Messages in this thread | | | Date | Thu, 27 Feb 2014 09:59:42 +0100 | Subject | Re: [PATCH v2 1/4] spi: spidev: Restore all SPI mode flags on ioctl failure | From | Geert Uytterhoeven <> |
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Hi Mark,
On Thu, Feb 27, 2014 at 5:50 AM, Mark Brown <broonie@kernel.org> 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@linux-m68k.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
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