RE: [PATCH 1/2] spi: renesas,rzv2m-csi: Add SPI Slave related properties

From: Fabrizio Castro
Date: Wed Sep 27 2023 - 06:19:10 EST


Hi Mark,

Thanks for your reply!

> From: Mark Brown <broonie@xxxxxxxxxx>
> Subject: Re: [PATCH 1/2] spi: renesas,rzv2m-csi: Add SPI Slave related
> properties
>
> On Wed, Sep 27, 2023 at 11:44:17AM +0200, Geert Uytterhoeven wrote:
> > On Wed, Sep 27, 2023 at 11:21 AM Mark Brown <broonie@xxxxxxxxxx>
> wrote:
>
> > > I see. Is there any control over what the chip select is when
> there is
> > > one, in which case we could just look to see if there's one
> specified?
>
> > On RZ/V2M there isn't, as there is only a single hardware chip
> select.
>
> > On MSIOF, there are 3 hardware chip selects, but apparently only the
> > primary one can be used in target mode.
>
> OK, it sounds like we do need a property then. Like I say I'd rather
> not have one that just works for _NO_CS in order to avoid confusion
> for
> people writing SPI device drivers, either something in the generic
> target binding or a device specific one.

Shall I invert the logic then? What I mean is I could drop property
"renesas,csi-ss" and add property "renesas,csi-no-ss" instead, therefore
without "renesas,csi-no-ss" pin SS will be used, with "renesas,csi-no-ss"
pin SS won't be used.
What do you think?

Also, I could drop "renesas,csi-ss-high" and use "spi-cs-high" instead?

Geert, any thoughts on the above?

Thanks,
Fab