diff options
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/spi-nor/spi-nor.c | 70 |
1 files changed, 63 insertions, 7 deletions
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index d1edafc51cbb..2aebf18f7c36 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -70,6 +70,11 @@ struct flash_info { #define SPI_NOR_QUAD_READ BIT(6) /* Flash supports Quad Read */ #define USE_FSR BIT(7) /* use flag status register */ #define SPI_NOR_HAS_LOCK BIT(8) /* Flash supports lock/unlock via SR */ +#define SPI_NOR_HAS_TB BIT(9) /* + * Flash SR has Top/Bottom (TB) protect + * bit. Must be used with + * SPI_NOR_HAS_LOCK. + */ }; #define JEDEC_MFR(info) ((info)->id[0]) @@ -435,7 +440,10 @@ static void stm_get_locked_range(struct spi_nor *nor, u8 sr, loff_t *ofs, } else { pow = ((sr & mask) ^ mask) >> shift; *len = mtd->size >> pow; - *ofs = mtd->size - *len; + if (nor->flags & SNOR_F_HAS_SR_TB && sr & SR_TB) + *ofs = 0; + else + *ofs = mtd->size - *len; } } @@ -476,12 +484,14 @@ static int stm_is_unlocked_sr(struct spi_nor *nor, loff_t ofs, uint64_t len, /* * Lock a region of the flash. Compatible with ST Micro and similar flash. - * Supports only the block protection bits BP{0,1,2} in the status register + * Supports the block protection bits BP{0,1,2} in the status register * (SR). Does not support these features found in newer SR bitfields: - * - TB: top/bottom protect - only handle TB=0 (top protect) * - SEC: sector/block protect - only handle SEC=0 (block protect) * - CMP: complement protect - only support CMP=0 (range is not complemented) * + * Support for the following is provided conditionally for some flash: + * - TB: top/bottom protect + * * Sample table portion for 8MB flash (Winbond w25q64fw): * * SEC | TB | BP2 | BP1 | BP0 | Prot Length | Protected Portion @@ -494,6 +504,13 @@ static int stm_is_unlocked_sr(struct spi_nor *nor, loff_t ofs, uint64_t len, * 0 | 0 | 1 | 0 | 1 | 2 MB | Upper 1/4 * 0 | 0 | 1 | 1 | 0 | 4 MB | Upper 1/2 * X | X | 1 | 1 | 1 | 8 MB | ALL + * ------|-------|-------|-------|-------|---------------|------------------- + * 0 | 1 | 0 | 0 | 1 | 128 KB | Lower 1/64 + * 0 | 1 | 0 | 1 | 0 | 256 KB | Lower 1/32 + * 0 | 1 | 0 | 1 | 1 | 512 KB | Lower 1/16 + * 0 | 1 | 1 | 0 | 0 | 1 MB | Lower 1/8 + * 0 | 1 | 1 | 0 | 1 | 2 MB | Lower 1/4 + * 0 | 1 | 1 | 1 | 0 | 4 MB | Lower 1/2 * * Returns negative on errors, 0 on success. */ @@ -504,6 +521,8 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len) u8 mask = SR_BP2 | SR_BP1 | SR_BP0; u8 shift = ffs(mask) - 1, pow, val; loff_t lock_len; + bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB; + bool use_top; int ret; status_old = read_sr(nor); @@ -514,13 +533,26 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len) if (stm_is_locked_sr(nor, ofs, len, status_old)) return 0; + /* If anything below us is unlocked, we can't use 'bottom' protection */ + if (!stm_is_locked_sr(nor, 0, ofs, status_old)) + can_be_bottom = false; + /* If anything above us is unlocked, we can't use 'top' protection */ if (!stm_is_locked_sr(nor, ofs + len, mtd->size - (ofs + len), status_old)) + can_be_top = false; + + if (!can_be_bottom && !can_be_top) return -EINVAL; + /* Prefer top, if both are valid */ + use_top = can_be_top; + /* lock_len: length of region that should end up locked */ - lock_len = mtd->size - ofs; + if (use_top) + lock_len = mtd->size - ofs; + else + lock_len = ofs + len; /* * Need smallest pow such that: @@ -539,11 +571,14 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len) if (!(val & mask)) return -EINVAL; - status_new = (status_old & ~mask) | val; + status_new = (status_old & ~mask & ~SR_TB) | val; /* Disallow further writes if WP pin is asserted */ status_new |= SR_SRWD; + if (!use_top) + status_new |= SR_TB; + /* Don't bother if they're the same */ if (status_new == status_old) return 0; @@ -571,6 +606,8 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) u8 mask = SR_BP2 | SR_BP1 | SR_BP0; u8 shift = ffs(mask) - 1, pow, val; loff_t lock_len; + bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB; + bool use_top; int ret; status_old = read_sr(nor); @@ -583,10 +620,24 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) /* If anything below us is locked, we can't use 'top' protection */ if (!stm_is_unlocked_sr(nor, 0, ofs, status_old)) + can_be_top = false; + + /* If anything above us is locked, we can't use 'bottom' protection */ + if (!stm_is_unlocked_sr(nor, ofs + len, mtd->size - (ofs + len), + status_old)) + can_be_bottom = false; + + if (!can_be_bottom && !can_be_top) return -EINVAL; + /* Prefer top, if both are valid */ + use_top = can_be_top; + /* lock_len: length of region that should remain locked */ - lock_len = mtd->size - (ofs + len); + if (use_top) + lock_len = mtd->size - (ofs + len); + else + lock_len = ofs; /* * Need largest pow such that: @@ -607,12 +658,15 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) return -EINVAL; } - status_new = (status_old & ~mask) | val; + status_new = (status_old & ~mask & ~SR_TB) | val; /* Don't protect status register if we're fully unlocked */ if (lock_len == mtd->size) status_new &= ~SR_SRWD; + if (!use_top) + status_new |= SR_TB; + /* Don't bother if they're the same */ if (status_new == status_old) return 0; @@ -1277,6 +1331,8 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) if (info->flags & USE_FSR) nor->flags |= SNOR_F_USE_FSR; + if (info->flags & SPI_NOR_HAS_TB) + nor->flags |= SNOR_F_HAS_SR_TB; #ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS /* prefer "small sector" erase if possible */ |