regulator: Add regulator_bulk_set_voltage

Add a convenience API to set the voltage on multiple consumers
stored in a struct regulator_bulk_data[] in one API call.

Change-Id: Iaeb5ba8c357a66f1401fb1e142bb03904e8e9c7c
Signed-off-by: Justin Paupore <jpaupore@codeaurora.org>

drivers/regulator/core.c

@@ -3533,6 +3533,42 @@ err:
 }
 EXPORT_SYMBOL_GPL(regulator_bulk_enable);
 
+/**
+ * regulator_bulk_set_voltage - set voltage for multiple regulator consumers
+ *
+ * @num_consumers: Number of consumers
+ * @consumers:     Consumer data; clients are stored here.
+ * @return         0 on success, an errno on failure
+ *
+ * This convenience API allows the voted voltage ranges of multiple regulator
+ * clients to be set in a single API call. If any consumers cannot have their
+ * voltages set, this function returns WITHOUT withdrawing votes for any
+ * consumers that have already been set.
+ */
+int regulator_bulk_set_voltage(int num_consumers,
+			       struct regulator_bulk_data *consumers)
+{
+	int i;
+	int rc;
+
+	for (i = 0; i < num_consumers; i++) {
+		if (!consumers[i].min_uV && !consumers[i].max_uV)
+			continue;
+		rc = regulator_set_voltage(consumers[i].consumer,
+				consumers[i].min_uV,
+				consumers[i].max_uV);
+		if (rc)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	pr_err("Failed to set voltage for %s: %d\n", consumers[i].supply, rc);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(regulator_bulk_set_voltage);
+
 /**
  * regulator_bulk_disable - disable multiple regulator consumers
  *

include/linux/regulator/consumer.h

@@ -144,6 +144,10 @@ struct regulator;
  *            using the bulk regulator APIs.
  * @consumer: The regulator consumer for the supply.  This will be managed
  *            by the bulk API.
+ * @min_uV:   The minimum requested voltage for the regulator (in microvolts),
+ *            or 0 to not set a voltage.
+ * @max_uV:   The maximum requested voltage for the regulator (in microvolts),
+ *            or 0 to use @min_uV.
  *
  * The regulator APIs provide a series of regulator_bulk_() API calls as
  * a convenience to consumers which require multiple supplies.  This
@@ -152,6 +156,8 @@ struct regulator;
 struct regulator_bulk_data {
 	const char *supply;
 	struct regulator *consumer;
+	int min_uV;
+	int max_uV;
 
 	/* private: Internal use */
 	int ret;
@@ -216,6 +222,8 @@ int __must_check devm_regulator_bulk_get(struct device *dev, int num_consumers,
 					 struct regulator_bulk_data *consumers);
 int __must_check regulator_bulk_enable(int num_consumers,
 				       struct regulator_bulk_data *consumers);
+int regulator_bulk_set_voltage(int num_consumers,
+			  struct regulator_bulk_data *consumers);
 int regulator_bulk_disable(int num_consumers,
 			   struct regulator_bulk_data *consumers);
 int regulator_bulk_force_disable(int num_consumers,