[U-Boot] [PATCH 03/13] spi: Add support for dual and quad mode

[Mugunthan V N]

spi bus can support dual and quad wire data transfers for tx and
rx. So defining dual and quad modes for both tx and rx. Also add
support to parse bus width used for spi tx and rx transfers.

Signed-off-by: Mugunthan V N <mugunthanvnm at ti.com>
---
 drivers/spi/spi-uclass.c | 33 +++++++++++++++++++++++++++++++++
 include/spi.h            |  4 ++++
 2 files changed, 37 insertions(+)

diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
index d666272..9a32b6c 100644
--- a/drivers/spi/spi-uclass.c
+++ b/drivers/spi/spi-uclass.c
@@ -349,6 +349,7 @@ int spi_slave_ofdata_to_platdata(const void *blob, int node,
 				 struct dm_spi_slave_platdata *plat)
 {
 	int mode = 0;
+	int value;
 
 	plat->cs = fdtdec_get_int(blob, node, "reg", -1);
 	plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0);
@@ -360,6 +361,38 @@ int spi_slave_ofdata_to_platdata(const void *blob, int node,
 		mode |= SPI_CS_HIGH;
 	if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
 		mode |= SPI_PREAMBLE;
+
+	/* Device DUAL/QUAD mode */
+	value = fdtdec_get_int(blob, node, "spi-tx-bus-width", 1);
+	switch (value) {
+	case 1:
+		break;
+	case 2:
+		mode |= SPI_TX_DUAL;
+		break;
+	case 4:
+		mode |= SPI_TX_QUAD;
+		break;
+	default:
+		error("spi-tx-bus-width %d not supported\n", value);
+		break;
+	}
+
+	value = fdtdec_get_int(blob, node, "spi-rx-bus-width", 1);
+	switch (value) {
+	case 1:
+		break;
+	case 2:
+		mode |= SPI_RX_DUAL;
+		break;
+	case 4:
+		mode |= SPI_RX_QUAD;
+		break;
+	default:
+		error("spi-rx-bus-width %d not supported\n", value);
+		break;
+	}
+
 	plat->mode = mode;
 
 	return 0;
diff --git a/include/spi.h b/include/spi.h
index 51fdfd6..57f6ffe 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -23,6 +23,10 @@
 #define	SPI_LOOP	0x20			/* loopback mode */
 #define	SPI_SLAVE	0x40			/* slave mode */
 #define	SPI_PREAMBLE	0x80			/* Skip preamble bytes */
+#define	SPI_TX_DUAL	0x100			/* transmit with 2 wires */
+#define	SPI_TX_QUAD	0x200			/* transmit with 4 wires */
+#define	SPI_RX_DUAL	0x400			/* receive with 2 wires */
+#define	SPI_RX_QUAD	0x800			/* receive with 4 wires */
 
 /* SPI transfer flags */
 #define SPI_XFER_BEGIN		0x01	/* Assert CS before transfer */
-- 
2.6.2.280.g74301d6