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From:   Pratyush Yadav <me@yadavpratyush.com>
To:     Tudor Ambarus <tudor.ambarus@microchip.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Cc:     Sekhar Nori <nsekhar@ti.com>,
        Boris Brezillon <boris.brezillon@collabora.com>,
        Pratyush Yadav <p.yadav@ti.com>,
        Pratyush Yadav <me@yadavpratyush.com>
Subject: [PATCH v11 09/14] mtd: spi-nor: sfdp: detect Soft Reset sequence support from BFPT
Date:   Thu, 23 Jul 2020 18:41:58 +0530
Message-Id: <20200723131203.40916-10-me@yadavpratyush.com>
In-Reply-To: <20200723131203.40916-1-me@yadavpratyush.com>
References: <20200723131203.40916-1-me@yadavpratyush.com>
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From: Pratyush Yadav <p.yadav@ti.com>

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@ti.com>
---
 drivers/mtd/spi-nor/core.h | 1 +
 drivers/mtd/spi-nor/sfdp.c | 4 ++++
 drivers/mtd/spi-nor/sfdp.h | 2 ++
 3 files changed, 7 insertions(+)

diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 17dbbb3e4796..ec54ce6c5403 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -26,6 +26,7 @@ enum spi_nor_option_flags {
 	SNOR_F_HAS_SR_TB_BIT6	= BIT(11),
 	SNOR_F_HAS_4BIT_BP      = BIT(12),
 	SNOR_F_HAS_SR_BP3_BIT6  = BIT(13),
+	SNOR_F_SOFT_RESET	= BIT(14),
 };
 
 struct spi_nor_read_command {
diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
index 05191f7b3b33..3bd173546cca 100644
--- a/drivers/mtd/spi-nor/sfdp.c
+++ b/drivers/mtd/spi-nor/sfdp.c
@@ -604,6 +604,10 @@ 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 not JESD216 rev C or later. */
 	if (bfpt_header->length == BFPT_DWORD_MAX_JESD216B)
 		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 6d7243067252..8ae55e98084e 100644
--- a/drivers/mtd/spi-nor/sfdp.h
+++ b/drivers/mtd/spi-nor/sfdp.h
@@ -90,6 +90,8 @@ struct sfdp_bfpt {
 #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 */
-- 
2.27.0