iio: gyro: bmg160: Add rudimentary regulator support

BMG160 needs VDD and VDDIO regulators that might need to be explicitly
enabled. Add some rudimentary support to obtain and enable these
regulators during probe() and disable them using a devm action.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201211183815.51269-2-stephan@gerhold.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/gyro/bmg160_core.c

@@ -19,6 +19,7 @@
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 #include "bmg160.h"
 
 #define BMG160_IRQ_NAME		"bmg160_event"
@@ -92,6 +93,7 @@
 
 struct bmg160_data {
 	struct regmap *regmap;
+	struct regulator_bulk_data regulators[2];
 	struct iio_trigger *dready_trig;
 	struct iio_trigger *motion_trig;
 	struct iio_mount_matrix orientation;
@@ -1061,6 +1063,13 @@ static const char *bmg160_match_acpi_device(struct device *dev)
 	return dev_name(dev);
 }
 
+static void bmg160_disable_regulators(void *d)
+{
+	struct bmg160_data *data = d;
+
+	regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
+}
+
 int bmg160_core_probe(struct device *dev, struct regmap *regmap, int irq,
 		      const char *name)
 {
@@ -1077,6 +1086,22 @@ int bmg160_core_probe(struct device *dev, struct regmap *regmap, int irq,
 	data->irq = irq;
 	data->regmap = regmap;
 
+	data->regulators[0].supply = "vdd";
+	data->regulators[1].supply = "vddio";
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(data->regulators),
+				      data->regulators);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to get regulators\n");
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
+				    data->regulators);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, bmg160_disable_regulators, data);
+	if (ret)
+		return ret;
+
 	ret = iio_read_mount_matrix(dev, "mount-matrix",
 				&data->orientation);
 	if (ret)