/* * Driver for Texas Instruments INA219, INA226 power monitor chips * * INA219: * Zero Drift Bi-Directional Current/Power Monitor with I2C Interface * Datasheet: http://www.ti.com/product/ina219 * * INA226: * Bi-Directional Current/Power Monitor with I2C Interface * Datasheet: http://www.ti.com/product/ina226 * * Copyright (C) 2012 Lothar Felten <l-felten@ti.com> * Thanks to Jan Volkering * * 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; version 2 of the License. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/err.h> #include <linux/slab.h> #include <linux/i2c.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/platform_data/ina2xx.h> /* common register definitions */ #define INA2XX_CONFIG 0x00 #define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */ #define INA2XX_BUS_VOLTAGE 0x02 /* readonly */ #define INA2XX_POWER 0x03 /* readonly */ #define INA2XX_CURRENT 0x04 /* readonly */ #define INA2XX_CALIBRATION 0x05 /* INA226 register definitions */ #define INA226_MASK_ENABLE 0x06 #define INA226_ALERT_LIMIT 0x07 #define INA226_DIE_ID 0xFF /* register count */ #define INA219_REGISTERS 6 #define INA226_REGISTERS 8 #define INA2XX_MAX_REGISTERS 8 /* settings - depend on use case */ #define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */ #define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */ /* worst case is 68.10 ms (~14.6Hz, ina219) */ #define INA2XX_CONVERSION_RATE 15 enum ina2xx_ids { ina219, ina226 }; struct ina2xx_data { struct device *hwmon_dev; struct mutex update_lock; bool valid; unsigned long last_updated; int kind; int registers; u16 regs[INA2XX_MAX_REGISTERS]; }; int ina2xx_read_word(struct i2c_client *client, int reg) { int val = i2c_smbus_read_word_data(client, reg); if (unlikely(val < 0)) { dev_dbg(&client->dev, "Failed to read register: %d\n", reg); return val; } return be16_to_cpu(val); } void ina2xx_write_word(struct i2c_client *client, int reg, int data) { i2c_smbus_write_word_data(client, reg, cpu_to_be16(data)); } static struct ina2xx_data *ina2xx_update_device(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct ina2xx_data *data = i2c_get_clientdata(client); struct ina2xx_data *ret = data; mutex_lock(&data->update_lock); if (time_after(jiffies, data->last_updated + HZ / INA2XX_CONVERSION_RATE) || !data->valid) { int i; dev_dbg(&client->dev, "Starting ina2xx update\n"); /* Read all registers */ for (i = 0; i < data->registers; i++) { int rv = ina2xx_read_word(client, i); if (rv < 0) { ret = ERR_PTR(rv); goto abort; } data->regs[i] = rv; } data->last_updated = jiffies; data->valid = 1; } abort: mutex_unlock(&data->update_lock); return ret; } static int ina219_get_value(struct ina2xx_data *data, u8 reg) { /* * calculate exact value for the given register * we assume default power-on reset settings: * bus voltage range 32V * gain = /8 * adc 1 & 2 -> conversion time 532uS * mode is continuous shunt and bus * calibration value is INA219_CALIBRATION_VALUE */ int val = data->regs[reg]; switch (reg) { case INA2XX_SHUNT_VOLTAGE: /* LSB=10uV. Convert to mV. */ val = DIV_ROUND_CLOSEST(val, 100); break; case INA2XX_BUS_VOLTAGE: /* LSB=4mV. Register is not right aligned, convert to mV. */ val = (val >> 3) * 4; break; case INA2XX_POWER: /* LSB=20mW. Convert to uW */ val = val * 20 * 1000; break; case INA2XX_CURRENT: /* LSB=1mA (selected). Is in mA */ break; default: /* programmer goofed */ WARN_ON_ONCE(1); val = 0; break; } return val; } static int ina226_get_value(struct ina2xx_data *data, u8 reg) { /* * calculate exact value for the given register * we assume default power-on reset settings: * bus voltage range 32V * gain = /8 * adc 1 & 2 -> conversion time 532uS * mode is continuous shunt and bus * calibration value is INA226_CALIBRATION_VALUE */ int val = data->regs[reg]; switch (reg) { case INA2XX_SHUNT_VOLTAGE: /* LSB=2.5uV. Convert to mV. */ val = DIV_ROUND_CLOSEST(val, 400); break; case INA2XX_BUS_VOLTAGE: /* LSB=1.25mV. Convert to mV. */ val = val + DIV_ROUND_CLOSEST(val, 4); break; case INA2XX_POWER: /* LSB=25mW. Convert to uW */ val = val * 25 * 1000; break; case INA2XX_CURRENT: /* LSB=1mA (selected). Is in mA */ break; default: /* programmer goofed */ WARN_ON_ONCE(1); val = 0; break; } return val; } static ssize_t ina2xx_show_value(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct ina2xx_data *data = ina2xx_update_device(dev); int value = 0; if (IS_ERR(data)) return PTR_ERR(data); switch (data->kind) { case ina219: value = ina219_get_value(data, attr->index); break; case ina226: value = ina226_get_value(data, attr->index); break; default: WARN_ON_ONCE(1); break; } return snprintf(buf, PAGE_SIZE, "%d\n", value); } /* shunt voltage */ static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, \ ina2xx_show_value, NULL, INA2XX_SHUNT_VOLTAGE); /* bus voltage */ static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, \ ina2xx_show_value, NULL, INA2XX_BUS_VOLTAGE); /* calculated current */ static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, \ ina2xx_show_value, NULL, INA2XX_CURRENT); /* calculated power */ static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, \ ina2xx_show_value, NULL, INA2XX_POWER); /* pointers to created device attributes */ static struct attribute *ina2xx_attributes[] = { &sensor_dev_attr_in0_input.dev_attr.attr, &sensor_dev_attr_in1_input.dev_attr.attr, &sensor_dev_attr_curr1_input.dev_attr.attr, &sensor_dev_attr_power1_input.dev_attr.attr, NULL, }; static const struct attribute_group ina2xx_group = { .attrs = ina2xx_attributes, }; static int ina2xx_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = client->adapter; struct ina2xx_data *data; struct ina2xx_platform_data *pdata; int ret = 0; long shunt = 10000; /* default shunt value 10mOhms */ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) return -ENODEV; data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; if (client->dev.platform_data) { pdata = (struct ina2xx_platform_data *)client->dev.platform_data; shunt = pdata->shunt_uohms; } if (shunt <= 0) return -ENODEV; /* set the device type */ data->kind = id->driver_data; switch (data->kind) { case ina219: /* device configuration */ ina2xx_write_word(client, INA2XX_CONFIG, INA219_CONFIG_DEFAULT); /* set current LSB to 1mA, shunt is in uOhms */ /* (equation 13 in datasheet) */ ina2xx_write_word(client, INA2XX_CALIBRATION, 40960000 / shunt); dev_info(&client->dev, "power monitor INA219 (Rshunt = %li uOhm)\n", shunt); data->registers = INA219_REGISTERS; break; case ina226: /* device configuration */ ina2xx_write_word(client, INA2XX_CONFIG, INA226_CONFIG_DEFAULT); /* set current LSB to 1mA, shunt is in uOhms */ /* (equation 1 in datasheet)*/ ina2xx_write_word(client, INA2XX_CALIBRATION, 5120000 / shunt); dev_info(&client->dev, "power monitor INA226 (Rshunt = %li uOhm)\n", shunt); data->registers = INA226_REGISTERS; break; default: /* unknown device id */ return -ENODEV; } i2c_set_clientdata(client, data); mutex_init(&data->update_lock); ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group); if (ret) return ret; data->hwmon_dev = hwmon_device_register(&client->dev); if (IS_ERR(data->hwmon_dev)) { ret = PTR_ERR(data->hwmon_dev); goto out_err_hwmon; } return 0; out_err_hwmon: sysfs_remove_group(&client->dev.kobj, &ina2xx_group); return ret; } static int ina2xx_remove(struct i2c_client *client) { struct ina2xx_data *data = i2c_get_clientdata(client); hwmon_device_unregister(data->hwmon_dev); sysfs_remove_group(&client->dev.kobj, &ina2xx_group); return 0; } static const struct i2c_device_id ina2xx_id[] = { { "ina219", ina219 }, { "ina226", ina226 }, { } }; MODULE_DEVICE_TABLE(i2c, ina2xx_id); static struct i2c_driver ina2xx_driver = { .driver = { .name = "ina2xx", }, .probe = ina2xx_probe, .remove = ina2xx_remove, .id_table = ina2xx_id, }; static int __init ina2xx_init(void) { return i2c_add_driver(&ina2xx_driver); } static void __exit ina2xx_exit(void) { i2c_del_driver(&ina2xx_driver); } MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>"); MODULE_DESCRIPTION("ina2xx driver"); MODULE_LICENSE("GPL"); module_init(ina2xx_init); module_exit(ina2xx_exit);