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/sched/task.h>
  34 #include <linux/util_macros.h>
  35
  36 #include <linux/platform_data/ina2xx.h>
  37
  38 /* INA2XX registers definition */
  39 #define INA2XX_CONFIG                   0x00
  40 #define INA2XX_SHUNT_VOLTAGE            0x01    /* readonly */
  41 #define INA2XX_BUS_VOLTAGE              0x02    /* readonly */
  42 #define INA2XX_POWER                    0x03    /* readonly */
  43 #define INA2XX_CURRENT                  0x04    /* readonly */
  44 #define INA2XX_CALIBRATION              0x05
  45
  46 #define INA226_MASK_ENABLE              0x06
  47 #define INA226_CVRF                     BIT(3)
  48
  49 #define INA2XX_MAX_REGISTERS            8
  50
  51 /* settings - depend on use case */
  52 #define INA219_CONFIG_DEFAULT           0x399F  /* PGA=1/8, BRNG=32V */
  53 #define INA219_DEFAULT_IT               532
  54 #define INA219_DEFAULT_BRNG             1   /* 32V */
  55 #define INA219_DEFAULT_PGA              125 /* 1000/8 */
  56 #define INA226_CONFIG_DEFAULT           0x4327
  57 #define INA226_DEFAULT_AVG              4
  58 #define INA226_DEFAULT_IT               1110
  59
  60 #define INA2XX_RSHUNT_DEFAULT           10000
  61
  62 /*
  63  * bit masks for reading the settings in the configuration register
  64  * FIXME: use regmap_fields.
  65  */
  66 #define INA2XX_MODE_MASK        GENMASK(3, 0)
  67
  68 /* Gain for VShunt: 1/8 (default), 1/4, 1/2, 1 */
  69 #define INA219_PGA_MASK         GENMASK(12, 11)
  70 #define INA219_SHIFT_PGA(val)   ((val) << 11)
  71
  72 /* VBus range: 32V (default), 16V */
  73 #define INA219_BRNG_MASK        BIT(13)
  74 #define INA219_SHIFT_BRNG(val)  ((val) << 13)
  75
  76 /* Averaging for VBus/VShunt/Power */
  77 #define INA226_AVG_MASK         GENMASK(11, 9)
  78 #define INA226_SHIFT_AVG(val)   ((val) << 9)
  79
  80 /* Integration time for VBus */
  81 #define INA219_ITB_MASK         GENMASK(10, 7)
  82 #define INA219_SHIFT_ITB(val)   ((val) << 7)
  83 #define INA226_ITB_MASK         GENMASK(8, 6)
  84 #define INA226_SHIFT_ITB(val)   ((val) << 6)
  85
  86 /* Integration time for VShunt */
  87 #define INA219_ITS_MASK         GENMASK(6, 3)
  88 #define INA219_SHIFT_ITS(val)   ((val) << 3)
  89 #define INA226_ITS_MASK         GENMASK(5, 3)
  90 #define INA226_SHIFT_ITS(val)   ((val) << 3)
  91
  92 /* INA219 Bus voltage register, low bits are flags */
  93 #define INA219_OVF              BIT(0)
  94 #define INA219_CNVR             BIT(1)
  95 #define INA219_BUS_VOLTAGE_SHIFT        3
  96
  97 /* Cosmetic macro giving the sampling period for a full P=UxI cycle */
  98 #define SAMPLING_PERIOD(c)      ((c->int_time_vbus + c->int_time_vshunt) \
  99                                  * c->avg)
 100
 101 static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg)
 102 {
 103         return (reg == INA2XX_CONFIG) || (reg > INA2XX_CURRENT);
 104 }
 105
 106 static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg)
 107 {
 108         return (reg != INA2XX_CONFIG);
 109 }
 110
 111 static inline bool is_signed_reg(unsigned int reg)
 112 {
 113         return (reg == INA2XX_SHUNT_VOLTAGE) || (reg == INA2XX_CURRENT);
 114 }
 115
 116 static const struct regmap_config ina2xx_regmap_config = {
 117         .reg_bits = 8,
 118         .val_bits = 16,
 119         .max_register = INA2XX_MAX_REGISTERS,
 120         .writeable_reg = ina2xx_is_writeable_reg,
 121         .volatile_reg = ina2xx_is_volatile_reg,
 122 };
 123
 124 enum ina2xx_ids { ina219, ina226 };
 125
 126 struct ina2xx_config {
 127         u16 config_default;
 128         int calibration_value;
 129         int shunt_voltage_lsb;  /* nV */
 130         int bus_voltage_shift;  /* position of lsb */
 131         int bus_voltage_lsb;    /* uV */
 132         /* fixed relation between current and power lsb, uW/uA */
 133         int power_lsb_factor;
 134         enum ina2xx_ids chip_id;
 135 };
 136
 137 struct ina2xx_chip_info {
 138         struct regmap *regmap;
 139         struct task_struct *task;
 140         const struct ina2xx_config *config;
 141         struct mutex state_lock;
 142         unsigned int shunt_resistor_uohm;
 143         int avg;
 144         int int_time_vbus; /* Bus voltage integration time uS */
 145         int int_time_vshunt; /* Shunt voltage integration time uS */
 146         int range_vbus; /* Bus voltage maximum in V */
 147         int pga_gain_vshunt; /* Shunt voltage PGA gain */
 148         bool allow_async_readout;
 149         /* data buffer needs space for channel data and timestamp */
 150         struct {
 151                 u16 chan[4];
 152                 u64 ts __aligned(8);
 153         } scan;
 154 };
 155
 156 static const struct ina2xx_config ina2xx_config[] = {
 157         [ina219] = {
 158                 .config_default = INA219_CONFIG_DEFAULT,
 159                 .calibration_value = 4096,
 160                 .shunt_voltage_lsb = 10000,
 161                 .bus_voltage_shift = INA219_BUS_VOLTAGE_SHIFT,
 162                 .bus_voltage_lsb = 4000,
 163                 .power_lsb_factor = 20,
 164                 .chip_id = ina219,
 165         },
 166         [ina226] = {
 167                 .config_default = INA226_CONFIG_DEFAULT,
 168                 .calibration_value = 2048,
 169                 .shunt_voltage_lsb = 2500,
 170                 .bus_voltage_shift = 0,
 171                 .bus_voltage_lsb = 1250,
 172                 .power_lsb_factor = 25,
 173                 .chip_id = ina226,
 174         },
 175 };
 176
 177 static int ina2xx_read_raw(struct iio_dev *indio_dev,
 178                            struct iio_chan_spec const *chan,
 179                            int *val, int *val2, long mask)
 180 {
 181         int ret;
 182         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 183         unsigned int regval;
 184
 185         switch (mask) {
 186         case IIO_CHAN_INFO_RAW:
 187                 ret = regmap_read(chip->regmap, chan->address, &regval);
 188                 if (ret)
 189                         return ret;
 190
 191                 if (is_signed_reg(chan->address))
 192                         *val = (s16) regval;
 193                 else
 194                         *val  = regval;
 195
 196                 if (chan->address == INA2XX_BUS_VOLTAGE)
 197                         *val >>= chip->config->bus_voltage_shift;
 198
 199                 return IIO_VAL_INT;
 200
 201         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 202                 *val = chip->avg;
 203                 return IIO_VAL_INT;
 204
 205         case IIO_CHAN_INFO_INT_TIME:
 206                 *val = 0;
 207                 if (chan->address == INA2XX_SHUNT_VOLTAGE)
 208                         *val2 = chip->int_time_vshunt;
 209                 else
 210                         *val2 = chip->int_time_vbus;
 211
 212                 return IIO_VAL_INT_PLUS_MICRO;
 213
 214         case IIO_CHAN_INFO_SAMP_FREQ:
 215                 /*
 216                  * Sample freq is read only, it is a consequence of
 217                  * 1/AVG*(CT_bus+CT_shunt).
 218                  */
 219                 *val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip));
 220
 221                 return IIO_VAL_INT;
 222
 223         case IIO_CHAN_INFO_SCALE:
 224                 switch (chan->address) {
 225                 case INA2XX_SHUNT_VOLTAGE:
 226                         /* processed (mV) = raw * lsb(nV) / 1000000 */
 227                         *val = chip->config->shunt_voltage_lsb;
 228                         *val2 = 1000000;
 229                         return IIO_VAL_FRACTIONAL;
 230
 231                 case INA2XX_BUS_VOLTAGE:
 232                         /* processed (mV) = raw * lsb (uV) / 1000 */
 233                         *val = chip->config->bus_voltage_lsb;
 234                         *val2 = 1000;
 235                         return IIO_VAL_FRACTIONAL;
 236
 237                 case INA2XX_CURRENT:
 238                         /*
 239                          * processed (mA) = raw * current_lsb (mA)
 240                          * current_lsb (mA) = shunt_voltage_lsb (nV) /
 241                          *                    shunt_resistor (uOhm)
 242                          */
 243                         *val = chip->config->shunt_voltage_lsb;
 244                         *val2 = chip->shunt_resistor_uohm;
 245                         return IIO_VAL_FRACTIONAL;
 246
 247                 case INA2XX_POWER:
 248                         /*
 249                          * processed (mW) = raw * power_lsb (mW)
 250                          * power_lsb (mW) = power_lsb_factor (mW/mA) *
 251                          *                  current_lsb (mA)
 252                          */
 253                         *val = chip->config->power_lsb_factor *
 254                                chip->config->shunt_voltage_lsb;
 255                         *val2 = chip->shunt_resistor_uohm;
 256                         return IIO_VAL_FRACTIONAL;
 257                 }
 258                 return -EINVAL;
 259
 260         case IIO_CHAN_INFO_HARDWAREGAIN:
 261                 switch (chan->address) {
 262                 case INA2XX_SHUNT_VOLTAGE:
 263                         *val = chip->pga_gain_vshunt;
 264                         *val2 = 1000;
 265                         return IIO_VAL_FRACTIONAL;
 266
 267                 case INA2XX_BUS_VOLTAGE:
 268                         *val = chip->range_vbus == 32 ? 1 : 2;
 269                         return IIO_VAL_INT;
 270                 }
 271                 return -EINVAL;
 272         }
 273
 274         return -EINVAL;
 275 }
 276
 277 /*
 278  * Available averaging rates for ina226. The indices correspond with
 279  * the bit values expected by the chip (according to the ina226 datasheet,
 280  * table 3 AVG bit settings, found at
 281  * https://www.ti.com/lit/ds/symlink/ina226.pdf.
 282  */
 283 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
 284
 285 static int ina226_set_average(struct ina2xx_chip_info *chip, unsigned int val,
 286                               unsigned int *config)
 287 {
 288         int bits;
 289
 290         if (val > 1024 || val < 1)
 291                 return -EINVAL;
 292
 293         bits = find_closest(val, ina226_avg_tab,
 294                             ARRAY_SIZE(ina226_avg_tab));
 295
 296         chip->avg = ina226_avg_tab[bits];
 297
 298         *config &= ~INA226_AVG_MASK;
 299         *config |= INA226_SHIFT_AVG(bits) & INA226_AVG_MASK;
 300
 301         return 0;
 302 }
 303
 304 /* Conversion times in uS */
 305 static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100,
 306                                             2116, 4156, 8244 };
 307
 308 static int ina226_set_int_time_vbus(struct ina2xx_chip_info *chip,
 309                                     unsigned int val_us, unsigned int *config)
 310 {
 311         int bits;
 312
 313         if (val_us > 8244 || val_us < 140)
 314                 return -EINVAL;
 315
 316         bits = find_closest(val_us, ina226_conv_time_tab,
 317                             ARRAY_SIZE(ina226_conv_time_tab));
 318
 319         chip->int_time_vbus = ina226_conv_time_tab[bits];
 320
 321         *config &= ~INA226_ITB_MASK;
 322         *config |= INA226_SHIFT_ITB(bits) & INA226_ITB_MASK;
 323
 324         return 0;
 325 }
 326
 327 static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip,
 328                                       unsigned int val_us, unsigned int *config)
 329 {
 330         int bits;
 331
 332         if (val_us > 8244 || val_us < 140)
 333                 return -EINVAL;
 334
 335         bits = find_closest(val_us, ina226_conv_time_tab,
 336                             ARRAY_SIZE(ina226_conv_time_tab));
 337
 338         chip->int_time_vshunt = ina226_conv_time_tab[bits];
 339
 340         *config &= ~INA226_ITS_MASK;
 341         *config |= INA226_SHIFT_ITS(bits) & INA226_ITS_MASK;
 342
 343         return 0;
 344 }
 345
 346 /* Conversion times in uS. */
 347 static const int ina219_conv_time_tab_subsample[] = { 84, 148, 276, 532 };
 348 static const int ina219_conv_time_tab_average[] = { 532, 1060, 2130, 4260,
 349                                                     8510, 17020, 34050, 68100};
 350
 351 static int ina219_lookup_int_time(unsigned int *val_us, int *bits)
 352 {
 353         if (*val_us > 68100 || *val_us < 84)
 354                 return -EINVAL;
 355
 356         if (*val_us <= 532) {
 357                 *bits = find_closest(*val_us, ina219_conv_time_tab_subsample,
 358                                     ARRAY_SIZE(ina219_conv_time_tab_subsample));
 359                 *val_us = ina219_conv_time_tab_subsample[*bits];
 360         } else {
 361                 *bits = find_closest(*val_us, ina219_conv_time_tab_average,
 362                                     ARRAY_SIZE(ina219_conv_time_tab_average));
 363                 *val_us = ina219_conv_time_tab_average[*bits];
 364                 *bits |= 0x8;
 365         }
 366
 367         return 0;
 368 }
 369
 370 static int ina219_set_int_time_vbus(struct ina2xx_chip_info *chip,
 371                                     unsigned int val_us, unsigned int *config)
 372 {
 373         int bits, ret;
 374         unsigned int val_us_best = val_us;
 375
 376         ret = ina219_lookup_int_time(&val_us_best, &bits);
 377         if (ret)
 378                 return ret;
 379
 380         chip->int_time_vbus = val_us_best;
 381
 382         *config &= ~INA219_ITB_MASK;
 383         *config |= INA219_SHIFT_ITB(bits) & INA219_ITB_MASK;
 384
 385         return 0;
 386 }
 387
 388 static int ina219_set_int_time_vshunt(struct ina2xx_chip_info *chip,
 389                                       unsigned int val_us, unsigned int *config)
 390 {
 391         int bits, ret;
 392         unsigned int val_us_best = val_us;
 393
 394         ret = ina219_lookup_int_time(&val_us_best, &bits);
 395         if (ret)
 396                 return ret;
 397
 398         chip->int_time_vshunt = val_us_best;
 399
 400         *config &= ~INA219_ITS_MASK;
 401         *config |= INA219_SHIFT_ITS(bits) & INA219_ITS_MASK;
 402
 403         return 0;
 404 }
 405
 406 static const int ina219_vbus_range_tab[] = { 1, 2 };
 407 static int ina219_set_vbus_range_denom(struct ina2xx_chip_info *chip,
 408                                        unsigned int range,
 409                                        unsigned int *config)
 410 {
 411         if (range == 1)
 412                 chip->range_vbus = 32;
 413         else if (range == 2)
 414                 chip->range_vbus = 16;
 415         else
 416                 return -EINVAL;
 417
 418         *config &= ~INA219_BRNG_MASK;
 419         *config |= INA219_SHIFT_BRNG(range == 1 ? 1 : 0) & INA219_BRNG_MASK;
 420
 421         return 0;
 422 }
 423
 424 static const int ina219_vshunt_gain_tab[] = { 125, 250, 500, 1000 };
 425 static const int ina219_vshunt_gain_frac[] = {
 426         125, 1000, 250, 1000, 500, 1000, 1000, 1000 };
 427
 428 static int ina219_set_vshunt_pga_gain(struct ina2xx_chip_info *chip,
 429                                       unsigned int gain,
 430                                       unsigned int *config)
 431 {
 432         int bits;
 433
 434         if (gain < 125 || gain > 1000)
 435                 return -EINVAL;
 436
 437         bits = find_closest(gain, ina219_vshunt_gain_tab,
 438                             ARRAY_SIZE(ina219_vshunt_gain_tab));
 439
 440         chip->pga_gain_vshunt = ina219_vshunt_gain_tab[bits];
 441         bits = 3 - bits;
 442
 443         *config &= ~INA219_PGA_MASK;
 444         *config |= INA219_SHIFT_PGA(bits) & INA219_PGA_MASK;
 445
 446         return 0;
 447 }
 448
 449 static int ina2xx_read_avail(struct iio_dev *indio_dev,
 450                              struct iio_chan_spec const *chan,
 451                              const int **vals, int *type, int *length,
 452                              long mask)
 453 {
 454         switch (mask) {
 455         case IIO_CHAN_INFO_HARDWAREGAIN:
 456                 switch (chan->address) {
 457                 case INA2XX_SHUNT_VOLTAGE:
 458                         *type = IIO_VAL_FRACTIONAL;
 459                         *length = sizeof(ina219_vshunt_gain_frac) / sizeof(int);
 460                         *vals = ina219_vshunt_gain_frac;
 461                         return IIO_AVAIL_LIST;
 462
 463                 case INA2XX_BUS_VOLTAGE:
 464                         *type = IIO_VAL_INT;
 465                         *length = sizeof(ina219_vbus_range_tab) / sizeof(int);
 466                         *vals = ina219_vbus_range_tab;
 467                         return IIO_AVAIL_LIST;
 468                 }
 469         }
 470
 471         return -EINVAL;
 472 }
 473
 474 static int ina2xx_write_raw(struct iio_dev *indio_dev,
 475                             struct iio_chan_spec const *chan,
 476                             int val, int val2, long mask)
 477 {
 478         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 479         unsigned int config, tmp;
 480         int ret;
 481
 482         if (iio_buffer_enabled(indio_dev))
 483                 return -EBUSY;
 484
 485         mutex_lock(&chip->state_lock);
 486
 487         ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
 488         if (ret)
 489                 goto err;
 490
 491         tmp = config;
 492
 493         switch (mask) {
 494         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 495                 ret = ina226_set_average(chip, val, &tmp);
 496                 break;
 497
 498         case IIO_CHAN_INFO_INT_TIME:
 499                 if (chip->config->chip_id == ina226) {
 500                         if (chan->address == INA2XX_SHUNT_VOLTAGE)
 501                                 ret = ina226_set_int_time_vshunt(chip, val2,
 502                                                                  &tmp);
 503                         else
 504                                 ret = ina226_set_int_time_vbus(chip, val2,
 505                                                                &tmp);
 506                 } else {
 507                         if (chan->address == INA2XX_SHUNT_VOLTAGE)
 508                                 ret = ina219_set_int_time_vshunt(chip, val2,
 509                                                                  &tmp);
 510                         else
 511                                 ret = ina219_set_int_time_vbus(chip, val2,
 512                                                                &tmp);
 513                 }
 514                 break;
 515
 516         case IIO_CHAN_INFO_HARDWAREGAIN:
 517                 if (chan->address == INA2XX_SHUNT_VOLTAGE)
 518                         ret = ina219_set_vshunt_pga_gain(chip, val * 1000 +
 519                                                          val2 / 1000, &tmp);
 520                 else
 521                         ret = ina219_set_vbus_range_denom(chip, val, &tmp);
 522                 break;
 523
 524         default:
 525                 ret = -EINVAL;
 526         }
 527
 528         if (!ret && (tmp != config))
 529                 ret = regmap_write(chip->regmap, INA2XX_CONFIG, tmp);
 530 err:
 531         mutex_unlock(&chip->state_lock);
 532
 533         return ret;
 534 }
 535
 536 static ssize_t ina2xx_allow_async_readout_show(struct device *dev,
 537                                            struct device_attribute *attr,
 538                                            char *buf)
 539 {
 540         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 541
 542         return sprintf(buf, "%d\n", chip->allow_async_readout);
 543 }
 544
 545 static ssize_t ina2xx_allow_async_readout_store(struct device *dev,
 546                                 struct device_attribute *attr,
 547                                 const char *buf, size_t len)
 548 {
 549         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 550         bool val;
 551         int ret;
 552
 553         ret = strtobool((const char *) buf, &val);
 554         if (ret)
 555                 return ret;
 556
 557         chip->allow_async_readout = val;
 558
 559         return len;
 560 }
 561
 562 /*
 563  * Calibration register is set to the best value, which eliminates
 564  * truncation errors on calculating current register in hardware.
 565  * According to datasheet (INA 226: eq. 3, INA219: eq. 4) the best values
 566  * are 2048 for ina226 and 4096 for ina219. They are hardcoded as
 567  * calibration_value.
 568  */
 569 static int ina2xx_set_calibration(struct ina2xx_chip_info *chip)
 570 {
 571         return regmap_write(chip->regmap, INA2XX_CALIBRATION,
 572                             chip->config->calibration_value);
 573 }
 574
 575 static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val)
 576 {
 577         if (val == 0 || val > INT_MAX)
 578                 return -EINVAL;
 579
 580         chip->shunt_resistor_uohm = val;
 581
 582         return 0;
 583 }
 584
 585 static ssize_t ina2xx_shunt_resistor_show(struct device *dev,
 586                                           struct device_attribute *attr,
 587                                           char *buf)
 588 {
 589         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 590         int vals[2] = { chip->shunt_resistor_uohm, 1000000 };
 591
 592         return iio_format_value(buf, IIO_VAL_FRACTIONAL, 1, vals);
 593 }
 594
 595 static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
 596                                            struct device_attribute *attr,
 597                                            const char *buf, size_t len)
 598 {
 599         struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 600         int val, val_fract, ret;
 601
 602         ret = iio_str_to_fixpoint(buf, 100000, &val, &val_fract);
 603         if (ret)
 604                 return ret;
 605
 606         ret = set_shunt_resistor(chip, val * 1000000 + val_fract);
 607         if (ret)
 608                 return ret;
 609
 610         return len;
 611 }
 612
 613 #define INA219_CHAN(_type, _index, _address) { \
 614         .type = (_type), \
 615         .address = (_address), \
 616         .indexed = 1, \
 617         .channel = (_index), \
 618         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 619                               BIT(IIO_CHAN_INFO_SCALE), \
 620         .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
 621         .scan_index = (_index), \
 622         .scan_type = { \
 623                 .sign = 'u', \
 624                 .realbits = 16, \
 625                 .storagebits = 16, \
 626                 .endianness = IIO_CPU, \
 627         } \
 628 }
 629
 630 #define INA226_CHAN(_type, _index, _address) { \
 631         .type = (_type), \
 632         .address = (_address), \
 633         .indexed = 1, \
 634         .channel = (_index), \
 635         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 636                               BIT(IIO_CHAN_INFO_SCALE), \
 637         .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
 638                                    BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
 639         .scan_index = (_index), \
 640         .scan_type = { \
 641                 .sign = 'u', \
 642                 .realbits = 16, \
 643                 .storagebits = 16, \
 644                 .endianness = IIO_CPU, \
 645         } \
 646 }
 647
 648 /*
 649  * Sampling Freq is a consequence of the integration times of
 650  * the Voltage channels.
 651  */
 652 #define INA219_CHAN_VOLTAGE(_index, _address, _shift) { \
 653         .type = IIO_VOLTAGE, \
 654         .address = (_address), \
 655         .indexed = 1, \
 656         .channel = (_index), \
 657         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 658                               BIT(IIO_CHAN_INFO_SCALE) | \
 659                               BIT(IIO_CHAN_INFO_INT_TIME) | \
 660                               BIT(IIO_CHAN_INFO_HARDWAREGAIN), \
 661         .info_mask_separate_available = \
 662                               BIT(IIO_CHAN_INFO_HARDWAREGAIN), \
 663         .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
 664         .scan_index = (_index), \
 665         .scan_type = { \
 666                 .sign = 'u', \
 667                 .shift = _shift, \
 668                 .realbits = 16 - _shift, \
 669                 .storagebits = 16, \
 670                 .endianness = IIO_LE, \
 671         } \
 672 }
 673
 674 #define INA226_CHAN_VOLTAGE(_index, _address) { \
 675         .type = IIO_VOLTAGE, \
 676         .address = (_address), \
 677         .indexed = 1, \
 678         .channel = (_index), \
 679         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 680                               BIT(IIO_CHAN_INFO_SCALE) | \
 681                               BIT(IIO_CHAN_INFO_INT_TIME), \
 682         .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
 683                                    BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
 684         .scan_index = (_index), \
 685         .scan_type = { \
 686                 .sign = 'u', \
 687                 .realbits = 16, \
 688                 .storagebits = 16, \
 689                 .endianness = IIO_LE, \
 690         } \
 691 }
 692
 693
 694 static const struct iio_chan_spec ina226_channels[] = {
 695         INA226_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
 696         INA226_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
 697         INA226_CHAN(IIO_POWER, 2, INA2XX_POWER),
 698         INA226_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
 699         IIO_CHAN_SOFT_TIMESTAMP(4),
 700 };
 701
 702 static const struct iio_chan_spec ina219_channels[] = {
 703         INA219_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE, 0),
 704         INA219_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE, INA219_BUS_VOLTAGE_SHIFT),
 705         INA219_CHAN(IIO_POWER, 2, INA2XX_POWER),
 706         INA219_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
 707         IIO_CHAN_SOFT_TIMESTAMP(4),
 708 };
 709
 710 static int ina2xx_conversion_ready(struct iio_dev *indio_dev)
 711 {
 712         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 713         int ret;
 714         unsigned int alert;
 715
 716         /*
 717          * Because the timer thread and the chip conversion clock
 718          * are asynchronous, the period difference will eventually
 719          * result in reading V[k-1] again, or skip V[k] at time Tk.
 720          * In order to resync the timer with the conversion process
 721          * we check the ConVersionReadyFlag.
 722          * On hardware that supports using the ALERT pin to toggle a
 723          * GPIO a triggered buffer could be used instead.
 724          * For now, we do an extra read of the MASK_ENABLE register (INA226)
 725          * resp. the BUS_VOLTAGE register (INA219).
 726          */
 727         if (chip->config->chip_id == ina226) {
 728                 ret = regmap_read(chip->regmap,
 729                                   INA226_MASK_ENABLE, &alert);
 730                 alert &= INA226_CVRF;
 731         } else {
 732                 ret = regmap_read(chip->regmap,
 733                                   INA2XX_BUS_VOLTAGE, &alert);
 734                 alert &= INA219_CNVR;
 735         }
 736
 737         if (ret < 0)
 738                 return ret;
 739
 740         return !!alert;
 741 }
 742
 743 static int ina2xx_work_buffer(struct iio_dev *indio_dev)
 744 {
 745         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 746         int bit, ret, i = 0;
 747         s64 time;
 748
 749         time = iio_get_time_ns(indio_dev);
 750
 751         /*
 752          * Single register reads: bulk_read will not work with ina226/219
 753          * as there is no auto-increment of the register pointer.
 754          */
 755         for_each_set_bit(bit, indio_dev->active_scan_mask,
 756                          indio_dev->masklength) {
 757                 unsigned int val;
 758
 759                 ret = regmap_read(chip->regmap,
 760                                   INA2XX_SHUNT_VOLTAGE + bit, &val);
 761                 if (ret < 0)
 762                         return ret;
 763
 764                 chip->scan.chan[i++] = val;
 765         }
 766
 767         iio_push_to_buffers_with_timestamp(indio_dev, &chip->scan, time);
 768
 769         return 0;
 770 };
 771
 772 static int ina2xx_capture_thread(void *data)
 773 {
 774         struct iio_dev *indio_dev = data;
 775         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 776         int sampling_us = SAMPLING_PERIOD(chip);
 777         int ret;
 778         struct timespec64 next, now, delta;
 779         s64 delay_us;
 780
 781         /*
 782          * Poll a bit faster than the chip internal Fs, in case
 783          * we wish to sync with the conversion ready flag.
 784          */
 785         if (!chip->allow_async_readout)
 786                 sampling_us -= 200;
 787
 788         ktime_get_ts64(&next);
 789
 790         do {
 791                 while (!chip->allow_async_readout) {
 792                         ret = ina2xx_conversion_ready(indio_dev);
 793                         if (ret < 0)
 794                                 return ret;
 795
 796                         /*
 797                          * If the conversion was not yet finished,
 798                          * reset the reference timestamp.
 799                          */
 800                         if (ret == 0)
 801                                 ktime_get_ts64(&next);
 802                         else
 803                                 break;
 804                 }
 805
 806                 ret = ina2xx_work_buffer(indio_dev);
 807                 if (ret < 0)
 808                         return ret;
 809
 810                 ktime_get_ts64(&now);
 811
 812                 /*
 813                  * Advance the timestamp for the next poll by one sampling
 814                  * interval, and sleep for the remainder (next - now)
 815                  * In case "next" has already passed, the interval is added
 816                  * multiple times, i.e. samples are dropped.
 817                  */
 818                 do {
 819                         timespec64_add_ns(&next, 1000 * sampling_us);
 820                         delta = timespec64_sub(next, now);
 821                         delay_us = div_s64(timespec64_to_ns(&delta), 1000);
 822                 } while (delay_us <= 0);
 823
 824                 usleep_range(delay_us, (delay_us * 3) >> 1);
 825
 826         } while (!kthread_should_stop());
 827
 828         return 0;
 829 }
 830
 831 static int ina2xx_buffer_enable(struct iio_dev *indio_dev)
 832 {
 833         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 834         unsigned int sampling_us = SAMPLING_PERIOD(chip);
 835         struct task_struct *task;
 836
 837         dev_dbg(&indio_dev->dev, "Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n",
 838                 (unsigned int)(*indio_dev->active_scan_mask),
 839                 1000000 / sampling_us, chip->avg);
 840
 841         dev_dbg(&indio_dev->dev, "Expected work period: %u us\n", sampling_us);
 842         dev_dbg(&indio_dev->dev, "Async readout mode: %d\n",
 843                 chip->allow_async_readout);
 844
 845         task = kthread_create(ina2xx_capture_thread, (void *)indio_dev,
 846                               "%s:%d-%uus", indio_dev->name, indio_dev->id,
 847                               sampling_us);
 848         if (IS_ERR(task))
 849                 return PTR_ERR(task);
 850
 851         get_task_struct(task);
 852         wake_up_process(task);
 853         chip->task = task;
 854
 855         return 0;
 856 }
 857
 858 static int ina2xx_buffer_disable(struct iio_dev *indio_dev)
 859 {
 860         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 861
 862         if (chip->task) {
 863                 kthread_stop(chip->task);
 864                 put_task_struct(chip->task);
 865                 chip->task = NULL;
 866         }
 867
 868         return 0;
 869 }
 870
 871 static const struct iio_buffer_setup_ops ina2xx_setup_ops = {
 872         .postenable = &ina2xx_buffer_enable,
 873         .predisable = &ina2xx_buffer_disable,
 874 };
 875
 876 static int ina2xx_debug_reg(struct iio_dev *indio_dev,
 877                             unsigned reg, unsigned writeval, unsigned *readval)
 878 {
 879         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 880
 881         if (!readval)
 882                 return regmap_write(chip->regmap, reg, writeval);
 883
 884         return regmap_read(chip->regmap, reg, readval);
 885 }
 886
 887 /* Possible integration times for vshunt and vbus */
 888 static IIO_CONST_ATTR_NAMED(ina219_integration_time_available,
 889                             integration_time_available,
 890                             "0.000084 0.000148 0.000276 0.000532 0.001060 0.002130 0.004260 0.008510 0.017020 0.034050 0.068100");
 891
 892 static IIO_CONST_ATTR_NAMED(ina226_integration_time_available,
 893                             integration_time_available,
 894                             "0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");
 895
 896 static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR,
 897                        ina2xx_allow_async_readout_show,
 898                        ina2xx_allow_async_readout_store, 0);
 899
 900 static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR,
 901                        ina2xx_shunt_resistor_show,
 902                        ina2xx_shunt_resistor_store, 0);
 903
 904 static struct attribute *ina219_attributes[] = {
 905         &iio_dev_attr_in_allow_async_readout.dev_attr.attr,
 906         &iio_const_attr_ina219_integration_time_available.dev_attr.attr,
 907         &iio_dev_attr_in_shunt_resistor.dev_attr.attr,
 908         NULL,
 909 };
 910
 911 static struct attribute *ina226_attributes[] = {
 912         &iio_dev_attr_in_allow_async_readout.dev_attr.attr,
 913         &iio_const_attr_ina226_integration_time_available.dev_attr.attr,
 914         &iio_dev_attr_in_shunt_resistor.dev_attr.attr,
 915         NULL,
 916 };
 917
 918 static const struct attribute_group ina219_attribute_group = {
 919         .attrs = ina219_attributes,
 920 };
 921
 922 static const struct attribute_group ina226_attribute_group = {
 923         .attrs = ina226_attributes,
 924 };
 925
 926 static const struct iio_info ina219_info = {
 927         .attrs = &ina219_attribute_group,
 928         .read_raw = ina2xx_read_raw,
 929         .read_avail = ina2xx_read_avail,
 930         .write_raw = ina2xx_write_raw,
 931         .debugfs_reg_access = ina2xx_debug_reg,
 932 };
 933
 934 static const struct iio_info ina226_info = {
 935         .attrs = &ina226_attribute_group,
 936         .read_raw = ina2xx_read_raw,
 937         .write_raw = ina2xx_write_raw,
 938         .debugfs_reg_access = ina2xx_debug_reg,
 939 };
 940
 941 /* Initialize the configuration and calibration registers. */
 942 static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
 943 {
 944         int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config);
 945         if (ret)
 946                 return ret;
 947
 948         return ina2xx_set_calibration(chip);
 949 }
 950
 951 static int ina2xx_probe(struct i2c_client *client,
 952                         const struct i2c_device_id *id)
 953 {
 954         struct ina2xx_chip_info *chip;
 955         struct iio_dev *indio_dev;
 956         struct iio_buffer *buffer;
 957         unsigned int val;
 958         enum ina2xx_ids type;
 959         int ret;
 960
 961         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
 962         if (!indio_dev)
 963                 return -ENOMEM;
 964
 965         chip = iio_priv(indio_dev);
 966
 967         /* This is only used for device removal purposes. */
 968         i2c_set_clientdata(client, indio_dev);
 969
 970         chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
 971         if (IS_ERR(chip->regmap)) {
 972                 dev_err(&client->dev, "failed to allocate register map\n");
 973                 return PTR_ERR(chip->regmap);
 974         }
 975
 976         if (client->dev.of_node)
 977                 type = (enum ina2xx_ids)of_device_get_match_data(&client->dev);
 978         else
 979                 type = id->driver_data;
 980         chip->config = &ina2xx_config[type];
 981
 982         mutex_init(&chip->state_lock);
 983
 984         if (of_property_read_u32(client->dev.of_node,
 985                                  "shunt-resistor", &val) < 0) {
 986                 struct ina2xx_platform_data *pdata =
 987                     dev_get_platdata(&client->dev);
 988
 989                 if (pdata)
 990                         val = pdata->shunt_uohms;
 991                 else
 992                         val = INA2XX_RSHUNT_DEFAULT;
 993         }
 994
 995         ret = set_shunt_resistor(chip, val);
 996         if (ret)
 997                 return ret;
 998
 999         /* Patch the current config register with default. */
1000         val = chip->config->config_default;
1001
1002         if (id->driver_data == ina226) {
1003                 ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
1004                 ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
1005                 ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
1006         } else {
1007                 chip->avg = 1;
1008                 ina219_set_int_time_vbus(chip, INA219_DEFAULT_IT, &val);
1009                 ina219_set_int_time_vshunt(chip, INA219_DEFAULT_IT, &val);
1010                 ina219_set_vbus_range_denom(chip, INA219_DEFAULT_BRNG, &val);
1011                 ina219_set_vshunt_pga_gain(chip, INA219_DEFAULT_PGA, &val);
1012         }
1013
1014         ret = ina2xx_init(chip, val);
1015         if (ret) {
1016                 dev_err(&client->dev, "error configuring the device\n");
1017                 return ret;
1018         }
1019
1020         indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
1021         if (id->driver_data == ina226) {
1022                 indio_dev->channels = ina226_channels;
1023                 indio_dev->num_channels = ARRAY_SIZE(ina226_channels);
1024                 indio_dev->info = &ina226_info;
1025         } else {
1026                 indio_dev->channels = ina219_channels;
1027                 indio_dev->num_channels = ARRAY_SIZE(ina219_channels);
1028                 indio_dev->info = &ina219_info;
1029         }
1030         indio_dev->name = id->name;
1031         indio_dev->setup_ops = &ina2xx_setup_ops;
1032
1033         buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
1034         if (!buffer)
1035                 return -ENOMEM;
1036
1037         iio_device_attach_buffer(indio_dev, buffer);
1038
1039         return iio_device_register(indio_dev);
1040 }
1041
1042 static int ina2xx_remove(struct i2c_client *client)
1043 {
1044         struct iio_dev *indio_dev = i2c_get_clientdata(client);
1045         struct ina2xx_chip_info *chip = iio_priv(indio_dev);
1046
1047         iio_device_unregister(indio_dev);
1048
1049         /* Powerdown */
1050         return regmap_update_bits(chip->regmap, INA2XX_CONFIG,
1051                                   INA2XX_MODE_MASK, 0);
1052 }
1053
1054 static const struct i2c_device_id ina2xx_id[] = {
1055         {"ina219", ina219},
1056         {"ina220", ina219},
1057         {"ina226", ina226},
1058         {"ina230", ina226},
1059         {"ina231", ina226},
1060         {}
1061 };
1062 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
1063
1064 static const struct of_device_id ina2xx_of_match[] = {
1065         {
1066                 .compatible = "ti,ina219",
1067                 .data = (void *)ina219
1068         },
1069         {
1070                 .compatible = "ti,ina220",
1071                 .data = (void *)ina219
1072         },
1073         {
1074                 .compatible = "ti,ina226",
1075                 .data = (void *)ina226
1076         },
1077         {
1078                 .compatible = "ti,ina230",
1079                 .data = (void *)ina226
1080         },
1081         {
1082                 .compatible = "ti,ina231",
1083                 .data = (void *)ina226
1084         },
1085         {},
1086 };
1087 MODULE_DEVICE_TABLE(of, ina2xx_of_match);
1088
1089 static struct i2c_driver ina2xx_driver = {
1090         .driver = {
1091                    .name = KBUILD_MODNAME,
1092                    .of_match_table = ina2xx_of_match,
1093         },
1094         .probe = ina2xx_probe,
1095         .remove = ina2xx_remove,
1096         .id_table = ina2xx_id,
1097 };
1098 module_i2c_driver(ina2xx_driver);
1099
1100 MODULE_AUTHOR("Marc Titinger <marc.titinger@baylibre.com>");
1101 MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver");
1102 MODULE_LICENSE("GPL v2");