hwmon: (ltc2978) Add support for LTC2975

LTC2975 is mostly compatible to LTC2974, but supports input current
and power measurement.

Tested-by: Michael Jones <mike@proclivis.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

2 files changed, 96 insertions, 12 deletions

diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 43b6de900ce5..8279727987cb 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -52,8 +52,8 @@ config SENSORS_LTC2978
         default n
         help
           If you say yes here you get hardware monitoring support for Linear
-          Technology LTC2974, LTC2977, LTC2978, LTC3880, LTC3883, LTC3887,
-          and LTM4676.
+          Technology LTC2974, LTC2975, LTC2977, LTC2978, LTC3880, LTC3883,
+          LTC3887, and LTM4676.
 
           This driver can also be built as a module. If so, the module will
           be called ltc2978.
diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c
index 0756d8ae9dad..e153ffd59ab0 100644
--- a/drivers/hwmon/pmbus/ltc2978.c
+++ b/drivers/hwmon/pmbus/ltc2978.c
@@ -1,9 +1,8 @@
 /*
- * Hardware monitoring driver for LTC2974, LTC2977, LTC2978, LTC3880,
- * LTC3883, LTC3887. and LTM4676
+ * Hardware monitoring driver for LTC2978 and compatible chips.
  *
  * Copyright (c) 2011 Ericsson AB.
- * Copyright (c) 2013, 2014 Guenter Roeck
+ * Copyright (c) 2013, 2014, 2015 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
@@ -25,8 +24,8 @@
 #include <linux/regulator/driver.h>
 #include "pmbus.h"
 
-enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3882, ltc3883, ltc3887,
-             ltm4676 };
+enum chips { ltc2974, ltc2975, ltc2977, ltc2978, ltc3880, ltc3882, ltc3883,
+             ltc3887, ltm4676 };
 
 /* Common for all chips */
 #define LTC2978_MFR_VOUT_PEAK           0xdd
@@ -34,12 +33,12 @@ enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3882, ltc3883, ltc3887,
 #define LTC2978_MFR_TEMPERATURE_PEAK    0xdf
 #define LTC2978_MFR_SPECIAL_ID          0xe7    /* Not on LTC3882 */
 
-/* LTC2974, LCT2977, and LTC2978 */
+/* LTC2974, LTC2975, LCT2977, and LTC2978 */
 #define LTC2978_MFR_VOUT_MIN            0xfb
 #define LTC2978_MFR_VIN_MIN             0xfc
 #define LTC2978_MFR_TEMPERATURE_MIN     0xfd
 
-/* LTC2974 only */
+/* LTC2974, LTC2975 */
 #define LTC2974_MFR_IOUT_PEAK           0xd7
 #define LTC2974_MFR_IOUT_MIN            0xd8
 
@@ -51,8 +50,15 @@ enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3882, ltc3883, ltc3887,
 /* LTC3883 only */
 #define LTC3883_MFR_IIN_PEAK            0xe1
 
+/* LTC2975 only */
+#define LTC2975_MFR_IIN_PEAK            0xc4
+#define LTC2975_MFR_IIN_MIN             0xc5
+#define LTC2975_MFR_PIN_PEAK            0xc6
+#define LTC2975_MFR_PIN_MIN             0xc7
+
 #define LTC2974_ID_REV1                 0x0212
 #define LTC2974_ID_REV2                 0x0213
+#define LTC2975_ID                      0x0223
 #define LTC2977_ID                      0x0130
 #define LTC2978_ID_REV1                 0x0121
 #define LTC2978_ID_REV2                 0x0122
@@ -87,7 +93,8 @@ struct ltc2978_data {
         u16 temp_min[LTC2974_NUM_PAGES], temp_max[LTC2974_NUM_PAGES];
         u16 vout_min[LTC2978_NUM_PAGES], vout_max[LTC2978_NUM_PAGES];
         u16 iout_min[LTC2974_NUM_PAGES], iout_max[LTC2974_NUM_PAGES];
-        u16 iin_max;
+        u16 iin_min, iin_max;
+        u16 pin_min, pin_max;
         u16 temp2_max;
         struct pmbus_driver_info info;
 };
@@ -246,6 +253,60 @@ static int ltc2974_read_word_data(struct i2c_client *client, int page, int reg)
         return ret;
 }
 
+static int ltc2975_read_word_data(struct i2c_client *client, int page, int reg)
+{
+        const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+        struct ltc2978_data *data = to_ltc2978_data(info);
+        int ret;
+
+        switch (reg) {
+        case PMBUS_VIRT_READ_IIN_MAX:
+                ret = pmbus_read_word_data(client, page, LTC2975_MFR_IIN_PEAK);
+                if (ret >= 0) {
+                        if (lin11_to_val(ret)
+                            > lin11_to_val(data->iin_max))
+                                data->iin_max = ret;
+                        ret = data->iin_max;
+                }
+                break;
+        case PMBUS_VIRT_READ_IIN_MIN:
+                ret = pmbus_read_word_data(client, page, LTC2975_MFR_IIN_MIN);
+                if (ret >= 0) {
+                        if (lin11_to_val(ret)
+                            < lin11_to_val(data->iin_min))
+                                data->iin_min = ret;
+                        ret = data->iin_min;
+                }
+                break;
+        case PMBUS_VIRT_READ_PIN_MAX:
+                ret = pmbus_read_word_data(client, page, LTC2975_MFR_PIN_PEAK);
+                if (ret >= 0) {
+                        if (lin11_to_val(ret)
+                            > lin11_to_val(data->pin_max))
+                                data->pin_max = ret;
+                        ret = data->pin_max;
+                }
+                break;
+        case PMBUS_VIRT_READ_PIN_MIN:
+                ret = pmbus_read_word_data(client, page, LTC2975_MFR_PIN_MIN);
+                if (ret >= 0) {
+                        if (lin11_to_val(ret)
+                            < lin11_to_val(data->pin_min))
+                                data->pin_min = ret;
+                        ret = data->pin_min;
+                }
+                break;
+        case PMBUS_VIRT_RESET_IIN_HISTORY:
+        case PMBUS_VIRT_RESET_PIN_HISTORY:
+                ret = 0;
+                break;
+        default:
+                ret = ltc2978_read_word_data(client, page, reg);
+                break;
+        }
+        return ret;
+}
+
 static int ltc3880_read_word_data(struct i2c_client *client, int page, int reg)
 {
         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
@@ -337,7 +398,13 @@ static int ltc2978_write_word_data(struct i2c_client *client, int page,
         switch (reg) {
         case PMBUS_VIRT_RESET_IIN_HISTORY:
                 data->iin_max = 0x7c00;
-                ret = ltc2978_clear_peaks(client, page, data->id);
+                data->iin_min = 0x7bff;
+                ret = ltc2978_clear_peaks(client, 0, data->id);
+                break;
+        case PMBUS_VIRT_RESET_PIN_HISTORY:
+                data->pin_max = 0x7c00;
+                data->pin_min = 0x7bff;
+                ret = ltc2978_clear_peaks(client, 0, data->id);
                 break;
         case PMBUS_VIRT_RESET_IOUT_HISTORY:
                 data->iout_max[page] = 0x7c00;
@@ -372,6 +439,7 @@ static int ltc2978_write_word_data(struct i2c_client *client, int page,
 
 static const struct i2c_device_id ltc2978_id[] = {
         {"ltc2974", ltc2974},
+        {"ltc2975", ltc2975},
         {"ltc2977", ltc2977},
         {"ltc2978", ltc2978},
         {"ltc3880", ltc3880},
@@ -428,6 +496,8 @@ static int ltc2978_get_id(struct i2c_client *client)
 
         if (chip_id == LTC2974_ID_REV1 || chip_id == LTC2974_ID_REV2)
                 return ltc2974;
+        else if (chip_id == LTC2975_ID)
+                return ltc2975;
         else if (chip_id == LTC2977_ID)
                 return ltc2977;
         else if (chip_id == LTC2978_ID_REV1 || chip_id == LTC2978_ID_REV2 ||
@@ -505,6 +575,19 @@ static int ltc2978_probe(struct i2c_client *client,
                           | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
                 }
                 break;
+        case ltc2975:
+                info->read_word_data = ltc2975_read_word_data;
+                info->pages = LTC2974_NUM_PAGES;
+                info->func[0] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN
+                  | PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
+                  | PMBUS_HAVE_TEMP2;
+                for (i = 0; i < info->pages; i++) {
+                        info->func[i] |= PMBUS_HAVE_VOUT
+                          | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_POUT
+                          | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
+                          | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
+                }
+                break;
         case ltc2977:
         case ltc2978:
                 info->read_word_data = ltc2978_read_word_data;
@@ -576,6 +659,7 @@ static int ltc2978_probe(struct i2c_client *client,
 #ifdef CONFIG_OF
 static const struct of_device_id ltc2978_of_match[] = {
         { .compatible = "lltc,ltc2974" },
+        { .compatible = "lltc,ltc2975" },
         { .compatible = "lltc,ltc2977" },
         { .compatible = "lltc,ltc2978" },
         { .compatible = "lltc,ltc3880" },
@@ -601,5 +685,5 @@ static struct i2c_driver ltc2978_driver = {
 module_i2c_driver(ltc2978_driver);
 
 MODULE_AUTHOR("Guenter Roeck");
-MODULE_DESCRIPTION("PMBus driver for LTC2974, LTC2978, LTC3880, LTC3883, and LTM4676");
+MODULE_DESCRIPTION("PMBus driver for LTC2978 and comppatible chips");
 MODULE_LICENSE("GPL");