From: Venkatesh Yadav Abbarapu venkatesh.abbarapu@amd.com
GIGADEVICE nor flashes provide block protection support using BP0, BP1, BP2, BP3 & TB bits in status register.
BP(Block Protection) bits defines memory to be software protected against PROGRAM or ERASE operations. When one or more block protect bits are set to 1, a designated memory area is protected from PROGRAM and ERASE operations. TB(Top/Bottom) bit determines whether the protected memory area defined by the block protect bits starts from the top or bottom of the memory array.
Used bottom/top protect to test lock/unlock on zc1751+dc1 board.
Signed-off-by: Venkatesh Yadav Abbarapu venkatesh.abbarapu@amd.com Signed-off-by: Tejas Bhumkar tejas.arvind.bhumkar@amd.com --- drivers/mtd/spi/spi-nor-core.c | 309 +++++++++++++++++++++++++++++++++ include/linux/mtd/spi-nor.h | 2 + 2 files changed, 311 insertions(+)
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c index 3bf1e5471b..3e2491cc3e 100644 --- a/drivers/mtd/spi/spi-nor-core.c +++ b/drivers/mtd/spi/spi-nor-core.c @@ -5164,6 +5164,307 @@ static int issi_flash_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) return ret; } #endif /* CONFIG_SPI_FLASH_ISSI */ + +#if defined(CONFIG_SPI_FLASH_GIGADEVICE) +static void giga_get_locked_range(struct spi_nor *nor, u8 sr, loff_t *ofs, + uint64_t *len) +{ + struct mtd_info *mtd = &nor->mtd; + int shift = 0; + int pow; + u8 mask = SR_BP0 | SR_BP1 | SR_BP2 | SR_BP3_GIGA; + u32 sector_size; + + sector_size = nor->sector_size; + if (nor->flags & SNOR_F_HAS_PARALLEL) + sector_size >>= 1; + + shift = ffs(mask) - 1; + + if (!(sr & mask)) { + /* No protection */ + *ofs = 0; + *len = 0; + } else { + pow = ((sr & mask) >> shift) - 1; + *len = sector_size << pow; + if (*len > mtd->size) + *len = mtd->size; + /* GIGA device's have top/bottom select bit in status reg */ + if (nor->flags & SNOR_F_HAS_SR_TB && sr & SR_TB_GIGA) + *ofs = 0; + else + *ofs = mtd->size - *len; + } +} + +/** + * giga_check_lock_status_sr() - check the status register and return + * the region is locked or unlocked + * @nor: pointer to a 'struct spi_nor'. + * @ofs: offset of the flash + * @len: length to be locked + * @sr: status register + * @locked: locked:1 unlocked:0 value + * + * Return: 1 if the entire region is locked (if @locked is true) or unlocked (if + * @locked is false); 0 otherwise. + */ +static int giga_check_lock_status_sr(struct spi_nor *nor, loff_t ofs, u64 len, + u8 sr, bool locked) +{ + loff_t lock_offs; + u64 lock_len; + + if (!len) + return 1; + + giga_get_locked_range(nor, sr, &lock_offs, &lock_len); + if (locked) + /* Requested range is a sub-range of locked range */ + return (ofs + len <= lock_offs + lock_len) && (ofs >= lock_offs); + + /* Requested range does not overlap with locked range */ + return (ofs >= lock_offs + lock_len) || (ofs + len <= lock_offs); +} + +/** + * giga_is_locked_sr() - check if the memory region is locked + * @nor: pointer to a 'struct spi_nor'. + * @ofs: offset of the flash + * @len: length to be locked + * @sr: status register + * + * Check if memory region is locked. + * + * Return: false if region is locked 0 otherwise. + */ +static int giga_is_locked_sr(struct spi_nor *nor, loff_t ofs, uint64_t len, + u8 sr) +{ + return giga_check_lock_status_sr(nor, ofs, len, sr, true); +} + +/** + * giga_is_unlocked_sr() - check if the memory region is unlocked + * @nor: pointer to a 'struct spi_nor'. + * @ofs: offset of the flash + * @len: length to be locked + * @sr: status register + * + * Check if memory region is unlocked. + * + * Return: false if region is locked 0 otherwise. + */ +static int giga_is_unlocked_sr(struct spi_nor *nor, loff_t ofs, uint64_t len, + u8 sr) +{ + return giga_check_lock_status_sr(nor, ofs, len, sr, false); +} + +/** + * giga_is_unlocked() - check if the memory region is unlocked + * @nor: pointer to a 'struct spi_nor'. + * @ofs: offset of the flash + * @len: length to be locked + * + * Check if memory region is unlocked + * + * Return: false if region is locked 0 otherwise. + */ +static int giga_is_unlocked(struct spi_nor *nor, loff_t ofs, uint64_t len) +{ + int sr; + + sr = read_sr(nor); + if (sr < 0) + return sr; + + return giga_check_lock_status_sr(nor, ofs, len, sr, false); +} + +/** + * giga_nor_select_zone() - Select top area or bottom area to lock/unlock + * @nor: pointer to a 'struct spi_nor'. + * @ofs: offset from which to lock memory. + * @len: number of bytes to unlock. + * @sr: status register + * @tb: pointer to top/bottom bool used in caller function + * @op: zone selection is for lock/unlock operation. 1: lock 0:unlock + * + * Select the top area / bottom area pattern to protect memory blocks. + * + * Return: negative on errors, 0 on success. + */ +static int giga_nor_select_zone(struct spi_nor *nor, loff_t ofs, uint64_t len, + u8 sr, bool *tb, bool op) +{ + int retval = 1; + bool can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB, can_be_top = true; + + if (op) { + /* Select for lock zone operation */ + + /* + * If nothing in our range is unlocked, we don't need + * to do anything. + */ + if (giga_is_locked_sr(nor, ofs, len, sr)) + return 0; + + /* + * If anything below us is unlocked, we can't use 'bottom' + * protection. + */ + if (!giga_is_locked_sr(nor, 0, ofs, sr)) + can_be_bottom = false; + + /* + * If anything above us is unlocked, we can't use 'top' + * protection. + */ + if (!giga_is_locked_sr(nor, ofs + len, + nor->mtd.size - (ofs + len), sr)) + can_be_top = false; + } else { + /* Select unlock zone */ + + /* + * If nothing in our range is locked, we don't need to + * do anything. + */ + if (giga_is_unlocked_sr(nor, ofs, len, sr)) + return 0; + + /* + * If anything below us is locked, we can't use 'top' + * protection + */ + if (!giga_is_unlocked_sr(nor, 0, ofs, sr)) + can_be_top = false; + + /* + * If anything above us is locked, we can't use 'bottom' + * protection + */ + if (!giga_is_unlocked_sr(nor, ofs + len, + nor->mtd.size - (ofs + len), sr)) + can_be_bottom = false; + } + + if (!can_be_bottom && !can_be_top) + return -EINVAL; + + /* Prefer top, if both are valid */ + *tb = can_be_top; + return retval; +} + +/** + * giga_flash_lock() - set BP[0123] write-protection. + * @nor: pointer to a 'struct spi_nor'. + * @ofs: offset from which to lock memory. + * @len: number of bytes to unlock. + * + * Lock a region of the flash.Implementation is based on stm_lock + * Supports the block protection bits BP{0,1,2,3} in status register + * + * Return: 0 on success, -errno otherwise. + */ +static int giga_flash_lock(struct spi_nor *nor, loff_t ofs, uint64_t len) +{ + int status_old, status_new, blk_prot; + loff_t lock_len; + u8 pow, ret, shift; + bool use_top = false; + u8 mask = SR_BP0 | SR_BP1 | SR_BP2 | SR_BP3_GIGA; + + shift = ffs(mask) - 1; + + status_old = read_sr(nor); + /* if status reg is Write protected don't update bit protection */ + if (status_old & SR_SRWD) { + dev_err(nor->dev, + "SR is write protected, can't update BP bits...\n"); + return -EINVAL; + } + + log_debug("SPI Protection: %s\n", (status_old & SR_TB_GIGA) ? "bottom" : "top"); + + ret = giga_nor_select_zone(nor, ofs, len, status_old, &use_top, 1); + /* Older protected blocks include the new requested block's */ + if (ret <= 0) + return ret; + + /* lock_len: length of region that should end up locked */ + if (use_top) + lock_len = nor->mtd.size - ofs; + else + lock_len = ofs + len; + + pow = order_base_2(lock_len); + blk_prot = mask & (((pow + 1) & 0xf) << shift); + if (lock_len <= 0) { + dev_err(nor->dev, "invalid Length to protect"); + return -EINVAL; + } + + status_new = status_old | blk_prot; + if (!use_top) + status_new |= SR_TB_GIGA; + else + status_new &= ~SR_TB_GIGA; + + if (status_old == status_new) + return 0; + + return write_sr_and_check(nor, status_new, mask); +} + +/** + * giga_flash_unlock() - clear BP[0123] write-protection. + * @nor: pointer to a 'struct spi_nor'. + * @ofs: offset from which to unlock memory. + * @len: number of bytes to unlock. + * + * Bits [2345] of the Status Register are BP[0123]. + * Clear the corresponding BP status bits. + * + * Return: 0 on success, -errno otherwise. + */ +static int giga_flash_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) +{ + int ret, val; + u8 mask = SR_BP0 | SR_BP1 | SR_BP2 | SR_BP3_GIGA; + + val = read_sr(nor); + if (val < 0) + return val; + + if (!(val & mask)) + return 0; + + write_enable(nor); + + write_sr(nor, val & ~mask); + + ret = spi_nor_wait_till_ready(nor); + if (ret) + return ret; + + ret = write_disable(nor); + if (ret) + return ret; + + ret = read_sr(nor); + if (ret > 0 && !(ret & mask)) { + dev_info(nor->dev, "block protect bits cleared SR: 0x%x\n", + ret); + ret = 0; + } + return ret; +} +#endif /* CONFIG_SPI_FLASH_GIGADEVICE */ #endif /* CONFIG_SPI_FLASH_LOCK */
#ifdef CONFIG_SPI_FLASH_SOFT_RESET @@ -5399,6 +5700,14 @@ int spi_nor_scan(struct spi_nor *nor) } #endif
+#if defined(CONFIG_SPI_FLASH_GIGADEVICE) + if (JEDEC_MFR(info) == SNOR_MFR_GIGADEVICE) { + nor->flash_lock = giga_flash_lock; + nor->flash_unlock = giga_flash_unlock; + nor->flash_is_unlocked = giga_is_unlocked; + } +#endif + #ifdef CONFIG_SPI_FLASH_SST /* * sst26 series block protection implementation differs from other diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h index 9a560d94a2..797f0f275a 100644 --- a/include/linux/mtd/spi-nor.h +++ b/include/linux/mtd/spi-nor.h @@ -172,6 +172,8 @@ #define SR_BP3 BIT(6) /* Block protect 3 */ #define SR_BP3_MX BIT(5) /* Block protect 3 (Macronix) */ #define SR_BP3_ISSI BIT(5) /* Block protect 3 (ISSI) */ +#define SR_TB_GIGA BIT(6) /* Top/Bottom protect (GIGADEVICE)*/ +#define SR_BP3_GIGA BIT(5) /* Block protect 3 (GIGADEVICE) */ #define SR_TB BIT(5) /* Top/Bottom protect */ #define SR_SRWD BIT(7) /* SR write protect */