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/mpc52xx_psc_spi.c b/drivers/spi/mpc52xx_psc_spi.c
index 68c77a911595..bdae9f908978 100644
--- a/drivers/spi/mpc52xx_psc_spi.c
+++ b/drivers/spi/mpc52xx_psc_spi.c
@@ -261,9 +261,6 @@ static void mpc52xx_psc_spi_work(struct work_struct *work)
         spin_unlock_irq(&mps->lock);
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
-
 static int mpc52xx_psc_spi_setup(struct spi_device *spi)
 {
         struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
@@ -273,12 +270,6 @@ static int mpc52xx_psc_spi_setup(struct spi_device *spi)
         if (spi->bits_per_word%8)
                 return -EINVAL;
 
-        if (spi->mode & ~MODEBITS) {
-                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         if (!cs) {
                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
                 if (!cs)
@@ -385,6 +376,9 @@ static int __init mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
         dev_set_drvdata(dev, master);
         mps = spi_master_get_devdata(master);
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
+
         mps->irq = irq;
         if (pdata == NULL) {
                 dev_warn(dev, "probe called without platform data, no "