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>

1 files changed, 11 insertions, 9 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 27d062e1395c..c577c6d344ac 100644
--- 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;
+                        }
                 }
         }