[PATCH 4/5] hwmon: pmbus: mpq8785: Implement voltage scale loop configuration

[Pawel Dembicki <paweldembicki@gmail.com>]

Implement support for setting the VOUT_SCALE_LOOP PMBus register
based on an optional device tree property "voltage-scale-loop".

This allows the driver to provide the correct VOUT value depending
on the feedback voltage divider configuration for chips where the
bootloader does not configure the voltage scale.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
---
 drivers/hwmon/pmbus/mpq8785.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/hwmon/pmbus/mpq8785.c b/drivers/hwmon/pmbus/mpq8785.c
index e6a643856f08..6e2325d7f37b 100644
--- a/drivers/hwmon/pmbus/mpq8785.c
+++ b/drivers/hwmon/pmbus/mpq8785.c
@@ -78,6 +78,8 @@ static int mpq8785_probe(struct i2c_client *client)
 	struct device *dev = &client->dev;
 	struct pmbus_driver_info *info;
 	enum chips chip_id;
+	u32 voltage_scale;
+	int ret;
 
 	info = devm_kmemdup(dev, &mpq8785_info, sizeof(*info), GFP_KERNEL);
 	if (!info)
@@ -105,6 +107,14 @@ static int mpq8785_probe(struct i2c_client *client)
 		return -ENODEV;
 	}
 
+	if (!of_property_read_u32(dev->of_node, "voltage-scale-loop",
+				  &voltage_scale)) {
+		ret = i2c_smbus_write_word_data(client, PMBUS_VOUT_SCALE_LOOP,
+						voltage_scale);
+		if (ret)
+			return ret;
+	}
+
 	return pmbus_do_probe(client, info);
 };
 
-- 
2.43.0