[Letux-kernel] LX16 SPI Display

[Paul Boddie]

On Tuesday, 14 January 2025 17:12:05 CET H. Nikolaus Schaller wrote:
> 
> Ok, I played with spi-cpol and spi-cpha but it seems to have no effect which
> is a little unexpected.

[...]

> Regarding spi-cpol and spi-cpha: do you know if this is generic or if these
> flags have to be handled by the spi-controller driver?

I imagine that the actual driver would need to implement it, at least if the 
hardware is to do all the hard work, and in the X1600 the PHA and POL fields 
in the appropriate control register determine the flavour of SPI being used.

As noted previously, the Waveshare board is weird in the sense that the 
signalling is actually driving a shift register, and then some logic on the 
board presents the contents of the shift register to the LCD controller's 
parallel interface. At least if descriptions of the board that I have read are 
correct.

Paul