[PATCH v4 1/3] mtd: spi-nor: add support for is25wp256

[Sagar Shrikant Kadam]

Update spi_nor_id table for is25wp256 (32MB)device from ISSI,
present on HiFive Unleashed dev board (Rev: A00).

Set method to enable quad mode for ISSI device in flash parameters
table.

Based on code originally written by Wesley Terpstra <wesley@xxxxxxxxxx>
and/or Palmer Dabbelt <palmer@xxxxxxxxxx>
https://github.com/riscv/riscv-linux/commit/c94e267766d62bc9a669611c3d0c8ed5ea26569b

Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@xxxxxxxxxx>
---
 drivers/mtd/spi-nor/spi-nor.c | 10 +++++++++-
 include/linux/mtd/spi-nor.h   |  1 +
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index fae1474..c5408ed 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1834,6 +1834,10 @@ static int sr2_bit7_quad_enable(struct spi_nor *nor)
 			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
 	{ "is25wp128",  INFO(0x9d7018, 0, 64 * 1024, 256,
 			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
+	{ "is25wp256", INFO(0x9d7019, 0, 64 * 1024, 1024,
+			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
+			SPI_NOR_4B_OPCODES)
+	},
 
 	/* Macronix */
 	{ "mx25l512e",   INFO(0xc22010, 0, 64 * 1024,   1, SECT_4K) },
@@ -3650,6 +3654,10 @@ static int spi_nor_init_params(struct spi_nor *nor,
 		case SNOR_MFR_MACRONIX:
 			params->quad_enable = macronix_quad_enable;
 			break;
+		case SNOR_MFR_ISSI:
+			params->quad_enable = macronix_quad_enable;
+			break;
+
 
 		case SNOR_MFR_ST:
 		case SNOR_MFR_MICRON:
@@ -4127,7 +4135,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
 	if (ret)
 		return ret;
 
-	if (nor->addr_width) {
+	if (nor->addr_width && JEDEC_MFR(info) != SNOR_MFR_ISSI) {
 		/* already configured from SFDP */
 	} else if (info->addr_width) {
 		nor->addr_width = info->addr_width;
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index b3d360b..ff13297 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -19,6 +19,7 @@
 #define SNOR_MFR_ATMEL		CFI_MFR_ATMEL
 #define SNOR_MFR_GIGADEVICE	0xc8
 #define SNOR_MFR_INTEL		CFI_MFR_INTEL
+#define SNOR_MFR_ISSI		0x9d		/* ISSI */
 #define SNOR_MFR_ST		CFI_MFR_ST	/* ST Micro */
 #define SNOR_MFR_MICRON		CFI_MFR_MICRON	/* Micron */
 #define SNOR_MFR_MACRONIX	CFI_MFR_MACRONIX
-- 
1.9.1