regulator: Add generic DT parsing for regulators

Looking up init data for regulators found on chips is a common operation
that can be handled in a generic way. The new helper function introduced
by this patch looks up the children of a given node by names specified
in a match table and fills that match table with information parsed from
the DT.

This is based on work by Rhyland Klein <rklein@nvidia.com>.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index 679734d..56593b7 100644 (file)
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c
@@ -14,6 +14,7 @@
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
 
 static void of_get_regulation_constraints(struct device_node *np,
                                        struct regulator_init_data **init_data)
@@ -85,3 +86,49 @@ struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
        return init_data;
 }
 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
+
+/**
+ * of_regulator_match - extract regulator init data
+ * @dev: device requesting the data
+ * @node: parent device node of the regulators
+ * @matches: match table for the regulators
+ * @num_matches: number of entries in match table
+ *
+ * This function uses a match table specified by the regulator driver and
+ * looks up the corresponding init data in the device tree. Note that the
+ * match table is modified in place.
+ *
+ * Returns the number of matches found or a negative error code on failure.
+ */
+int of_regulator_match(struct device *dev, struct device_node *node,
+                      struct of_regulator_match *matches,
+                      unsigned int num_matches)
+{
+       unsigned int count = 0;
+       unsigned int i;
+
+       if (!dev || !node)
+               return -EINVAL;
+
+       for (i = 0; i < num_matches; i++) {
+               struct of_regulator_match *match = &matches[i];
+               struct device_node *child;
+
+               child = of_find_node_by_name(node, match->name);
+               if (!child)
+                       continue;
+
+               match->init_data = of_get_regulator_init_data(dev, child);
+               if (!match->init_data) {
+                       dev_err(dev, "failed to parse DT for regulator %s\n",
+                               child->name);
+                       return -EINVAL;
+               }
+
+               match->of_node = child;
+               count++;
+       }
+
+       return count;
+}
+EXPORT_SYMBOL_GPL(of_regulator_match);

diff --git a/include/linux/regulator/of_regulator.h b/include/linux/regulator/of_regulator.h
index 769704f..f921796 100644 (file)
--- a/include/linux/regulator/of_regulator.h
+++ b/include/linux/regulator/of_regulator.h
@@ -6,10 +6,20 @@
 #ifndef __LINUX_OF_REG_H
 #define __LINUX_OF_REG_H
 
+struct of_regulator_match {
+       const char *name;
+       void *driver_data;
+       struct regulator_init_data *init_data;
+       struct device_node *of_node;
+};
+
 #if defined(CONFIG_OF)
 extern struct regulator_init_data
        *of_get_regulator_init_data(struct device *dev,
                                    struct device_node *node);
+extern int of_regulator_match(struct device *dev, struct device_node *node,
+                             struct of_regulator_match *matches,
+                             unsigned int num_matches);
 #else
 static inline struct regulator_init_data
        *of_get_regulator_init_data(struct device *dev,
@@ -17,6 +27,14 @@ static inline struct regulator_init_data
 {
        return NULL;
 }
+
+static inline int of_regulator_match(struct device *dev,
+                                    struct device_node *node,
+                                    struct of_regulator_match *matches,
+                                    unsigned int num_matches)
+{
+       return 0;
+}
 #endif /* CONFIG_OF */
 
 #endif /* __LINUX_OF_REG_H */