[PATCH 04/15] mtd: st_spi_fsm: Refactor status register operations
From: Lee Jones
Date: Wed Mar 26 2014 - 12:43:49 EST
From: Angus Clark <angus.clark@xxxxxx>
This patch refactors the fsm_read_status() and fsm_write_status() code to
support 1 or 2 byte operations, with a specified command. This allows us to
remove device/register specific code, such as the N25Q fsm_wrvcr() function.
The 'QE' configuration code is updated accordingly, with minor tweaks to ensure
the register values are only written if actually required. One notable change
in this area is that the 'W25Q_STATUS_QE' bit-field is now defined with respect
to the 'SR2' register, rather than the combined 'SR1+SR2' register which is only
used for write operations.
Signed-off-by: Angus Clark <angus.clark@xxxxxx>
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
---
drivers/mtd/devices/st_spi_fsm.c | 152 ++++++++++++++++++---------------------
1 file changed, 68 insertions(+), 84 deletions(-)
diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c
index fabba2c..d6b352e 100644
--- a/drivers/mtd/devices/st_spi_fsm.c
+++ b/drivers/mtd/devices/st_spi_fsm.c
@@ -212,8 +212,6 @@
#define FLASH_CMD_SE_32K 0x52
#define FLASH_CMD_SE 0xd8
#define FLASH_CMD_CHIPERASE 0xc7
-#define FLASH_CMD_WRVCR 0x81
-#define FLASH_CMD_RDVCR 0x85
#define FLASH_CMD_READ 0x03 /* READ */
#define FLASH_CMD_READ_FAST 0x0b /* FAST READ */
@@ -261,6 +259,12 @@
#define S25FL_STATUS_E_ERR 0x20
#define S25FL_STATUS_P_ERR 0x40
+#define N25Q_CMD_WRVCR 0x81
+#define N25Q_CMD_RDVCR 0x85
+#define N25Q_CMD_RDVECR 0x65
+#define N25Q_CMD_RDNVCR 0xb5
+#define N25Q_CMD_WRNVCR 0xb1
+
#define FLASH_PAGESIZE 256 /* In Bytes */
#define FLASH_PAGESIZE_32 (FLASH_PAGESIZE / 4) /* In uint32_t */
#define FLASH_MAX_BUSY_WAIT (300 * HZ) /* Maximum 'CHIPERASE' time */
@@ -592,7 +596,7 @@ static struct seq_rw_config stfsm_s25fl_write4_configs[] = {
/*
* [W25Qxxx] Configuration
*/
-#define W25Q_STATUS_QE (0x1 << 9)
+#define W25Q_STATUS_QE (0x1 << 1)
static struct stfsm_seq stfsm_seq_read_jedec = {
.data_size = TRANSFER_SIZE(8),
@@ -686,23 +690,6 @@ static struct stfsm_seq stfsm_seq_write_status = {
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) |
@@ -890,60 +877,57 @@ static uint8_t stfsm_wait_busy(struct stfsm *fsm)
}
static int stfsm_read_status(struct stfsm *fsm, uint8_t cmd,
- uint8_t *status)
+ uint8_t *data, int bytes)
{
struct stfsm_seq *seq = &stfsm_seq_read_status_fifo;
uint32_t tmp;
+ uint8_t *t = (uint8_t *)&tmp;
+ int i;
- dev_dbg(fsm->dev, "reading STA[%s]\n",
- (cmd == FLASH_CMD_RDSR) ? "1" : "2");
+ dev_dbg(fsm->dev, "read 'status' register [0x%02x], %d byte(s)\n",
+ cmd, bytes);
- seq->seq_opc[0] = (SEQ_OPC_PADS_1 |
- SEQ_OPC_CYCLES(8) |
+ BUG_ON(bytes != 1 && bytes != 2);
+
+ seq->seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
SEQ_OPC_OPCODE(cmd)),
stfsm_load_seq(fsm, seq);
stfsm_read_fifo(fsm, &tmp, 4);
- *status = (uint8_t)(tmp >> 24);
+ for (i = 0; i < bytes; i++)
+ data[i] = t[i];
stfsm_wait_seq(fsm);
return 0;
}
-static int stfsm_write_status(struct stfsm *fsm, uint16_t status,
- int sta_bytes)
+static int stfsm_write_status(struct stfsm *fsm, uint8_t cmd,
+ uint16_t data, int bytes, int wait_busy)
{
struct stfsm_seq *seq = &stfsm_seq_write_status;
- dev_dbg(fsm->dev, "writing STA[%s] 0x%04x\n",
- (sta_bytes == 1) ? "1" : "1+2", status);
-
- seq->status = (uint32_t)status | STA_PADS_1 | STA_CSDEASSERT;
- seq->seq[2] = (sta_bytes == 1) ?
- STFSM_INST_STA_WR1 : STFSM_INST_STA_WR1_2;
-
- stfsm_load_seq(fsm, seq);
-
- stfsm_wait_seq(fsm);
-
- return 0;
-};
+ dev_dbg(fsm->dev,
+ "write 'status' register [0x%02x], %d byte(s), 0x%04x\n"
+ " %s wait-busy\n", cmd, bytes, data, wait_busy ? "with" : "no");
-static int stfsm_wrvcr(struct stfsm *fsm, uint8_t data)
-{
- struct stfsm_seq *seq = &stfsm_seq_wrvcr;
+ BUG_ON(bytes != 1 && bytes != 2);
- dev_dbg(fsm->dev, "writing VCR 0x%02x\n", data);
+ seq->seq_opc[1] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+ SEQ_OPC_OPCODE(cmd));
- seq->status = (STA_DATA_BYTE1(data) | STA_PADS_1 | STA_CSDEASSERT);
+ seq->status = (uint32_t)data | STA_PADS_1 | STA_CSDEASSERT;
+ seq->seq[2] = (bytes == 1) ? STFSM_INST_STA_WR1 : STFSM_INST_STA_WR1_2;
stfsm_load_seq(fsm, seq);
stfsm_wait_seq(fsm);
+ if (wait_busy)
+ stfsm_wait_busy(fsm);
+
return 0;
}
@@ -1163,26 +1147,22 @@ static int stfsm_mx25_config(struct stfsm *fsm)
CFG_ERASESEC_TOGGLE_32BIT_ADDR);
}
- /* Check status of 'QE' bit */
- stfsm_read_status(fsm, FLASH_CMD_RDSR, &sta);
+ /* Check status of 'QE' bit, update if required. */
+ stfsm_read_status(fsm, FLASH_CMD_RDSR, &sta, 1);
data_pads = ((fsm->stfsm_seq_read.seq_cfg >> 16) & 0x3) + 1;
if (data_pads == 4) {
if (!(sta & MX25_STATUS_QE)) {
/* Set 'QE' */
sta |= MX25_STATUS_QE;
- stfsm_write_status(fsm, sta, 1);
-
- stfsm_wait_busy(fsm);
+ stfsm_write_status(fsm, FLASH_CMD_WRSR, sta, 1, 1);
}
} else {
if (sta & MX25_STATUS_QE) {
/* Clear 'QE' */
sta &= ~MX25_STATUS_QE;
- stfsm_write_status(fsm, sta, 1);
-
- stfsm_wait_busy(fsm);
+ stfsm_write_status(fsm, FLASH_CMD_WRSR, sta, 1, 1);
}
}
@@ -1249,7 +1229,7 @@ static int stfsm_n25q_config(struct stfsm *fsm)
*/
vcr = (N25Q_VCR_DUMMY_CYCLES(8) | N25Q_VCR_XIP_DISABLED |
N25Q_VCR_WRAP_CONT);
- stfsm_wrvcr(fsm, vcr);
+ stfsm_write_status(fsm, N25Q_CMD_WRVCR, vcr, 1, 0);
return 0;
}
@@ -1377,6 +1357,7 @@ static int stfsm_s25fl_config(struct stfsm *fsm)
uint32_t offs;
uint16_t sta_wr;
uint8_t sr1, cr1, dyb;
+ int update_sr = 0;
int ret;
if (flags & FLASH_FLAG_32BIT_ADDR) {
@@ -1424,34 +1405,28 @@ static int stfsm_s25fl_config(struct stfsm *fsm)
}
}
- /* Check status of 'QE' bit */
+ /* Check status of 'QE' bit, update if required. */
+ stfsm_read_status(fsm, FLASH_CMD_RDSR2, &cr1, 1);
data_pads = ((fsm->stfsm_seq_read.seq_cfg >> 16) & 0x3) + 1;
- stfsm_read_status(fsm, FLASH_CMD_RDSR2, &cr1);
if (data_pads == 4) {
if (!(cr1 & STFSM_S25FL_CONFIG_QE)) {
/* Set 'QE' */
cr1 |= STFSM_S25FL_CONFIG_QE;
- stfsm_read_status(fsm, FLASH_CMD_RDSR, &sr1);
- sta_wr = ((uint16_t)cr1 << 8) | sr1;
-
- stfsm_write_status(fsm, sta_wr, 2);
-
- stfsm_wait_busy(fsm);
+ update_sr = 1;
}
} else {
- if ((cr1 & STFSM_S25FL_CONFIG_QE)) {
+ if (cr1 & STFSM_S25FL_CONFIG_QE) {
/* Clear 'QE' */
cr1 &= ~STFSM_S25FL_CONFIG_QE;
- stfsm_read_status(fsm, FLASH_CMD_RDSR, &sr1);
- sta_wr = ((uint16_t)cr1 << 8) | sr1;
-
- stfsm_write_status(fsm, sta_wr, 2);
-
- stfsm_wait_busy(fsm);
+ update_sr = 1;
}
-
+ }
+ if (update_sr) {
+ stfsm_read_status(fsm, FLASH_CMD_RDSR, &sr1, 1);
+ sta_wr = ((uint16_t)cr1 << 8) | sr1;
+ stfsm_write_status(fsm, FLASH_CMD_WRSR, sta_wr, 2, 1);
}
/*
@@ -1466,27 +1441,36 @@ static int stfsm_s25fl_config(struct stfsm *fsm)
static int stfsm_w25q_config(struct stfsm *fsm)
{
uint32_t data_pads;
- uint16_t sta_wr;
- uint8_t sta1, sta2;
+ uint8_t sr1, sr2;
+ uint16_t sr_wr;
+ int update_sr = 0;
int ret;
ret = stfsm_prepare_rwe_seqs_default(fsm);
if (ret)
return ret;
- /* If using QUAD mode, set QE STATUS bit */
+ /* Check status of 'QE' bit, update if required. */
+ stfsm_read_status(fsm, FLASH_CMD_RDSR2, &sr2, 1);
data_pads = ((fsm->stfsm_seq_read.seq_cfg >> 16) & 0x3) + 1;
if (data_pads == 4) {
- stfsm_read_status(fsm, FLASH_CMD_RDSR, &sta1);
- stfsm_read_status(fsm, FLASH_CMD_RDSR2, &sta2);
-
- sta_wr = ((uint16_t)sta2 << 8) | sta1;
-
- sta_wr |= W25Q_STATUS_QE;
-
- stfsm_write_status(fsm, sta_wr, 2);
-
- stfsm_wait_busy(fsm);
+ if (!(sr2 & W25Q_STATUS_QE)) {
+ /* Set 'QE' */
+ sr2 |= W25Q_STATUS_QE;
+ update_sr = 1;
+ }
+ } else {
+ if (sr2 & W25Q_STATUS_QE) {
+ /* Clear 'QE' */
+ sr2 &= ~W25Q_STATUS_QE;
+ update_sr = 1;
+ }
+ }
+ if (update_sr) {
+ /* Write status register */
+ stfsm_read_status(fsm, FLASH_CMD_RDSR, &sr1, 1);
+ sr_wr = ((uint16_t)sr2 << 8) | sr1;
+ stfsm_write_status(fsm, FLASH_CMD_WRSR, sr_wr, 2, 1);
}
return 0;
--
1.8.3.2
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