1 files changed, 17 insertions, 2 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 04408896705e..9a6757decd3d 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -670,6 +670,7 @@ static int set_machine_constraints(struct regulator_dev *rdev,
 {
         int ret = 0;
         const char *name;
+        struct regulator_ops *ops = rdev->desc->ops;
 
         if (constraints->name)
                 name = constraints->name;
@@ -683,8 +684,8 @@ static int set_machine_constraints(struct regulator_dev *rdev,
         /* do we need to apply the constraint voltage */
         if (rdev->constraints->apply_uV &&
                 rdev->constraints->min_uV == rdev->constraints->max_uV &&
-                rdev->desc->ops->set_voltage) {
-                ret = rdev->desc->ops->set_voltage(rdev,
+                ops->set_voltage) {
+                ret = ops->set_voltage(rdev,
                         rdev->constraints->min_uV, rdev->constraints->max_uV);
                         if (ret < 0) {
                                 printk(KERN_ERR "%s: failed to apply %duV constraint to %s\n",
@@ -710,6 +711,20 @@ static int set_machine_constraints(struct regulator_dev *rdev,
                 }
         }
 
+        /* if always_on is set then turn the regulator on if it's not
+         * already on. */
+        if (constraints->always_on && ops->enable &&
+            ((ops->is_enabled && !ops->is_enabled(rdev)) ||
+             (!ops->is_enabled && !constraints->boot_on))) {
+                ret = ops->enable(rdev);
+                if (ret < 0) {
+                        printk(KERN_ERR "%s: failed to enable %s\n",
+                               __func__, name);
+                        rdev->constraints = NULL;
+                        goto out;
+                }
+        }
+
         print_constraints(rdev);
 out:
         return ret;