Re: [PATCH RFC 1/3] spi: Allow SPI controller override device buswidth

From: Geert Uytterhoeven
Date: Mon Mar 02 2020 - 13:51:46 EST


Hi John,

On Fri, Feb 28, 2020 at 4:23 PM John Garry <john.garry@xxxxxxxxxx> wrote:
> Currently ACPI firmware description for a SPI device does not have any
> method to describe the data buswidth on the board.
>
> So even through the controller and device may support higher modes than
> standard SPI, it cannot be assumed that the board does - as such, that
> device is limited to standard SPI in such a circumstance.
>
> As a workaround, allow the controller driver supply buswidth override bits,
> which are used inform the core code that the controller driver knows the
> buswidth supported on that board for that device.

Just wondering: can't the controller just override this (e.g. in the .setuup()
callback) without having to touch the generic code?

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds