drivers/iio/adc/axp20x_adc.c

   1 /* ADC driver for AXP20X and AXP22X PMICs
   2  *
   3  * Copyright (c) 2016 Free Electrons NextThing Co.
   4  *      Quentin Schulz <quentin.schulz@free-electrons.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it under
   7  * the terms of the GNU General Public License version 2 as published by the
   8  * Free Software Foundation.
   9  */
  10
  11 #include <linux/completion.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/io.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/of_device.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/pm_runtime.h>
  19 #include <linux/regmap.h>
  20 #include <linux/thermal.h>
  21
  22 #include <linux/iio/iio.h>
  23 #include <linux/iio/driver.h>
  24 #include <linux/iio/machine.h>
  25 #include <linux/mfd/axp20x.h>
  26
  27 #define AXP20X_ADC_EN1_MASK                     GENMASK(7, 0)
  28
  29 #define AXP20X_ADC_EN2_MASK                     (GENMASK(3, 2) | BIT(7))
  30 #define AXP22X_ADC_EN1_MASK                     (GENMASK(7, 5) | BIT(0))
  31
  32 #define AXP20X_GPIO10_IN_RANGE_GPIO0            BIT(0)
  33 #define AXP20X_GPIO10_IN_RANGE_GPIO1            BIT(1)
  34 #define AXP20X_GPIO10_IN_RANGE_GPIO0_VAL(x)     ((x) & BIT(0))
  35 #define AXP20X_GPIO10_IN_RANGE_GPIO1_VAL(x)     (((x) & BIT(0)) << 1)
  36
  37 #define AXP20X_ADC_RATE_MASK                    GENMASK(7, 6)
  38 #define AXP20X_ADC_RATE_HZ(x)                   ((ilog2((x) / 25) << 6) & AXP20X_ADC_RATE_MASK)
  39 #define AXP22X_ADC_RATE_HZ(x)                   ((ilog2((x) / 100) << 6) & AXP20X_ADC_RATE_MASK)
  40
  41 #define AXP20X_ADC_CHANNEL(_channel, _name, _type, _reg)        \
  42         {                                                       \
  43                 .type = _type,                                  \
  44                 .indexed = 1,                                   \
  45                 .channel = _channel,                            \
  46                 .address = _reg,                                \
  47                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |  \
  48                                       BIT(IIO_CHAN_INFO_SCALE), \
  49                 .datasheet_name = _name,                        \
  50         }
  51
  52 #define AXP20X_ADC_CHANNEL_OFFSET(_channel, _name, _type, _reg) \
  53         {                                                       \
  54                 .type = _type,                                  \
  55                 .indexed = 1,                                   \
  56                 .channel = _channel,                            \
  57                 .address = _reg,                                \
  58                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |  \
  59                                       BIT(IIO_CHAN_INFO_SCALE) |\
  60                                       BIT(IIO_CHAN_INFO_OFFSET),\
  61                 .datasheet_name = _name,                        \
  62         }
  63
  64 struct axp_data;
  65
  66 struct axp20x_adc_iio {
  67         struct regmap           *regmap;
  68         struct axp_data         *data;
  69 };
  70
  71 enum axp20x_adc_channel_v {
  72         AXP20X_ACIN_V = 0,
  73         AXP20X_VBUS_V,
  74         AXP20X_TS_IN,
  75         AXP20X_GPIO0_V,
  76         AXP20X_GPIO1_V,
  77         AXP20X_IPSOUT_V,
  78         AXP20X_BATT_V,
  79 };
  80
  81 enum axp20x_adc_channel_i {
  82         AXP20X_ACIN_I = 0,
  83         AXP20X_VBUS_I,
  84         AXP20X_BATT_CHRG_I,
  85         AXP20X_BATT_DISCHRG_I,
  86 };
  87
  88 enum axp22x_adc_channel_v {
  89         AXP22X_TS_IN = 0,
  90         AXP22X_BATT_V,
  91 };
  92
  93 enum axp22x_adc_channel_i {
  94         AXP22X_BATT_CHRG_I = 1,
  95         AXP22X_BATT_DISCHRG_I,
  96 };
  97
  98 static struct iio_map axp20x_maps[] = {
  99         {
 100                 .consumer_dev_name = "axp20x-usb-power-supply",
 101                 .consumer_channel = "vbus_v",
 102                 .adc_channel_label = "vbus_v",
 103         }, {
 104                 .consumer_dev_name = "axp20x-usb-power-supply",
 105                 .consumer_channel = "vbus_i",
 106                 .adc_channel_label = "vbus_i",
 107         }, {
 108                 .consumer_dev_name = "axp20x-ac-power-supply",
 109                 .consumer_channel = "acin_v",
 110                 .adc_channel_label = "acin_v",
 111         }, {
 112                 .consumer_dev_name = "axp20x-ac-power-supply",
 113                 .consumer_channel = "acin_i",
 114                 .adc_channel_label = "acin_i",
 115         }, {
 116                 .consumer_dev_name = "axp20x-battery-power-supply",
 117                 .consumer_channel = "batt_v",
 118                 .adc_channel_label = "batt_v",
 119         }, {
 120                 .consumer_dev_name = "axp20x-battery-power-supply",
 121                 .consumer_channel = "batt_chrg_i",
 122                 .adc_channel_label = "batt_chrg_i",
 123         }, {
 124                 .consumer_dev_name = "axp20x-battery-power-supply",
 125                 .consumer_channel = "batt_dischrg_i",
 126                 .adc_channel_label = "batt_dischrg_i",
 127         }, { /* sentinel */ }
 128 };
 129
 130 static struct iio_map axp22x_maps[] = {
 131         {
 132                 .consumer_dev_name = "axp20x-battery-power-supply",
 133                 .consumer_channel = "batt_v",
 134                 .adc_channel_label = "batt_v",
 135         }, {
 136                 .consumer_dev_name = "axp20x-battery-power-supply",
 137                 .consumer_channel = "batt_chrg_i",
 138                 .adc_channel_label = "batt_chrg_i",
 139         }, {
 140                 .consumer_dev_name = "axp20x-battery-power-supply",
 141                 .consumer_channel = "batt_dischrg_i",
 142                 .adc_channel_label = "batt_dischrg_i",
 143         }, { /* sentinel */ }
 144 };
 145
 146 /*
 147  * Channels are mapped by physical system. Their channels share the same index.
 148  * i.e. acin_i is in_current0_raw and acin_v is in_voltage0_raw.
 149  * The only exception is for the battery. batt_v will be in_voltage6_raw and
 150  * charge current in_current6_raw and discharge current will be in_current7_raw.
 151  */
 152 static const struct iio_chan_spec axp20x_adc_channels[] = {
 153         AXP20X_ADC_CHANNEL(AXP20X_ACIN_V, "acin_v", IIO_VOLTAGE,
 154                            AXP20X_ACIN_V_ADC_H),
 155         AXP20X_ADC_CHANNEL(AXP20X_ACIN_I, "acin_i", IIO_CURRENT,
 156                            AXP20X_ACIN_I_ADC_H),
 157         AXP20X_ADC_CHANNEL(AXP20X_VBUS_V, "vbus_v", IIO_VOLTAGE,
 158                            AXP20X_VBUS_V_ADC_H),
 159         AXP20X_ADC_CHANNEL(AXP20X_VBUS_I, "vbus_i", IIO_CURRENT,
 160                            AXP20X_VBUS_I_ADC_H),
 161         {
 162                 .type = IIO_TEMP,
 163                 .address = AXP20X_TEMP_ADC_H,
 164                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 165                                       BIT(IIO_CHAN_INFO_SCALE) |
 166                                       BIT(IIO_CHAN_INFO_OFFSET),
 167                 .datasheet_name = "pmic_temp",
 168         },
 169         AXP20X_ADC_CHANNEL_OFFSET(AXP20X_GPIO0_V, "gpio0_v", IIO_VOLTAGE,
 170                                   AXP20X_GPIO0_V_ADC_H),
 171         AXP20X_ADC_CHANNEL_OFFSET(AXP20X_GPIO1_V, "gpio1_v", IIO_VOLTAGE,
 172                                   AXP20X_GPIO1_V_ADC_H),
 173         AXP20X_ADC_CHANNEL(AXP20X_IPSOUT_V, "ipsout_v", IIO_VOLTAGE,
 174                            AXP20X_IPSOUT_V_HIGH_H),
 175         AXP20X_ADC_CHANNEL(AXP20X_BATT_V, "batt_v", IIO_VOLTAGE,
 176                            AXP20X_BATT_V_H),
 177         AXP20X_ADC_CHANNEL(AXP20X_BATT_CHRG_I, "batt_chrg_i", IIO_CURRENT,
 178                            AXP20X_BATT_CHRG_I_H),
 179         AXP20X_ADC_CHANNEL(AXP20X_BATT_DISCHRG_I, "batt_dischrg_i", IIO_CURRENT,
 180                            AXP20X_BATT_DISCHRG_I_H),
 181 };
 182
 183 static const struct iio_chan_spec axp22x_adc_channels[] = {
 184         {
 185                 .type = IIO_TEMP,
 186                 .address = AXP22X_PMIC_TEMP_H,
 187                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 188                                       BIT(IIO_CHAN_INFO_SCALE) |
 189                                       BIT(IIO_CHAN_INFO_OFFSET),
 190                 .datasheet_name = "pmic_temp",
 191         },
 192         AXP20X_ADC_CHANNEL(AXP22X_BATT_V, "batt_v", IIO_VOLTAGE,
 193                            AXP20X_BATT_V_H),
 194         AXP20X_ADC_CHANNEL(AXP22X_BATT_CHRG_I, "batt_chrg_i", IIO_CURRENT,
 195                            AXP20X_BATT_CHRG_I_H),
 196         AXP20X_ADC_CHANNEL(AXP22X_BATT_DISCHRG_I, "batt_dischrg_i", IIO_CURRENT,
 197                            AXP20X_BATT_DISCHRG_I_H),
 198 };
 199
 200 static int axp20x_adc_raw(struct iio_dev *indio_dev,
 201                           struct iio_chan_spec const *chan, int *val)
 202 {
 203         struct axp20x_adc_iio *info = iio_priv(indio_dev);
 204         int size = 12;
 205
 206         /*
 207          * N.B.:  Unlike the Chinese datasheets tell, the charging current is
 208          * stored on 12 bits, not 13 bits. Only discharging current is on 13
 209          * bits.
 210          */
 211         if (chan->type == IIO_CURRENT && chan->channel == AXP20X_BATT_DISCHRG_I)
 212                 size = 13;
 213         else
 214                 size = 12;
 215
 216         *val = axp20x_read_variable_width(info->regmap, chan->address, size);
 217         if (*val < 0)
 218                 return *val;
 219
 220         return IIO_VAL_INT;
 221 }
 222
 223 static int axp22x_adc_raw(struct iio_dev *indio_dev,
 224                           struct iio_chan_spec const *chan, int *val)
 225 {
 226         struct axp20x_adc_iio *info = iio_priv(indio_dev);
 227         int size;
 228
 229         /*
 230          * N.B.: Unlike the Chinese datasheets tell, the charging current is
 231          * stored on 12 bits, not 13 bits. Only discharging current is on 13
 232          * bits.
 233          */
 234         if (chan->type == IIO_CURRENT && chan->channel == AXP22X_BATT_DISCHRG_I)
 235                 size = 13;
 236         else
 237                 size = 12;
 238
 239         *val = axp20x_read_variable_width(info->regmap, chan->address, size);
 240         if (*val < 0)
 241                 return *val;
 242
 243         return IIO_VAL_INT;
 244 }
 245
 246 static int axp20x_adc_scale_voltage(int channel, int *val, int *val2)
 247 {
 248         switch (channel) {
 249         case AXP20X_ACIN_V:
 250         case AXP20X_VBUS_V:
 251                 *val = 1;
 252                 *val2 = 700000;
 253                 return IIO_VAL_INT_PLUS_MICRO;
 254
 255         case AXP20X_GPIO0_V:
 256         case AXP20X_GPIO1_V:
 257                 *val = 0;
 258                 *val2 = 500000;
 259                 return IIO_VAL_INT_PLUS_MICRO;
 260
 261         case AXP20X_BATT_V:
 262                 *val = 1;
 263                 *val2 = 100000;
 264                 return IIO_VAL_INT_PLUS_MICRO;
 265
 266         case AXP20X_IPSOUT_V:
 267                 *val = 1;
 268                 *val2 = 400000;
 269                 return IIO_VAL_INT_PLUS_MICRO;
 270
 271         default:
 272                 return -EINVAL;
 273         }
 274 }
 275
 276 static int axp20x_adc_scale_current(int channel, int *val, int *val2)
 277 {
 278         switch (channel) {
 279         case AXP20X_ACIN_I:
 280                 *val = 0;
 281                 *val2 = 625000;
 282                 return IIO_VAL_INT_PLUS_MICRO;
 283
 284         case AXP20X_VBUS_I:
 285                 *val = 0;
 286                 *val2 = 375000;
 287                 return IIO_VAL_INT_PLUS_MICRO;
 288
 289         case AXP20X_BATT_DISCHRG_I:
 290         case AXP20X_BATT_CHRG_I:
 291                 *val = 0;
 292                 *val2 = 500000;
 293                 return IIO_VAL_INT_PLUS_MICRO;
 294
 295         default:
 296                 return -EINVAL;
 297         }
 298 }
 299
 300 static int axp20x_adc_scale(struct iio_chan_spec const *chan, int *val,
 301                             int *val2)
 302 {
 303         switch (chan->type) {
 304         case IIO_VOLTAGE:
 305                 return axp20x_adc_scale_voltage(chan->channel, val, val2);
 306
 307         case IIO_CURRENT:
 308                 return axp20x_adc_scale_current(chan->channel, val, val2);
 309
 310         case IIO_TEMP:
 311                 *val = 100;
 312                 return IIO_VAL_INT;
 313
 314         default:
 315                 return -EINVAL;
 316         }
 317 }
 318
 319 static int axp22x_adc_scale(struct iio_chan_spec const *chan, int *val,
 320                             int *val2)
 321 {
 322         switch (chan->type) {
 323         case IIO_VOLTAGE:
 324                 if (chan->channel != AXP22X_BATT_V)
 325                         return -EINVAL;
 326
 327                 *val = 1;
 328                 *val2 = 100000;
 329                 return IIO_VAL_INT_PLUS_MICRO;
 330
 331         case IIO_CURRENT:
 332                 *val = 0;
 333                 *val2 = 500000;
 334                 return IIO_VAL_INT_PLUS_MICRO;
 335
 336         case IIO_TEMP:
 337                 *val = 100;
 338                 return IIO_VAL_INT;
 339
 340         default:
 341                 return -EINVAL;
 342         }
 343 }
 344
 345 static int axp20x_adc_offset_voltage(struct iio_dev *indio_dev, int channel,
 346                                      int *val)
 347 {
 348         struct axp20x_adc_iio *info = iio_priv(indio_dev);
 349         int ret;
 350
 351         ret = regmap_read(info->regmap, AXP20X_GPIO10_IN_RANGE, val);
 352         if (ret < 0)
 353                 return ret;
 354
 355         switch (channel) {
 356         case AXP20X_GPIO0_V:
 357                 *val &= AXP20X_GPIO10_IN_RANGE_GPIO0;
 358                 break;
 359
 360         case AXP20X_GPIO1_V:
 361                 *val &= AXP20X_GPIO10_IN_RANGE_GPIO1;
 362                 break;
 363
 364         default:
 365                 return -EINVAL;
 366         }
 367
 368         *val = !!(*val) * 700000;
 369
 370         return IIO_VAL_INT;
 371 }
 372
 373 static int axp20x_adc_offset(struct iio_dev *indio_dev,
 374                              struct iio_chan_spec const *chan, int *val)
 375 {
 376         switch (chan->type) {
 377         case IIO_VOLTAGE:
 378                 return axp20x_adc_offset_voltage(indio_dev, chan->channel, val);
 379
 380         case IIO_TEMP:
 381                 *val = -1447;
 382                 return IIO_VAL_INT;
 383
 384         default:
 385                 return -EINVAL;
 386         }
 387 }
 388
 389 static int axp20x_read_raw(struct iio_dev *indio_dev,
 390                            struct iio_chan_spec const *chan, int *val,
 391                            int *val2, long mask)
 392 {
 393         switch (mask) {
 394         case IIO_CHAN_INFO_OFFSET:
 395                 return axp20x_adc_offset(indio_dev, chan, val);
 396
 397         case IIO_CHAN_INFO_SCALE:
 398                 return axp20x_adc_scale(chan, val, val2);
 399
 400         case IIO_CHAN_INFO_RAW:
 401                 return axp20x_adc_raw(indio_dev, chan, val);
 402
 403         default:
 404                 return -EINVAL;
 405         }
 406 }
 407
 408 static int axp22x_read_raw(struct iio_dev *indio_dev,
 409                            struct iio_chan_spec const *chan, int *val,
 410                            int *val2, long mask)
 411 {
 412         switch (mask) {
 413         case IIO_CHAN_INFO_OFFSET:
 414                 *val = -2677;
 415                 return IIO_VAL_INT;
 416
 417         case IIO_CHAN_INFO_SCALE:
 418                 return axp22x_adc_scale(chan, val, val2);
 419
 420         case IIO_CHAN_INFO_RAW:
 421                 return axp22x_adc_raw(indio_dev, chan, val);
 422
 423         default:
 424                 return -EINVAL;
 425         }
 426 }
 427
 428 static int axp20x_write_raw(struct iio_dev *indio_dev,
 429                             struct iio_chan_spec const *chan, int val, int val2,
 430                             long mask)
 431 {
 432         struct axp20x_adc_iio *info = iio_priv(indio_dev);
 433         unsigned int reg, regval;
 434
 435         /*
 436          * The AXP20X PMIC allows the user to choose between 0V and 0.7V offsets
 437          * for (independently) GPIO0 and GPIO1 when in ADC mode.
 438          */
 439         if (mask != IIO_CHAN_INFO_OFFSET)
 440                 return -EINVAL;
 441
 442         if (val != 0 && val != 700000)
 443                 return -EINVAL;
 444
 445         switch (chan->channel) {
 446         case AXP20X_GPIO0_V:
 447                 reg = AXP20X_GPIO10_IN_RANGE_GPIO0;
 448                 regval = AXP20X_GPIO10_IN_RANGE_GPIO0_VAL(!!val);
 449                 break;
 450
 451         case AXP20X_GPIO1_V:
 452                 reg = AXP20X_GPIO10_IN_RANGE_GPIO1;
 453                 regval = AXP20X_GPIO10_IN_RANGE_GPIO1_VAL(!!val);
 454                 break;
 455
 456         default:
 457                 return -EINVAL;
 458         }
 459
 460         return regmap_update_bits(info->regmap, AXP20X_GPIO10_IN_RANGE, reg,
 461                                   regval);
 462 }
 463
 464 static const struct iio_info axp20x_adc_iio_info = {
 465         .read_raw = axp20x_read_raw,
 466         .write_raw = axp20x_write_raw,
 467 };
 468
 469 static const struct iio_info axp22x_adc_iio_info = {
 470         .read_raw = axp22x_read_raw,
 471 };
 472
 473 static int axp20x_adc_rate(int rate)
 474 {
 475         return AXP20X_ADC_RATE_HZ(rate);
 476 }
 477
 478 static int axp22x_adc_rate(int rate)
 479 {
 480         return AXP22X_ADC_RATE_HZ(rate);
 481 }
 482
 483 struct axp_data {
 484         const struct iio_info           *iio_info;
 485         int                             num_channels;
 486         struct iio_chan_spec const      *channels;
 487         unsigned long                   adc_en1_mask;
 488         int                             (*adc_rate)(int rate);
 489         bool                            adc_en2;
 490         struct iio_map                  *maps;
 491 };
 492
 493 static const struct axp_data axp20x_data = {
 494         .iio_info = &axp20x_adc_iio_info,
 495         .num_channels = ARRAY_SIZE(axp20x_adc_channels),
 496         .channels = axp20x_adc_channels,
 497         .adc_en1_mask = AXP20X_ADC_EN1_MASK,
 498         .adc_rate = axp20x_adc_rate,
 499         .adc_en2 = true,
 500         .maps = axp20x_maps,
 501 };
 502
 503 static const struct axp_data axp22x_data = {
 504         .iio_info = &axp22x_adc_iio_info,
 505         .num_channels = ARRAY_SIZE(axp22x_adc_channels),
 506         .channels = axp22x_adc_channels,
 507         .adc_en1_mask = AXP22X_ADC_EN1_MASK,
 508         .adc_rate = axp22x_adc_rate,
 509         .adc_en2 = false,
 510         .maps = axp22x_maps,
 511 };
 512
 513 static const struct platform_device_id axp20x_adc_id_match[] = {
 514         { .name = "axp20x-adc", .driver_data = (kernel_ulong_t)&axp20x_data, },
 515         { .name = "axp22x-adc", .driver_data = (kernel_ulong_t)&axp22x_data, },
 516         { /* sentinel */ },
 517 };
 518 MODULE_DEVICE_TABLE(platform, axp20x_adc_id_match);
 519
 520 static int axp20x_probe(struct platform_device *pdev)
 521 {
 522         struct axp20x_adc_iio *info;
 523         struct iio_dev *indio_dev;
 524         struct axp20x_dev *axp20x_dev;
 525         int ret;
 526
 527         axp20x_dev = dev_get_drvdata(pdev->dev.parent);
 528
 529         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
 530         if (!indio_dev)
 531                 return -ENOMEM;
 532
 533         info = iio_priv(indio_dev);
 534         platform_set_drvdata(pdev, indio_dev);
 535
 536         info->regmap = axp20x_dev->regmap;
 537         indio_dev->dev.parent = &pdev->dev;
 538         indio_dev->dev.of_node = pdev->dev.of_node;
 539         indio_dev->modes = INDIO_DIRECT_MODE;
 540
 541         info->data = (struct axp_data *)platform_get_device_id(pdev)->driver_data;
 542
 543         indio_dev->name = platform_get_device_id(pdev)->name;
 544         indio_dev->info = info->data->iio_info;
 545         indio_dev->num_channels = info->data->num_channels;
 546         indio_dev->channels = info->data->channels;
 547
 548         /* Enable the ADCs on IP */
 549         regmap_write(info->regmap, AXP20X_ADC_EN1, info->data->adc_en1_mask);
 550
 551         if (info->data->adc_en2)
 552                 /* Enable GPIO0/1 and internal temperature ADCs */
 553                 regmap_update_bits(info->regmap, AXP20X_ADC_EN2,
 554                                    AXP20X_ADC_EN2_MASK, AXP20X_ADC_EN2_MASK);
 555
 556         /* Configure ADCs rate */
 557         regmap_update_bits(info->regmap, AXP20X_ADC_RATE, AXP20X_ADC_RATE_MASK,
 558                            info->data->adc_rate(100));
 559
 560         ret = iio_map_array_register(indio_dev, info->data->maps);
 561         if (ret < 0) {
 562                 dev_err(&pdev->dev, "failed to register IIO maps: %d\n", ret);
 563                 goto fail_map;
 564         }
 565
 566         ret = iio_device_register(indio_dev);
 567         if (ret < 0) {
 568                 dev_err(&pdev->dev, "could not register the device\n");
 569                 goto fail_register;
 570         }
 571
 572         return 0;
 573
 574 fail_register:
 575         iio_map_array_unregister(indio_dev);
 576
 577 fail_map:
 578         regmap_write(info->regmap, AXP20X_ADC_EN1, 0);
 579
 580         if (info->data->adc_en2)
 581                 regmap_write(info->regmap, AXP20X_ADC_EN2, 0);
 582
 583         return ret;
 584 }
 585
 586 static int axp20x_remove(struct platform_device *pdev)
 587 {
 588         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 589         struct axp20x_adc_iio *info = iio_priv(indio_dev);
 590
 591         iio_device_unregister(indio_dev);
 592         iio_map_array_unregister(indio_dev);
 593
 594         regmap_write(info->regmap, AXP20X_ADC_EN1, 0);
 595
 596         if (info->data->adc_en2)
 597                 regmap_write(info->regmap, AXP20X_ADC_EN2, 0);
 598
 599         return 0;
 600 }
 601
 602 static struct platform_driver axp20x_adc_driver = {
 603         .driver = {
 604                 .name = "axp20x-adc",
 605         },
 606         .id_table = axp20x_adc_id_match,
 607         .probe = axp20x_probe,
 608         .remove = axp20x_remove,
 609 };
 610
 611 module_platform_driver(axp20x_adc_driver);
 612
 613 MODULE_DESCRIPTION("ADC driver for AXP20X and AXP22X PMICs");
 614 MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
 615 MODULE_LICENSE("GPL");