[PATCH v3 13/36] mtd: st_spi_fsm: Prepare the read/write FSM message sequence(s)

Lee Jones
2013-11-29T12:20:07Z

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 read/write FSM message sequence(s) based on chip capability
and configuration.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
drivers/mtd/devices/st_spi_fsm.c | 69 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 69 insertions(+)

diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c
index 1f54983..e04de62 100644
--- a/drivers/mtd/devices/st_spi_fsm.c
+++ b/drivers/mtd/devices/st_spi_fsm.c
@@ -139,6 +139,75 @@ stfsm_search_seq_rw_configs(struct stfsm *fsm,
return NULL;
}

+/* Prepare a READ/WRITE sequence according to configuration parameters */
+static void stfsm_prepare_rw_seq(struct stfsm *fsm,
+ struct stfsm_seq *seq,
+ struct seq_rw_config *cfg)
+{
+ int addr1_cycles, addr2_cycles;
+ int i = 0;
+
+ memset(seq, 0, STFSM_SEQ_SIZE);
+
+ /* Add READ/WRITE OPC */
+ seq->seq_opc[i++] = (SEQ_OPC_PADS_1 |
+ SEQ_OPC_CYCLES(8) |
+ SEQ_OPC_OPCODE(cfg->cmd));
+
+ /* Add WREN OPC for a WRITE sequence */
+ if (cfg->write)
+ seq->seq_opc[i++] = (SEQ_OPC_PADS_1 |
+ SEQ_OPC_CYCLES(8) |
+ SEQ_OPC_OPCODE(FLASH_CMD_WREN) |
+ SEQ_OPC_CSDEASSERT);
+
+ /* Address configuration (24 or 32-bit addresses) */
+ addr1_cycles = (fsm->info->flags & FLASH_FLAG_32BIT_ADDR) ? 16 : 8;
+ addr1_cycles /= cfg->addr_pads;
+ addr2_cycles = 16 / cfg->addr_pads;
+ seq->addr_cfg = ((addr1_cycles & 0x3f) << 0 | /* ADD1 cycles */
+ (cfg->addr_pads - 1) << 6 | /* ADD1 pads */
+ (addr2_cycles & 0x3f) << 16 | /* ADD2 cycles */
+ ((cfg->addr_pads - 1) << 22)); /* ADD2 pads */
+
+ /* Data/Sequence configuration */
+ seq->seq_cfg = ((cfg->data_pads - 1) << 16 |
+ SEQ_CFG_STARTSEQ |
+ SEQ_CFG_CSDEASSERT);
+ if (!cfg->write)
+ seq->seq_cfg |= SEQ_CFG_READNOTWRITE;
+
+ /* Mode configuration (no. of pads taken from addr cfg) */
+ seq->mode = ((cfg->mode_data & 0xff) << 0 | /* data */
+ (cfg->mode_cycles & 0x3f) << 16 | /* cycles */
+ (cfg->addr_pads - 1) << 22); /* pads */
+
+ /* Dummy configuration (no. of pads taken from addr cfg) */
+ seq->dummy = ((cfg->dummy_cycles & 0x3f) << 16 | /* cycles */
+ (cfg->addr_pads - 1) << 22); /* pads */
+
+
+ /* Instruction sequence */
+ i = 0;
+ if (cfg->write)
+ seq->seq[i++] = STFSM_INST_CMD2;
+
+ seq->seq[i++] = STFSM_INST_CMD1;
+
+ seq->seq[i++] = STFSM_INST_ADD1;
+ seq->seq[i++] = STFSM_INST_ADD2;
+
+ if (cfg->mode_cycles)
+ seq->seq[i++] = STFSM_INST_MODE;
+
+ if (cfg->dummy_cycles)
+ seq->seq[i++] = STFSM_INST_DUMMY;
+
+ seq->seq[i++] =
+ cfg->write ? STFSM_INST_DATA_WRITE : STFSM_INST_DATA_READ;
+ seq->seq[i++] = STFSM_INST_STOP;
+}
+
static void stfsm_read_jedec(struct stfsm *fsm, uint8_t *const jedec)
{
const struct stfsm_seq *seq = &stfsm_seq_read_jedec;
--
1.8.3.2