spi_mpc83xx: support for lsb-first transfers
This controller supports LSB-first transfers; let drivers use them.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
index e2d8dbc..18c475d 100644
--- a/drivers/spi/spi_mpc83xx.c
+++ b/drivers/spi/spi_mpc83xx.c
@@ -153,13 +153,16 @@
len = len - 1;
/* mask out bits we are going to set */
- regval &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH |
- SPMODE_LEN(0xF) | SPMODE_DIV16 | SPMODE_PM(0xF));
+ regval &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
+ | SPMODE_LEN(0xF) | SPMODE_DIV16
+ | SPMODE_PM(0xF) | SPMODE_REV);
if (spi->mode & SPI_CPHA)
regval |= SPMODE_CP_BEGIN_EDGECLK;
if (spi->mode & SPI_CPOL)
regval |= SPMODE_CI_INACTIVEHIGH;
+ if (!(spi->mode & SPI_LSB_FIRST))
+ regval |= SPMODE_REV;
regval |= SPMODE_LEN(len);
@@ -248,9 +251,11 @@
regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
- /* Mask out bits_per_wordgth */
- regval &= ~SPMODE_LEN(0xF);
+ /* mask out bits we are going to set */
+ regval &= ~(SPMODE_LEN(0xF) | SPMODE_REV);
regval |= SPMODE_LEN(bits_per_word);
+ if (!(spi->mode & SPI_LSB_FIRST))
+ regval |= SPMODE_REV;
/* Turn off SPI unit prior changing mode */
mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
@@ -260,7 +265,7 @@
}
/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
+#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
static int mpc83xx_spi_setup(struct spi_device *spi)
{