1 files changed, 52 insertions, 2 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index f15b04548715..771c6235cced 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2769,6 +2769,8 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator,
         int ret = 0;
         int old_min_uV, old_max_uV;
         int current_uV;
+        int best_supply_uV = 0;
+        int supply_change_uV = 0;
 
         /* If we're setting the same range as last time the change
          * should be a noop (some cpufreq implementations use the same
@@ -2812,10 +2814,58 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator,
         if (ret < 0)
                 goto out2;
 
+        if (rdev->supply && (rdev->desc->min_dropout_uV ||
+                                !rdev->desc->ops->get_voltage)) {
+                int current_supply_uV;
+                int selector;
+
+                selector = regulator_map_voltage(rdev, min_uV, max_uV);
+                if (selector < 0) {
+                        ret = selector;
+                        goto out2;
+                }
+
+                best_supply_uV = _regulator_list_voltage(regulator, selector, 0);
+                if (best_supply_uV < 0) {
+                        ret = best_supply_uV;
+                        goto out2;
+                }
+
+                best_supply_uV += rdev->desc->min_dropout_uV;
+
+                current_supply_uV = _regulator_get_voltage(rdev->supply->rdev);
+                if (current_supply_uV < 0) {
+                        ret = current_supply_uV;
+                        goto out2;
+                }
+
+                supply_change_uV = best_supply_uV - current_supply_uV;
+        }
+
+        if (supply_change_uV > 0) {
+                ret = regulator_set_voltage_unlocked(rdev->supply,
+                                best_supply_uV, INT_MAX);
+                if (ret) {
+                        dev_err(&rdev->dev, "Failed to increase supply voltage: %d\n",
+                                        ret);
+                        goto out2;
+                }
+        }
+
         ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
         if (ret < 0)
                 goto out2;
 
+        if (supply_change_uV < 0) {
+                ret = regulator_set_voltage_unlocked(rdev->supply,
+                                best_supply_uV, INT_MAX);
+                if (ret)
+                        dev_warn(&rdev->dev, "Failed to decrease supply voltage: %d\n",
+                                        ret);
+                /* No need to fail here */
+                ret = 0;
+        }
+
 out:
         return ret;
 out2:
@@ -2847,11 +2897,11 @@ int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
 {
         int ret = 0;
 
-        mutex_lock(&regulator->rdev->mutex);
+        regulator_lock_supply(regulator->rdev);
 
         ret = regulator_set_voltage_unlocked(regulator, min_uV, max_uV);
 
-        mutex_unlock(&regulator->rdev->mutex);
+        regulator_unlock_supply(regulator->rdev);
 
         return ret;
 }