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/spi_s3c24xx.c b/drivers/spi/spi_s3c24xx.c
index d5a710f..7071ff8 100644
--- a/drivers/spi/spi_s3c24xx.c
+++ b/drivers/spi/spi_s3c24xx.c
@@ -146,6 +146,9 @@
return 0;
}
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
+
static int s3c24xx_spi_setup(struct spi_device *spi)
{
int ret;
@@ -153,8 +156,11 @@
if (!spi->bits_per_word)
spi->bits_per_word = 8;
- if ((spi->mode & SPI_LSB_FIRST) != 0)
+ if (spi->mode & ~MODEBITS) {
+ dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
+ spi->mode & ~MODEBITS);
return -EINVAL;
+ }
ret = s3c24xx_spi_setupxfer(spi, NULL);
if (ret < 0) {