mtd: part: Add sysfs variable for offset of partition
This patch makes a sysfs variable called 'offset' on each partition
which contains the offset in bytes from the beginning of the master
device that the partition starts.
Signed-off-by: Dan Ehrenberg <dehrenberg@chromium.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index a19ec5a..be80340 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -554,6 +554,30 @@
return slave;
}
+static ssize_t mtd_partition_offset_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct mtd_info *mtd = dev_get_drvdata(dev);
+ struct mtd_part *part = PART(mtd);
+ return snprintf(buf, PAGE_SIZE, "%lld\n", part->offset);
+}
+
+static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
+
+static const struct attribute *mtd_partition_attrs[] = {
+ &dev_attr_offset.attr,
+ NULL
+};
+
+static int mtd_add_partition_attrs(struct mtd_part *new)
+{
+ int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs);
+ if (ret)
+ printk(KERN_WARNING
+ "mtd: failed to create partition attrs, err=%d\n", ret);
+ return ret;
+}
+
int mtd_add_partition(struct mtd_info *master, const char *name,
long long offset, long long length)
{
@@ -603,6 +627,8 @@
add_mtd_device(&new->mtd);
+ mtd_add_partition_attrs(new);
+
return ret;
err_inv:
mutex_unlock(&mtd_partitions_mutex);
@@ -620,6 +646,8 @@
list_for_each_entry_safe(slave, next, &mtd_partitions, list)
if ((slave->master == master) &&
(slave->mtd.index == partno)) {
+ sysfs_remove_files(&slave->mtd.dev.kobj,
+ mtd_partition_attrs);
ret = del_mtd_device(&slave->mtd);
if (ret < 0)
break;
@@ -663,6 +691,7 @@
mutex_unlock(&mtd_partitions_mutex);
add_mtd_device(&slave->mtd);
+ mtd_add_partition_attrs(slave);
cur_offset = slave->offset + slave->mtd.size;
}