Re: [PATCH 5/9] dt-bindings: mmc: mmci: add delay block base register for sdmmc

[Rob Herring]

On Thu, Jan 16, 2020 at 3:21 AM Ludovic BARRE <ludovic.barre@xxxxxx> wrote:
>
> Hi Rob
>
> Le 1/15/20 Ã 3:56 PM, Rob Herring a Ãcrit :
> > On Fri, Jan 10, 2020 at 02:48:19PM +0100, Ludovic Barre wrote:
> >> To support the sdr104 mode, the sdmmc variant has a
> >> hardware delay block to manage the clock phase when sampling
> >> data received by the card.
> >>
> >> This patch adds a second base register (optional) for
> >> sdmmc delay block.
> >>
> >> Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
> >> ---
> >>   Documentation/devicetree/bindings/mmc/mmci.txt | 2 ++
> >>   1 file changed, 2 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/mmc/mmci.txt b/Documentation/devicetree/bindings/mmc/mmci.txt
> >> index 6d3c626e017d..4ec921e4bf34 100644
> >> --- a/Documentation/devicetree/bindings/mmc/mmci.txt
> >> +++ b/Documentation/devicetree/bindings/mmc/mmci.txt
> >> @@ -28,6 +28,8 @@ specific for ux500 variant:
> >>   - st,sig-pin-fbclk       : feedback clock signal pin used.
> >>
> >>   specific for sdmmc variant:
> >> +- reg                        : a second base register may be defined if a delay
> >> +                           block is present and used for tuning.
> >
> > Which compatibles have a 2nd reg entry?
>
> In fact, mmci driver is ARM Amba driver (arm,primecell) and has only one
> compatible "arm,pl18x".
> The variants are identified by primecell-periphid property
> (discovered at runtime with HW block register or defined by
> device tree property "arm,primecell-periphid").
>
> The defaults "arm,pl18x" variants have only one base register,
> but the SDMMC need a second base register for these
> delay block registers.
>
> example of sdmmc node:
>         sdmmc1: sdmmc@58005000 {
>                 compatible = "arm,pl18x", "arm,primecell";
>                 arm,primecell-periphid = <0x00253180>;
>                 reg = <0x58005000 0x1000>, <0x58006000 0x1000>;
>         };
>
> what do you advise?

I missed that this is a primecell block. Just give some indication
which variants have this 2nd range.

Rob