[PATCH 20/23] mtd: st_spi_fsm: Provide a method to put the chip into 32bit addressing mode

[Lee Jones]

Most Serial Flash chips support 24bit addressing as a default but more
recent incarnations can support 32bit. Based on information provided
though platform specific data and capabilities we can determine whether
or not our current chip can. This patch provides a means to setup the
FSM message sequence to put the chip into 32bit mode.

Signed-off-by: Lee Jones <lee.jones at linaro.org>
---
 drivers/mtd/devices/st_spi_fsm.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c
index 9a66c99..b99b4c1 100644
--- a/drivers/mtd/devices/st_spi_fsm.c
+++ b/drivers/mtd/devices/st_spi_fsm.c
@@ -28,6 +28,8 @@
 #include "st_spi_fsm.h"
 #include "serial_flash_cmds.h"
 
+static struct stfsm_seq stfsm_seq_en_32bit_addr;/* Dynamically populated */
+
 static struct stfsm_seq stfsm_seq_read_jedec = {
 	.data_size = TRANSFER_SIZE(8),
 	.seq_opc[0] = (SEQ_OPC_PADS_1 |
@@ -128,6 +130,23 @@ static void stfsm_wait_seq(struct stfsm *fsm)
 	dev_err(fsm->dev, "timeout on sequence completion\n");
 }
 
+static int stfsm_enter_32bit_addr(struct stfsm *fsm, int enter)
+{
+	struct stfsm_seq *seq = &stfsm_seq_en_32bit_addr;
+	uint32_t cmd = enter ? FLASH_CMD_EN4B_ADDR : FLASH_CMD_EX4B_ADDR;
+
+	seq->seq_opc[0] = (SEQ_OPC_PADS_1 |
+			   SEQ_OPC_CYCLES(8) |
+			   SEQ_OPC_OPCODE(cmd) |
+			   SEQ_OPC_CSDEASSERT);
+
+	stfsm_load_seq(fsm, seq);
+
+	stfsm_wait_seq(fsm);
+
+	return 0;
+}
+
 /*
  * SoC reset on 'boot-from-spi' systems
  *
-- 
1.8.1.2