[PATCH 2/3] [SPI] Add new mode: SPI_LOOP

[Anton Vorontsov]

Loopback mode is supported by various controllers, this mode
is useful for testing, especially in conjunction with spidev
driver.

Signed-off-by: Anton Vorontsov <avorontsov at ru.mvista.com>
---
 drivers/spi/spidev.c       |    2 +-
 include/linux/spi/spi.h    |    1 +
 include/linux/spi/spidev.h |    1 +
 3 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 4c51a61..24c8d4d 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -57,7 +57,7 @@ static unsigned long	minors[N_SPI_MINORS / BITS_PER_LONG];
 
 /* Bit masks for spi_device.mode management */
 #define SPI_MODE_MASK			(SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | \
-					 SPI_LSB_FIRST | SPI_3WIRE)
+					 SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP)
 
 struct spidev_data {
 	struct device		dev;
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 302b81d..e180615 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -77,6 +77,7 @@ struct spi_device {
 #define	SPI_CS_HIGH	0x04			/* chipselect active high? */
 #define	SPI_LSB_FIRST	0x08			/* per-word bits-on-wire */
 #define	SPI_3WIRE	0x10			/* SI/SO signals shared */
+#define	SPI_LOOP	0x20			/* loopback mode */
 	u8			bits_per_word;
 	int			irq;
 	void			*controller_state;
diff --git a/include/linux/spi/spidev.h b/include/linux/spi/spidev.h
index 369d42e..c93ef9d 100644
--- a/include/linux/spi/spidev.h
+++ b/include/linux/spi/spidev.h
@@ -38,6 +38,7 @@
 #define SPI_CS_HIGH		0x04
 #define SPI_LSB_FIRST		0x08
 #define SPI_3WIRE		0x10
+#define SPI_LOOP		0x20
 
 /*---------------------------------------------------------------------------*/
 
-- 
1.5.0.6