regulator: Add debugfs file showing the supply map table

Useful for working out why things aren't getting plugged together properly.

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

1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index d8e6a429e8ba..9a33fe2021b6 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2907,6 +2907,43 @@ void *regulator_get_init_drvdata(struct regulator_init_data *reg_init_data)
 }
 EXPORT_SYMBOL_GPL(regulator_get_init_drvdata);
 
+#ifdef CONFIG_DEBUG_FS
+static ssize_t supply_map_read_file(struct file *file, char __user *user_buf,
+                                    size_t count, loff_t *ppos)
+{
+        char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+        ssize_t len, ret = 0;
+        struct regulator_map *map;
+
+        if (!buf)
+                return -ENOMEM;
+
+        list_for_each_entry(map, &regulator_map_list, list) {
+                len = snprintf(buf + ret, PAGE_SIZE - ret,
+                               "%s -> %s.%s\n",
+                               rdev_get_name(map->regulator), map->dev_name,
+                               map->supply);
+                if (len >= 0)
+                        ret += len;
+                if (ret > PAGE_SIZE) {
+                        ret = PAGE_SIZE;
+                        break;
+                }
+        }
+
+        ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
+
+        kfree(buf);
+
+        return ret;
+}
+
+static const struct file_operations supply_map_fops = {
+        .read = supply_map_read_file,
+        .llseek = default_llseek,
+};
+#endif
+
 static int __init regulator_init(void)
 {
         int ret;
@@ -2919,6 +2956,10 @@ static int __init regulator_init(void)
                 pr_warn("regulator: Failed to create debugfs directory\n");
                 debugfs_root = NULL;
         }
+
+        if (IS_ERR(debugfs_create_file("supply_map", 0444, debugfs_root,
+                                       NULL, &supply_map_fops)))
+                pr_warn("regulator: Failed to create supplies debugfs\n");
 #endif
 
         regulator_dummy_init();