diff options
Diffstat (limited to 'drivers/hwmon/ltc2945.c')
| -rw-r--r-- | drivers/hwmon/ltc2945.c | 519 |
1 files changed, 519 insertions, 0 deletions
diff --git a/drivers/hwmon/ltc2945.c b/drivers/hwmon/ltc2945.c new file mode 100644 index 000000000000..c104cc32989d --- /dev/null +++ b/drivers/hwmon/ltc2945.c @@ -0,0 +1,519 @@ +/* + * 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 (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: + BUG(); + break; + } + /* 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 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"); |