[linux-next RFC v7 2/6] mtd: spi-nor: read JEDEC ID with multiple I/O protocols

[Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>]

When their quad or dual I/O mode is enabled, Micron and Macronix spi-nor
memories don't reply to the regular Read ID (0x9f) command. Instead they
reply to a new dedicated command Read ID Multiple I/O (0xaf).

If the Read ID (0x9f) command fails (the read ID is all 1's or all 0's),
then the Read ID Multiple I/O (0xaf) is used, first with SPI 4-4-4 protocol
(supported by both Micron and Macronix memories), lately with SPI-2-2-2
protocol (supported only by Micron memories).

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>
---
 drivers/mtd/devices/m25p80.c      |  8 +-----
 drivers/mtd/spi-nor/fsl-quadspi.c |  2 +-
 drivers/mtd/spi-nor/nxp-spifi.c   | 13 +++------
 drivers/mtd/spi-nor/spi-nor.c     | 59 ++++++++++++++++++++++++++++++++++-----
 include/linux/mtd/spi-nor.h       | 27 +++++++++++++++---
 5 files changed, 81 insertions(+), 28 deletions(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 4b5d7a4655fd..1457866a4930 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -179,7 +179,6 @@ static int m25p_probe(struct spi_device *spi)
 	struct flash_platform_data	*data;
 	struct m25p *flash;
 	struct spi_nor *nor;
-	enum read_mode mode = SPI_NOR_NORMAL;
 	char *flash_name = NULL;
 	int ret;
 
@@ -205,11 +204,6 @@ static int m25p_probe(struct spi_device *spi)
 	spi_set_drvdata(spi, flash);
 	flash->spi = spi;
 
-	if (spi->mode & SPI_RX_QUAD)
-		mode = SPI_NOR_QUAD;
-	else if (spi->mode & SPI_RX_DUAL)
-		mode = SPI_NOR_DUAL;
-
 	if (data && data->name)
 		nor->mtd.name = data->name;
 
@@ -223,7 +217,7 @@ static int m25p_probe(struct spi_device *spi)
 	else
 		flash_name = spi->modalias;
 
-	ret = spi_nor_scan(nor, flash_name, mode);
+	ret = spi_nor_scan(nor, flash_name, spi->mode);
 	if (ret)
 		return ret;
 
diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 2954f89fc8be..1ded5dbe2240 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -1033,7 +1033,7 @@ static int fsl_qspi_probe(struct platform_device *pdev)
 		/* set the chip address for READID */
 		fsl_qspi_set_base_addr(q, nor);
 
-		ret = spi_nor_scan(nor, NULL, SPI_NOR_QUAD);
+		ret = spi_nor_scan(nor, NULL, SPI_RX_QUAD);
 		if (ret)
 			goto mutex_failed;
 
diff --git a/drivers/mtd/spi-nor/nxp-spifi.c b/drivers/mtd/spi-nor/nxp-spifi.c
index 9e82098ae644..c499f3258245 100644
--- a/drivers/mtd/spi-nor/nxp-spifi.c
+++ b/drivers/mtd/spi-nor/nxp-spifi.c
@@ -272,7 +272,6 @@ static int nxp_spifi_setup_flash(struct nxp_spifi *spifi,
 				 struct device_node *np)
 {
 	struct mtd_part_parser_data ppdata;
-	enum read_mode flash_read;
 	u32 ctrl, property;
 	u16 mode = 0;
 	int ret;
@@ -304,16 +303,12 @@ static int nxp_spifi_setup_flash(struct nxp_spifi *spifi,
 	       SPIFI_CTRL_CSHIGH(15) |
 	       SPIFI_CTRL_FBCLK;
 
-	if (mode & SPI_RX_DUAL) {
+	if (mode & SPI_RX_DUAL)
 		ctrl |= SPIFI_CTRL_DUAL;
-		flash_read = SPI_NOR_DUAL;
-	} else if (mode & SPI_RX_QUAD) {
+	else if (mode & SPI_RX_QUAD)
 		ctrl &= ~SPIFI_CTRL_DUAL;
-		flash_read = SPI_NOR_QUAD;
-	} else {
+	else
 		ctrl |= SPIFI_CTRL_DUAL;
-		flash_read = SPI_NOR_NORMAL;
-	}
 
 	switch (mode & (SPI_CPHA | SPI_CPOL)) {
 	case SPI_MODE_0:
@@ -349,7 +344,7 @@ static int nxp_spifi_setup_flash(struct nxp_spifi *spifi,
 	 */
 	nxp_spifi_dummy_id_read(&spifi->nor);
 
-	ret = spi_nor_scan(&spifi->nor, NULL, flash_read);
+	ret = spi_nor_scan(&spifi->nor, NULL, mode);
 	if (ret) {
 		dev_err(spifi->dev, "device scan failed\n");
 		return ret;
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 8818d4325d20..1908038c8f2e 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -20,6 +20,7 @@
 #include <linux/mtd/cfi.h>
 #include <linux/mtd/mtd.h>
 #include <linux/of_platform.h>
+#include <linux/spi/spi.h>
 #include <linux/spi/flash.h>
 #include <linux/mtd/spi-nor.h>
 
@@ -61,6 +62,11 @@ struct flash_info {
 
 #define JEDEC_MFR(info)	((info)->id[0])
 
+struct read_id_proto {
+	enum spi_protocol	proto;	/* SPI protocol to read the JEDEC ID */
+	u16			mode;	/* SPI controller required caps */
+};
+
 static const struct flash_info *spi_nor_match_id(const char *name);
 
 /*
@@ -701,11 +707,15 @@ static const struct flash_info spi_nor_ids[] = {
 	{ },
 };
 
-static const struct flash_info *spi_nor_read_id(struct spi_nor *nor)
+static const struct flash_info *spi_nor_read_id(struct spi_nor *nor, u16 mode)
 {
-	int			tmp;
+	int			i, tmp;
 	u8			id[SPI_NOR_MAX_ID_LEN];
 	const struct flash_info	*info;
+	static const struct read_id_proto proto[] = {
+		{ SPI_PROTO_4_4_4, SPI_RX_QUAD | SPI_TX_QUAD },
+		{ SPI_PROTO_2_2_2, SPI_RX_DUAL | SPI_TX_DUAL }
+	};
 
 	tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, SPI_NOR_MAX_ID_LEN);
 	if (tmp < 0) {
@@ -713,6 +723,35 @@ static const struct flash_info *spi_nor_read_id(struct spi_nor *nor)
 		return ERR_PTR(tmp);
 	}
 
+	/* Special case for Micron/Macronix qspi nor. */
+	for (i = 0; i < ARRAY_SIZE(proto); ++i) {
+		if (!((id[0] == 0xff && id[1] == 0xff && id[2] == 0xff) ||
+		      (id[0] == 0x00 && id[1] == 0x00 && id[2] == 0x00)))
+			break;
+
+		/* Check whether the SPI controller supports this protocol. */
+		if ((mode & proto[i].mode) != proto[i].mode)
+			continue;
+
+		nor->erase_proto = proto[i].proto;
+		nor->read_proto = proto[i].proto;
+		nor->write_proto = proto[i].proto;
+		nor->reg_proto = proto[i].proto;
+
+		/*
+		 * Multiple I/O Read ID only returns the Manufacturer ID
+		 * (1 byte) and the Device ID (2 bytes). So we reset the
+		 * remaining bytes.
+		 */
+		memset(id, 0, sizeof(id));
+		tmp = nor->read_reg(nor, SPINOR_OP_MIO_RDID, id, 3);
+		if (tmp < 0) {
+			dev_dbg(nor->dev,
+				" error %d reading JEDEC ID (MULTI IO)\n", tmp);
+			return ERR_PTR(tmp);
+		}
+	}
+
 	for (tmp = 0; tmp < ARRAY_SIZE(spi_nor_ids) - 1; tmp++) {
 		info = &spi_nor_ids[tmp];
 		if (info->id_len) {
@@ -999,7 +1038,7 @@ static int spi_nor_check(struct spi_nor *nor)
 	return 0;
 }
 
-int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
+int spi_nor_scan(struct spi_nor *nor, const char *name, u16 mode)
 {
 	const struct flash_info *info = NULL;
 	struct device *dev = nor->dev;
@@ -1012,11 +1051,17 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
 	if (ret)
 		return ret;
 
+	/* Reset SPI protocol for all commands */
+	nor->erase_proto = SPI_PROTO_1_1_1;
+	nor->read_proto = SPI_PROTO_1_1_1;
+	nor->write_proto = SPI_PROTO_1_1_1;
+	nor->reg_proto = SPI_PROTO_1_1_1;
+
 	if (name)
 		info = spi_nor_match_id(name);
 	/* Try to auto-detect if chip name wasn't specified or not found */
 	if (!info)
-		info = spi_nor_read_id(nor);
+		info = spi_nor_read_id(nor, mode);
 	if (IS_ERR_OR_NULL(info))
 		return -ENOENT;
 
@@ -1027,7 +1072,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
 	if (name && info->id_len) {
 		const struct flash_info *jinfo;
 
-		jinfo = spi_nor_read_id(nor);
+		jinfo = spi_nor_read_id(nor, mode);
 		if (IS_ERR(jinfo)) {
 			return PTR_ERR(jinfo);
 		} else if (jinfo != info) {
@@ -1126,14 +1171,14 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
 		nor->flash_read = SPI_NOR_NORMAL;
 
 	/* Quad/Dual-read mode takes precedence over fast/normal */
-	if (mode == SPI_NOR_QUAD && info->flags & SPI_NOR_QUAD_READ) {
+	if (mode & SPI_RX_QUAD && info->flags & SPI_NOR_QUAD_READ) {
 		ret = set_quad_mode(nor, info);
 		if (ret) {
 			dev_err(dev, "quad mode not supported\n");
 			return ret;
 		}
 		nor->flash_read = SPI_NOR_QUAD;
-	} else if (mode == SPI_NOR_DUAL && info->flags & SPI_NOR_DUAL_READ) {
+	} else if (mode & SPI_RX_DUAL && info->flags & SPI_NOR_DUAL_READ) {
 		nor->flash_read = SPI_NOR_DUAL;
 	}
 
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 672595a381c5..32339e82cb9d 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -57,8 +57,9 @@
 #define SPINOR_OP_BRWR		0x17	/* Bank register write */
 
 /* Used for Micron flashes only. */
-#define SPINOR_OP_RD_EVCR      0x65    /* Read EVCR register */
-#define SPINOR_OP_WD_EVCR      0x61    /* Write EVCR register */
+#define SPINOR_OP_MIO_RDID	0xaf	/* Multiple I/O Read JEDEC ID */
+#define SPINOR_OP_RD_EVCR	0x65    /* Read EVCR register */
+#define SPINOR_OP_WD_EVCR	0x61    /* Write EVCR register */
 
 /* Status Register bits. */
 #define SR_WIP			1	/* Write in progress */
@@ -87,6 +88,16 @@ enum read_mode {
 	SPI_NOR_QUAD,
 };
 
+enum spi_protocol {
+	SPI_PROTO_1_1_1,	/* SPI */
+	SPI_PROTO_1_1_2,	/* Dual Output */
+	SPI_PROTO_1_1_4,	/* Quad Output */
+	SPI_PROTO_1_2_2,	/* Dual IO */
+	SPI_PROTO_1_4_4,	/* Quad IO */
+	SPI_PROTO_2_2_2,	/* Dual Command */
+	SPI_PROTO_4_4_4,	/* Quad Command */
+};
+
 #define SPI_NOR_MAX_CMD_SIZE	8
 enum spi_nor_ops {
 	SPI_NOR_OPS_READ = 0,
@@ -117,6 +128,10 @@ struct mtd_info;
  * @flash_read:		the mode of the read
  * @sst_write_second:	used by the SST write operation
  * @flags:		flag options for the current SPI-NOR (SNOR_F_*)
+ * @erase_proto:	the SPI protocol used by erase operations
+ * @read_proto:		the SPI protocol used by read operations
+ * @write_proto:	the SPI protocol used by write operations
+ * @reg_proto		the SPI protocol used by read_reg/write_reg operations
  * @cmd_buf:		used by the write_reg
  * @prepare:		[OPTIONAL] do some preparations for the
  *			read/write/erase/lock/unlock operations
@@ -143,6 +158,10 @@ struct spi_nor {
 	u8			read_opcode;
 	u8			read_dummy;
 	u8			program_opcode;
+	enum spi_protocol	erase_proto;
+	enum spi_protocol	read_proto;
+	enum spi_protocol	write_proto;
+	enum spi_protocol	reg_proto;
 	enum read_mode		flash_read;
 	bool			sst_write_second;
 	u32			flags;
@@ -169,7 +188,7 @@ struct spi_nor {
  * spi_nor_scan() - scan the SPI NOR
  * @nor:	the spi_nor structure
  * @name:	the chip type name
- * @mode:	the read mode supported by the driver
+ * @mode:	the bitmask or TX/RX modes supported by the driver
  *
  * The drivers can use this fuction to scan the SPI NOR.
  * In the scanning, it will try to get all the necessary information to
@@ -179,6 +198,6 @@ struct spi_nor {
  *
  * Return: 0 for success, others for failure.
  */
-int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode);
+int spi_nor_scan(struct spi_nor *nor, const char *name, u16 mode);
 
 #endif
-- 
1.8.2.2

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