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>
---
Changes in V2
- Reduced the call for s3c64xx_spi_config.
Changes in V3:
- Corrected the coding style nits.
drivers/spi/spi-s3c64xx.c | 25 ++++++++++++++++++-------
1 file changed, 18 insertions(+), 7 deletions(-)
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 512b889..cbbeff3 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -498,6 +498,18 @@ 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 +917,12 @@ 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 transfer 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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