>> I have to repeat: we describe the hardware, not the driver capabilities.
>>
>> how about:
>>
>> - reg: should contain three register areas:
>> first for the base address of rpc-if registers,
>> second for the direct mapping read mode and
>> third for an optional write buffer area.
>> - reg-names: should contain "regs", "dirmap" and "wbuf"(optional).
>>
>> is it OK ?
>
> No, the write buffer area is always there, at least on the gen3 chips.
> (I forgot which other Renesas SoC has RPC-IF as well).
So it was RZ/A1. But it didn't have the HyperFlash mode...
>> thanks & best regards,
>> Mason
MBR, Sergei