regulator: enable supply regulator only when use count is zero

[pandora-kernel.git] / drivers / regulator / core.c

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index cc8b337..c577c6d 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -33,6 +33,7 @@ static DEFINE_MUTEX(regulator_list_mutex);
 static LIST_HEAD(regulator_list);
 static LIST_HEAD(regulator_map_list);
 static int has_full_constraints;
+static bool board_wants_dummy_regulator;
 
 /*
  * struct regulator_map
@@ -63,7 +64,8 @@ struct regulator {
 };
 
 static int _regulator_is_enabled(struct regulator_dev *rdev);
-static int _regulator_disable(struct regulator_dev *rdev);
+static int _regulator_disable(struct regulator_dev *rdev,
+               struct regulator_dev **supply_rdev_ptr);
 static int _regulator_get_voltage(struct regulator_dev *rdev);
 static int _regulator_get_current_limit(struct regulator_dev *rdev);
 static unsigned int _regulator_get_mode(struct regulator_dev *rdev);
@@ -1050,7 +1052,6 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
                        printk(KERN_WARNING
                               "%s: could not add device link %s err %d\n",
                               __func__, dev->kobj.name, err);
-                       device_remove_file(dev, &regulator->dev_attr);
                        goto link_name_err;
                }
        }
@@ -1108,6 +1109,11 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
                }
        }
 
+       if (board_wants_dummy_regulator) {
+               rdev = dummy_regulator_rdev;
+               goto found;
+       }
+
 #ifdef CONFIG_REGULATOR_DUMMY
        if (!devname)
                devname = "deviceless";
@@ -1261,13 +1267,17 @@ static int _regulator_enable(struct regulator_dev *rdev)
 {
        int ret, delay;
 
-       /* do we need to enable the supply regulator first */
-       if (rdev->supply) {
-               ret = _regulator_enable(rdev->supply);
-               if (ret < 0) {
-                       printk(KERN_ERR "%s: failed to enable %s: %d\n",
-                              __func__, rdev_get_name(rdev), ret);
-                       return ret;
+       if (rdev->use_count == 0) {
+               /* do we need to enable the supply regulator first */
+               if (rdev->supply) {
+                       mutex_lock(&rdev->supply->mutex);
+                       ret = _regulator_enable(rdev->supply);
+                       mutex_unlock(&rdev->supply->mutex);
+                       if (ret < 0) {
+                               printk(KERN_ERR "%s: failed to enable %s: %d\n",
+                                      __func__, rdev_get_name(rdev), ret);
+                               return ret;
+                       }
                }
        }
 
@@ -1306,10 +1316,12 @@ static int _regulator_enable(struct regulator_dev *rdev)
                        if (ret < 0)
                                return ret;
 
-                       if (delay >= 1000)
+                       if (delay >= 1000) {
                                mdelay(delay / 1000);
-                       else if (delay)
+                               udelay(delay % 1000);
+                       } else if (delay) {
                                udelay(delay);
+                       }
 
                } else if (ret < 0) {
                        printk(KERN_ERR "%s: is_enabled() failed for %s: %d\n",
@@ -1348,9 +1360,11 @@ int regulator_enable(struct regulator *regulator)
 EXPORT_SYMBOL_GPL(regulator_enable);
 
 /* locks held by regulator_disable() */
-static int _regulator_disable(struct regulator_dev *rdev)
+static int _regulator_disable(struct regulator_dev *rdev,
+               struct regulator_dev **supply_rdev_ptr)
 {
        int ret = 0;
+       *supply_rdev_ptr = NULL;
 
        if (WARN(rdev->use_count <= 0,
                        "unbalanced disables for %s\n",
@@ -1376,8 +1390,7 @@ static int _regulator_disable(struct regulator_dev *rdev)
                }
 
                /* decrease our supplies ref count and disable if required */
-               if (rdev->supply)
-                       _regulator_disable(rdev->supply);
+               *supply_rdev_ptr = rdev->supply;
 
                rdev->use_count = 0;
        } else if (rdev->use_count > 1) {
@@ -1407,17 +1420,29 @@ static int _regulator_disable(struct regulator_dev *rdev)
 int regulator_disable(struct regulator *regulator)
 {
        struct regulator_dev *rdev = regulator->rdev;
+       struct regulator_dev *supply_rdev = NULL;
        int ret = 0;
 
        mutex_lock(&rdev->mutex);
-       ret = _regulator_disable(rdev);
+       ret = _regulator_disable(rdev, &supply_rdev);
        mutex_unlock(&rdev->mutex);
+
+       /* decrease our supplies ref count and disable if required */
+       while (supply_rdev != NULL) {
+               rdev = supply_rdev;
+
+               mutex_lock(&rdev->mutex);
+               _regulator_disable(rdev, &supply_rdev);
+               mutex_unlock(&rdev->mutex);
+       }
+
        return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_disable);
 
 /* locks held by regulator_force_disable() */
-static int _regulator_force_disable(struct regulator_dev *rdev)
+static int _regulator_force_disable(struct regulator_dev *rdev,
+               struct regulator_dev **supply_rdev_ptr)
 {
        int ret = 0;
 
@@ -1436,8 +1461,7 @@ static int _regulator_force_disable(struct regulator_dev *rdev)
        }
 
        /* decrease our supplies ref count and disable if required */
-       if (rdev->supply)
-               _regulator_disable(rdev->supply);
+       *supply_rdev_ptr = rdev->supply;
 
        rdev->use_count = 0;
        return ret;
@@ -1454,12 +1478,17 @@ static int _regulator_force_disable(struct regulator_dev *rdev)
  */
 int regulator_force_disable(struct regulator *regulator)
 {
+       struct regulator_dev *supply_rdev = NULL;
        int ret;
 
        mutex_lock(&regulator->rdev->mutex);
        regulator->uA_load = 0;
-       ret = _regulator_force_disable(regulator->rdev);
+       ret = _regulator_force_disable(regulator->rdev, &supply_rdev);
        mutex_unlock(&regulator->rdev->mutex);
+
+       if (supply_rdev)
+               regulator_disable(get_device_regulator(rdev_get_dev(supply_rdev)));
+
        return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_force_disable);
@@ -2323,6 +2352,7 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
        if (init_data->supply_regulator && init_data->supply_regulator_dev) {
                dev_err(dev,
                        "Supply regulator specified by both name and dev\n");
+               ret = -EINVAL;
                goto scrub;
        }
 
@@ -2341,6 +2371,7 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
                if (!found) {
                        dev_err(dev, "Failed to find supply %s\n",
                                init_data->supply_regulator);
+                       ret = -ENODEV;
                        goto scrub;
                }
 
@@ -2462,6 +2493,22 @@ void regulator_has_full_constraints(void)
 }
 EXPORT_SYMBOL_GPL(regulator_has_full_constraints);
 
+/**
+ * regulator_use_dummy_regulator - Provide a dummy regulator when none is found
+ *
+ * Calling this function will cause the regulator API to provide a
+ * dummy regulator to consumers if no physical regulator is found,
+ * allowing most consumers to proceed as though a regulator were
+ * configured.  This allows systems such as those with software
+ * controllable regulators for the CPU core only to be brought up more
+ * readily.
+ */
+void regulator_use_dummy_regulator(void)
+{
+       board_wants_dummy_regulator = true;
+}
+EXPORT_SYMBOL_GPL(regulator_use_dummy_regulator);
+
 /**
  * rdev_get_drvdata - get rdev regulator driver data
  * @rdev: regulator