drivers/hwmon/ina2xx.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for Texas Instruments INA219, INA226 power monitor chips
   4  *
   5  * INA219:
   6  * Zero Drift Bi-Directional Current/Power Monitor with I2C Interface
   7  * Datasheet: http://www.ti.com/product/ina219
   8  *
   9  * INA220:
  10  * Bi-Directional Current/Power Monitor with I2C Interface
  11  * Datasheet: http://www.ti.com/product/ina220
  12  *
  13  * INA226:
  14  * Bi-Directional Current/Power Monitor with I2C Interface
  15  * Datasheet: http://www.ti.com/product/ina226
  16  *
  17  * INA230:
  18  * Bi-directional Current/Power Monitor with I2C Interface
  19  * Datasheet: http://www.ti.com/product/ina230
  20  *
  21  * Copyright (C) 2012 Lothar Felten <lothar.felten@gmail.com>
  22  * Thanks to Jan Volkering
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/init.h>
  28 #include <linux/err.h>
  29 #include <linux/slab.h>
  30 #include <linux/i2c.h>
  31 #include <linux/hwmon.h>
  32 #include <linux/hwmon-sysfs.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/of_device.h>
  35 #include <linux/of.h>
  36 #include <linux/delay.h>
  37 #include <linux/util_macros.h>
  38 #include <linux/regmap.h>
  39
  40 #include <linux/platform_data/ina2xx.h>
  41
  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
  49
  50 /* INA226 register definitions */
  51 #define INA226_MASK_ENABLE              0x06
  52 #define INA226_ALERT_LIMIT              0x07
  53 #define INA226_DIE_ID                   0xFF
  54
  55 /* register count */
  56 #define INA219_REGISTERS                6
  57 #define INA226_REGISTERS                8
  58
  59 #define INA2XX_MAX_REGISTERS            8
  60
  61 /* settings - depend on use case */
  62 #define INA219_CONFIG_DEFAULT           0x399F  /* PGA=8 */
  63 #define INA226_CONFIG_DEFAULT           0x4527  /* averages=16 */
  64
  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 */
  68
  69 #define INA2XX_RSHUNT_DEFAULT           10000
  70
  71 /* bit mask for reading the averaging setting in the configuration register */
  72 #define INA226_AVG_RD_MASK              0x0E00
  73
  74 #define INA226_READ_AVG(reg)            (((reg) & INA226_AVG_RD_MASK) >> 9)
  75 #define INA226_SHIFT_AVG(val)           ((val) << 9)
  76
  77 /* common attrs, ina226 attrs and NULL */
  78 #define INA2XX_MAX_ATTRIBUTE_GROUPS     3
  79
  80 /*
  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.
  83  */
  84 #define INA226_TOTAL_CONV_TIME_DEFAULT  2200
  85
  86 static struct regmap_config ina2xx_regmap_config = {
  87         .reg_bits = 8,
  88         .val_bits = 16,
  89 };
  90
  91 enum ina2xx_ids { ina219, ina226 };
  92
  93 struct ina2xx_config {
  94         u16 config_default;
  95         int calibration_value;
  96         int registers;
  97         int shunt_div;
  98         int bus_voltage_shift;
  99         int bus_voltage_lsb;    /* uV */
 100         int power_lsb_factor;
 101 };
 102
 103 struct ina2xx_data {
 104         const struct ina2xx_config *config;
 105
 106         long rshunt;
 107         long current_lsb_uA;
 108         long power_lsb_uW;
 109         struct mutex config_lock;
 110         struct regmap *regmap;
 111
 112         const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
 113 };
 114
 115 static const struct ina2xx_config ina2xx_config[] = {
 116         [ina219] = {
 117                 .config_default = INA219_CONFIG_DEFAULT,
 118                 .calibration_value = 4096,
 119                 .registers = INA219_REGISTERS,
 120                 .shunt_div = 100,
 121                 .bus_voltage_shift = 3,
 122                 .bus_voltage_lsb = 4000,
 123                 .power_lsb_factor = 20,
 124         },
 125         [ina226] = {
 126                 .config_default = INA226_CONFIG_DEFAULT,
 127                 .calibration_value = 2048,
 128                 .registers = INA226_REGISTERS,
 129                 .shunt_div = 400,
 130                 .bus_voltage_shift = 0,
 131                 .bus_voltage_lsb = 1250,
 132                 .power_lsb_factor = 25,
 133         },
 134 };
 135
 136 /*
 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.
 141  */
 142 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
 143
 144 static int ina226_reg_to_interval(u16 config)
 145 {
 146         int avg = ina226_avg_tab[INA226_READ_AVG(config)];
 147
 148         /*
 149          * Multiply the total conversion time by the number of averages.
 150          * Return the result in milliseconds.
 151          */
 152         return DIV_ROUND_CLOSEST(avg * INA226_TOTAL_CONV_TIME_DEFAULT, 1000);
 153 }
 154
 155 /*
 156  * Return the new, shifted AVG field value of CONFIG register,
 157  * to use with regmap_update_bits
 158  */
 159 static u16 ina226_interval_to_reg(int interval)
 160 {
 161         int avg, avg_bits;
 162
 163         avg = DIV_ROUND_CLOSEST(interval * 1000,
 164                                 INA226_TOTAL_CONV_TIME_DEFAULT);
 165         avg_bits = find_closest(avg, ina226_avg_tab,
 166                                 ARRAY_SIZE(ina226_avg_tab));
 167
 168         return INA226_SHIFT_AVG(avg_bits);
 169 }
 170
 171 /*
 172  * Calibration register is set to the best value, which eliminates
 173  * truncation errors on calculating current register in hardware.
 174  * According to datasheet (eq. 3) the best values are 2048 for
 175  * ina226 and 4096 for ina219. They are hardcoded as calibration_value.
 176  */
 177 static int ina2xx_calibrate(struct ina2xx_data *data)
 178 {
 179         return regmap_write(data->regmap, INA2XX_CALIBRATION,
 180                             data->config->calibration_value);
 181 }
 182
 183 /*
 184  * Initialize the configuration and calibration registers.
 185  */
 186 static int ina2xx_init(struct ina2xx_data *data)
 187 {
 188         int ret = regmap_write(data->regmap, INA2XX_CONFIG,
 189                                data->config->config_default);
 190         if (ret < 0)
 191                 return ret;
 192
 193         return ina2xx_calibrate(data);
 194 }
 195
 196 static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
 197 {
 198         struct ina2xx_data *data = dev_get_drvdata(dev);
 199         int ret, retry;
 200
 201         dev_dbg(dev, "Starting register %d read\n", reg);
 202
 203         for (retry = 5; retry; retry--) {
 204
 205                 ret = regmap_read(data->regmap, reg, regval);
 206                 if (ret < 0)
 207                         return ret;
 208
 209                 dev_dbg(dev, "read %d, val = 0x%04x\n", reg, *regval);
 210
 211                 /*
 212                  * If the current value in the calibration register is 0, the
 213                  * power and current registers will also remain at 0. In case
 214                  * the chip has been reset let's check the calibration
 215                  * register and reinitialize if needed.
 216                  * We do that extra read of the calibration register if there
 217                  * is some hint of a chip reset.
 218                  */
 219                 if (*regval == 0) {
 220                         unsigned int cal;
 221
 222                         ret = regmap_read(data->regmap, INA2XX_CALIBRATION,
 223                                           &cal);
 224                         if (ret < 0)
 225                                 return ret;
 226
 227                         if (cal == 0) {
 228                                 dev_warn(dev, "chip not calibrated, reinitializing\n");
 229
 230                                 ret = ina2xx_init(data);
 231                                 if (ret < 0)
 232                                         return ret;
 233                                 /*
 234                                  * Let's make sure the power and current
 235                                  * registers have been updated before trying
 236                                  * again.
 237                                  */
 238                                 msleep(INA2XX_MAX_DELAY);
 239                                 continue;
 240                         }
 241                 }
 242                 return 0;
 243         }
 244
 245         /*
 246          * If we're here then although all write operations succeeded, the
 247          * chip still returns 0 in the calibration register. Nothing more we
 248          * can do here.
 249          */
 250         dev_err(dev, "unable to reinitialize the chip\n");
 251         return -ENODEV;
 252 }
 253
 254 static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
 255                             unsigned int regval)
 256 {
 257         int val;
 258
 259         switch (reg) {
 260         case INA2XX_SHUNT_VOLTAGE:
 261                 /* signed register */
 262                 val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div);
 263                 break;
 264         case INA2XX_BUS_VOLTAGE:
 265                 val = (regval >> data->config->bus_voltage_shift)
 266                   * data->config->bus_voltage_lsb;
 267                 val = DIV_ROUND_CLOSEST(val, 1000);
 268                 break;
 269         case INA2XX_POWER:
 270                 val = regval * data->power_lsb_uW;
 271                 break;
 272         case INA2XX_CURRENT:
 273                 /* signed register, result in mA */
 274                 val = (s16)regval * data->current_lsb_uA;
 275                 val = DIV_ROUND_CLOSEST(val, 1000);
 276                 break;
 277         case INA2XX_CALIBRATION:
 278                 val = regval;
 279                 break;
 280         default:
 281                 /* programmer goofed */
 282                 WARN_ON_ONCE(1);
 283                 val = 0;
 284                 break;
 285         }
 286
 287         return val;
 288 }
 289
 290 static ssize_t ina2xx_value_show(struct device *dev,
 291                                  struct device_attribute *da, char *buf)
 292 {
 293         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 294         struct ina2xx_data *data = dev_get_drvdata(dev);
 295         unsigned int regval;
 296
 297         int err = ina2xx_read_reg(dev, attr->index, &regval);
 298
 299         if (err < 0)
 300                 return err;
 301
 302         return snprintf(buf, PAGE_SIZE, "%d\n",
 303                         ina2xx_get_value(data, attr->index, regval));
 304 }
 305
 306 /*
 307  * In order to keep calibration register value fixed, the product
 308  * of current_lsb and shunt_resistor should also be fixed and equal
 309  * to shunt_voltage_lsb = 1 / shunt_div multiplied by 10^9 in order
 310  * to keep the scale.
 311  */
 312 static int ina2xx_set_shunt(struct ina2xx_data *data, long val)
 313 {
 314         unsigned int dividend = DIV_ROUND_CLOSEST(1000000000,
 315                                                   data->config->shunt_div);
 316         if (val <= 0 || val > dividend)
 317                 return -EINVAL;
 318
 319         mutex_lock(&data->config_lock);
 320         data->rshunt = val;
 321         data->current_lsb_uA = DIV_ROUND_CLOSEST(dividend, val);
 322         data->power_lsb_uW = data->config->power_lsb_factor *
 323                              data->current_lsb_uA;
 324         mutex_unlock(&data->config_lock);
 325
 326         return 0;
 327 }
 328
 329 static ssize_t ina2xx_shunt_show(struct device *dev,
 330                                  struct device_attribute *da, char *buf)
 331 {
 332         struct ina2xx_data *data = dev_get_drvdata(dev);
 333
 334         return snprintf(buf, PAGE_SIZE, "%li\n", data->rshunt);
 335 }
 336
 337 static ssize_t ina2xx_shunt_store(struct device *dev,
 338                                   struct device_attribute *da,
 339                                   const char *buf, size_t count)
 340 {
 341         unsigned long val;
 342         int status;
 343         struct ina2xx_data *data = dev_get_drvdata(dev);
 344
 345         status = kstrtoul(buf, 10, &val);
 346         if (status < 0)
 347                 return status;
 348
 349         status = ina2xx_set_shunt(data, val);
 350         if (status < 0)
 351                 return status;
 352         return count;
 353 }
 354
 355 static ssize_t ina226_interval_store(struct device *dev,
 356                                      struct device_attribute *da,
 357                                      const char *buf, size_t count)
 358 {
 359         struct ina2xx_data *data = dev_get_drvdata(dev);
 360         unsigned long val;
 361         int status;
 362
 363         status = kstrtoul(buf, 10, &val);
 364         if (status < 0)
 365                 return status;
 366
 367         if (val > INT_MAX || val == 0)
 368                 return -EINVAL;
 369
 370         status = regmap_update_bits(data->regmap, INA2XX_CONFIG,
 371                                     INA226_AVG_RD_MASK,
 372                                     ina226_interval_to_reg(val));
 373         if (status < 0)
 374                 return status;
 375
 376         return count;
 377 }
 378
 379 static ssize_t ina226_interval_show(struct device *dev,
 380                                     struct device_attribute *da, char *buf)
 381 {
 382         struct ina2xx_data *data = dev_get_drvdata(dev);
 383         int status;
 384         unsigned int regval;
 385
 386         status = regmap_read(data->regmap, INA2XX_CONFIG, &regval);
 387         if (status)
 388                 return status;
 389
 390         return snprintf(buf, PAGE_SIZE, "%d\n", ina226_reg_to_interval(regval));
 391 }
 392
 393 /* shunt voltage */
 394 static SENSOR_DEVICE_ATTR_RO(in0_input, ina2xx_value, INA2XX_SHUNT_VOLTAGE);
 395
 396 /* bus voltage */
 397 static SENSOR_DEVICE_ATTR_RO(in1_input, ina2xx_value, INA2XX_BUS_VOLTAGE);
 398
 399 /* calculated current */
 400 static SENSOR_DEVICE_ATTR_RO(curr1_input, ina2xx_value, INA2XX_CURRENT);
 401
 402 /* calculated power */
 403 static SENSOR_DEVICE_ATTR_RO(power1_input, ina2xx_value, INA2XX_POWER);
 404
 405 /* shunt resistance */
 406 static SENSOR_DEVICE_ATTR_RW(shunt_resistor, ina2xx_shunt, INA2XX_CALIBRATION);
 407
 408 /* update interval (ina226 only) */
 409 static SENSOR_DEVICE_ATTR_RW(update_interval, ina226_interval, 0);
 410
 411 /* pointers to created device attributes */
 412 static struct attribute *ina2xx_attrs[] = {
 413         &sensor_dev_attr_in0_input.dev_attr.attr,
 414         &sensor_dev_attr_in1_input.dev_attr.attr,
 415         &sensor_dev_attr_curr1_input.dev_attr.attr,
 416         &sensor_dev_attr_power1_input.dev_attr.attr,
 417         &sensor_dev_attr_shunt_resistor.dev_attr.attr,
 418         NULL,
 419 };
 420
 421 static const struct attribute_group ina2xx_group = {
 422         .attrs = ina2xx_attrs,
 423 };
 424
 425 static struct attribute *ina226_attrs[] = {
 426         &sensor_dev_attr_update_interval.dev_attr.attr,
 427         NULL,
 428 };
 429
 430 static const struct attribute_group ina226_group = {
 431         .attrs = ina226_attrs,
 432 };
 433
 434 static int ina2xx_probe(struct i2c_client *client,
 435                         const struct i2c_device_id *id)
 436 {
 437         struct device *dev = &client->dev;
 438         struct ina2xx_data *data;
 439         struct device *hwmon_dev;
 440         u32 val;
 441         int ret, group = 0;
 442         enum ina2xx_ids chip;
 443
 444         if (client->dev.of_node)
 445                 chip = (enum ina2xx_ids)of_device_get_match_data(&client->dev);
 446         else
 447                 chip = id->driver_data;
 448
 449         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 450         if (!data)
 451                 return -ENOMEM;
 452
 453         /* set the device type */
 454         data->config = &ina2xx_config[chip];
 455         mutex_init(&data->config_lock);
 456
 457         if (of_property_read_u32(dev->of_node, "shunt-resistor", &val) < 0) {
 458                 struct ina2xx_platform_data *pdata = dev_get_platdata(dev);
 459
 460                 if (pdata)
 461                         val = pdata->shunt_uohms;
 462                 else
 463                         val = INA2XX_RSHUNT_DEFAULT;
 464         }
 465
 466         ina2xx_set_shunt(data, val);
 467
 468         ina2xx_regmap_config.max_register = data->config->registers;
 469
 470         data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
 471         if (IS_ERR(data->regmap)) {
 472                 dev_err(dev, "failed to allocate register map\n");
 473                 return PTR_ERR(data->regmap);
 474         }
 475
 476         ret = ina2xx_init(data);
 477         if (ret < 0) {
 478                 dev_err(dev, "error configuring the device: %d\n", ret);
 479                 return -ENODEV;
 480         }
 481
 482         data->groups[group++] = &ina2xx_group;
 483         if (chip == ina226)
 484                 data->groups[group++] = &ina226_group;
 485
 486         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 487                                                            data, data->groups);
 488         if (IS_ERR(hwmon_dev))
 489                 return PTR_ERR(hwmon_dev);
 490
 491         dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n",
 492                  client->name, data->rshunt);
 493
 494         return 0;
 495 }
 496
 497 static const struct i2c_device_id ina2xx_id[] = {
 498         { "ina219", ina219 },
 499         { "ina220", ina219 },
 500         { "ina226", ina226 },
 501         { "ina230", ina226 },
 502         { "ina231", ina226 },
 503         { }
 504 };
 505 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
 506
 507 static const struct of_device_id __maybe_unused ina2xx_of_match[] = {
 508         {
 509                 .compatible = "ti,ina219",
 510                 .data = (void *)ina219
 511         },
 512         {
 513                 .compatible = "ti,ina220",
 514                 .data = (void *)ina219
 515         },
 516         {
 517                 .compatible = "ti,ina226",
 518                 .data = (void *)ina226
 519         },
 520         {
 521                 .compatible = "ti,ina230",
 522                 .data = (void *)ina226
 523         },
 524         {
 525                 .compatible = "ti,ina231",
 526                 .data = (void *)ina226
 527         },
 528         { },
 529 };
 530 MODULE_DEVICE_TABLE(of, ina2xx_of_match);
 531
 532 static struct i2c_driver ina2xx_driver = {
 533         .driver = {
 534                 .name   = "ina2xx",
 535                 .of_match_table = of_match_ptr(ina2xx_of_match),
 536         },
 537         .probe          = ina2xx_probe,
 538         .id_table       = ina2xx_id,
 539 };
 540
 541 module_i2c_driver(ina2xx_driver);
 542
 543 MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
 544 MODULE_DESCRIPTION("ina2xx driver");
 545 MODULE_LICENSE("GPL");