[PATCH v6 27/36] mtd: st_spi_fsm: Supply a busy wait for post-write status
Lee Jones
lee.jones at linaro.org
Thu Mar 20 05:20:59 EDT 2014
When we write data to the Serial Flash chip we'll wait a predetermined
period of time before giving up. During that period of time we poll the
status register until completion.
Acked-by Angus Clark <angus.clark at st.com>
Signed-off-by: Lee Jones <lee.jones at linaro.org>
---
drivers/mtd/devices/st_spi_fsm.c | 221 +++++++++++++++++++++++++++++++++++++++
1 file changed, 221 insertions(+)
diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c
index 58b8761..99e08b0 100644
--- a/drivers/mtd/devices/st_spi_fsm.c
+++ b/drivers/mtd/devices/st_spi_fsm.c
@@ -238,8 +238,18 @@
#define FLASH_CMD_READ4_1_1_4 0x6c
#define FLASH_CMD_READ4_1_4_4 0xec
+/* Status register */
+#define FLASH_STATUS_BUSY 0x01
+#define FLASH_STATUS_WEL 0x02
+#define FLASH_STATUS_BP0 0x04
+#define FLASH_STATUS_BP1 0x08
+#define FLASH_STATUS_BP2 0x10
+#define FLASH_STATUS_SRWP0 0x80
+#define FLASH_STATUS_TIMEOUT 0xff
+
#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 */
/*
* Flags to tweak operation of default read/write/erase routines
@@ -519,6 +529,22 @@ static struct stfsm_seq stfsm_seq_read_jedec = {
SEQ_CFG_STARTSEQ),
};
+static struct stfsm_seq stfsm_seq_read_status_fifo = {
+ .data_size = TRANSFER_SIZE(4),
+ .seq_opc[0] = (SEQ_OPC_PADS_1 |
+ SEQ_OPC_CYCLES(8) |
+ SEQ_OPC_OPCODE(FLASH_CMD_RDSR)),
+ .seq = {
+ STFSM_INST_CMD1,
+ STFSM_INST_DATA_READ,
+ STFSM_INST_STOP,
+ },
+ .seq_cfg = (SEQ_CFG_PADS_1 |
+ SEQ_CFG_READNOTWRITE |
+ SEQ_CFG_CSDEASSERT |
+ SEQ_CFG_STARTSEQ),
+};
+
static struct stfsm_seq stfsm_seq_erase_sector = {
/* 'addr_cfg' configured during initialisation */
.seq_opc = {
@@ -699,6 +725,53 @@ static int stfsm_enter_32bit_addr(struct stfsm *fsm, int enter)
return 0;
}
+static uint8_t stfsm_wait_busy(struct stfsm *fsm)
+{
+ struct stfsm_seq *seq = &stfsm_seq_read_status_fifo;
+ unsigned long deadline;
+ uint32_t status;
+ int timeout = 0;
+
+ /* Use RDRS1 */
+ seq->seq_opc[0] = (SEQ_OPC_PADS_1 |
+ SEQ_OPC_CYCLES(8) |
+ SEQ_OPC_OPCODE(FLASH_CMD_RDSR));
+
+ /* Load read_status sequence */
+ stfsm_load_seq(fsm, seq);
+
+ /*
+ * Repeat until busy bit is deasserted, or timeout, or error (S25FLxxxS)
+ */
+ deadline = jiffies + FLASH_MAX_BUSY_WAIT;
+ while (!timeout) {
+ cond_resched();
+
+ if (time_after_eq(jiffies, deadline))
+ timeout = 1;
+
+ stfsm_wait_seq(fsm);
+
+ stfsm_read_fifo(fsm, &status, 4);
+
+ if ((status & FLASH_STATUS_BUSY) == 0)
+ return 0;
+
+ if ((fsm->configuration & CFG_S25FL_CHECK_ERROR_FLAGS) &&
+ ((status & S25FL_STATUS_P_ERR) ||
+ (status & S25FL_STATUS_E_ERR)))
+ return (uint8_t)(status & 0xff);
+
+ if (!timeout)
+ /* Restart */
+ writel(seq->seq_cfg, fsm->base + SPI_FAST_SEQ_CFG);
+ }
+
+ dev_err(fsm->dev, "timeout on wait_busy\n");
+
+ return FLASH_STATUS_TIMEOUT;
+}
+
static int stfsm_wrvcr(struct stfsm *fsm, uint8_t data)
{
struct stfsm_seq *seq = &stfsm_seq_wrvcr;
@@ -1020,6 +1093,98 @@ static int stfsm_read(struct stfsm *fsm, uint8_t *buf, uint32_t size,
return 0;
}
+static int stfsm_write(struct stfsm *fsm, const uint8_t *const buf,
+ const uint32_t size, const uint32_t offset)
+{
+ struct stfsm_seq *seq = &stfsm_seq_write;
+ uint32_t data_pads;
+ uint32_t write_mask;
+ uint32_t size_ub;
+ uint32_t size_lb;
+ uint32_t size_mop;
+ uint32_t tmp[4];
+ uint32_t page_buf[FLASH_PAGESIZE_32];
+ uint8_t *t = (uint8_t *)&tmp;
+ const uint8_t *p;
+ int ret;
+ int i;
+
+ dev_dbg(fsm->dev, "writing %d bytes to 0x%08x\n", size, offset);
+
+ /* Enter 32-bit address mode, if required */
+ if (fsm->configuration & CFG_WRITE_TOGGLE_32BIT_ADDR)
+ stfsm_enter_32bit_addr(fsm, 1);
+
+ /* Must write in multiples of 32 cycles (or 32*pads/8 bytes) */
+ data_pads = ((seq->seq_cfg >> 16) & 0x3) + 1;
+ write_mask = (data_pads << 2) - 1;
+
+ /* Handle non-aligned buf */
+ if ((uint32_t)buf & 0x3) {
+ memcpy(page_buf, buf, size);
+ p = (uint8_t *)page_buf;
+ } else {
+ p = buf;
+ }
+
+ /* Handle non-aligned size */
+ size_ub = (size + write_mask) & ~write_mask;
+ size_lb = size & ~write_mask;
+ size_mop = size & write_mask;
+
+ seq->data_size = TRANSFER_SIZE(size_ub);
+ seq->addr1 = (offset >> 16) & 0xffff;
+ seq->addr2 = offset & 0xffff;
+
+ /* Need to set FIFO to write mode, before writing data to FIFO (see
+ * GNBvb79594)
+ */
+ writel(0x00040000, fsm->base + SPI_FAST_SEQ_CFG);
+
+ /*
+ * Before writing data to the FIFO, apply a small delay to allow a
+ * potential change of FIFO direction to complete.
+ */
+ if (fsm->fifo_dir_delay == 0)
+ readl(fsm->base + SPI_FAST_SEQ_CFG);
+ else
+ udelay(fsm->fifo_dir_delay);
+
+
+ /* Write data to FIFO, before starting sequence (see GNBvd79593) */
+ if (size_lb) {
+ stfsm_write_fifo(fsm, (uint32_t *)p, size_lb);
+ p += size_lb;
+ }
+
+ /* Handle non-aligned size */
+ if (size_mop) {
+ memset(t, 0xff, write_mask + 1); /* fill with 0xff's */
+ for (i = 0; i < size_mop; i++)
+ t[i] = *p++;
+
+ stfsm_write_fifo(fsm, tmp, write_mask + 1);
+ }
+
+ /* Start sequence */
+ stfsm_load_seq(fsm, seq);
+
+ /* Wait for sequence to finish */
+ stfsm_wait_seq(fsm);
+
+ /* Wait for completion */
+ ret = stfsm_wait_busy(fsm);
+
+ /* Exit 32-bit address mode, if required */
+ if (fsm->configuration & CFG_WRITE_TOGGLE_32BIT_ADDR) {
+ stfsm_enter_32bit_addr(fsm, 0);
+ if (fsm->configuration & CFG_WRITE_EX_32BIT_ADDR_DELAY)
+ udelay(1);
+ }
+
+ return 0;
+}
+
/*
* Read an address range from the flash chip. The address range
* may be any size provided it is within the physical boundaries.
@@ -1052,6 +1217,61 @@ static int stfsm_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
return 0;
}
+/*
+ * Write an address range to the flash chip. Data must be written in
+ * FLASH_PAGESIZE chunks. The address range may be any size provided
+ * it is within the physical boundaries.
+ */
+static int stfsm_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, const u_char *buf)
+{
+ struct stfsm *fsm = dev_get_drvdata(mtd->dev.parent);
+
+ u32 page_offs;
+ u32 bytes;
+ uint8_t *b = (uint8_t *)buf;
+ int ret = 0;
+
+ dev_dbg(fsm->dev, "%s to 0x%08x, len %zd\n", __func__, (u32)to, len);
+
+ *retlen = 0;
+
+ if (!len)
+ return 0;
+
+ if (to + len > mtd->size)
+ return -EINVAL;
+
+ /* Offset within page */
+ page_offs = to % FLASH_PAGESIZE;
+
+ mutex_lock(&fsm->lock);
+
+ while (len) {
+ /* Write up to page boundary */
+ bytes = min(FLASH_PAGESIZE - page_offs, len);
+
+ ret = stfsm_write(fsm, b, bytes, to);
+ if (ret)
+ goto out1;
+
+ b += bytes;
+ len -= bytes;
+ to += bytes;
+
+ /* We are now page-aligned */
+ page_offs = 0;
+
+ *retlen += bytes;
+
+ }
+
+out1:
+ mutex_unlock(&fsm->lock);
+
+ return ret;
+}
+
static void stfsm_read_jedec(struct stfsm *fsm, uint8_t *const jedec)
{
const struct stfsm_seq *seq = &stfsm_seq_read_jedec;
@@ -1308,6 +1528,7 @@ static int stfsm_probe(struct platform_device *pdev)
fsm->mtd.erasesize = info->sector_size;
fsm->mtd._read = stfsm_mtd_read;
+ fsm->mtd._write = stfsm_mtd_write;
dev_err(&pdev->dev,
"Found serial flash device: %s\n"
--
1.8.3.2
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