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