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

[Nuno Sá]

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
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...

- Nuno Sá