[PATCH v4 16/20] mtd: spi-nor-core: Detect Soft Reset sequence support from BFPT

[Pratyush Yadav]

A Soft Reset sequence will return the flash to Power-on-Reset (POR)
state. It consists of two commands: Soft Reset Enable and Soft Reset.
Find out if the sequence is supported from BFPT DWORD 16.

Signed-off-by: Pratyush Yadav <p.yadav at ti.com>
---
 drivers/mtd/spi/spi-nor-core.c | 6 ++++++
 include/linux/mtd/spi-nor.h    | 1 +
 2 files changed, 7 insertions(+)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index 88aa8268f9..03bf34a3c9 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -151,6 +151,8 @@ struct sfdp_header {
 #define BFPT_DWORD15_QER_SR2_BIT1_NO_RD		(0x4UL << 20)
 #define BFPT_DWORD15_QER_SR2_BIT1		(0x5UL << 20) /* Spansion */
 
+#define BFPT_DWORD16_SOFT_RST			BIT(12)
+
 #define BFPT_DWORD18_CMD_EXT_MASK		GENMASK(30, 29)
 #define BFPT_DWORD18_CMD_EXT_REP		(0x0UL << 29) /* Repeat */
 #define BFPT_DWORD18_CMD_EXT_INV		(0x1UL << 29) /* Invert */
@@ -2073,6 +2075,10 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
 		break;
 	}
 
+	/* Soft Reset support. */
+	if (bfpt.dwords[BFPT_DWORD(16)] & BFPT_DWORD16_SOFT_RST)
+		nor->flags |= SNOR_F_SOFT_RESET;
+
 	/* Stop here if JESD216 rev B. */
 	if (bfpt_header->length == BFPT_DWORD_MAX_JESD216B)
 		return spi_nor_post_bfpt_fixups(nor, bfpt_header, &bfpt,
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index dbd29d0200..0850f1d775 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -248,6 +248,7 @@ enum spi_nor_option_flags {
 	SNOR_F_READY_XSR_RDY	= BIT(4),
 	SNOR_F_USE_CLSR		= BIT(5),
 	SNOR_F_BROKEN_RESET	= BIT(6),
+	SNOR_F_SOFT_RESET	= BIT(7),
 };
 
 struct spi_nor;
-- 
2.26.2