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Subject[PATCH linux-next v2 02/14] mtd: spi-nor: properly detect the memory when it boots in Quad or Dual mode
Date
The quad (or dual) mode of a spi-nor memory may be enabled at boot time by
non-volatile bits in some setting register. Also such a mode may have
already been enabled at early stage by some boot loader.

Hence, we should not guess the spi-nor memory is always configured for the
regular SPI 1-1-1 protocol.

Micron and Macronix memories, once their Quad (or dual for Micron) mode
enabled, no longer process the regular JEDEC Read ID (0x9f) command but
instead reply to a new command: JEDEC Read ID Multiple I/O (0xaf).
Besides, in Quad mode both memory manufacturers expect ALL commands to
use the SPI 4-4-4 protocol. For Micron memories, enabling their Dual mode
implies to use the SPI 2-2-2 protocol for ALL commands.

Winbond memories, once their Quad mode enabled, expect ALL commands to use
the SPI 4-4-4 protocol. Unlike Micron and Macronix memories, they still
reply to the regular JEDEC Read ID (0x9f) command.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
---
drivers/mtd/spi-nor/spi-nor.c | 83 ++++++++++++++++++++++++++++++++++++++++---
include/linux/mtd/spi-nor.h | 50 ++++++++++++++++++++++++--
2 files changed, 127 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 3028c06547c1..8967319ea7da 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -73,6 +73,12 @@ struct flash_info {

#define JEDEC_MFR(info) ((info)->id[0])

+struct read_id_config {
+ enum read_mode mode;
+ enum spi_nor_protocol proto;
+ u8 opcode;
+};
+
static const struct flash_info *spi_nor_match_id(const char *name);

/*
@@ -879,11 +885,22 @@ 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,
+ enum read_mode mode)
{
- int tmp;
+ int i, tmp;
u8 id[SPI_NOR_MAX_ID_LEN];
const struct flash_info *info;
+ static const struct read_id_config configs[] = {
+ /* Winbond QPI mode */
+ {SPI_NOR_QUAD, SNOR_PROTO_4_4_4, SPINOR_OP_RDID},
+
+ /* Micron Quad mode & Macronix QPI mode */
+ {SPI_NOR_QUAD, SNOR_PROTO_4_4_4, SPINOR_OP_MIO_RDID},
+
+ /* Micron Dual mode */
+ {SPI_NOR_DUAL, SNOR_PROTO_2_2_2, SPINOR_OP_MIO_RDID}
+ };

tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, SPI_NOR_MAX_ID_LEN);
if (tmp < 0) {
@@ -891,6 +908,58 @@ static const struct flash_info *spi_nor_read_id(struct spi_nor *nor)
return ERR_PTR(tmp);
}

+ /*
+ * Check whether the SPI NOR memory has already been configured (at
+ * reset or by some bootloader) to use a protocol other than SPI 1-1-1.
+ */
+ for (i = 0; i < ARRAY_SIZE(configs); ++i) {
+ int len = SPI_NOR_MAX_ID_LEN;
+ bool is_multi = false;
+
+ /*
+ * Check the latest read Manufacturer ID + Device ID (3 bytes):
+ * if they are different from both 0x000000 and 0xffffff, we
+ * assume that we succeeded in reading a valid JEDEC ID so we
+ * don't need to try other SPI protocols.
+ * Indeed when either the protocol or the op code are not valid,
+ * the SPI NOR memory should not reply to the command. Hence the
+ * SPI I/O lines remain in their default state: 1 when connected
+ * to pull-up resistors or 0 with pull-down.
+ */
+ if (!((id[0] == 0xff && id[1] == 0xff && id[2] == 0xff) ||
+ (id[0] == 0x00 && id[1] == 0x00 && id[2] == 0x00)))
+ break;
+
+ /* Only try protocols supported by the user. */
+ if (configs[i].mode != mode)
+ continue;
+
+ /* Set this protocol for all commands. */
+ nor->reg_proto = configs[i].proto;
+ nor->read_proto = configs[i].proto;
+ nor->write_proto = configs[i].proto;
+ nor->erase_proto = configs[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.
+ */
+ if (configs[i].opcode == SPINOR_OP_MIO_RDID) {
+ is_multi = true;
+ len = 3;
+ memset(id + len, 0, sizeof(id) - len);
+ }
+
+ tmp = nor->read_reg(nor, configs[i].opcode, id, len);
+ if (tmp < 0) {
+ dev_dbg(nor->dev,
+ "error %d reading JEDEC ID%s\n",
+ tmp, (is_multi ? " Multi I/O" : ""));
+ return ERR_PTR(tmp);
+ }
+ }
+
for (tmp = 0; tmp < ARRAY_SIZE(spi_nor_ids) - 1; tmp++) {
info = &spi_nor_ids[tmp];
if (info->id_len) {
@@ -1148,11 +1217,17 @@ 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 = SNOR_PROTO_1_1_1;
+ nor->read_proto = SNOR_PROTO_1_1_1;
+ nor->write_proto = SNOR_PROTO_1_1_1;
+ nor->reg_proto = SNOR_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;

@@ -1163,7 +1238,7 @@ 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) {
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 62356d50815b..53932c87bcf2 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -75,8 +75,9 @@
#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 BIT(0) /* Write in progress */
@@ -105,6 +106,43 @@ enum read_mode {
SPI_NOR_QUAD,
};

+
+#define SNOR_PROTO_CMD_OFF 8
+#define SNOR_PROTO_CMD_MASK GENMASK(11, 8)
+#define SNOR_PROTO_CMD_TO_PROTO(cmd) \
+ (((cmd) << SNOR_PROTO_CMD_OFF) & SNOR_PROTO_CMD_MASK)
+#define SNOR_PROTO_CMD_FROM_PROTO(proto) \
+ ((((u32)(proto)) & SNOR_PROTO_CMD_MASK) >> SNOR_PROTO_CMD_OFF)
+
+#define SNOR_PROTO_ADDR_OFF 4
+#define SNOR_PROTO_ADDR_MASK GENMASK(7, 4)
+#define SNOR_PROTO_ADDR_TO_PROTO(addr) \
+ (((addr) << SNOR_PROTO_ADDR_OFF) & SNOR_PROTO_ADDR_MASK)
+#define SNOR_PROTO_ADDR_FROM_PROTO(proto) \
+ ((((u32)(proto)) & SNOR_PROTO_ADDR_MASK) >> SNOR_PROTO_ADDR_OFF)
+
+#define SNOR_PROTO_DATA_OFF 0
+#define SNOR_PROTO_DATA_MASK GENMASK(3, 0)
+#define SNOR_PROTO_DATA_TO_PROTO(data) \
+ (((data) << SNOR_PROTO_DATA_OFF) & SNOR_PROTO_DATA_MASK)
+#define SNOR_PROTO_DATA_FROM_PROTO(proto) \
+ ((((u32)(proto)) & SNOR_PROTO_DATA_MASK) >> SNOR_PROTO_DATA_OFF)
+
+#define SNOR_PROTO(cmd, addr, data) \
+ (SNOR_PROTO_CMD_TO_PROTO(cmd) | \
+ SNOR_PROTO_ADDR_TO_PROTO(addr) | \
+ SNOR_PROTO_DATA_TO_PROTO(data))
+
+enum spi_nor_protocol {
+ SNOR_PROTO_1_1_1 = SNOR_PROTO(1, 1, 1), /* SPI */
+ SNOR_PROTO_1_1_2 = SNOR_PROTO(1, 1, 2), /* Dual Output */
+ SNOR_PROTO_1_1_4 = SNOR_PROTO(1, 1, 4), /* Quad Output */
+ SNOR_PROTO_1_2_2 = SNOR_PROTO(1, 2, 2), /* Dual IO */
+ SNOR_PROTO_1_4_4 = SNOR_PROTO(1, 4, 4), /* Quad IO */
+ SNOR_PROTO_2_2_2 = SNOR_PROTO(2, 2, 2), /* Dual Command */
+ SNOR_PROTO_4_4_4 = SNOR_PROTO(4, 4, 4), /* Quad Command */
+};
+
#define SPI_NOR_MAX_CMD_SIZE 8
enum spi_nor_ops {
SPI_NOR_OPS_READ = 0,
@@ -132,6 +170,10 @@ enum spi_nor_option_flags {
* @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
@@ -160,6 +202,10 @@ struct spi_nor {
u8 read_opcode;
u8 read_dummy;
u8 program_opcode;
+ enum spi_nor_protocol erase_proto;
+ enum spi_nor_protocol read_proto;
+ enum spi_nor_protocol write_proto;
+ enum spi_nor_protocol reg_proto;
enum read_mode flash_read;
bool sst_write_second;
u32 flags;
--
1.8.2.2
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