Re: [PATCH v2 1/2] spi: dt-bindings: spi-controller: Fix #address-cells for slave mode

[Rob Herring <robh+dt@xxxxxxxxxx>]

On Tue, Mar 3, 2020 at 3:45 AM Geert Uytterhoeven
<geert+renesas@xxxxxxxxx> wrote:
>
> Currently, the DT bindings for an SPI controller specify that
> "#address-cells" must be fixed to one.  However, that applies to an SPI
> controller in master mode only.  When running in SPI slave mode,
> "#address-cells" should be zero.
>
> Fix this making the value of "#address-cells" dependent on the presence
> of "spi-slave".
>
> Fixes: 0a1b929356830257 ("spi: Add YAML schemas for the generic SPI options")
> Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> v2:
>   - Use "enum: [0, 1]" instead of min/max limit,
>   - use "- spi-slave" instead of "[ spi-slave ]".
>
> As of dtc commit 403cc79f06a135ae ("checks: Update SPI bus check for
> 'spi-slave'") and Linux commit c2e7075ca8303631 ("scripts/dtc: Update to
> upstream version v1.4.7-57-gf267e674d145"), dtc knows about SPI slave.
>
> However, when using "#address-cells = <0>" with W=1:
>
>     Warning (avoid_unnecessary_addr_size): /soc/spi@e6e10000: unnecessary #address-cells/#size-cells without "ranges" or child "reg" property

What was the point in having #address-cells in the first place for
slaves? Seems like we should make it mutually exclusive with
'spi-slave'.

Rob