hwmon: (pmbus) Add support for VR12

Newer chips such as MAX20751 support VR12. Add support for it.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

drivers/hwmon/pmbus/pmbus.c

@@ -129,6 +129,7 @@ static int pmbus_identify(struct i2c_client *client,
 				break;
 			case 1:
 				info->format[PSC_VOLTAGE_OUT] = vid;
+				info->vrm_version = vr11;
 				break;
 			case 2:
 				info->format[PSC_VOLTAGE_OUT] = direct;

drivers/hwmon/pmbus/pmbus.h

@@ -338,10 +338,12 @@ enum pmbus_sensor_classes {
 #define PMBUS_HAVE_STATUS_VMON	(1 << 19)
 
 enum pmbus_data_format { linear = 0, direct, vid };
+enum vrm_version { vr11 = 0, vr12 };
 
 struct pmbus_driver_info {
 	int pages;		/* Total number of pages */
 	enum pmbus_data_format format[PSC_NUM_CLASSES];
+	enum vrm_version vrm_version;
 	/*
 	 * Support one set of coefficients for each sensor type
 	 * Used for chips providing data in direct mode.

drivers/hwmon/pmbus/pmbus_core.c

@@ -515,16 +515,24 @@ static long pmbus_reg2data_direct(struct pmbus_data *data,
 /*
  * Convert VID sensor values to milli- or micro-units
  * depending on sensor type.
- * We currently only support VR11.
  */
 static long pmbus_reg2data_vid(struct pmbus_data *data,
 			       struct pmbus_sensor *sensor)
 {
 	long val = sensor->data;
+	long rv = 0;
 
-	if (val < 0x02 || val > 0xb2)
-		return 0;
-	return DIV_ROUND_CLOSEST(160000 - (val - 2) * 625, 100);
+	switch (data->info->vrm_version) {
+	case vr11:
+		if (val >= 0x02 && val <= 0xb2)
+			rv = DIV_ROUND_CLOSEST(160000 - (val - 2) * 625, 100);
+		break;
+	case vr12:
+		if (val >= 0x01)
+			rv = 250 + (val - 1) * 5;
+		break;
+	}
+	return rv;
 }
 
 static long pmbus_reg2data(struct pmbus_data *data, struct pmbus_sensor *sensor)