spi: Add support for dual and quad mode

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@ti.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>
Signed-off-by: Jagan Teki <jteki@openedev.com>

drivers/spi/spi-uclass.c

@@ -157,6 +157,7 @@ static int spi_child_pre_probe(struct udevice *dev)
 
 	slave->max_hz = plat->max_hz;
 	slave->mode = plat->mode;
+	slave->mode_rx = plat->mode_rx;
 
 	return 0;
 }
@@ -368,7 +369,8 @@ void spi_free_slave(struct spi_slave *slave)
 int spi_slave_ofdata_to_platdata(const void *blob, int node,
 				 struct dm_spi_slave_platdata *plat)
 {
-	int mode = 0;
+	int mode = 0, mode_rx = 0;
+	int value;
 
 	plat->cs = fdtdec_get_int(blob, node, "reg", -1);
 	plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0);
@@ -382,8 +384,42 @@ int spi_slave_ofdata_to_platdata(const void *blob, int node,
 		mode |= SPI_3WIRE;
 	if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
 		mode |= SPI_PREAMBLE;
+
+	/* Device DUAL/QUAD mode */
+	value = fdtdec_get_uint(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;
+	}
+
 	plat->mode = mode;
 
+	value = fdtdec_get_uint(blob, node, "spi-rx-bus-width", 1);
+	switch (value) {
+	case 1:
+		break;
+	case 2:
+		mode_rx |= SPI_RX_DUAL;
+		break;
+	case 4:
+		mode_rx |= SPI_RX_QUAD;
+		break;
+	default:
+		error("spi-rx-bus-width %d not supported\n", value);
+		break;
+	}
+
+	plat->mode_rx = mode_rx;
+
 	return 0;
 }
 

include/spi.h

@@ -61,11 +61,13 @@ struct dm_spi_bus {
  * @cs:		Chip select number (0..n-1)
  * @max_hz:	Maximum bus speed that this slave can tolerate
  * @mode:	SPI mode to use for this device (see SPI mode flags)
+ * @mode_rx:	SPI RX mode to use for this slave (see SPI mode_rx flags)
  */
 struct dm_spi_slave_platdata {
 	unsigned int cs;
 	uint max_hz;
 	uint mode;
+	u8 mode_rx;
 };
 
 #endif /* CONFIG_DM_SPI */