Re: [PATCH] spi: tegra114: initialize native chip selects inactive

[Abraham Zukor <abe@maticrobots.com>]

On 28/07/2026 10:34, Jon Hunter wrote:
> Exactly. That's my point. Which is the right one? The answer is
> probably neither, but whatever is present on the bus.

I think that defaulting to active-low is correct. The Tegra234 SPI
controller hardware defaults to active-low (all bits in CS_POL_INACTIVE
are set) so an active-high device is already asserted before this driver
initializes. I checked the controller drivers under drivers/spi/; they
either default to active-low or preserve the hardware default.

A more complex option is to scan the device tree children, check each
item for whether it uses native chip select (as opposed to GPIO CS) and
check for spi-cs-high. I found no other spi drivers that do this at
probe time, and I don't think it's worth the complexity, but I can send
it as a v2 if needed.

Thanks,
Abe