2 files changed, 47 insertions, 40 deletions

diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
index 296015e3c632..800dafe5b01b 100644
--- a/Documentation/devicetree/bindings/spi/spi-bus.txt
+++ b/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
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 6ef349f82b5f..9e039c60c068 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -886,48 +886,44 @@ 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;
-                }
-                switch (be32_to_cpup(prop)) {
-                case SPI_NBITS_SINGLE:
-                        break;
-                case SPI_NBITS_DUAL:
-                        spi->mode |= SPI_TX_DUAL;
-                        break;
-                case SPI_NBITS_QUAD:
-                        spi->mode |= SPI_TX_QUAD;
-                        break;
-                default:
-                        dev_err(&master->dev, "spi-tx-nbits value is not supported\n");
-                        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;
+                        case SPI_NBITS_DUAL:
+                                spi->mode |= SPI_TX_DUAL;
+                                break;
+                        case SPI_NBITS_QUAD:
+                                spi->mode |= SPI_TX_QUAD;
+                                break;
+                        default:
+                                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;
-                }
-                switch (be32_to_cpup(prop)) {
-                case SPI_NBITS_SINGLE:
-                        break;
-                case SPI_NBITS_DUAL:
-                        spi->mode |= SPI_RX_DUAL;
-                        break;
-                case SPI_NBITS_QUAD:
-                        spi->mode |= SPI_RX_QUAD;
-                        break;
-                default:
-                        dev_err(&master->dev, "spi-rx-nbits value is not supported\n");
-                        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;
+                        case SPI_NBITS_DUAL:
+                                spi->mode |= SPI_RX_DUAL;
+                                break;
+                        case SPI_NBITS_QUAD:
+                                spi->mode |= SPI_RX_QUAD;
+                                break;
+                        default:
+                                dev_err(&master->dev,
+                                        "spi-rx-bus-width %d not supported\n",
+                                        be32_to_cpup(prop));
+                                spi_dev_put(spi);
+                                continue;
+                        }
                 }
 
                 /* Device speed */
@@ -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;