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/au1550_spi.c b/drivers/spi/au1550_spi.c
index 6a407e60f05..76cbc1a6659 100644
--- a/drivers/spi/au1550_spi.c
+++ b/drivers/spi/au1550_spi.c
@@ -284,9 +284,6 @@ static int au1550_spi_setupxfer(struct spi_device *spi, struct spi_transfer *t)
 	return 0;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
-
 static int au1550_spi_setup(struct spi_device *spi)
 {
 	struct au1550_spi *hw = spi_master_get_devdata(spi->master);
@@ -297,12 +294,6 @@ static int au1550_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;
-	}
-
 	if (spi->max_speed_hz == 0)
 		spi->max_speed_hz = hw->freq_max;
 	if (spi->max_speed_hz > hw->freq_max
@@ -779,6 +770,9 @@ static int __init au1550_spi_probe(struct platform_device *pdev)
 		goto err_nomem;
 	}
 
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
+
 	hw = spi_master_get_devdata(master);
 
 	hw->master = spi_master_get(master);