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/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
  35 #define TEMPSENSE0                      0x0180
  36 #define TEMPSENSE0_ALARM_VALUE_SHIFT    20
  37 #define TEMPSENSE0_ALARM_VALUE_MASK     (0xfff << TEMPSENSE0_ALARM_VALUE_SHIFT)
  38 #define TEMPSENSE0_TEMP_CNT_SHIFT       8
  39 #define TEMPSENSE0_TEMP_CNT_MASK        (0xfff << TEMPSENSE0_TEMP_CNT_SHIFT)
  40 #define TEMPSENSE0_FINISHED             (1 << 2)
  41 #define TEMPSENSE0_MEASURE_TEMP         (1 << 1)
  42 #define TEMPSENSE0_POWER_DOWN           (1 << 0)
  43
  44 #define TEMPSENSE1                      0x0190
  45 #define TEMPSENSE1_MEASURE_FREQ         0xffff
  46
  47 #define OCOTP_ANA1                      0x04e0
  48
  49 /* The driver supports 1 passive trip point and 1 critical trip point */
  50 enum imx_thermal_trip {
  51         IMX_TRIP_PASSIVE,
  52         IMX_TRIP_CRITICAL,
  53         IMX_TRIP_NUM,
  54 };
  55
  56 /*
  57  * It defines the temperature in millicelsius for passive trip point
  58  * that will trigger cooling action when crossed.
  59  */
  60 #define IMX_TEMP_PASSIVE                85000
  61
  62 #define IMX_POLLING_DELAY               2000 /* millisecond */
  63 #define IMX_PASSIVE_DELAY               1000
  64
  65 struct imx_thermal_data {
  66         struct thermal_zone_device *tz;
  67         struct thermal_cooling_device *cdev;
  68         enum thermal_device_mode mode;
  69         struct regmap *tempmon;
  70         int c1, c2; /* See formula in imx_get_sensor_data() */
  71         unsigned long temp_passive;
  72         unsigned long temp_critical;
  73         unsigned long alarm_temp;
  74         unsigned long last_temp;
  75         bool irq_enabled;
  76         int irq;
  77         struct clk *thermal_clk;
  78 };
  79
  80 static void imx_set_alarm_temp(struct imx_thermal_data *data,
  81                                signed long alarm_temp)
  82 {
  83         struct regmap *map = data->tempmon;
  84         int alarm_value;
  85
  86         data->alarm_temp = alarm_temp;
  87         alarm_value = (alarm_temp - data->c2) / data->c1;
  88         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_ALARM_VALUE_MASK);
  89         regmap_write(map, TEMPSENSE0 + REG_SET, alarm_value <<
  90                         TEMPSENSE0_ALARM_VALUE_SHIFT);
  91 }
  92
  93 static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
  94 {
  95         struct imx_thermal_data *data = tz->devdata;
  96         struct regmap *map = data->tempmon;
  97         unsigned int n_meas;
  98         bool wait;
  99         u32 val;
 100
 101         if (data->mode == THERMAL_DEVICE_ENABLED) {
 102                 /* Check if a measurement is currently in progress */
 103                 regmap_read(map, TEMPSENSE0, &val);
 104                 wait = !(val & TEMPSENSE0_FINISHED);
 105         } else {
 106                 /*
 107                  * Every time we measure the temperature, we will power on the
 108                  * temperature sensor, enable measurements, take a reading,
 109                  * disable measurements, power off the temperature sensor.
 110                  */
 111                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 112                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 113
 114                 wait = true;
 115         }
 116
 117         /*
 118          * According to the temp sensor designers, it may require up to ~17us
 119          * to complete a measurement.
 120          */
 121         if (wait)
 122                 usleep_range(20, 50);
 123
 124         regmap_read(map, TEMPSENSE0, &val);
 125
 126         if (data->mode != THERMAL_DEVICE_ENABLED) {
 127                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 128                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 129         }
 130
 131         if ((val & TEMPSENSE0_FINISHED) == 0) {
 132                 dev_dbg(&tz->device, "temp measurement never finished\n");
 133                 return -EAGAIN;
 134         }
 135
 136         n_meas = (val & TEMPSENSE0_TEMP_CNT_MASK) >> TEMPSENSE0_TEMP_CNT_SHIFT;
 137
 138         /* See imx_get_sensor_data() for formula derivation */
 139         *temp = data->c2 + data->c1 * n_meas;
 140
 141         /* Update alarm value to next higher trip point */
 142         if (data->alarm_temp == data->temp_passive && *temp >= data->temp_passive)
 143                 imx_set_alarm_temp(data, data->temp_critical);
 144         if (data->alarm_temp == data->temp_critical && *temp < data->temp_passive) {
 145                 imx_set_alarm_temp(data, data->temp_passive);
 146                 dev_dbg(&tz->device, "thermal alarm off: T < %lu\n",
 147                         data->alarm_temp / 1000);
 148         }
 149
 150         if (*temp != data->last_temp) {
 151                 dev_dbg(&tz->device, "millicelsius: %ld\n", *temp);
 152                 data->last_temp = *temp;
 153         }
 154
 155         /* Reenable alarm IRQ if temperature below alarm temperature */
 156         if (!data->irq_enabled && *temp < data->alarm_temp) {
 157                 data->irq_enabled = true;
 158                 enable_irq(data->irq);
 159         }
 160
 161         return 0;
 162 }
 163
 164 static int imx_get_mode(struct thermal_zone_device *tz,
 165                         enum thermal_device_mode *mode)
 166 {
 167         struct imx_thermal_data *data = tz->devdata;
 168
 169         *mode = data->mode;
 170
 171         return 0;
 172 }
 173
 174 static int imx_set_mode(struct thermal_zone_device *tz,
 175                         enum thermal_device_mode mode)
 176 {
 177         struct imx_thermal_data *data = tz->devdata;
 178         struct regmap *map = data->tempmon;
 179
 180         if (mode == THERMAL_DEVICE_ENABLED) {
 181                 tz->polling_delay = IMX_POLLING_DELAY;
 182                 tz->passive_delay = IMX_PASSIVE_DELAY;
 183
 184                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 185                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 186
 187                 if (!data->irq_enabled) {
 188                         data->irq_enabled = true;
 189                         enable_irq(data->irq);
 190                 }
 191         } else {
 192                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 193                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 194
 195                 tz->polling_delay = 0;
 196                 tz->passive_delay = 0;
 197
 198                 if (data->irq_enabled) {
 199                         disable_irq(data->irq);
 200                         data->irq_enabled = false;
 201                 }
 202         }
 203
 204         data->mode = mode;
 205         thermal_zone_device_update(tz);
 206
 207         return 0;
 208 }
 209
 210 static int imx_get_trip_type(struct thermal_zone_device *tz, int trip,
 211                              enum thermal_trip_type *type)
 212 {
 213         *type = (trip == IMX_TRIP_PASSIVE) ? THERMAL_TRIP_PASSIVE :
 214                                              THERMAL_TRIP_CRITICAL;
 215         return 0;
 216 }
 217
 218 static int imx_get_crit_temp(struct thermal_zone_device *tz,
 219                              unsigned long *temp)
 220 {
 221         struct imx_thermal_data *data = tz->devdata;
 222
 223         *temp = data->temp_critical;
 224         return 0;
 225 }
 226
 227 static int imx_get_trip_temp(struct thermal_zone_device *tz, int trip,
 228                              unsigned long *temp)
 229 {
 230         struct imx_thermal_data *data = tz->devdata;
 231
 232         *temp = (trip == IMX_TRIP_PASSIVE) ? data->temp_passive :
 233                                              data->temp_critical;
 234         return 0;
 235 }
 236
 237 static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip,
 238                              unsigned long temp)
 239 {
 240         struct imx_thermal_data *data = tz->devdata;
 241
 242         if (trip == IMX_TRIP_CRITICAL)
 243                 return -EPERM;
 244
 245         if (temp > IMX_TEMP_PASSIVE)
 246                 return -EINVAL;
 247
 248         data->temp_passive = temp;
 249
 250         imx_set_alarm_temp(data, temp);
 251
 252         return 0;
 253 }
 254
 255 static int imx_bind(struct thermal_zone_device *tz,
 256                     struct thermal_cooling_device *cdev)
 257 {
 258         int ret;
 259
 260         ret = thermal_zone_bind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev,
 261                                                THERMAL_NO_LIMIT,
 262                                                THERMAL_NO_LIMIT);
 263         if (ret) {
 264                 dev_err(&tz->device,
 265                         "binding zone %s with cdev %s failed:%d\n",
 266                         tz->type, cdev->type, ret);
 267                 return ret;
 268         }
 269
 270         return 0;
 271 }
 272
 273 static int imx_unbind(struct thermal_zone_device *tz,
 274                       struct thermal_cooling_device *cdev)
 275 {
 276         int ret;
 277
 278         ret = thermal_zone_unbind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev);
 279         if (ret) {
 280                 dev_err(&tz->device,
 281                         "unbinding zone %s with cdev %s failed:%d\n",
 282                         tz->type, cdev->type, ret);
 283                 return ret;
 284         }
 285
 286         return 0;
 287 }
 288
 289 static struct thermal_zone_device_ops imx_tz_ops = {
 290         .bind = imx_bind,
 291         .unbind = imx_unbind,
 292         .get_temp = imx_get_temp,
 293         .get_mode = imx_get_mode,
 294         .set_mode = imx_set_mode,
 295         .get_trip_type = imx_get_trip_type,
 296         .get_trip_temp = imx_get_trip_temp,
 297         .get_crit_temp = imx_get_crit_temp,
 298         .set_trip_temp = imx_set_trip_temp,
 299 };
 300
 301 static int imx_get_sensor_data(struct platform_device *pdev)
 302 {
 303         struct imx_thermal_data *data = platform_get_drvdata(pdev);
 304         struct regmap *map;
 305         int t1, t2, n1, n2;
 306         int ret;
 307         u32 val;
 308
 309         map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
 310                                               "fsl,tempmon-data");
 311         if (IS_ERR(map)) {
 312                 ret = PTR_ERR(map);
 313                 dev_err(&pdev->dev, "failed to get sensor regmap: %d\n", ret);
 314                 return ret;
 315         }
 316
 317         ret = regmap_read(map, OCOTP_ANA1, &val);
 318         if (ret) {
 319                 dev_err(&pdev->dev, "failed to read sensor data: %d\n", ret);
 320                 return ret;
 321         }
 322
 323         if (val == 0 || val == ~0) {
 324                 dev_err(&pdev->dev, "invalid sensor calibration data\n");
 325                 return -EINVAL;
 326         }
 327
 328         /*
 329          * Sensor data layout:
 330          *   [31:20] - sensor value @ 25C
 331          *    [19:8] - sensor value of hot
 332          *     [7:0] - hot temperature value
 333          */
 334         n1 = val >> 20;
 335         n2 = (val & 0xfff00) >> 8;
 336         t2 = val & 0xff;
 337         t1 = 25; /* t1 always 25C */
 338
 339         /*
 340          * Derived from linear interpolation,
 341          * Tmeas = T2 + (Nmeas - N2) * (T1 - T2) / (N1 - N2)
 342          * We want to reduce this down to the minimum computation necessary
 343          * for each temperature read.  Also, we want Tmeas in millicelsius
 344          * and we don't want to lose precision from integer division. So...
 345          * milli_Tmeas = 1000 * T2 + 1000 * (Nmeas - N2) * (T1 - T2) / (N1 - N2)
 346          * Let constant c1 = 1000 * (T1 - T2) / (N1 - N2)
 347          * milli_Tmeas = (1000 * T2) + c1 * (Nmeas - N2)
 348          * milli_Tmeas = (1000 * T2) + (c1 * Nmeas) - (c1 * N2)
 349          * Let constant c2 = (1000 * T2) - (c1 * N2)
 350          * milli_Tmeas = c2 + (c1 * Nmeas)
 351          */
 352         data->c1 = 1000 * (t1 - t2) / (n1 - n2);
 353         data->c2 = 1000 * t2 - data->c1 * n2;
 354
 355         /*
 356          * Set the default passive cooling trip point to 20 °C below the
 357          * maximum die temperature. Can be changed from userspace.
 358          */
 359         data->temp_passive = 1000 * (t2 - 20);
 360
 361         /*
 362          * The maximum die temperature is t2, let's give 5 °C cushion
 363          * for noise and possible temperature rise between measurements.
 364          */
 365         data->temp_critical = 1000 * (t2 - 5);
 366
 367         return 0;
 368 }
 369
 370 static irqreturn_t imx_thermal_alarm_irq(int irq, void *dev)
 371 {
 372         struct imx_thermal_data *data = dev;
 373
 374         disable_irq_nosync(irq);
 375         data->irq_enabled = false;
 376
 377         return IRQ_WAKE_THREAD;
 378 }
 379
 380 static irqreturn_t imx_thermal_alarm_irq_thread(int irq, void *dev)
 381 {
 382         struct imx_thermal_data *data = dev;
 383
 384         dev_dbg(&data->tz->device, "THERMAL ALARM: T > %lu\n",
 385                 data->alarm_temp / 1000);
 386
 387         thermal_zone_device_update(data->tz);
 388
 389         return IRQ_HANDLED;
 390 }
 391
 392 static int imx_thermal_probe(struct platform_device *pdev)
 393 {
 394         struct imx_thermal_data *data;
 395         struct cpumask clip_cpus;
 396         struct regmap *map;
 397         int measure_freq;
 398         int ret;
 399
 400         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 401         if (!data)
 402                 return -ENOMEM;
 403
 404         map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon");
 405         if (IS_ERR(map)) {
 406                 ret = PTR_ERR(map);
 407                 dev_err(&pdev->dev, "failed to get tempmon regmap: %d\n", ret);
 408                 return ret;
 409         }
 410         data->tempmon = map;
 411
 412         data->irq = platform_get_irq(pdev, 0);
 413         if (data->irq < 0)
 414                 return data->irq;
 415
 416         ret = devm_request_threaded_irq(&pdev->dev, data->irq,
 417                         imx_thermal_alarm_irq, imx_thermal_alarm_irq_thread,
 418                         0, "imx_thermal", data);
 419         if (ret < 0) {
 420                 dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
 421                 return ret;
 422         }
 423
 424         platform_set_drvdata(pdev, data);
 425
 426         ret = imx_get_sensor_data(pdev);
 427         if (ret) {
 428                 dev_err(&pdev->dev, "failed to get sensor data\n");
 429                 return ret;
 430         }
 431
 432         /* Make sure sensor is in known good state for measurements */
 433         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 434         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 435         regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
 436         regmap_write(map, MISC0 + REG_SET, MISC0_REFTOP_SELBIASOFF);
 437         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 438
 439         cpumask_set_cpu(0, &clip_cpus);
 440         data->cdev = cpufreq_cooling_register(&clip_cpus);
 441         if (IS_ERR(data->cdev)) {
 442                 ret = PTR_ERR(data->cdev);
 443                 dev_err(&pdev->dev,
 444                         "failed to register cpufreq cooling device: %d\n", ret);
 445                 return ret;
 446         }
 447
 448         data->tz = thermal_zone_device_register("imx_thermal_zone",
 449                                                 IMX_TRIP_NUM,
 450                                                 BIT(IMX_TRIP_PASSIVE), data,
 451                                                 &imx_tz_ops, NULL,
 452                                                 IMX_PASSIVE_DELAY,
 453                                                 IMX_POLLING_DELAY);
 454         if (IS_ERR(data->tz)) {
 455                 ret = PTR_ERR(data->tz);
 456                 dev_err(&pdev->dev,
 457                         "failed to register thermal zone device %d\n", ret);
 458                 cpufreq_cooling_unregister(data->cdev);
 459                 return ret;
 460         }
 461
 462         data->thermal_clk = devm_clk_get(&pdev->dev, NULL);
 463         if (IS_ERR(data->thermal_clk)) {
 464                 dev_warn(&pdev->dev, "failed to get thermal clk!\n");
 465         } else {
 466                 /*
 467                  * Thermal sensor needs clk on to get correct value, normally
 468                  * we should enable its clk before taking measurement and disable
 469                  * clk after measurement is done, but if alarm function is enabled,
 470                  * hardware will auto measure the temperature periodically, so we
 471                  * need to keep the clk always on for alarm function.
 472                  */
 473                 ret = clk_prepare_enable(data->thermal_clk);
 474                 if (ret)
 475                         dev_warn(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
 476         }
 477
 478         /* Enable measurements at ~ 10 Hz */
 479         regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
 480         measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */
 481         regmap_write(map, TEMPSENSE1 + REG_SET, measure_freq);
 482         imx_set_alarm_temp(data, data->temp_passive);
 483         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 484         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 485
 486         data->irq_enabled = true;
 487         data->mode = THERMAL_DEVICE_ENABLED;
 488
 489         return 0;
 490 }
 491
 492 static int imx_thermal_remove(struct platform_device *pdev)
 493 {
 494         struct imx_thermal_data *data = platform_get_drvdata(pdev);
 495         struct regmap *map = data->tempmon;
 496
 497         /* Disable measurements */
 498         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 499         if (!IS_ERR(data->thermal_clk))
 500                 clk_disable_unprepare(data->thermal_clk);
 501
 502         thermal_zone_device_unregister(data->tz);
 503         cpufreq_cooling_unregister(data->cdev);
 504
 505         return 0;
 506 }
 507
 508 #ifdef CONFIG_PM_SLEEP
 509 static int imx_thermal_suspend(struct device *dev)
 510 {
 511         struct imx_thermal_data *data = dev_get_drvdata(dev);
 512         struct regmap *map = data->tempmon;
 513
 514         /*
 515          * Need to disable thermal sensor, otherwise, when thermal core
 516          * try to get temperature before thermal sensor resume, a wrong
 517          * temperature will be read as the thermal sensor is powered
 518          * down.
 519          */
 520         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 521         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 522         data->mode = THERMAL_DEVICE_DISABLED;
 523
 524         return 0;
 525 }
 526
 527 static int imx_thermal_resume(struct device *dev)
 528 {
 529         struct imx_thermal_data *data = dev_get_drvdata(dev);
 530         struct regmap *map = data->tempmon;
 531
 532         /* Enabled thermal sensor after resume */
 533         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 534         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 535         data->mode = THERMAL_DEVICE_ENABLED;
 536
 537         return 0;
 538 }
 539 #endif
 540
 541 static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
 542                          imx_thermal_suspend, imx_thermal_resume);
 543
 544 static const struct of_device_id of_imx_thermal_match[] = {
 545         { .compatible = "fsl,imx6q-tempmon", },
 546         { /* end */ }
 547 };
 548 MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
 549
 550 static struct platform_driver imx_thermal = {
 551         .driver = {
 552                 .name   = "imx_thermal",
 553                 .owner  = THIS_MODULE,
 554                 .pm     = &imx_thermal_pm_ops,
 555                 .of_match_table = of_imx_thermal_match,
 556         },
 557         .probe          = imx_thermal_probe,
 558         .remove         = imx_thermal_remove,
 559 };
 560 module_platform_driver(imx_thermal);
 561
 562 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
 563 MODULE_DESCRIPTION("Thermal driver for Freescale i.MX SoCs");
 564 MODULE_LICENSE("GPL v2");
 565 MODULE_ALIAS("platform:imx-thermal");