drivers/iio/adc/rtq6056.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2022 Richtek Technology Corp.
   4  *
   5  * ChiYuan Huang <cy_huang@richtek.com>
   6  */
   7
   8 #include <linux/bitops.h>
   9 #include <linux/delay.h>
  10 #include <linux/i2c.h>
  11 #include <linux/kernel.h>
  12 #include <linux/mod_devicetable.h>
  13 #include <linux/module.h>
  14 #include <linux/pm_runtime.h>
  15 #include <linux/property.h>
  16 #include <linux/regmap.h>
  17 #include <linux/sysfs.h>
  18 #include <linux/types.h>
  19 #include <linux/util_macros.h>
  20
  21 #include <linux/iio/buffer.h>
  22 #include <linux/iio/iio.h>
  23 #include <linux/iio/sysfs.h>
  24 #include <linux/iio/trigger_consumer.h>
  25 #include <linux/iio/triggered_buffer.h>
  26
  27 #define RTQ6056_REG_CONFIG      0x00
  28 #define RTQ6056_REG_SHUNTVOLT   0x01
  29 #define RTQ6056_REG_BUSVOLT     0x02
  30 #define RTQ6056_REG_POWER       0x03
  31 #define RTQ6056_REG_CURRENT     0x04
  32 #define RTQ6056_REG_CALIBRATION 0x05
  33 #define RTQ6056_REG_MASKENABLE  0x06
  34 #define RTQ6056_REG_ALERTLIMIT  0x07
  35 #define RTQ6056_REG_MANUFACTID  0xFE
  36 #define RTQ6056_REG_DIEID       0xFF
  37
  38 #define RTQ6056_VENDOR_ID       0x1214
  39 #define RTQ6056_DEFAULT_CONFIG  0x4127
  40 #define RTQ6056_CONT_ALLON      7
  41
  42 enum {
  43         RTQ6056_CH_VSHUNT = 0,
  44         RTQ6056_CH_VBUS,
  45         RTQ6056_CH_POWER,
  46         RTQ6056_CH_CURRENT,
  47         RTQ6056_MAX_CHANNEL
  48 };
  49
  50 enum {
  51         F_OPMODE = 0,
  52         F_VSHUNTCT,
  53         F_VBUSCT,
  54         F_AVG,
  55         F_RESET,
  56         F_MAX_FIELDS
  57 };
  58
  59 struct rtq6056_priv {
  60         struct device *dev;
  61         struct regmap *regmap;
  62         struct regmap_field *rm_fields[F_MAX_FIELDS];
  63         u32 shunt_resistor_uohm;
  64         int vshuntct_us;
  65         int vbusct_us;
  66         int avg_sample;
  67 };
  68
  69 static const struct reg_field rtq6056_reg_fields[F_MAX_FIELDS] = {
  70         [F_OPMODE] = REG_FIELD(RTQ6056_REG_CONFIG, 0, 2),
  71         [F_VSHUNTCT] = REG_FIELD(RTQ6056_REG_CONFIG, 3, 5),
  72         [F_VBUSCT] = REG_FIELD(RTQ6056_REG_CONFIG, 6, 8),
  73         [F_AVG] = REG_FIELD(RTQ6056_REG_CONFIG, 9, 11),
  74         [F_RESET] = REG_FIELD(RTQ6056_REG_CONFIG, 15, 15),
  75 };
  76
  77 static const struct iio_chan_spec rtq6056_channels[RTQ6056_MAX_CHANNEL + 1] = {
  78         {
  79                 .type = IIO_VOLTAGE,
  80                 .indexed = 1,
  81                 .channel = 0,
  82                 .address = RTQ6056_REG_SHUNTVOLT,
  83                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
  84                                       BIT(IIO_CHAN_INFO_SCALE) |
  85                                       BIT(IIO_CHAN_INFO_SAMP_FREQ),
  86                 .info_mask_separate_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
  87                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
  88                 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
  89                 .scan_index = 0,
  90                 .scan_type = {
  91                         .sign = 's',
  92                         .realbits = 16,
  93                         .storagebits = 16,
  94                         .endianness = IIO_CPU,
  95                 },
  96         },
  97         {
  98                 .type = IIO_VOLTAGE,
  99                 .indexed = 1,
 100                 .channel = 1,
 101                 .address = RTQ6056_REG_BUSVOLT,
 102                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 103                                       BIT(IIO_CHAN_INFO_SCALE) |
 104                                       BIT(IIO_CHAN_INFO_SAMP_FREQ),
 105                 .info_mask_separate_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 106                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 107                 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 108                 .scan_index = 1,
 109                 .scan_type = {
 110                         .sign = 'u',
 111                         .realbits = 16,
 112                         .storagebits = 16,
 113                         .endianness = IIO_CPU,
 114                 },
 115         },
 116         {
 117                 .type = IIO_POWER,
 118                 .indexed = 1,
 119                 .channel = 2,
 120                 .address = RTQ6056_REG_POWER,
 121                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 122                                       BIT(IIO_CHAN_INFO_SCALE) |
 123                                       BIT(IIO_CHAN_INFO_SAMP_FREQ),
 124                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 125                 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 126                 .scan_index = 2,
 127                 .scan_type = {
 128                         .sign = 'u',
 129                         .realbits = 16,
 130                         .storagebits = 16,
 131                         .endianness = IIO_CPU,
 132                 },
 133         },
 134         {
 135                 .type = IIO_CURRENT,
 136                 .indexed = 1,
 137                 .channel = 3,
 138                 .address = RTQ6056_REG_CURRENT,
 139                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 140                                       BIT(IIO_CHAN_INFO_SAMP_FREQ),
 141                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 142                 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 143                 .scan_index = 3,
 144                 .scan_type = {
 145                         .sign = 's',
 146                         .realbits = 16,
 147                         .storagebits = 16,
 148                         .endianness = IIO_CPU,
 149                 },
 150         },
 151         IIO_CHAN_SOFT_TIMESTAMP(RTQ6056_MAX_CHANNEL),
 152 };
 153
 154 static int rtq6056_adc_read_channel(struct rtq6056_priv *priv,
 155                                     struct iio_chan_spec const *ch,
 156                                     int *val)
 157 {
 158         struct device *dev = priv->dev;
 159         unsigned int addr = ch->address;
 160         unsigned int regval;
 161         int ret;
 162
 163         pm_runtime_get_sync(dev);
 164         ret = regmap_read(priv->regmap, addr, &regval);
 165         pm_runtime_mark_last_busy(dev);
 166         pm_runtime_put(dev);
 167         if (ret)
 168                 return ret;
 169
 170         /* Power and VBUS is unsigned 16-bit, others are signed 16-bit */
 171         if (addr == RTQ6056_REG_BUSVOLT || addr == RTQ6056_REG_POWER)
 172                 *val = regval;
 173         else
 174                 *val = sign_extend32(regval, 16);
 175
 176         return IIO_VAL_INT;
 177 }
 178
 179 static int rtq6056_adc_read_scale(struct iio_chan_spec const *ch, int *val,
 180                                   int *val2)
 181 {
 182         switch (ch->address) {
 183         case RTQ6056_REG_SHUNTVOLT:
 184                 /* VSHUNT lsb  2.5uV */
 185                 *val = 2500;
 186                 *val2 = 1000000;
 187                 return IIO_VAL_FRACTIONAL;
 188         case RTQ6056_REG_BUSVOLT:
 189                 /* VBUS lsb 1.25mV */
 190                 *val = 1250;
 191                 *val2 = 1000;
 192                 return IIO_VAL_FRACTIONAL;
 193         case RTQ6056_REG_POWER:
 194                 /* Power lsb 25mW */
 195                 *val = 25;
 196                 return IIO_VAL_INT;
 197         default:
 198                 return -EINVAL;
 199         }
 200 }
 201
 202 /*
 203  * Sample frequency for channel VSHUNT and VBUS. The indices correspond
 204  * with the bit value expected by the chip. And it can be found at
 205  * https://www.richtek.com/assets/product_file/RTQ6056/DSQ6056-00.pdf
 206  */
 207 static const int rtq6056_samp_freq_list[] = {
 208         7194, 4926, 3717, 1904, 964, 485, 243, 122,
 209 };
 210
 211 static int rtq6056_adc_set_samp_freq(struct rtq6056_priv *priv,
 212                                      struct iio_chan_spec const *ch, int val)
 213 {
 214         struct regmap_field *rm_field;
 215         unsigned int selector;
 216         int *ct, ret;
 217
 218         if (val > 7194 || val < 122)
 219                 return -EINVAL;
 220
 221         if (ch->address == RTQ6056_REG_SHUNTVOLT) {
 222                 rm_field = priv->rm_fields[F_VSHUNTCT];
 223                 ct = &priv->vshuntct_us;
 224         } else if (ch->address == RTQ6056_REG_BUSVOLT) {
 225                 rm_field = priv->rm_fields[F_VBUSCT];
 226                 ct = &priv->vbusct_us;
 227         } else
 228                 return -EINVAL;
 229
 230         selector = find_closest_descending(val, rtq6056_samp_freq_list,
 231                                            ARRAY_SIZE(rtq6056_samp_freq_list));
 232
 233         ret = regmap_field_write(rm_field, selector);
 234         if (ret)
 235                 return ret;
 236
 237         *ct = 1000000 / rtq6056_samp_freq_list[selector];
 238
 239         return 0;
 240 }
 241
 242 /*
 243  * Available averaging rate for rtq6056. The indices correspond with the bit
 244  * value expected by the chip. And it can be found at
 245  * https://www.richtek.com/assets/product_file/RTQ6056/DSQ6056-00.pdf
 246  */
 247 static const int rtq6056_avg_sample_list[] = {
 248         1, 4, 16, 64, 128, 256, 512, 1024,
 249 };
 250
 251 static int rtq6056_adc_set_average(struct rtq6056_priv *priv, int val)
 252 {
 253         unsigned int selector;
 254         int ret;
 255
 256         if (val > 1024 || val < 1)
 257                 return -EINVAL;
 258
 259         selector = find_closest(val, rtq6056_avg_sample_list,
 260                                 ARRAY_SIZE(rtq6056_avg_sample_list));
 261
 262         ret = regmap_field_write(priv->rm_fields[F_AVG], selector);
 263         if (ret)
 264                 return ret;
 265
 266         priv->avg_sample = rtq6056_avg_sample_list[selector];
 267
 268         return 0;
 269 }
 270
 271 static int rtq6056_adc_get_sample_freq(struct rtq6056_priv *priv,
 272                                        struct iio_chan_spec const *ch, int *val)
 273 {
 274         int sample_time;
 275
 276         if (ch->address == RTQ6056_REG_SHUNTVOLT)
 277                 sample_time = priv->vshuntct_us;
 278         else if (ch->address == RTQ6056_REG_BUSVOLT)
 279                 sample_time = priv->vbusct_us;
 280         else {
 281                 sample_time = priv->vshuntct_us + priv->vbusct_us;
 282                 sample_time *= priv->avg_sample;
 283         }
 284
 285         *val = 1000000 / sample_time;
 286
 287         return IIO_VAL_INT;
 288 }
 289
 290 static int rtq6056_adc_read_raw(struct iio_dev *indio_dev,
 291                                 struct iio_chan_spec const *chan, int *val,
 292                                 int *val2, long mask)
 293 {
 294         struct rtq6056_priv *priv = iio_priv(indio_dev);
 295
 296         switch (mask) {
 297         case IIO_CHAN_INFO_RAW:
 298                 return rtq6056_adc_read_channel(priv, chan, val);
 299         case IIO_CHAN_INFO_SCALE:
 300                 return rtq6056_adc_read_scale(chan, val, val2);
 301         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 302                 *val = priv->avg_sample;
 303                 return IIO_VAL_INT;
 304         case IIO_CHAN_INFO_SAMP_FREQ:
 305                 return rtq6056_adc_get_sample_freq(priv, chan, val);
 306         default:
 307                 return -EINVAL;
 308         }
 309 }
 310
 311 static int rtq6056_adc_read_avail(struct iio_dev *indio_dev,
 312                                   struct iio_chan_spec const *chan,
 313                                   const int **vals, int *type, int *length,
 314                                   long mask)
 315 {
 316         switch (mask) {
 317         case IIO_CHAN_INFO_SAMP_FREQ:
 318                 *vals = rtq6056_samp_freq_list;
 319                 *type = IIO_VAL_INT;
 320                 *length = ARRAY_SIZE(rtq6056_samp_freq_list);
 321                 return IIO_AVAIL_LIST;
 322         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 323                 *vals = rtq6056_avg_sample_list;
 324                 *type = IIO_VAL_INT;
 325                 *length = ARRAY_SIZE(rtq6056_avg_sample_list);
 326                 return IIO_AVAIL_LIST;
 327         default:
 328                 return -EINVAL;
 329         }
 330 }
 331
 332 static int rtq6056_adc_write_raw(struct iio_dev *indio_dev,
 333                                  struct iio_chan_spec const *chan, int val,
 334                                  int val2, long mask)
 335 {
 336         struct rtq6056_priv *priv = iio_priv(indio_dev);
 337         int ret;
 338
 339         ret = iio_device_claim_direct_mode(indio_dev);
 340         if (ret)
 341                 return ret;
 342
 343         switch (mask) {
 344         case IIO_CHAN_INFO_SAMP_FREQ:
 345                 ret = rtq6056_adc_set_samp_freq(priv, chan, val);
 346                 break;
 347         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 348                 ret = rtq6056_adc_set_average(priv, val);
 349                 break;
 350         default:
 351                 ret = -EINVAL;
 352                 break;
 353         }
 354
 355         iio_device_release_direct_mode(indio_dev);
 356
 357         return ret;
 358 }
 359
 360 static const char *rtq6056_channel_labels[RTQ6056_MAX_CHANNEL] = {
 361         [RTQ6056_CH_VSHUNT] = "Vshunt",
 362         [RTQ6056_CH_VBUS] = "Vbus",
 363         [RTQ6056_CH_POWER] = "Power",
 364         [RTQ6056_CH_CURRENT] = "Current",
 365 };
 366
 367 static int rtq6056_adc_read_label(struct iio_dev *indio_dev,
 368                                   struct iio_chan_spec const *chan,
 369                                   char *label)
 370 {
 371         return sysfs_emit(label, "%s\n", rtq6056_channel_labels[chan->channel]);
 372 }
 373
 374 static int rtq6056_set_shunt_resistor(struct rtq6056_priv *priv,
 375                                       int resistor_uohm)
 376 {
 377         unsigned int calib_val;
 378         int ret;
 379
 380         if (resistor_uohm <= 0) {
 381                 dev_err(priv->dev, "Invalid resistor [%d]\n", resistor_uohm);
 382                 return -EINVAL;
 383         }
 384
 385         /* calibration = 5120000 / (Rshunt (uOhm) * current lsb (1mA)) */
 386         calib_val = 5120000 / resistor_uohm;
 387         ret = regmap_write(priv->regmap, RTQ6056_REG_CALIBRATION, calib_val);
 388         if (ret)
 389                 return ret;
 390
 391         priv->shunt_resistor_uohm = resistor_uohm;
 392
 393         return 0;
 394 }
 395
 396 static ssize_t shunt_resistor_show(struct device *dev,
 397                                    struct device_attribute *attr, char *buf)
 398 {
 399         struct rtq6056_priv *priv = iio_priv(dev_to_iio_dev(dev));
 400         int vals[2] = { priv->shunt_resistor_uohm, 1000000 };
 401
 402         return iio_format_value(buf, IIO_VAL_FRACTIONAL, 1, vals);
 403 }
 404
 405 static ssize_t shunt_resistor_store(struct device *dev,
 406                                     struct device_attribute *attr,
 407                                     const char *buf, size_t len)
 408 {
 409         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 410         struct rtq6056_priv *priv = iio_priv(indio_dev);
 411         int val, val_fract, ret;
 412
 413         ret = iio_device_claim_direct_mode(indio_dev);
 414         if (ret)
 415                 return ret;
 416
 417         ret = iio_str_to_fixpoint(buf, 100000, &val, &val_fract);
 418         if (ret)
 419                 goto out_store;
 420
 421         ret = rtq6056_set_shunt_resistor(priv, val * 1000000 + val_fract);
 422
 423 out_store:
 424         iio_device_release_direct_mode(indio_dev);
 425
 426         return ret ?: len;
 427 }
 428
 429 static IIO_DEVICE_ATTR_RW(shunt_resistor, 0);
 430
 431 static struct attribute *rtq6056_attributes[] = {
 432         &iio_dev_attr_shunt_resistor.dev_attr.attr,
 433         NULL
 434 };
 435
 436 static const struct attribute_group rtq6056_attribute_group = {
 437         .attrs = rtq6056_attributes,
 438 };
 439
 440 static const struct iio_info rtq6056_info = {
 441         .attrs = &rtq6056_attribute_group,
 442         .read_raw = rtq6056_adc_read_raw,
 443         .read_avail = rtq6056_adc_read_avail,
 444         .write_raw = rtq6056_adc_write_raw,
 445         .read_label = rtq6056_adc_read_label,
 446 };
 447
 448 static irqreturn_t rtq6056_buffer_trigger_handler(int irq, void *p)
 449 {
 450         struct iio_poll_func *pf = p;
 451         struct iio_dev *indio_dev = pf->indio_dev;
 452         struct rtq6056_priv *priv = iio_priv(indio_dev);
 453         struct device *dev = priv->dev;
 454         struct {
 455                 u16 vals[RTQ6056_MAX_CHANNEL];
 456                 s64 timestamp __aligned(8);
 457         } data;
 458         unsigned int raw;
 459         int i = 0, bit, ret;
 460
 461         memset(&data, 0, sizeof(data));
 462
 463         pm_runtime_get_sync(dev);
 464
 465         for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->masklength) {
 466                 unsigned int addr = rtq6056_channels[bit].address;
 467
 468                 ret = regmap_read(priv->regmap, addr, &raw);
 469                 if (ret)
 470                         goto out;
 471
 472                 data.vals[i++] = raw;
 473         }
 474
 475         iio_push_to_buffers_with_timestamp(indio_dev, &data, iio_get_time_ns(indio_dev));
 476
 477 out:
 478         pm_runtime_mark_last_busy(dev);
 479         pm_runtime_put(dev);
 480
 481         iio_trigger_notify_done(indio_dev->trig);
 482
 483         return IRQ_HANDLED;
 484 }
 485
 486 static void rtq6056_enter_shutdown_state(void *dev)
 487 {
 488         struct rtq6056_priv *priv = dev_get_drvdata(dev);
 489
 490         /* Enter shutdown state */
 491         regmap_field_write(priv->rm_fields[F_OPMODE], 0);
 492 }
 493
 494 static bool rtq6056_is_readable_reg(struct device *dev, unsigned int reg)
 495 {
 496         switch (reg) {
 497         case RTQ6056_REG_CONFIG ... RTQ6056_REG_ALERTLIMIT:
 498         case RTQ6056_REG_MANUFACTID ... RTQ6056_REG_DIEID:
 499                 return true;
 500         default:
 501                 return false;
 502         }
 503 }
 504
 505 static bool rtq6056_is_writeable_reg(struct device *dev, unsigned int reg)
 506 {
 507         switch (reg) {
 508         case RTQ6056_REG_CONFIG:
 509         case RTQ6056_REG_CALIBRATION ... RTQ6056_REG_ALERTLIMIT:
 510                 return true;
 511         default:
 512                 return false;
 513         }
 514 }
 515
 516 static const struct regmap_config rtq6056_regmap_config = {
 517         .reg_bits = 8,
 518         .val_bits = 16,
 519         .val_format_endian = REGMAP_ENDIAN_BIG,
 520         .max_register = RTQ6056_REG_DIEID,
 521         .readable_reg = rtq6056_is_readable_reg,
 522         .writeable_reg = rtq6056_is_writeable_reg,
 523 };
 524
 525 static int rtq6056_probe(struct i2c_client *i2c)
 526 {
 527         struct iio_dev *indio_dev;
 528         struct rtq6056_priv *priv;
 529         struct device *dev = &i2c->dev;
 530         struct regmap *regmap;
 531         unsigned int vendor_id, shunt_resistor_uohm;
 532         int ret;
 533
 534         if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_WORD_DATA))
 535                 return -EOPNOTSUPP;
 536
 537         indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
 538         if (!indio_dev)
 539                 return -ENOMEM;
 540
 541         priv = iio_priv(indio_dev);
 542         priv->dev = dev;
 543         priv->vshuntct_us = priv->vbusct_us = 1037;
 544         priv->avg_sample = 1;
 545         i2c_set_clientdata(i2c, priv);
 546
 547         regmap = devm_regmap_init_i2c(i2c, &rtq6056_regmap_config);
 548         if (IS_ERR(regmap))
 549                 return dev_err_probe(dev, PTR_ERR(regmap),
 550                                      "Failed to init regmap\n");
 551
 552         priv->regmap = regmap;
 553
 554         ret = regmap_read(regmap, RTQ6056_REG_MANUFACTID, &vendor_id);
 555         if (ret)
 556                 return dev_err_probe(dev, ret,
 557                                      "Failed to get manufacturer info\n");
 558
 559         if (vendor_id != RTQ6056_VENDOR_ID)
 560                 return dev_err_probe(dev, -ENODEV,
 561                                      "Invalid vendor id 0x%04x\n", vendor_id);
 562
 563         ret = devm_regmap_field_bulk_alloc(dev, regmap, priv->rm_fields,
 564                                            rtq6056_reg_fields, F_MAX_FIELDS);
 565         if (ret)
 566                 return dev_err_probe(dev, ret, "Failed to init regmap field\n");
 567
 568         /*
 569          * By default, configure average sample as 1, bus and shunt conversion
 570          * time as 1037 microsecond, and operating mode to all on.
 571          */
 572         ret = regmap_write(regmap, RTQ6056_REG_CONFIG, RTQ6056_DEFAULT_CONFIG);
 573         if (ret)
 574                 return dev_err_probe(dev, ret,
 575                                      "Failed to enable continuous sensing\n");
 576
 577         ret = devm_add_action_or_reset(dev, rtq6056_enter_shutdown_state, dev);
 578         if (ret)
 579                 return ret;
 580
 581         pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC);
 582         pm_runtime_use_autosuspend(dev);
 583         pm_runtime_set_active(dev);
 584         pm_runtime_mark_last_busy(dev);
 585         ret = devm_pm_runtime_enable(dev);
 586         if (ret)
 587                 return dev_err_probe(dev, ret, "Failed to enable pm_runtime\n");
 588
 589         /* By default, use 2000 micro-Ohm resistor */
 590         shunt_resistor_uohm = 2000;
 591         device_property_read_u32(dev, "shunt-resistor-micro-ohms",
 592                                  &shunt_resistor_uohm);
 593
 594         ret = rtq6056_set_shunt_resistor(priv, shunt_resistor_uohm);
 595         if (ret)
 596                 return dev_err_probe(dev, ret,
 597                                      "Failed to init shunt resistor\n");
 598
 599         indio_dev->name = "rtq6056";
 600         indio_dev->modes = INDIO_DIRECT_MODE;
 601         indio_dev->channels = rtq6056_channels;
 602         indio_dev->num_channels = ARRAY_SIZE(rtq6056_channels);
 603         indio_dev->info = &rtq6056_info;
 604
 605         ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
 606                                               rtq6056_buffer_trigger_handler,
 607                                               NULL);
 608         if (ret)
 609                 return dev_err_probe(dev, ret,
 610                                      "Failed to allocate iio trigger buffer\n");
 611
 612         return devm_iio_device_register(dev, indio_dev);
 613 }
 614
 615 static int rtq6056_runtime_suspend(struct device *dev)
 616 {
 617         struct rtq6056_priv *priv = dev_get_drvdata(dev);
 618
 619         /* Configure to shutdown mode */
 620         return regmap_field_write(priv->rm_fields[F_OPMODE], 0);
 621 }
 622
 623 static int rtq6056_runtime_resume(struct device *dev)
 624 {
 625         struct rtq6056_priv *priv = dev_get_drvdata(dev);
 626         int sample_rdy_time_us, ret;
 627
 628         ret = regmap_field_write(priv->rm_fields[F_OPMODE], RTQ6056_CONT_ALLON);
 629         if (ret)
 630                 return ret;
 631
 632         sample_rdy_time_us = priv->vbusct_us + priv->vshuntct_us;
 633         sample_rdy_time_us *= priv->avg_sample;
 634
 635         usleep_range(sample_rdy_time_us, sample_rdy_time_us + 100);
 636
 637         return 0;
 638 }
 639
 640 static DEFINE_RUNTIME_DEV_PM_OPS(rtq6056_pm_ops, rtq6056_runtime_suspend,
 641                                  rtq6056_runtime_resume, NULL);
 642
 643 static const struct of_device_id rtq6056_device_match[] = {
 644         { .compatible = "richtek,rtq6056" },
 645         {}
 646 };
 647 MODULE_DEVICE_TABLE(of, rtq6056_device_match);
 648
 649 static struct i2c_driver rtq6056_driver = {
 650         .driver = {
 651                 .name = "rtq6056",
 652                 .of_match_table = rtq6056_device_match,
 653                 .pm = pm_ptr(&rtq6056_pm_ops),
 654         },
 655         .probe = rtq6056_probe,
 656 };
 657 module_i2c_driver(rtq6056_driver);
 658
 659 MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
 660 MODULE_DESCRIPTION("Richtek RTQ6056 Driver");
 661 MODULE_LICENSE("GPL v2");