1 files changed, 203 insertions, 41 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index d4803460a557..6ed568b96c0e 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -147,6 +147,56 @@ static inline struct regulator_dev *rdev_get_supply(struct regulator_dev *rdev)
 }
 
 /**
+ * regulator_lock_nested - lock a single regulator
+ * @rdev:		regulator source
+ * @subclass:		mutex subclass used for lockdep
+ *
+ * This function can be called many times by one task on
+ * a single regulator and its mutex will be locked only
+ * once. If a task, which is calling this function is other
+ * than the one, which initially locked the mutex, it will
+ * wait on mutex.
+ */
+static void regulator_lock_nested(struct regulator_dev *rdev,
+				  unsigned int subclass)
+{
+	if (!mutex_trylock(&rdev->mutex)) {
+		if (rdev->mutex_owner == current) {
+			rdev->ref_cnt++;
+			return;
+		}
+		mutex_lock_nested(&rdev->mutex, subclass);
+	}
+
+	rdev->ref_cnt = 1;
+	rdev->mutex_owner = current;
+}
+
+static inline void regulator_lock(struct regulator_dev *rdev)
+{
+	regulator_lock_nested(rdev, 0);
+}
+
+/**
+ * regulator_unlock - unlock a single regulator
+ * @rdev:		regulator_source
+ *
+ * This function unlocks the mutex when the
+ * reference counter reaches 0.
+ */
+static void regulator_unlock(struct regulator_dev *rdev)
+{
+	if (rdev->ref_cnt != 0) {
+		rdev->ref_cnt--;
+
+		if (!rdev->ref_cnt) {
+			rdev->mutex_owner = NULL;
+			mutex_unlock(&rdev->mutex);
+		}
+	}
+}
+
+/**
  * regulator_lock_supply - lock a regulator and its supplies
  * @rdev:         regulator source
  */
@@ -155,7 +205,7 @@ static void regulator_lock_supply(struct regulator_dev *rdev)
 	int i;
 
 	for (i = 0; rdev; rdev = rdev_get_supply(rdev), i++)
-		mutex_lock_nested(&rdev->mutex, i);
+		regulator_lock_nested(rdev, i);
 }
 
 /**
@@ -167,7 +217,7 @@ static void regulator_unlock_supply(struct regulator_dev *rdev)
 	struct regulator *supply;
 
 	while (1) {
-		mutex_unlock(&rdev->mutex);
+		regulator_unlock(rdev);
 		supply = rdev->supply;
 
 		if (!rdev->supply)
@@ -350,9 +400,9 @@ static ssize_t regulator_uV_show(struct device *dev,
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
 	ssize_t ret;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 	ret = sprintf(buf, "%d\n", _regulator_get_voltage(rdev));
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 
 	return ret;
 }
@@ -416,9 +466,9 @@ static ssize_t regulator_state_show(struct device *dev,
 	struct regulator_dev *rdev = dev_get_drvdata(dev);
 	ssize_t ret;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 	ret = regulator_print_state(buf, _regulator_is_enabled(rdev));
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 
 	return ret;
 }
@@ -526,10 +576,10 @@ static ssize_t regulator_total_uA_show(struct device *dev,
 	struct regulator *regulator;
 	int uA = 0;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 	list_for_each_entry(regulator, &rdev->consumer_list, list)
 		uA += regulator->uA_load;
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 	return sprintf(buf, "%d\n", uA);
 }
 static DEVICE_ATTR(requested_microamps, 0444, regulator_total_uA_show, NULL);
@@ -886,6 +936,18 @@ static int machine_constraints_voltage(struct regulator_dev *rdev,
 	    rdev->constraints->min_uV && rdev->constraints->max_uV) {
 		int target_min, target_max;
 		int current_uV = _regulator_get_voltage(rdev);
+
+		if (current_uV == -ENOTRECOVERABLE) {
+			/* This regulator can't be read and must be initted */
+			rdev_info(rdev, "Setting %d-%duV\n",
+				  rdev->constraints->min_uV,
+				  rdev->constraints->max_uV);
+			_regulator_do_set_voltage(rdev,
+						  rdev->constraints->min_uV,
+						  rdev->constraints->max_uV);
+			current_uV = _regulator_get_voltage(rdev);
+		}
+
 		if (current_uV < 0) {
 			rdev_err(rdev,
 				 "failed to get the current voltage(%d)\n",
@@ -1321,7 +1383,7 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
 	if (regulator == NULL)
 		return NULL;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 	regulator->rdev = rdev;
 	list_add(&regulator->list, &rdev->consumer_list);
 
@@ -1376,12 +1438,12 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
 	    _regulator_is_enabled(rdev))
 		regulator->always_on = true;
 
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 	return regulator;
 overflow_err:
 	list_del(&regulator->list);
 	kfree(regulator);
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 	return NULL;
 }
 
@@ -1770,13 +1832,13 @@ static void _regulator_put(struct regulator *regulator)
 	/* remove any sysfs entries */
 	if (regulator->dev)
 		sysfs_remove_link(&rdev->dev.kobj, regulator->supply_name);
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 	list_del(&regulator->list);
 
 	rdev->open_count--;
 	rdev->exclusive = 0;
 	put_device(&rdev->dev);
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 
 	kfree_const(regulator->supply_name);
 	kfree(regulator);
@@ -2384,7 +2446,7 @@ static void regulator_disable_work(struct work_struct *work)
 						  disable_work.work);
 	int count, i, ret;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 
 	BUG_ON(!rdev->deferred_disables);
 
@@ -2405,7 +2467,7 @@ static void regulator_disable_work(struct work_struct *work)
 			rdev_err(rdev, "Deferred disable failed: %d\n", ret);
 	}
 
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 
 	if (rdev->supply) {
 		for (i = 0; i < count; i++) {
@@ -2440,11 +2502,11 @@ int regulator_disable_deferred(struct regulator *regulator, int ms)
 	if (!ms)
 		return regulator_disable(regulator);
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 	rdev->deferred_disables++;
 	mod_delayed_work(system_power_efficient_wq, &rdev->disable_work,
 			 msecs_to_jiffies(ms));
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 
 	return 0;
 }
@@ -2476,10 +2538,10 @@ static int _regulator_list_voltage(struct regulator_dev *rdev,
 		if (selector >= rdev->desc->n_voltages)
 			return -EINVAL;
 		if (lock)
-			mutex_lock(&rdev->mutex);
+			regulator_lock(rdev);
 		ret = ops->list_voltage(rdev, selector);
 		if (lock)
-			mutex_unlock(&rdev->mutex);
+			regulator_unlock(rdev);
 	} else if (rdev->is_switch && rdev->supply) {
 		ret = _regulator_list_voltage(rdev->supply->rdev,
 					      selector, lock);
@@ -3252,7 +3314,7 @@ int regulator_sync_voltage(struct regulator *regulator)
 	struct regulator_voltage *voltage = &regulator->voltage[PM_SUSPEND_ON];
 	int ret, min_uV, max_uV;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 
 	if (!rdev->desc->ops->set_voltage &&
 	    !rdev->desc->ops->set_voltage_sel) {
@@ -3281,7 +3343,7 @@ int regulator_sync_voltage(struct regulator *regulator)
 	ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
 
 out:
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_sync_voltage);
@@ -3374,7 +3436,7 @@ int regulator_set_current_limit(struct regulator *regulator,
 	struct regulator_dev *rdev = regulator->rdev;
 	int ret;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 
 	/* sanity check */
 	if (!rdev->desc->ops->set_current_limit) {
@@ -3389,7 +3451,7 @@ int regulator_set_current_limit(struct regulator *regulator,
 
 	ret = rdev->desc->ops->set_current_limit(rdev, min_uA, max_uA);
 out:
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_set_current_limit);
@@ -3398,7 +3460,7 @@ static int _regulator_get_current_limit(struct regulator_dev *rdev)
 {
 	int ret;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 
 	/* sanity check */
 	if (!rdev->desc->ops->get_current_limit) {
@@ -3408,7 +3470,7 @@ static int _regulator_get_current_limit(struct regulator_dev *rdev)
 
 	ret = rdev->desc->ops->get_current_limit(rdev);
 out:
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 	return ret;
 }
 
@@ -3444,7 +3506,7 @@ int regulator_set_mode(struct regulator *regulator, unsigned int mode)
 	int ret;
 	int regulator_curr_mode;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 
 	/* sanity check */
 	if (!rdev->desc->ops->set_mode) {
@@ -3468,7 +3530,7 @@ int regulator_set_mode(struct regulator *regulator, unsigned int mode)
 
 	ret = rdev->desc->ops->set_mode(rdev, mode);
 out:
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_set_mode);
@@ -3477,7 +3539,7 @@ static unsigned int _regulator_get_mode(struct regulator_dev *rdev)
 {
 	int ret;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 
 	/* sanity check */
 	if (!rdev->desc->ops->get_mode) {
@@ -3487,7 +3549,7 @@ static unsigned int _regulator_get_mode(struct regulator_dev *rdev)
 
 	ret = rdev->desc->ops->get_mode(rdev);
 out:
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 	return ret;
 }
 
@@ -3508,7 +3570,7 @@ static int _regulator_get_error_flags(struct regulator_dev *rdev,
 {
 	int ret;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 
 	/* sanity check */
 	if (!rdev->desc->ops->get_error_flags) {
@@ -3518,7 +3580,7 @@ static int _regulator_get_error_flags(struct regulator_dev *rdev,
 
 	ret = rdev->desc->ops->get_error_flags(rdev, flags);
 out:
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 	return ret;
 }
 
@@ -3567,10 +3629,10 @@ int regulator_set_load(struct regulator *regulator, int uA_load)
 	struct regulator_dev *rdev = regulator->rdev;
 	int ret;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 	regulator->uA_load = uA_load;
 	ret = drms_uA_update(rdev);
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 
 	return ret;
 }
@@ -3598,7 +3660,7 @@ int regulator_allow_bypass(struct regulator *regulator, bool enable)
 	if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_BYPASS))
 		return 0;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 
 	if (enable && !regulator->bypass) {
 		rdev->bypass_count++;
@@ -3622,7 +3684,7 @@ int regulator_allow_bypass(struct regulator *regulator, bool enable)
 	if (ret == 0)
 		regulator->bypass = enable;
 
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 
 	return ret;
 }
@@ -4067,6 +4129,96 @@ static int regulator_register_resolve_supply(struct device *dev, void *data)
 	return 0;
 }
 
+static int regulator_fill_coupling_array(struct regulator_dev *rdev)
+{
+	struct coupling_desc *c_desc = &rdev->coupling_desc;
+	int n_coupled = c_desc->n_coupled;
+	struct regulator_dev *c_rdev;
+	int i;
+
+	for (i = 1; i < n_coupled; i++) {
+		/* already resolved */
+		if (c_desc->coupled_rdevs[i])
+			continue;
+
+		c_rdev = of_parse_coupled_regulator(rdev, i - 1);
+
+		if (c_rdev) {
+			c_desc->coupled_rdevs[i] = c_rdev;
+			c_desc->n_resolved++;
+		}
+	}
+
+	if (rdev->coupling_desc.n_resolved < n_coupled)
+		return -1;
+	else
+		return 0;
+}
+
+static int regulator_register_fill_coupling_array(struct device *dev,
+						  void *data)
+{
+	struct regulator_dev *rdev = dev_to_rdev(dev);
+
+	if (!IS_ENABLED(CONFIG_OF))
+		return 0;
+
+	if (regulator_fill_coupling_array(rdev))
+		rdev_dbg(rdev, "unable to resolve coupling\n");
+
+	return 0;
+}
+
+static int regulator_resolve_coupling(struct regulator_dev *rdev)
+{
+	int n_phandles;
+
+	if (!IS_ENABLED(CONFIG_OF))
+		n_phandles = 0;
+	else
+		n_phandles = of_get_n_coupled(rdev);
+
+	if (n_phandles + 1 > MAX_COUPLED) {
+		rdev_err(rdev, "too many regulators coupled\n");
+		return -EPERM;
+	}
+
+	/*
+	 * Every regulator should always have coupling descriptor filled with
+	 * at least pointer to itself.
+	 */
+	rdev->coupling_desc.coupled_rdevs[0] = rdev;
+	rdev->coupling_desc.n_coupled = n_phandles + 1;
+	rdev->coupling_desc.n_resolved++;
+
+	/* regulator isn't coupled */
+	if (n_phandles == 0)
+		return 0;
+
+	/* regulator, which can't change its voltage, can't be coupled */
+	if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE)) {
+		rdev_err(rdev, "voltage operation not allowed\n");
+		return -EPERM;
+	}
+
+	if (rdev->constraints->max_spread <= 0) {
+		rdev_err(rdev, "wrong max_spread value\n");
+		return -EPERM;
+	}
+
+	if (!of_check_coupling_data(rdev))
+		return -EPERM;
+
+	/*
+	 * After everything has been checked, try to fill rdevs array
+	 * with pointers to regulators parsed from device tree. If some
+	 * regulators are not registered yet, retry in late init call
+	 */
+	regulator_fill_coupling_array(rdev);
+
+	return 0;
+}
+
 /**
  * regulator_register - register regulator
  * @regulator_desc: regulator to register
@@ -4200,6 +4352,13 @@ regulator_register(const struct regulator_desc *regulator_desc,
 	if (ret < 0)
 		goto wash;
 
+	mutex_lock(&regulator_list_mutex);
+	ret = regulator_resolve_coupling(rdev);
+	mutex_unlock(&regulator_list_mutex);
+
+	if (ret != 0)
+		goto wash;
+
 	/* add consumers devices */
 	if (init_data) {
 		mutex_lock(&regulator_list_mutex);
@@ -4288,9 +4447,9 @@ static int _regulator_suspend_late(struct device *dev, void *data)
 	suspend_state_t *state = data;
 	int ret;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 	ret = suspend_set_state(rdev, *state);
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 
 	return ret;
 }
@@ -4320,14 +4479,14 @@ static int _regulator_resume_early(struct device *dev, void *data)
 	if (rstate == NULL)
 		return 0;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 
 	if (rdev->desc->ops->resume_early &&
 	    (rstate->enabled == ENABLE_IN_SUSPEND ||
 	     rstate->enabled == DISABLE_IN_SUSPEND))
 		ret = rdev->desc->ops->resume_early(rdev);
 
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 
 	return ret;
 }
@@ -4629,7 +4788,7 @@ static int __init regulator_late_cleanup(struct device *dev, void *data)
 	if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS))
 		return 0;
 
-	mutex_lock(&rdev->mutex);
+	regulator_lock(rdev);
 
 	if (rdev->use_count)
 		goto unlock;
@@ -4660,7 +4819,7 @@ static int __init regulator_late_cleanup(struct device *dev, void *data)
 	}
 
 unlock:
-	mutex_unlock(&rdev->mutex);
+	regulator_unlock(rdev);
 
 	return 0;
 }
@@ -4694,6 +4853,9 @@ static int __init regulator_init_complete(void)
 	class_for_each_device(&regulator_class, NULL, NULL,
 			      regulator_late_cleanup);
 
+	class_for_each_device(&regulator_class, NULL, NULL,
+			      regulator_register_fill_coupling_array);
+
 	return 0;
 }
 late_initcall_sync(regulator_init_complete);