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/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c
index c7365e0..9c311dc 100644
--- a/drivers/spi/pxa2xx_spi.c
+++ b/drivers/spi/pxa2xx_spi.c
@@ -1185,9 +1185,6 @@ static int transfer(struct spi_device *spi, struct spi_message *msg)
 	return 0;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA)
-
 static int setup_cs(struct spi_device *spi, struct chip_data *chip,
 		    struct pxa2xx_spi_chip *chip_info)
 {
@@ -1252,12 +1249,6 @@ static int 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;
-	}
-
 	/* Only alloc on first setup */
 	chip = spi_get_ctldata(spi);
 	if (!chip) {
@@ -1493,6 +1484,9 @@ static int __init pxa2xx_spi_probe(struct platform_device *pdev)
 	drv_data->pdev = pdev;
 	drv_data->ssp = ssp;
 
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA;
+
 	master->bus_num = pdev->id;
 	master->num_chipselect = platform_info->num_chipselect;
 	master->dma_alignment = DMA_ALIGNMENT;