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/atmel_spi.c b/drivers/spi/atmel_spi.c
index 9f9ff3af72d7..f5b3fdbb1e27 100644
--- a/drivers/spi/atmel_spi.c
+++ b/drivers/spi/atmel_spi.c
@@ -530,9 +530,6 @@ atmel_spi_interrupt(int irq, void *dev_id)
         return ret;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
-
 static int atmel_spi_setup(struct spi_device *spi)
 {
         struct atmel_spi        *as;
@@ -562,12 +559,6 @@ static int atmel_spi_setup(struct spi_device *spi)
                 return -EINVAL;
         }
 
-        if (spi->mode & ~MODEBITS) {
-                dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
-                        spi->mode & ~MODEBITS);
-                return -EINVAL;
-        }
-
         /* see notes above re chipselect */
         if (!atmel_spi_is_v2()
                         && spi->chip_select == 0
@@ -773,6 +764,9 @@ static int __init atmel_spi_probe(struct platform_device *pdev)
         if (!master)
                 goto out_free;
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
         master->bus_num = pdev->id;
         master->num_chipselect = 4;
         master->setup = atmel_spi_setup;