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/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
index b4f3b753d0f..eee4b6e0af2 100644
--- a/drivers/spi/omap2_mcspi.c
+++ b/drivers/spi/omap2_mcspi.c
@@ -603,9 +603,6 @@ static int omap2_mcspi_request_dma(struct spi_device *spi)
 	return 0;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
-
 static int omap2_mcspi_setup(struct spi_device *spi)
 {
 	int			ret;
@@ -613,12 +610,6 @@ static int omap2_mcspi_setup(struct spi_device *spi)
 	struct omap2_mcspi_dma	*mcspi_dma;
 	struct omap2_mcspi_cs	*cs = spi->controller_state;
 
-	if (spi->mode & ~MODEBITS) {
-		dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-			spi->mode & ~MODEBITS);
-		return -EINVAL;
-	}
-
 	if (spi->bits_per_word < 4 || spi->bits_per_word > 32) {
 		dev_dbg(&spi->dev, "setup: unsupported %d bit words\n",
 			spi->bits_per_word);
@@ -982,6 +973,9 @@ static int __init omap2_mcspi_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
 	if (pdev->id != -1)
 		master->bus_num = pdev->id;