spi: au1550: 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. So we can remove the same checking in this driver.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/spi-au1550.c b/drivers/spi/spi-au1550.c
index c4141c9..aafb812 100644
--- a/drivers/spi/spi-au1550.c
+++ b/drivers/spi/spi-au1550.c
@@ -55,8 +55,6 @@
 
 	volatile psc_spi_t __iomem *regs;
 	int irq;
-	unsigned freq_max;
-	unsigned freq_min;
 
 	unsigned len;
 	unsigned tx_count;
@@ -248,11 +246,8 @@
 			hz = t->speed_hz;
 	}
 
-	if (hz > spi->max_speed_hz || hz > hw->freq_max || hz < hw->freq_min) {
-		dev_err(&spi->dev, "setupxfer: clock rate=%d out of range\n",
-			hz);
+	if (!hz)
 		return -EINVAL;
-	}
 
 	au1550_spi_bits_handlers_set(hw, spi->bits_per_word);
 
@@ -287,23 +282,6 @@
 	return 0;
 }
 
-static int au1550_spi_setup(struct spi_device *spi)
-{
-	struct au1550_spi *hw = spi_master_get_devdata(spi->master);
-
-	if (spi->max_speed_hz == 0)
-		spi->max_speed_hz = hw->freq_max;
-	if (spi->max_speed_hz > hw->freq_max
-			|| spi->max_speed_hz < hw->freq_min)
-		return -EINVAL;
-	/*
-	 * NOTE: cannot change speed and other hw settings immediately,
-	 *       otherwise sharing of spi bus is not possible,
-	 *       so do not call setupxfer(spi, NULL) here
-	 */
-	return 0;
-}
-
 /*
  * for dma spi transfers, we have to setup rx channel, otherwise there is
  * no reliable way how to recognize that spi transfer is done
@@ -838,7 +816,6 @@
 	hw->bitbang.master = hw->master;
 	hw->bitbang.setup_transfer = au1550_spi_setupxfer;
 	hw->bitbang.chipselect = au1550_spi_chipsel;
-	hw->bitbang.master->setup = au1550_spi_setup;
 	hw->bitbang.txrx_bufs = au1550_spi_txrx_bufs;
 
 	if (hw->usedma) {
@@ -909,8 +886,9 @@
 	{
 		int min_div = (2 << 0) * (2 * (4 + 1));
 		int max_div = (2 << 3) * (2 * (63 + 1));
-		hw->freq_max = hw->pdata->mainclk_hz / min_div;
-		hw->freq_min = hw->pdata->mainclk_hz / (max_div + 1) + 1;
+		master->max_speed_hz = hw->pdata->mainclk_hz / min_div;
+		master->min_speed_hz =
+				hw->pdata->mainclk_hz / (max_div + 1) + 1;
 	}
 
 	au1550_spi_setup_psc_as_spi(hw);