From 1bd512b562dde92dae90036c4e6fd91f3870e44f Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Thu, 20 Mar 2014 09:20:38 +0000 Subject: mtd: st_spi_fsm: Add support for JEDEC ID extraction 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 Signed-off-by: Lee Jones Signed-off-by: Brian Norris --- drivers/mtd/devices/st_spi_fsm.c | 55 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) (limited to 'drivers/mtd') diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c index 73e0f2731bcb..9fc0b1911fe1 100644 --- a/drivers/mtd/devices/st_spi_fsm.c +++ b/drivers/mtd/devices/st_spi_fsm.c @@ -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; -- cgit v1.2.3