drivers/iio/adc/ina2xx-adc.c

   1 /*
   2  * INA2XX Current and Power Monitors
   3  *
   4  * Copyright 2015 Baylibre SAS.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * Based on linux/drivers/iio/adc/ad7291.c
  11  * Copyright 2010-2011 Analog Devices Inc.
  12  *
  13  * Based on linux/drivers/hwmon/ina2xx.c
  14  * Copyright 2012 Lothar Felten <l-felten@ti.com>
  15  *
  16  * Licensed under the GPL-2 or later.
  17  *
  18  * IIO driver for INA219-220-226-230-231
  19  *
  20  * Configurable 7-bit I2C slave address from 0x40 to 0x4F
  21  */
  22
  23 #include <linux/delay.h>
  24 #include <linux/i2c.h>
  25 #include <linux/iio/kfifo_buf.h>
  26 #include <linux/iio/sysfs.h>
  27 #include <linux/kthread.h>
  28 #include <linux/module.h>
  29 #include <linux/regmap.h>
  30 #include <linux/util_macros.h>
  31
  32 #include <linux/platform_data/ina2xx.h>
  33
  34 /* INA2XX registers definition */
  35 #define INA2XX_CONFIG                   0x00
  36 #define INA2XX_SHUNT_VOLTAGE            0x01    /* readonly */
  37 #define INA2XX_BUS_VOLTAGE              0x02    /* readonly */
  38 #define INA2XX_POWER                    0x03    /* readonly */
  39 #define INA2XX_CURRENT                  0x04    /* readonly */
  40 #define INA2XX_CALIBRATION              0x05
  41
  42 #define INA226_ALERT_MASK               GENMASK(2, 1)
  43 #define INA266_CVRF                     BIT(3)
  44
  45 #define INA2XX_MAX_REGISTERS            8
  46
  47 /* settings - depend on use case */
  48 #define INA219_CONFIG_DEFAULT           0x399F  /* PGA=8 */
  49 #define INA226_CONFIG_DEFAULT           0x4327
  50 #define INA226_DEFAULT_AVG              4
  51 #define INA226_DEFAULT_IT               1110
  52
  53 #define INA2XX_RSHUNT_DEFAULT           10000
  54
  55 /*
  56  * bit mask for reading the averaging setting in the configuration register
  57  * FIXME: use regmap_fields.
  58  */
  59 #define INA2XX_MODE_MASK        GENMASK(3, 0)
  60
  61 #define INA226_AVG_MASK         GENMASK(11, 9)
  62 #define INA226_SHIFT_AVG(val)   ((val) << 9)
  63
  64 /* Integration time for VBus */
  65 #define INA226_ITB_MASK         GENMASK(8, 6)
  66 #define INA226_SHIFT_ITB(val)   ((val) << 6)
  67
  68 /* Integration time for VShunt */
  69 #define INA226_ITS_MASK         GENMASK(5, 3)
  70 #define INA226_SHIFT_ITS(val)   ((val) << 3)
  71
  72 /* Cosmetic macro giving the sampling period for a full P=UxI cycle */
  73 #define SAMPLING_PERIOD(c)      ((c->int_time_vbus + c->int_time_vshunt) \
  74                                  * c->avg)
  75
  76 static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg)
  77 {
  78         return (reg == INA2XX_CONFIG) || (reg > INA2XX_CURRENT);
  79 }
  80
  81 static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg)
  82 {
  83         return (reg != INA2XX_CONFIG);
  84 }
  85
  86 static inline bool is_signed_reg(unsigned int reg)
  87 {
  88         return (reg == INA2XX_SHUNT_VOLTAGE) || (reg == INA2XX_CURRENT);
  89 }
  90
  91 static const struct regmap_config ina2xx_regmap_config = {
  92         .reg_bits = 8,
  93         .val_bits = 16,
  94         .max_register = INA2XX_MAX_REGISTERS,
  95         .writeable_reg = ina2xx_is_writeable_reg,
  96         .volatile_reg = ina2xx_is_volatile_reg,
  97 };
  98
  99 enum ina2xx_ids { ina219, ina226 };
 100
 101 struct ina2xx_config {
 102         u16 config_default;
 103         int calibration_factor;
 104         int shunt_div;
 105         int bus_voltage_shift;
 106         int bus_voltage_lsb;    /* uV */
 107         int power_lsb;          /* uW */
 108 };
 109
 110 struct ina2xx_chip_info {
 111         struct regmap *regmap;
 112         struct task_struct *task;
 113         const struct ina2xx_config *config;
 114         struct mutex state_lock;
 115         unsigned int shunt_resistor;
 116         int avg;
 117         int int_time_vbus; /* Bus voltage integration time uS */
 118         int int_time_vshunt; /* Shunt voltage integration time uS */
 119         bool allow_async_readout;
 120 };
 121
 122 static const struct ina2xx_config ina2xx_config[] = {
 123         [ina219] = {
 124                 .config_default = INA219_CONFIG_DEFAULT,
 125                 .calibration_factor = 40960000,
 126                 .shunt_div = 100,
 127                 .bus_voltage_shift = 3,
 128                 .bus_voltage_lsb = 4000,
 129                 .power_lsb = 20000,
 130         },
 131         [ina226] = {
 132                 .config_default = INA226_CONFIG_DEFAULT,
 133                 .calibration_factor = 5120000,
 134                 .shunt_div = 400,
 135                 .bus_voltage_shift = 0,
 136                 .bus_voltage_lsb = 1250,
 137                 .power_lsb = 25000,
 138         },
 139 };
 140
 141 static int ina2xx_read_raw(struct iio_dev *indio_dev,
 142                            struct iio_chan_spec const *chan,
 143                            int *val, int *val2, long mask)
 144 {
 145         int ret;
 146         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 147         unsigned int regval;
 148
 149         switch (mask) {
 150         case IIO_CHAN_INFO_RAW:
 151                 ret = regmap_read(chip->regmap, chan->address, &regval);
 152                 if (ret)
 153                         return ret;
 154
 155                 if (is_signed_reg(chan->address))
 156                         *val = (s16) regval;
 157                 else
 158                         *val  = regval;
 159
 160                 return IIO_VAL_INT;
 161
 162         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 163                 *val = chip->avg;
 164                 return IIO_VAL_INT;
 165
 166         case IIO_CHAN_INFO_INT_TIME:
 167                 *val = 0;
 168                 if (chan->address == INA2XX_SHUNT_VOLTAGE)
 169                         *val2 = chip->int_time_vshunt;
 170                 else
 171                         *val2 = chip->int_time_vbus;
 172
 173                 return IIO_VAL_INT_PLUS_MICRO;
 174
 175         case IIO_CHAN_INFO_SAMP_FREQ:
 176                 /*
 177                  * Sample freq is read only, it is a consequence of
 178                  * 1/AVG*(CT_bus+CT_shunt).
 179                  */
 180                 *val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip));
 181
 182                 return IIO_VAL_INT;
 183
 184         case IIO_CHAN_INFO_SCALE:
 185                 switch (chan->address) {
 186                 case INA2XX_SHUNT_VOLTAGE:
 187                         /* processed (mV) = raw/shunt_div */
 188                         *val2 = chip->config->shunt_div;
 189                         *val = 1;
 190                         return IIO_VAL_FRACTIONAL;
 191
 192                 case INA2XX_BUS_VOLTAGE:
 193                         /* processed (mV) = raw*lsb (uV) / (1000 << shift) */
 194                         *val = chip->config->bus_voltage_lsb;
 195                         *val2 = 1000 << chip->config->bus_voltage_shift;
 196                         return IIO_VAL_FRACTIONAL;
 197
 198                 case INA2XX_POWER:
 199                         /* processed (mW) = raw*lsb (uW) / 1000 */
 200                         *val = chip->config->power_lsb;
 201                         *val2 = 1000;
 202                         return IIO_VAL_FRACTIONAL;
 203
 204                 case INA2XX_CURRENT:
 205                         /* processed (mA) = raw (mA) */
 206                         *val = 1;
 207                         return IIO_VAL_INT;
 208                 }
 209         }
 210
 211         return -EINVAL;
 212 }
 213
 214 /*
 215  * Available averaging rates for ina226. The indices correspond with
 216  * the bit values expected by the chip (according to the ina226 datasheet,
 217  * table 3 AVG bit settings, found at
 218  * http://www.ti.com/lit/ds/symlink/ina226.pdf.
 219  */
 220 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
 221
 222 static int ina226_set_average(struct ina2xx_chip_info *chip, unsigned int val,
 223                               unsigned int *config)
 224 {
 225         int bits;
 226
 227         if (val > 1024 || val < 1)
 228                 return -EINVAL;
 229
 230         bits = find_closest(val, ina226_avg_tab,
 231                             ARRAY_SIZE(ina226_avg_tab));
 232
 233         chip->avg = ina226_avg_tab[bits];
 234
 235         *config &= ~INA226_AVG_MASK;
 236         *config |= INA226_SHIFT_AVG(bits) & INA226_AVG_MASK;
 237
 238         return 0;
 239 }
 240
 241 /* Conversion times in uS */
 242 static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100,
 243                                             2116, 4156, 8244 };
 244
 245 static int ina226_set_int_time_vbus(struct ina2xx_chip_info *chip,
 246                                     unsigned int val_us, unsigned int *config)
 247 {
 248         int bits;
 249
 250         if (val_us > 8244 || val_us < 140)
 251                 return -EINVAL;
 252
 253         bits = find_closest(val_us, ina226_conv_time_tab,
 254                             ARRAY_SIZE(ina226_conv_time_tab));
 255
 256         chip->int_time_vbus = ina226_conv_time_tab[bits];
 257
 258         *config &= ~INA226_ITB_MASK;
 259         *config |= INA226_SHIFT_ITB(bits) & INA226_ITB_MASK;
 260
 261         return 0;
 262 }
 263
 264 static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip,
 265                                       unsigned int val_us, unsigned int *config)
 266 {
 267         int bits;
 268
 269         if (val_us > 8244 || val_us < 140)
 270                 return -EINVAL;
 271
 272         bits = find_closest(val_us, ina226_conv_time_tab,
 273                             ARRAY_SIZE(ina226_conv_time_tab));
 274
 275         chip->int_time_vshunt = ina226_conv_time_tab[bits];
 276
 277         *config &= ~INA226_ITS_MASK;
 278         *config |= INA226_SHIFT_ITS(bits) & INA226_ITS_MASK;
 279
 280         return 0;
 281 }
 282
 283 static int ina2xx_write_raw(struct iio_dev *indio_dev,
 284                             struct iio_chan_spec const *chan,
 285                             int val, int val2, long mask)
 286 {
 287         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 288         unsigned int config, tmp;
 289         int ret;
 290
 291         if (iio_buffer_enabled(indio_dev))
 292                 return -EBUSY;
 293
 294         mutex_lock(&chip->state_lock);
 295
 296         ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
 297         if (ret)
 298                 goto err;
 299
 300         tmp = config;
 301
 302         switch (mask) {
 303         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 304                 ret = ina226_set_average(chip, val, &tmp);
 305                 break;
 306
 307         case IIO_CHAN_INFO_INT_TIME:
 308                 if (chan->address == INA2XX_SHUNT_VOLTAGE)
 309                         ret = ina226_set_int_time_vshunt(chip, val2, &tmp);
 310                 else
 311                         ret = ina226_set_int_time_vbus(chip, val2, &tmp);
 312                 break;
 313
 314         default:
 315                 ret = -EINVAL;
 316         }
 317
 318         if (!ret && (tmp != config))
 319                 ret = regmap_write(chip->regmap, INA2XX_CONFIG, tmp);
 320 err:
 321         mutex_unlock(&chip->state_lock);
 322
 323         return ret;
 324 }
 325
 326 static ssize_t ina2xx_allow_async_readout_show(struct device *dev,
 327                                            struct device_attribute *attr,
 328                                            char *buf)
 329 {
 330         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 331
 332         return sprintf(buf, "%d\n", chip->allow_async_readout);
 333 }
 334
 335 static ssize_t ina2xx_allow_async_readout_store(struct device *dev,
 336                                 struct device_attribute *attr,
 337                                 const char *buf, size_t len)
 338 {
 339         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 340         bool val;
 341         int ret;
 342
 343         ret = strtobool((const char *) buf, &val);
 344         if (ret)
 345                 return ret;
 346
 347         chip->allow_async_readout = val;
 348
 349         return len;
 350 }
 351
 352 /*
 353  * Set current LSB to 1mA, shunt is in uOhms
 354  * (equation 13 in datasheet). We hardcode a Current_LSB
 355  * of 1.0 x10-6. The only remaining parameter is RShunt.
 356  * There is no need to expose the CALIBRATION register
 357  * to the user for now. But we need to reset this register
 358  * if the user updates RShunt after driver init, e.g upon
 359  * reading an EEPROM/Probe-type value.
 360  */
 361 static int ina2xx_set_calibration(struct ina2xx_chip_info *chip)
 362 {
 363         u16 regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor,
 364                                    chip->shunt_resistor);
 365
 366         return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval);
 367 }
 368
 369 static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val)
 370 {
 371         if (val <= 0 || val > chip->config->calibration_factor)
 372                 return -EINVAL;
 373
 374         chip->shunt_resistor = val;
 375
 376         return 0;
 377 }
 378
 379 static ssize_t ina2xx_shunt_resistor_show(struct device *dev,
 380                                           struct device_attribute *attr,
 381                                           char *buf)
 382 {
 383         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 384
 385         return sprintf(buf, "%d\n", chip->shunt_resistor);
 386 }
 387
 388 static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
 389                                            struct device_attribute *attr,
 390                                            const char *buf, size_t len)
 391 {
 392         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 393         unsigned long val;
 394         int ret;
 395
 396         ret = kstrtoul((const char *) buf, 10, &val);
 397         if (ret)
 398                 return ret;
 399
 400         ret = set_shunt_resistor(chip, val);
 401         if (ret)
 402                 return ret;
 403
 404         /* Update the Calibration register */
 405         ret = ina2xx_set_calibration(chip);
 406         if (ret)
 407                 return ret;
 408
 409         return len;
 410 }
 411
 412 #define INA2XX_CHAN(_type, _index, _address) { \
 413         .type = (_type), \
 414         .address = (_address), \
 415         .indexed = 1, \
 416         .channel = (_index), \
 417         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \
 418         | BIT(IIO_CHAN_INFO_SCALE), \
 419         .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
 420                                    BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
 421         .scan_index = (_index), \
 422         .scan_type = { \
 423                 .sign = 'u', \
 424                 .realbits = 16, \
 425                 .storagebits = 16, \
 426                 .endianness = IIO_CPU, \
 427         } \
 428 }
 429
 430 /*
 431  * Sampling Freq is a consequence of the integration times of
 432  * the Voltage channels.
 433  */
 434 #define INA2XX_CHAN_VOLTAGE(_index, _address) { \
 435         .type = IIO_VOLTAGE, \
 436         .address = (_address), \
 437         .indexed = 1, \
 438         .channel = (_index), \
 439         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 440                               BIT(IIO_CHAN_INFO_SCALE) | \
 441                               BIT(IIO_CHAN_INFO_INT_TIME), \
 442         .scan_index = (_index), \
 443         .scan_type = { \
 444                 .sign = 'u', \
 445                 .realbits = 16, \
 446                 .storagebits = 16, \
 447                 .endianness = IIO_LE, \
 448         } \
 449 }
 450
 451 static const struct iio_chan_spec ina2xx_channels[] = {
 452         INA2XX_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
 453         INA2XX_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
 454         INA2XX_CHAN(IIO_POWER, 2, INA2XX_POWER),
 455         INA2XX_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
 456         IIO_CHAN_SOFT_TIMESTAMP(4),
 457 };
 458
 459 static int ina2xx_work_buffer(struct iio_dev *indio_dev)
 460 {
 461         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 462         unsigned short data[8];
 463         int bit, ret, i = 0;
 464         s64 time_a, time_b;
 465         unsigned int alert;
 466
 467         time_a = iio_get_time_ns(indio_dev);
 468
 469         /*
 470          * Because the timer thread and the chip conversion clock
 471          * are asynchronous, the period difference will eventually
 472          * result in reading V[k-1] again, or skip V[k] at time Tk.
 473          * In order to resync the timer with the conversion process
 474          * we check the ConVersionReadyFlag.
 475          * On hardware that supports using the ALERT pin to toggle a
 476          * GPIO a triggered buffer could be used instead.
 477          * For now, we pay for that extra read of the ALERT register
 478          */
 479         if (!chip->allow_async_readout)
 480                 do {
 481                         ret = regmap_read(chip->regmap, INA226_ALERT_MASK,
 482                                           &alert);
 483                         if (ret < 0)
 484                                 return ret;
 485
 486                         alert &= INA266_CVRF;
 487                 } while (!alert);
 488
 489         /*
 490          * Single register reads: bulk_read will not work with ina226
 491          * as there is no auto-increment of the address register for
 492          * data length longer than 16bits.
 493          */
 494         for_each_set_bit(bit, indio_dev->active_scan_mask,
 495                          indio_dev->masklength) {
 496                 unsigned int val;
 497
 498                 ret = regmap_read(chip->regmap,
 499                                   INA2XX_SHUNT_VOLTAGE + bit, &val);
 500                 if (ret < 0)
 501                         return ret;
 502
 503                 data[i++] = val;
 504         }
 505
 506         time_b = iio_get_time_ns(indio_dev);
 507
 508         iio_push_to_buffers_with_timestamp(indio_dev,
 509                                            (unsigned int *)data, time_a);
 510
 511         return (unsigned long)(time_b - time_a) / 1000;
 512 };
 513
 514 static int ina2xx_capture_thread(void *data)
 515 {
 516         struct iio_dev *indio_dev = data;
 517         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 518         unsigned int sampling_us = SAMPLING_PERIOD(chip);
 519         int buffer_us;
 520
 521         /*
 522          * Poll a bit faster than the chip internal Fs, in case
 523          * we wish to sync with the conversion ready flag.
 524          */
 525         if (!chip->allow_async_readout)
 526                 sampling_us -= 200;
 527
 528         do {
 529                 buffer_us = ina2xx_work_buffer(indio_dev);
 530                 if (buffer_us < 0)
 531                         return buffer_us;
 532
 533                 if (sampling_us > buffer_us)
 534                         udelay(sampling_us - buffer_us);
 535
 536         } while (!kthread_should_stop());
 537
 538         return 0;
 539 }
 540
 541 static int ina2xx_buffer_enable(struct iio_dev *indio_dev)
 542 {
 543         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 544         unsigned int sampling_us = SAMPLING_PERIOD(chip);
 545
 546         dev_dbg(&indio_dev->dev, "Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n",
 547                 (unsigned int)(*indio_dev->active_scan_mask),
 548                 1000000 / sampling_us, chip->avg);
 549
 550         dev_dbg(&indio_dev->dev, "Expected work period: %u us\n", sampling_us);
 551         dev_dbg(&indio_dev->dev, "Async readout mode: %d\n",
 552                 chip->allow_async_readout);
 553
 554         chip->task = kthread_run(ina2xx_capture_thread, (void *)indio_dev,
 555                                  "%s:%d-%uus", indio_dev->name, indio_dev->id,
 556                                  sampling_us);
 557
 558         return PTR_ERR_OR_ZERO(chip->task);
 559 }
 560
 561 static int ina2xx_buffer_disable(struct iio_dev *indio_dev)
 562 {
 563         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 564
 565         if (chip->task) {
 566                 kthread_stop(chip->task);
 567                 chip->task = NULL;
 568         }
 569
 570         return 0;
 571 }
 572
 573 static const struct iio_buffer_setup_ops ina2xx_setup_ops = {
 574         .postenable = &ina2xx_buffer_enable,
 575         .predisable = &ina2xx_buffer_disable,
 576 };
 577
 578 static int ina2xx_debug_reg(struct iio_dev *indio_dev,
 579                             unsigned reg, unsigned writeval, unsigned *readval)
 580 {
 581         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 582
 583         if (!readval)
 584                 return regmap_write(chip->regmap, reg, writeval);
 585
 586         return regmap_read(chip->regmap, reg, readval);
 587 }
 588
 589 /* Possible integration times for vshunt and vbus */
 590 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");
 591
 592 static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR,
 593                        ina2xx_allow_async_readout_show,
 594                        ina2xx_allow_async_readout_store, 0);
 595
 596 static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR,
 597                        ina2xx_shunt_resistor_show,
 598                        ina2xx_shunt_resistor_store, 0);
 599
 600 static struct attribute *ina2xx_attributes[] = {
 601         &iio_dev_attr_in_allow_async_readout.dev_attr.attr,
 602         &iio_const_attr_integration_time_available.dev_attr.attr,
 603         &iio_dev_attr_in_shunt_resistor.dev_attr.attr,
 604         NULL,
 605 };
 606
 607 static const struct attribute_group ina2xx_attribute_group = {
 608         .attrs = ina2xx_attributes,
 609 };
 610
 611 static const struct iio_info ina2xx_info = {
 612         .driver_module = THIS_MODULE,
 613         .attrs = &ina2xx_attribute_group,
 614         .read_raw = ina2xx_read_raw,
 615         .write_raw = ina2xx_write_raw,
 616         .debugfs_reg_access = ina2xx_debug_reg,
 617 };
 618
 619 /* Initialize the configuration and calibration registers. */
 620 static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
 621 {
 622         int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config);
 623         if (ret)
 624                 return ret;
 625
 626         return ina2xx_set_calibration(chip);
 627 }
 628
 629 static int ina2xx_probe(struct i2c_client *client,
 630                         const struct i2c_device_id *id)
 631 {
 632         struct ina2xx_chip_info *chip;
 633         struct iio_dev *indio_dev;
 634         struct iio_buffer *buffer;
 635         unsigned int val;
 636         int ret;
 637
 638         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
 639         if (!indio_dev)
 640                 return -ENOMEM;
 641
 642         chip = iio_priv(indio_dev);
 643
 644         /* This is only used for device removal purposes. */
 645         i2c_set_clientdata(client, indio_dev);
 646
 647         chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
 648         if (IS_ERR(chip->regmap)) {
 649                 dev_err(&client->dev, "failed to allocate register map\n");
 650                 return PTR_ERR(chip->regmap);
 651         }
 652
 653         chip->config = &ina2xx_config[id->driver_data];
 654
 655         mutex_init(&chip->state_lock);
 656
 657         if (of_property_read_u32(client->dev.of_node,
 658                                  "shunt-resistor", &val) < 0) {
 659                 struct ina2xx_platform_data *pdata =
 660                     dev_get_platdata(&client->dev);
 661
 662                 if (pdata)
 663                         val = pdata->shunt_uohms;
 664                 else
 665                         val = INA2XX_RSHUNT_DEFAULT;
 666         }
 667
 668         ret = set_shunt_resistor(chip, val);
 669         if (ret)
 670                 return ret;
 671
 672         /* Patch the current config register with default. */
 673         val = chip->config->config_default;
 674
 675         if (id->driver_data == ina226) {
 676                 ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
 677                 ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
 678                 ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
 679         }
 680
 681         ret = ina2xx_init(chip, val);
 682         if (ret) {
 683                 dev_err(&client->dev, "error configuring the device\n");
 684                 return ret;
 685         }
 686
 687         indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
 688         indio_dev->dev.parent = &client->dev;
 689         indio_dev->dev.of_node = client->dev.of_node;
 690         indio_dev->channels = ina2xx_channels;
 691         indio_dev->num_channels = ARRAY_SIZE(ina2xx_channels);
 692         indio_dev->name = id->name;
 693         indio_dev->info = &ina2xx_info;
 694         indio_dev->setup_ops = &ina2xx_setup_ops;
 695
 696         buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
 697         if (!buffer)
 698                 return -ENOMEM;
 699
 700         iio_device_attach_buffer(indio_dev, buffer);
 701
 702         return iio_device_register(indio_dev);
 703 }
 704
 705 static int ina2xx_remove(struct i2c_client *client)
 706 {
 707         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 708         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 709
 710         iio_device_unregister(indio_dev);
 711
 712         /* Powerdown */
 713         return regmap_update_bits(chip->regmap, INA2XX_CONFIG,
 714                                   INA2XX_MODE_MASK, 0);
 715 }
 716
 717 static const struct i2c_device_id ina2xx_id[] = {
 718         {"ina219", ina219},
 719         {"ina220", ina219},
 720         {"ina226", ina226},
 721         {"ina230", ina226},
 722         {"ina231", ina226},
 723         {}
 724 };
 725 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
 726
 727 static struct i2c_driver ina2xx_driver = {
 728         .driver = {
 729                    .name = KBUILD_MODNAME,
 730         },
 731         .probe = ina2xx_probe,
 732         .remove = ina2xx_remove,
 733         .id_table = ina2xx_id,
 734 };
 735 module_i2c_driver(ina2xx_driver);
 736
 737 MODULE_AUTHOR("Marc Titinger <marc.titinger@baylibre.com>");
 738 MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver");
 739 MODULE_LICENSE("GPL v2");