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| 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 | + |
| 72 | +int ina2xx_read_word(struct i2c_client *client, int reg) |
| 73 | +{ |
| 74 | + int val = i2c_smbus_read_word_data(client, reg); |
| 75 | + if (unlikely(val < 0)) { |
| 76 | + dev_dbg(&client->dev, |
| 77 | + "Failed to read register: %d\n", reg); |
| 78 | + return val; |
| 79 | + } |
| 80 | + return be16_to_cpu(val); |
| 81 | +} |
| 82 | + |
| 83 | +void ina2xx_write_word(struct i2c_client *client, int reg, int data) |
| 84 | +{ |
| 85 | + i2c_smbus_write_word_data(client, reg, cpu_to_be16(data)); |
| 86 | +} |
| 87 | + |
| 88 | +static struct ina2xx_data *ina2xx_update_device(struct device *dev) |
| 89 | +{ |
| 90 | + struct i2c_client *client = to_i2c_client(dev); |
| 91 | + struct ina2xx_data *data = i2c_get_clientdata(client); |
| 92 | + struct ina2xx_data *ret = data; |
| 93 | + |
| 94 | + mutex_lock(&data->update_lock); |
| 95 | + |
| 96 | + if (time_after(jiffies, data->last_updated + |
| 97 | + HZ / INA2XX_CONVERSION_RATE) || !data->valid) { |
| 98 | + |
| 99 | + int i; |
| 100 | + |
| 101 | + dev_dbg(&client->dev, "Starting ina2xx update\n"); |
| 102 | + |
| 103 | + /* Read all registers */ |
| 104 | + for (i = 0; i < data->registers; i++) { |
| 105 | + int rv = ina2xx_read_word(client, i); |
| 106 | + if (rv < 0) { |
| 107 | + ret = ERR_PTR(rv); |
| 108 | + goto abort; |
| 109 | + } |
| 110 | + data->regs[i] = rv; |
| 111 | + } |
| 112 | + data->last_updated = jiffies; |
| 113 | + data->valid = 1; |
| 114 | + } |
| 115 | +abort: |
| 116 | + mutex_unlock(&data->update_lock); |
| 117 | + return ret; |
| 118 | +} |
| 119 | + |
| 120 | +static int ina219_get_value(struct ina2xx_data *data, u8 reg) |
| 121 | +{ |
| 122 | + /* |
| 123 | + * calculate exact value for the given register |
| 124 | + * we assume default power-on reset settings: |
| 125 | + * bus voltage range 32V |
| 126 | + * gain = /8 |
| 127 | + * adc 1 & 2 -> conversion time 532uS |
| 128 | + * mode is continuous shunt and bus |
| 129 | + * calibration value is INA219_CALIBRATION_VALUE |
| 130 | + */ |
| 131 | + int val = data->regs[reg]; |
| 132 | + |
| 133 | + switch (reg) { |
| 134 | + case INA2XX_SHUNT_VOLTAGE: |
| 135 | + /* LSB=10uV. Convert to mV. */ |
| 136 | + val = DIV_ROUND_CLOSEST(val, 100); |
| 137 | + break; |
| 138 | + case INA2XX_BUS_VOLTAGE: |
| 139 | + /* LSB=4mV. Register is not right aligned, convert to mV. */ |
| 140 | + val = (val >> 3) * 4; |
| 141 | + break; |
| 142 | + case INA2XX_POWER: |
| 143 | + /* LSB=20mW. Convert to uW */ |
| 144 | + val = val * 20 * 1000; |
| 145 | + break; |
| 146 | + case INA2XX_CURRENT: |
| 147 | + /* LSB=1mA (selected). Is in mA */ |
| 148 | + break; |
| 149 | + default: |
| 150 | + /* programmer goofed */ |
| 151 | + WARN_ON_ONCE(1); |
| 152 | + val = 0; |
| 153 | + break; |
| 154 | + } |
| 155 | + |
| 156 | + return val; |
| 157 | +} |
| 158 | + |
| 159 | +static int ina226_get_value(struct ina2xx_data *data, u8 reg) |
| 160 | +{ |
| 161 | + /* |
| 162 | + * calculate exact value for the given register |
| 163 | + * we assume default power-on reset settings: |
| 164 | + * bus voltage range 32V |
| 165 | + * gain = /8 |
| 166 | + * adc 1 & 2 -> conversion time 532uS |
| 167 | + * mode is continuous shunt and bus |
| 168 | + * calibration value is INA226_CALIBRATION_VALUE |
| 169 | + */ |
| 170 | + int val = data->regs[reg]; |
| 171 | + |
| 172 | + switch (reg) { |
| 173 | + case INA2XX_SHUNT_VOLTAGE: |
| 174 | + /* LSB=2.5uV. Convert to mV. */ |
| 175 | + val = DIV_ROUND_CLOSEST(val, 400); |
| 176 | + break; |
| 177 | + case INA2XX_BUS_VOLTAGE: |
| 178 | + /* LSB=1.25mV. Convert to mV. */ |
| 179 | + val = val + DIV_ROUND_CLOSEST(val, 4); |
| 180 | + break; |
| 181 | + case INA2XX_POWER: |
| 182 | + /* LSB=25mW. Convert to uW */ |
| 183 | + val = val * 25 * 1000; |
| 184 | + break; |
| 185 | + case INA2XX_CURRENT: |
| 186 | + /* LSB=1mA (selected). Is in mA */ |
| 187 | + break; |
| 188 | + default: |
| 189 | + /* programmer goofed */ |
| 190 | + WARN_ON_ONCE(1); |
| 191 | + val = 0; |
| 192 | + break; |
| 193 | + } |
| 194 | + |
| 195 | + return val; |
| 196 | +} |
| 197 | + |
| 198 | +static ssize_t ina2xx_show_value(struct device *dev, |
| 199 | + struct device_attribute *da, char *buf) |
| 200 | +{ |
| 201 | + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); |
| 202 | + struct ina2xx_data *data = ina2xx_update_device(dev); |
| 203 | + int value = 0; |
| 204 | + |
| 205 | + if (IS_ERR(data)) |
| 206 | + return PTR_ERR(data); |
| 207 | + |
| 208 | + switch (data->kind) { |
| 209 | + case ina219: |
| 210 | + value = ina219_get_value(data, attr->index); |
| 211 | + break; |
| 212 | + case ina226: |
| 213 | + value = ina226_get_value(data, attr->index); |
| 214 | + break; |
| 215 | + default: |
| 216 | + WARN_ON_ONCE(1); |
| 217 | + break; |
| 218 | + } |
| 219 | + return snprintf(buf, PAGE_SIZE, "%d\n", value); |
| 220 | +} |
| 221 | + |
| 222 | +/* shunt voltage */ |
| 223 | +static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, \ |
| 224 | + ina2xx_show_value, NULL, INA2XX_SHUNT_VOLTAGE); |
| 225 | + |
| 226 | +/* bus voltage */ |
| 227 | +static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, \ |
| 228 | + ina2xx_show_value, NULL, INA2XX_BUS_VOLTAGE); |
| 229 | + |
| 230 | +/* calculated current */ |
| 231 | +static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, \ |
| 232 | + ina2xx_show_value, NULL, INA2XX_CURRENT); |
| 233 | + |
| 234 | +/* calculated power */ |
| 235 | +static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, \ |
| 236 | + ina2xx_show_value, NULL, INA2XX_POWER); |
| 237 | + |
| 238 | +/* pointers to created device attributes */ |
| 239 | +static struct attribute *ina2xx_attributes[] = { |
| 240 | + &sensor_dev_attr_in0_input.dev_attr.attr, |
| 241 | + &sensor_dev_attr_in1_input.dev_attr.attr, |
| 242 | + &sensor_dev_attr_curr1_input.dev_attr.attr, |
| 243 | + &sensor_dev_attr_power1_input.dev_attr.attr, |
| 244 | + NULL, |
| 245 | +}; |
| 246 | + |
| 247 | +static const struct attribute_group ina2xx_group = { |
| 248 | + .attrs = ina2xx_attributes, |
| 249 | +}; |
| 250 | + |
| 251 | +static int ina2xx_probe(struct i2c_client *client, |
| 252 | + const struct i2c_device_id *id) |
| 253 | +{ |
| 254 | + struct i2c_adapter *adapter = client->adapter; |
| 255 | + struct ina2xx_data *data; |
| 256 | + struct ina2xx_platform_data *pdata; |
| 257 | + int ret = 0; |
| 258 | + long shunt = 10000; /* default shunt value 10mOhms */ |
| 259 | + |
| 260 | + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) |
| 261 | + return -ENODEV; |
| 262 | + |
| 263 | + data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); |
| 264 | + if (!data) |
| 265 | + return -ENOMEM; |
| 266 | + |
| 267 | + if (client->dev.platform_data) { |
| 268 | + pdata = |
| 269 | + (struct ina2xx_platform_data *)client->dev.platform_data; |
| 270 | + shunt = pdata->shunt_uohms; |
| 271 | + } |
| 272 | + |
| 273 | + if (shunt <= 0) |
| 274 | + return -ENODEV; |
| 275 | + |
| 276 | + /* set the device type */ |
| 277 | + data->kind = id->driver_data; |
| 278 | + |
| 279 | + switch (data->kind) { |
| 280 | + case ina219: |
| 281 | + /* device configuration */ |
| 282 | + ina2xx_write_word(client, INA2XX_CONFIG, INA219_CONFIG_DEFAULT); |
| 283 | + |
| 284 | + /* set current LSB to 1mA, shunt is in uOhms */ |
| 285 | + /* (equation 13 in datasheet) */ |
| 286 | + ina2xx_write_word(client, INA2XX_CALIBRATION, 40960000 / shunt); |
| 287 | + dev_info(&client->dev, |
| 288 | + "power monitor INA219 (Rshunt = %li uOhm)\n", shunt); |
| 289 | + data->registers = INA219_REGISTERS; |
| 290 | + break; |
| 291 | + case ina226: |
| 292 | + /* device configuration */ |
| 293 | + ina2xx_write_word(client, INA2XX_CONFIG, INA226_CONFIG_DEFAULT); |
| 294 | + |
| 295 | + /* set current LSB to 1mA, shunt is in uOhms */ |
| 296 | + /* (equation 1 in datasheet)*/ |
| 297 | + ina2xx_write_word(client, INA2XX_CALIBRATION, 5120000 / shunt); |
| 298 | + dev_info(&client->dev, |
| 299 | + "power monitor INA226 (Rshunt = %li uOhm)\n", shunt); |
| 300 | + data->registers = INA226_REGISTERS; |
| 301 | + break; |
| 302 | + default: |
| 303 | + /* unknown device id */ |
| 304 | + return -ENODEV; |
| 305 | + } |
| 306 | + |
| 307 | + i2c_set_clientdata(client, data); |
| 308 | + mutex_init(&data->update_lock); |
| 309 | + |
| 310 | + ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group); |
| 311 | + if (ret) |
| 312 | + return ret; |
| 313 | + |
| 314 | + data->hwmon_dev = hwmon_device_register(&client->dev); |
| 315 | + if (IS_ERR(data->hwmon_dev)) { |
| 316 | + ret = PTR_ERR(data->hwmon_dev); |
| 317 | + goto out_err_hwmon; |
| 318 | + } |
| 319 | + |
| 320 | + return 0; |
| 321 | + |
| 322 | +out_err_hwmon: |
| 323 | + sysfs_remove_group(&client->dev.kobj, &ina2xx_group); |
| 324 | + return ret; |
| 325 | +} |
| 326 | + |
| 327 | +static int ina2xx_remove(struct i2c_client *client) |
| 328 | +{ |
| 329 | + struct ina2xx_data *data = i2c_get_clientdata(client); |
| 330 | + |
| 331 | + hwmon_device_unregister(data->hwmon_dev); |
| 332 | + sysfs_remove_group(&client->dev.kobj, &ina2xx_group); |
| 333 | + |
| 334 | + return 0; |
| 335 | +} |
| 336 | + |
| 337 | +static const struct i2c_device_id ina2xx_id[] = { |
| 338 | + { "ina219", ina219 }, |
| 339 | + { "ina226", ina226 }, |
| 340 | + { } |
| 341 | +}; |
| 342 | +MODULE_DEVICE_TABLE(i2c, ina2xx_id); |
| 343 | + |
| 344 | +static struct i2c_driver ina2xx_driver = { |
| 345 | + .driver = { |
| 346 | + .name = "ina2xx", |
| 347 | + }, |
| 348 | + .probe = ina2xx_probe, |
| 349 | + .remove = ina2xx_remove, |
| 350 | + .id_table = ina2xx_id, |
| 351 | +}; |
| 352 | + |
| 353 | +static int __init ina2xx_init(void) |
| 354 | +{ |
| 355 | + return i2c_add_driver(&ina2xx_driver); |
| 356 | +} |
| 357 | + |
| 358 | +static void __exit ina2xx_exit(void) |
| 359 | +{ |
| 360 | + i2c_del_driver(&ina2xx_driver); |
| 361 | +} |
| 362 | + |
| 363 | +MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>"); |
| 364 | +MODULE_DESCRIPTION("ina2xx driver"); |
| 365 | +MODULE_LICENSE("GPL"); |
| 366 | + |
| 367 | +module_init(ina2xx_init); |
| 368 | +module_exit(ina2xx_exit); |