spi: convert drivers to use bits_per_word_mask

Fill in the recently added spi_master.bits_per_word_mask field in as
many drivers as possible. Make related cleanups, such as removing any
redundant error-checking, or empty setup callbacks.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/spi/spi-txx9.c b/drivers/spi/spi-txx9.c
index adb8530..cefd956 100644
--- a/drivers/spi/spi-txx9.c
+++ b/drivers/spi/spi-txx9.c
@@ -116,17 +116,12 @@
 static int txx9spi_setup(struct spi_device *spi)
 {
 	struct txx9spi *c = spi_master_get_devdata(spi->master);
-	u8 bits_per_word;
 
 	if (!spi->max_speed_hz
 			|| spi->max_speed_hz > c->max_speed_hz
 			|| spi->max_speed_hz < c->min_speed_hz)
 		return -EINVAL;
 
-	bits_per_word = spi->bits_per_word;
-	if (bits_per_word != 8 && bits_per_word != 16)
-		return -EINVAL;
-
 	if (gpio_direction_output(spi->chip_select,
 			!(spi->mode & SPI_CS_HIGH))) {
 		dev_err(&spi->dev, "Cannot setup GPIO for chipselect.\n");
@@ -319,8 +314,6 @@
 
 		if (!t->tx_buf && !t->rx_buf && t->len)
 			return -EINVAL;
-		if (bits_per_word != 8 && bits_per_word != 16)
-			return -EINVAL;
 		if (t->len & ((bits_per_word >> 3) - 1))
 			return -EINVAL;
 		if (speed_hz < c->min_speed_hz || speed_hz > c->max_speed_hz)
@@ -411,6 +404,7 @@
 	master->setup = txx9spi_setup;
 	master->transfer = txx9spi_transfer;
 	master->num_chipselect = (u16)UINT_MAX; /* any GPIO numbers */
+	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
 
 	ret = spi_register_master(master);
 	if (ret)