1 files changed, 52 insertions, 2 deletions

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 02236e8..792354a 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -73,7 +73,20 @@ static int read_cr(struct spi_nor *nor)
  */
 static inline int spi_nor_read_dummy_cycles(struct spi_nor *nor)
 {
+	u32 dummy;
+
 	switch (nor->flash_read) {
+	case SPI_NOR_DDR_QUAD:
+		/*
+		 * The m25p80.c can not support the DDR quad read.
+		 * We set the dummy cycles to 8 by default. The SPI NOR
+		 * controller driver can set it in its child DT node.
+		 * We parse it out here.
+		 */
+		if (nor->np && !of_property_read_u32(nor->np,
+				"spi-nor,ddr-quad-read-dummy", &dummy)) {
+			return dummy;
+		}
 	case SPI_NOR_FAST:
 	case SPI_NOR_DUAL:
 	case SPI_NOR_QUAD:
@@ -402,6 +415,7 @@ struct flash_info {
 #define	SECT_4K_PMC		0x10	/* SPINOR_OP_BE_4K_PMC works uniformly */
 #define	SPI_NOR_DUAL_READ	0x20    /* Flash supports Dual Read */
 #define	SPI_NOR_QUAD_READ	0x40    /* Flash supports Quad Read */
+#define	SPI_NOR_DDR_QUAD_READ	0x80    /* Flash supports DDR Quad Read */
 };
 
 #define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags)	\
@@ -829,6 +843,24 @@ static int spansion_quad_enable(struct spi_nor *nor)
 	return 0;
 }
 
+static int set_ddr_quad_mode(struct spi_nor *nor, u32 jedec_id)
+{
+	int status;
+
+	switch (JEDEC_MFR(jedec_id)) {
+	case CFI_MFR_AMD: /* Spansion, actually */
+		status = spansion_quad_enable(nor);
+		if (status) {
+			dev_err(nor->dev,
+				"Spansion DDR quad-read not enabled\n");
+			return status;
+		}
+		return status;
+	default:
+		return -EINVAL;
+	}
+}
+
 static int set_quad_mode(struct spi_nor *nor, u32 jedec_id)
 {
 	int status;
@@ -999,8 +1031,15 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
 	if (info->flags & SPI_NOR_NO_FR)
 		nor->flash_read = SPI_NOR_NORMAL;
 
-	/* Quad/Dual-read mode takes precedence over fast/normal */
-	if (mode == SPI_NOR_QUAD && info->flags & SPI_NOR_QUAD_READ) {
+	/* DDR Quad/Quad/Dual-read mode takes precedence over fast/normal */
+	if (mode == SPI_NOR_DDR_QUAD && info->flags & SPI_NOR_DDR_QUAD_READ) {
+		ret = set_ddr_quad_mode(nor, info->jedec_id);
+		if (ret) {
+			dev_err(dev, "DDR quad mode not supported\n");
+			return ret;
+		}
+		nor->flash_read = SPI_NOR_DDR_QUAD;
+	} else if (mode == SPI_NOR_QUAD && info->flags & SPI_NOR_QUAD_READ) {
 		ret = set_quad_mode(nor, info->jedec_id);
 		if (ret) {
 			dev_err(dev, "quad mode not supported\n");
@@ -1013,6 +1052,14 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
 
 	/* Default commands */
 	switch (nor->flash_read) {
+	case SPI_NOR_DDR_QUAD:
+		if (JEDEC_MFR(info->jedec_id) == CFI_MFR_AMD) { /* Spansion */
+			nor->read_opcode = SPINOR_OP_READ_1_4_4_D;
+		} else {
+			dev_err(dev, "DDR Quad Read is not supported.\n");
+			return -EINVAL;
+		}
+		break;
 	case SPI_NOR_QUAD:
 		nor->read_opcode = SPINOR_OP_READ_1_1_4;
 		break;
@@ -1040,6 +1087,9 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id,
 		if (JEDEC_MFR(info->jedec_id) == CFI_MFR_AMD) {
 			/* Dedicated 4-byte command set */
 			switch (nor->flash_read) {
+			case SPI_NOR_DDR_QUAD:
+				nor->read_opcode = SPINOR_OP_READ4_1_4_4_D;
+				break;
 			case SPI_NOR_QUAD:
 				nor->read_opcode = SPINOR_OP_READ4_1_1_4;
 				break;