spi: txx9: Convert to let spi core handle checking transfer speed

By setting master->max_speed_hz and master->min_speed_hz, spi core will handle
checking transfer speed. Then we can remove the same checking in this driver.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-txx9.c

@@ -80,7 +80,6 @@ struct txx9spi {
 	void __iomem *membase;
 	int baseclk;
 	struct clk *clk;
-	u32 max_speed_hz, min_speed_hz;
 	int last_chipselect;
 	int last_chipselect_val;
 };
@@ -117,9 +116,7 @@ static int txx9spi_setup(struct spi_device *spi)
 {
 	struct txx9spi *c = spi_master_get_devdata(spi->master);
 
-	if (!spi->max_speed_hz
-			|| spi->max_speed_hz > c->max_speed_hz
-			|| spi->max_speed_hz < c->min_speed_hz)
+	if (!spi->max_speed_hz)
 		return -EINVAL;
 
 	if (gpio_direction_output(spi->chip_select,
@@ -309,15 +306,12 @@ static int txx9spi_transfer(struct spi_device *spi, struct spi_message *m)
 
 	/* check each transfer's parameters */
 	list_for_each_entry(t, &m->transfers, transfer_list) {
-		u32 speed_hz = t->speed_hz ? : spi->max_speed_hz;
 		u8 bits_per_word = t->bits_per_word;
 
 		if (!t->tx_buf && !t->rx_buf && t->len)
 			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)
-			return -EINVAL;
 	}
 
 	spin_lock_irqsave(&c->lock, flags);
@@ -360,8 +354,8 @@ static int txx9spi_probe(struct platform_device *dev)
 		goto exit;
 	}
 	c->baseclk = clk_get_rate(c->clk);
-	c->min_speed_hz = DIV_ROUND_UP(c->baseclk, SPI_MAX_DIVIDER + 1);
-	c->max_speed_hz = c->baseclk / (SPI_MIN_DIVIDER + 1);
+	master->min_speed_hz = DIV_ROUND_UP(c->baseclk, SPI_MAX_DIVIDER + 1);
+	master->max_speed_hz = c->baseclk / (SPI_MIN_DIVIDER + 1);
 
 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 	if (!res)