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 b4f3b753d0f4..eee4b6e0af2c 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;