[PATCH v2 1/2] hwmon: (adm1275) Allow setting sample averaging

[Potin Lai <potin.lai@quantatw.com>]

Current driver assume PWR_AVG and VI_AVG as 1 by default, and user needs to
set sample averaging via sysfs manually.

This patch parses the properties below from device tree, and setting
sample averaging during probe.

- adi,power-sample-average
- adi,volt-curr-sample-average

Signed-off-by: Potin Lai <potin.lai@quantatw.com>
---
 drivers/hwmon/pmbus/adm1275.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
index d311e0557401..4fc1421b7540 100644
--- a/drivers/hwmon/pmbus/adm1275.c
+++ b/drivers/hwmon/pmbus/adm1275.c
@@ -83,6 +83,8 @@ enum chips { adm1075, adm1272, adm1275, adm1276, adm1278, adm1293, adm1294 };
 #define ADM1278_VI_AVG_MASK		GENMASK(ADM1278_VI_AVG_SHIFT + 2, \
 						ADM1278_VI_AVG_SHIFT)
 
+#define ADM1275_SAMPLES_AVG_MAX_INDEX	7
+
 struct adm1275_data {
 	int id;
 	bool have_oc_fault;
@@ -475,6 +477,7 @@ static int adm1275_probe(struct i2c_client *client)
 	int vindex = -1, voindex = -1, cindex = -1, pindex = -1;
 	int tindex = -1;
 	u32 shunt;
+	u8 avgindex;
 
 	if (!i2c_check_functionality(client->adapter,
 				     I2C_FUNC_SMBUS_READ_BYTE_DATA
@@ -756,6 +759,34 @@ static int adm1275_probe(struct i2c_client *client)
 		return -ENODEV;
 	}
 
+	if (data->have_power_sampling &&
+	    of_property_read_u8(client->dev.of_node,
+				"adi,power-sample-average", &avgindex) == 0) {
+		if (avgindex > ADM1275_SAMPLES_AVG_MAX_INDEX)
+			return -EINVAL;
+		ret = adm1275_write_pmon_config(data, client, true, avgindex);
+		if (ret < 0) {
+			dev_err(&client->dev,
+				"Setting power sample averaging failed with error %d",
+				ret);
+			return ret;
+		}
+	}
+
+	if (of_property_read_u8(client->dev.of_node,
+				"adi,volt-curr-sample-average",
+				&avgindex) == 0) {
+		if (avgindex > ADM1275_SAMPLES_AVG_MAX_INDEX)
+			return -EINVAL;
+		ret = adm1275_write_pmon_config(data, client, false, avgindex);
+		if (ret < 0) {
+			dev_err(&client->dev,
+				"Setting voltage and current sample averaging failed with error %d",
+				ret);
+			return ret;
+		}
+	}
+
 	if (voindex < 0)
 		voindex = vindex;
 	if (vindex >= 0) {
-- 
2.17.1