From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: [PATCH RFC 1/3] spi: Allow SPI controller override device buswidth Date: Mon, 2 Mar 2020 19:51:29 +0100 Message-ID: References: <1582903131-160033-1-git-send-email-john.garry@huawei.com> <1582903131-160033-2-git-send-email-john.garry@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: Mark Brown , linux-spi , Linuxarm , Linux Kernel Mailing List , MTD Maling List , Andy Shevchenko To: John Garry Return-path: In-Reply-To: <1582903131-160033-2-git-send-email-john.garry-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Hi John, On Fri, Feb 28, 2020 at 4:23 PM John Garry 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-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org 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