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    Subject[PATCH RESEND 3/5] spi: imx: Use correct number of bytes per words
    Date
    The SPI core enforces that we always use the next power-of-two number of
    bytes to store words. As a result, a 24 bits word will be stored in 4
    bytes.

    This commit fixes the spi_imx_bytes_per_word function to return the
    correct number of bytes.

    This also allows to get rid of unnecessary checks in the can_dma
    function, since the SPI core validates that we always have a transfer
    length that is a multiple of the number of bytes per word.

    Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
    ---
    drivers/spi/spi-imx.c | 10 ++++++----
    1 file changed, 6 insertions(+), 4 deletions(-)

    diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
    index ecafbda5ec94..3ae706dac660 100644
    --- a/drivers/spi/spi-imx.c
    +++ b/drivers/spi/spi-imx.c
    @@ -202,7 +202,12 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin,

    static int spi_imx_bytes_per_word(const int bits_per_word)
    {
    - return DIV_ROUND_UP(bits_per_word, BITS_PER_BYTE);
    + if (bits_per_word <= 8)
    + return 1;
    + else if (bits_per_word <= 16)
    + return 2;
    + else
    + return 4;
    }

    static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
    @@ -219,9 +224,6 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,

    bytes_per_word = spi_imx_bytes_per_word(transfer->bits_per_word);

    - if (bytes_per_word != 1 && bytes_per_word != 2 && bytes_per_word != 4)
    - return false;
    -
    for (i = spi_imx->devtype_data->fifo_size / 2; i > 0; i--) {
    if (!(transfer->len % (i * bytes_per_word)))
    break;
    --
    2.11.0
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