Merge branch 'debug-aml' into release

[safe/jmp/linux-2.6] / drivers / regulator / core.c

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 60fcd98..efe568d 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1191,16 +1191,21 @@ void regulator_put(struct regulator *regulator)
 }
 EXPORT_SYMBOL_GPL(regulator_put);
 
+static int _regulator_can_change_status(struct regulator_dev *rdev)
+{
+       if (!rdev->constraints)
+               return 0;
+
+       if (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_STATUS)
+               return 1;
+       else
+               return 0;
+}
+
 /* locks held by regulator_enable() */
 static int _regulator_enable(struct regulator_dev *rdev)
 {
-       int ret = -EINVAL;
-
-       if (!rdev->constraints) {
-               printk(KERN_ERR "%s: %s has no constraints\n",
-                      __func__, rdev->desc->name);
-               return ret;
-       }
+       int ret;
 
        /* do we need to enable the supply regulator first */
        if (rdev->supply) {
@@ -1213,24 +1218,35 @@ static int _regulator_enable(struct regulator_dev *rdev)
        }
 
        /* check voltage and requested load before enabling */
-       if (rdev->desc->ops->enable) {
+       if (rdev->constraints &&
+           (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS))
+               drms_uA_update(rdev);
 
-               if (rdev->constraints &&
-                       (rdev->constraints->valid_ops_mask &
-                       REGULATOR_CHANGE_DRMS))
-                       drms_uA_update(rdev);
-
-               ret = rdev->desc->ops->enable(rdev);
-               if (ret < 0) {
-                       printk(KERN_ERR "%s: failed to enable %s: %d\n",
+       if (rdev->use_count == 0) {
+               /* The regulator may on if it's not switchable or left on */
+               ret = _regulator_is_enabled(rdev);
+               if (ret == -EINVAL || ret == 0) {
+                       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 {
+                               return -EINVAL;
+                       }
+               } else if (ret < 0) {
+                       printk(KERN_ERR "%s: is_enabled() failed for %s: %d\n",
                               __func__, rdev->desc->name, ret);
                        return ret;
                }
-               rdev->use_count++;
-               return ret;
+               /* Fallthrough on positive return values - already enabled */
        }
 
-       return ret;
+       rdev->use_count++;
+
+       return 0;
 }
 
 /**
@@ -1267,10 +1283,12 @@ static int _regulator_disable(struct regulator_dev *rdev)
                return -EIO;
 
        /* are we the last user and permitted to disable ? */
-       if (rdev->use_count == 1 && !rdev->constraints->always_on) {
+       if (rdev->use_count == 1 &&
+           (rdev->constraints && !rdev->constraints->always_on)) {
 
                /* we are last user */
-               if (rdev->desc->ops->disable) {
+               if (_regulator_can_change_status(rdev) &&
+                   rdev->desc->ops->disable) {
                        ret = rdev->desc->ops->disable(rdev);
                        if (ret < 0) {
                                printk(KERN_ERR "%s: failed to disable %s\n",