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mtd: st_spi_fsm: Add support for JEDEC ID extraction

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Once we start supporting devices it will be handy go detect them
dynamically. This will be done using the chip's unique JEDEC ID. This
patch allows us to extract a device's JEDEC ID using the a predefined
FSM register write sequence.

Acked-by Angus Clark <angus.clark@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
This commit is contained in:
Lee Jones 2014-03-20 09:20:38 +00:00 committed by Brian Norris
parent 030e82dc63
commit 1bd512b562
1 changed files with 55 additions and 0 deletions
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55
drivers/mtd/devices/st_spi_fsm.c
View file

@ -219,6 +219,22 @@ struct stfsm_seq {
uint32_t seq_cfg;
} __packed __aligned(4);
static struct stfsm_seq stfsm_seq_read_jedec = {
.data_size = TRANSFER_SIZE(8),
.seq_opc[0] = (SEQ_OPC_PADS_1 |
SEQ_OPC_CYCLES(8) |
SEQ_OPC_OPCODE(FLASH_CMD_RDID)),
.seq = {
STFSM_INST_CMD1,
STFSM_INST_DATA_READ,
STFSM_INST_STOP,
},
.seq_cfg = (SEQ_CFG_PADS_1 |
SEQ_CFG_READNOTWRITE |
SEQ_CFG_CSDEASSERT |
SEQ_CFG_STARTSEQ),
};
static inline int stfsm_is_idle(struct stfsm *fsm)
{
return readl(fsm->base + SPI_FAST_SEQ_STA) & 0x10;
@ -307,6 +323,42 @@ static void stfsm_read_fifo(struct stfsm *fsm, uint32_t *buf,
}
}
static void stfsm_read_jedec(struct stfsm *fsm, uint8_t *const jedec)
{
const struct stfsm_seq *seq = &stfsm_seq_read_jedec;
uint32_t tmp[2];
stfsm_load_seq(fsm, seq);
stfsm_read_fifo(fsm, tmp, 8);
memcpy(jedec, tmp, 5);
stfsm_wait_seq(fsm);
}
static struct flash_info *stfsm_jedec_probe(struct stfsm *fsm)
{
u16 ext_jedec;
u32 jedec;
u8 id[5];
stfsm_read_jedec(fsm, id);
jedec = id[0] << 16 | id[1] << 8 | id[2];
/*
* JEDEC also defines an optional "extended device information"
* string for after vendor-specific data, after the three bytes
* we use here. Supporting some chips might require using it.
*/
ext_jedec = id[3] << 8 | id[4];
dev_dbg(fsm->dev, "JEDEC = 0x%08x [%02x %02x %02x %02x %02x]\n",
jedec, id[0], id[1], id[2], id[3], id[4]);
return NULL;
}
static int stfsm_set_mode(struct stfsm *fsm, uint32_t mode)
{
int ret, timeout = 10;
@ -436,6 +488,9 @@ static int stfsm_probe(struct platform_device *pdev)
return ret;
}
/* Detect SPI FLASH device */
stfsm_jedec_probe(fsm);
fsm->mtd.dev.parent = &pdev->dev;
fsm->mtd.type = MTD_NORFLASH;
fsm->mtd.writesize = 4;