drivers/thermal/imx_thermal.c

   1 /*
   2  * Copyright 2013 Freescale Semiconductor, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  */
   9
  10 #include <linux/clk.h>
  11 #include <linux/cpu_cooling.h>
  12 #include <linux/delay.h>
  13 #include <linux/device.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <linux/kernel.h>
  18 #include <linux/mfd/syscon.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_device.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/regmap.h>
  24 #include <linux/slab.h>
  25 #include <linux/thermal.h>
  26 #include <linux/types.h>
  27
  28 #define REG_SET         0x4
  29 #define REG_CLR         0x8
  30 #define REG_TOG         0xc
  31
  32 #define MISC0                           0x0150
  33 #define MISC0_REFTOP_SELBIASOFF         (1 << 3)
  34 #define MISC1                           0x0160
  35 #define MISC1_IRQ_TEMPHIGH              (1 << 29)
  36 /* Below LOW and PANIC bits are only for TEMPMON_IMX6SX */
  37 #define MISC1_IRQ_TEMPLOW               (1 << 28)
  38 #define MISC1_IRQ_TEMPPANIC             (1 << 27)
  39
  40 #define TEMPSENSE0                      0x0180
  41 #define TEMPSENSE0_ALARM_VALUE_SHIFT    20
  42 #define TEMPSENSE0_ALARM_VALUE_MASK     (0xfff << TEMPSENSE0_ALARM_VALUE_SHIFT)
  43 #define TEMPSENSE0_TEMP_CNT_SHIFT       8
  44 #define TEMPSENSE0_TEMP_CNT_MASK        (0xfff << TEMPSENSE0_TEMP_CNT_SHIFT)
  45 #define TEMPSENSE0_FINISHED             (1 << 2)
  46 #define TEMPSENSE0_MEASURE_TEMP         (1 << 1)
  47 #define TEMPSENSE0_POWER_DOWN           (1 << 0)
  48
  49 #define TEMPSENSE1                      0x0190
  50 #define TEMPSENSE1_MEASURE_FREQ         0xffff
  51 /* Below TEMPSENSE2 is only for TEMPMON_IMX6SX */
  52 #define TEMPSENSE2                      0x0290
  53 #define TEMPSENSE2_LOW_VALUE_SHIFT      0
  54 #define TEMPSENSE2_LOW_VALUE_MASK       0xfff
  55 #define TEMPSENSE2_PANIC_VALUE_SHIFT    16
  56 #define TEMPSENSE2_PANIC_VALUE_MASK     0xfff0000
  57
  58 #define OCOTP_ANA1                      0x04e0
  59
  60 /* The driver supports 1 passive trip point and 1 critical trip point */
  61 enum imx_thermal_trip {
  62         IMX_TRIP_PASSIVE,
  63         IMX_TRIP_CRITICAL,
  64         IMX_TRIP_NUM,
  65 };
  66
  67 /*
  68  * It defines the temperature in millicelsius for passive trip point
  69  * that will trigger cooling action when crossed.
  70  */
  71 #define IMX_TEMP_PASSIVE                85000
  72
  73 #define IMX_POLLING_DELAY               2000 /* millisecond */
  74 #define IMX_PASSIVE_DELAY               1000
  75
  76 #define FACTOR0                         10000000
  77 #define FACTOR1                         15976
  78 #define FACTOR2                         4297157
  79
  80 #define TEMPMON_IMX6Q                   1
  81 #define TEMPMON_IMX6SX                  2
  82
  83 struct thermal_soc_data {
  84         u32 version;
  85 };
  86
  87 static struct thermal_soc_data thermal_imx6q_data = {
  88         .version = TEMPMON_IMX6Q,
  89 };
  90
  91 static struct thermal_soc_data thermal_imx6sx_data = {
  92         .version = TEMPMON_IMX6SX,
  93 };
  94
  95 struct imx_thermal_data {
  96         struct thermal_zone_device *tz;
  97         struct thermal_cooling_device *cdev;
  98         enum thermal_device_mode mode;
  99         struct regmap *tempmon;
 100         u32 c1, c2; /* See formula in imx_get_sensor_data() */
 101         int temp_passive;
 102         int temp_critical;
 103         int alarm_temp;
 104         int last_temp;
 105         bool irq_enabled;
 106         int irq;
 107         struct clk *thermal_clk;
 108         const struct thermal_soc_data *socdata;
 109 };
 110
 111 static void imx_set_panic_temp(struct imx_thermal_data *data,
 112                                int panic_temp)
 113 {
 114         struct regmap *map = data->tempmon;
 115         int critical_value;
 116
 117         critical_value = (data->c2 - panic_temp) / data->c1;
 118         regmap_write(map, TEMPSENSE2 + REG_CLR, TEMPSENSE2_PANIC_VALUE_MASK);
 119         regmap_write(map, TEMPSENSE2 + REG_SET, critical_value <<
 120                         TEMPSENSE2_PANIC_VALUE_SHIFT);
 121 }
 122
 123 static void imx_set_alarm_temp(struct imx_thermal_data *data,
 124                                int alarm_temp)
 125 {
 126         struct regmap *map = data->tempmon;
 127         int alarm_value;
 128
 129         data->alarm_temp = alarm_temp;
 130         alarm_value = (data->c2 - alarm_temp) / data->c1;
 131         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_ALARM_VALUE_MASK);
 132         regmap_write(map, TEMPSENSE0 + REG_SET, alarm_value <<
 133                         TEMPSENSE0_ALARM_VALUE_SHIFT);
 134 }
 135
 136 static int imx_get_temp(struct thermal_zone_device *tz, int *temp)
 137 {
 138         struct imx_thermal_data *data = tz->devdata;
 139         struct regmap *map = data->tempmon;
 140         unsigned int n_meas;
 141         bool wait;
 142         u32 val;
 143
 144         if (data->mode == THERMAL_DEVICE_ENABLED) {
 145                 /* Check if a measurement is currently in progress */
 146                 regmap_read(map, TEMPSENSE0, &val);
 147                 wait = !(val & TEMPSENSE0_FINISHED);
 148         } else {
 149                 /*
 150                  * Every time we measure the temperature, we will power on the
 151                  * temperature sensor, enable measurements, take a reading,
 152                  * disable measurements, power off the temperature sensor.
 153                  */
 154                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 155                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 156
 157                 wait = true;
 158         }
 159
 160         /*
 161          * According to the temp sensor designers, it may require up to ~17us
 162          * to complete a measurement.
 163          */
 164         if (wait)
 165                 usleep_range(20, 50);
 166
 167         regmap_read(map, TEMPSENSE0, &val);
 168
 169         if (data->mode != THERMAL_DEVICE_ENABLED) {
 170                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 171                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 172         }
 173
 174         if ((val & TEMPSENSE0_FINISHED) == 0) {
 175                 dev_dbg(&tz->device, "temp measurement never finished\n");
 176                 return -EAGAIN;
 177         }
 178
 179         n_meas = (val & TEMPSENSE0_TEMP_CNT_MASK) >> TEMPSENSE0_TEMP_CNT_SHIFT;
 180
 181         /* See imx_get_sensor_data() for formula derivation */
 182         *temp = data->c2 - n_meas * data->c1;
 183
 184         /* Update alarm value to next higher trip point for TEMPMON_IMX6Q */
 185         if (data->socdata->version == TEMPMON_IMX6Q) {
 186                 if (data->alarm_temp == data->temp_passive &&
 187                         *temp >= data->temp_passive)
 188                         imx_set_alarm_temp(data, data->temp_critical);
 189                 if (data->alarm_temp == data->temp_critical &&
 190                         *temp < data->temp_passive) {
 191                         imx_set_alarm_temp(data, data->temp_passive);
 192                         dev_dbg(&tz->device, "thermal alarm off: T < %d\n",
 193                                 data->alarm_temp / 1000);
 194                 }
 195         }
 196
 197         if (*temp != data->last_temp) {
 198                 dev_dbg(&tz->device, "millicelsius: %d\n", *temp);
 199                 data->last_temp = *temp;
 200         }
 201
 202         /* Reenable alarm IRQ if temperature below alarm temperature */
 203         if (!data->irq_enabled && *temp < data->alarm_temp) {
 204                 data->irq_enabled = true;
 205                 enable_irq(data->irq);
 206         }
 207
 208         return 0;
 209 }
 210
 211 static int imx_get_mode(struct thermal_zone_device *tz,
 212                         enum thermal_device_mode *mode)
 213 {
 214         struct imx_thermal_data *data = tz->devdata;
 215
 216         *mode = data->mode;
 217
 218         return 0;
 219 }
 220
 221 static int imx_set_mode(struct thermal_zone_device *tz,
 222                         enum thermal_device_mode mode)
 223 {
 224         struct imx_thermal_data *data = tz->devdata;
 225         struct regmap *map = data->tempmon;
 226
 227         if (mode == THERMAL_DEVICE_ENABLED) {
 228                 tz->polling_delay = IMX_POLLING_DELAY;
 229                 tz->passive_delay = IMX_PASSIVE_DELAY;
 230
 231                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 232                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 233
 234                 if (!data->irq_enabled) {
 235                         data->irq_enabled = true;
 236                         enable_irq(data->irq);
 237                 }
 238         } else {
 239                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 240                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 241
 242                 tz->polling_delay = 0;
 243                 tz->passive_delay = 0;
 244
 245                 if (data->irq_enabled) {
 246                         disable_irq(data->irq);
 247                         data->irq_enabled = false;
 248                 }
 249         }
 250
 251         data->mode = mode;
 252         thermal_zone_device_update(tz);
 253
 254         return 0;
 255 }
 256
 257 static int imx_get_trip_type(struct thermal_zone_device *tz, int trip,
 258                              enum thermal_trip_type *type)
 259 {
 260         *type = (trip == IMX_TRIP_PASSIVE) ? THERMAL_TRIP_PASSIVE :
 261                                              THERMAL_TRIP_CRITICAL;
 262         return 0;
 263 }
 264
 265 static int imx_get_crit_temp(struct thermal_zone_device *tz, int *temp)
 266 {
 267         struct imx_thermal_data *data = tz->devdata;
 268
 269         *temp = data->temp_critical;
 270         return 0;
 271 }
 272
 273 static int imx_get_trip_temp(struct thermal_zone_device *tz, int trip,
 274                              int *temp)
 275 {
 276         struct imx_thermal_data *data = tz->devdata;
 277
 278         *temp = (trip == IMX_TRIP_PASSIVE) ? data->temp_passive :
 279                                              data->temp_critical;
 280         return 0;
 281 }
 282
 283 static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip,
 284                              int temp)
 285 {
 286         struct imx_thermal_data *data = tz->devdata;
 287
 288         if (trip == IMX_TRIP_CRITICAL)
 289                 return -EPERM;
 290
 291         if (temp < 0 || temp > IMX_TEMP_PASSIVE)
 292                 return -EINVAL;
 293
 294         data->temp_passive = temp;
 295
 296         imx_set_alarm_temp(data, temp);
 297
 298         return 0;
 299 }
 300
 301 static int imx_bind(struct thermal_zone_device *tz,
 302                     struct thermal_cooling_device *cdev)
 303 {
 304         int ret;
 305
 306         ret = thermal_zone_bind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev,
 307                                                THERMAL_NO_LIMIT,
 308                                                THERMAL_NO_LIMIT,
 309                                                THERMAL_WEIGHT_DEFAULT);
 310         if (ret) {
 311                 dev_err(&tz->device,
 312                         "binding zone %s with cdev %s failed:%d\n",
 313                         tz->type, cdev->type, ret);
 314                 return ret;
 315         }
 316
 317         return 0;
 318 }
 319
 320 static int imx_unbind(struct thermal_zone_device *tz,
 321                       struct thermal_cooling_device *cdev)
 322 {
 323         int ret;
 324
 325         ret = thermal_zone_unbind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev);
 326         if (ret) {
 327                 dev_err(&tz->device,
 328                         "unbinding zone %s with cdev %s failed:%d\n",
 329                         tz->type, cdev->type, ret);
 330                 return ret;
 331         }
 332
 333         return 0;
 334 }
 335
 336 static struct thermal_zone_device_ops imx_tz_ops = {
 337         .bind = imx_bind,
 338         .unbind = imx_unbind,
 339         .get_temp = imx_get_temp,
 340         .get_mode = imx_get_mode,
 341         .set_mode = imx_set_mode,
 342         .get_trip_type = imx_get_trip_type,
 343         .get_trip_temp = imx_get_trip_temp,
 344         .get_crit_temp = imx_get_crit_temp,
 345         .set_trip_temp = imx_set_trip_temp,
 346 };
 347
 348 static int imx_get_sensor_data(struct platform_device *pdev)
 349 {
 350         struct imx_thermal_data *data = platform_get_drvdata(pdev);
 351         struct regmap *map;
 352         int t1, n1;
 353         int ret;
 354         u32 val;
 355         u64 temp64;
 356
 357         map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
 358                                               "fsl,tempmon-data");
 359         if (IS_ERR(map)) {
 360                 ret = PTR_ERR(map);
 361                 dev_err(&pdev->dev, "failed to get sensor regmap: %d\n", ret);
 362                 return ret;
 363         }
 364
 365         ret = regmap_read(map, OCOTP_ANA1, &val);
 366         if (ret) {
 367                 dev_err(&pdev->dev, "failed to read sensor data: %d\n", ret);
 368                 return ret;
 369         }
 370
 371         if (val == 0 || val == ~0) {
 372                 dev_err(&pdev->dev, "invalid sensor calibration data\n");
 373                 return -EINVAL;
 374         }
 375
 376         /*
 377          * Sensor data layout:
 378          *   [31:20] - sensor value @ 25C
 379          * Use universal formula now and only need sensor value @ 25C
 380          * slope = 0.4297157 - (0.0015976 * 25C fuse)
 381          */
 382         n1 = val >> 20;
 383         t1 = 25; /* t1 always 25C */
 384
 385         /*
 386          * Derived from linear interpolation:
 387          * slope = 0.4297157 - (0.0015976 * 25C fuse)
 388          * slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0
 389          * (Nmeas - n1) / (Tmeas - t1) = slope
 390          * We want to reduce this down to the minimum computation necessary
 391          * for each temperature read.  Also, we want Tmeas in millicelsius
 392          * and we don't want to lose precision from integer division. So...
 393          * Tmeas = (Nmeas - n1) / slope + t1
 394          * milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1
 395          * milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1
 396          * Let constant c1 = (-1000 / slope)
 397          * milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1
 398          * Let constant c2 = n1 *c1 + 1000 * t1
 399          * milli_Tmeas = c2 - Nmeas * c1
 400          */
 401         temp64 = FACTOR0;
 402         temp64 *= 1000;
 403         do_div(temp64, FACTOR1 * n1 - FACTOR2);
 404         data->c1 = temp64;
 405         data->c2 = n1 * data->c1 + 1000 * t1;
 406
 407         /*
 408          * Set the default passive cooling trip point,
 409          * can be changed from userspace.
 410          */
 411         data->temp_passive = IMX_TEMP_PASSIVE;
 412
 413         /*
 414          * The maximum die temperature set to 20 C higher than
 415          * IMX_TEMP_PASSIVE.
 416          */
 417         data->temp_critical = 1000 * 20 + data->temp_passive;
 418
 419         return 0;
 420 }
 421
 422 static irqreturn_t imx_thermal_alarm_irq(int irq, void *dev)
 423 {
 424         struct imx_thermal_data *data = dev;
 425
 426         disable_irq_nosync(irq);
 427         data->irq_enabled = false;
 428
 429         return IRQ_WAKE_THREAD;
 430 }
 431
 432 static irqreturn_t imx_thermal_alarm_irq_thread(int irq, void *dev)
 433 {
 434         struct imx_thermal_data *data = dev;
 435
 436         dev_dbg(&data->tz->device, "THERMAL ALARM: T > %d\n",
 437                 data->alarm_temp / 1000);
 438
 439         thermal_zone_device_update(data->tz);
 440
 441         return IRQ_HANDLED;
 442 }
 443
 444 static const struct of_device_id of_imx_thermal_match[] = {
 445         { .compatible = "fsl,imx6q-tempmon", .data = &thermal_imx6q_data, },
 446         { .compatible = "fsl,imx6sx-tempmon", .data = &thermal_imx6sx_data, },
 447         { /* end */ }
 448 };
 449 MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
 450
 451 static int imx_thermal_probe(struct platform_device *pdev)
 452 {
 453         const struct of_device_id *of_id =
 454                 of_match_device(of_imx_thermal_match, &pdev->dev);
 455         struct imx_thermal_data *data;
 456         struct regmap *map;
 457         int measure_freq;
 458         int ret;
 459
 460         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 461         if (!data)
 462                 return -ENOMEM;
 463
 464         map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon");
 465         if (IS_ERR(map)) {
 466                 ret = PTR_ERR(map);
 467                 dev_err(&pdev->dev, "failed to get tempmon regmap: %d\n", ret);
 468                 return ret;
 469         }
 470         data->tempmon = map;
 471
 472         data->socdata = of_id->data;
 473
 474         /* make sure the IRQ flag is clear before enabling irq on i.MX6SX */
 475         if (data->socdata->version == TEMPMON_IMX6SX) {
 476                 regmap_write(map, MISC1 + REG_CLR, MISC1_IRQ_TEMPHIGH |
 477                         MISC1_IRQ_TEMPLOW | MISC1_IRQ_TEMPPANIC);
 478                 /*
 479                  * reset value of LOW ALARM is incorrect, set it to lowest
 480                  * value to avoid false trigger of low alarm.
 481                  */
 482                 regmap_write(map, TEMPSENSE2 + REG_SET,
 483                         TEMPSENSE2_LOW_VALUE_MASK);
 484         }
 485
 486         data->irq = platform_get_irq(pdev, 0);
 487         if (data->irq < 0)
 488                 return data->irq;
 489
 490         platform_set_drvdata(pdev, data);
 491
 492         ret = imx_get_sensor_data(pdev);
 493         if (ret) {
 494                 dev_err(&pdev->dev, "failed to get sensor data\n");
 495                 return ret;
 496         }
 497
 498         /* Make sure sensor is in known good state for measurements */
 499         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 500         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 501         regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
 502         regmap_write(map, MISC0 + REG_SET, MISC0_REFTOP_SELBIASOFF);
 503         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 504
 505         data->cdev = cpufreq_cooling_register(cpu_present_mask);
 506         if (IS_ERR(data->cdev)) {
 507                 ret = PTR_ERR(data->cdev);
 508                 if (ret != -EPROBE_DEFER)
 509                         dev_err(&pdev->dev,
 510                                 "failed to register cpufreq cooling device: %d\n",
 511                                 ret);
 512                 return ret;
 513         }
 514
 515         data->thermal_clk = devm_clk_get(&pdev->dev, NULL);
 516         if (IS_ERR(data->thermal_clk)) {
 517                 ret = PTR_ERR(data->thermal_clk);
 518                 if (ret != -EPROBE_DEFER)
 519                         dev_err(&pdev->dev,
 520                                 "failed to get thermal clk: %d\n", ret);
 521                 cpufreq_cooling_unregister(data->cdev);
 522                 return ret;
 523         }
 524
 525         /*
 526          * Thermal sensor needs clk on to get correct value, normally
 527          * we should enable its clk before taking measurement and disable
 528          * clk after measurement is done, but if alarm function is enabled,
 529          * hardware will auto measure the temperature periodically, so we
 530          * need to keep the clk always on for alarm function.
 531          */
 532         ret = clk_prepare_enable(data->thermal_clk);
 533         if (ret) {
 534                 dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
 535                 cpufreq_cooling_unregister(data->cdev);
 536                 return ret;
 537         }
 538
 539         data->tz = thermal_zone_device_register("imx_thermal_zone",
 540                                                 IMX_TRIP_NUM,
 541                                                 BIT(IMX_TRIP_PASSIVE), data,
 542                                                 &imx_tz_ops, NULL,
 543                                                 IMX_PASSIVE_DELAY,
 544                                                 IMX_POLLING_DELAY);
 545         if (IS_ERR(data->tz)) {
 546                 ret = PTR_ERR(data->tz);
 547                 dev_err(&pdev->dev,
 548                         "failed to register thermal zone device %d\n", ret);
 549                 clk_disable_unprepare(data->thermal_clk);
 550                 cpufreq_cooling_unregister(data->cdev);
 551                 return ret;
 552         }
 553
 554         /* Enable measurements at ~ 10 Hz */
 555         regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
 556         measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */
 557         regmap_write(map, TEMPSENSE1 + REG_SET, measure_freq);
 558         imx_set_alarm_temp(data, data->temp_passive);
 559
 560         if (data->socdata->version == TEMPMON_IMX6SX)
 561                 imx_set_panic_temp(data, data->temp_critical);
 562
 563         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 564         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 565
 566         ret = devm_request_threaded_irq(&pdev->dev, data->irq,
 567                         imx_thermal_alarm_irq, imx_thermal_alarm_irq_thread,
 568                         0, "imx_thermal", data);
 569         if (ret < 0) {
 570                 dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
 571                 clk_disable_unprepare(data->thermal_clk);
 572                 thermal_zone_device_unregister(data->tz);
 573                 cpufreq_cooling_unregister(data->cdev);
 574                 return ret;
 575         }
 576
 577         data->irq_enabled = true;
 578         data->mode = THERMAL_DEVICE_ENABLED;
 579
 580         return 0;
 581 }
 582
 583 static int imx_thermal_remove(struct platform_device *pdev)
 584 {
 585         struct imx_thermal_data *data = platform_get_drvdata(pdev);
 586         struct regmap *map = data->tempmon;
 587
 588         /* Disable measurements */
 589         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 590         if (!IS_ERR(data->thermal_clk))
 591                 clk_disable_unprepare(data->thermal_clk);
 592
 593         thermal_zone_device_unregister(data->tz);
 594         cpufreq_cooling_unregister(data->cdev);
 595
 596         return 0;
 597 }
 598
 599 #ifdef CONFIG_PM_SLEEP
 600 static int imx_thermal_suspend(struct device *dev)
 601 {
 602         struct imx_thermal_data *data = dev_get_drvdata(dev);
 603         struct regmap *map = data->tempmon;
 604
 605         /*
 606          * Need to disable thermal sensor, otherwise, when thermal core
 607          * try to get temperature before thermal sensor resume, a wrong
 608          * temperature will be read as the thermal sensor is powered
 609          * down.
 610          */
 611         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 612         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 613         data->mode = THERMAL_DEVICE_DISABLED;
 614         clk_disable_unprepare(data->thermal_clk);
 615
 616         return 0;
 617 }
 618
 619 static int imx_thermal_resume(struct device *dev)
 620 {
 621         struct imx_thermal_data *data = dev_get_drvdata(dev);
 622         struct regmap *map = data->tempmon;
 623
 624         clk_prepare_enable(data->thermal_clk);
 625         /* Enabled thermal sensor after resume */
 626         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 627         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 628         data->mode = THERMAL_DEVICE_ENABLED;
 629
 630         return 0;
 631 }
 632 #endif
 633
 634 static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
 635                          imx_thermal_suspend, imx_thermal_resume);
 636
 637 static struct platform_driver imx_thermal = {
 638         .driver = {
 639                 .name   = "imx_thermal",
 640                 .pm     = &imx_thermal_pm_ops,
 641                 .of_match_table = of_imx_thermal_match,
 642         },
 643         .probe          = imx_thermal_probe,
 644         .remove         = imx_thermal_remove,
 645 };
 646 module_platform_driver(imx_thermal);
 647
 648 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
 649 MODULE_DESCRIPTION("Thermal driver for Freescale i.MX SoCs");
 650 MODULE_LICENSE("GPL v2");
 651 MODULE_ALIAS("platform:imx-thermal");