• Mark Brown's avatar
    spi: Provide common spi_message processing loop · b158935f
    Mark Brown authored
    The loops which SPI controller drivers use to process the list of transfers
    in a spi_message are typically very similar and have some error prone areas
    such as the handling of /CS. Help simplify drivers by factoring this code
    out into the core - if drivers provide a transfer_one() function instead
    of a transfer_one_message() function the core will handle processing at the
    message level.
    /CS can be controlled by either setting cs_gpio or providing a set_cs
    function. If this is not possible for hardware reasons then both can be
    omitted and the driver should continue to implement manual /CS handling.
    This is a first step in refactoring and it is expected that there will be
    further enhancements, for example factoring out of the mapping of transfers
    for DMA and the initiation and completion of interrupt driven transfers.
    Signed-off-by: default avatarMark Brown <broonie@linaro.org>
spi.h 3.2 KB