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>

1 files changed, 3 insertions, 9 deletions

diff --git a/drivers/spi/omap_uwire.c b/drivers/spi/omap_uwire.c
index 747d29b..aa90ddb 100644
--- a/drivers/spi/omap_uwire.c
+++ b/drivers/spi/omap_uwire.c
@@ -447,19 +447,10 @@ done:
 	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)
@@ -520,6 +511,9 @@ static int __init uwire_probe(struct platform_device *pdev)
 
 	uwire_write_reg(UWIRE_SR3, 1);
 
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
 	master->bus_num = 2;	/* "official" */
 	master->num_chipselect = 4;
 	master->setup = uwire_setup;