Re: [PATCH v3 4/6] spi: spi-axi-spi-engine: Add support for MOSI idle configuration

From: Marcelo Schmitt
Date: Fri Jun 07 2024 - 10:39:29 EST


On 06/07, Nuno Sá wrote:
> On Thu, 2024-06-06 at 18:31 -0300, Marcelo Schmitt wrote:
>
> ...
>
> >
> >
> >
> > When is a driver version check needed?
> > Yes, older versions of SPI-Engine won't support this, but the patch set should
> > cause no regression. Even if loading the current ad4000 driver with
> > older SPI-Engine HDL and driver, the ADC driver would get a warn (or error?)
> > and do what's possible without MOSI idle feature (probably only be able to do
> > reg access) or fail probing.
> >
>
> Maybe I'm missing something but with the patchset we unconditionally set
> SPI_MOSI_IDLE_HIGH. So if we load an hdl which does not support it things will
> apparently be ok but it won't actually work, right? If I'm right we should have
Yes, that's correct.

> a bit in a RO config_register telling us that the feature is being supported or
> not. That way we only set the mode bit if we do support it...

Ok, understood. Will do it for v4.

Thanks,
Marcelo

>
> - Nuno Sá
>
>