spi/ath79: add missing HIGH->LOW SCK transition

The 'ath79_spi_txrx_mode0' function does not
set the SCK signal to LOW at the end of a word
transfer. This causes communications errors with
certain devices (e.g. the PCF2123 RTC chip).

The patch ensures that the SCK signal will be LOW.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/spi/spi-ath79.c b/drivers/spi/spi-ath79.c
index e02528244451..d4b8e1236612 100644
--- a/drivers/spi/spi-ath79.c
+++ b/drivers/spi/spi-ath79.c
@@ -200,6 +200,8 @@ static u32 ath79_spi_txrx_mode0(struct spi_device *spi, unsigned nsecs,
                 ath79_spi_delay(sp, nsecs);
                 ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out | AR71XX_SPI_IOC_CLK);
                 ath79_spi_delay(sp, nsecs);
+                if (bits == 1)
+                        ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out);
 
                 word <<= 1;
         }