spi: s3c24xx: Convert to let spi core validate bits_per_word

Set bits_per_word_mask so spi core will reject transfers that attempt to use
an unsupported bits_per_word value.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-s3c24xx.c

@@ -123,25 +123,15 @@ static int s3c24xx_spi_update_state(struct spi_device *spi,
 {
 	struct s3c24xx_spi *hw = to_hw(spi);
 	struct s3c24xx_spi_devstate *cs = spi->controller_state;
-	unsigned int bpw;
 	unsigned int hz;
 	unsigned int div;
 	unsigned long clk;
 
-	bpw = t ? t->bits_per_word : spi->bits_per_word;
 	hz  = t ? t->speed_hz : spi->max_speed_hz;
 
-	if (!bpw)
-		bpw = 8;
-
 	if (!hz)
 		hz = spi->max_speed_hz;
 
-	if (bpw != 8) {
-		dev_err(&spi->dev, "invalid bits-per-word (%d)\n", bpw);
-		return -EINVAL;
-	}
-
 	if (spi->mode != cs->mode) {
 		u8 spcon = SPCON_DEFAULT | S3C2410_SPCON_ENSCK;
 
@@ -544,6 +534,7 @@ static int s3c24xx_spi_probe(struct platform_device *pdev)
 
 	master->num_chipselect = hw->pdata->num_cs;
 	master->bus_num = pdata->bus_num;
+	master->bits_per_word_mask = SPI_BPW_MASK(8);
 
 	/* setup the state for the bitbang driver */