regulator: enable supply regulator only when use count is zero

Supply regulators are disabled only when the last
reference count is removed on the child regulator
(the use count goes from 1 to 0). This patch changes
the behaviour of enable so the supply regulator is
enabled only when the use count of the child
regulator goes from 0 to 1.

Signed-off-by: Bengt Jonsson <bengt.g.jonsson@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 27d062e..c577c6d 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1267,15 +1267,17 @@ static int _regulator_enable(struct regulator_dev *rdev)
 {
        int ret, delay;
 
-       /* do we need to enable the supply regulator first */
-       if (rdev->supply) {
-               mutex_lock(&rdev->supply->mutex);
-               ret = _regulator_enable(rdev->supply);
-               mutex_unlock(&rdev->supply->mutex);
-               if (ret < 0) {
-                       printk(KERN_ERR "%s: failed to enable %s: %d\n",
-                              __func__, rdev_get_name(rdev), ret);
-                       return ret;
+       if (rdev->use_count == 0) {
+               /* do we need to enable the supply regulator first */
+               if (rdev->supply) {
+                       mutex_lock(&rdev->supply->mutex);
+                       ret = _regulator_enable(rdev->supply);
+                       mutex_unlock(&rdev->supply->mutex);
+                       if (ret < 0) {
+                               printk(KERN_ERR "%s: failed to enable %s: %d\n",
+                                      __func__, rdev_get_name(rdev), ret);
+                               return ret;
+                       }
                }
        }