| Message ID | 20180717143154.28241-4-maxime.chevallier@bootlin.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 17, 2018 at 04:31:52PM +0200, Maxime Chevallier wrote: > 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> Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de> Sascha > --- > 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 > >
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;
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(-)