SPI loopback mode definition

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

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/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 302b81d1d1176999e61dc2b5b5db8ae5b320a21c..e180615ed25a013e32e7ec65a050bc59c1e07925 100644 (file)
--- 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;