commit bf89386f166b18c21b2b7a2c5b6e496726c4f25f
author Guenter Roeck <linux@roeck-us.net> Mon Jun 08 10:29:45 2015 -0700
committer Guenter Roeck <linux@roeck-us.net> Wed Aug 12 12:29:22 2015 -0700
tree 2b85e7be65eb6815ecf03ca24bd3723f17368863
parent 836954dadcb351d65cf96584f22c9e437169bd49

hwmon: (ltc2978) Add support for LTC3882

LTC3882 is mostly compatible with LTC3880. Major differences are that it
does not measure the input current, and it no longer supports LTC's legacy
mechanism to identify the chip.

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

drivers/hwmon/pmbus/ltc2978.c

diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c
index 7e10fbf..28e1e73 100644
--- a/drivers/hwmon/pmbus/ltc2978.c
+++ b/drivers/hwmon/pmbus/ltc2978.c
@@ -25,13 +25,13 @@
 #include <linux/regulator/driver.h>
 #include "pmbus.h"
 
-enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3883, ltm4676 };
+enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3882, ltc3883, ltm4676 };
 
 /* Common for all chips */
 #define LTC2978_MFR_VOUT_PEAK		0xdd
 #define LTC2978_MFR_VIN_PEAK		0xde
 #define LTC2978_MFR_TEMPERATURE_PEAK	0xdf
-#define LTC2978_MFR_SPECIAL_ID		0xe7
+#define LTC2978_MFR_SPECIAL_ID		0xe7	/* Not on LTC3882 */
 
 /* LTC2974, LCT2977, and LTC2978 */
 #define LTC2978_MFR_VOUT_MIN		0xfb
@@ -42,7 +42,7 @@
 #define LTC2974_MFR_IOUT_PEAK		0xd7
 #define LTC2974_MFR_IOUT_MIN		0xd8
 
-/* LTC3880, LTC3883, and LTM4676 */
+/* LTC3880, LTC3882, LTC3883, and LTM4676 */
 #define LTC3880_MFR_IOUT_PEAK		0xd7
 #define LTC3880_MFR_CLEAR_PEAKS		0xe3
 #define LTC3880_MFR_TEMPERATURE2_PEAK	0xf4
@@ -313,7 +313,7 @@
 {
 	int ret;
 
-	if (id == ltc3880 || id == ltc3883 || id == ltm4676)
+	if (id == ltc3880 || id == ltc3882 || id == ltc3883 || id == ltm4676)
 		ret = pmbus_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
 	else
 		ret = pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
@@ -369,6 +369,7 @@
 	{"ltc2977", ltc2977},
 	{"ltc2978", ltc2978},
 	{"ltc3880", ltc3880},
+	{"ltc3882", ltc3882},
 	{"ltc3883", ltc3883},
 	{"ltm4676", ltm4676},
 	{}
@@ -393,8 +394,30 @@
 	int chip_id;
 
 	chip_id = i2c_smbus_read_word_data(client, LTC2978_MFR_SPECIAL_ID);
-	if (chip_id < 0)
-		return chip_id;
+	if (chip_id < 0) {
+		const struct i2c_device_id *id;
+		u8 buf[I2C_SMBUS_BLOCK_MAX];
+		int ret;
+
+		if (!i2c_check_functionality(client->adapter,
+					     I2C_FUNC_SMBUS_READ_BLOCK_DATA))
+			return -ENODEV;
+
+		ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
+		if (ret < 0)
+			return ret;
+		if (ret < 3 || strncmp(buf, "LTC", 3))
+			return -ENODEV;
+
+		ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
+		if (ret < 0)
+			return ret;
+		for (id = &ltc2978_id[0]; strlen(id->name); id++) {
+			if (!strncasecmp(id->name, buf, strlen(id->name)))
+				return (int)id->driver_data;
+		}
+		return -ENODEV;
+	}
 
 	if (chip_id == LTC2974_ID_REV1 || chip_id == LTC2974_ID_REV2)
 		return ltc2974;
@@ -498,6 +521,20 @@
 		  | PMBUS_HAVE_POUT
 		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 		break;
+	case ltc3882:
+		info->read_word_data = ltc3880_read_word_data;
+		info->pages = LTC3880_NUM_PAGES;
+		info->func[0] = PMBUS_HAVE_VIN
+		  | PMBUS_HAVE_STATUS_INPUT
+		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+		  | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
+		  | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
+		info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+		  | PMBUS_HAVE_POUT
+		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
+		break;
 	case ltc3883:
 		info->read_word_data = ltc3883_read_word_data;
 		info->pages = LTC3883_NUM_PAGES;
@@ -530,6 +567,7 @@
 	{ .compatible = "lltc,ltc2977" },
 	{ .compatible = "lltc,ltc2978" },
 	{ .compatible = "lltc,ltc3880" },
+	{ .compatible = "lltc,ltc3882" },
 	{ .compatible = "lltc,ltc3883" },
 	{ .compatible = "lltc,ltm4676" },
 	{ }