hwmon: (pmbus/ltc2978): Add support for LTC2977

LTC2977 is a pin compatible replacement for LTC2978.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/pmbus/ltc2978.c

@@ -1,5 +1,6 @@
 /*
- * Hardware monitoring driver for LTC2974, LTC2978, LTC3880, and LTC3883
+ * Hardware monitoring driver for LTC2974, LTC2977, LTC2978, LTC3880,
+ * and LTC3883
  *
  * Copyright (c) 2011 Ericsson AB.
  * Copyright (c) 2013 Guenter Roeck
@@ -27,7 +28,7 @@
 #include <linux/i2c.h>
 #include "pmbus.h"
 
-enum chips { ltc2974, ltc2978, ltc3880, ltc3883 };
+enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3883 };
 
 /* Common for all chips */
 #define LTC2978_MFR_VOUT_PEAK		0xdd
@@ -35,7 +36,7 @@ enum chips { ltc2974, ltc2978, ltc3880, ltc3883 };
 #define LTC2978_MFR_TEMPERATURE_PEAK	0xdf
 #define LTC2978_MFR_SPECIAL_ID		0xe7
 
-/* LTC2974 and LTC2978 */
+/* LTC2974, LCT2977, and LTC2978 */
 #define LTC2978_MFR_VOUT_MIN		0xfb
 #define LTC2978_MFR_VIN_MIN		0xfc
 #define LTC2978_MFR_TEMPERATURE_MIN	0xfd
@@ -53,6 +54,7 @@ enum chips { ltc2974, ltc2978, ltc3880, ltc3883 };
 #define LTC3883_MFR_IIN_PEAK		0xe1
 
 #define LTC2974_ID			0x0212
+#define LTC2977_ID			0x0130
 #define LTC2978_ID_REV1			0x0121
 #define LTC2978_ID_REV2			0x0122
 #define LTC3880_ID			0x4000
@@ -363,6 +365,7 @@ static int ltc2978_write_word_data(struct i2c_client *client, int page,
 
 static const struct i2c_device_id ltc2978_id[] = {
 	{"ltc2974", ltc2974},
+	{"ltc2977", ltc2977},
 	{"ltc2978", ltc2978},
 	{"ltc3880", ltc3880},
 	{"ltc3883", ltc3883},
@@ -392,6 +395,8 @@ static int ltc2978_probe(struct i2c_client *client,
 
 	if (chip_id == LTC2974_ID) {
 		data->id = ltc2974;
+	} else if (chip_id == LTC2977_ID) {
+		data->id = ltc2977;
 	} else if (chip_id == LTC2978_ID_REV1 || chip_id == LTC2978_ID_REV2) {
 		data->id = ltc2978;
 	} else if ((chip_id & LTC3880_ID_MASK) == LTC3880_ID) {
@@ -438,6 +443,7 @@ static int ltc2978_probe(struct i2c_client *client,
 			  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
 		}
 		break;
+	case ltc2977:
 	case ltc2978:
 		info->read_word_data = ltc2978_read_word_data;
 		info->pages = LTC2978_NUM_PAGES;