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, 4 insertions, 10 deletions

diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
index 0926a3e293e0..ce61be98e06d 100644
--- a/drivers/spi/spi_mpc83xx.c
+++ b/drivers/spi/spi_mpc83xx.c
@@ -419,10 +419,6 @@ static void mpc83xx_spi_work(struct work_struct *work)
         spin_unlock_irq(&mpc83xx_spi->lock);
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS        (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
-                        | SPI_LSB_FIRST | SPI_LOOP)
-
 static int mpc83xx_spi_setup(struct spi_device *spi)
 {
         struct mpc83xx_spi *mpc83xx_spi;
@@ -430,12 +426,6 @@ static int mpc83xx_spi_setup(struct spi_device *spi)
         u32 hw_mode;
         struct spi_mpc83xx_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->max_speed_hz)
                 return -EINVAL;
 
@@ -562,6 +552,10 @@ mpc83xx_spi_probe(struct device *dev, struct resource *mem, unsigned int irq)
 
         dev_set_drvdata(dev, master);
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
+                        | SPI_LSB_FIRST | SPI_LOOP;
+
         master->setup = mpc83xx_spi_setup;
         master->transfer = mpc83xx_spi_transfer;
         master->cleanup = mpc83xx_spi_cleanup;