| /* |
| * Driver for Linear Technology LTC2945 I2C Power Monitor |
| * |
| * Copyright (c) 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 |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * 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. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/err.h> |
| #include <linux/slab.h> |
| #include <linux/i2c.h> |
| #include <linux/hwmon.h> |
| #include <linux/hwmon-sysfs.h> |
| #include <linux/jiffies.h> |
| #include <linux/regmap.h> |
| |
| /* chip registers */ |
| #define LTC2945_CONTROL 0x00 |
| #define LTC2945_ALERT 0x01 |
| #define LTC2945_STATUS 0x02 |
| #define LTC2945_FAULT 0x03 |
| #define LTC2945_POWER_H 0x05 |
| #define LTC2945_MAX_POWER_H 0x08 |
| #define LTC2945_MIN_POWER_H 0x0b |
| #define LTC2945_MAX_POWER_THRES_H 0x0e |
| #define LTC2945_MIN_POWER_THRES_H 0x11 |
| #define LTC2945_SENSE_H 0x14 |
| #define LTC2945_MAX_SENSE_H 0x16 |
| #define LTC2945_MIN_SENSE_H 0x18 |
| #define LTC2945_MAX_SENSE_THRES_H 0x1a |
| #define LTC2945_MIN_SENSE_THRES_H 0x1c |
| #define LTC2945_VIN_H 0x1e |
| #define LTC2945_MAX_VIN_H 0x20 |
| #define LTC2945_MIN_VIN_H 0x22 |
| #define LTC2945_MAX_VIN_THRES_H 0x24 |
| #define LTC2945_MIN_VIN_THRES_H 0x26 |
| #define LTC2945_ADIN_H 0x28 |
| #define LTC2945_MAX_ADIN_H 0x2a |
| #define LTC2945_MIN_ADIN_H 0x2c |
| #define LTC2945_MAX_ADIN_THRES_H 0x2e |
| #define LTC2945_MIN_ADIN_THRES_H 0x30 |
| #define LTC2945_MIN_ADIN_THRES_L 0x31 |
| |
| /* Fault register bits */ |
| |
| #define FAULT_ADIN_UV (1 << 0) |
| #define FAULT_ADIN_OV (1 << 1) |
| #define FAULT_VIN_UV (1 << 2) |
| #define FAULT_VIN_OV (1 << 3) |
| #define FAULT_SENSE_UV (1 << 4) |
| #define FAULT_SENSE_OV (1 << 5) |
| #define FAULT_POWER_UV (1 << 6) |
| #define FAULT_POWER_OV (1 << 7) |
| |
| /* Control register bits */ |
| |
| #define CONTROL_MULT_SELECT (1 << 0) |
| #define CONTROL_TEST_MODE (1 << 4) |
| |
| static inline bool is_power_reg(u8 reg) |
| { |
| return reg < LTC2945_SENSE_H; |
| } |
| |
| /* Return the value from the given register in uW, mV, or mA */ |
| static long long ltc2945_reg_to_val(struct device *dev, u8 reg) |
| { |
| struct regmap *regmap = dev_get_drvdata(dev); |
| unsigned int control; |
| u8 buf[3]; |
| long long val; |
| int ret; |
| |
| ret = regmap_bulk_read(regmap, reg, buf, |
| is_power_reg(reg) ? 3 : 2); |
| if (ret < 0) |
| return ret; |
| |
| if (is_power_reg(reg)) { |
| /* power */ |
| val = (buf[0] << 16) + (buf[1] << 8) + buf[2]; |
| } else { |
| /* current, voltage */ |
| val = (buf[0] << 4) + (buf[1] >> 4); |
| } |
| |
| switch (reg) { |
| case LTC2945_POWER_H: |
| case LTC2945_MAX_POWER_H: |
| case LTC2945_MIN_POWER_H: |
| case LTC2945_MAX_POWER_THRES_H: |
| case LTC2945_MIN_POWER_THRES_H: |
| /* |
| * Convert to uW by assuming current is measured with |
| * an 1mOhm sense resistor, similar to current |
| * measurements. |
| * Control register bit 0 selects if voltage at SENSE+/VDD |
| * or voltage at ADIN is used to measure power. |
| */ |
| ret = regmap_read(regmap, LTC2945_CONTROL, &control); |
| if (ret < 0) |
| return ret; |
| if (control & CONTROL_MULT_SELECT) { |
| /* 25 mV * 25 uV = 0.625 uV resolution. */ |
| val *= 625LL; |
| } else { |
| /* 0.5 mV * 25 uV = 0.0125 uV resolution. */ |
| val = (val * 25LL) >> 1; |
| } |
| break; |
| case LTC2945_VIN_H: |
| case LTC2945_MAX_VIN_H: |
| case LTC2945_MIN_VIN_H: |
| case LTC2945_MAX_VIN_THRES_H: |
| case LTC2945_MIN_VIN_THRES_H: |
| /* 25 mV resolution. Convert to mV. */ |
| val *= 25; |
| break; |
| case LTC2945_ADIN_H: |
| case LTC2945_MAX_ADIN_H: |
| case LTC2945_MIN_ADIN_THRES_H: |
| case LTC2945_MAX_ADIN_THRES_H: |
| case LTC2945_MIN_ADIN_H: |
| /* 0.5mV resolution. Convert to mV. */ |
| val = val >> 1; |
| break; |
| case LTC2945_SENSE_H: |
| case LTC2945_MAX_SENSE_H: |
| case LTC2945_MIN_SENSE_H: |
| case LTC2945_MAX_SENSE_THRES_H: |
| case LTC2945_MIN_SENSE_THRES_H: |
| /* |
| * 25 uV resolution. Convert to current as measured with |
| * an 1 mOhm sense resistor, in mA. If a different sense |
| * resistor is installed, calculate the actual current by |
| * dividing the reported current by the sense resistor value |
| * in mOhm. |
| */ |
| val *= 25; |
| break; |
| default: |
| return -EINVAL; |
| } |
| return val; |
| } |
| |
| static int ltc2945_val_to_reg(struct device *dev, u8 reg, |
| unsigned long val) |
| { |
| struct regmap *regmap = dev_get_drvdata(dev); |
| unsigned int control; |
| int ret; |
| |
| switch (reg) { |
| case LTC2945_POWER_H: |
| case LTC2945_MAX_POWER_H: |
| case LTC2945_MIN_POWER_H: |
| case LTC2945_MAX_POWER_THRES_H: |
| case LTC2945_MIN_POWER_THRES_H: |
| /* |
| * Convert to register value by assuming current is measured |
| * with an 1mOhm sense resistor, similar to current |
| * measurements. |
| * Control register bit 0 selects if voltage at SENSE+/VDD |
| * or voltage at ADIN is used to measure power, which in turn |
| * determines register calculations. |
| */ |
| ret = regmap_read(regmap, LTC2945_CONTROL, &control); |
| if (ret < 0) |
| return ret; |
| if (control & CONTROL_MULT_SELECT) { |
| /* 25 mV * 25 uV = 0.625 uV resolution. */ |
| val = DIV_ROUND_CLOSEST(val, 625); |
| } else { |
| /* |
| * 0.5 mV * 25 uV = 0.0125 uV resolution. |
| * Divide first to avoid overflow; |
| * accept loss of accuracy. |
| */ |
| val = DIV_ROUND_CLOSEST(val, 25) * 2; |
| } |
| break; |
| case LTC2945_VIN_H: |
| case LTC2945_MAX_VIN_H: |
| case LTC2945_MIN_VIN_H: |
| case LTC2945_MAX_VIN_THRES_H: |
| case LTC2945_MIN_VIN_THRES_H: |
| /* 25 mV resolution. */ |
| val /= 25; |
| break; |
| case LTC2945_ADIN_H: |
| case LTC2945_MAX_ADIN_H: |
| case LTC2945_MIN_ADIN_THRES_H: |
| case LTC2945_MAX_ADIN_THRES_H: |
| case LTC2945_MIN_ADIN_H: |
| /* 0.5mV resolution. */ |
| val *= 2; |
| break; |
| case LTC2945_SENSE_H: |
| case LTC2945_MAX_SENSE_H: |
| case LTC2945_MIN_SENSE_H: |
| case LTC2945_MAX_SENSE_THRES_H: |
| case LTC2945_MIN_SENSE_THRES_H: |
| /* |
| * 25 uV resolution. Convert to current as measured with |
| * an 1 mOhm sense resistor, in mA. If a different sense |
| * resistor is installed, calculate the actual current by |
| * dividing the reported current by the sense resistor value |
| * in mOhm. |
| */ |
| val = DIV_ROUND_CLOSEST(val, 25); |
| break; |
| default: |
| return -EINVAL; |
| } |
| return val; |
| } |
| |
| static ssize_t ltc2945_show_value(struct device *dev, |
| struct device_attribute *da, char *buf) |
| { |
| struct sensor_device_attribute *attr = to_sensor_dev_attr(da); |
| long long value; |
| |
| value = ltc2945_reg_to_val(dev, attr->index); |
| if (value < 0) |
| return value; |
| return snprintf(buf, PAGE_SIZE, "%lld\n", value); |
| } |
| |
| static ssize_t ltc2945_set_value(struct device *dev, |
| struct device_attribute *da, |
| const char *buf, size_t count) |
| { |
| struct sensor_device_attribute *attr = to_sensor_dev_attr(da); |
| struct regmap *regmap = dev_get_drvdata(dev); |
| u8 reg = attr->index; |
| unsigned long val; |
| u8 regbuf[3]; |
| int num_regs; |
| int regval; |
| int ret; |
| |
| ret = kstrtoul(buf, 10, &val); |
| if (ret) |
| return ret; |
| |
| /* convert to register value, then clamp and write result */ |
| regval = ltc2945_val_to_reg(dev, reg, val); |
| if (regval < 0) |
| return regval; |
| if (is_power_reg(reg)) { |
| regval = clamp_val(regval, 0, 0xffffff); |
| regbuf[0] = regval >> 16; |
| regbuf[1] = (regval >> 8) & 0xff; |
| regbuf[2] = regval; |
| num_regs = 3; |
| } else { |
| regval = clamp_val(regval, 0, 0xfff) << 4; |
| regbuf[0] = regval >> 8; |
| regbuf[1] = regval & 0xff; |
| num_regs = 2; |
| } |
| ret = regmap_bulk_write(regmap, reg, regbuf, num_regs); |
| return ret < 0 ? ret : count; |
| } |
| |
| static ssize_t ltc2945_reset_history(struct device *dev, |
| struct device_attribute *da, |
| const char *buf, size_t count) |
| { |
| struct sensor_device_attribute *attr = to_sensor_dev_attr(da); |
| struct regmap *regmap = dev_get_drvdata(dev); |
| u8 reg = attr->index; |
| int num_regs = is_power_reg(reg) ? 3 : 2; |
| u8 buf_min[3] = { 0xff, 0xff, 0xff }; |
| u8 buf_max[3] = { 0, 0, 0 }; |
| unsigned long val; |
| int ret; |
| |
| ret = kstrtoul(buf, 10, &val); |
| if (ret) |
| return ret; |
| if (val != 1) |
| return -EINVAL; |
| |
| ret = regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE, |
| CONTROL_TEST_MODE); |
| |
| /* Reset minimum */ |
| ret = regmap_bulk_write(regmap, reg, buf_min, num_regs); |
| if (ret) |
| return ret; |
| |
| switch (reg) { |
| case LTC2945_MIN_POWER_H: |
| reg = LTC2945_MAX_POWER_H; |
| break; |
| case LTC2945_MIN_SENSE_H: |
| reg = LTC2945_MAX_SENSE_H; |
| break; |
| case LTC2945_MIN_VIN_H: |
| reg = LTC2945_MAX_VIN_H; |
| break; |
| case LTC2945_MIN_ADIN_H: |
| reg = LTC2945_MAX_ADIN_H; |
| break; |
| default: |
| WARN_ONCE(1, "Bad register: 0x%x\n", reg); |
| return -EINVAL; |
| } |
| /* Reset maximum */ |
| ret = regmap_bulk_write(regmap, reg, buf_max, num_regs); |
| |
| /* Try resetting test mode even if there was an error */ |
| regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE, 0); |
| |
| return ret ? : count; |
| } |
| |
| static ssize_t ltc2945_show_bool(struct device *dev, |
| struct device_attribute *da, char *buf) |
| { |
| struct sensor_device_attribute *attr = to_sensor_dev_attr(da); |
| struct regmap *regmap = dev_get_drvdata(dev); |
| unsigned int fault; |
| int ret; |
| |
| ret = regmap_read(regmap, LTC2945_FAULT, &fault); |
| if (ret < 0) |
| return ret; |
| |
| fault &= attr->index; |
| if (fault) /* Clear reported faults in chip register */ |
| regmap_update_bits(regmap, LTC2945_FAULT, attr->index, 0); |
| |
| return snprintf(buf, PAGE_SIZE, "%d\n", !!fault); |
| } |
| |
| /* Input voltages */ |
| |
| static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc2945_show_value, NULL, |
| LTC2945_VIN_H); |
| static SENSOR_DEVICE_ATTR(in1_min, S_IRUGO | S_IWUSR, ltc2945_show_value, |
| ltc2945_set_value, LTC2945_MIN_VIN_THRES_H); |
| static SENSOR_DEVICE_ATTR(in1_max, S_IRUGO | S_IWUSR, ltc2945_show_value, |
| ltc2945_set_value, LTC2945_MAX_VIN_THRES_H); |
| static SENSOR_DEVICE_ATTR(in1_lowest, S_IRUGO, ltc2945_show_value, NULL, |
| LTC2945_MIN_VIN_H); |
| static SENSOR_DEVICE_ATTR(in1_highest, S_IRUGO, ltc2945_show_value, NULL, |
| LTC2945_MAX_VIN_H); |
| static SENSOR_DEVICE_ATTR(in1_reset_history, S_IWUSR, NULL, |
| ltc2945_reset_history, LTC2945_MIN_VIN_H); |
| |
| static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc2945_show_value, NULL, |
| LTC2945_ADIN_H); |
| static SENSOR_DEVICE_ATTR(in2_min, S_IRUGO | S_IWUSR, ltc2945_show_value, |
| ltc2945_set_value, LTC2945_MIN_ADIN_THRES_H); |
| static SENSOR_DEVICE_ATTR(in2_max, S_IRUGO | S_IWUSR, ltc2945_show_value, |
| ltc2945_set_value, LTC2945_MAX_ADIN_THRES_H); |
| static SENSOR_DEVICE_ATTR(in2_lowest, S_IRUGO, ltc2945_show_value, NULL, |
| LTC2945_MIN_ADIN_H); |
| static SENSOR_DEVICE_ATTR(in2_highest, S_IRUGO, ltc2945_show_value, NULL, |
| LTC2945_MAX_ADIN_H); |
| static SENSOR_DEVICE_ATTR(in2_reset_history, S_IWUSR, NULL, |
| ltc2945_reset_history, LTC2945_MIN_ADIN_H); |
| |
| /* Voltage alarms */ |
| |
| static SENSOR_DEVICE_ATTR(in1_min_alarm, S_IRUGO, ltc2945_show_bool, NULL, |
| FAULT_VIN_UV); |
| static SENSOR_DEVICE_ATTR(in1_max_alarm, S_IRUGO, ltc2945_show_bool, NULL, |
| FAULT_VIN_OV); |
| static SENSOR_DEVICE_ATTR(in2_min_alarm, S_IRUGO, ltc2945_show_bool, NULL, |
| FAULT_ADIN_UV); |
| static SENSOR_DEVICE_ATTR(in2_max_alarm, S_IRUGO, ltc2945_show_bool, NULL, |
| FAULT_ADIN_OV); |
| |
| /* Currents (via sense resistor) */ |
| |
| static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc2945_show_value, NULL, |
| LTC2945_SENSE_H); |
| static SENSOR_DEVICE_ATTR(curr1_min, S_IRUGO | S_IWUSR, ltc2945_show_value, |
| ltc2945_set_value, LTC2945_MIN_SENSE_THRES_H); |
| static SENSOR_DEVICE_ATTR(curr1_max, S_IRUGO | S_IWUSR, ltc2945_show_value, |
| ltc2945_set_value, LTC2945_MAX_SENSE_THRES_H); |
| static SENSOR_DEVICE_ATTR(curr1_lowest, S_IRUGO, ltc2945_show_value, NULL, |
| LTC2945_MIN_SENSE_H); |
| static SENSOR_DEVICE_ATTR(curr1_highest, S_IRUGO, ltc2945_show_value, NULL, |
| LTC2945_MAX_SENSE_H); |
| static SENSOR_DEVICE_ATTR(curr1_reset_history, S_IWUSR, NULL, |
| ltc2945_reset_history, LTC2945_MIN_SENSE_H); |
| |
| /* Current alarms */ |
| |
| static SENSOR_DEVICE_ATTR(curr1_min_alarm, S_IRUGO, ltc2945_show_bool, NULL, |
| FAULT_SENSE_UV); |
| static SENSOR_DEVICE_ATTR(curr1_max_alarm, S_IRUGO, ltc2945_show_bool, NULL, |
| FAULT_SENSE_OV); |
| |
| /* Power */ |
| |
| static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ltc2945_show_value, NULL, |
| LTC2945_POWER_H); |
| static SENSOR_DEVICE_ATTR(power1_min, S_IRUGO | S_IWUSR, ltc2945_show_value, |
| ltc2945_set_value, LTC2945_MIN_POWER_THRES_H); |
| static SENSOR_DEVICE_ATTR(power1_max, S_IRUGO | S_IWUSR, ltc2945_show_value, |
| ltc2945_set_value, LTC2945_MAX_POWER_THRES_H); |
| static SENSOR_DEVICE_ATTR(power1_input_lowest, S_IRUGO, ltc2945_show_value, |
| NULL, LTC2945_MIN_POWER_H); |
| static SENSOR_DEVICE_ATTR(power1_input_highest, S_IRUGO, ltc2945_show_value, |
| NULL, LTC2945_MAX_POWER_H); |
| static SENSOR_DEVICE_ATTR(power1_reset_history, S_IWUSR, NULL, |
| ltc2945_reset_history, LTC2945_MIN_POWER_H); |
| |
| /* Power alarms */ |
| |
| static SENSOR_DEVICE_ATTR(power1_min_alarm, S_IRUGO, ltc2945_show_bool, NULL, |
| FAULT_POWER_UV); |
| static SENSOR_DEVICE_ATTR(power1_max_alarm, S_IRUGO, ltc2945_show_bool, NULL, |
| FAULT_POWER_OV); |
| |
| static struct attribute *ltc2945_attrs[] = { |
| &sensor_dev_attr_in1_input.dev_attr.attr, |
| &sensor_dev_attr_in1_min.dev_attr.attr, |
| &sensor_dev_attr_in1_max.dev_attr.attr, |
| &sensor_dev_attr_in1_lowest.dev_attr.attr, |
| &sensor_dev_attr_in1_highest.dev_attr.attr, |
| &sensor_dev_attr_in1_reset_history.dev_attr.attr, |
| &sensor_dev_attr_in1_min_alarm.dev_attr.attr, |
| &sensor_dev_attr_in1_max_alarm.dev_attr.attr, |
| |
| &sensor_dev_attr_in2_input.dev_attr.attr, |
| &sensor_dev_attr_in2_min.dev_attr.attr, |
| &sensor_dev_attr_in2_max.dev_attr.attr, |
| &sensor_dev_attr_in2_lowest.dev_attr.attr, |
| &sensor_dev_attr_in2_highest.dev_attr.attr, |
| &sensor_dev_attr_in2_reset_history.dev_attr.attr, |
| &sensor_dev_attr_in2_min_alarm.dev_attr.attr, |
| &sensor_dev_attr_in2_max_alarm.dev_attr.attr, |
| |
| &sensor_dev_attr_curr1_input.dev_attr.attr, |
| &sensor_dev_attr_curr1_min.dev_attr.attr, |
| &sensor_dev_attr_curr1_max.dev_attr.attr, |
| &sensor_dev_attr_curr1_lowest.dev_attr.attr, |
| &sensor_dev_attr_curr1_highest.dev_attr.attr, |
| &sensor_dev_attr_curr1_reset_history.dev_attr.attr, |
| &sensor_dev_attr_curr1_min_alarm.dev_attr.attr, |
| &sensor_dev_attr_curr1_max_alarm.dev_attr.attr, |
| |
| &sensor_dev_attr_power1_input.dev_attr.attr, |
| &sensor_dev_attr_power1_min.dev_attr.attr, |
| &sensor_dev_attr_power1_max.dev_attr.attr, |
| &sensor_dev_attr_power1_input_lowest.dev_attr.attr, |
| &sensor_dev_attr_power1_input_highest.dev_attr.attr, |
| &sensor_dev_attr_power1_reset_history.dev_attr.attr, |
| &sensor_dev_attr_power1_min_alarm.dev_attr.attr, |
| &sensor_dev_attr_power1_max_alarm.dev_attr.attr, |
| |
| NULL, |
| }; |
| ATTRIBUTE_GROUPS(ltc2945); |
| |
| static const struct regmap_config ltc2945_regmap_config = { |
| .reg_bits = 8, |
| .val_bits = 8, |
| .max_register = LTC2945_MIN_ADIN_THRES_L, |
| }; |
| |
| static int ltc2945_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct device *dev = &client->dev; |
| struct device *hwmon_dev; |
| struct regmap *regmap; |
| |
| regmap = devm_regmap_init_i2c(client, <c2945_regmap_config); |
| if (IS_ERR(regmap)) { |
| dev_err(dev, "failed to allocate register map\n"); |
| return PTR_ERR(regmap); |
| } |
| |
| /* Clear faults */ |
| regmap_write(regmap, LTC2945_FAULT, 0x00); |
| |
| hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, |
| regmap, |
| ltc2945_groups); |
| return PTR_ERR_OR_ZERO(hwmon_dev); |
| } |
| |
| static const struct i2c_device_id ltc2945_id[] = { |
| {"ltc2945", 0}, |
| { } |
| }; |
| |
| MODULE_DEVICE_TABLE(i2c, ltc2945_id); |
| |
| static struct i2c_driver ltc2945_driver = { |
| .driver = { |
| .name = "ltc2945", |
| }, |
| .probe = ltc2945_probe, |
| .id_table = ltc2945_id, |
| }; |
| |
| module_i2c_driver(ltc2945_driver); |
| |
| MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); |
| MODULE_DESCRIPTION("LTC2945 driver"); |
| MODULE_LICENSE("GPL"); |