179ffe859SGuenter Roeck /* 279ffe859SGuenter Roeck * Driver for Linear Technology LTC4222 Dual Hot Swap controller 379ffe859SGuenter Roeck * 479ffe859SGuenter Roeck * Copyright (c) 2014 Guenter Roeck 579ffe859SGuenter Roeck * 679ffe859SGuenter Roeck * This program is free software; you can redistribute it and/or modify 779ffe859SGuenter Roeck * it under the terms of the GNU General Public License as published by 879ffe859SGuenter Roeck * the Free Software Foundation; either version 2 of the License, or 979ffe859SGuenter Roeck * (at your option) any later version. 1079ffe859SGuenter Roeck * 1179ffe859SGuenter Roeck * This program is distributed in the hope that it will be useful, 1279ffe859SGuenter Roeck * but WITHOUT ANY WARRANTY; without even the implied warranty of 1379ffe859SGuenter Roeck * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 1479ffe859SGuenter Roeck * GNU General Public License for more details. 1579ffe859SGuenter Roeck */ 1679ffe859SGuenter Roeck 1779ffe859SGuenter Roeck #include <linux/kernel.h> 1879ffe859SGuenter Roeck #include <linux/module.h> 1979ffe859SGuenter Roeck #include <linux/err.h> 2079ffe859SGuenter Roeck #include <linux/slab.h> 2179ffe859SGuenter Roeck #include <linux/bitops.h> 2279ffe859SGuenter Roeck #include <linux/i2c.h> 2379ffe859SGuenter Roeck #include <linux/hwmon.h> 2479ffe859SGuenter Roeck #include <linux/hwmon-sysfs.h> 2579ffe859SGuenter Roeck #include <linux/jiffies.h> 2679ffe859SGuenter Roeck #include <linux/regmap.h> 2779ffe859SGuenter Roeck 2879ffe859SGuenter Roeck /* chip registers */ 2979ffe859SGuenter Roeck 3079ffe859SGuenter Roeck #define LTC4222_CONTROL1 0xd0 3179ffe859SGuenter Roeck #define LTC4222_ALERT1 0xd1 3279ffe859SGuenter Roeck #define LTC4222_STATUS1 0xd2 3379ffe859SGuenter Roeck #define LTC4222_FAULT1 0xd3 3479ffe859SGuenter Roeck #define LTC4222_CONTROL2 0xd4 3579ffe859SGuenter Roeck #define LTC4222_ALERT2 0xd5 3679ffe859SGuenter Roeck #define LTC4222_STATUS2 0xd6 3779ffe859SGuenter Roeck #define LTC4222_FAULT2 0xd7 3879ffe859SGuenter Roeck #define LTC4222_SOURCE1 0xd8 3979ffe859SGuenter Roeck #define LTC4222_SOURCE2 0xda 4079ffe859SGuenter Roeck #define LTC4222_ADIN1 0xdc 4179ffe859SGuenter Roeck #define LTC4222_ADIN2 0xde 4279ffe859SGuenter Roeck #define LTC4222_SENSE1 0xe0 4379ffe859SGuenter Roeck #define LTC4222_SENSE2 0xe2 4479ffe859SGuenter Roeck #define LTC4222_ADC_CONTROL 0xe4 4579ffe859SGuenter Roeck 4679ffe859SGuenter Roeck /* 4779ffe859SGuenter Roeck * Fault register bits 4879ffe859SGuenter Roeck */ 4979ffe859SGuenter Roeck #define FAULT_OV BIT(0) 5079ffe859SGuenter Roeck #define FAULT_UV BIT(1) 5179ffe859SGuenter Roeck #define FAULT_OC BIT(2) 5279ffe859SGuenter Roeck #define FAULT_POWER_BAD BIT(3) 5379ffe859SGuenter Roeck #define FAULT_FET_BAD BIT(5) 5479ffe859SGuenter Roeck 5579ffe859SGuenter Roeck /* Return the voltage from the given register in mV or mA */ 5679ffe859SGuenter Roeck static int ltc4222_get_value(struct device *dev, u8 reg) 5779ffe859SGuenter Roeck { 5879ffe859SGuenter Roeck struct regmap *regmap = dev_get_drvdata(dev); 5979ffe859SGuenter Roeck unsigned int val; 6079ffe859SGuenter Roeck u8 buf[2]; 6179ffe859SGuenter Roeck int ret; 6279ffe859SGuenter Roeck 6379ffe859SGuenter Roeck ret = regmap_bulk_read(regmap, reg, buf, 2); 6479ffe859SGuenter Roeck if (ret < 0) 6579ffe859SGuenter Roeck return ret; 6679ffe859SGuenter Roeck 6779ffe859SGuenter Roeck val = ((buf[0] << 8) + buf[1]) >> 6; 6879ffe859SGuenter Roeck 6979ffe859SGuenter Roeck switch (reg) { 7079ffe859SGuenter Roeck case LTC4222_ADIN1: 7179ffe859SGuenter Roeck case LTC4222_ADIN2: 7279ffe859SGuenter Roeck /* 1.25 mV resolution. Convert to mV. */ 7379ffe859SGuenter Roeck val = DIV_ROUND_CLOSEST(val * 5, 4); 7479ffe859SGuenter Roeck break; 7579ffe859SGuenter Roeck case LTC4222_SOURCE1: 7679ffe859SGuenter Roeck case LTC4222_SOURCE2: 7779ffe859SGuenter Roeck /* 31.25 mV resolution. Convert to mV. */ 7879ffe859SGuenter Roeck val = DIV_ROUND_CLOSEST(val * 125, 4); 7979ffe859SGuenter Roeck break; 8079ffe859SGuenter Roeck case LTC4222_SENSE1: 8179ffe859SGuenter Roeck case LTC4222_SENSE2: 8279ffe859SGuenter Roeck /* 8379ffe859SGuenter Roeck * 62.5 uV resolution. Convert to current as measured with 8479ffe859SGuenter Roeck * an 1 mOhm sense resistor, in mA. If a different sense 8579ffe859SGuenter Roeck * resistor is installed, calculate the actual current by 8679ffe859SGuenter Roeck * dividing the reported current by the sense resistor value 8779ffe859SGuenter Roeck * in mOhm. 8879ffe859SGuenter Roeck */ 8979ffe859SGuenter Roeck val = DIV_ROUND_CLOSEST(val * 125, 2); 9079ffe859SGuenter Roeck break; 9179ffe859SGuenter Roeck default: 9279ffe859SGuenter Roeck return -EINVAL; 9379ffe859SGuenter Roeck } 9479ffe859SGuenter Roeck return val; 9579ffe859SGuenter Roeck } 9679ffe859SGuenter Roeck 97*ae868a29SGuenter Roeck static ssize_t ltc4222_value_show(struct device *dev, 9879ffe859SGuenter Roeck struct device_attribute *da, char *buf) 9979ffe859SGuenter Roeck { 10079ffe859SGuenter Roeck struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 10179ffe859SGuenter Roeck int value; 10279ffe859SGuenter Roeck 10379ffe859SGuenter Roeck value = ltc4222_get_value(dev, attr->index); 10479ffe859SGuenter Roeck if (value < 0) 10579ffe859SGuenter Roeck return value; 10679ffe859SGuenter Roeck return snprintf(buf, PAGE_SIZE, "%d\n", value); 10779ffe859SGuenter Roeck } 10879ffe859SGuenter Roeck 109*ae868a29SGuenter Roeck static ssize_t ltc4222_bool_show(struct device *dev, 11079ffe859SGuenter Roeck struct device_attribute *da, char *buf) 11179ffe859SGuenter Roeck { 11279ffe859SGuenter Roeck struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da); 11379ffe859SGuenter Roeck struct regmap *regmap = dev_get_drvdata(dev); 11479ffe859SGuenter Roeck unsigned int fault; 11579ffe859SGuenter Roeck int ret; 11679ffe859SGuenter Roeck 11779ffe859SGuenter Roeck ret = regmap_read(regmap, attr->nr, &fault); 11879ffe859SGuenter Roeck if (ret < 0) 11979ffe859SGuenter Roeck return ret; 12079ffe859SGuenter Roeck fault &= attr->index; 12179ffe859SGuenter Roeck if (fault) /* Clear reported faults in chip register */ 12279ffe859SGuenter Roeck regmap_update_bits(regmap, attr->nr, attr->index, 0); 12379ffe859SGuenter Roeck 12479ffe859SGuenter Roeck return snprintf(buf, PAGE_SIZE, "%d\n", !!fault); 12579ffe859SGuenter Roeck } 12679ffe859SGuenter Roeck 12779ffe859SGuenter Roeck /* Voltages */ 128*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_RO(in1_input, ltc4222_value, LTC4222_SOURCE1); 129*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_RO(in2_input, ltc4222_value, LTC4222_ADIN1); 130*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_RO(in3_input, ltc4222_value, LTC4222_SOURCE2); 131*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_RO(in4_input, ltc4222_value, LTC4222_ADIN2); 13279ffe859SGuenter Roeck 13379ffe859SGuenter Roeck /* 13479ffe859SGuenter Roeck * Voltage alarms 13579ffe859SGuenter Roeck * UV/OV faults are associated with the input voltage, and power bad and fet 13679ffe859SGuenter Roeck * faults are associated with the output voltage. 13779ffe859SGuenter Roeck */ 138*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_2_RO(in1_min_alarm, ltc4222_bool, LTC4222_FAULT1, 139*ae868a29SGuenter Roeck FAULT_UV); 140*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_2_RO(in1_max_alarm, ltc4222_bool, LTC4222_FAULT1, 141*ae868a29SGuenter Roeck FAULT_OV); 142*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_2_RO(in2_alarm, ltc4222_bool, LTC4222_FAULT1, 143*ae868a29SGuenter Roeck FAULT_POWER_BAD | FAULT_FET_BAD); 14479ffe859SGuenter Roeck 145*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_2_RO(in3_min_alarm, ltc4222_bool, LTC4222_FAULT2, 146*ae868a29SGuenter Roeck FAULT_UV); 147*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_2_RO(in3_max_alarm, ltc4222_bool, LTC4222_FAULT2, 148*ae868a29SGuenter Roeck FAULT_OV); 149*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_2_RO(in4_alarm, ltc4222_bool, LTC4222_FAULT2, 150*ae868a29SGuenter Roeck FAULT_POWER_BAD | FAULT_FET_BAD); 15179ffe859SGuenter Roeck 15279ffe859SGuenter Roeck /* Current (via sense resistor) */ 153*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc4222_value, LTC4222_SENSE1); 154*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc4222_value, LTC4222_SENSE2); 15579ffe859SGuenter Roeck 15679ffe859SGuenter Roeck /* Overcurrent alarm */ 157*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_2_RO(curr1_max_alarm, ltc4222_bool, LTC4222_FAULT1, 158*ae868a29SGuenter Roeck FAULT_OC); 159*ae868a29SGuenter Roeck static SENSOR_DEVICE_ATTR_2_RO(curr2_max_alarm, ltc4222_bool, LTC4222_FAULT2, 160*ae868a29SGuenter Roeck FAULT_OC); 16179ffe859SGuenter Roeck 16279ffe859SGuenter Roeck static struct attribute *ltc4222_attrs[] = { 16379ffe859SGuenter Roeck &sensor_dev_attr_in1_input.dev_attr.attr, 16479ffe859SGuenter Roeck &sensor_dev_attr_in1_min_alarm.dev_attr.attr, 16579ffe859SGuenter Roeck &sensor_dev_attr_in1_max_alarm.dev_attr.attr, 16679ffe859SGuenter Roeck &sensor_dev_attr_in2_input.dev_attr.attr, 16779ffe859SGuenter Roeck &sensor_dev_attr_in2_alarm.dev_attr.attr, 16879ffe859SGuenter Roeck &sensor_dev_attr_in3_input.dev_attr.attr, 16979ffe859SGuenter Roeck &sensor_dev_attr_in3_min_alarm.dev_attr.attr, 17079ffe859SGuenter Roeck &sensor_dev_attr_in3_max_alarm.dev_attr.attr, 17179ffe859SGuenter Roeck &sensor_dev_attr_in4_input.dev_attr.attr, 17279ffe859SGuenter Roeck &sensor_dev_attr_in4_alarm.dev_attr.attr, 17379ffe859SGuenter Roeck 17479ffe859SGuenter Roeck &sensor_dev_attr_curr1_input.dev_attr.attr, 17579ffe859SGuenter Roeck &sensor_dev_attr_curr1_max_alarm.dev_attr.attr, 17679ffe859SGuenter Roeck &sensor_dev_attr_curr2_input.dev_attr.attr, 17779ffe859SGuenter Roeck &sensor_dev_attr_curr2_max_alarm.dev_attr.attr, 17879ffe859SGuenter Roeck 17979ffe859SGuenter Roeck NULL, 18079ffe859SGuenter Roeck }; 18179ffe859SGuenter Roeck ATTRIBUTE_GROUPS(ltc4222); 18279ffe859SGuenter Roeck 183034b44b4SAxel Lin static const struct regmap_config ltc4222_regmap_config = { 18479ffe859SGuenter Roeck .reg_bits = 8, 18579ffe859SGuenter Roeck .val_bits = 8, 18679ffe859SGuenter Roeck .max_register = LTC4222_ADC_CONTROL, 18779ffe859SGuenter Roeck }; 18879ffe859SGuenter Roeck 18979ffe859SGuenter Roeck static int ltc4222_probe(struct i2c_client *client, 19079ffe859SGuenter Roeck const struct i2c_device_id *id) 19179ffe859SGuenter Roeck { 19279ffe859SGuenter Roeck struct device *dev = &client->dev; 19379ffe859SGuenter Roeck struct device *hwmon_dev; 19479ffe859SGuenter Roeck struct regmap *regmap; 19579ffe859SGuenter Roeck 19679ffe859SGuenter Roeck regmap = devm_regmap_init_i2c(client, <c4222_regmap_config); 19779ffe859SGuenter Roeck if (IS_ERR(regmap)) { 19879ffe859SGuenter Roeck dev_err(dev, "failed to allocate register map\n"); 19979ffe859SGuenter Roeck return PTR_ERR(regmap); 20079ffe859SGuenter Roeck } 20179ffe859SGuenter Roeck 20279ffe859SGuenter Roeck /* Clear faults */ 20379ffe859SGuenter Roeck regmap_write(regmap, LTC4222_FAULT1, 0x00); 20479ffe859SGuenter Roeck regmap_write(regmap, LTC4222_FAULT2, 0x00); 20579ffe859SGuenter Roeck 20679ffe859SGuenter Roeck hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 20779ffe859SGuenter Roeck regmap, 20879ffe859SGuenter Roeck ltc4222_groups); 20979ffe859SGuenter Roeck return PTR_ERR_OR_ZERO(hwmon_dev); 21079ffe859SGuenter Roeck } 21179ffe859SGuenter Roeck 21279ffe859SGuenter Roeck static const struct i2c_device_id ltc4222_id[] = { 21379ffe859SGuenter Roeck {"ltc4222", 0}, 21479ffe859SGuenter Roeck { } 21579ffe859SGuenter Roeck }; 21679ffe859SGuenter Roeck 21779ffe859SGuenter Roeck MODULE_DEVICE_TABLE(i2c, ltc4222_id); 21879ffe859SGuenter Roeck 21979ffe859SGuenter Roeck static struct i2c_driver ltc4222_driver = { 22079ffe859SGuenter Roeck .driver = { 22179ffe859SGuenter Roeck .name = "ltc4222", 22279ffe859SGuenter Roeck }, 22379ffe859SGuenter Roeck .probe = ltc4222_probe, 22479ffe859SGuenter Roeck .id_table = ltc4222_id, 22579ffe859SGuenter Roeck }; 22679ffe859SGuenter Roeck 22779ffe859SGuenter Roeck module_i2c_driver(ltc4222_driver); 22879ffe859SGuenter Roeck 22979ffe859SGuenter Roeck MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); 23079ffe859SGuenter Roeck MODULE_DESCRIPTION("LTC4222 driver"); 23179ffe859SGuenter Roeck MODULE_LICENSE("GPL"); 232