diff options
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/devices/st_spi_fsm.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c index b4afee0e0e33..b1a65c1359d5 100644 --- a/drivers/mtd/devices/st_spi_fsm.c +++ b/drivers/mtd/devices/st_spi_fsm.c @@ -238,6 +238,9 @@ #define FLASH_CMD_READ4_1_1_4 0x6c #define FLASH_CMD_READ4_1_4_4 0xec +#define FLASH_PAGESIZE 256 /* In Bytes */ +#define FLASH_PAGESIZE_32 (FLASH_PAGESIZE / 4) /* In uint32_t */ + /* * Flags to tweak operation of default read/write/erase routines */ @@ -942,6 +945,99 @@ static int stfsm_n25q_config(struct stfsm *fsm) return 0; } +static int stfsm_read(struct stfsm *fsm, uint8_t *buf, uint32_t size, + uint32_t offset) +{ + struct stfsm_seq *seq = &stfsm_seq_read; + uint32_t data_pads; + uint32_t read_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 *p; + + dev_dbg(fsm->dev, "reading %d bytes from 0x%08x\n", size, offset); + + /* Enter 32-bit address mode, if required */ + if (fsm->configuration & CFG_READ_TOGGLE_32BIT_ADDR) + stfsm_enter_32bit_addr(fsm, 1); + + /* Must read in multiples of 32 cycles (or 32*pads/8 Bytes) */ + data_pads = ((seq->seq_cfg >> 16) & 0x3) + 1; + read_mask = (data_pads << 2) - 1; + + /* Handle non-aligned buf */ + p = ((uint32_t)buf & 0x3) ? (uint8_t *)page_buf : buf; + + /* Handle non-aligned size */ + size_ub = (size + read_mask) & ~read_mask; + size_lb = size & ~read_mask; + size_mop = size & read_mask; + + seq->data_size = TRANSFER_SIZE(size_ub); + seq->addr1 = (offset >> 16) & 0xffff; + seq->addr2 = offset & 0xffff; + + stfsm_load_seq(fsm, seq); + + if (size_lb) + stfsm_read_fifo(fsm, (uint32_t *)p, size_lb); + + if (size_mop) { + stfsm_read_fifo(fsm, tmp, read_mask + 1); + memcpy(p + size_lb, &tmp, size_mop); + } + + /* Handle non-aligned buf */ + if ((uint32_t)buf & 0x3) + memcpy(buf, page_buf, size); + + /* Wait for sequence to finish */ + stfsm_wait_seq(fsm); + + stfsm_clear_fifo(fsm); + + /* Exit 32-bit address mode, if required */ + if (fsm->configuration & CFG_READ_TOGGLE_32BIT_ADDR) + stfsm_enter_32bit_addr(fsm, 0); + + return 0; +} + +/* + * Read an address range from the flash chip. The address range + * may be any size provided it is within the physical boundaries. + */ +static int stfsm_mtd_read(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, u_char *buf) +{ + struct stfsm *fsm = dev_get_drvdata(mtd->dev.parent); + uint32_t bytes; + + dev_dbg(fsm->dev, "%s from 0x%08x, len %zd\n", + __func__, (u32)from, len); + + mutex_lock(&fsm->lock); + + while (len > 0) { + bytes = min_t(size_t, len, FLASH_PAGESIZE); + + stfsm_read(fsm, buf, bytes, from); + + buf += bytes; + from += bytes; + len -= bytes; + + *retlen += bytes; + } + + mutex_unlock(&fsm->lock); + + return 0; +} + static void stfsm_read_jedec(struct stfsm *fsm, uint8_t *const jedec) { const struct stfsm_seq *seq = &stfsm_seq_read_jedec; @@ -1197,6 +1293,8 @@ static int stfsm_probe(struct platform_device *pdev) fsm->mtd.size = info->sector_size * info->n_sectors; fsm->mtd.erasesize = info->sector_size; + fsm->mtd._read = stfsm_mtd_read; + dev_err(&pdev->dev, "Found serial flash device: %s\n" " size = %llx (%lldMiB) erasesize = 0x%08x (%uKiB)\n", |