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-rw-r--r--drivers/regulator/core.c41
-rw-r--r--include/linux/regulator/driver.h6
2 files changed, 41 insertions, 6 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 6d2ce8a..ca8e164 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);
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 31f2055..592cd7c 100644
--- a/include/linux/regulator/driver.h
+++ b/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.
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