spi: add support for octal mode I/O data transfer

Add flags for Octal mode I/O data transfer
Required for the SPI controller which can do the data transfer (TX/RX)
on 8 data lines e.g. NXP FlexSPI controller.
 SPI_TX_OCTAL: transmit with 8 wires
 SPI_RX_OCTAL: receive with 8 wires

Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur@nxp.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi.c

@@ -1633,6 +1633,9 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
 		case 4:
 			spi->mode |= SPI_TX_QUAD;
 			break;
+		case 8:
+			spi->mode |= SPI_TX_OCTAL;
+			break;
 		default:
 			dev_warn(&ctlr->dev,
 				"spi-tx-bus-width %d not supported\n",
@@ -1651,6 +1654,9 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
 		case 4:
 			spi->mode |= SPI_RX_QUAD;
 			break;
+		case 8:
+			spi->mode |= SPI_RX_OCTAL;
+			break;
 		default:
 			dev_warn(&ctlr->dev,
 				"spi-rx-bus-width %d not supported\n",
@@ -2839,7 +2845,8 @@ int spi_setup(struct spi_device *spi)
 	/* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
 	 */
 	if ((spi->mode & SPI_3WIRE) && (spi->mode &
-		(SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
+		(SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
+		 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
 		return -EINVAL;
 	/* help drivers fail *cleanly* when they need options
 	 * that aren't supported with their current controller
@@ -2848,7 +2855,8 @@ int spi_setup(struct spi_device *spi)
 	 */
 	bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
 	ugly_bits = bad_bits &
-		    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
+		    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
+		     SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
 	if (ugly_bits) {
 		dev_warn(&spi->dev,
 			 "setup: ignoring unsupported mode bits %x\n",

include/linux/spi/spi.h

@@ -154,7 +154,9 @@ struct spi_device {
 #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 */
-#define SPI_CS_WORD	0x1000			/* toggle cs after each word */
+#define	SPI_CS_WORD	0x1000			/* toggle cs after each word */
+#define	SPI_TX_OCTAL	0x2000			/* transmit with 8 wires */
+#define	SPI_RX_OCTAL	0x4000			/* receive with 8 wires */
 	int			irq;
 	void			*controller_state;
 	void			*controller_data;