UBI: add mtd_num sysfs attribute

Expose number or the underlying MTD device in sysfs.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 0ed8105f9c11..5098e6d57092 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -122,6 +122,8 @@ static struct device_attribute dev_min_io_size =
         __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
 static struct device_attribute dev_bgt_enabled =
         __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_mtd_num =
+        __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
 
 /**
  * ubi_get_device - get UBI device.
@@ -257,8 +259,10 @@ static ssize_t dev_attribute_show(struct device *dev,
                 ret = sprintf(buf, "%d\n", ubi->min_io_size);
         else if (attr == &dev_bgt_enabled)
                 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
+        else if (attr == &dev_mtd_num)
+                ret = sprintf(buf, "%d\n", ubi->mtd->index);
         else
-                BUG();
+                ret = -EINVAL;
 
         ubi_put_device(ubi);
         return ret;
@@ -314,6 +318,9 @@ static int ubi_sysfs_init(struct ubi_device *ubi)
         if (err)
                 return err;
         err = device_create_file(&ubi->dev, &dev_bgt_enabled);
+        if (err)
+                return err;
+        err = device_create_file(&ubi->dev, &dev_mtd_num);
         return err;
 }
 
@@ -323,6 +330,7 @@ static int ubi_sysfs_init(struct ubi_device *ubi)
  */
 static void ubi_sysfs_close(struct ubi_device *ubi)
 {
+        device_remove_file(&ubi->dev, &dev_mtd_num);
         device_remove_file(&ubi->dev, &dev_bgt_enabled);
         device_remove_file(&ubi->dev, &dev_min_io_size);
         device_remove_file(&ubi->dev, &dev_max_vol_count);