spi: move more spi_setup() functionality into core
Move some common spi_setup() error checks into the SPI framework from the
spi_master controller drivers:
- Add a new "mode_bits" field to spi_master
- Use that in spi_setup to validate the spi->mode value being
requested. Setting this new field is now mandatory for any
controller supporting more than vanilla SPI_MODE_0.
- Update all spi_master drivers to:
* Initialize that field
* Remove current spi_setup() checks using that value.
This is a net minor code shrink.
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.c b/drivers/spi/spi.c
index 0276bc3..a525a3a 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -607,8 +607,19 @@
*/
int spi_setup(struct spi_device *spi)
{
+ unsigned bad_bits;
int status;
+ /* help drivers fail *cleanly* when they need options
+ * that aren't supported with their current master
+ */
+ bad_bits = spi->mode & ~spi->master->mode_bits;
+ if (bad_bits) {
+ dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
+ bad_bits);
+ return -EINVAL;
+ }
+
if (!spi->bits_per_word)
spi->bits_per_word = 8;