hwmon: (pmbus/ltc2978) Add support for LTM4676

The chip's programming interface is quite similar to LTC3880
and supports the same set of sensors.

Reviewed-by: Robert Coulson <rob.coulson@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/ltc2978

@@ -23,6 +23,10 @@ Supported chips:
     Prefix: 'ltc3883'
     Addresses scanned: -
     Datasheet: http://www.linear.com/product/ltc3883
+  * Linear Technology LTM4676
+    Prefix: 'ltm4676'
+    Addresses scanned: -
+    Datasheet: http://www.linear.com/product/ltm4676
 
 Author: Guenter Roeck <linux@roeck-us.net>
 
@@ -33,7 +37,8 @@ Description
 LTC2974 is a quad digital power supply manager. LTC2978 is an octal power supply
 monitor. LTC2977 is a pin compatible replacement for LTC2978. LTC3880 is a dual
 output poly-phase step-down DC/DC controller. LTC3883 is a single phase
-step-down DC/DC controller.
+step-down DC/DC controller. LTM4676 is a dual 13A or single 26A uModule
+regulator.
 
 
 Usage Notes
@@ -75,7 +80,7 @@ in[N]_label		"vout[1-8]".
 			LTC2974: N=2-5
 			LTC2977: N=2-9
 			LTC2978: N=2-9
-			LTC3880: N=2-3
+			LTC3880, LTM4676: N=2-3
 			LTC3883: N=2
 in[N]_input		Measured output voltage.
 in[N]_min		Minimum output voltage.
@@ -95,7 +100,7 @@ temp[N]_input		Measured temperature.
 			and temp5 reports the chip temperature.
 			On LTC2977 and LTC2978, only one temperature measurement
 			is supported and reports the chip temperature.
-			On LTC3880, temp1 and temp2 report external
+			On LTC3880 and LTM4676, temp1 and temp2 report external
 			temperatures, and temp3 reports the chip temperature.
 			On LTC3883, temp1 reports an external temperature,
 			and temp2 reports the chip temperature.
@@ -123,11 +128,11 @@ power[N]_label		"pout[1-4]".
 			LTC2974: N=1-4
 			LTC2977: Not supported
 			LTC2978: Not supported
-			LTC3880: N=1-2
+			LTC3880, LTM4676: N=1-2
 			LTC3883: N=2
 power[N]_input		Measured output power.
 
-curr1_label		"iin". LTC3880 and LTC3883 only.
+curr1_label		"iin". LTC3880, LTC3883, and LTM4676 only.
 curr1_input		Measured input current.
 curr1_max		Maximum input current.
 curr1_max_alarm		Input current high alarm.
@@ -138,7 +143,7 @@ curr[N]_label		"iout[1-4]".
 			LTC2974: N=1-4
 			LTC2977: not supported
 			LTC2978: not supported
-			LTC3880: N=2-3
+			LTC3880, LTM4676: N=2-3
 			LTC3883: N=2
 curr[N]_input		Measured output current.
 curr[N]_max		Maximum output current.

drivers/hwmon/pmbus/ltc2978.c

@@ -1,9 +1,9 @@
 /*
  * Hardware monitoring driver for LTC2974, LTC2977, LTC2978, LTC3880,
- * and LTC3883
+ * LTC3883, and LTM4676
  *
  * Copyright (c) 2011 Ericsson AB.
- * Copyright (c) 2013 Guenter Roeck
+ * Copyright (c) 2013, 2014 Guenter Roeck
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -14,10 +14,6 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #include <linux/kernel.h>
@@ -28,7 +24,7 @@
 #include <linux/i2c.h>
 #include "pmbus.h"
 
-enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3883 };
+enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3883, ltm4676 };
 
 /* Common for all chips */
 #define LTC2978_MFR_VOUT_PEAK		0xdd
@@ -45,7 +41,7 @@ enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3883 };
 #define LTC2974_MFR_IOUT_PEAK		0xd7
 #define LTC2974_MFR_IOUT_MIN		0xd8
 
-/* LTC3880 and LTC3883 */
+/* LTC3880, LTC3883, and LTM4676 */
 #define LTC3880_MFR_IOUT_PEAK		0xd7
 #define LTC3880_MFR_CLEAR_PEAKS		0xe3
 #define LTC3880_MFR_TEMPERATURE2_PEAK	0xf4
@@ -63,6 +59,8 @@ enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3883 };
 #define LTC3880_ID_MASK			0xff00
 #define LTC3883_ID			0x4300
 #define LTC3883_ID_MASK			0xff00
+#define LTM4676_ID			0x4480	/* datasheet claims 0x440X */
+#define LTM4676_ID_MASK			0xfff0
 
 #define LTC2974_NUM_PAGES		4
 #define LTC2978_NUM_PAGES		8
@@ -371,6 +369,7 @@ static const struct i2c_device_id ltc2978_id[] = {
 	{"ltc2978", ltc2978},
 	{"ltc3880", ltc3880},
 	{"ltc3883", ltc3883},
+	{"ltm4676", ltm4676},
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, ltc2978_id);
@@ -406,6 +405,8 @@ static int ltc2978_probe(struct i2c_client *client,
 		data->id = ltc3880;
 	} else if ((chip_id & LTC3883_ID_MASK) == LTC3883_ID) {
 		data->id = ltc3883;
+	} else if ((chip_id & LTM4676_ID_MASK) == LTM4676_ID) {
+		data->id = ltm4676;
 	} else {
 		dev_err(&client->dev, "Unsupported chip ID 0x%x\n", chip_id);
 		return -ENODEV;
@@ -459,6 +460,7 @@ static int ltc2978_probe(struct i2c_client *client,
 		}
 		break;
 	case ltc3880:
+	case ltm4676:
 		info->read_word_data = ltc3880_read_word_data;
 		info->pages = LTC3880_NUM_PAGES;
 		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
@@ -501,5 +503,5 @@ static struct i2c_driver ltc2978_driver = {
 module_i2c_driver(ltc2978_driver);
 
 MODULE_AUTHOR("Guenter Roeck");
-MODULE_DESCRIPTION("PMBus driver for LTC2974, LTC2978, LTC3880, and LTC3883");
+MODULE_DESCRIPTION("PMBus driver for LTC2974, LTC2978, LTC3880, LTC3883, and LTM4676");
 MODULE_LICENSE("GPL");