libmtd: add lock/unlock helpers

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

2 files changed, 56 insertions, 0 deletions

diff --git a/include/libmtd.h b/include/libmtd.h
index afaba42..e30c8a6 100644
--- a/include/libmtd.h
+++ b/include/libmtd.h
@@ -138,6 +138,30 @@ int mtd_get_dev_info(libmtd_t desc, const char *node, struct mtd_dev_info *mtd);
 int mtd_get_dev_info1(libmtd_t desc, int mtd_num, struct mtd_dev_info *mtd);
 
 /**
+ * mtd_lock - lock eraseblocks.
+ * @desc: MTD library descriptor
+ * @mtd: MTD device description object
+ * @fd: MTD device node file descriptor
+ * @eb: eraseblock to lock
+ *
+ * This function locks eraseblock @eb. Returns %0 in case of success and %-1
+ * in case of failure.
+ */
+int mtd_lock(const struct mtd_dev_info *mtd, int fd, int eb);
+
+/**
+ * mtd_unlock - unlock eraseblocks.
+ * @desc: MTD library descriptor
+ * @mtd: MTD device description object
+ * @fd: MTD device node file descriptor
+ * @eb: eraseblock to lock
+ *
+ * This function unlocks eraseblock @eb. Returns %0 in case of success and %-1
+ * in case of failure.
+ */
+int mtd_unlock(const struct mtd_dev_info *mtd, int fd, int eb);
+
+/**
  * mtd_erase - erase an eraseblock.
  * @desc: MTD library descriptor
  * @mtd: MTD device description object
diff --git a/lib/libmtd.c b/lib/libmtd.c
index d57ae8f..1b3d597 100644
--- a/lib/libmtd.c
+++ b/lib/libmtd.c
@@ -802,6 +802,38 @@ static int mtd_valid_erase_block(const struct mtd_dev_info *mtd, int eb)
 	return 0;
 }
 
+static int mtd_xlock(const struct mtd_dev_info *mtd, int fd, int eb, int req,
+		     const char *sreq)
+{
+	int ret;
+	struct erase_info_user ei;
+
+	ret = mtd_valid_erase_block(mtd, eb);
+	if (ret)
+		return ret;
+
+	ei.start = eb * mtd->eb_size;
+	ei.length = mtd->eb_size;
+
+	ret = ioctl(fd, req, &ei);
+	if (ret < 0)
+		return sys_errmsg("%s ioctl failed for eraseblock %d "
+				  "(mtd%d)", sreq, eb, mtd->mtd_num);
+
+	return 0;
+}
+#define mtd_xlock(mtd, fd, eb, req) mtd_xlock(mtd, fd, eb, req, #req)
+
+int mtd_lock(const struct mtd_dev_info *mtd, int fd, int eb)
+{
+	return mtd_xlock(mtd, fd, eb, MEMLOCK);
+}
+
+int mtd_unlock(const struct mtd_dev_info *mtd, int fd, int eb)
+{
+	return mtd_xlock(mtd, fd, eb, MEMUNLOCK);
+}
+
 int mtd_erase(libmtd_t desc, const struct mtd_dev_info *mtd, int fd, int eb)
 {
 	int ret;