regulator: Add of_regulator_bulk_get_all

It work exactly like regulator_bulk_get() but instead of working on a
provided list of names, it seek all consumers properties matching
xxx-supply.

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Link: https://lore.kernel.org/r/20221115073603.3425396-2-clabbe@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/of_regulator.c

@@ -701,3 +701,95 @@ struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
 
 	return c_rdev;
 }
+
+/*
+ * Check if name is a supply name according to the '*-supply' pattern
+ * return 0 if false
+ * return length of supply name without the -supply
+ */
+static int is_supply_name(const char *name)
+{
+	int strs, i;
+
+	strs = strlen(name);
+	/* string need to be at minimum len(x-supply) */
+	if (strs < 8)
+		return 0;
+	for (i = strs - 6; i > 0; i--) {
+		/* find first '-' and check if right part is supply */
+		if (name[i] != '-')
+			continue;
+		if (strcmp(name + i + 1, "supply") != 0)
+			return 0;
+		return i;
+	}
+	return 0;
+}
+
+/*
+ * of_regulator_bulk_get_all - get multiple regulator consumers
+ *
+ * @dev:	Device to supply
+ * @np:		device node to search for consumers
+ * @consumers:  Configuration of consumers; clients are stored here.
+ *
+ * @return number of regulators on success, an errno on failure.
+ *
+ * This helper function allows drivers to get several regulator
+ * consumers in one operation.  If any of the regulators cannot be
+ * acquired then any regulators that were allocated will be freed
+ * before returning to the caller.
+ */
+int of_regulator_bulk_get_all(struct device *dev, struct device_node *np,
+			      struct regulator_bulk_data **consumers)
+{
+	int num_consumers = 0;
+	struct regulator *tmp;
+	struct property *prop;
+	int i, n = 0, ret;
+	char name[64];
+
+	*consumers = NULL;
+
+	/*
+	 * first pass: get numbers of xxx-supply
+	 * second pass: fill consumers
+	 */
+restart:
+	for_each_property_of_node(np, prop) {
+		i = is_supply_name(prop->name);
+		if (i == 0)
+			continue;
+		if (!*consumers) {
+			num_consumers++;
+			continue;
+		} else {
+			memcpy(name, prop->name, i);
+			name[i] = '\0';
+			tmp = regulator_get(dev, name);
+			if (!tmp) {
+				ret = -EINVAL;
+				goto error;
+			}
+			(*consumers)[n].consumer = tmp;
+			n++;
+			continue;
+		}
+	}
+	if (*consumers)
+		return num_consumers;
+	if (num_consumers == 0)
+		return 0;
+	*consumers = kmalloc_array(num_consumers,
+				   sizeof(struct regulator_bulk_data),
+				   GFP_KERNEL);
+	if (!*consumers)
+		return -ENOMEM;
+	goto restart;
+
+error:
+	while (--n >= 0)
+		regulator_put(consumers[n]->consumer);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_regulator_bulk_get_all);

include/linux/regulator/consumer.h

@@ -244,6 +244,8 @@ int regulator_disable_deferred(struct regulator *regulator, int ms);
 
 int __must_check regulator_bulk_get(struct device *dev, int num_consumers,
 				    struct regulator_bulk_data *consumers);
+int __must_check of_regulator_bulk_get_all(struct device *dev, struct device_node *np,
+					   struct regulator_bulk_data **consumers);
 int __must_check devm_regulator_bulk_get(struct device *dev, int num_consumers,
 					 struct regulator_bulk_data *consumers);
 void devm_regulator_bulk_put(struct regulator_bulk_data *consumers);
@@ -479,6 +481,12 @@ static inline int devm_regulator_bulk_get(struct device *dev, int num_consumers,
 	return 0;
 }
 
+static inline int of_regulator_bulk_get_all(struct device *dev, struct device_node *np,
+					    struct regulator_bulk_data **consumers)
+{
+	return 0;
+}
+
 static inline int regulator_bulk_enable(int num_consumers,
 					struct regulator_bulk_data *consumers)
 {