[PATCH v3 21/36] mtd: st_spi_fsm: Update the flash Volatile Configuration Register

Lee Jones
2013-11-29T12:24:28Z

The FSM Serial Flash Controller is driven by issuing a standard set of
register writes we call a message sequence. This patch supplies a method
to prepare the message sequence responsible for updating a chip's VCR.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
drivers/mtd/devices/st_spi_fsm.c | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)

diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c
index 325fd7a..9449005 100644
--- a/drivers/mtd/devices/st_spi_fsm.c
+++ b/drivers/mtd/devices/st_spi_fsm.c
@@ -68,6 +68,23 @@ static struct stfsm_seq stfsm_seq_erase_sector = {
SEQ_CFG_STARTSEQ),
};

+static struct stfsm_seq stfsm_seq_wrvcr = {
+ .seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+ SEQ_OPC_OPCODE(FLASH_CMD_WREN) | SEQ_OPC_CSDEASSERT),
+ .seq_opc[1] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+ SEQ_OPC_OPCODE(FLASH_CMD_WRVCR)),
+ .seq = {
+ STFSM_INST_CMD1,
+ STFSM_INST_CMD2,
+ STFSM_INST_STA_WR1,
+ STFSM_INST_STOP,
+ },
+ .seq_cfg = (SEQ_CFG_PADS_1 |
+ SEQ_CFG_READNOTWRITE |
+ SEQ_CFG_CSDEASSERT |
+ SEQ_CFG_STARTSEQ),
+};
+
static int stfsm_n25q_en_32bit_addr_seq(struct stfsm_seq *seq)
{
seq->seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
@@ -189,6 +206,21 @@ static int stfsm_enter_32bit_addr(struct stfsm *fsm, int enter)
return 0;
}

+static int stfsm_wrvcr(struct stfsm *fsm, uint8_t data)
+{
+ struct stfsm_seq *seq = &stfsm_seq_wrvcr;
+
+ dev_dbg(fsm->dev, "writing VCR 0x%02x\n", data);
+
+ seq->status = (STA_DATA_BYTE1(data) | STA_PADS_1 | STA_CSDEASSERT);
+
+ stfsm_load_seq(fsm, seq);
+
+ stfsm_wait_seq(fsm);
+
+ return 0;
+}
+
/*
* SoC reset on 'boot-from-spi' systems
*
--
1.8.3.2