This patch enables word transfer for s3c64xx spi driver.
User can set bits_per_word to 32 or 16 or 8, before calling
spi_setup, which would enable the corresponding transfer mode.
Change-Id: Ib04f9851a3ea891d2bfa527f2100acd314fe1c98
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.
Chnages in V4:
- Add switch case to support both 16 and 32 bit transfer.
- Corrected checkpatch error.
drivers/spi/spi-s3c64xx.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 512b889..1620b74 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -491,6 +491,7 @@ static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
{
void __iomem *regs = sdd->regs;
u32 modecfg, chcfg;
+ u32 swapcfg = 0;
modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
@@ -498,6 +499,22 @@ static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
+ switch (sdd->cur_bpw) {
+ case 32:
+ swapcfg = S3C64XX_SPI_SWAP_TX_HALF_WORD |
+ S3C64XX_SPI_SWAP_RX_HALF_WORD;
+ case 16:
+ swapcfg |= S3C64XX_SPI_SWAP_TX_EN |
+ S3C64XX_SPI_SWAP_RX_EN |
+ S3C64XX_SPI_SWAP_RX_BYTE |
+ S3C64XX_SPI_SWAP_TX_BYTE;
+ writel(swapcfg, regs + S3C64XX_SPI_SWAP_CFG);
+ break;
+ default:
+ writel(0, regs + S3C64XX_SPI_SWAP_CFG);
+ break;
+ }
+
if (dma_mode) {
chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
} else {
@@ -905,13 +922,12 @@ 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
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
