[RFC/PATCH V2] spi: s3c64xx: Enable Word transfer

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This patch enables word transfer for s3c64xx spi driver.
User can set bits_per_word to 32 before calling spi_setup,
which would enable the word transfer mode.

Signed-off-by: Rajeshwari S Shinde <rajeshwari.s@xxxxxxxxxxx>
---
Chnages in V2:
	- Reduced the call for s3c64xx_spi_config 
 drivers/spi/spi-s3c64xx.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 512b889..d1b0a2b 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -498,6 +498,17 @@ static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
 
+	if(sdd->cur_bpw == 32) {
+		/* For word transfer we need to swap bytes */
+		u32 swapcfg = (S3C64XX_SPI_SWAP_TX_EN | S3C64XX_SPI_SWAP_TX_BYTE |
+				S3C64XX_SPI_SWAP_TX_HALF_WORD |
+				S3C64XX_SPI_SWAP_RX_EN |
+				S3C64XX_SPI_SWAP_RX_BYTE |
+				S3C64XX_SPI_SWAP_RX_HALF_WORD);
+		writel(swapcfg, regs + S3C64XX_SPI_SWAP_CFG);
+	} else
+		writel(0, regs + S3C64XX_SPI_SWAP_CFG);
+
 	if (dma_mode) {
 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
 	} else {
@@ -905,13 +916,12 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
 		bpw = xfer->bits_per_word;
 		speed = xfer->speed_hz ? : spi->max_speed_hz;
 
-		if (xfer->len % (bpw / 8)) {
-			dev_err(&spi->dev,
-				"Xfer length(%u) not a multiple of word size(%u)\n",
-				xfer->len, bpw / 8);
-			status = -EIO;
-			goto out;
-		}
+		/*
+		 * Enable byte tranfer if transfer length not a multiple of
+		 * word size
+		 */
+		if (xfer->len % (bpw / 8))
+			bpw = 8;
 
 		if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
 			sdd->cur_bpw = bpw;
-- 
1.7.12.4

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