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, 6 deletions

diff --git a/drivers/spi/spi_txx9.c b/drivers/spi/spi_txx9.c
index 8e36b2153d9a..96057de133ad 100644
--- a/drivers/spi/spi_txx9.c
+++ b/drivers/spi/spi_txx9.c
@@ -110,17 +110,11 @@ static void txx9spi_cs_func(struct spi_device *spi, struct txx9spi *c,
         ndelay(cs_delay);       /* CS Setup Time / CS Recovery Time */
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS        (SPI_CS_HIGH|SPI_CPOL|SPI_CPHA)
-
 static int txx9spi_setup(struct spi_device *spi)
 {
         struct txx9spi *c = spi_master_get_devdata(spi->master);
         u8 bits_per_word;
 
-        if (spi->mode & ~MODEBITS)
-                return -EINVAL;
-
         if (!spi->max_speed_hz
                         || spi->max_speed_hz > c->max_speed_hz
                         || spi->max_speed_hz < c->min_speed_hz)
@@ -414,6 +408,9 @@ static int __init txx9spi_probe(struct platform_device *dev)
                  (unsigned long long)res->start, irq,
                  (c->baseclk + 500000) / 1000000);
 
+        /* the spi->mode bits understood by this driver: */
+        master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
+
         master->bus_num = dev->id;
         master->setup = txx9spi_setup;
         master->transfer = txx9spi_transfer;