spi: kirkwood_spi: implement mvebu_spi_set_mode()

Set the appropriate bits in the interface config register based
on the SPI_ mode flags.

Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Jagan Teki <jteki@openedev.com>
Signed-off-by: Chris Packham <judge.packham@gmail.com>

arch/arm/include/asm/arch-mvebu/spi.h

@@ -52,6 +52,10 @@ struct kwspi_registers {
 #define KWSPI_ADRLEN_3BYTE	(2 << 8)
 #define KWSPI_ADRLEN_4BYTE	(3 << 8)
 #define KWSPI_ADRLEN_MASK	(3 << 8)
+#define KWSPI_CPOL		(1 << 11)
+#define KWSPI_CPHA		(1 << 12)
+#define KWSPI_TXLSBF		(1 << 13)
+#define KWSPI_RXLSBF		(1 << 14)
 
 #define KWSPI_IRQUNMASK		1 /* unmask SPI interrupt */
 #define KWSPI_IRQMASK		0 /* mask SPI interrupt */

drivers/spi/kirkwood_spi.c

@@ -271,6 +271,21 @@ static int mvebu_spi_set_speed(struct udevice *bus, uint hz)
 
 static int mvebu_spi_set_mode(struct udevice *bus, uint mode)
 {
+	struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
+	struct kwspi_registers *reg = plat->spireg;
+	u32 data = readl(&reg->cfg);
+
+	data &= ~(KWSPI_CPHA | KWSPI_CPOL | KWSPI_RXLSBF | KWSPI_TXLSBF);
+
+	if (mode & SPI_CPHA)
+		data |= KWSPI_CPHA;
+	if (mode & SPI_CPOL)
+		data |= KWSPI_CPOL;
+	if (mode & SPI_LSB_FIRST)
+		data |= (KWSPI_RXLSBF | KWSPI_TXLSBF);
+
+	writel(data, &reg->cfg);
+
 	return 0;
 }