Re: [PATCHv3 3/5] dt-bindings: misc: ge-achc: Convert to DT schema format

From: Sebastian Reichel
Date: Wed Jun 09 2021 - 11:50:43 EST


Hi,

On Wed, Jun 09, 2021 at 12:47:47PM +0100, Mark Brown wrote:
> On Fri, May 28, 2021 at 01:33:45PM +0200, Sebastian Reichel wrote:
>
> > -Required SPI properties:
> > -
> > -- reg : Should be address of the device chip select within
> > - the controller.
>
> There is an existing binding...
>
> > + reg:
> > + minItems: 2
> > + maxItems: 2
> > + items:
> > + - description: Control interface
> > + - description: Firmware programming interface
>
> ...but this new one is incompatible with it.

The current binding is broken, since it uses the same compatible
value for two different SPI "devices" (main SPI interface and
EzPort). It only "works" because compatible string is only used
to export the device to userspace via spidev and otherwise ignored.

But the main spidev is not used by current FW and FW update cannot
be done from userspace because it requires reset pin handling during
spi transactions. So basically upstream support for this binding is
completley broken anyways (downstream has additional patches to work
around the limitations).

In PATCHv2 it was pointed out, that there should be one device for
both chip selects, since the reset/clocks/... are shared.

-- Sebastian

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