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    SubjectRe: [PATCH] [drivers] [SPI] SPI_GPIO: add support for controllers with missing MISO pin
    On Thursday 25 June 2009, Marek Szyprowski wrote:
    > > Thing is, this raises two related issues:  (a) there's the
    > > analagous input-only case where MOSI isn't used, e.g. for
    > > some kinds of sensor; and (b) there's also "real 3-wire SPI"
    > > (spi->mode & SPI_3WIRE) where interactions are limited to
    > > half duplex and one pin switches roles between MOSI and MISO.
    > >
    > > Clearly this "output-only" case is a subset of SPI_3WIRE (the
    > > MOMI/SISO pin can't switch direction) so one more change I
    > > want to see is requiring that spi->mode flag be set in all
    > > SPI devices registered when this mode is used.

    Don't forget that change ...

    > > If you have time, it would be good to generalize this patch
    > > to cover all of those 3-wire modes ... accept all half
    > > duplex calls, use gpio_direction_*() to switch direction.
    > >
    > > If not -- e.g. nothing to test that with! -- then I can
    > > understand, but please make your changes with that model
    > > in mind, and leave an appropriate FIXME in place.
    > I'm sorry, but I have only a hw board with missing MISO pin so I won't
    > be able to properly check/debug any other configurations.

    OK, then just stick to what you can test, and comment the issue.

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      Last update: 2009-06-25 17:39    [W:0.023 / U:27.824 seconds]
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