root/drivers/iio/adc/sun4i-gpadc-iio.c

DEFINITIONS

1. sun4i_gpadc_chan_select
2. sun6i_gpadc_chan_select
3. sun4i_prepare_for_irq
4. sun4i_gpadc_read
5. sun4i_gpadc_adc_read
6. sun4i_gpadc_temp_read
7. sun4i_gpadc_temp_offset
8. sun4i_gpadc_temp_scale
9. sun4i_gpadc_read_raw
10. sun4i_gpadc_temp_data_irq_handler
11. sun4i_gpadc_fifo_data_irq_handler
12. sun4i_gpadc_runtime_suspend
13. sun4i_gpadc_runtime_resume
14. sun4i_gpadc_get_temp
15. sun4i_irq_init
16. sun4i_gpadc_probe_dt
17. sun4i_gpadc_probe_mfd
18. sun4i_gpadc_probe
19. sun4i_gpadc_remove

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* ADC driver for sunxi platforms' (A10, A13 and A31) GPADC
   3  *
   4  * Copyright (c) 2016 Quentin Schulz <quentin.schulz@free-electrons.com>
   5  *
   6  * The Allwinner SoCs all have an ADC that can also act as a touchscreen
   7  * controller and a thermal sensor.
   8  * The thermal sensor works only when the ADC acts as a touchscreen controller
   9  * and is configured to throw an interrupt every fixed periods of time (let say
  10  * every X seconds).
  11  * One would be tempted to disable the IP on the hardware side rather than
  12  * disabling interrupts to save some power but that resets the internal clock of
  13  * the IP, resulting in having to wait X seconds every time we want to read the
  14  * value of the thermal sensor.
  15  * This is also the reason of using autosuspend in pm_runtime. If there was no
  16  * autosuspend, the thermal sensor would need X seconds after every
  17  * pm_runtime_get_sync to get a value from the ADC. The autosuspend allows the
  18  * thermal sensor to be requested again in a certain time span before it gets
  19  * shutdown for not being used.
  20  */
  21 
  22 #include <linux/completion.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/io.h>
  25 #include <linux/module.h>
  26 #include <linux/of.h>
  27 #include <linux/of_device.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/pm_runtime.h>
  30 #include <linux/regmap.h>
  31 #include <linux/thermal.h>
  32 #include <linux/delay.h>
  33 
  34 #include <linux/iio/iio.h>
  35 #include <linux/iio/driver.h>
  36 #include <linux/iio/machine.h>
  37 #include <linux/mfd/sun4i-gpadc.h>
  38 
  39 static unsigned int sun4i_gpadc_chan_select(unsigned int chan)
  40 {
  41         return SUN4I_GPADC_CTRL1_ADC_CHAN_SELECT(chan);
  42 }
  43 
  44 static unsigned int sun6i_gpadc_chan_select(unsigned int chan)
  45 {
  46         return SUN6I_GPADC_CTRL1_ADC_CHAN_SELECT(chan);
  47 }
  48 
  49 struct gpadc_data {
  50         int             temp_offset;
  51         int             temp_scale;
  52         unsigned int    tp_mode_en;
  53         unsigned int    tp_adc_select;
  54         unsigned int    (*adc_chan_select)(unsigned int chan);
  55         unsigned int    adc_chan_mask;
  56 };
  57 
  58 static const struct gpadc_data sun4i_gpadc_data = {
  59         .temp_offset = -1932,
  60         .temp_scale = 133,
  61         .tp_mode_en = SUN4I_GPADC_CTRL1_TP_MODE_EN,
  62         .tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
  63         .adc_chan_select = &sun4i_gpadc_chan_select,
  64         .adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
  65 };
  66 
  67 static const struct gpadc_data sun5i_gpadc_data = {
  68         .temp_offset = -1447,
  69         .temp_scale = 100,
  70         .tp_mode_en = SUN4I_GPADC_CTRL1_TP_MODE_EN,
  71         .tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
  72         .adc_chan_select = &sun4i_gpadc_chan_select,
  73         .adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
  74 };
  75 
  76 static const struct gpadc_data sun6i_gpadc_data = {
  77         .temp_offset = -1623,
  78         .temp_scale = 167,
  79         .tp_mode_en = SUN6I_GPADC_CTRL1_TP_MODE_EN,
  80         .tp_adc_select = SUN6I_GPADC_CTRL1_TP_ADC_SELECT,
  81         .adc_chan_select = &sun6i_gpadc_chan_select,
  82         .adc_chan_mask = SUN6I_GPADC_CTRL1_ADC_CHAN_MASK,
  83 };
  84 
  85 static const struct gpadc_data sun8i_a33_gpadc_data = {
  86         .temp_offset = -1662,
  87         .temp_scale = 162,
  88         .tp_mode_en = SUN8I_GPADC_CTRL1_CHOP_TEMP_EN,
  89 };
  90 
  91 struct sun4i_gpadc_iio {
  92         struct iio_dev                  *indio_dev;
  93         struct completion               completion;
  94         int                             temp_data;
  95         u32                             adc_data;
  96         struct regmap                   *regmap;
  97         unsigned int                    fifo_data_irq;
  98         atomic_t                        ignore_fifo_data_irq;
  99         unsigned int                    temp_data_irq;
 100         atomic_t                        ignore_temp_data_irq;
 101         const struct gpadc_data         *data;
 102         bool                            no_irq;
 103         /* prevents concurrent reads of temperature and ADC */
 104         struct mutex                    mutex;
 105         struct thermal_zone_device      *tzd;
 106         struct device                   *sensor_device;
 107 };
 108 
 109 #define SUN4I_GPADC_ADC_CHANNEL(_channel, _name) {              \
 110         .type = IIO_VOLTAGE,                                    \
 111         .indexed = 1,                                           \
 112         .channel = _channel,                                    \
 113         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
 114         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
 115         .datasheet_name = _name,                                \
 116 }
 117 
 118 static struct iio_map sun4i_gpadc_hwmon_maps[] = {
 119         {
 120                 .adc_channel_label = "temp_adc",
 121                 .consumer_dev_name = "iio_hwmon.0",
 122         },
 123         { /* sentinel */ },
 124 };
 125 
 126 static const struct iio_chan_spec sun4i_gpadc_channels[] = {
 127         SUN4I_GPADC_ADC_CHANNEL(0, "adc_chan0"),
 128         SUN4I_GPADC_ADC_CHANNEL(1, "adc_chan1"),
 129         SUN4I_GPADC_ADC_CHANNEL(2, "adc_chan2"),
 130         SUN4I_GPADC_ADC_CHANNEL(3, "adc_chan3"),
 131         {
 132                 .type = IIO_TEMP,
 133                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 134                                       BIT(IIO_CHAN_INFO_SCALE) |
 135                                       BIT(IIO_CHAN_INFO_OFFSET),
 136                 .datasheet_name = "temp_adc",
 137         },
 138 };
 139 
 140 static const struct iio_chan_spec sun4i_gpadc_channels_no_temp[] = {
 141         SUN4I_GPADC_ADC_CHANNEL(0, "adc_chan0"),
 142         SUN4I_GPADC_ADC_CHANNEL(1, "adc_chan1"),
 143         SUN4I_GPADC_ADC_CHANNEL(2, "adc_chan2"),
 144         SUN4I_GPADC_ADC_CHANNEL(3, "adc_chan3"),
 145 };
 146 
 147 static const struct iio_chan_spec sun8i_a33_gpadc_channels[] = {
 148         {
 149                 .type = IIO_TEMP,
 150                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 151                                       BIT(IIO_CHAN_INFO_SCALE) |
 152                                       BIT(IIO_CHAN_INFO_OFFSET),
 153                 .datasheet_name = "temp_adc",
 154         },
 155 };
 156 
 157 static const struct regmap_config sun4i_gpadc_regmap_config = {
 158         .reg_bits = 32,
 159         .val_bits = 32,
 160         .reg_stride = 4,
 161         .fast_io = true,
 162 };
 163 
 164 static int sun4i_prepare_for_irq(struct iio_dev *indio_dev, int channel,
 165                                  unsigned int irq)
 166 {
 167         struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
 168         int ret;
 169         u32 reg;
 170 
 171         pm_runtime_get_sync(indio_dev->dev.parent);
 172 
 173         reinit_completion(&info->completion);
 174 
 175         ret = regmap_write(info->regmap, SUN4I_GPADC_INT_FIFOC,
 176                            SUN4I_GPADC_INT_FIFOC_TP_FIFO_TRIG_LEVEL(1) |
 177                            SUN4I_GPADC_INT_FIFOC_TP_FIFO_FLUSH);
 178         if (ret)
 179                 return ret;
 180 
 181         ret = regmap_read(info->regmap, SUN4I_GPADC_CTRL1, &reg);
 182         if (ret)
 183                 return ret;
 184 
 185         if (irq == info->fifo_data_irq) {
 186                 ret = regmap_write(info->regmap, SUN4I_GPADC_CTRL1,
 187                                    info->data->tp_mode_en |
 188                                    info->data->tp_adc_select |
 189                                    info->data->adc_chan_select(channel));
 190                 /*
 191                  * When the IP changes channel, it needs a bit of time to get
 192                  * correct values.
 193                  */
 194                 if ((reg & info->data->adc_chan_mask) !=
 195                          info->data->adc_chan_select(channel))
 196                         mdelay(10);
 197 
 198         } else {
 199                 /*
 200                  * The temperature sensor returns valid data only when the ADC
 201                  * operates in touchscreen mode.
 202                  */
 203                 ret = regmap_write(info->regmap, SUN4I_GPADC_CTRL1,
 204                                    info->data->tp_mode_en);
 205         }
 206 
 207         if (ret)
 208                 return ret;
 209 
 210         /*
 211          * When the IP changes mode between ADC or touchscreen, it
 212          * needs a bit of time to get correct values.
 213          */
 214         if ((reg & info->data->tp_adc_select) != info->data->tp_adc_select)
 215                 mdelay(100);
 216 
 217         return 0;
 218 }
 219 
 220 static int sun4i_gpadc_read(struct iio_dev *indio_dev, int channel, int *val,
 221                             unsigned int irq)
 222 {
 223         struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
 224         int ret;
 225 
 226         mutex_lock(&info->mutex);
 227 
 228         ret = sun4i_prepare_for_irq(indio_dev, channel, irq);
 229         if (ret)
 230                 goto err;
 231 
 232         enable_irq(irq);
 233 
 234         /*
 235          * The temperature sensor throws an interruption periodically (currently
 236          * set at periods of ~0.6s in sun4i_gpadc_runtime_resume). A 1s delay
 237          * makes sure an interruption occurs in normal conditions. If it doesn't
 238          * occur, then there is a timeout.
 239          */
 240         if (!wait_for_completion_timeout(&info->completion,
 241                                          msecs_to_jiffies(1000))) {
 242                 ret = -ETIMEDOUT;
 243                 goto err;
 244         }
 245 
 246         if (irq == info->fifo_data_irq)
 247                 *val = info->adc_data;
 248         else
 249                 *val = info->temp_data;
 250 
 251         ret = 0;
 252         pm_runtime_mark_last_busy(indio_dev->dev.parent);
 253 
 254 err:
 255         pm_runtime_put_autosuspend(indio_dev->dev.parent);
 256         disable_irq(irq);
 257         mutex_unlock(&info->mutex);
 258 
 259         return ret;
 260 }
 261 
 262 static int sun4i_gpadc_adc_read(struct iio_dev *indio_dev, int channel,
 263                                 int *val)
 264 {
 265         struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
 266 
 267         return sun4i_gpadc_read(indio_dev, channel, val, info->fifo_data_irq);
 268 }
 269 
 270 static int sun4i_gpadc_temp_read(struct iio_dev *indio_dev, int *val)
 271 {
 272         struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
 273 
 274         if (info->no_irq) {
 275                 pm_runtime_get_sync(indio_dev->dev.parent);
 276 
 277                 regmap_read(info->regmap, SUN4I_GPADC_TEMP_DATA, val);
 278 
 279                 pm_runtime_mark_last_busy(indio_dev->dev.parent);
 280                 pm_runtime_put_autosuspend(indio_dev->dev.parent);
 281 
 282                 return 0;
 283         }
 284 
 285         return sun4i_gpadc_read(indio_dev, 0, val, info->temp_data_irq);
 286 }
 287 
 288 static int sun4i_gpadc_temp_offset(struct iio_dev *indio_dev, int *val)
 289 {
 290         struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
 291 
 292         *val = info->data->temp_offset;
 293 
 294         return 0;
 295 }
 296 
 297 static int sun4i_gpadc_temp_scale(struct iio_dev *indio_dev, int *val)
 298 {
 299         struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
 300 
 301         *val = info->data->temp_scale;
 302 
 303         return 0;
 304 }
 305 
 306 static int sun4i_gpadc_read_raw(struct iio_dev *indio_dev,
 307                                 struct iio_chan_spec const *chan, int *val,
 308                                 int *val2, long mask)
 309 {
 310         int ret;
 311 
 312         switch (mask) {
 313         case IIO_CHAN_INFO_OFFSET:
 314                 ret = sun4i_gpadc_temp_offset(indio_dev, val);
 315                 if (ret)
 316                         return ret;
 317 
 318                 return IIO_VAL_INT;
 319         case IIO_CHAN_INFO_RAW:
 320                 if (chan->type == IIO_VOLTAGE)
 321                         ret = sun4i_gpadc_adc_read(indio_dev, chan->channel,
 322                                                    val);
 323                 else
 324                         ret = sun4i_gpadc_temp_read(indio_dev, val);
 325 
 326                 if (ret)
 327                         return ret;
 328 
 329                 return IIO_VAL_INT;
 330         case IIO_CHAN_INFO_SCALE:
 331                 if (chan->type == IIO_VOLTAGE) {
 332                         /* 3000mV / 4096 * raw */
 333                         *val = 0;
 334                         *val2 = 732421875;
 335                         return IIO_VAL_INT_PLUS_NANO;
 336                 }
 337 
 338                 ret = sun4i_gpadc_temp_scale(indio_dev, val);
 339                 if (ret)
 340                         return ret;
 341 
 342                 return IIO_VAL_INT;
 343         default:
 344                 return -EINVAL;
 345         }
 346 
 347         return -EINVAL;
 348 }
 349 
 350 static const struct iio_info sun4i_gpadc_iio_info = {
 351         .read_raw = sun4i_gpadc_read_raw,
 352 };
 353 
 354 static irqreturn_t sun4i_gpadc_temp_data_irq_handler(int irq, void *dev_id)
 355 {
 356         struct sun4i_gpadc_iio *info = dev_id;
 357 
 358         if (atomic_read(&info->ignore_temp_data_irq))
 359                 goto out;
 360 
 361         if (!regmap_read(info->regmap, SUN4I_GPADC_TEMP_DATA, &info->temp_data))
 362                 complete(&info->completion);
 363 
 364 out:
 365         return IRQ_HANDLED;
 366 }
 367 
 368 static irqreturn_t sun4i_gpadc_fifo_data_irq_handler(int irq, void *dev_id)
 369 {
 370         struct sun4i_gpadc_iio *info = dev_id;
 371 
 372         if (atomic_read(&info->ignore_fifo_data_irq))
 373                 goto out;
 374 
 375         if (!regmap_read(info->regmap, SUN4I_GPADC_DATA, &info->adc_data))
 376                 complete(&info->completion);
 377 
 378 out:
 379         return IRQ_HANDLED;
 380 }
 381 
 382 static int sun4i_gpadc_runtime_suspend(struct device *dev)
 383 {
 384         struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev));
 385 
 386         /* Disable the ADC on IP */
 387         regmap_write(info->regmap, SUN4I_GPADC_CTRL1, 0);
 388         /* Disable temperature sensor on IP */
 389         regmap_write(info->regmap, SUN4I_GPADC_TPR, 0);
 390 
 391         return 0;
 392 }
 393 
 394 static int sun4i_gpadc_runtime_resume(struct device *dev)
 395 {
 396         struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev));
 397 
 398         /* clkin = 6MHz */
 399         regmap_write(info->regmap, SUN4I_GPADC_CTRL0,
 400                      SUN4I_GPADC_CTRL0_ADC_CLK_DIVIDER(2) |
 401                      SUN4I_GPADC_CTRL0_FS_DIV(7) |
 402                      SUN4I_GPADC_CTRL0_T_ACQ(63));
 403         regmap_write(info->regmap, SUN4I_GPADC_CTRL1, info->data->tp_mode_en);
 404         regmap_write(info->regmap, SUN4I_GPADC_CTRL3,
 405                      SUN4I_GPADC_CTRL3_FILTER_EN |
 406                      SUN4I_GPADC_CTRL3_FILTER_TYPE(1));
 407         /* period = SUN4I_GPADC_TPR_TEMP_PERIOD * 256 * 16 / clkin; ~0.6s */
 408         regmap_write(info->regmap, SUN4I_GPADC_TPR,
 409                      SUN4I_GPADC_TPR_TEMP_ENABLE |
 410                      SUN4I_GPADC_TPR_TEMP_PERIOD(800));
 411 
 412         return 0;
 413 }
 414 
 415 static int sun4i_gpadc_get_temp(void *data, int *temp)
 416 {
 417         struct sun4i_gpadc_iio *info = data;
 418         int val, scale, offset;
 419 
 420         if (sun4i_gpadc_temp_read(info->indio_dev, &val))
 421                 return -ETIMEDOUT;
 422 
 423         sun4i_gpadc_temp_scale(info->indio_dev, &scale);
 424         sun4i_gpadc_temp_offset(info->indio_dev, &offset);
 425 
 426         *temp = (val + offset) * scale;
 427 
 428         return 0;
 429 }
 430 
 431 static const struct thermal_zone_of_device_ops sun4i_ts_tz_ops = {
 432         .get_temp = &sun4i_gpadc_get_temp,
 433 };
 434 
 435 static const struct dev_pm_ops sun4i_gpadc_pm_ops = {
 436         .runtime_suspend = &sun4i_gpadc_runtime_suspend,
 437         .runtime_resume = &sun4i_gpadc_runtime_resume,
 438 };
 439 
 440 static int sun4i_irq_init(struct platform_device *pdev, const char *name,
 441                           irq_handler_t handler, const char *devname,
 442                           unsigned int *irq, atomic_t *atomic)
 443 {
 444         int ret;
 445         struct sun4i_gpadc_dev *mfd_dev = dev_get_drvdata(pdev->dev.parent);
 446         struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(&pdev->dev));
 447 
 448         /*
 449          * Once the interrupt is activated, the IP continuously performs
 450          * conversions thus throws interrupts. The interrupt is activated right
 451          * after being requested but we want to control when these interrupts
 452          * occur thus we disable it right after being requested. However, an
 453          * interrupt might occur between these two instructions and we have to
 454          * make sure that does not happen, by using atomic flags. We set the
 455          * flag before requesting the interrupt and unset it right after
 456          * disabling the interrupt. When an interrupt occurs between these two
 457          * instructions, reading the atomic flag will tell us to ignore the
 458          * interrupt.
 459          */
 460         atomic_set(atomic, 1);
 461 
 462         ret = platform_get_irq_byname(pdev, name);
 463         if (ret < 0)
 464                 return ret;
 465 
 466         ret = regmap_irq_get_virq(mfd_dev->regmap_irqc, ret);
 467         if (ret < 0) {
 468                 dev_err(&pdev->dev, "failed to get virq for irq %s\n", name);
 469                 return ret;
 470         }
 471 
 472         *irq = ret;
 473         ret = devm_request_any_context_irq(&pdev->dev, *irq, handler, 0,
 474                                            devname, info);
 475         if (ret < 0) {
 476                 dev_err(&pdev->dev, "could not request %s interrupt: %d\n",
 477                         name, ret);
 478                 return ret;
 479         }
 480 
 481         disable_irq(*irq);
 482         atomic_set(atomic, 0);
 483 
 484         return 0;
 485 }
 486 
 487 static const struct of_device_id sun4i_gpadc_of_id[] = {
 488         {
 489                 .compatible = "allwinner,sun8i-a33-ths",
 490                 .data = &sun8i_a33_gpadc_data,
 491         },
 492         { /* sentinel */ }
 493 };
 494 
 495 static int sun4i_gpadc_probe_dt(struct platform_device *pdev,
 496                                 struct iio_dev *indio_dev)
 497 {
 498         struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
 499         struct resource *mem;
 500         void __iomem *base;
 501         int ret;
 502 
 503         info->data = of_device_get_match_data(&pdev->dev);
 504         if (!info->data)
 505                 return -ENODEV;
 506 
 507         info->no_irq = true;
 508         indio_dev->num_channels = ARRAY_SIZE(sun8i_a33_gpadc_channels);
 509         indio_dev->channels = sun8i_a33_gpadc_channels;
 510 
 511         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 512         base = devm_ioremap_resource(&pdev->dev, mem);
 513         if (IS_ERR(base))
 514                 return PTR_ERR(base);
 515 
 516         info->regmap = devm_regmap_init_mmio(&pdev->dev, base,
 517                                              &sun4i_gpadc_regmap_config);
 518         if (IS_ERR(info->regmap)) {
 519                 ret = PTR_ERR(info->regmap);
 520                 dev_err(&pdev->dev, "failed to init regmap: %d\n", ret);
 521                 return ret;
 522         }
 523 
 524         if (IS_ENABLED(CONFIG_THERMAL_OF))
 525                 info->sensor_device = &pdev->dev;
 526 
 527         return 0;
 528 }
 529 
 530 static int sun4i_gpadc_probe_mfd(struct platform_device *pdev,
 531                                  struct iio_dev *indio_dev)
 532 {
 533         struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
 534         struct sun4i_gpadc_dev *sun4i_gpadc_dev =
 535                 dev_get_drvdata(pdev->dev.parent);
 536         int ret;
 537 
 538         info->no_irq = false;
 539         info->regmap = sun4i_gpadc_dev->regmap;
 540 
 541         indio_dev->num_channels = ARRAY_SIZE(sun4i_gpadc_channels);
 542         indio_dev->channels = sun4i_gpadc_channels;
 543 
 544         info->data = (struct gpadc_data *)platform_get_device_id(pdev)->driver_data;
 545 
 546         /*
 547          * Since the controller needs to be in touchscreen mode for its thermal
 548          * sensor to operate properly, and that switching between the two modes
 549          * needs a delay, always registering in the thermal framework will
 550          * significantly slow down the conversion rate of the ADCs.
 551          *
 552          * Therefore, instead of depending on THERMAL_OF in Kconfig, we only
 553          * register the sensor if that option is enabled, eventually leaving
 554          * that choice to the user.
 555          */
 556 
 557         if (IS_ENABLED(CONFIG_THERMAL_OF)) {
 558                 /*
 559                  * This driver is a child of an MFD which has a node in the DT
 560                  * but not its children, because of DT backward compatibility
 561                  * for A10, A13 and A31 SoCs. Therefore, the resulting devices
 562                  * of this driver do not have an of_node variable.
 563                  * However, its parent (the MFD driver) has an of_node variable
 564                  * and since devm_thermal_zone_of_sensor_register uses its first
 565                  * argument to match the phandle defined in the node of the
 566                  * thermal driver with the of_node of the device passed as first
 567                  * argument and the third argument to call ops from
 568                  * thermal_zone_of_device_ops, the solution is to use the parent
 569                  * device as first argument to match the phandle with its
 570                  * of_node, and the device from this driver as third argument to
 571                  * return the temperature.
 572                  */
 573                 info->sensor_device = pdev->dev.parent;
 574         } else {
 575                 indio_dev->num_channels =
 576                         ARRAY_SIZE(sun4i_gpadc_channels_no_temp);
 577                 indio_dev->channels = sun4i_gpadc_channels_no_temp;
 578         }
 579 
 580         if (IS_ENABLED(CONFIG_THERMAL_OF)) {
 581                 ret = sun4i_irq_init(pdev, "TEMP_DATA_PENDING",
 582                                      sun4i_gpadc_temp_data_irq_handler,
 583                                      "temp_data", &info->temp_data_irq,
 584                                      &info->ignore_temp_data_irq);
 585                 if (ret < 0)
 586                         return ret;
 587         }
 588 
 589         ret = sun4i_irq_init(pdev, "FIFO_DATA_PENDING",
 590                              sun4i_gpadc_fifo_data_irq_handler, "fifo_data",
 591                              &info->fifo_data_irq, &info->ignore_fifo_data_irq);
 592         if (ret < 0)
 593                 return ret;
 594 
 595         if (IS_ENABLED(CONFIG_THERMAL_OF)) {
 596                 ret = iio_map_array_register(indio_dev, sun4i_gpadc_hwmon_maps);
 597                 if (ret < 0) {
 598                         dev_err(&pdev->dev,
 599                                 "failed to register iio map array\n");
 600                         return ret;
 601                 }
 602         }
 603 
 604         return 0;
 605 }
 606 
 607 static int sun4i_gpadc_probe(struct platform_device *pdev)
 608 {
 609         struct sun4i_gpadc_iio *info;
 610         struct iio_dev *indio_dev;
 611         int ret;
 612 
 613         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
 614         if (!indio_dev)
 615                 return -ENOMEM;
 616 
 617         info = iio_priv(indio_dev);
 618         platform_set_drvdata(pdev, indio_dev);
 619 
 620         mutex_init(&info->mutex);
 621         info->indio_dev = indio_dev;
 622         init_completion(&info->completion);
 623         indio_dev->name = dev_name(&pdev->dev);
 624         indio_dev->dev.parent = &pdev->dev;
 625         indio_dev->dev.of_node = pdev->dev.of_node;
 626         indio_dev->info = &sun4i_gpadc_iio_info;
 627         indio_dev->modes = INDIO_DIRECT_MODE;
 628 
 629         if (pdev->dev.of_node)
 630                 ret = sun4i_gpadc_probe_dt(pdev, indio_dev);
 631         else
 632                 ret = sun4i_gpadc_probe_mfd(pdev, indio_dev);
 633 
 634         if (ret)
 635                 return ret;
 636 
 637         pm_runtime_set_autosuspend_delay(&pdev->dev,
 638                                          SUN4I_GPADC_AUTOSUSPEND_DELAY);
 639         pm_runtime_use_autosuspend(&pdev->dev);
 640         pm_runtime_set_suspended(&pdev->dev);
 641         pm_runtime_enable(&pdev->dev);
 642 
 643         if (IS_ENABLED(CONFIG_THERMAL_OF)) {
 644                 info->tzd = thermal_zone_of_sensor_register(info->sensor_device,
 645                                                             0, info,
 646                                                             &sun4i_ts_tz_ops);
 647                 /*
 648                  * Do not fail driver probing when failing to register in
 649                  * thermal because no thermal DT node is found.
 650                  */
 651                 if (IS_ERR(info->tzd) && PTR_ERR(info->tzd) != -ENODEV) {
 652                         dev_err(&pdev->dev,
 653                                 "could not register thermal sensor: %ld\n",
 654                                 PTR_ERR(info->tzd));
 655                         return PTR_ERR(info->tzd);
 656                 }
 657         }
 658 
 659         ret = devm_iio_device_register(&pdev->dev, indio_dev);
 660         if (ret < 0) {
 661                 dev_err(&pdev->dev, "could not register the device\n");
 662                 goto err_map;
 663         }
 664 
 665         return 0;
 666 
 667 err_map:
 668         if (!info->no_irq && IS_ENABLED(CONFIG_THERMAL_OF))
 669                 iio_map_array_unregister(indio_dev);
 670 
 671         pm_runtime_put(&pdev->dev);
 672         pm_runtime_disable(&pdev->dev);
 673 
 674         return ret;
 675 }
 676 
 677 static int sun4i_gpadc_remove(struct platform_device *pdev)
 678 {
 679         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 680         struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
 681 
 682         pm_runtime_put(&pdev->dev);
 683         pm_runtime_disable(&pdev->dev);
 684 
 685         if (!IS_ENABLED(CONFIG_THERMAL_OF))
 686                 return 0;
 687 
 688         thermal_zone_of_sensor_unregister(info->sensor_device, info->tzd);
 689 
 690         if (!info->no_irq)
 691                 iio_map_array_unregister(indio_dev);
 692 
 693         return 0;
 694 }
 695 
 696 static const struct platform_device_id sun4i_gpadc_id[] = {
 697         { "sun4i-a10-gpadc-iio", (kernel_ulong_t)&sun4i_gpadc_data },
 698         { "sun5i-a13-gpadc-iio", (kernel_ulong_t)&sun5i_gpadc_data },
 699         { "sun6i-a31-gpadc-iio", (kernel_ulong_t)&sun6i_gpadc_data },
 700         { /* sentinel */ },
 701 };
 702 MODULE_DEVICE_TABLE(platform, sun4i_gpadc_id);
 703 
 704 static struct platform_driver sun4i_gpadc_driver = {
 705         .driver = {
 706                 .name = "sun4i-gpadc-iio",
 707                 .of_match_table = sun4i_gpadc_of_id,
 708                 .pm = &sun4i_gpadc_pm_ops,
 709         },
 710         .id_table = sun4i_gpadc_id,
 711         .probe = sun4i_gpadc_probe,
 712         .remove = sun4i_gpadc_remove,
 713 };
 714 MODULE_DEVICE_TABLE(of, sun4i_gpadc_of_id);
 715 
 716 module_platform_driver(sun4i_gpadc_driver);
 717 
 718 MODULE_DESCRIPTION("ADC driver for sunxi platforms");
 719 MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
 720 MODULE_LICENSE("GPL v2");