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From: Pratyush Yadav <p.yadav@ti.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: Boris Brezillon <boris.brezillon@collabora.com>,
	Sekhar Nori <nsekhar@ti.com>, Pratyush Yadav <p.yadav@ti.com>
Subject: [PATCH v15 08/15] mtd: spi-nor: Introduce SNOR_F_IO_MODE_EN_VOLATILE
Date: Fri, 2 Oct 2020 01:50:38 +0530
Message-ID: <20201001202045.21499-9-p.yadav@ti.com> (raw)
In-Reply-To: <20201001202045.21499-1-p.yadav@ti.com>

From: Tudor Ambarus <tudor.ambarus@microchip.com>

We don't want to enter a stateful mode, where a X-X-X I/O mode
is entered by setting a non-volatile bit, because in case of a
reset or a crash, once in the non-volatile mode, we may not be able
to recover in bootloaders and we may break the SPI NOR boot.

Forbid by default the I/O modes that are set via a non-volatile bit.

SPI_NOR_IO_MODE_EN_VOLATILE should be set just for the flashes that
don't define the optional SFDP SCCR Map, so that we don't pollute the
flash info flags.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
---
 drivers/mtd/spi-nor/core.c | 3 +++
 drivers/mtd/spi-nor/core.h | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index b83bf5ed2b2d..e91ddb409699 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -3387,6 +3387,9 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
 	if (info->flags & SPI_NOR_4B_OPCODES)
 		nor->flags |= SNOR_F_4B_OPCODES;
 
+	if (info->flags & SPI_NOR_IO_MODE_EN_VOLATILE)
+		nor->flags |= SNOR_F_IO_MODE_EN_VOLATILE;
+
 	ret = spi_nor_set_addr_width(nor);
 	if (ret)
 		return ret;
diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 9a33c8d07335..eaece1123c0b 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_IO_MODE_EN_VOLATILE = BIT(14),
 };
 
 struct spi_nor_read_command {
@@ -320,6 +321,11 @@ struct flash_info {
 					 */
 #define SPI_NOR_OCTAL_DTR_READ	BIT(19) /* Flash supports octal DTR Read. */
 #define SPI_NOR_OCTAL_DTR_PP	BIT(20) /* Flash supports Octal DTR Page Program */
+#define SPI_NOR_IO_MODE_EN_VOLATILE	BIT(21) /*
+						 * Flash enables the best
+						 * available I/O mode via a
+						 * volatile bit.
+						 */
 
 	/* Part specific fixup hooks. */
 	const struct spi_nor_fixups *fixups;
-- 
2.28.0


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  parent reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-01 20:20 [PATCH v15 00/15] mtd: spi-nor: add xSPI Octal DTR support Pratyush Yadav
2020-10-01 20:20 ` [PATCH v15 01/15] mtd: spi-nor: core: use EOPNOTSUPP instead of ENOTSUPP Pratyush Yadav
2020-10-01 20:20 ` [PATCH v15 02/15] mtd: spi-nor: add spi_nor_controller_ops_{read_reg, write_reg, erase}() Pratyush Yadav
2020-10-01 20:20 ` [PATCH v15 03/15] mtd: spi-nor: add support for DTR protocol Pratyush Yadav
2020-10-01 20:20 ` [PATCH v15 04/15] mtd: spi-nor: sfdp: get command opcode extension type from BFPT Pratyush Yadav
2020-10-01 20:20 ` [PATCH v15 05/15] mtd: spi-nor: sfdp: parse xSPI Profile 1.0 table Pratyush Yadav
2020-10-01 20:20 ` [PATCH v15 06/15] mtd: spi-nor: core: use dummy cycle and address width info from SFDP Pratyush Yadav
2020-10-01 20:20 ` [PATCH v15 07/15] mtd: spi-nor: core: do 2 byte reads for SR and FSR in DTR mode Pratyush Yadav
2020-10-01 20:20 ` Pratyush Yadav [this message]
2020-10-01 20:20 ` [PATCH v15 09/15] mtd: spi-nor: Parse SFDP SCCR Map Pratyush Yadav
2020-10-01 20:20 ` [PATCH v15 10/15] mtd: spi-nor: core: enable octal DTR mode when possible Pratyush Yadav
2020-10-02  9:47   ` Tudor.Ambarus
2020-10-01 20:20 ` [PATCH v15 11/15] mtd: spi-nor: sfdp: detect Soft Reset sequence support from BFPT Pratyush Yadav
2020-10-01 20:20 ` [PATCH v15 12/15] mtd: spi-nor: core: perform a Soft Reset on shutdown Pratyush Yadav
2020-10-01 20:20 ` [PATCH v15 13/15] mtd: spi-nor: core: disable Octal DTR mode on suspend Pratyush Yadav
2020-10-01 20:20 ` [PATCH v15 14/15] mtd: spi-nor: spansion: add support for Cypress Semper flash Pratyush Yadav
2020-10-03 11:40   ` Vignesh Raghavendra
2020-10-01 20:20 ` [PATCH v15 15/15] mtd: spi-nor: micron-st: allow using MT35XU512ABA in Octal DTR mode Pratyush Yadav

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