hwmon: (adt7475) set start bit in probe

The ADT7475 and ADT7476 have the STRT bit cleared by default[1]. Before any
monitoring activities the STRT bit needs to be set. Logically this needs
to happen before any of the sensors are read so the probe() function
seems the best place for it.

[1] - https://www.onsemi.com/pub/Collateral/ADT7475-D.PDF

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/adt7475.c

@@ -59,6 +59,8 @@
 #define REG_VENDID		0x3E
 #define REG_DEVID2		0x3F
 
+#define REG_CONFIG1		0x40
+
 #define REG_STATUS1		0x41
 #define REG_STATUS2		0x42
 
@@ -1371,6 +1373,17 @@ static int adt7475_probe(struct i2c_client *client,
 	for (i = 0; i < ADT7475_PWM_COUNT; i++)
 		adt7475_read_pwm(client, i);
 
+	/* Start monitoring */
+	switch (chip) {
+	case adt7475:
+	case adt7476:
+		i2c_smbus_write_byte_data(client, REG_CONFIG1,
+					  adt7475_read(REG_CONFIG1) | 0x01);
+		break;
+	default:
+		break;
+	}
+
 	ret = sysfs_create_group(&client->dev.kobj, &adt7475_attr_group);
 	if (ret)
 		return ret;