2 * Driver for Texas Instruments INA219, INA226 power monitor chips
5 * Zero Drift Bi-Directional Current/Power Monitor with I2C Interface
6 * Datasheet: http://www.ti.com/product/ina219
9 * Bi-Directional Current/Power Monitor with I2C Interface
10 * Datasheet: http://www.ti.com/product/ina220
13 * Bi-Directional Current/Power Monitor with I2C Interface
14 * Datasheet: http://www.ti.com/product/ina226
17 * Bi-directional Current/Power Monitor with I2C Interface
18 * Datasheet: http://www.ti.com/product/ina230
20 * Copyright (C) 2012 Lothar Felten <l-felten@ti.com>
21 * Thanks to Jan Volkering
23 * This program is free software; you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License as published by
25 * the Free Software Foundation; version 2 of the License.
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/err.h>
32 #include <linux/slab.h>
33 #include <linux/i2c.h>
34 #include <linux/hwmon.h>
35 #include <linux/hwmon-sysfs.h>
37 #include <linux/platform_data/ina2xx.h>
39 /* common register definitions */
40 #define INA2XX_CONFIG 0x00
41 #define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */
42 #define INA2XX_BUS_VOLTAGE 0x02 /* readonly */
43 #define INA2XX_POWER 0x03 /* readonly */
44 #define INA2XX_CURRENT 0x04 /* readonly */
45 #define INA2XX_CALIBRATION 0x05
47 /* INA226 register definitions */
48 #define INA226_MASK_ENABLE 0x06
49 #define INA226_ALERT_LIMIT 0x07
50 #define INA226_DIE_ID 0xFF
54 #define INA219_REGISTERS 6
55 #define INA226_REGISTERS 8
57 #define INA2XX_MAX_REGISTERS 8
59 /* settings - depend on use case */
60 #define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
61 #define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */
63 /* worst case is 68.10 ms (~14.6Hz, ina219) */
64 #define INA2XX_CONVERSION_RATE 15
66 enum ina2xx_ids { ina219, ina226 };
68 struct ina2xx_config {
70 int calibration_factor;
73 int bus_voltage_shift;
74 int bus_voltage_lsb; /* uV */
75 int power_lsb; /* uW */
79 struct device *hwmon_dev;
80 const struct ina2xx_config *config;
82 struct mutex update_lock;
84 unsigned long last_updated;
87 u16 regs[INA2XX_MAX_REGISTERS];
90 static const struct ina2xx_config ina2xx_config[] = {
92 .config_default = INA219_CONFIG_DEFAULT,
93 .calibration_factor = 40960000,
94 .registers = INA219_REGISTERS,
96 .bus_voltage_shift = 3,
97 .bus_voltage_lsb = 4000,
101 .config_default = INA226_CONFIG_DEFAULT,
102 .calibration_factor = 5120000,
103 .registers = INA226_REGISTERS,
105 .bus_voltage_shift = 0,
106 .bus_voltage_lsb = 1250,
111 static struct ina2xx_data *ina2xx_update_device(struct device *dev)
113 struct i2c_client *client = to_i2c_client(dev);
114 struct ina2xx_data *data = i2c_get_clientdata(client);
115 struct ina2xx_data *ret = data;
117 mutex_lock(&data->update_lock);
119 if (time_after(jiffies, data->last_updated +
120 HZ / INA2XX_CONVERSION_RATE) || !data->valid) {
124 dev_dbg(&client->dev, "Starting ina2xx update\n");
126 /* Read all registers */
127 for (i = 0; i < data->config->registers; i++) {
128 int rv = i2c_smbus_read_word_swapped(client, i);
135 data->last_updated = jiffies;
139 mutex_unlock(&data->update_lock);
143 static int ina2xx_get_value(struct ina2xx_data *data, u8 reg)
148 case INA2XX_SHUNT_VOLTAGE:
149 val = DIV_ROUND_CLOSEST(data->regs[reg],
150 data->config->shunt_div);
152 case INA2XX_BUS_VOLTAGE:
153 val = (data->regs[reg] >> data->config->bus_voltage_shift)
154 * data->config->bus_voltage_lsb;
155 val = DIV_ROUND_CLOSEST(val, 1000);
158 val = data->regs[reg] * data->config->power_lsb;
161 /* LSB=1mA (selected). Is in mA */
162 val = data->regs[reg];
165 /* programmer goofed */
174 static ssize_t ina2xx_show_value(struct device *dev,
175 struct device_attribute *da, char *buf)
177 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
178 struct ina2xx_data *data = ina2xx_update_device(dev);
181 return PTR_ERR(data);
183 return snprintf(buf, PAGE_SIZE, "%d\n",
184 ina2xx_get_value(data, attr->index));
188 static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, \
189 ina2xx_show_value, NULL, INA2XX_SHUNT_VOLTAGE);
192 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, \
193 ina2xx_show_value, NULL, INA2XX_BUS_VOLTAGE);
195 /* calculated current */
196 static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, \
197 ina2xx_show_value, NULL, INA2XX_CURRENT);
199 /* calculated power */
200 static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, \
201 ina2xx_show_value, NULL, INA2XX_POWER);
203 /* pointers to created device attributes */
204 static struct attribute *ina2xx_attributes[] = {
205 &sensor_dev_attr_in0_input.dev_attr.attr,
206 &sensor_dev_attr_in1_input.dev_attr.attr,
207 &sensor_dev_attr_curr1_input.dev_attr.attr,
208 &sensor_dev_attr_power1_input.dev_attr.attr,
212 static const struct attribute_group ina2xx_group = {
213 .attrs = ina2xx_attributes,
216 static int ina2xx_probe(struct i2c_client *client,
217 const struct i2c_device_id *id)
219 struct i2c_adapter *adapter = client->adapter;
220 struct ina2xx_data *data;
221 struct ina2xx_platform_data *pdata;
223 long shunt = 10000; /* default shunt value 10mOhms */
225 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
228 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
232 if (client->dev.platform_data) {
234 (struct ina2xx_platform_data *)client->dev.platform_data;
235 shunt = pdata->shunt_uohms;
241 /* set the device type */
242 data->kind = id->driver_data;
243 data->config = &ina2xx_config[data->kind];
245 /* device configuration */
246 i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
247 data->config->config_default);
248 /* set current LSB to 1mA, shunt is in uOhms */
249 /* (equation 13 in datasheet) */
250 i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION,
251 data->config->calibration_factor / shunt);
253 i2c_set_clientdata(client, data);
254 mutex_init(&data->update_lock);
256 ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group);
260 data->hwmon_dev = hwmon_device_register(&client->dev);
261 if (IS_ERR(data->hwmon_dev)) {
262 ret = PTR_ERR(data->hwmon_dev);
266 dev_info(&client->dev, "power monitor %s (Rshunt = %li uOhm)\n",
272 sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
276 static int ina2xx_remove(struct i2c_client *client)
278 struct ina2xx_data *data = i2c_get_clientdata(client);
280 hwmon_device_unregister(data->hwmon_dev);
281 sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
286 static const struct i2c_device_id ina2xx_id[] = {
287 { "ina219", ina219 },
288 { "ina220", ina219 },
289 { "ina226", ina226 },
290 { "ina230", ina226 },
293 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
295 static struct i2c_driver ina2xx_driver = {
299 .probe = ina2xx_probe,
300 .remove = ina2xx_remove,
301 .id_table = ina2xx_id,
304 static int __init ina2xx_init(void)
306 return i2c_add_driver(&ina2xx_driver);
309 static void __exit ina2xx_exit(void)
311 i2c_del_driver(&ina2xx_driver);
314 MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
315 MODULE_DESCRIPTION("ina2xx driver");
316 MODULE_LICENSE("GPL");
318 module_init(ina2xx_init);
319 module_exit(ina2xx_exit);