drivers/iio/adc/ina2xx-adc.c

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

DEFINITIONS
