Merge remote-tracking branch 'spi/topic/quad' into spi-next

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

@@ -55,6 +55,16 @@ contain the following properties.
     		chip select active high
 - spi-3wire       - (optional) Empty property indicating device requires
     		    3-wire mode.
+- spi-tx-bus-width - (optional) The bus width(number of data wires) that
+                      used for MOSI. Defaults to 1 if not present.
+- spi-rx-bus-width - (optional) The bus width(number of data wires) that
+                      used for MISO. Defaults to 1 if not present.
+
+Some SPI controllers and devices support Dual and Quad SPI transfer mode.
+It allows data in SPI system transfered in 2 wires(DUAL) or 4 wires(QUAD).
+Now the value that spi-tx-bus-width and spi-rx-bus-width can receive is
+only 1(SINGLE), 2(DUAL) and 4(QUAD).
+Dual/Quad mode is not allowed when 3-wire mode is used.
 
 If a gpio chipselect is used for the SPI slave the gpio number will be passed
 via the cs_gpio

drivers/spi/spi.c

@@ -886,13 +886,8 @@ static void of_register_spi_devices(struct spi_master *master)
 			spi->mode |= SPI_3WIRE;
 
 		/* Device DUAL/QUAD mode */
-		prop = of_get_property(nc, "spi-tx-nbits", &len);
-		if (!prop || len < sizeof(*prop)) {
-			dev_err(&master->dev, "%s has no 'spi-tx-nbits' property\n",
-				nc->full_name);
-			spi_dev_put(spi);
-			continue;
-		}
+		prop = of_get_property(nc, "spi-tx-bus-width", &len);
+		if (prop && len == sizeof(*prop)) {
 			switch (be32_to_cpup(prop)) {
 			case SPI_NBITS_SINGLE:
 				break;
@@ -903,18 +898,16 @@ static void of_register_spi_devices(struct spi_master *master)
 				spi->mode |= SPI_TX_QUAD;
 				break;
 			default:
-			dev_err(&master->dev, "spi-tx-nbits value is not supported\n");
+				dev_err(&master->dev,
+					"spi-tx-bus-width %d not supported\n",
+					be32_to_cpup(prop));
 				spi_dev_put(spi);
 				continue;
 			}
-
-		prop = of_get_property(nc, "spi-rx-nbits", &len);
-		if (!prop || len < sizeof(*prop)) {
-			dev_err(&master->dev, "%s has no 'spi-rx-nbits' property\n",
-				nc->full_name);
-			spi_dev_put(spi);
-			continue;
 		}
+
+		prop = of_get_property(nc, "spi-rx-bus-width", &len);
+		if (prop && len == sizeof(*prop)) {
 			switch (be32_to_cpup(prop)) {
 			case SPI_NBITS_SINGLE:
 				break;
@@ -925,10 +918,13 @@ static void of_register_spi_devices(struct spi_master *master)
 				spi->mode |= SPI_RX_QUAD;
 				break;
 			default:
-			dev_err(&master->dev, "spi-rx-nbits value is not supported\n");
+				dev_err(&master->dev,
+					"spi-rx-bus-width %d not supported\n",
+					be32_to_cpup(prop));
 				spi_dev_put(spi);
 				continue;
 			}
+		}
 
 		/* Device speed */
 		prop = of_get_property(nc, "spi-max-frequency", &len);
@@ -1480,6 +1476,7 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
 			return -EINVAL;
 		if (xfer->speed_hz && master->max_speed_hz &&
 		    xfer->speed_hz > master->max_speed_hz)
+			return -EINVAL;
 
 		if (xfer->tx_buf && !xfer->tx_nbits)
 			xfer->tx_nbits = SPI_NBITS_SINGLE;