@@ -1459,6 +1459,56 @@ static int macronix_quad_enable(struct spi_nor *nor)
return 0;
}
+/**
+ * issi_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 the status register
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int issi_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
+{
+ int status_old, status_new, blk_prot;
+ u8 mask = SR_BP3 | SR_BP2 | SR_BP1 | SR_BP0;
+ u8 shift = ffs(mask) - 1;
+ u8 pow;
+ loff_t num_blks;
+
+ 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,
+ "Status register is Write Protected, can't lock bit
+ protection bits...\n");
+ return -EINVAL;
+ }
+ num_blks = len / nor->info->sector_size;
+
+ pow = order_base_2(num_blks);
+
+ blk_prot = mask & (((pow+1) & 0xf)<<shift);
+
+ /*
+ * Return if older protected blocks include the new requested block's
+ */
+ if (((status_old >> shift) & 0x0f) > blk_prot) {
+ dev_info(nor->dev, "newly requested blocks are
+ already protected ");
+ return 0;
+ }
+
+ status_new = status_old | blk_prot;
+
+ if (status_old == status_new)
+ return 0;
+
+ return write_sr_and_check(nor, status_new, mask);
+}
/**
* issi_unlock() - clear BP[0123] write-protection.
@@ -4124,6 +4174,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
/* NOR protection support for ISSI chips */
if (JEDEC_MFR(info) == SNOR_MFR_ISSI ||
info->flags & SPI_NOR_HAS_LOCK) {
+ nor->flash_lock = issi_lock;
nor->flash_unlock = issi_unlock;
}
Implement a basic locking scheme for ISSI devices similar to that of stm_lock mechanism. The is25xxxxx devices have 4 bits for selecting the range of blocks to be locked/protected from erase/write. The current implementation enables block protection as per the table defined into datasheet for is25wp256d device. Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com> --- drivers/mtd/spi-nor/spi-nor.c | 51 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+)