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Subject[PATCH linux-next v6 1/8] mtd: spi-nor: read JEDEC ID with multiple I/O protocols
Date
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@atmel.com>
---
drivers/mtd/spi-nor/spi-nor.c | 28 +++++++++++++++++++++++++++-
include/linux/mtd/spi-nor.h | 23 +++++++++++++++++++++--
2 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index f59aedfe1462..80a0db078aaa 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -703,8 +703,9 @@ static const struct flash_info spi_nor_ids[] = {

static const struct flash_info *spi_nor_read_id(struct spi_nor *nor)
{
- int tmp;
+ int i, tmp;
u8 id[SPI_NOR_MAX_ID_LEN];
+ enum spi_protocol proto[2] = {SPI_PROTO_4_4_4, SPI_PROTO_2_2_2};
const struct flash_info *info;

tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, SPI_NOR_MAX_ID_LEN);
@@ -713,6 +714,25 @@ 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;
+
+ nor->erase_proto = proto[i];
+ nor->read_proto = proto[i];
+ nor->write_proto = proto[i];
+ nor->reg_proto = proto[i];
+ tmp = nor->read_reg(nor, SPINOR_OP_MIO_RDID,
+ id, SPI_NOR_MAX_ID_LEN);
+ 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) {
@@ -1013,6 +1033,12 @@ 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 */
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index e5409524bb0a..66a5f144728a 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 */
+};
+
/**
* struct spi_nor_xfer_cfg - Structure for defining a Serial Flash transfer
* @wren: command for "Write Enable", or 0x00 for not required
@@ -142,6 +153,10 @@ enum spi_nor_option_flags {
* @sst_write_second: used by the SST write operation
* @flags: flag options for the current SPI-NOR (SNOR_F_*)
* @cfg: used by the read_xfer/write_xfer
+ * @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
@@ -169,6 +184,10 @@ 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;
--
1.8.2.2


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