diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 9d6e85bf227b..66949d9f0cc5 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -89,7 +89,7 @@ void spi_nor_spimem_setup_op(const struct spi_nor *nor,
 		op->addr.buswidth = spi_nor_get_protocol_addr_nbits(proto);
 
 	if (op->dummy.nbytes)
-		op->dummy.buswidth = spi_nor_get_protocol_addr_nbits(proto);
+		op->dummy.buswidth = spi_nor_get_protocol_data_nbits(proto);
 
 	if (op->data.nbytes)
 		op->data.buswidth = spi_nor_get_protocol_data_nbits(proto);
@@ -113,6 +113,9 @@ void spi_nor_spimem_setup_op(const struct spi_nor *nor,
 		op->cmd.opcode = (op->cmd.opcode << 8) | ext;
 		op->cmd.nbytes = 2;
 	}
+
+	if (proto == SNOR_PROTO_8_8_8_DTR && nor->flags & SNOR_F_SWAP16)
+		op->data.swap16 = true;
 }
 
 /**
diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 1516b6d0dc37..5c33740ed7f5 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -140,6 +140,7 @@ enum spi_nor_option_flags {
 	SNOR_F_RWW		= BIT(14),
 	SNOR_F_ECC		= BIT(15),
 	SNOR_F_NO_WP		= BIT(16),
+	SNOR_F_SWAP16		= BIT(17),
 };
 
 struct spi_nor_read_command {
diff --git a/drivers/mtd/spi-nor/macronix.c b/drivers/mtd/spi-nor/macronix.c
index ea6be95e75a5..830da21eea08 100644
--- a/drivers/mtd/spi-nor/macronix.c
+++ b/drivers/mtd/spi-nor/macronix.c
@@ -8,6 +8,23 @@
 
 #include "core.h"
 
+#define MXIC_NOR_OP_RD_CR2	0x71		/* Read configuration register 2 opcode */
+#define MXIC_NOR_OP_WR_CR2	0x72		/* Write configuration register 2 opcode */
+#define MXIC_NOR_ADDR_CR2_MODE	0x00000000	/* CR2 address for setting spi/sopi/dopi mode */
+#define MXIC_NOR_ADDR_CR2_DC	0x00000300	/* CR2 address for setting dummy cycles */
+#define MXIC_NOR_REG_DOPI_EN	0x2		/* Enable Octal DTR */
+#define MXIC_NOR_REG_SPI_EN	0x0		/* Enable SPI */
+
+/* Convert dummy cycles to bit pattern */
+#define MXIC_NOR_REG_DC(p) \
+	((20 - (p)) >> 1)
+
+#define MXIC_NOR_WR_CR2(addr, ndata, buf)			\
+	SPI_MEM_OP(SPI_MEM_OP_CMD(MXIC_NOR_OP_WR_CR2, 0),	\
+		   SPI_MEM_OP_ADDR(4, addr, 0),			\
+		   SPI_MEM_OP_NO_DUMMY,				\
+		   SPI_MEM_OP_DATA_OUT(ndata, buf, 0))
+
 static int
 mx25l25635_post_bfpt_fixups(struct spi_nor *nor,
 			    const struct sfdp_parameter_header *bfpt_header,
@@ -182,9 +199,88 @@ static const struct flash_info macronix_nor_parts[] = {
 		.name = "mx25l3255e",
 		.size = SZ_4M,
 		.no_sfdp_flags = SECT_4K,
-	}
+	},
+	/*
+	 * This spares us of adding new flash entries for flashes that can be
+	 * initialized solely based on the SFDP data, but still need the
+	 * manufacturer hooks to set parameters that can't be discovered at SFDP
+	 * parsing time.
+	 */
+	{ .id = SNOR_ID(0xc2) }
 };
 
+static int macronix_nor_octal_dtr_en(struct spi_nor *nor)
+{
+	struct spi_mem_op op;
+	u8 *buf = nor->bouncebuf, i;
+	int ret;
+
+	/* Use dummy cycles which is parse by SFDP and convert to bit pattern. */
+	buf[0] = MXIC_NOR_REG_DC(nor->params->reads[SNOR_CMD_READ_8_8_8_DTR].num_wait_states);
+	op = (struct spi_mem_op)MXIC_NOR_WR_CR2(MXIC_NOR_ADDR_CR2_DC, 1, buf);
+	ret = spi_nor_write_any_volatile_reg(nor, &op, nor->reg_proto);
+	if (ret)
+		return ret;
+
+	/* Set the octal and DTR enable bits. */
+	buf[0] = MXIC_NOR_REG_DOPI_EN;
+	op = (struct spi_mem_op)MXIC_NOR_WR_CR2(MXIC_NOR_ADDR_CR2_MODE, 1, buf);
+	ret = spi_nor_write_any_volatile_reg(nor, &op, nor->reg_proto);
+	if (ret)
+		return ret;
+
+	/* Read flash ID to make sure the switch was successful. */
+	ret = spi_nor_read_id(nor, 4, 4, buf, SNOR_PROTO_8_8_8_DTR);
+	if (ret) {
+		dev_dbg(nor->dev, "error %d reading JEDEC ID after enabling 8D-8D-8D mode\n", ret);
+		return ret;
+	}
+
+	/* Macronix SPI-NOR flash 8D-8D-8D read ID would get 6 bytes data A-A-B-B-C-C */
+	for (i = 0; i < nor->info->id->len; i++)
+		if (buf[i * 2] != buf[(i * 2) + 1] || buf[i * 2] != nor->info->id->bytes[i])
+			return -EINVAL;
+
+	return 0;
+}
+
+static int macronix_nor_octal_dtr_dis(struct spi_nor *nor)
+{
+	struct spi_mem_op op;
+	u8 *buf = nor->bouncebuf;
+	int ret;
+
+	/*
+	 * The register is 1-byte wide, but 1-byte transactions are not
+	 * allowed in 8D-8D-8D mode. Since there is no register at the
+	 * next location, just initialize the value to 0 and let the
+	 * transaction go on.
+	 */
+	buf[0] = MXIC_NOR_REG_SPI_EN;
+	buf[1] = 0x0;
+	op = (struct spi_mem_op)MXIC_NOR_WR_CR2(MXIC_NOR_ADDR_CR2_MODE, 2, buf);
+	ret = spi_nor_write_any_volatile_reg(nor, &op, SNOR_PROTO_8_8_8_DTR);
+	if (ret)
+		return ret;
+
+	/* Read flash ID to make sure the switch was successful. */
+	ret = spi_nor_read_id(nor, 0, 0, buf, SNOR_PROTO_1_1_1);
+	if (ret) {
+		dev_dbg(nor->dev, "error %d reading JEDEC ID after disabling 8D-8D-8D mode\n", ret);
+		return ret;
+	}
+
+	if (memcmp(buf, nor->info->id->bytes, nor->info->id->len))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int macronix_nor_set_octal_dtr(struct spi_nor *nor, bool enable)
+{
+	return enable ? macronix_nor_octal_dtr_en(nor) : macronix_nor_octal_dtr_dis(nor);
+}
+
 static void macronix_nor_default_init(struct spi_nor *nor)
 {
 	nor->params->quad_enable = spi_nor_sr1_bit6_quad_enable;
@@ -194,6 +290,7 @@ static int macronix_nor_late_init(struct spi_nor *nor)
 {
 	if (!nor->params->set_4byte_addr_mode)
 		nor->params->set_4byte_addr_mode = spi_nor_set_4byte_addr_mode_en4b_ex4b;
+	nor->params->set_octal_dtr = macronix_nor_set_octal_dtr;
 
 	return 0;
 }
diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
index 5b1117265bd2..21727f9a4ac6 100644
--- a/drivers/mtd/spi-nor/sfdp.c
+++ b/drivers/mtd/spi-nor/sfdp.c
@@ -671,6 +671,10 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
 		return -EOPNOTSUPP;
 	}
 
+	/* Byte order in 8D-8D-8D mode */
+	if (bfpt.dwords[SFDP_DWORD(18)] & BFPT_DWORD18_BYTE_ORDER_SWAPPED)
+		nor->flags |= SNOR_F_SWAP16;
+
 	return spi_nor_post_bfpt_fixups(nor, bfpt_header, &bfpt);
 }
 
diff --git a/drivers/mtd/spi-nor/sfdp.h b/drivers/mtd/spi-nor/sfdp.h
index da0fe5aa9bb0..f74a0eb339ea 100644
--- a/drivers/mtd/spi-nor/sfdp.h
+++ b/drivers/mtd/spi-nor/sfdp.h
@@ -130,6 +130,7 @@ struct sfdp_bfpt {
 #define BFPT_DWORD18_CMD_EXT_INV		(0x1UL << 29) /* Invert */
 #define BFPT_DWORD18_CMD_EXT_RES		(0x2UL << 29) /* Reserved */
 #define BFPT_DWORD18_CMD_EXT_16B		(0x3UL << 29) /* 16-bit opcode */
+#define BFPT_DWORD18_BYTE_ORDER_SWAPPED		BIT(31)	/* Byte order swapped in 8D-8D-8D mode */
 
 struct sfdp_parameter_header {
 	u8		id_lsb;
diff --git a/drivers/mtd/spi-nor/spansion.c b/drivers/mtd/spi-nor/spansion.c
index d6c92595f6bc..5a88a6096ca8 100644
--- a/drivers/mtd/spi-nor/spansion.c
+++ b/drivers/mtd/spi-nor/spansion.c
@@ -106,6 +106,7 @@ static int cypress_nor_sr_ready_and_clear_reg(struct spi_nor *nor, u64 addr)
 	int ret;
 
 	if (nor->reg_proto == SNOR_PROTO_8_8_8_DTR) {
+		op.addr.nbytes = nor->addr_nbytes;
 		op.dummy.nbytes = params->rdsr_dummy;
 		op.data.nbytes = 2;
 	}
diff --git a/drivers/mtd/spi-nor/winbond.c b/drivers/mtd/spi-nor/winbond.c
index 9f7ce5763e71..8d0a00d69e12 100644
--- a/drivers/mtd/spi-nor/winbond.c
+++ b/drivers/mtd/spi-nor/winbond.c
@@ -129,6 +129,7 @@ static const struct flash_info winbond_nor_parts[] = {
 		.no_sfdp_flags = SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ,
 	}, {
 		.id = SNOR_ID(0xef, 0x40, 0x18),
+		/* Flavors w/ and w/o SFDP. */
 		.name = "w25q128",
 		.size = SZ_16M,
 		.flags = SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB,
diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index 17b8baf749e6..abc6792e738c 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -172,6 +172,9 @@ bool spi_mem_default_supports_op(struct spi_mem *mem,
 		if (!spi_mem_controller_is_capable(ctlr, dtr))
 			return false;
 
+		if (op->data.swap16 && !spi_mem_controller_is_capable(ctlr, swap16))
+			return false;
+
 		if (op->cmd.nbytes != 2)
 			return false;
 	} else {
diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index 6156d691630a..a669ffa27b65 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c
@@ -294,7 +294,8 @@ static void mxic_spi_hw_init(struct mxic_spi *mxic)
 	       mxic->regs + HC_CFG);
 }
 
-static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags)
+static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags,
+				bool swap16)
 {
 	int nio = 1;
 
@@ -305,6 +306,11 @@ static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags)
 	else if (spi->mode & (SPI_TX_DUAL | SPI_RX_DUAL))
 		nio = 2;
 
+	if (swap16)
+		flags &= ~HC_CFG_DATA_PASS;
+	else
+		flags |= HC_CFG_DATA_PASS;
+
 	return flags | HC_CFG_NIO(nio) |
 	       HC_CFG_TYPE(spi_get_chipselect(spi, 0), HC_CFG_TYPE_SPI_NOR) |
 	       HC_CFG_SLV_ACT(spi_get_chipselect(spi, 0)) | HC_CFG_IDLE_SIO_LVL(1);
@@ -397,7 +403,8 @@ static ssize_t mxic_spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
 	if (WARN_ON(offs + desc->info.offset + len > U32_MAX))
 		return -EINVAL;
 
-	writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0), mxic->regs + HC_CFG);
+	writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0, desc->info.op_tmpl.data.swap16),
+	       mxic->regs + HC_CFG);
 
 	writel(mxic_spi_mem_prep_op_cfg(&desc->info.op_tmpl, len),
 	       mxic->regs + LRD_CFG);
@@ -441,7 +448,8 @@ static ssize_t mxic_spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
 	if (WARN_ON(offs + desc->info.offset + len > U32_MAX))
 		return -EINVAL;
 
-	writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0), mxic->regs + HC_CFG);
+	writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0, desc->info.op_tmpl.data.swap16),
+	       mxic->regs + HC_CFG);
 
 	writel(mxic_spi_mem_prep_op_cfg(&desc->info.op_tmpl, len),
 	       mxic->regs + LWR_CFG);
@@ -518,7 +526,7 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 	if (ret)
 		return ret;
 
-	writel(mxic_spi_prep_hc_cfg(mem->spi, HC_CFG_MAN_CS_EN),
+	writel(mxic_spi_prep_hc_cfg(mem->spi, HC_CFG_MAN_CS_EN, op->data.swap16),
 	       mxic->regs + HC_CFG);
 
 	writel(HC_EN_BIT, mxic->regs + HC_EN);
@@ -573,6 +581,7 @@ static const struct spi_controller_mem_ops mxic_spi_mem_ops = {
 static const struct spi_controller_mem_caps mxic_spi_mem_caps = {
 	.dtr = true,
 	.ecc = true,
+	.swap16 = true,
 };
 
 static void mxic_spi_set_cs(struct spi_device *spi, bool lvl)
diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
index f866d5c8ed32..c46d2b8029be 100644
--- a/include/linux/spi/spi-mem.h
+++ b/include/linux/spi/spi-mem.h
@@ -90,6 +90,8 @@ enum spi_mem_data_dir {
  * @data.buswidth: number of IO lanes used to send/receive the data
  * @data.dtr: whether the data should be sent in DTR mode or not
  * @data.ecc: whether error correction is required or not
+ * @data.swap16: whether the byte order of 16-bit words is swapped when read
+ *		 or written in Octal DTR mode compared to STR mode.
  * @data.dir: direction of the transfer
  * @data.nbytes: number of data bytes to send/receive. Can be zero if the
  *		 operation does not involve transferring data
@@ -124,7 +126,8 @@ struct spi_mem_op {
 		u8 buswidth;
 		u8 dtr : 1;
 		u8 ecc : 1;
-		u8 __pad : 6;
+		u8 swap16 : 1;
+		u8 __pad : 5;
 		enum spi_mem_data_dir dir;
 		unsigned int nbytes;
 		union {
@@ -297,10 +300,13 @@ struct spi_controller_mem_ops {
  * struct spi_controller_mem_caps - SPI memory controller capabilities
  * @dtr: Supports DTR operations
  * @ecc: Supports operations with error correction
+ * @swap16: Supports swapping bytes on a 16 bit boundary when configured in
+ *	    Octal DTR
  */
 struct spi_controller_mem_caps {
 	bool dtr;
 	bool ecc;
+	bool swap16;
 };
 
 #define spi_mem_controller_is_capable(ctlr, cap)	\