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Felten, Lotharf7c2fe32012-05-12 04:36:38 -04001/*
2 * Driver for Texas Instruments INA219, INA226 power monitor chips
3 *
4 * INA219:
5 * Zero Drift Bi-Directional Current/Power Monitor with I2C Interface
6 * Datasheet: http://www.ti.com/product/ina219
7 *
Guenter Roeckdc92cd02012-05-12 11:33:11 -07008 * INA220:
9 * Bi-Directional Current/Power Monitor with I2C Interface
10 * Datasheet: http://www.ti.com/product/ina220
11 *
Felten, Lotharf7c2fe32012-05-12 04:36:38 -040012 * INA226:
13 * Bi-Directional Current/Power Monitor with I2C Interface
14 * Datasheet: http://www.ti.com/product/ina226
15 *
Guenter Roeckdc92cd02012-05-12 11:33:11 -070016 * INA230:
17 * Bi-directional Current/Power Monitor with I2C Interface
18 * Datasheet: http://www.ti.com/product/ina230
19 *
Felten, Lotharf7c2fe32012-05-12 04:36:38 -040020 * Copyright (C) 2012 Lothar Felten <l-felten@ti.com>
21 * Thanks to Jan Volkering
22 *
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.
26 */
27
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>
Jean Delvaredcd8f392012-10-10 15:25:56 +020036#include <linux/jiffies.h>
Felten, Lotharf7c2fe32012-05-12 04:36:38 -040037
38#include <linux/platform_data/ina2xx.h>
39
40/* common register definitions */
41#define INA2XX_CONFIG 0x00
42#define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */
43#define INA2XX_BUS_VOLTAGE 0x02 /* readonly */
44#define INA2XX_POWER 0x03 /* readonly */
45#define INA2XX_CURRENT 0x04 /* readonly */
46#define INA2XX_CALIBRATION 0x05
47
48/* INA226 register definitions */
49#define INA226_MASK_ENABLE 0x06
50#define INA226_ALERT_LIMIT 0x07
51#define INA226_DIE_ID 0xFF
52
53
54/* register count */
55#define INA219_REGISTERS 6
56#define INA226_REGISTERS 8
57
58#define INA2XX_MAX_REGISTERS 8
59
60/* settings - depend on use case */
61#define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
62#define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */
63
64/* worst case is 68.10 ms (~14.6Hz, ina219) */
65#define INA2XX_CONVERSION_RATE 15
66
67enum ina2xx_ids { ina219, ina226 };
68
Guenter Roeck6106db22012-05-12 11:21:01 -070069struct ina2xx_config {
70 u16 config_default;
71 int calibration_factor;
72 int registers;
73 int shunt_div;
74 int bus_voltage_shift;
75 int bus_voltage_lsb; /* uV */
76 int power_lsb; /* uW */
77};
78
Felten, Lotharf7c2fe32012-05-12 04:36:38 -040079struct ina2xx_data {
80 struct device *hwmon_dev;
Guenter Roeck6106db22012-05-12 11:21:01 -070081 const struct ina2xx_config *config;
Felten, Lotharf7c2fe32012-05-12 04:36:38 -040082
83 struct mutex update_lock;
84 bool valid;
85 unsigned long last_updated;
86
87 int kind;
Felten, Lotharf7c2fe32012-05-12 04:36:38 -040088 u16 regs[INA2XX_MAX_REGISTERS];
89};
90
Guenter Roeck6106db22012-05-12 11:21:01 -070091static const struct ina2xx_config ina2xx_config[] = {
92 [ina219] = {
93 .config_default = INA219_CONFIG_DEFAULT,
94 .calibration_factor = 40960000,
95 .registers = INA219_REGISTERS,
96 .shunt_div = 100,
97 .bus_voltage_shift = 3,
98 .bus_voltage_lsb = 4000,
99 .power_lsb = 20000,
100 },
101 [ina226] = {
102 .config_default = INA226_CONFIG_DEFAULT,
103 .calibration_factor = 5120000,
104 .registers = INA226_REGISTERS,
105 .shunt_div = 400,
106 .bus_voltage_shift = 0,
107 .bus_voltage_lsb = 1250,
108 .power_lsb = 25000,
109 },
110};
111
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400112static struct ina2xx_data *ina2xx_update_device(struct device *dev)
113{
114 struct i2c_client *client = to_i2c_client(dev);
115 struct ina2xx_data *data = i2c_get_clientdata(client);
116 struct ina2xx_data *ret = data;
117
118 mutex_lock(&data->update_lock);
119
120 if (time_after(jiffies, data->last_updated +
121 HZ / INA2XX_CONVERSION_RATE) || !data->valid) {
122
123 int i;
124
125 dev_dbg(&client->dev, "Starting ina2xx update\n");
126
127 /* Read all registers */
Guenter Roeck6106db22012-05-12 11:21:01 -0700128 for (i = 0; i < data->config->registers; i++) {
Guenter Roeck080b98e2012-09-11 08:22:14 -0700129 int rv = i2c_smbus_read_word_swapped(client, i);
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400130 if (rv < 0) {
131 ret = ERR_PTR(rv);
132 goto abort;
133 }
134 data->regs[i] = rv;
135 }
136 data->last_updated = jiffies;
137 data->valid = 1;
138 }
139abort:
140 mutex_unlock(&data->update_lock);
141 return ret;
142}
143
Guenter Roeck6106db22012-05-12 11:21:01 -0700144static int ina2xx_get_value(struct ina2xx_data *data, u8 reg)
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400145{
Guenter Roeck6106db22012-05-12 11:21:01 -0700146 int val;
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400147
148 switch (reg) {
149 case INA2XX_SHUNT_VOLTAGE:
Guenter Roeck6106db22012-05-12 11:21:01 -0700150 val = DIV_ROUND_CLOSEST(data->regs[reg],
151 data->config->shunt_div);
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400152 break;
153 case INA2XX_BUS_VOLTAGE:
Guenter Roeck6106db22012-05-12 11:21:01 -0700154 val = (data->regs[reg] >> data->config->bus_voltage_shift)
155 * data->config->bus_voltage_lsb;
156 val = DIV_ROUND_CLOSEST(val, 1000);
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400157 break;
158 case INA2XX_POWER:
Guenter Roeck6106db22012-05-12 11:21:01 -0700159 val = data->regs[reg] * data->config->power_lsb;
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400160 break;
161 case INA2XX_CURRENT:
162 /* LSB=1mA (selected). Is in mA */
Guenter Roeck6106db22012-05-12 11:21:01 -0700163 val = data->regs[reg];
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400164 break;
165 default:
166 /* programmer goofed */
167 WARN_ON_ONCE(1);
168 val = 0;
169 break;
170 }
171
172 return val;
173}
174
175static ssize_t ina2xx_show_value(struct device *dev,
176 struct device_attribute *da, char *buf)
177{
178 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
179 struct ina2xx_data *data = ina2xx_update_device(dev);
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400180
181 if (IS_ERR(data))
182 return PTR_ERR(data);
183
Guenter Roeck6106db22012-05-12 11:21:01 -0700184 return snprintf(buf, PAGE_SIZE, "%d\n",
185 ina2xx_get_value(data, attr->index));
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400186}
187
188/* shunt voltage */
Guenter Roeckf0df0fd2013-01-10 10:04:06 -0800189static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
190 INA2XX_SHUNT_VOLTAGE);
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400191
192/* bus voltage */
Guenter Roeckf0df0fd2013-01-10 10:04:06 -0800193static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina2xx_show_value, NULL,
194 INA2XX_BUS_VOLTAGE);
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400195
196/* calculated current */
Guenter Roeckf0df0fd2013-01-10 10:04:06 -0800197static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina2xx_show_value, NULL,
198 INA2XX_CURRENT);
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400199
200/* calculated power */
Guenter Roeckf0df0fd2013-01-10 10:04:06 -0800201static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina2xx_show_value, NULL,
202 INA2XX_POWER);
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400203
204/* pointers to created device attributes */
205static struct attribute *ina2xx_attributes[] = {
206 &sensor_dev_attr_in0_input.dev_attr.attr,
207 &sensor_dev_attr_in1_input.dev_attr.attr,
208 &sensor_dev_attr_curr1_input.dev_attr.attr,
209 &sensor_dev_attr_power1_input.dev_attr.attr,
210 NULL,
211};
212
213static const struct attribute_group ina2xx_group = {
214 .attrs = ina2xx_attributes,
215};
216
217static int ina2xx_probe(struct i2c_client *client,
218 const struct i2c_device_id *id)
219{
220 struct i2c_adapter *adapter = client->adapter;
221 struct ina2xx_data *data;
222 struct ina2xx_platform_data *pdata;
Guenter Roeck6106db22012-05-12 11:21:01 -0700223 int ret;
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400224 long shunt = 10000; /* default shunt value 10mOhms */
225
226 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
227 return -ENODEV;
228
229 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
230 if (!data)
231 return -ENOMEM;
232
233 if (client->dev.platform_data) {
234 pdata =
235 (struct ina2xx_platform_data *)client->dev.platform_data;
236 shunt = pdata->shunt_uohms;
237 }
238
239 if (shunt <= 0)
240 return -ENODEV;
241
242 /* set the device type */
243 data->kind = id->driver_data;
Guenter Roeck6106db22012-05-12 11:21:01 -0700244 data->config = &ina2xx_config[data->kind];
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400245
Guenter Roeck6106db22012-05-12 11:21:01 -0700246 /* device configuration */
247 i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
248 data->config->config_default);
249 /* set current LSB to 1mA, shunt is in uOhms */
250 /* (equation 13 in datasheet) */
251 i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION,
252 data->config->calibration_factor / shunt);
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400253
254 i2c_set_clientdata(client, data);
255 mutex_init(&data->update_lock);
256
257 ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group);
258 if (ret)
259 return ret;
260
261 data->hwmon_dev = hwmon_device_register(&client->dev);
262 if (IS_ERR(data->hwmon_dev)) {
263 ret = PTR_ERR(data->hwmon_dev);
264 goto out_err_hwmon;
265 }
266
Guenter Roeck6106db22012-05-12 11:21:01 -0700267 dev_info(&client->dev, "power monitor %s (Rshunt = %li uOhm)\n",
268 id->name, shunt);
269
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400270 return 0;
271
272out_err_hwmon:
273 sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
274 return ret;
275}
276
277static int ina2xx_remove(struct i2c_client *client)
278{
279 struct ina2xx_data *data = i2c_get_clientdata(client);
280
281 hwmon_device_unregister(data->hwmon_dev);
282 sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
283
284 return 0;
285}
286
287static const struct i2c_device_id ina2xx_id[] = {
288 { "ina219", ina219 },
Guenter Roeckdc92cd02012-05-12 11:33:11 -0700289 { "ina220", ina219 },
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400290 { "ina226", ina226 },
Guenter Roeckdc92cd02012-05-12 11:33:11 -0700291 { "ina230", ina226 },
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400292 { }
293};
294MODULE_DEVICE_TABLE(i2c, ina2xx_id);
295
296static struct i2c_driver ina2xx_driver = {
297 .driver = {
298 .name = "ina2xx",
299 },
300 .probe = ina2xx_probe,
301 .remove = ina2xx_remove,
302 .id_table = ina2xx_id,
303};
304
Wei Yongjund835ca02012-10-08 20:40:35 +0800305module_i2c_driver(ina2xx_driver);
Felten, Lotharf7c2fe32012-05-12 04:36:38 -0400306
307MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
308MODULE_DESCRIPTION("ina2xx driver");
309MODULE_LICENSE("GPL");