spi/mcspi: allow configuration of pin directions

Allow D0 to be an input and D1 to be an output, configurable via
platform data and a new DT property.

Based on a patch from  Matus Ujhelyi <matus.ujhelyi@streamunlimited.com>
Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

Documentation/devicetree/bindings/spi/omap-spi.txt

@@ -6,7 +6,9 @@ Required properties:
   - "ti,omap4-spi" for OMAP4+.
 - ti,spi-num-cs : Number of chipselect supported  by the instance.
 - ti,hwmods: Name of the hwmod associated to the McSPI
-
+- ti,pindir-d0-in-d1-out: Select the D0 pin as input and D1 as
+			  output. The default is D0 as output and
+			  D1 as input.
 
 Example:
 

drivers/spi/spi-omap2-mcspi.c

@@ -130,6 +130,7 @@ struct omap2_mcspi {
 	struct omap2_mcspi_dma	*dma_channels;
 	struct device		*dev;
 	struct omap2_mcspi_regs ctx;
+	unsigned int		pin_dir:1;
 };
 
 struct omap2_mcspi_cs {
@@ -765,8 +766,15 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
 	/* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
 	 * REVISIT: this controller could support SPI_3WIRE mode.
 	 */
-	l &= ~(OMAP2_MCSPI_CHCONF_IS|OMAP2_MCSPI_CHCONF_DPE1);
-	l |= OMAP2_MCSPI_CHCONF_DPE0;
+	if (mcspi->pin_dir == MCSPI_PINDIR_D0_OUT_D1_IN) {
+		l &= ~OMAP2_MCSPI_CHCONF_IS;
+		l &= ~OMAP2_MCSPI_CHCONF_DPE1;
+		l |= OMAP2_MCSPI_CHCONF_DPE0;
+	} else {
+		l |= OMAP2_MCSPI_CHCONF_IS;
+		l |= OMAP2_MCSPI_CHCONF_DPE1;
+		l &= ~OMAP2_MCSPI_CHCONF_DPE0;
+	}
 
 	/* wordlength */
 	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
@@ -1167,6 +1175,11 @@ static int __devinit omap2_mcspi_probe(struct platform_device *pdev)
 	master->cleanup = omap2_mcspi_cleanup;
 	master->dev.of_node = node;
 
+	dev_set_drvdata(&pdev->dev, master);
+
+	mcspi = spi_master_get_devdata(master);
+	mcspi->master = master;
+
 	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
 	if (match) {
 		u32 num_cs = 1; /* default number of chipselect */
@@ -1175,19 +1188,17 @@ static int __devinit omap2_mcspi_probe(struct platform_device *pdev)
 		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
 		master->num_chipselect = num_cs;
 		master->bus_num = bus_num++;
+		if (of_get_property(node, "ti,pindir-d0-in-d1-out", NULL))
+			mcspi->pin_dir = MCSPI_PINDIR_D0_IN_D1_OUT;
 	} else {
 		pdata = pdev->dev.platform_data;
 		master->num_chipselect = pdata->num_cs;
 		if (pdev->id != -1)
 			master->bus_num = pdev->id;
+		mcspi->pin_dir = pdata->pin_dir;
 	}
 	regs_offset = pdata->regs_offset;
 
-	dev_set_drvdata(&pdev->dev, master);
-
-	mcspi = spi_master_get_devdata(master);
-	mcspi->master = master;
-
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (r == NULL) {
 		status = -ENODEV;

include/linux/platform_data/spi-omap2-mcspi.h

@@ -7,9 +7,13 @@
 
 #define OMAP4_MCSPI_REG_OFFSET 0x100
 
+#define MCSPI_PINDIR_D0_OUT_D1_IN	0
+#define MCSPI_PINDIR_D0_IN_D1_OUT	1
+
 struct omap2_mcspi_platform_config {
 	unsigned short	num_cs;
 	unsigned int regs_offset;
+	unsigned int pin_dir:1;
 };
 
 struct omap2_mcspi_dev_attr {