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 9f9ff3af72d..f5b3fdbb1e2 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;