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_imx.c b/drivers/spi/spi_imx.c
index 656be4a..aee9ad6 100644
--- a/drivers/spi/spi_imx.c
+++ b/drivers/spi/spi_imx.c
@@ -1163,6 +1163,9 @@
return -EINVAL;
}
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
+
/* On first setup bad values must free chip_data memory since will cause
spi_new_device to fail. Bad value setup from protocol driver are simply not
applied and notified to the calling driver. */
@@ -1174,6 +1177,12 @@
u32 tmp;
int status = 0;
+ if (spi->mode & ~MODEBITS) {
+ dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
+ spi->mode & ~MODEBITS);
+ return -EINVAL;
+ }
+
/* Get controller data */
chip_info = spi->controller_data;
@@ -1245,21 +1254,6 @@
/* SPI mode */
tmp = spi->mode;
- if (tmp & SPI_LSB_FIRST) {
- status = -EINVAL;
- if (first_setup) {
- dev_err(&spi->dev,
- "setup - "
- "HW doesn't support LSB first transfer\n");
- goto err_first_setup;
- } else {
- dev_err(&spi->dev,
- "setup - "
- "HW doesn't support LSB first transfer, "
- "default to MSB first\n");
- spi->mode &= ~SPI_LSB_FIRST;
- }
- }
if (tmp & SPI_CS_HIGH) {
u32_EDIT(chip->control,
SPI_CONTROL_SSPOL, SPI_CONTROL_SSPOL_ACT_HIGH);