regulator: Add initial per-regulator debugfs support

We only expose the use and open counts to userspace, providing a tiny
bit of insight into what the API is up to.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

2 files changed, 41 insertions, 2 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 6066a8f2d5bb..9fa20957847d 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -17,6 +17,7 @@
 
 #include <linux/kernel.h>
 #include <linux/init.h>
+#include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/slab.h>
 #include <linux/err.h>
@@ -47,6 +48,10 @@ static LIST_HEAD(regulator_map_list);
 static bool has_full_constraints;
 static bool board_wants_dummy_regulator;
 
+#ifdef CONFIG_DEBUG_FS
+static struct dentry *debugfs_root;
+#endif
+
 /*
  * struct regulator_map
  *
@@ -2404,6 +2409,23 @@ static int add_regulator_attributes(struct regulator_dev *rdev)
         return status;
 }
 
+static void rdev_init_debugfs(struct regulator_dev *rdev)
+{
+#ifdef CONFIG_DEBUG_FS
+        rdev->debugfs = debugfs_create_dir(rdev_get_name(rdev), debugfs_root);
+        if (IS_ERR(rdev->debugfs) || !rdev->debugfs) {
+                rdev_warn(rdev, "Failed to create debugfs directory\n");
+                rdev->debugfs = NULL;
+                return;
+        }
+
+        debugfs_create_u32("use_count", 0444, rdev->debugfs,
+                           &rdev->use_count);
+        debugfs_create_u32("open_count", 0444, rdev->debugfs,
+                           &rdev->open_count);
+#endif
+}
+
 /**
  * regulator_register - register regulator
  * @regulator_desc: regulator to register
@@ -2548,6 +2570,8 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
         }
 
         list_add(&rdev->list, &regulator_list);
+
+        rdev_init_debugfs(rdev);
 out:
         mutex_unlock(&regulator_list_mutex);
         return rdev;
@@ -2580,6 +2604,9 @@ void regulator_unregister(struct regulator_dev *rdev)
                 return;
 
         mutex_lock(&regulator_list_mutex);
+#ifdef CONFIG_DEBUG_FS
+        debugfs_remove_recursive(rdev->debugfs);
+#endif
         WARN_ON(rdev->open_count);
         unset_regulator_supplies(rdev);
         list_del(&rdev->list);
@@ -2723,6 +2750,14 @@ static int __init regulator_init(void)
 
         ret = class_register(&regulator_class);
 
+#ifdef CONFIG_DEBUG_FS
+        debugfs_root = debugfs_create_dir("regulator", NULL);
+        if (IS_ERR(debugfs_root) || !debugfs_root) {
+                pr_warn("regulator: Failed to create debugfs directory\n");
+                debugfs_root = NULL;
+        }
+#endif
+
         regulator_dummy_init();
 
         return ret;
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 975ae06cb634..b8ed16a33c47 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -175,9 +175,9 @@ struct regulator_desc {
  */
 struct regulator_dev {
         struct regulator_desc *desc;
-        int use_count;
-        int open_count;
         int exclusive;
+        u32 use_count;
+        u32 open_count;
 
         /* lists we belong to */
         struct list_head list; /* list of all regulators */
@@ -195,6 +195,10 @@ struct regulator_dev {
         struct regulator_dev *supply;   /* for tree */
 
         void *reg_data;         /* regulator_dev data */
+
+#ifdef CONFIG_DEBUG_FS
+        struct dentry *debugfs;
+#endif
 };
 
 struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,