mtd: add an ioctl to query the lock status of a flash sector

This patchs adds a way for user space programs to find out whether a
flash sector is locked. An optional driver method in the mtd_info struct
provides the information.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index 62f3ea9..2fadb02 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -63,6 +63,8 @@
 static void cfi_intelext_sync (struct mtd_info *);
 static int cfi_intelext_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
 static int cfi_intelext_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
+static int cfi_intelext_is_locked(struct mtd_info *mtd, loff_t ofs,
+				  uint64_t len);
 #ifdef CONFIG_MTD_OTP
 static int cfi_intelext_read_fact_prot_reg (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
 static int cfi_intelext_read_user_prot_reg (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
@@ -448,6 +450,7 @@
 	mtd->sync    = cfi_intelext_sync;
 	mtd->lock    = cfi_intelext_lock;
 	mtd->unlock  = cfi_intelext_unlock;
+	mtd->is_locked = cfi_intelext_is_locked;
 	mtd->suspend = cfi_intelext_suspend;
 	mtd->resume  = cfi_intelext_resume;
 	mtd->flags   = MTD_CAP_NORFLASH;
@@ -2139,6 +2142,13 @@
 	return ret;
 }
 
+static int cfi_intelext_is_locked(struct mtd_info *mtd, loff_t ofs,
+				  uint64_t len)
+{
+	return cfi_varsize_frob(mtd, do_getlockstatus_oneblock,
+				ofs, len, NULL) ? 1 : 0;
+}
+
 #ifdef CONFIG_MTD_OTP
 
 typedef int (*otp_op_t)(struct map_info *map, struct flchip *chip,