[PATCH 3/4] iio: light: ltr501: Add rudimentary regulator support

[Nikita Travkin <nikita@trvn.ru>]

On some platforms the supply regulators must be enabled before the
sensor can work. Add vdd and vddio regulators for the sensor and IO bus
power respectively.

Signed-off-by: Nikita Travkin <nikita@trvn.ru>
---
 drivers/iio/light/ltr501.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c
index 1830221da48d..57851c8ef1c6 100644
--- a/drivers/iio/light/ltr501.c
+++ b/drivers/iio/light/ltr501.c
@@ -15,6 +15,7 @@
 #include <linux/delay.h>
 #include <linux/regmap.h>
 #include <linux/acpi.h>
+#include <linux/regulator/consumer.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/events.h>
@@ -151,6 +152,7 @@ struct ltr501_chip_info {
 
 struct ltr501_data {
 	struct i2c_client *client;
+	struct regulator_bulk_data regulators[2];
 	struct mutex lock_als, lock_ps;
 	const struct ltr501_chip_info *chip_info;
 	u8 als_contr, ps_contr;
@@ -1379,6 +1381,13 @@ static const struct regmap_config ltr501_regmap_config = {
 	.volatile_reg = ltr501_is_volatile_reg,
 };
 
+static void ltr501_disable_regulators(void *d)
+{
+	struct ltr501_data *data = d;
+
+	regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
+}
+
 static int ltr501_powerdown(struct ltr501_data *data)
 {
 	return ltr501_write_contr(data, data->als_contr &
@@ -1423,6 +1432,25 @@ static int ltr501_probe(struct i2c_client *client,
 	mutex_init(&data->lock_als);
 	mutex_init(&data->lock_ps);
 
+	data->regulators[0].supply = "vdd";
+	data->regulators[1].supply = "vddio";
+	ret = devm_regulator_bulk_get(&client->dev,
+				      ARRAY_SIZE(data->regulators),
+				      data->regulators);
+	if (ret)
+		return dev_err_probe(&client->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(&client->dev,
+				       ltr501_disable_regulators, data);
+	if (ret)
+		return ret;
+
 	data->reg_it = devm_regmap_field_alloc(&client->dev, regmap,
 					       reg_field_it);
 	if (IS_ERR(data->reg_it)) {
-- 
2.30.2