[PATCH 1/3] mtd: spi-nor: Add Octal mode support for mt35xu512aba

[Vignesh R <vigneshr@xxxxxx>]

Micron's mt35xu512aba flash is an Octal flash that has x8 IO lines. It
supports read/write over 8 IO lines simulatenously. Add support for
Octal read mode for Micron mt35xu512aba.
Unfortunately, this flash is only complaint to SFDP JESD216B and does not
seem to support newer JESD216C standard that provides auto detection of
Octal mode capabilities and opcodes. Therefore, this capability is
manually added using new SPI_NOR_OCTAL_READ flag.

Signed-off-by: Vignesh R <vigneshr@xxxxxx>
---
 drivers/mtd/spi-nor/spi-nor.c | 11 ++++++++++-
 include/linux/mtd/spi-nor.h   |  2 ++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index aff5e6ff0b2c..4926e805a8cb 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -90,6 +90,7 @@ struct flash_info {
 #define NO_CHIP_ERASE		BIT(12) /* Chip does not support chip erase */
 #define SPI_NOR_SKIP_SFDP	BIT(13)	/* Skip parsing of SFDP tables */
 #define USE_CLSR		BIT(14)	/* use CLSR command */
+#define SPI_NOR_OCTAL_READ	BIT(15)	/* Flash supports Octal Read */
 
 	int	(*quad_enable)(struct spi_nor *nor);
 };
@@ -209,6 +210,7 @@ static inline u8 spi_nor_convert_3to4_read(u8 opcode)
 		{ SPINOR_OP_READ_1_2_2,	SPINOR_OP_READ_1_2_2_4B },
 		{ SPINOR_OP_READ_1_1_4,	SPINOR_OP_READ_1_1_4_4B },
 		{ SPINOR_OP_READ_1_4_4,	SPINOR_OP_READ_1_4_4_4B },
+		{ SPINOR_OP_READ_1_1_8,	SPINOR_OP_READ_1_1_8_4B },
 
 		{ SPINOR_OP_READ_1_1_1_DTR,	SPINOR_OP_READ_1_1_1_DTR_4B },
 		{ SPINOR_OP_READ_1_2_2_DTR,	SPINOR_OP_READ_1_2_2_DTR_4B },
@@ -1406,7 +1408,7 @@ static const struct flash_info spi_nor_ids[] = {
 	{ "mt25qu02g",   INFO(0x20bb22, 0, 64 * 1024, 4096, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ | NO_CHIP_ERASE) },
 
 	/* Micron */
-	{ "mt35xu512aba", INFO(0x2c5b1a, 0, 128 * 1024, 512, SECT_4K | USE_FSR | SPI_NOR_4B_OPCODES) },
+	{ "mt35xu512aba", INFO(0x2c5b1a, 0, 128 * 1024, 512, SECT_4K | USE_FSR | SPI_NOR_OCTAL_READ | SPI_NOR_4B_OPCODES) },
 
 	/* PMC */
 	{ "pm25lv512",   INFO(0,        0, 32 * 1024,    2, SECT_4K_PMC) },
@@ -3199,6 +3201,13 @@ static int spi_nor_init_params(struct spi_nor *nor,
 					  SNOR_PROTO_1_1_4);
 	}
 
+	if (info->flags & SPI_NOR_OCTAL_READ) {
+		params->hwcaps.mask |= SNOR_HWCAPS_READ_1_1_8;
+		spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_1_1_8],
+					  0, 8, SPINOR_OP_READ_1_1_8,
+					  SNOR_PROTO_1_1_8);
+	}
+
 	/* Page Program settings. */
 	params->hwcaps.mask |= SNOR_HWCAPS_PP;
 	spi_nor_set_pp_settings(&params->page_programs[SNOR_CMD_PP],
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 8b1acf68b7ac..ae9861ed7e0f 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -50,6 +50,7 @@
 #define SPINOR_OP_READ_1_2_2	0xbb	/* Read data bytes (Dual I/O SPI) */
 #define SPINOR_OP_READ_1_1_4	0x6b	/* Read data bytes (Quad Output SPI) */
 #define SPINOR_OP_READ_1_4_4	0xeb	/* Read data bytes (Quad I/O SPI) */
+#define SPINOR_OP_READ_1_1_8	0x8b	/* Read data bytes (Octal Output SPI) */
 #define SPINOR_OP_PP		0x02	/* Page program (up to 256 bytes) */
 #define SPINOR_OP_PP_1_1_4	0x32	/* Quad page program */
 #define SPINOR_OP_PP_1_4_4	0x38	/* Quad page program */
@@ -73,6 +74,7 @@
 #define SPINOR_OP_READ_1_2_2_4B	0xbc	/* Read data bytes (Dual I/O SPI) */
 #define SPINOR_OP_READ_1_1_4_4B	0x6c	/* Read data bytes (Quad Output SPI) */
 #define SPINOR_OP_READ_1_4_4_4B	0xec	/* Read data bytes (Quad I/O SPI) */
+#define SPINOR_OP_READ_1_1_8_4B	0x7c	/* Read data bytes (Octal Output SPI) */
 #define SPINOR_OP_PP_4B		0x12	/* Page program (up to 256 bytes) */
 #define SPINOR_OP_PP_1_1_4_4B	0x34	/* Quad page program */
 #define SPINOR_OP_PP_1_4_4_4B	0x3e	/* Quad page program */
-- 
2.19.0