From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: [PATCH v2 1/4] spi: spidev: Restore all SPI mode flags on ioctl failure Date: Thu, 27 Feb 2014 09:59:42 +0100 Message-ID: References: <1393324819-3810-1-git-send-email-geert@linux-m68k.org> <20140227045032.GN9383@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: linux-spi , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Geert Uytterhoeven To: Mark Brown Return-path: In-Reply-To: <20140227045032.GN9383-GFdadSzt00ze9xe1eoZjHA@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Hi Mark, On Thu, Feb 27, 2014 at 5:50 AM, Mark Brown wrote: > > In commit f477b7fb13df2b843997559ff34e87d054ba6538 ("spi: DUAL and QUAD > > support"), spi_device.mode was enlarged from 8 to 16 bits. > > Applied, thanks. Thanks a lot! >> For SPI_IOC_WR_MODE this is probably not so important, as it doesn't allow >> setting Quad or Dual mode anyway, but SPI_IOC_WR_LSB_FIRST is used to just >> set or clear a single bit. > > Since there's no API for it at present I'd not expect somethng that is > using spidev to be able to have enabled any of the high mode bits. > Unless I'm missing some path for this? No, you're right. While Quad mode could have been enabled in board info or DT, you can't use it without setting [rt]x_nbits, and you can't share an SPI slave between spidev and another driver[*]. I forgot about the latter. [*] It would be a nice feature for debugging, though. In fact I'm doing it, as the RSPI driver currently ignores the chip select number, so I have 3 m25p80 drivers (in single, dual, resp. quad mode), and an spidev driver, all talking to the same SPI FLASH. 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 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html