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>
36 #include <linux/jiffies.h>
38 #include <linux/delay.h>
40 #include <linux/platform_data/ina2xx.h>
42 /* common register definitions */
43 #define INA2XX_CONFIG 0x00
44 #define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */
45 #define INA2XX_BUS_VOLTAGE 0x02 /* readonly */
46 #define INA2XX_POWER 0x03 /* readonly */
47 #define INA2XX_CURRENT 0x04 /* readonly */
48 #define INA2XX_CALIBRATION 0x05
50 /* INA226 register definitions */
51 #define INA226_MASK_ENABLE 0x06
52 #define INA226_ALERT_LIMIT 0x07
53 #define INA226_DIE_ID 0xFF
56 #define INA219_REGISTERS 6
57 #define INA226_REGISTERS 8
59 #define INA2XX_MAX_REGISTERS 8
61 /* settings - depend on use case */
62 #define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
63 #define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */
65 /* worst case is 68.10 ms (~14.6Hz, ina219) */
66 #define INA2XX_CONVERSION_RATE 15
67 #define INA2XX_MAX_DELAY 69 /* worst case delay in ms */
69 #define INA2XX_RSHUNT_DEFAULT 10000
71 /* bit mask for reading the averaging setting in the configuration register */
72 #define INA226_AVG_RD_MASK 0x0E00
74 #define INA226_READ_AVG(reg) (((reg) & INA226_AVG_RD_MASK) >> 9)
75 #define INA226_SHIFT_AVG(val) ((val) << 9)
77 /* common attrs, ina226 attrs and NULL */
78 #define INA2XX_MAX_ATTRIBUTE_GROUPS 3
81 * Both bus voltage and shunt voltage conversion times for ina226 are set
82 * to 0b0100 on POR, which translates to 2200 microseconds in total.
84 #define INA226_TOTAL_CONV_TIME_DEFAULT 2200
86 enum ina2xx_ids { ina219, ina226 };
88 struct ina2xx_config {
90 int calibration_factor;
93 int bus_voltage_shift;
94 int bus_voltage_lsb; /* uV */
95 int power_lsb; /* uW */
99 struct i2c_client *client;
100 const struct ina2xx_config *config;
105 struct mutex update_lock;
107 unsigned long last_updated;
108 int update_interval; /* in jiffies */
111 const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
112 u16 regs[INA2XX_MAX_REGISTERS];
115 static const struct ina2xx_config ina2xx_config[] = {
117 .config_default = INA219_CONFIG_DEFAULT,
118 .calibration_factor = 40960000,
119 .registers = INA219_REGISTERS,
121 .bus_voltage_shift = 3,
122 .bus_voltage_lsb = 4000,
126 .config_default = INA226_CONFIG_DEFAULT,
127 .calibration_factor = 5120000,
128 .registers = INA226_REGISTERS,
130 .bus_voltage_shift = 0,
131 .bus_voltage_lsb = 1250,
137 * Available averaging rates for ina226. The indices correspond with
138 * the bit values expected by the chip (according to the ina226 datasheet,
139 * table 3 AVG bit settings, found at
140 * http://www.ti.com/lit/ds/symlink/ina226.pdf.
142 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
144 static int ina226_avg_bits(int avg)
148 /* Get the closest average from the tab. */
149 for (i = 0; i < ARRAY_SIZE(ina226_avg_tab) - 1; i++) {
150 if (avg <= (ina226_avg_tab[i] + ina226_avg_tab[i + 1]) / 2)
154 return i; /* Return 0b0111 for values greater than 1024. */
157 static int ina226_reg_to_interval(u16 config)
159 int avg = ina226_avg_tab[INA226_READ_AVG(config)];
162 * Multiply the total conversion time by the number of averages.
163 * Return the result in milliseconds.
165 return DIV_ROUND_CLOSEST(avg * INA226_TOTAL_CONV_TIME_DEFAULT, 1000);
168 static u16 ina226_interval_to_reg(int interval, u16 config)
172 avg = DIV_ROUND_CLOSEST(interval * 1000,
173 INA226_TOTAL_CONV_TIME_DEFAULT);
174 avg_bits = ina226_avg_bits(avg);
176 return (config & ~INA226_AVG_RD_MASK) | INA226_SHIFT_AVG(avg_bits);
179 static void ina226_set_update_interval(struct ina2xx_data *data)
183 ms = ina226_reg_to_interval(data->curr_config);
184 data->update_interval = msecs_to_jiffies(ms);
187 static int ina2xx_calibrate(struct ina2xx_data *data)
189 return i2c_smbus_write_word_swapped(data->client, INA2XX_CALIBRATION,
190 data->config->calibration_factor / data->rshunt);
194 * Initialize the configuration and calibration registers.
196 static int ina2xx_init(struct ina2xx_data *data)
198 struct i2c_client *client = data->client;
201 /* device configuration */
202 ret = i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
208 * Set current LSB to 1mA, shunt is in uOhms
209 * (equation 13 in datasheet).
211 return ina2xx_calibrate(data);
214 static int ina2xx_do_update(struct device *dev)
216 struct ina2xx_data *data = dev_get_drvdata(dev);
217 struct i2c_client *client = data->client;
220 dev_dbg(&client->dev, "Starting ina2xx update\n");
222 for (retry = 5; retry; retry--) {
223 /* Read all registers */
224 for (i = 0; i < data->config->registers; i++) {
225 rv = i2c_smbus_read_word_swapped(client, i);
232 * If the current value in the calibration register is 0, the
233 * power and current registers will also remain at 0. In case
234 * the chip has been reset let's check the calibration
235 * register and reinitialize if needed.
237 if (data->regs[INA2XX_CALIBRATION] == 0) {
238 dev_warn(dev, "chip not calibrated, reinitializing\n");
240 rv = ina2xx_init(data);
245 * Let's make sure the power and current registers
246 * have been updated before trying again.
248 msleep(INA2XX_MAX_DELAY);
252 data->last_updated = jiffies;
259 * If we're here then although all write operations succeeded, the
260 * chip still returns 0 in the calibration register. Nothing more we
263 dev_err(dev, "unable to reinitialize the chip\n");
267 static struct ina2xx_data *ina2xx_update_device(struct device *dev)
269 struct ina2xx_data *data = dev_get_drvdata(dev);
270 struct ina2xx_data *ret = data;
274 mutex_lock(&data->update_lock);
276 after = data->last_updated + data->update_interval;
277 if (time_after(jiffies, after) || !data->valid) {
278 rv = ina2xx_do_update(dev);
283 mutex_unlock(&data->update_lock);
287 static int ina2xx_get_value(struct ina2xx_data *data, u8 reg)
292 case INA2XX_SHUNT_VOLTAGE:
293 /* signed register */
294 val = DIV_ROUND_CLOSEST((s16)data->regs[reg],
295 data->config->shunt_div);
297 case INA2XX_BUS_VOLTAGE:
298 val = (data->regs[reg] >> data->config->bus_voltage_shift)
299 * data->config->bus_voltage_lsb;
300 val = DIV_ROUND_CLOSEST(val, 1000);
303 val = data->regs[reg] * data->config->power_lsb;
306 /* signed register, LSB=1mA (selected), in mA */
307 val = (s16)data->regs[reg];
309 case INA2XX_CALIBRATION:
310 val = data->config->calibration_factor / data->regs[reg];
313 /* programmer goofed */
322 static ssize_t ina2xx_show_value(struct device *dev,
323 struct device_attribute *da, char *buf)
325 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
326 struct ina2xx_data *data = ina2xx_update_device(dev);
329 return PTR_ERR(data);
331 return snprintf(buf, PAGE_SIZE, "%d\n",
332 ina2xx_get_value(data, attr->index));
335 static ssize_t ina2xx_set_shunt(struct device *dev,
336 struct device_attribute *da,
337 const char *buf, size_t count)
339 struct ina2xx_data *data = ina2xx_update_device(dev);
344 return PTR_ERR(data);
346 status = kstrtoul(buf, 10, &val);
351 /* Values greater than the calibration factor make no sense. */
352 val > data->config->calibration_factor)
355 mutex_lock(&data->update_lock);
357 status = ina2xx_calibrate(data);
358 mutex_unlock(&data->update_lock);
365 static ssize_t ina226_set_interval(struct device *dev,
366 struct device_attribute *da,
367 const char *buf, size_t count)
369 struct ina2xx_data *data = dev_get_drvdata(dev);
374 return PTR_ERR(data);
376 status = kstrtoul(buf, 10, &val);
380 if (val > INT_MAX || val == 0)
383 mutex_lock(&data->update_lock);
384 data->curr_config = ina226_interval_to_reg(val,
385 data->regs[INA2XX_CONFIG]);
386 status = i2c_smbus_write_word_swapped(data->client,
390 ina226_set_update_interval(data);
391 /* Make sure the next access re-reads all registers. */
393 mutex_unlock(&data->update_lock);
400 static ssize_t ina226_show_interval(struct device *dev,
401 struct device_attribute *da, char *buf)
403 struct ina2xx_data *data = ina2xx_update_device(dev);
406 return PTR_ERR(data);
409 * We don't use data->update_interval here as we want to display
410 * the actual interval used by the chip and jiffies_to_msecs()
411 * doesn't seem to be accurate enough.
413 return snprintf(buf, PAGE_SIZE, "%d\n",
414 ina226_reg_to_interval(data->regs[INA2XX_CONFIG]));
418 static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
419 INA2XX_SHUNT_VOLTAGE);
422 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina2xx_show_value, NULL,
425 /* calculated current */
426 static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina2xx_show_value, NULL,
429 /* calculated power */
430 static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina2xx_show_value, NULL,
433 /* shunt resistance */
434 static SENSOR_DEVICE_ATTR(shunt_resistor, S_IRUGO | S_IWUSR,
435 ina2xx_show_value, ina2xx_set_shunt,
438 /* update interval (ina226 only) */
439 static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR,
440 ina226_show_interval, ina226_set_interval, 0);
442 /* pointers to created device attributes */
443 static struct attribute *ina2xx_attrs[] = {
444 &sensor_dev_attr_in0_input.dev_attr.attr,
445 &sensor_dev_attr_in1_input.dev_attr.attr,
446 &sensor_dev_attr_curr1_input.dev_attr.attr,
447 &sensor_dev_attr_power1_input.dev_attr.attr,
448 &sensor_dev_attr_shunt_resistor.dev_attr.attr,
452 static const struct attribute_group ina2xx_group = {
453 .attrs = ina2xx_attrs,
456 static struct attribute *ina226_attrs[] = {
457 &sensor_dev_attr_update_interval.dev_attr.attr,
461 static const struct attribute_group ina226_group = {
462 .attrs = ina226_attrs,
465 static int ina2xx_probe(struct i2c_client *client,
466 const struct i2c_device_id *id)
468 struct i2c_adapter *adapter = client->adapter;
469 struct ina2xx_platform_data *pdata;
470 struct device *dev = &client->dev;
471 struct ina2xx_data *data;
472 struct device *hwmon_dev;
476 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
479 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
483 if (dev_get_platdata(dev)) {
484 pdata = dev_get_platdata(dev);
485 data->rshunt = pdata->shunt_uohms;
486 } else if (!of_property_read_u32(dev->of_node,
487 "shunt-resistor", &val)) {
490 data->rshunt = INA2XX_RSHUNT_DEFAULT;
493 /* set the device type */
494 data->kind = id->driver_data;
495 data->config = &ina2xx_config[data->kind];
496 data->curr_config = data->config->config_default;
497 data->client = client;
500 * Ina226 has a variable update_interval. For ina219 we
501 * use a constant value.
503 if (data->kind == ina226)
504 ina226_set_update_interval(data);
506 data->update_interval = HZ / INA2XX_CONVERSION_RATE;
508 if (data->rshunt <= 0 ||
509 data->rshunt > data->config->calibration_factor)
512 ret = ina2xx_init(data);
514 dev_err(dev, "error configuring the device: %d\n", ret);
518 mutex_init(&data->update_lock);
520 data->groups[group++] = &ina2xx_group;
521 if (data->kind == ina226)
522 data->groups[group++] = &ina226_group;
524 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
526 if (IS_ERR(hwmon_dev))
527 return PTR_ERR(hwmon_dev);
529 dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n",
530 id->name, data->rshunt);
535 static const struct i2c_device_id ina2xx_id[] = {
536 { "ina219", ina219 },
537 { "ina220", ina219 },
538 { "ina226", ina226 },
539 { "ina230", ina226 },
542 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
544 static struct i2c_driver ina2xx_driver = {
548 .probe = ina2xx_probe,
549 .id_table = ina2xx_id,
552 module_i2c_driver(ina2xx_driver);
554 MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
555 MODULE_DESCRIPTION("ina2xx driver");
556 MODULE_LICENSE("GPL");