[PATCH V2 12/20] spi: tegra114: add support for LSBYTE_FIRST

From: Sowjanya Komatineni
Date: Thu Apr 04 2019 - 20:15:35 EST


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 <skomatineni@xxxxxxxxxx>
---
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