diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt
index 2bd8f0978765..e2c7f1e7251a 100644
--- a/Documentation/devicetree/bindings/regulator/regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/regulator.txt
@@ -14,6 +14,11 @@ Optional properties:
 - regulator-ramp-delay: ramp delay for regulator(in uV/uS)
   For hardwares which support disabling ramp rate, it should be explicitly
   intialised to zero (regulator-ramp-delay = <0>) for disabling ramp delay.
+- regulator-enable-ramp-delay: The time taken, in microseconds, for the supply
+  rail to reach the target voltage, plus/minus whatever tolerance the board
+  design requires. This property describes the total system ramp time
+  required due to the combination of internal ramping of the regulator itself,
+  and board design issues such as trace capacitance and load on the supply.
 
 Deprecated properties:
 - regulator-compatible: If a regulator chip contains multiple
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 16427de56ce8..916cadf45279 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -919,6 +919,36 @@ static int machine_constraints_voltage(struct regulator_dev *rdev,
 	return 0;
 }
 
+static int machine_constraints_current(struct regulator_dev *rdev,
+	struct regulation_constraints *constraints)
+{
+	struct regulator_ops *ops = rdev->desc->ops;
+	int ret;
+
+	if (!constraints->min_uA && !constraints->max_uA)
+		return 0;
+
+	if (constraints->min_uA > constraints->max_uA) {
+		rdev_err(rdev, "Invalid current constraints\n");
+		return -EINVAL;
+	}
+
+	if (!ops->set_current_limit || !ops->get_current_limit) {
+		rdev_warn(rdev, "Operation of current configuration missing\n");
+		return 0;
+	}
+
+	/* Set regulator current in constraints range */
+	ret = ops->set_current_limit(rdev, constraints->min_uA,
+			constraints->max_uA);
+	if (ret < 0) {
+		rdev_err(rdev, "Failed to set current constraint, %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 /**
  * set_machine_constraints - sets regulator constraints
  * @rdev: regulator source
@@ -949,6 +979,10 @@ static int set_machine_constraints(struct regulator_dev *rdev,
 	if (ret != 0)
 		goto out;
 
+	ret = machine_constraints_current(rdev, rdev->constraints);
+	if (ret != 0)
+		goto out;
+
 	/* do we need to setup our suspend state */
 	if (rdev->constraints->initial_state) {
 		ret = suspend_prepare(rdev, rdev->constraints->initial_state);
@@ -1182,6 +1216,8 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
 
 static int _regulator_get_enable_time(struct regulator_dev *rdev)
 {
+	if (rdev->constraints && rdev->constraints->enable_time)
+		return rdev->constraints->enable_time;
 	if (!rdev->desc->ops->enable_time)
 		return rdev->desc->enable_time;
 	return rdev->desc->ops->enable_time(rdev);
@@ -1276,7 +1312,7 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
 
 	if (id == NULL) {
 		pr_err("get() with no identifier\n");
-		return regulator;
+		return ERR_PTR(-EINVAL);
 	}
 
 	if (dev)
@@ -1733,11 +1769,39 @@ static int _regulator_do_enable(struct regulator_dev *rdev)
 	 * together.  */
 	trace_regulator_enable_delay(rdev_get_name(rdev));
 
-	if (delay >= 1000) {
-		mdelay(delay / 1000);
-		udelay(delay % 1000);
-	} else if (delay) {
-		udelay(delay);
+	/*
+	 * Delay for the requested amount of time as per the guidelines in:
+	 *
+	 *     Documentation/timers/timers-howto.txt
+	 *
+	 * The assumption here is that regulators will never be enabled in
+	 * atomic context and therefore sleeping functions can be used.
+	 */
+	if (delay) {
+		unsigned int ms = delay / 1000;
+		unsigned int us = delay % 1000;
+
+		if (ms > 0) {
+			/*
+			 * For small enough values, handle super-millisecond
+			 * delays in the usleep_range() call below.
+			 */
+			if (ms < 20)
+				us += ms * 1000;
+			else
+				msleep(ms);
+		}
+
+		/*
+		 * Give the scheduler some room to coalesce with any other
+		 * wakeup sources. For delays shorter than 10 us, don't even
+		 * bother setting up high-resolution timers and just busy-
+		 * loop.
+		 */
+		if (us >= 10)
+			usleep_range(us, us + 100);
+		else
+			udelay(us);
 	}
 
 	trace_regulator_enable_complete(rdev_get_name(rdev));
diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index 7827384680d6..ea4f36f2cbe2 100644
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c
@@ -23,6 +23,8 @@ static void of_get_regulation_constraints(struct device_node *np,
 	const __be32 *min_uA, *max_uA, *ramp_delay;
 	struct property *prop;
 	struct regulation_constraints *constraints = &(*init_data)->constraints;
+	int ret;
+	u32 pval;
 
 	constraints->name = of_get_property(np, "regulator-name", NULL);
 
@@ -73,6 +75,10 @@ static void of_get_regulation_constraints(struct device_node *np,
 		else
 			constraints->ramp_disable = true;
 	}
+
+	ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
+	if (!ret)
+		constraints->enable_time = pval;
 }
 
 /**
diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h
index 999b20ce06cf..8108751acb86 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h
@@ -95,6 +95,7 @@ struct regulator_state {
  * @initial_state: Suspend state to set by default.
  * @initial_mode: Mode to set at startup.
  * @ramp_delay: Time to settle down after voltage change (unit: uV/us)
+ * @enable_time: Turn-on time of the rails (unit: microseconds)
  */
 struct regulation_constraints {
 
@@ -129,6 +130,7 @@ struct regulation_constraints {
 	unsigned int initial_mode;
 
 	unsigned int ramp_delay;
+	unsigned int enable_time;
 
 	/* constraint flags */
 	unsigned always_on:1;	/* regulator never off when system is on */