From 5e09e69db23106a0494aa32017f5c82484659fe3 Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie@opensource.wolfsonmicro.com>
Date: Mon, 21 Dec 2009 12:21:52 +0000
Subject: [PATCH] --- yaml --- r: 185657 b: refs/heads/master c:
 31aae2beeb3d601d556b6a8c39085940ad1e9f42 h: refs/heads/master i:   185655:
 4daa343ac8cb36c8f3522a67c729223cebbe0d6d v: v3

---
 [refs]                                 |  2 +-
 trunk/drivers/regulator/core.c         | 41 ++++++++++++++++++++++----
 trunk/include/linux/regulator/driver.h |  6 ++++
 3 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/[refs] b/[refs]
index ec22171db834..aeefb489d8bd 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 84b6826306119dc3c41ef9d7ed6c408112f63301
+refs/heads/master: 31aae2beeb3d601d556b6a8c39085940ad1e9f42
diff --git a/trunk/drivers/regulator/core.c b/trunk/drivers/regulator/core.c
index 6d2ce8a05331..ca8e1642538b 100644
--- a/trunk/drivers/regulator/core.c
+++ b/trunk/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 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
 	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);
diff --git a/trunk/include/linux/regulator/driver.h b/trunk/include/linux/regulator/driver.h
index 31f2055eae28..592cd7c642c2 100644
--- a/trunk/include/linux/regulator/driver.h
+++ b/trunk/include/linux/regulator/driver.h
@@ -58,6 +58,9 @@ enum regulator_status {
  * @get_optimum_mode: Get the most efficient operating mode for the regulator
  *                    when running with the specified parameters.
  *
+ * @enable_time: Time taken for the regulator voltage output voltage to
+ *               stabalise after being enabled, in microseconds.
+ *
  * @set_suspend_voltage: Set the voltage for the regulator when the system
  *                       is suspended.
  * @set_suspend_enable: Mark the regulator as enabled when the system is
@@ -93,6 +96,9 @@ struct regulator_ops {
 	int (*set_mode) (struct regulator_dev *, unsigned int mode);
 	unsigned int (*get_mode) (struct regulator_dev *);
 
+	/* Time taken to enable the regulator */
+	int (*enable_time) (struct regulator_dev *);
+
 	/* report regulator status ... most other accessors report
 	 * control inputs, this reports results of combining inputs
 	 * from Linux (and other sources) with the actual load.