Some SPI devices expects SPI transfers to be in Least significant byte
first order and some devices expect Most significant byte first order.

This patch adds SPI_LSBYTE_FIRST to the supported SPI mode list and also
configures Tegra SPI controller accordingly.

Signed-off-by: Sowjanya Komatineni <skomatin...@nvidia.com>
---
 drivers/spi/spi-tegra114.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c
index 212bb90aa0cb..d3b95bba2361 100644
--- a/drivers/spi/spi-tegra114.c
+++ b/drivers/spi/spi-tegra114.c
@@ -755,6 +755,11 @@ static u32 tegra_spi_setup_transfer_one(struct spi_device 
*spi,
                else
                        command1 &= ~SPI_LSBIT_FE;
 
+               if (spi->mode & SPI_LSBYTE_FIRST)
+                       command1 |= SPI_LSBYTE_FE;
+               else
+                       command1 &= ~SPI_LSBYTE_FE;
+
                if (spi->mode & SPI_3WIRE)
                        command1 |= SPI_BIDIROE;
                else
@@ -1164,7 +1169,8 @@ static int tegra_spi_probe(struct platform_device *pdev)
 
        /* the spi->mode bits understood by this driver: */
        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST |
-                           SPI_TX_DUAL | SPI_RX_DUAL | SPI_3WIRE;
+                           SPI_TX_DUAL | SPI_RX_DUAL | SPI_3WIRE |
+                           SPI_LSBYTE_FIRST;
        master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
        master->setup = tegra_spi_setup;
        master->transfer_one_message = tegra_spi_transfer_one_message;
-- 
2.7.4

Reply via email to