spi_mpc83xx: support loopback mode
This exposes the hardware loopback mode to drivers, primarily for testing.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
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 72812bb..0c16a2b 100644
--- a/drivers/spi/spi_mpc83xx.c
+++ b/drivers/spi/spi_mpc83xx.c
@@ -39,6 +39,7 @@
};
/* SPI Controller mode register definitions */
+#define SPMODE_LOOP (1 << 30)
#define SPMODE_CI_INACTIVEHIGH (1 << 29)
#define SPMODE_CP_BEGIN_EDGECLK (1 << 28)
#define SPMODE_DIV16 (1 << 27)
@@ -155,7 +156,7 @@
/* mask out bits we are going to set */
regval &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
| SPMODE_LEN(0xF) | SPMODE_DIV16
- | SPMODE_PM(0xF) | SPMODE_REV);
+ | SPMODE_PM(0xF) | SPMODE_REV | SPMODE_LOOP);
if (spi->mode & SPI_CPHA)
regval |= SPMODE_CP_BEGIN_EDGECLK;
@@ -163,6 +164,8 @@
regval |= SPMODE_CI_INACTIVEHIGH;
if (!(spi->mode & SPI_LSB_FIRST))
regval |= SPMODE_REV;
+ if (spi->mode & SPI_LOOP)
+ regval |= SPMODE_LOOP;
regval |= SPMODE_LEN(len);
@@ -273,7 +276,8 @@
}
/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
+#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
+ | SPI_LSB_FIRST | SPI_LOOP)
static int mpc83xx_spi_setup(struct spi_device *spi)
{