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, 0 deletions

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 0db5d64fc5e8..9c4cd27f4685 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -245,6 +245,9 @@ struct spi_master {
          */
         u16                     dma_alignment;
 
+        /* spi_device.mode flags understood by this controller driver */
+        u16                     mode_bits;
+
         /* Setup mode and clock, etc (spi driver may call many times).
          *
          * IMPORTANT:  this may be called when transfers to another