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

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Submitter Lee Jones
Date Nov. 29, 2013, 12:19 p.m.
Message ID <1385727565-25794-22-git-send-email-lee.jones@linaro.org>
Download mbox | patch
Permalink /patch/295413/
State New
Headers show

Comments

Lee Jones - Nov. 29, 2013, 12:19 p.m.
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(+)

Patch

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
  *