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/ina226
12 * Copyright (C) 2012 Lothar Felten <l-felten@ti.com>
13 * Thanks to Jan Volkering
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; version 2 of the License.
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/err.h>
24 #include <linux/slab.h>
25 #include <linux/i2c.h>
26 #include <linux/hwmon.h>
27 #include <linux/hwmon-sysfs.h>
29 #include <linux/platform_data/ina2xx.h>
31 /* common register definitions */
32 #define INA2XX_CONFIG 0x00
33 #define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */
34 #define INA2XX_BUS_VOLTAGE 0x02 /* readonly */
35 #define INA2XX_POWER 0x03 /* readonly */
36 #define INA2XX_CURRENT 0x04 /* readonly */
37 #define INA2XX_CALIBRATION 0x05
39 /* INA226 register definitions */
40 #define INA226_MASK_ENABLE 0x06
41 #define INA226_ALERT_LIMIT 0x07
42 #define INA226_DIE_ID 0xFF
46 #define INA219_REGISTERS 6
47 #define INA226_REGISTERS 8
49 #define INA2XX_MAX_REGISTERS 8
51 /* settings - depend on use case */
52 #define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
53 #define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */
55 /* worst case is 68.10 ms (~14.6Hz, ina219) */
56 #define INA2XX_CONVERSION_RATE 15
58 enum ina2xx_ids
{ ina219
, ina226
};
61 struct device
*hwmon_dev
;
63 struct mutex update_lock
;
65 unsigned long last_updated
;
69 u16 regs
[INA2XX_MAX_REGISTERS
];
72 static struct ina2xx_data
*ina2xx_update_device(struct device
*dev
)
74 struct i2c_client
*client
= to_i2c_client(dev
);
75 struct ina2xx_data
*data
= i2c_get_clientdata(client
);
76 struct ina2xx_data
*ret
= data
;
78 mutex_lock(&data
->update_lock
);
80 if (time_after(jiffies
, data
->last_updated
+
81 HZ
/ INA2XX_CONVERSION_RATE
) || !data
->valid
) {
85 dev_dbg(&client
->dev
, "Starting ina2xx update\n");
87 /* Read all registers */
88 for (i
= 0; i
< data
->registers
; i
++) {
89 int rv
= i2c_smbus_read_word_swapped(client
, i
);
96 data
->last_updated
= jiffies
;
100 mutex_unlock(&data
->update_lock
);
104 static int ina219_get_value(struct ina2xx_data
*data
, u8 reg
)
107 * calculate exact value for the given register
108 * we assume default power-on reset settings:
109 * bus voltage range 32V
111 * adc 1 & 2 -> conversion time 532uS
112 * mode is continuous shunt and bus
113 * calibration value is INA219_CALIBRATION_VALUE
115 int val
= data
->regs
[reg
];
118 case INA2XX_SHUNT_VOLTAGE
:
119 /* LSB=10uV. Convert to mV. */
120 val
= DIV_ROUND_CLOSEST(val
, 100);
122 case INA2XX_BUS_VOLTAGE
:
123 /* LSB=4mV. Register is not right aligned, convert to mV. */
124 val
= (val
>> 3) * 4;
127 /* LSB=20mW. Convert to uW */
128 val
= val
* 20 * 1000;
131 /* LSB=1mA (selected). Is in mA */
134 /* programmer goofed */
143 static int ina226_get_value(struct ina2xx_data
*data
, u8 reg
)
146 * calculate exact value for the given register
147 * we assume default power-on reset settings:
148 * bus voltage range 32V
150 * adc 1 & 2 -> conversion time 532uS
151 * mode is continuous shunt and bus
152 * calibration value is INA226_CALIBRATION_VALUE
154 int val
= data
->regs
[reg
];
157 case INA2XX_SHUNT_VOLTAGE
:
158 /* LSB=2.5uV. Convert to mV. */
159 val
= DIV_ROUND_CLOSEST(val
, 400);
161 case INA2XX_BUS_VOLTAGE
:
162 /* LSB=1.25mV. Convert to mV. */
163 val
= val
+ DIV_ROUND_CLOSEST(val
, 4);
166 /* LSB=25mW. Convert to uW */
167 val
= val
* 25 * 1000;
170 /* LSB=1mA (selected). Is in mA */
173 /* programmer goofed */
182 static ssize_t
ina2xx_show_value(struct device
*dev
,
183 struct device_attribute
*da
, char *buf
)
185 struct sensor_device_attribute
*attr
= to_sensor_dev_attr(da
);
186 struct ina2xx_data
*data
= ina2xx_update_device(dev
);
190 return PTR_ERR(data
);
192 switch (data
->kind
) {
194 value
= ina219_get_value(data
, attr
->index
);
197 value
= ina226_get_value(data
, attr
->index
);
203 return snprintf(buf
, PAGE_SIZE
, "%d\n", value
);
207 static SENSOR_DEVICE_ATTR(in0_input
, S_IRUGO
, \
208 ina2xx_show_value
, NULL
, INA2XX_SHUNT_VOLTAGE
);
211 static SENSOR_DEVICE_ATTR(in1_input
, S_IRUGO
, \
212 ina2xx_show_value
, NULL
, INA2XX_BUS_VOLTAGE
);
214 /* calculated current */
215 static SENSOR_DEVICE_ATTR(curr1_input
, S_IRUGO
, \
216 ina2xx_show_value
, NULL
, INA2XX_CURRENT
);
218 /* calculated power */
219 static SENSOR_DEVICE_ATTR(power1_input
, S_IRUGO
, \
220 ina2xx_show_value
, NULL
, INA2XX_POWER
);
222 /* pointers to created device attributes */
223 static struct attribute
*ina2xx_attributes
[] = {
224 &sensor_dev_attr_in0_input
.dev_attr
.attr
,
225 &sensor_dev_attr_in1_input
.dev_attr
.attr
,
226 &sensor_dev_attr_curr1_input
.dev_attr
.attr
,
227 &sensor_dev_attr_power1_input
.dev_attr
.attr
,
231 static const struct attribute_group ina2xx_group
= {
232 .attrs
= ina2xx_attributes
,
235 static int ina2xx_probe(struct i2c_client
*client
,
236 const struct i2c_device_id
*id
)
238 struct i2c_adapter
*adapter
= client
->adapter
;
239 struct ina2xx_data
*data
;
240 struct ina2xx_platform_data
*pdata
;
242 long shunt
= 10000; /* default shunt value 10mOhms */
244 if (!i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_WORD_DATA
))
247 data
= devm_kzalloc(&client
->dev
, sizeof(*data
), GFP_KERNEL
);
251 if (client
->dev
.platform_data
) {
253 (struct ina2xx_platform_data
*)client
->dev
.platform_data
;
254 shunt
= pdata
->shunt_uohms
;
260 /* set the device type */
261 data
->kind
= id
->driver_data
;
263 switch (data
->kind
) {
265 /* device configuration */
266 i2c_smbus_write_word_swapped(client
, INA2XX_CONFIG
,
267 INA219_CONFIG_DEFAULT
);
269 /* set current LSB to 1mA, shunt is in uOhms */
270 /* (equation 13 in datasheet) */
271 i2c_smbus_write_word_swapped(client
, INA2XX_CALIBRATION
,
273 dev_info(&client
->dev
,
274 "power monitor INA219 (Rshunt = %li uOhm)\n", shunt
);
275 data
->registers
= INA219_REGISTERS
;
278 /* device configuration */
279 i2c_smbus_write_word_swapped(client
, INA2XX_CONFIG
,
280 INA226_CONFIG_DEFAULT
);
282 /* set current LSB to 1mA, shunt is in uOhms */
283 /* (equation 1 in datasheet)*/
284 i2c_smbus_write_word_swapped(client
, INA2XX_CALIBRATION
,
286 dev_info(&client
->dev
,
287 "power monitor INA226 (Rshunt = %li uOhm)\n", shunt
);
288 data
->registers
= INA226_REGISTERS
;
291 /* unknown device id */
295 i2c_set_clientdata(client
, data
);
296 mutex_init(&data
->update_lock
);
298 ret
= sysfs_create_group(&client
->dev
.kobj
, &ina2xx_group
);
302 data
->hwmon_dev
= hwmon_device_register(&client
->dev
);
303 if (IS_ERR(data
->hwmon_dev
)) {
304 ret
= PTR_ERR(data
->hwmon_dev
);
311 sysfs_remove_group(&client
->dev
.kobj
, &ina2xx_group
);
315 static int ina2xx_remove(struct i2c_client
*client
)
317 struct ina2xx_data
*data
= i2c_get_clientdata(client
);
319 hwmon_device_unregister(data
->hwmon_dev
);
320 sysfs_remove_group(&client
->dev
.kobj
, &ina2xx_group
);
325 static const struct i2c_device_id ina2xx_id
[] = {
326 { "ina219", ina219
},
327 { "ina226", ina226
},
330 MODULE_DEVICE_TABLE(i2c
, ina2xx_id
);
332 static struct i2c_driver ina2xx_driver
= {
336 .probe
= ina2xx_probe
,
337 .remove
= ina2xx_remove
,
338 .id_table
= ina2xx_id
,
341 static int __init
ina2xx_init(void)
343 return i2c_add_driver(&ina2xx_driver
);
346 static void __exit
ina2xx_exit(void)
348 i2c_del_driver(&ina2xx_driver
);
351 MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
352 MODULE_DESCRIPTION("ina2xx driver");
353 MODULE_LICENSE("GPL");
355 module_init(ina2xx_init
);
356 module_exit(ina2xx_exit
);