int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf);
int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf);
int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,