/* * 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 * * INA220: * Bi-Directional Current/Power Monitor with I2C Interface * Datasheet: http://www.ti.com/product/ina220 * * INA226: * Bi-Directional Current/Power Monitor with I2C Interface * Datasheet: http://www.ti.com/product/ina226 * * INA230: * Bi-directional Current/Power Monitor with I2C Interface * Datasheet: http://www.ti.com/product/ina230 * * 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/jiffies.h> #include <linux/of.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_config { u16 config_default; int calibration_factor; int registers; int shunt_div; int bus_voltage_shift; int bus_voltage_lsb; /* uV */ int power_lsb; /* uW */ }; struct ina2xx_data { struct i2c_client *client; const struct ina2xx_config *config; struct mutex update_lock; bool valid; unsigned long last_updated; int kind; u16 regs[INA2XX_MAX_REGISTERS]; }; static const struct ina2xx_config ina2xx_config[] = { [ina219] = { .config_default = INA219_CONFIG_DEFAULT, .calibration_factor = 40960000, .registers = INA219_REGISTERS, .shunt_div = 100, .bus_voltage_shift = 3, .bus_voltage_lsb = 4000, .power_lsb = 20000, }, [ina226] = { .config_default = INA226_CONFIG_DEFAULT, .calibration_factor = 5120000, .registers = INA226_REGISTERS, .shunt_div = 400, .bus_voltage_shift = 0, .bus_voltage_lsb = 1250, .power_lsb = 25000, }, }; static struct ina2xx_data *ina2xx_update_device(struct device *dev) { struct ina2xx_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->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->config->registers; i++) { int rv = i2c_smbus_read_word_swapped(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 ina2xx_get_value(struct ina2xx_data *data, u8 reg) { int val; switch (reg) { case INA2XX_SHUNT_VOLTAGE: val = DIV_ROUND_CLOSEST(data->regs[reg], data->config->shunt_div); break; case INA2XX_BUS_VOLTAGE: val = (data->regs[reg] >> data->config->bus_voltage_shift) * data->config->bus_voltage_lsb; val = DIV_ROUND_CLOSEST(val, 1000); break; case INA2XX_POWER: val = data->regs[reg] * data->config->power_lsb; break; case INA2XX_CURRENT: /* LSB=1mA (selected). Is in mA */ val = data->regs[reg]; 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); if (IS_ERR(data)) return PTR_ERR(data); return snprintf(buf, PAGE_SIZE, "%d\n", ina2xx_get_value(data, attr->index)); } /* 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_attrs[] = { &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, }; ATTRIBUTE_GROUPS(ina2xx); static int ina2xx_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = client->adapter; struct ina2xx_platform_data *pdata; struct device *dev = &client->dev; struct ina2xx_data *data; struct device *hwmon_dev; long shunt = 10000; /* default shunt value 10mOhms */ u32 val; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) return -ENODEV; data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; if (dev_get_platdata(dev)) { pdata = dev_get_platdata(dev); shunt = pdata->shunt_uohms; } else if (!of_property_read_u32(dev->of_node, "shunt-resistor", &val)) { shunt = val; } if (shunt <= 0) return -ENODEV; /* set the device type */ data->kind = id->driver_data; data->config = &ina2xx_config[data->kind]; /* device configuration */ i2c_smbus_write_word_swapped(client, INA2XX_CONFIG, data->config->config_default); /* set current LSB to 1mA, shunt is in uOhms */ /* (equation 13 in datasheet) */ i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION, data->config->calibration_factor / shunt); data->client = client; mutex_init(&data->update_lock); hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, data, ina2xx_groups); if (IS_ERR(hwmon_dev)) return PTR_ERR(hwmon_dev); dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n", id->name, shunt); return 0; } static const struct i2c_device_id ina2xx_id[] = { { "ina219", ina219 }, { "ina220", ina219 }, { "ina226", ina226 }, { "ina230", ina226 }, { } }; MODULE_DEVICE_TABLE(i2c, ina2xx_id); static struct i2c_driver ina2xx_driver = { .driver = { .name = "ina2xx", }, .probe = ina2xx_probe, .id_table = ina2xx_id, }; module_i2c_driver(ina2xx_driver); MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>"); MODULE_DESCRIPTION("ina2xx driver"); MODULE_LICENSE("GPL");