spi: omap2-mcspi: Convert to let spi core validate transfer speed

Set master->max_speed_hz and master->min_speed_hz then 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>

drivers/spi/spi-omap2-mcspi.c

@@ -1213,8 +1213,7 @@ static int omap2_mcspi_transfer_one_message(struct spi_master *master,
 		void		*rx_buf = t->rx_buf;
 		unsigned	len = t->len;
 
-		if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ
-				|| (len && !(rx_buf || tx_buf))) {
+		if ((len && !(rx_buf || tx_buf))) {
 			dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
 					t->speed_hz,
 					len,
@@ -1223,12 +1222,6 @@ static int omap2_mcspi_transfer_one_message(struct spi_master *master,
 					t->bits_per_word);
 			return -EINVAL;
 		}
-		if (t->speed_hz && t->speed_hz < (OMAP2_MCSPI_MAX_FREQ >> 15)) {
-			dev_dbg(mcspi->dev, "speed_hz %d below minimum %d Hz\n",
-					t->speed_hz,
-					OMAP2_MCSPI_MAX_FREQ >> 15);
-			return -EINVAL;
-		}
 
 		if (m->is_dma_mapped || len < DMA_MIN_BYTES)
 			continue;
@@ -1340,6 +1333,8 @@ static int omap2_mcspi_probe(struct platform_device *pdev)
 	master->transfer_one_message = omap2_mcspi_transfer_one_message;
 	master->cleanup = omap2_mcspi_cleanup;
 	master->dev.of_node = node;
+	master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
+	master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
 
 	platform_set_drvdata(pdev, master);