1 files changed, 35 insertions, 6 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 6d2ce8a05331..ca8e1642538b 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -19,6 +19,7 @@
 #include <linux/err.h>
 #include <linux/mutex.h>
 #include <linux/suspend.h>
+#include <linux/delay.h>
 #include <linux/regulator/consumer.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
@@ -1084,6 +1085,13 @@ overflow_err:
 	return NULL;
 }
 
+static int _regulator_get_enable_time(struct regulator_dev *rdev)
+{
+	if (!rdev->desc->ops->enable_time)
+		return 0;
+	return rdev->desc->ops->enable_time(rdev);
+}
+
 /* Internal regulator request function */
 static struct regulator *_regulator_get(struct device *dev, const char *id,
 					int exclusive)
@@ -1251,7 +1259,7 @@ static int _regulator_can_change_status(struct regulator_dev *rdev)
 /* locks held by regulator_enable() */
 static int _regulator_enable(struct regulator_dev *rdev)
 {
-	int ret;
+	int ret, delay;
 
 	/* do we need to enable the supply regulator first */
 	if (rdev->supply) {
@@ -1275,13 +1283,34 @@ static int _regulator_enable(struct regulator_dev *rdev)
 			if (!_regulator_can_change_status(rdev))
 				return -EPERM;
 
-			if (rdev->desc->ops->enable) {
-				ret = rdev->desc->ops->enable(rdev);
-				if (ret < 0)
-					return ret;
-			} else {
+			if (!rdev->desc->ops->enable)
 				return -EINVAL;
+
+			/* Query before enabling in case configuration
+			 * dependant.  */
+			ret = _regulator_get_enable_time(rdev);
+			if (ret >= 0) {
+				delay = ret;
+			} else {
+				printk(KERN_WARNING
+					"%s: enable_time() failed for %s: %d\n",
+					__func__, rdev_get_name(rdev),
+					ret);
+				delay = 0;
 			}
+
+			/* Allow the regulator to ramp; it would be useful
+			 * to extend this for bulk operations so that the
+			 * regulators can ramp together.  */
+			ret = rdev->desc->ops->enable(rdev);
+			if (ret < 0)
+				return ret;
+
+			if (delay >= 1000)
+				mdelay(delay / 1000);
+			else if (delay)
+				udelay(delay);
+
 		} else if (ret < 0) {
 			printk(KERN_ERR "%s: is_enabled() failed for %s: %d\n",
 			       __func__, rdev_get_name(rdev), ret);