spi: tegra114: add SPI_LSB_FIRST support

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>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-tegra114.c

@@ -696,6 +696,11 @@ 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);
@@ -1047,7 +1052,7 @@ 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;