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>
diff --git a/drivers/spi/omap_uwire.c b/drivers/spi/omap_uwire.c
index 95183e1..d275c61 100644
--- a/drivers/spi/omap_uwire.c
+++ b/drivers/spi/omap_uwire.c
@@ -445,10 +445,19 @@
return status;
}
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
+
static int uwire_setup(struct spi_device *spi)
{
struct uwire_state *ust = spi->controller_state;
+ if (spi->mode & ~MODEBITS) {
+ dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
+ spi->mode & ~MODEBITS);
+ return -EINVAL;
+ }
+
if (ust == NULL) {
ust = kzalloc(sizeof(*ust), GFP_KERNEL);
if (ust == NULL)