Felten, Lothar | f7c2fe3 | 2012-05-12 04:36:38 -0400 | [diff] [blame] | 1 | /* |
| 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 | * |
| 8 | * INA226: |
| 9 | * Bi-Directional Current/Power Monitor with I2C Interface |
| 10 | * Datasheet: http://www.ti.com/product/ina226 |
| 11 | * |
| 12 | * Copyright (C) 2012 Lothar Felten <l-felten@ti.com> |
| 13 | * Thanks to Jan Volkering |
| 14 | * |
| 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. |
| 18 | */ |
| 19 | |
| 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> |
| 28 | |
| 29 | #include <linux/platform_data/ina2xx.h> |
| 30 | |
| 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 |
| 38 | |
| 39 | /* INA226 register definitions */ |
| 40 | #define INA226_MASK_ENABLE 0x06 |
| 41 | #define INA226_ALERT_LIMIT 0x07 |
| 42 | #define INA226_DIE_ID 0xFF |
| 43 | |
| 44 | |
| 45 | /* register count */ |
| 46 | #define INA219_REGISTERS 6 |
| 47 | #define INA226_REGISTERS 8 |
| 48 | |
| 49 | #define INA2XX_MAX_REGISTERS 8 |
| 50 | |
| 51 | /* settings - depend on use case */ |
| 52 | #define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */ |
| 53 | #define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */ |
| 54 | |
| 55 | /* worst case is 68.10 ms (~14.6Hz, ina219) */ |
| 56 | #define INA2XX_CONVERSION_RATE 15 |
| 57 | |
| 58 | enum ina2xx_ids { ina219, ina226 }; |
| 59 | |
| 60 | struct ina2xx_data { |
| 61 | struct device *hwmon_dev; |
| 62 | |
| 63 | struct mutex update_lock; |
| 64 | bool valid; |
| 65 | unsigned long last_updated; |
| 66 | |
| 67 | int kind; |
| 68 | int registers; |
| 69 | u16 regs[INA2XX_MAX_REGISTERS]; |
| 70 | }; |
| 71 | |
Felten, Lothar | f7c2fe3 | 2012-05-12 04:36:38 -0400 | [diff] [blame] | 72 | static struct ina2xx_data *ina2xx_update_device(struct device *dev) |
| 73 | { |
| 74 | struct i2c_client *client = to_i2c_client(dev); |
| 75 | struct ina2xx_data *data = i2c_get_clientdata(client); |
| 76 | struct ina2xx_data *ret = data; |
| 77 | |
| 78 | mutex_lock(&data->update_lock); |
| 79 | |
| 80 | if (time_after(jiffies, data->last_updated + |
| 81 | HZ / INA2XX_CONVERSION_RATE) || !data->valid) { |
| 82 | |
| 83 | int i; |
| 84 | |
| 85 | dev_dbg(&client->dev, "Starting ina2xx update\n"); |
| 86 | |
| 87 | /* Read all registers */ |
| 88 | for (i = 0; i < data->registers; i++) { |
Guenter Roeck | 080b98e | 2012-09-11 08:22:14 -0700 | [diff] [blame^] | 89 | int rv = i2c_smbus_read_word_swapped(client, i); |
Felten, Lothar | f7c2fe3 | 2012-05-12 04:36:38 -0400 | [diff] [blame] | 90 | if (rv < 0) { |
| 91 | ret = ERR_PTR(rv); |
| 92 | goto abort; |
| 93 | } |
| 94 | data->regs[i] = rv; |
| 95 | } |
| 96 | data->last_updated = jiffies; |
| 97 | data->valid = 1; |
| 98 | } |
| 99 | abort: |
| 100 | mutex_unlock(&data->update_lock); |
| 101 | return ret; |
| 102 | } |
| 103 | |
| 104 | static int ina219_get_value(struct ina2xx_data *data, u8 reg) |
| 105 | { |
| 106 | /* |
| 107 | * calculate exact value for the given register |
| 108 | * we assume default power-on reset settings: |
| 109 | * bus voltage range 32V |
| 110 | * gain = /8 |
| 111 | * adc 1 & 2 -> conversion time 532uS |
| 112 | * mode is continuous shunt and bus |
| 113 | * calibration value is INA219_CALIBRATION_VALUE |
| 114 | */ |
| 115 | int val = data->regs[reg]; |
| 116 | |
| 117 | switch (reg) { |
| 118 | case INA2XX_SHUNT_VOLTAGE: |
| 119 | /* LSB=10uV. Convert to mV. */ |
| 120 | val = DIV_ROUND_CLOSEST(val, 100); |
| 121 | break; |
| 122 | case INA2XX_BUS_VOLTAGE: |
| 123 | /* LSB=4mV. Register is not right aligned, convert to mV. */ |
| 124 | val = (val >> 3) * 4; |
| 125 | break; |
| 126 | case INA2XX_POWER: |
| 127 | /* LSB=20mW. Convert to uW */ |
| 128 | val = val * 20 * 1000; |
| 129 | break; |
| 130 | case INA2XX_CURRENT: |
| 131 | /* LSB=1mA (selected). Is in mA */ |
| 132 | break; |
| 133 | default: |
| 134 | /* programmer goofed */ |
| 135 | WARN_ON_ONCE(1); |
| 136 | val = 0; |
| 137 | break; |
| 138 | } |
| 139 | |
| 140 | return val; |
| 141 | } |
| 142 | |
| 143 | static int ina226_get_value(struct ina2xx_data *data, u8 reg) |
| 144 | { |
| 145 | /* |
| 146 | * calculate exact value for the given register |
| 147 | * we assume default power-on reset settings: |
| 148 | * bus voltage range 32V |
| 149 | * gain = /8 |
| 150 | * adc 1 & 2 -> conversion time 532uS |
| 151 | * mode is continuous shunt and bus |
| 152 | * calibration value is INA226_CALIBRATION_VALUE |
| 153 | */ |
| 154 | int val = data->regs[reg]; |
| 155 | |
| 156 | switch (reg) { |
| 157 | case INA2XX_SHUNT_VOLTAGE: |
| 158 | /* LSB=2.5uV. Convert to mV. */ |
| 159 | val = DIV_ROUND_CLOSEST(val, 400); |
| 160 | break; |
| 161 | case INA2XX_BUS_VOLTAGE: |
| 162 | /* LSB=1.25mV. Convert to mV. */ |
| 163 | val = val + DIV_ROUND_CLOSEST(val, 4); |
| 164 | break; |
| 165 | case INA2XX_POWER: |
| 166 | /* LSB=25mW. Convert to uW */ |
| 167 | val = val * 25 * 1000; |
| 168 | break; |
| 169 | case INA2XX_CURRENT: |
| 170 | /* LSB=1mA (selected). Is in mA */ |
| 171 | break; |
| 172 | default: |
| 173 | /* programmer goofed */ |
| 174 | WARN_ON_ONCE(1); |
| 175 | val = 0; |
| 176 | break; |
| 177 | } |
| 178 | |
| 179 | return val; |
| 180 | } |
| 181 | |
| 182 | static ssize_t ina2xx_show_value(struct device *dev, |
| 183 | struct device_attribute *da, char *buf) |
| 184 | { |
| 185 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); |
| 186 | struct ina2xx_data *data = ina2xx_update_device(dev); |
| 187 | int value = 0; |
| 188 | |
| 189 | if (IS_ERR(data)) |
| 190 | return PTR_ERR(data); |
| 191 | |
| 192 | switch (data->kind) { |
| 193 | case ina219: |
| 194 | value = ina219_get_value(data, attr->index); |
| 195 | break; |
| 196 | case ina226: |
| 197 | value = ina226_get_value(data, attr->index); |
| 198 | break; |
| 199 | default: |
| 200 | WARN_ON_ONCE(1); |
| 201 | break; |
| 202 | } |
| 203 | return snprintf(buf, PAGE_SIZE, "%d\n", value); |
| 204 | } |
| 205 | |
| 206 | /* shunt voltage */ |
| 207 | static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, \ |
| 208 | ina2xx_show_value, NULL, INA2XX_SHUNT_VOLTAGE); |
| 209 | |
| 210 | /* bus voltage */ |
| 211 | static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, \ |
| 212 | ina2xx_show_value, NULL, INA2XX_BUS_VOLTAGE); |
| 213 | |
| 214 | /* calculated current */ |
| 215 | static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, \ |
| 216 | ina2xx_show_value, NULL, INA2XX_CURRENT); |
| 217 | |
| 218 | /* calculated power */ |
| 219 | static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, \ |
| 220 | ina2xx_show_value, NULL, INA2XX_POWER); |
| 221 | |
| 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, |
| 228 | NULL, |
| 229 | }; |
| 230 | |
| 231 | static const struct attribute_group ina2xx_group = { |
| 232 | .attrs = ina2xx_attributes, |
| 233 | }; |
| 234 | |
| 235 | static int ina2xx_probe(struct i2c_client *client, |
| 236 | const struct i2c_device_id *id) |
| 237 | { |
| 238 | struct i2c_adapter *adapter = client->adapter; |
| 239 | struct ina2xx_data *data; |
| 240 | struct ina2xx_platform_data *pdata; |
| 241 | int ret = 0; |
| 242 | long shunt = 10000; /* default shunt value 10mOhms */ |
| 243 | |
| 244 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) |
| 245 | return -ENODEV; |
| 246 | |
| 247 | data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); |
| 248 | if (!data) |
| 249 | return -ENOMEM; |
| 250 | |
| 251 | if (client->dev.platform_data) { |
| 252 | pdata = |
| 253 | (struct ina2xx_platform_data *)client->dev.platform_data; |
| 254 | shunt = pdata->shunt_uohms; |
| 255 | } |
| 256 | |
| 257 | if (shunt <= 0) |
| 258 | return -ENODEV; |
| 259 | |
| 260 | /* set the device type */ |
| 261 | data->kind = id->driver_data; |
| 262 | |
| 263 | switch (data->kind) { |
| 264 | case ina219: |
| 265 | /* device configuration */ |
Guenter Roeck | 080b98e | 2012-09-11 08:22:14 -0700 | [diff] [blame^] | 266 | i2c_smbus_write_word_swapped(client, INA2XX_CONFIG, |
| 267 | INA219_CONFIG_DEFAULT); |
Felten, Lothar | f7c2fe3 | 2012-05-12 04:36:38 -0400 | [diff] [blame] | 268 | |
| 269 | /* set current LSB to 1mA, shunt is in uOhms */ |
| 270 | /* (equation 13 in datasheet) */ |
Guenter Roeck | 080b98e | 2012-09-11 08:22:14 -0700 | [diff] [blame^] | 271 | i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION, |
| 272 | 40960000 / shunt); |
Felten, Lothar | f7c2fe3 | 2012-05-12 04:36:38 -0400 | [diff] [blame] | 273 | dev_info(&client->dev, |
| 274 | "power monitor INA219 (Rshunt = %li uOhm)\n", shunt); |
| 275 | data->registers = INA219_REGISTERS; |
| 276 | break; |
| 277 | case ina226: |
| 278 | /* device configuration */ |
Guenter Roeck | 080b98e | 2012-09-11 08:22:14 -0700 | [diff] [blame^] | 279 | i2c_smbus_write_word_swapped(client, INA2XX_CONFIG, |
| 280 | INA226_CONFIG_DEFAULT); |
Felten, Lothar | f7c2fe3 | 2012-05-12 04:36:38 -0400 | [diff] [blame] | 281 | |
| 282 | /* set current LSB to 1mA, shunt is in uOhms */ |
| 283 | /* (equation 1 in datasheet)*/ |
Guenter Roeck | 080b98e | 2012-09-11 08:22:14 -0700 | [diff] [blame^] | 284 | i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION, |
| 285 | 5120000 / shunt); |
Felten, Lothar | f7c2fe3 | 2012-05-12 04:36:38 -0400 | [diff] [blame] | 286 | dev_info(&client->dev, |
| 287 | "power monitor INA226 (Rshunt = %li uOhm)\n", shunt); |
| 288 | data->registers = INA226_REGISTERS; |
| 289 | break; |
| 290 | default: |
| 291 | /* unknown device id */ |
| 292 | return -ENODEV; |
| 293 | } |
| 294 | |
| 295 | i2c_set_clientdata(client, data); |
| 296 | mutex_init(&data->update_lock); |
| 297 | |
| 298 | ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group); |
| 299 | if (ret) |
| 300 | return ret; |
| 301 | |
| 302 | data->hwmon_dev = hwmon_device_register(&client->dev); |
| 303 | if (IS_ERR(data->hwmon_dev)) { |
| 304 | ret = PTR_ERR(data->hwmon_dev); |
| 305 | goto out_err_hwmon; |
| 306 | } |
| 307 | |
| 308 | return 0; |
| 309 | |
| 310 | out_err_hwmon: |
| 311 | sysfs_remove_group(&client->dev.kobj, &ina2xx_group); |
| 312 | return ret; |
| 313 | } |
| 314 | |
| 315 | static int ina2xx_remove(struct i2c_client *client) |
| 316 | { |
| 317 | struct ina2xx_data *data = i2c_get_clientdata(client); |
| 318 | |
| 319 | hwmon_device_unregister(data->hwmon_dev); |
| 320 | sysfs_remove_group(&client->dev.kobj, &ina2xx_group); |
| 321 | |
| 322 | return 0; |
| 323 | } |
| 324 | |
| 325 | static const struct i2c_device_id ina2xx_id[] = { |
| 326 | { "ina219", ina219 }, |
| 327 | { "ina226", ina226 }, |
| 328 | { } |
| 329 | }; |
| 330 | MODULE_DEVICE_TABLE(i2c, ina2xx_id); |
| 331 | |
| 332 | static struct i2c_driver ina2xx_driver = { |
| 333 | .driver = { |
| 334 | .name = "ina2xx", |
| 335 | }, |
| 336 | .probe = ina2xx_probe, |
| 337 | .remove = ina2xx_remove, |
| 338 | .id_table = ina2xx_id, |
| 339 | }; |
| 340 | |
| 341 | static int __init ina2xx_init(void) |
| 342 | { |
| 343 | return i2c_add_driver(&ina2xx_driver); |
| 344 | } |
| 345 | |
| 346 | static void __exit ina2xx_exit(void) |
| 347 | { |
| 348 | i2c_del_driver(&ina2xx_driver); |
| 349 | } |
| 350 | |
| 351 | MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>"); |
| 352 | MODULE_DESCRIPTION("ina2xx driver"); |
| 353 | MODULE_LICENSE("GPL"); |
| 354 | |
| 355 | module_init(ina2xx_init); |
| 356 | module_exit(ina2xx_exit); |