spi: sirf: add fifo reset/start for cmd transfer

for command mode spi transfer, HW spec requires to do fifo reset work to
clear FIFO status.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/spi/spi-sirf.c b/drivers/spi/spi-sirf.c
index 1a5161336730..6f0602fd7401 100644
--- a/drivers/spi/spi-sirf.c
+++ b/drivers/spi/spi-sirf.c
@@ -312,6 +312,8 @@ static int spi_sirfsoc_cmd_transfer(struct spi_device *spi,
         u32 cmd;
 
         sspi = spi_master_get_devdata(spi->master);
+        writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
+        writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
         memcpy(&cmd, sspi->tx, t->len);
         if (sspi->word_width == 1 && !(spi->mode & SPI_LSB_FIRST))
                 cmd = cpu_to_be32(cmd) >>