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/iio.h>
  26 #include <linux/iio/buffer.h>
  27 #include <linux/iio/kfifo_buf.h>
  28 #include <linux/iio/sysfs.h>
  29 #include <linux/kthread.h>
  30 #include <linux/module.h>
  31 #include <linux/of_device.h>
  32 #include <linux/regmap.h>
  33 #include <linux/util_macros.h>
  34
  35 #include <linux/platform_data/ina2xx.h>
  36
  37 /* INA2XX registers definition */
  38 #define INA2XX_CONFIG                   0x00
  39 #define INA2XX_SHUNT_VOLTAGE            0x01    /* readonly */
  40 #define INA2XX_BUS_VOLTAGE              0x02    /* readonly */
  41 #define INA2XX_POWER                    0x03    /* readonly */
  42 #define INA2XX_CURRENT                  0x04    /* readonly */
  43 #define INA2XX_CALIBRATION              0x05
  44
  45 #define INA226_MASK_ENABLE              0x06
  46 #define INA226_CVRF                     BIT(3)
  47 #define INA219_CNVR                     BIT(1)
  48
  49 #define INA2XX_MAX_REGISTERS            8
  50
  51 /* settings - depend on use case */
  52 #define INA219_CONFIG_DEFAULT           0x399F  /* PGA=8 */
  53 #define INA219_DEFAULT_IT               532
  54 #define INA226_CONFIG_DEFAULT           0x4327
  55 #define INA226_DEFAULT_AVG              4
  56 #define INA226_DEFAULT_IT               1110
  57
  58 #define INA2XX_RSHUNT_DEFAULT           10000
  59
  60 /*
  61  * bit masks for reading the settings in the configuration register
  62  * FIXME: use regmap_fields.
  63  */
  64 #define INA2XX_MODE_MASK        GENMASK(3, 0)
  65
  66 /* Averaging for VBus/VShunt/Power */
  67 #define INA226_AVG_MASK         GENMASK(11, 9)
  68 #define INA226_SHIFT_AVG(val)   ((val) << 9)
  69
  70 /* Integration time for VBus */
  71 #define INA219_ITB_MASK         GENMASK(10, 7)
  72 #define INA219_SHIFT_ITB(val)   ((val) << 7)
  73 #define INA226_ITB_MASK         GENMASK(8, 6)
  74 #define INA226_SHIFT_ITB(val)   ((val) << 6)
  75
  76 /* Integration time for VShunt */
  77 #define INA219_ITS_MASK         GENMASK(6, 3)
  78 #define INA219_SHIFT_ITS(val)   ((val) << 3)
  79 #define INA226_ITS_MASK         GENMASK(5, 3)
  80 #define INA226_SHIFT_ITS(val)   ((val) << 3)
  81
  82 /* Cosmetic macro giving the sampling period for a full P=UxI cycle */
  83 #define SAMPLING_PERIOD(c)      ((c->int_time_vbus + c->int_time_vshunt) \
  84                                  * c->avg)
  85
  86 static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg)
  87 {
  88         return (reg == INA2XX_CONFIG) || (reg > INA2XX_CURRENT);
  89 }
  90
  91 static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg)
  92 {
  93         return (reg != INA2XX_CONFIG);
  94 }
  95
  96 static inline bool is_signed_reg(unsigned int reg)
  97 {
  98         return (reg == INA2XX_SHUNT_VOLTAGE) || (reg == INA2XX_CURRENT);
  99 }
 100
 101 static const struct regmap_config ina2xx_regmap_config = {
 102         .reg_bits = 8,
 103         .val_bits = 16,
 104         .max_register = INA2XX_MAX_REGISTERS,
 105         .writeable_reg = ina2xx_is_writeable_reg,
 106         .volatile_reg = ina2xx_is_volatile_reg,
 107 };
 108
 109 enum ina2xx_ids { ina219, ina226 };
 110
 111 struct ina2xx_config {
 112         u16 config_default;
 113         int calibration_factor;
 114         int shunt_div;
 115         int bus_voltage_shift;
 116         int bus_voltage_lsb;    /* uV */
 117         int power_lsb;          /* uW */
 118         enum ina2xx_ids chip_id;
 119 };
 120
 121 struct ina2xx_chip_info {
 122         struct regmap *regmap;
 123         struct task_struct *task;
 124         const struct ina2xx_config *config;
 125         struct mutex state_lock;
 126         unsigned int shunt_resistor;
 127         int avg;
 128         int int_time_vbus; /* Bus voltage integration time uS */
 129         int int_time_vshunt; /* Shunt voltage integration time uS */
 130         bool allow_async_readout;
 131 };
 132
 133 static const struct ina2xx_config ina2xx_config[] = {
 134         [ina219] = {
 135                 .config_default = INA219_CONFIG_DEFAULT,
 136                 .calibration_factor = 40960000,
 137                 .shunt_div = 100,
 138                 .bus_voltage_shift = 3,
 139                 .bus_voltage_lsb = 4000,
 140                 .power_lsb = 20000,
 141                 .chip_id = ina219,
 142         },
 143         [ina226] = {
 144                 .config_default = INA226_CONFIG_DEFAULT,
 145                 .calibration_factor = 5120000,
 146                 .shunt_div = 400,
 147                 .bus_voltage_shift = 0,
 148                 .bus_voltage_lsb = 1250,
 149                 .power_lsb = 25000,
 150                 .chip_id = ina226,
 151         },
 152 };
 153
 154 static int ina2xx_read_raw(struct iio_dev *indio_dev,
 155                            struct iio_chan_spec const *chan,
 156                            int *val, int *val2, long mask)
 157 {
 158         int ret;
 159         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 160         unsigned int regval;
 161
 162         switch (mask) {
 163         case IIO_CHAN_INFO_RAW:
 164                 ret = regmap_read(chip->regmap, chan->address, &regval);
 165                 if (ret)
 166                         return ret;
 167
 168                 if (is_signed_reg(chan->address))
 169                         *val = (s16) regval;
 170                 else
 171                         *val  = regval;
 172
 173                 return IIO_VAL_INT;
 174
 175         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 176                 *val = chip->avg;
 177                 return IIO_VAL_INT;
 178
 179         case IIO_CHAN_INFO_INT_TIME:
 180                 *val = 0;
 181                 if (chan->address == INA2XX_SHUNT_VOLTAGE)
 182                         *val2 = chip->int_time_vshunt;
 183                 else
 184                         *val2 = chip->int_time_vbus;
 185
 186                 return IIO_VAL_INT_PLUS_MICRO;
 187
 188         case IIO_CHAN_INFO_SAMP_FREQ:
 189                 /*
 190                  * Sample freq is read only, it is a consequence of
 191                  * 1/AVG*(CT_bus+CT_shunt).
 192                  */
 193                 *val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip));
 194
 195                 return IIO_VAL_INT;
 196
 197         case IIO_CHAN_INFO_SCALE:
 198                 switch (chan->address) {
 199                 case INA2XX_SHUNT_VOLTAGE:
 200                         /* processed (mV) = raw/shunt_div */
 201                         *val2 = chip->config->shunt_div;
 202                         *val = 1;
 203                         return IIO_VAL_FRACTIONAL;
 204
 205                 case INA2XX_BUS_VOLTAGE:
 206                         /* processed (mV) = raw*lsb (uV) / (1000 << shift) */
 207                         *val = chip->config->bus_voltage_lsb;
 208                         *val2 = 1000 << chip->config->bus_voltage_shift;
 209                         return IIO_VAL_FRACTIONAL;
 210
 211                 case INA2XX_POWER:
 212                         /* processed (mW) = raw*lsb (uW) / 1000 */
 213                         *val = chip->config->power_lsb;
 214                         *val2 = 1000;
 215                         return IIO_VAL_FRACTIONAL;
 216
 217                 case INA2XX_CURRENT:
 218                         /* processed (mA) = raw (mA) */
 219                         *val = 1;
 220                         return IIO_VAL_INT;
 221                 }
 222         }
 223
 224         return -EINVAL;
 225 }
 226
 227 /*
 228  * Available averaging rates for ina226. The indices correspond with
 229  * the bit values expected by the chip (according to the ina226 datasheet,
 230  * table 3 AVG bit settings, found at
 231  * http://www.ti.com/lit/ds/symlink/ina226.pdf.
 232  */
 233 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
 234
 235 static int ina226_set_average(struct ina2xx_chip_info *chip, unsigned int val,
 236                               unsigned int *config)
 237 {
 238         int bits;
 239
 240         if (val > 1024 || val < 1)
 241                 return -EINVAL;
 242
 243         bits = find_closest(val, ina226_avg_tab,
 244                             ARRAY_SIZE(ina226_avg_tab));
 245
 246         chip->avg = ina226_avg_tab[bits];
 247
 248         *config &= ~INA226_AVG_MASK;
 249         *config |= INA226_SHIFT_AVG(bits) & INA226_AVG_MASK;
 250
 251         return 0;
 252 }
 253
 254 /* Conversion times in uS */
 255 static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100,
 256                                             2116, 4156, 8244 };
 257
 258 static int ina226_set_int_time_vbus(struct ina2xx_chip_info *chip,
 259                                     unsigned int val_us, unsigned int *config)
 260 {
 261         int bits;
 262
 263         if (val_us > 8244 || val_us < 140)
 264                 return -EINVAL;
 265
 266         bits = find_closest(val_us, ina226_conv_time_tab,
 267                             ARRAY_SIZE(ina226_conv_time_tab));
 268
 269         chip->int_time_vbus = ina226_conv_time_tab[bits];
 270
 271         *config &= ~INA226_ITB_MASK;
 272         *config |= INA226_SHIFT_ITB(bits) & INA226_ITB_MASK;
 273
 274         return 0;
 275 }
 276
 277 static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip,
 278                                       unsigned int val_us, unsigned int *config)
 279 {
 280         int bits;
 281
 282         if (val_us > 8244 || val_us < 140)
 283                 return -EINVAL;
 284
 285         bits = find_closest(val_us, ina226_conv_time_tab,
 286                             ARRAY_SIZE(ina226_conv_time_tab));
 287
 288         chip->int_time_vshunt = ina226_conv_time_tab[bits];
 289
 290         *config &= ~INA226_ITS_MASK;
 291         *config |= INA226_SHIFT_ITS(bits) & INA226_ITS_MASK;
 292
 293         return 0;
 294 }
 295
 296 /* Conversion times in uS. */
 297 static const int ina219_conv_time_tab_subsample[] = { 84, 148, 276, 532 };
 298 static const int ina219_conv_time_tab_average[] = { 532, 1060, 2130, 4260,
 299                                                     8510, 17020, 34050, 68100};
 300
 301 static int ina219_lookup_int_time(unsigned int *val_us, int *bits)
 302 {
 303         if (*val_us > 68100 || *val_us < 84)
 304                 return -EINVAL;
 305
 306         if (*val_us <= 532) {
 307                 *bits = find_closest(*val_us, ina219_conv_time_tab_subsample,
 308                                     ARRAY_SIZE(ina219_conv_time_tab_subsample));
 309                 *val_us = ina219_conv_time_tab_subsample[*bits];
 310         } else {
 311                 *bits = find_closest(*val_us, ina219_conv_time_tab_average,
 312                                     ARRAY_SIZE(ina219_conv_time_tab_average));
 313                 *val_us = ina219_conv_time_tab_average[*bits];
 314                 *bits |= 0x8;
 315         }
 316
 317         return 0;
 318 }
 319
 320 static int ina219_set_int_time_vbus(struct ina2xx_chip_info *chip,
 321                                     unsigned int val_us, unsigned int *config)
 322 {
 323         int bits, ret;
 324         unsigned int val_us_best = val_us;
 325
 326         ret = ina219_lookup_int_time(&val_us_best, &bits);
 327         if (ret)
 328                 return ret;
 329
 330         chip->int_time_vbus = val_us_best;
 331
 332         *config &= ~INA219_ITB_MASK;
 333         *config |= INA219_SHIFT_ITB(bits) & INA219_ITB_MASK;
 334
 335         return 0;
 336 }
 337
 338 static int ina219_set_int_time_vshunt(struct ina2xx_chip_info *chip,
 339                                       unsigned int val_us, unsigned int *config)
 340 {
 341         int bits, ret;
 342         unsigned int val_us_best = val_us;
 343
 344         ret = ina219_lookup_int_time(&val_us_best, &bits);
 345         if (ret)
 346                 return ret;
 347
 348         chip->int_time_vshunt = val_us_best;
 349
 350         *config &= ~INA219_ITS_MASK;
 351         *config |= INA219_SHIFT_ITS(bits) & INA219_ITS_MASK;
 352
 353         return 0;
 354 }
 355
 356 static int ina2xx_write_raw(struct iio_dev *indio_dev,
 357                             struct iio_chan_spec const *chan,
 358                             int val, int val2, long mask)
 359 {
 360         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 361         unsigned int config, tmp;
 362         int ret;
 363
 364         if (iio_buffer_enabled(indio_dev))
 365                 return -EBUSY;
 366
 367         mutex_lock(&chip->state_lock);
 368
 369         ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
 370         if (ret)
 371                 goto err;
 372
 373         tmp = config;
 374
 375         switch (mask) {
 376         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 377                 ret = ina226_set_average(chip, val, &tmp);
 378                 break;
 379
 380         case IIO_CHAN_INFO_INT_TIME:
 381                 if (chip->config->chip_id == ina226) {
 382                         if (chan->address == INA2XX_SHUNT_VOLTAGE)
 383                                 ret = ina226_set_int_time_vshunt(chip, val2,
 384                                                                  &tmp);
 385                         else
 386                                 ret = ina226_set_int_time_vbus(chip, val2,
 387                                                                &tmp);
 388                 } else {
 389                         if (chan->address == INA2XX_SHUNT_VOLTAGE)
 390                                 ret = ina219_set_int_time_vshunt(chip, val2,
 391                                                                  &tmp);
 392                         else
 393                                 ret = ina219_set_int_time_vbus(chip, val2,
 394                                                                &tmp);
 395                 }
 396                 break;
 397
 398         default:
 399                 ret = -EINVAL;
 400         }
 401
 402         if (!ret && (tmp != config))
 403                 ret = regmap_write(chip->regmap, INA2XX_CONFIG, tmp);
 404 err:
 405         mutex_unlock(&chip->state_lock);
 406
 407         return ret;
 408 }
 409
 410 static ssize_t ina2xx_allow_async_readout_show(struct device *dev,
 411                                            struct device_attribute *attr,
 412                                            char *buf)
 413 {
 414         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 415
 416         return sprintf(buf, "%d\n", chip->allow_async_readout);
 417 }
 418
 419 static ssize_t ina2xx_allow_async_readout_store(struct device *dev,
 420                                 struct device_attribute *attr,
 421                                 const char *buf, size_t len)
 422 {
 423         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 424         bool val;
 425         int ret;
 426
 427         ret = strtobool((const char *) buf, &val);
 428         if (ret)
 429                 return ret;
 430
 431         chip->allow_async_readout = val;
 432
 433         return len;
 434 }
 435
 436 /*
 437  * Set current LSB to 1mA, shunt is in uOhms
 438  * (equation 13 in datasheet). We hardcode a Current_LSB
 439  * of 1.0 x10-6. The only remaining parameter is RShunt.
 440  * There is no need to expose the CALIBRATION register
 441  * to the user for now. But we need to reset this register
 442  * if the user updates RShunt after driver init, e.g upon
 443  * reading an EEPROM/Probe-type value.
 444  */
 445 static int ina2xx_set_calibration(struct ina2xx_chip_info *chip)
 446 {
 447         u16 regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor,
 448                                    chip->shunt_resistor);
 449
 450         return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval);
 451 }
 452
 453 static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val)
 454 {
 455         if (val <= 0 || val > chip->config->calibration_factor)
 456                 return -EINVAL;
 457
 458         chip->shunt_resistor = val;
 459
 460         return 0;
 461 }
 462
 463 static ssize_t ina2xx_shunt_resistor_show(struct device *dev,
 464                                           struct device_attribute *attr,
 465                                           char *buf)
 466 {
 467         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 468
 469         return sprintf(buf, "%d\n", chip->shunt_resistor);
 470 }
 471
 472 static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
 473                                            struct device_attribute *attr,
 474                                            const char *buf, size_t len)
 475 {
 476         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 477         unsigned long val;
 478         int ret;
 479
 480         ret = kstrtoul((const char *) buf, 10, &val);
 481         if (ret)
 482                 return ret;
 483
 484         ret = set_shunt_resistor(chip, val);
 485         if (ret)
 486                 return ret;
 487
 488         /* Update the Calibration register */
 489         ret = ina2xx_set_calibration(chip);
 490         if (ret)
 491                 return ret;
 492
 493         return len;
 494 }
 495
 496 #define INA219_CHAN(_type, _index, _address) { \
 497         .type = (_type), \
 498         .address = (_address), \
 499         .indexed = 1, \
 500         .channel = (_index), \
 501         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 502                               BIT(IIO_CHAN_INFO_SCALE), \
 503         .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
 504         .scan_index = (_index), \
 505         .scan_type = { \
 506                 .sign = 'u', \
 507                 .realbits = 16, \
 508                 .storagebits = 16, \
 509                 .endianness = IIO_CPU, \
 510         } \
 511 }
 512
 513 #define INA226_CHAN(_type, _index, _address) { \
 514         .type = (_type), \
 515         .address = (_address), \
 516         .indexed = 1, \
 517         .channel = (_index), \
 518         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 519                               BIT(IIO_CHAN_INFO_SCALE), \
 520         .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
 521                                    BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
 522         .scan_index = (_index), \
 523         .scan_type = { \
 524                 .sign = 'u', \
 525                 .realbits = 16, \
 526                 .storagebits = 16, \
 527                 .endianness = IIO_CPU, \
 528         } \
 529 }
 530
 531 /*
 532  * Sampling Freq is a consequence of the integration times of
 533  * the Voltage channels.
 534  */
 535 #define INA219_CHAN_VOLTAGE(_index, _address) { \
 536         .type = IIO_VOLTAGE, \
 537         .address = (_address), \
 538         .indexed = 1, \
 539         .channel = (_index), \
 540         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 541                               BIT(IIO_CHAN_INFO_SCALE) | \
 542                               BIT(IIO_CHAN_INFO_INT_TIME), \
 543         .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
 544         .scan_index = (_index), \
 545         .scan_type = { \
 546                 .sign = 'u', \
 547                 .realbits = 16, \
 548                 .storagebits = 16, \
 549                 .endianness = IIO_LE, \
 550         } \
 551 }
 552
 553 #define INA226_CHAN_VOLTAGE(_index, _address) { \
 554         .type = IIO_VOLTAGE, \
 555         .address = (_address), \
 556         .indexed = 1, \
 557         .channel = (_index), \
 558         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 559                               BIT(IIO_CHAN_INFO_SCALE) | \
 560                               BIT(IIO_CHAN_INFO_INT_TIME), \
 561         .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
 562                                    BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
 563         .scan_index = (_index), \
 564         .scan_type = { \
 565                 .sign = 'u', \
 566                 .realbits = 16, \
 567                 .storagebits = 16, \
 568                 .endianness = IIO_LE, \
 569         } \
 570 }
 571
 572
 573 static const struct iio_chan_spec ina226_channels[] = {
 574         INA226_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
 575         INA226_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
 576         INA226_CHAN(IIO_POWER, 2, INA2XX_POWER),
 577         INA226_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
 578         IIO_CHAN_SOFT_TIMESTAMP(4),
 579 };
 580
 581 static const struct iio_chan_spec ina219_channels[] = {
 582         INA219_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
 583         INA219_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
 584         INA219_CHAN(IIO_POWER, 2, INA2XX_POWER),
 585         INA219_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
 586         IIO_CHAN_SOFT_TIMESTAMP(4),
 587 };
 588
 589 static int ina2xx_work_buffer(struct iio_dev *indio_dev)
 590 {
 591         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 592         unsigned short data[8];
 593         int bit, ret, i = 0;
 594         s64 time_a, time_b;
 595         unsigned int alert;
 596         int cnvr_need_clear = 0;
 597
 598         time_a = iio_get_time_ns(indio_dev);
 599
 600         /*
 601          * Because the timer thread and the chip conversion clock
 602          * are asynchronous, the period difference will eventually
 603          * result in reading V[k-1] again, or skip V[k] at time Tk.
 604          * In order to resync the timer with the conversion process
 605          * we check the ConVersionReadyFlag.
 606          * On hardware that supports using the ALERT pin to toggle a
 607          * GPIO a triggered buffer could be used instead.
 608          * For now, we do an extra read of the MASK_ENABLE register (INA226)
 609          * resp. the BUS_VOLTAGE register (INA219).
 610          */
 611         if (!chip->allow_async_readout)
 612                 do {
 613                         if (chip->config->chip_id == ina226) {
 614                                 ret = regmap_read(chip->regmap,
 615                                                   INA226_MASK_ENABLE, &alert);
 616                                 alert &= INA226_CVRF;
 617                         } else {
 618                                 ret = regmap_read(chip->regmap,
 619                                                   INA2XX_BUS_VOLTAGE, &alert);
 620                                 alert &= INA219_CNVR;
 621                                 cnvr_need_clear = alert;
 622                         }
 623
 624                         if (ret < 0)
 625                                 return ret;
 626
 627                 } while (!alert);
 628
 629         /*
 630          * Single register reads: bulk_read will not work with ina226/219
 631          * as there is no auto-increment of the register pointer.
 632          */
 633         for_each_set_bit(bit, indio_dev->active_scan_mask,
 634                          indio_dev->masklength) {
 635                 unsigned int val;
 636
 637                 ret = regmap_read(chip->regmap,
 638                                   INA2XX_SHUNT_VOLTAGE + bit, &val);
 639                 if (ret < 0)
 640                         return ret;
 641
 642                 data[i++] = val;
 643
 644                 if (INA2XX_SHUNT_VOLTAGE + bit == INA2XX_POWER)
 645                         cnvr_need_clear = 0;
 646         }
 647
 648         /* Dummy read on INA219 power register to clear CNVR flag */
 649         if (cnvr_need_clear && chip->config->chip_id == ina219) {
 650                 unsigned int val;
 651
 652                 ret = regmap_read(chip->regmap, INA2XX_POWER, &val);
 653                 if (ret < 0)
 654                         return ret;
 655         }
 656
 657         time_b = iio_get_time_ns(indio_dev);
 658
 659         iio_push_to_buffers_with_timestamp(indio_dev,
 660                                            (unsigned int *)data, time_a);
 661
 662         return (unsigned long)(time_b - time_a) / 1000;
 663 };
 664
 665 static int ina2xx_capture_thread(void *data)
 666 {
 667         struct iio_dev *indio_dev = data;
 668         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 669         int sampling_us = SAMPLING_PERIOD(chip);
 670         int buffer_us;
 671
 672         /*
 673          * Poll a bit faster than the chip internal Fs, in case
 674          * we wish to sync with the conversion ready flag.
 675          */
 676         if (!chip->allow_async_readout)
 677                 sampling_us -= 200;
 678
 679         do {
 680                 buffer_us = ina2xx_work_buffer(indio_dev);
 681                 if (buffer_us < 0)
 682                         return buffer_us;
 683
 684                 if (sampling_us > buffer_us)
 685                         udelay(sampling_us - buffer_us);
 686
 687         } while (!kthread_should_stop());
 688
 689         return 0;
 690 }
 691
 692 static int ina2xx_buffer_enable(struct iio_dev *indio_dev)
 693 {
 694         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 695         unsigned int sampling_us = SAMPLING_PERIOD(chip);
 696
 697         dev_dbg(&indio_dev->dev, "Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n",
 698                 (unsigned int)(*indio_dev->active_scan_mask),
 699                 1000000 / sampling_us, chip->avg);
 700
 701         dev_dbg(&indio_dev->dev, "Expected work period: %u us\n", sampling_us);
 702         dev_dbg(&indio_dev->dev, "Async readout mode: %d\n",
 703                 chip->allow_async_readout);
 704
 705         chip->task = kthread_run(ina2xx_capture_thread, (void *)indio_dev,
 706                                  "%s:%d-%uus", indio_dev->name, indio_dev->id,
 707                                  sampling_us);
 708
 709         return PTR_ERR_OR_ZERO(chip->task);
 710 }
 711
 712 static int ina2xx_buffer_disable(struct iio_dev *indio_dev)
 713 {
 714         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 715
 716         if (chip->task) {
 717                 kthread_stop(chip->task);
 718                 chip->task = NULL;
 719         }
 720
 721         return 0;
 722 }
 723
 724 static const struct iio_buffer_setup_ops ina2xx_setup_ops = {
 725         .postenable = &ina2xx_buffer_enable,
 726         .predisable = &ina2xx_buffer_disable,
 727 };
 728
 729 static int ina2xx_debug_reg(struct iio_dev *indio_dev,
 730                             unsigned reg, unsigned writeval, unsigned *readval)
 731 {
 732         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 733
 734         if (!readval)
 735                 return regmap_write(chip->regmap, reg, writeval);
 736
 737         return regmap_read(chip->regmap, reg, readval);
 738 }
 739
 740 /* Possible integration times for vshunt and vbus */
 741 static IIO_CONST_ATTR_NAMED(ina219_integration_time_available,
 742                             integration_time_available,
 743                             "0.000084 0.000148 0.000276 0.000532 0.001060 0.002130 0.004260 0.008510 0.017020 0.034050 0.068100");
 744
 745 static IIO_CONST_ATTR_NAMED(ina226_integration_time_available,
 746                             integration_time_available,
 747                             "0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");
 748
 749
 750 static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR,
 751                        ina2xx_allow_async_readout_show,
 752                        ina2xx_allow_async_readout_store, 0);
 753
 754 static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR,
 755                        ina2xx_shunt_resistor_show,
 756                        ina2xx_shunt_resistor_store, 0);
 757
 758 static struct attribute *ina219_attributes[] = {
 759         &iio_dev_attr_in_allow_async_readout.dev_attr.attr,
 760         &iio_const_attr_ina219_integration_time_available.dev_attr.attr,
 761         &iio_dev_attr_in_shunt_resistor.dev_attr.attr,
 762         NULL,
 763 };
 764
 765 static struct attribute *ina226_attributes[] = {
 766         &iio_dev_attr_in_allow_async_readout.dev_attr.attr,
 767         &iio_const_attr_ina226_integration_time_available.dev_attr.attr,
 768         &iio_dev_attr_in_shunt_resistor.dev_attr.attr,
 769         NULL,
 770 };
 771
 772 static const struct attribute_group ina219_attribute_group = {
 773         .attrs = ina219_attributes,
 774 };
 775
 776 static const struct attribute_group ina226_attribute_group = {
 777         .attrs = ina226_attributes,
 778 };
 779
 780 static const struct iio_info ina219_info = {
 781         .driver_module = THIS_MODULE,
 782         .attrs = &ina219_attribute_group,
 783         .read_raw = ina2xx_read_raw,
 784         .write_raw = ina2xx_write_raw,
 785         .debugfs_reg_access = ina2xx_debug_reg,
 786 };
 787
 788 static const struct iio_info ina226_info = {
 789         .driver_module = THIS_MODULE,
 790         .attrs = &ina226_attribute_group,
 791         .read_raw = ina2xx_read_raw,
 792         .write_raw = ina2xx_write_raw,
 793         .debugfs_reg_access = ina2xx_debug_reg,
 794 };
 795
 796 /* Initialize the configuration and calibration registers. */
 797 static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
 798 {
 799         int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config);
 800         if (ret)
 801                 return ret;
 802
 803         return ina2xx_set_calibration(chip);
 804 }
 805
 806 static int ina2xx_probe(struct i2c_client *client,
 807                         const struct i2c_device_id *id)
 808 {
 809         struct ina2xx_chip_info *chip;
 810         struct iio_dev *indio_dev;
 811         struct iio_buffer *buffer;
 812         unsigned int val;
 813         enum ina2xx_ids type;
 814         int ret;
 815
 816         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
 817         if (!indio_dev)
 818                 return -ENOMEM;
 819
 820         chip = iio_priv(indio_dev);
 821
 822         /* This is only used for device removal purposes. */
 823         i2c_set_clientdata(client, indio_dev);
 824
 825         chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
 826         if (IS_ERR(chip->regmap)) {
 827                 dev_err(&client->dev, "failed to allocate register map\n");
 828                 return PTR_ERR(chip->regmap);
 829         }
 830
 831         if (client->dev.of_node)
 832                 type = (enum ina2xx_ids)of_device_get_match_data(&client->dev);
 833         else
 834                 type = id->driver_data;
 835         chip->config = &ina2xx_config[type];
 836
 837         mutex_init(&chip->state_lock);
 838
 839         if (of_property_read_u32(client->dev.of_node,
 840                                  "shunt-resistor", &val) < 0) {
 841                 struct ina2xx_platform_data *pdata =
 842                     dev_get_platdata(&client->dev);
 843
 844                 if (pdata)
 845                         val = pdata->shunt_uohms;
 846                 else
 847                         val = INA2XX_RSHUNT_DEFAULT;
 848         }
 849
 850         ret = set_shunt_resistor(chip, val);
 851         if (ret)
 852                 return ret;
 853
 854         /* Patch the current config register with default. */
 855         val = chip->config->config_default;
 856
 857         if (id->driver_data == ina226) {
 858                 ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
 859                 ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
 860                 ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
 861         } else {
 862                 chip->avg = 1;
 863                 ina219_set_int_time_vbus(chip, INA219_DEFAULT_IT, &val);
 864                 ina219_set_int_time_vshunt(chip, INA219_DEFAULT_IT, &val);
 865         }
 866
 867         ret = ina2xx_init(chip, val);
 868         if (ret) {
 869                 dev_err(&client->dev, "error configuring the device\n");
 870                 return ret;
 871         }
 872
 873         indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
 874         indio_dev->dev.parent = &client->dev;
 875         indio_dev->dev.of_node = client->dev.of_node;
 876         if (id->driver_data == ina226) {
 877                 indio_dev->channels = ina226_channels;
 878                 indio_dev->num_channels = ARRAY_SIZE(ina226_channels);
 879                 indio_dev->info = &ina226_info;
 880         } else {
 881                 indio_dev->channels = ina219_channels;
 882                 indio_dev->num_channels = ARRAY_SIZE(ina219_channels);
 883                 indio_dev->info = &ina219_info;
 884         }
 885         indio_dev->name = id->name;
 886         indio_dev->setup_ops = &ina2xx_setup_ops;
 887
 888         buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
 889         if (!buffer)
 890                 return -ENOMEM;
 891
 892         iio_device_attach_buffer(indio_dev, buffer);
 893
 894         return iio_device_register(indio_dev);
 895 }
 896
 897 static int ina2xx_remove(struct i2c_client *client)
 898 {
 899         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 900         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 901
 902         iio_device_unregister(indio_dev);
 903
 904         /* Powerdown */
 905         return regmap_update_bits(chip->regmap, INA2XX_CONFIG,
 906                                   INA2XX_MODE_MASK, 0);
 907 }
 908
 909 static const struct i2c_device_id ina2xx_id[] = {
 910         {"ina219", ina219},
 911         {"ina220", ina219},
 912         {"ina226", ina226},
 913         {"ina230", ina226},
 914         {"ina231", ina226},
 915         {}
 916 };
 917 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
 918
 919 static const struct of_device_id ina2xx_of_match[] = {
 920         {
 921                 .compatible = "ti,ina219",
 922                 .data = (void *)ina219
 923         },
 924         {
 925                 .compatible = "ti,ina220",
 926                 .data = (void *)ina219
 927         },
 928         {
 929                 .compatible = "ti,ina226",
 930                 .data = (void *)ina226
 931         },
 932         {
 933                 .compatible = "ti,ina230",
 934                 .data = (void *)ina226
 935         },
 936         {
 937                 .compatible = "ti,ina231",
 938                 .data = (void *)ina226
 939         },
 940         {},
 941 };
 942 MODULE_DEVICE_TABLE(of, ina2xx_of_match);
 943
 944 static struct i2c_driver ina2xx_driver = {
 945         .driver = {
 946                    .name = KBUILD_MODNAME,
 947                    .of_match_table = ina2xx_of_match,
 948         },
 949         .probe = ina2xx_probe,
 950         .remove = ina2xx_remove,
 951         .id_table = ina2xx_id,
 952 };
 953 module_i2c_driver(ina2xx_driver);
 954
 955 MODULE_AUTHOR("Marc Titinger <marc.titinger@baylibre.com>");
 956 MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver");
 957 MODULE_LICENSE("GPL v2");