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 * INA220: 9 * Bi-Directional Current/Power Monitor with I2C Interface 10 * Datasheet: http://www.ti.com/product/ina220 11 * 12 * INA226: 13 * Bi-Directional Current/Power Monitor with I2C Interface 14 * Datasheet: http://www.ti.com/product/ina226 15 * 16 * INA230: 17 * Bi-directional Current/Power Monitor with I2C Interface 18 * Datasheet: http://www.ti.com/product/ina230 19 * 20 * Copyright (C) 2012 Lothar Felten <lothar.felten@gmail.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> 36 #include <linux/jiffies.h> 37 #include <linux/of_device.h> 38 #include <linux/of.h> 39 #include <linux/delay.h> 40 #include <linux/util_macros.h> 41 #include <linux/regmap.h> 42 43 #include <linux/platform_data/ina2xx.h> 44 45 /* common register definitions */ 46 #define INA2XX_CONFIG 0x00 47 #define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */ 48 #define INA2XX_BUS_VOLTAGE 0x02 /* readonly */ 49 #define INA2XX_POWER 0x03 /* readonly */ 50 #define INA2XX_CURRENT 0x04 /* readonly */ 51 #define INA2XX_CALIBRATION 0x05 52 53 /* INA226 register definitions */ 54 #define INA226_MASK_ENABLE 0x06 55 #define INA226_ALERT_LIMIT 0x07 56 #define INA226_DIE_ID 0xFF 57 58 /* register count */ 59 #define INA219_REGISTERS 6 60 #define INA226_REGISTERS 8 61 62 #define INA2XX_MAX_REGISTERS 8 63 64 /* settings - depend on use case */ 65 #define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */ 66 #define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */ 67 68 /* worst case is 68.10 ms (~14.6Hz, ina219) */ 69 #define INA2XX_CONVERSION_RATE 15 70 #define INA2XX_MAX_DELAY 69 /* worst case delay in ms */ 71 72 #define INA2XX_RSHUNT_DEFAULT 10000 73 74 /* bit mask for reading the averaging setting in the configuration register */ 75 #define INA226_AVG_RD_MASK 0x0E00 76 77 #define INA226_READ_AVG(reg) (((reg) & INA226_AVG_RD_MASK) >> 9) 78 #define INA226_SHIFT_AVG(val) ((val) << 9) 79 80 /* common attrs, ina226 attrs and NULL */ 81 #define INA2XX_MAX_ATTRIBUTE_GROUPS 3 82 83 /* 84 * Both bus voltage and shunt voltage conversion times for ina226 are set 85 * to 0b0100 on POR, which translates to 2200 microseconds in total. 86 */ 87 #define INA226_TOTAL_CONV_TIME_DEFAULT 2200 88 89 static struct regmap_config ina2xx_regmap_config = { 90 .reg_bits = 8, 91 .val_bits = 16, 92 }; 93 94 enum ina2xx_ids { ina219, ina226 }; 95 96 struct ina2xx_config { 97 u16 config_default; 98 int calibration_value; 99 int registers; 100 int shunt_div; 101 int bus_voltage_shift; 102 int bus_voltage_lsb; /* uV */ 103 int power_lsb_factor; 104 }; 105 106 struct ina2xx_data { 107 const struct ina2xx_config *config; 108 109 long rshunt; 110 long current_lsb_uA; 111 long power_lsb_uW; 112 struct mutex config_lock; 113 struct regmap *regmap; 114 115 const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS]; 116 }; 117 118 static const struct ina2xx_config ina2xx_config[] = { 119 [ina219] = { 120 .config_default = INA219_CONFIG_DEFAULT, 121 .calibration_value = 4096, 122 .registers = INA219_REGISTERS, 123 .shunt_div = 100, 124 .bus_voltage_shift = 3, 125 .bus_voltage_lsb = 4000, 126 .power_lsb_factor = 20, 127 }, 128 [ina226] = { 129 .config_default = INA226_CONFIG_DEFAULT, 130 .calibration_value = 2048, 131 .registers = INA226_REGISTERS, 132 .shunt_div = 400, 133 .bus_voltage_shift = 0, 134 .bus_voltage_lsb = 1250, 135 .power_lsb_factor = 25, 136 }, 137 }; 138 139 /* 140 * Available averaging rates for ina226. The indices correspond with 141 * the bit values expected by the chip (according to the ina226 datasheet, 142 * table 3 AVG bit settings, found at 143 * http://www.ti.com/lit/ds/symlink/ina226.pdf. 144 */ 145 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 }; 146 147 static int ina226_reg_to_interval(u16 config) 148 { 149 int avg = ina226_avg_tab[INA226_READ_AVG(config)]; 150 151 /* 152 * Multiply the total conversion time by the number of averages. 153 * Return the result in milliseconds. 154 */ 155 return DIV_ROUND_CLOSEST(avg * INA226_TOTAL_CONV_TIME_DEFAULT, 1000); 156 } 157 158 /* 159 * Return the new, shifted AVG field value of CONFIG register, 160 * to use with regmap_update_bits 161 */ 162 static u16 ina226_interval_to_reg(int interval) 163 { 164 int avg, avg_bits; 165 166 avg = DIV_ROUND_CLOSEST(interval * 1000, 167 INA226_TOTAL_CONV_TIME_DEFAULT); 168 avg_bits = find_closest(avg, ina226_avg_tab, 169 ARRAY_SIZE(ina226_avg_tab)); 170 171 return INA226_SHIFT_AVG(avg_bits); 172 } 173 174 /* 175 * Calibration register is set to the best value, which eliminates 176 * truncation errors on calculating current register in hardware. 177 * According to datasheet (eq. 3) the best values are 2048 for 178 * ina226 and 4096 for ina219. They are hardcoded as calibration_value. 179 */ 180 static int ina2xx_calibrate(struct ina2xx_data *data) 181 { 182 return regmap_write(data->regmap, INA2XX_CALIBRATION, 183 data->config->calibration_value); 184 } 185 186 /* 187 * Initialize the configuration and calibration registers. 188 */ 189 static int ina2xx_init(struct ina2xx_data *data) 190 { 191 int ret = regmap_write(data->regmap, INA2XX_CONFIG, 192 data->config->config_default); 193 if (ret < 0) 194 return ret; 195 196 return ina2xx_calibrate(data); 197 } 198 199 static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval) 200 { 201 struct ina2xx_data *data = dev_get_drvdata(dev); 202 int ret, retry; 203 204 dev_dbg(dev, "Starting register %d read\n", reg); 205 206 for (retry = 5; retry; retry--) { 207 208 ret = regmap_read(data->regmap, reg, regval); 209 if (ret < 0) 210 return ret; 211 212 dev_dbg(dev, "read %d, val = 0x%04x\n", reg, *regval); 213 214 /* 215 * If the current value in the calibration register is 0, the 216 * power and current registers will also remain at 0. In case 217 * the chip has been reset let's check the calibration 218 * register and reinitialize if needed. 219 * We do that extra read of the calibration register if there 220 * is some hint of a chip reset. 221 */ 222 if (*regval == 0) { 223 unsigned int cal; 224 225 ret = regmap_read(data->regmap, INA2XX_CALIBRATION, 226 &cal); 227 if (ret < 0) 228 return ret; 229 230 if (cal == 0) { 231 dev_warn(dev, "chip not calibrated, reinitializing\n"); 232 233 ret = ina2xx_init(data); 234 if (ret < 0) 235 return ret; 236 /* 237 * Let's make sure the power and current 238 * registers have been updated before trying 239 * again. 240 */ 241 msleep(INA2XX_MAX_DELAY); 242 continue; 243 } 244 } 245 return 0; 246 } 247 248 /* 249 * If we're here then although all write operations succeeded, the 250 * chip still returns 0 in the calibration register. Nothing more we 251 * can do here. 252 */ 253 dev_err(dev, "unable to reinitialize the chip\n"); 254 return -ENODEV; 255 } 256 257 static int ina2xx_get_value(struct ina2xx_data *data, u8 reg, 258 unsigned int regval) 259 { 260 int val; 261 262 switch (reg) { 263 case INA2XX_SHUNT_VOLTAGE: 264 /* signed register */ 265 val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div); 266 break; 267 case INA2XX_BUS_VOLTAGE: 268 val = (regval >> data->config->bus_voltage_shift) 269 * data->config->bus_voltage_lsb; 270 val = DIV_ROUND_CLOSEST(val, 1000); 271 break; 272 case INA2XX_POWER: 273 val = regval * data->power_lsb_uW; 274 break; 275 case INA2XX_CURRENT: 276 /* signed register, result in mA */ 277 val = (s16)regval * data->current_lsb_uA; 278 val = DIV_ROUND_CLOSEST(val, 1000); 279 break; 280 case INA2XX_CALIBRATION: 281 val = regval; 282 break; 283 default: 284 /* programmer goofed */ 285 WARN_ON_ONCE(1); 286 val = 0; 287 break; 288 } 289 290 return val; 291 } 292 293 static ssize_t ina2xx_value_show(struct device *dev, 294 struct device_attribute *da, char *buf) 295 { 296 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 297 struct ina2xx_data *data = dev_get_drvdata(dev); 298 unsigned int regval; 299 300 int err = ina2xx_read_reg(dev, attr->index, ®val); 301 302 if (err < 0) 303 return err; 304 305 return snprintf(buf, PAGE_SIZE, "%d\n", 306 ina2xx_get_value(data, attr->index, regval)); 307 } 308 309 /* 310 * In order to keep calibration register value fixed, the product 311 * of current_lsb and shunt_resistor should also be fixed and equal 312 * to shunt_voltage_lsb = 1 / shunt_div multiplied by 10^9 in order 313 * to keep the scale. 314 */ 315 static int ina2xx_set_shunt(struct ina2xx_data *data, long val) 316 { 317 unsigned int dividend = DIV_ROUND_CLOSEST(1000000000, 318 data->config->shunt_div); 319 if (val <= 0 || val > dividend) 320 return -EINVAL; 321 322 mutex_lock(&data->config_lock); 323 data->rshunt = val; 324 data->current_lsb_uA = DIV_ROUND_CLOSEST(dividend, val); 325 data->power_lsb_uW = data->config->power_lsb_factor * 326 data->current_lsb_uA; 327 mutex_unlock(&data->config_lock); 328 329 return 0; 330 } 331 332 static ssize_t ina2xx_shunt_show(struct device *dev, 333 struct device_attribute *da, char *buf) 334 { 335 struct ina2xx_data *data = dev_get_drvdata(dev); 336 337 return snprintf(buf, PAGE_SIZE, "%li\n", data->rshunt); 338 } 339 340 static ssize_t ina2xx_shunt_store(struct device *dev, 341 struct device_attribute *da, 342 const char *buf, size_t count) 343 { 344 unsigned long val; 345 int status; 346 struct ina2xx_data *data = dev_get_drvdata(dev); 347 348 status = kstrtoul(buf, 10, &val); 349 if (status < 0) 350 return status; 351 352 status = ina2xx_set_shunt(data, val); 353 if (status < 0) 354 return status; 355 return count; 356 } 357 358 static ssize_t ina226_interval_store(struct device *dev, 359 struct device_attribute *da, 360 const char *buf, size_t count) 361 { 362 struct ina2xx_data *data = dev_get_drvdata(dev); 363 unsigned long val; 364 int status; 365 366 status = kstrtoul(buf, 10, &val); 367 if (status < 0) 368 return status; 369 370 if (val > INT_MAX || val == 0) 371 return -EINVAL; 372 373 status = regmap_update_bits(data->regmap, INA2XX_CONFIG, 374 INA226_AVG_RD_MASK, 375 ina226_interval_to_reg(val)); 376 if (status < 0) 377 return status; 378 379 return count; 380 } 381 382 static ssize_t ina226_interval_show(struct device *dev, 383 struct device_attribute *da, char *buf) 384 { 385 struct ina2xx_data *data = dev_get_drvdata(dev); 386 int status; 387 unsigned int regval; 388 389 status = regmap_read(data->regmap, INA2XX_CONFIG, ®val); 390 if (status) 391 return status; 392 393 return snprintf(buf, PAGE_SIZE, "%d\n", ina226_reg_to_interval(regval)); 394 } 395 396 /* shunt voltage */ 397 static SENSOR_DEVICE_ATTR_RO(in0_input, ina2xx_value, INA2XX_SHUNT_VOLTAGE); 398 399 /* bus voltage */ 400 static SENSOR_DEVICE_ATTR_RO(in1_input, ina2xx_value, INA2XX_BUS_VOLTAGE); 401 402 /* calculated current */ 403 static SENSOR_DEVICE_ATTR_RO(curr1_input, ina2xx_value, INA2XX_CURRENT); 404 405 /* calculated power */ 406 static SENSOR_DEVICE_ATTR_RO(power1_input, ina2xx_value, INA2XX_POWER); 407 408 /* shunt resistance */ 409 static SENSOR_DEVICE_ATTR_RW(shunt_resistor, ina2xx_shunt, INA2XX_CALIBRATION); 410 411 /* update interval (ina226 only) */ 412 static SENSOR_DEVICE_ATTR_RW(update_interval, ina226_interval, 0); 413 414 /* pointers to created device attributes */ 415 static struct attribute *ina2xx_attrs[] = { 416 &sensor_dev_attr_in0_input.dev_attr.attr, 417 &sensor_dev_attr_in1_input.dev_attr.attr, 418 &sensor_dev_attr_curr1_input.dev_attr.attr, 419 &sensor_dev_attr_power1_input.dev_attr.attr, 420 &sensor_dev_attr_shunt_resistor.dev_attr.attr, 421 NULL, 422 }; 423 424 static const struct attribute_group ina2xx_group = { 425 .attrs = ina2xx_attrs, 426 }; 427 428 static struct attribute *ina226_attrs[] = { 429 &sensor_dev_attr_update_interval.dev_attr.attr, 430 NULL, 431 }; 432 433 static const struct attribute_group ina226_group = { 434 .attrs = ina226_attrs, 435 }; 436 437 static int ina2xx_probe(struct i2c_client *client, 438 const struct i2c_device_id *id) 439 { 440 struct device *dev = &client->dev; 441 struct ina2xx_data *data; 442 struct device *hwmon_dev; 443 u32 val; 444 int ret, group = 0; 445 enum ina2xx_ids chip; 446 447 if (client->dev.of_node) 448 chip = (enum ina2xx_ids)of_device_get_match_data(&client->dev); 449 else 450 chip = id->driver_data; 451 452 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 453 if (!data) 454 return -ENOMEM; 455 456 /* set the device type */ 457 data->config = &ina2xx_config[chip]; 458 mutex_init(&data->config_lock); 459 460 if (of_property_read_u32(dev->of_node, "shunt-resistor", &val) < 0) { 461 struct ina2xx_platform_data *pdata = dev_get_platdata(dev); 462 463 if (pdata) 464 val = pdata->shunt_uohms; 465 else 466 val = INA2XX_RSHUNT_DEFAULT; 467 } 468 469 ina2xx_set_shunt(data, val); 470 471 ina2xx_regmap_config.max_register = data->config->registers; 472 473 data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config); 474 if (IS_ERR(data->regmap)) { 475 dev_err(dev, "failed to allocate register map\n"); 476 return PTR_ERR(data->regmap); 477 } 478 479 ret = ina2xx_init(data); 480 if (ret < 0) { 481 dev_err(dev, "error configuring the device: %d\n", ret); 482 return -ENODEV; 483 } 484 485 data->groups[group++] = &ina2xx_group; 486 if (chip == ina226) 487 data->groups[group++] = &ina226_group; 488 489 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 490 data, data->groups); 491 if (IS_ERR(hwmon_dev)) 492 return PTR_ERR(hwmon_dev); 493 494 dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n", 495 client->name, data->rshunt); 496 497 return 0; 498 } 499 500 static const struct i2c_device_id ina2xx_id[] = { 501 { "ina219", ina219 }, 502 { "ina220", ina219 }, 503 { "ina226", ina226 }, 504 { "ina230", ina226 }, 505 { "ina231", ina226 }, 506 { } 507 }; 508 MODULE_DEVICE_TABLE(i2c, ina2xx_id); 509 510 static const struct of_device_id __maybe_unused ina2xx_of_match[] = { 511 { 512 .compatible = "ti,ina219", 513 .data = (void *)ina219 514 }, 515 { 516 .compatible = "ti,ina220", 517 .data = (void *)ina219 518 }, 519 { 520 .compatible = "ti,ina226", 521 .data = (void *)ina226 522 }, 523 { 524 .compatible = "ti,ina230", 525 .data = (void *)ina226 526 }, 527 { 528 .compatible = "ti,ina231", 529 .data = (void *)ina226 530 }, 531 { }, 532 }; 533 MODULE_DEVICE_TABLE(of, ina2xx_of_match); 534 535 static struct i2c_driver ina2xx_driver = { 536 .driver = { 537 .name = "ina2xx", 538 .of_match_table = of_match_ptr(ina2xx_of_match), 539 }, 540 .probe = ina2xx_probe, 541 .id_table = ina2xx_id, 542 }; 543 544 module_i2c_driver(ina2xx_driver); 545 546 MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>"); 547 MODULE_DESCRIPTION("ina2xx driver"); 548 MODULE_LICENSE("GPL"); 549