3 files changed, 47 insertions, 6 deletions

diff --git a/drivers/regulator/mc13892-regulator.c b/drivers/regulator/mc13892-regulator.c
index 5dd8aaa5cfb8..9891aec47b57 100644
--- a/drivers/regulator/mc13892-regulator.c
+++ b/drivers/regulator/mc13892-regulator.c
@@ -535,15 +535,18 @@ static int mc13892_regulator_probe(struct platform_device *pdev)
         struct mc13xxx_regulator_init_data *mc13xxx_data;
         struct regulator_config config = { };
         int i, ret;
-        int num_regulators = 0;
+        int num_regulators = 0, num_parsed;
         u32 val;
 
         num_regulators = mc13xxx_get_num_regulators_dt(pdev);
+
         if (num_regulators <= 0 && pdata)
                 num_regulators = pdata->num_regulators;
         if (num_regulators <= 0)
                 return -EINVAL;
 
+        num_parsed = num_regulators;
+
         priv = devm_kzalloc(&pdev->dev, sizeof(*priv) +
                 num_regulators * sizeof(priv->regulators[0]),
                 GFP_KERNEL);
@@ -586,7 +589,39 @@ static int mc13892_regulator_probe(struct platform_device *pdev)
                 = mc13892_vcam_get_mode;
 
         mc13xxx_data = mc13xxx_parse_regulators_dt(pdev, mc13892_regulators,
-                                        ARRAY_SIZE(mc13892_regulators));
+                                        ARRAY_SIZE(mc13892_regulators),
+                                        &num_parsed);
+
+        /*
+         * Perform a little sanity check on the regulator tree - if we found
+         * a number of regulators from mc13xxx_get_num_regulators_dt and
+         * then parsed a smaller number in mc13xxx_parse_regulators_dt then
+         * there is a regulator defined in the regulators node which has
+         * not matched any usable regulator in the driver. In this case,
+         * there is one missing and what will happen is the first regulator
+         * will get registered again.
+         *
+         * Fix this by basically making our number of registerable regulators
+         * equal to the number of regulators we parsed. We are allocating
+         * too much memory for priv, but this is unavoidable at this point.
+         *
+         * As an example of how this can happen, try making a typo in your
+         * regulators node (vviohi {} instead of viohi {}) so that the name
+         * does not match..
+         *
+         * The check will basically pass for platform data (non-DT) because
+         * mc13xxx_parse_regulators_dt for !CONFIG_OF will not touch num_parsed.
+         *
+         */
+        if (num_parsed != num_regulators) {
+                dev_warn(&pdev->dev,
+                "parsed %d != regulators %d - check your device tree!\n",
+                        num_parsed, num_regulators);
+
+                num_regulators = num_parsed;
+                priv->num_regulators = num_regulators;
+        }
+
         for (i = 0; i < num_regulators; i++) {
                 struct regulator_init_data *init_data;
                 struct regulator_desc *desc;
diff --git a/drivers/regulator/mc13xxx-regulator-core.c b/drivers/regulator/mc13xxx-regulator-core.c
index 4ed89c654110..2ecf1d8b6a94 100644
--- a/drivers/regulator/mc13xxx-regulator-core.c
+++ b/drivers/regulator/mc13xxx-regulator-core.c
@@ -181,12 +181,14 @@ EXPORT_SYMBOL_GPL(mc13xxx_get_num_regulators_dt);
 
 struct mc13xxx_regulator_init_data *mc13xxx_parse_regulators_dt(
         struct platform_device *pdev, struct mc13xxx_regulator *regulators,
-        int num_regulators)
+        int num_regulators, int *num_parsed)
 {
         struct mc13xxx_regulator_priv *priv = platform_get_drvdata(pdev);
         struct mc13xxx_regulator_init_data *data, *p;
         struct device_node *parent, *child;
-        int i;
+        int i, parsed = 0;
+
+        *num_parsed = 0;
 
         of_node_get(pdev->dev.parent->of_node);
         parent = of_find_node_by_name(pdev->dev.parent->of_node, "regulators");
@@ -203,16 +205,20 @@ struct mc13xxx_regulator_init_data *mc13xxx_parse_regulators_dt(
                 for (i = 0; i < num_regulators; i++) {
                         if (!of_node_cmp(child->name,
                                          regulators[i].desc.name)) {
+
                                 p->id = i;
                                 p->init_data = of_get_regulator_init_data(
                                                         &pdev->dev, child);
                                 p->node = child;
                                 p++;
+
+                                parsed++;
                                 break;
                         }
                 }
         }
 
+        *num_parsed = parsed;
         return data;
 }
 EXPORT_SYMBOL_GPL(mc13xxx_parse_regulators_dt);
diff --git a/drivers/regulator/mc13xxx.h b/drivers/regulator/mc13xxx.h
index 06c8903f182a..007f83387fd6 100644
--- a/drivers/regulator/mc13xxx.h
+++ b/drivers/regulator/mc13xxx.h
@@ -39,7 +39,7 @@ extern int mc13xxx_fixed_regulator_set_voltage(struct regulator_dev *rdev,
 extern int mc13xxx_get_num_regulators_dt(struct platform_device *pdev);
 extern struct mc13xxx_regulator_init_data *mc13xxx_parse_regulators_dt(
         struct platform_device *pdev, struct mc13xxx_regulator *regulators,
-        int num_regulators);
+        int num_regulators, int *num_parsed);
 #else
 static inline int mc13xxx_get_num_regulators_dt(struct platform_device *pdev)
 {
@@ -48,7 +48,7 @@ static inline int mc13xxx_get_num_regulators_dt(struct platform_device *pdev)
 
 static inline struct mc13xxx_regulator_init_data *mc13xxx_parse_regulators_dt(
         struct platform_device *pdev, struct mc13xxx_regulator *regulators,
-        int num_regulators)
+        int num_regulators, int *num_parsed)
 {
         return NULL;
 }