spi: dw: fix potential variable assignment error

Commit Message

shaftarger Dec. 7, 2018, 3:28 a.m. UTC

spi::mode is defined by framework for several SPI capabilities,
such as polarity, phase, bit-endian, wire number. Directly use this
variable for setting controller's polarity and phase causes other
bit in register being set. Since SPI framework has its definition,
fetch required bit in spi::mode and set to register.
---
 drivers/spi/spi-dw.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index b705f2bdb8b9..c1b0ae5698ba 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -317,7 +317,8 @@  static int dw_spi_transfer_one(struct spi_controller *master,
 	/* Default SPI mode is SCPOL = 0, SCPH = 0 */
 	cr0 = (transfer->bits_per_word - 1)
 		| (chip->type << SPI_FRF_OFFSET)
-		| (spi->mode << SPI_MODE_OFFSET)
+		| ((((spi->mode & SPI_CPOL)?1:0) << SPI_SCOL_OFFSET) |
+			(((spi->mode & SPI_CPHA)?1:0) << SPI_SCPH_OFFSET))
 		| (chip->tmode << SPI_TMOD_OFFSET);
 
 	/*