/* * 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 #include #include #include #include #include #include #include #include /* 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 "); MODULE_DESCRIPTION("LTC2945 driver"); MODULE_LICENSE("GPL");