SPI controller drivers: check for unsupported modes

Minor SPI controller driver updates: make the setup() methods reject
spi->mode bits they don't support, by masking aginst the inverse of bits
they *do* support.  This insures against misbehavior later when new mode
bits get added.

Most controllers can't support SPI_LSB_FIRST; more handle SPI_CS_HIGH.
Support for all four SPI clock/transfer modes is routine.

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, 1 insertions, 0 deletions

diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h
index 9dbca629dcfb..b8db32cea1de 100644
--- a/include/linux/spi/spi_bitbang.h
+++ b/include/linux/spi/spi_bitbang.h
@@ -26,6 +26,7 @@ struct spi_bitbang {
         struct list_head        queue;
         u8                      busy;
         u8                      use_dma;
+        u8                      flags;          /* extra spi->mode support */
 
         struct spi_master       *master;