spidev supports more communications modes

The spidev driver doesn't currently expose all SPI communications modes to
userspace.  This passes them all through to the driver.

Two of them are potentially troublesome, in the sense that they could cause
hardware conflicts on shared busses.  It might be appropriate to add some
privilege checks for for those modes.

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>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/spi/spidev.h b/include/linux/spi/spidev.h
index 7d700be57490..c93ef9d42a01 100644
--- a/include/linux/spi/spidev.h
+++ b/include/linux/spi/spidev.h
@@ -35,6 +35,10 @@
 #define SPI_MODE_2              (SPI_CPOL|0)
 #define SPI_MODE_3              (SPI_CPOL|SPI_CPHA)
 
+#define SPI_CS_HIGH             0x04
+#define SPI_LSB_FIRST           0x08
+#define SPI_3WIRE               0x10
+#define SPI_LOOP                0x20
 
 /*---------------------------------------------------------------------------*/