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Subject[PATCH V1 12/26] spi: tegra114: add SPI_LSB_FIRST support
Date
Tegra SPI controller supports lsb first mode. Default is MSB bit first
and on selection of SPI_LSB_FIRST through SPI mode transmission happens
with LSB bit first.

This patch adds SPI_LSB_FIRST flag to mode_bits and also configures it
on request.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
drivers/spi/spi-tegra114.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c
index 0e228f1e910e..d39f7b05b824 100644
--- a/drivers/spi/spi-tegra114.c
+++ b/drivers/spi/spi-tegra114.c
@@ -750,6 +750,11 @@ static u32 tegra_spi_setup_transfer_one(struct spi_device *spi,
else if (req_mode == SPI_MODE_3)
command1 |= SPI_CONTROL_MODE_3;

+ if (spi->mode & SPI_LSB_FIRST)
+ command1 |= SPI_LSBIT_FE;
+ else
+ command1 &= ~SPI_LSBIT_FE;
+
if (tspi->cs_control) {
if (tspi->cs_control != spi)
tegra_spi_writel(tspi, command1, SPI_COMMAND1);
@@ -1137,7 +1142,7 @@ static int tegra_spi_probe(struct platform_device *pdev)
master->max_speed_hz = 25000000; /* 25MHz */

/* the spi->mode bits understood by this driver: */
- master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
master->setup = tegra_spi_setup;
master->transfer_one_message = tegra_spi_transfer_one_message;
master->num_chipselect = MAX_CHIP_SELECT;
--
2.7.4
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