Messages in this thread Patch in this message |  | | From | Lee Jones <> | Subject | [PATCH 07/10] mtd: st_spi_fsm: Add support for JEDEC ID extraction | Date | Thu, 14 Nov 2013 14:22:33 +0000 |
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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.
Signed-off-by: Lee Jones <lee.jones@linaro.org> --- drivers/mtd/devices/st_spi_fsm.c | 63 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+)
diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c index 6691eaf..2899e0f 100644 --- a/drivers/mtd/devices/st_spi_fsm.c +++ b/drivers/mtd/devices/st_spi_fsm.c @@ -92,6 +92,22 @@ struct stfsm_seq { } __attribute__((__packed__, aligned(4))); #define STFSM_SEQ_SIZE sizeof(struct stfsm_seq) +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; @@ -158,6 +174,50 @@ static void stfsm_read_fifo(struct stfsm *fsm, uint32_t *buf, } } +static int 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); + + return 0; +} + +static struct flash_info * stfsm_jedec_probe(struct stfsm *fsm) +{ + u16 ext_jedec; + u32 jedec; + u8 id[5]; + int ret; + + /* + * 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. + */ + + ret = stfsm_read_jedec(fsm, id); + if (ret) { + dev_info(fsm->dev, "Error reading JEDEC ID\n"); + return NULL; + } + + jedec = id[0] << 16 | id[1] << 8 | id[2]; + 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 void stfsm_clear_fifo(struct stfsm *fsm) { uint32_t avail; @@ -310,6 +370,9 @@ static int stfsm_probe(struct platform_device *pdev) return ret; } + /* Detect SPI FLASH device */ + stfsm_jedec_probe(fsm); + platform_set_drvdata(pdev, fsm); fsm->mtd.dev.parent = &pdev->dev; -- 1.8.1.2
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