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 #define FACTOR0                         10000000
  66 #define FACTOR1                         15976
  67 #define FACTOR2                         4297157
  68
  69 struct imx_thermal_data {
  70         struct thermal_zone_device *tz;
  71         struct thermal_cooling_device *cdev;
  72         enum thermal_device_mode mode;
  73         struct regmap *tempmon;
  74         u32 c1, c2; /* See formula in imx_get_sensor_data() */
  75         unsigned long temp_passive;
  76         unsigned long temp_critical;
  77         unsigned long alarm_temp;
  78         unsigned long last_temp;
  79         bool irq_enabled;
  80         int irq;
  81         struct clk *thermal_clk;
  82 };
  83
  84 static void imx_set_alarm_temp(struct imx_thermal_data *data,
  85                                signed long alarm_temp)
  86 {
  87         struct regmap *map = data->tempmon;
  88         int alarm_value;
  89
  90         data->alarm_temp = alarm_temp;
  91         alarm_value = (data->c2 - alarm_temp) / data->c1;
  92         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_ALARM_VALUE_MASK);
  93         regmap_write(map, TEMPSENSE0 + REG_SET, alarm_value <<
  94                         TEMPSENSE0_ALARM_VALUE_SHIFT);
  95 }
  96
  97 static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
  98 {
  99         struct imx_thermal_data *data = tz->devdata;
 100         struct regmap *map = data->tempmon;
 101         unsigned int n_meas;
 102         bool wait;
 103         u32 val;
 104
 105         if (data->mode == THERMAL_DEVICE_ENABLED) {
 106                 /* Check if a measurement is currently in progress */
 107                 regmap_read(map, TEMPSENSE0, &val);
 108                 wait = !(val & TEMPSENSE0_FINISHED);
 109         } else {
 110                 /*
 111                  * Every time we measure the temperature, we will power on the
 112                  * temperature sensor, enable measurements, take a reading,
 113                  * disable measurements, power off the temperature sensor.
 114                  */
 115                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 116                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 117
 118                 wait = true;
 119         }
 120
 121         /*
 122          * According to the temp sensor designers, it may require up to ~17us
 123          * to complete a measurement.
 124          */
 125         if (wait)
 126                 usleep_range(20, 50);
 127
 128         regmap_read(map, TEMPSENSE0, &val);
 129
 130         if (data->mode != THERMAL_DEVICE_ENABLED) {
 131                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 132                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 133         }
 134
 135         if ((val & TEMPSENSE0_FINISHED) == 0) {
 136                 dev_dbg(&tz->device, "temp measurement never finished\n");
 137                 return -EAGAIN;
 138         }
 139
 140         n_meas = (val & TEMPSENSE0_TEMP_CNT_MASK) >> TEMPSENSE0_TEMP_CNT_SHIFT;
 141
 142         /* See imx_get_sensor_data() for formula derivation */
 143         *temp = data->c2 - n_meas * data->c1;
 144
 145         /* Update alarm value to next higher trip point */
 146         if (data->alarm_temp == data->temp_passive && *temp >= data->temp_passive)
 147                 imx_set_alarm_temp(data, data->temp_critical);
 148         if (data->alarm_temp == data->temp_critical && *temp < data->temp_passive) {
 149                 imx_set_alarm_temp(data, data->temp_passive);
 150                 dev_dbg(&tz->device, "thermal alarm off: T < %lu\n",
 151                         data->alarm_temp / 1000);
 152         }
 153
 154         if (*temp != data->last_temp) {
 155                 dev_dbg(&tz->device, "millicelsius: %ld\n", *temp);
 156                 data->last_temp = *temp;
 157         }
 158
 159         /* Reenable alarm IRQ if temperature below alarm temperature */
 160         if (!data->irq_enabled && *temp < data->alarm_temp) {
 161                 data->irq_enabled = true;
 162                 enable_irq(data->irq);
 163         }
 164
 165         return 0;
 166 }
 167
 168 static int imx_get_mode(struct thermal_zone_device *tz,
 169                         enum thermal_device_mode *mode)
 170 {
 171         struct imx_thermal_data *data = tz->devdata;
 172
 173         *mode = data->mode;
 174
 175         return 0;
 176 }
 177
 178 static int imx_set_mode(struct thermal_zone_device *tz,
 179                         enum thermal_device_mode mode)
 180 {
 181         struct imx_thermal_data *data = tz->devdata;
 182         struct regmap *map = data->tempmon;
 183
 184         if (mode == THERMAL_DEVICE_ENABLED) {
 185                 tz->polling_delay = IMX_POLLING_DELAY;
 186                 tz->passive_delay = IMX_PASSIVE_DELAY;
 187
 188                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 189                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 190
 191                 if (!data->irq_enabled) {
 192                         data->irq_enabled = true;
 193                         enable_irq(data->irq);
 194                 }
 195         } else {
 196                 regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 197                 regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 198
 199                 tz->polling_delay = 0;
 200                 tz->passive_delay = 0;
 201
 202                 if (data->irq_enabled) {
 203                         disable_irq(data->irq);
 204                         data->irq_enabled = false;
 205                 }
 206         }
 207
 208         data->mode = mode;
 209         thermal_zone_device_update(tz);
 210
 211         return 0;
 212 }
 213
 214 static int imx_get_trip_type(struct thermal_zone_device *tz, int trip,
 215                              enum thermal_trip_type *type)
 216 {
 217         *type = (trip == IMX_TRIP_PASSIVE) ? THERMAL_TRIP_PASSIVE :
 218                                              THERMAL_TRIP_CRITICAL;
 219         return 0;
 220 }
 221
 222 static int imx_get_crit_temp(struct thermal_zone_device *tz,
 223                              unsigned long *temp)
 224 {
 225         struct imx_thermal_data *data = tz->devdata;
 226
 227         *temp = data->temp_critical;
 228         return 0;
 229 }
 230
 231 static int imx_get_trip_temp(struct thermal_zone_device *tz, int trip,
 232                              unsigned long *temp)
 233 {
 234         struct imx_thermal_data *data = tz->devdata;
 235
 236         *temp = (trip == IMX_TRIP_PASSIVE) ? data->temp_passive :
 237                                              data->temp_critical;
 238         return 0;
 239 }
 240
 241 static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip,
 242                              unsigned long temp)
 243 {
 244         struct imx_thermal_data *data = tz->devdata;
 245
 246         if (trip == IMX_TRIP_CRITICAL)
 247                 return -EPERM;
 248
 249         if (temp > IMX_TEMP_PASSIVE)
 250                 return -EINVAL;
 251
 252         data->temp_passive = temp;
 253
 254         imx_set_alarm_temp(data, temp);
 255
 256         return 0;
 257 }
 258
 259 static int imx_bind(struct thermal_zone_device *tz,
 260                     struct thermal_cooling_device *cdev)
 261 {
 262         int ret;
 263
 264         ret = thermal_zone_bind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev,
 265                                                THERMAL_NO_LIMIT,
 266                                                THERMAL_NO_LIMIT);
 267         if (ret) {
 268                 dev_err(&tz->device,
 269                         "binding zone %s with cdev %s failed:%d\n",
 270                         tz->type, cdev->type, ret);
 271                 return ret;
 272         }
 273
 274         return 0;
 275 }
 276
 277 static int imx_unbind(struct thermal_zone_device *tz,
 278                       struct thermal_cooling_device *cdev)
 279 {
 280         int ret;
 281
 282         ret = thermal_zone_unbind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev);
 283         if (ret) {
 284                 dev_err(&tz->device,
 285                         "unbinding zone %s with cdev %s failed:%d\n",
 286                         tz->type, cdev->type, ret);
 287                 return ret;
 288         }
 289
 290         return 0;
 291 }
 292
 293 static struct thermal_zone_device_ops imx_tz_ops = {
 294         .bind = imx_bind,
 295         .unbind = imx_unbind,
 296         .get_temp = imx_get_temp,
 297         .get_mode = imx_get_mode,
 298         .set_mode = imx_set_mode,
 299         .get_trip_type = imx_get_trip_type,
 300         .get_trip_temp = imx_get_trip_temp,
 301         .get_crit_temp = imx_get_crit_temp,
 302         .set_trip_temp = imx_set_trip_temp,
 303 };
 304
 305 static int imx_get_sensor_data(struct platform_device *pdev)
 306 {
 307         struct imx_thermal_data *data = platform_get_drvdata(pdev);
 308         struct regmap *map;
 309         int t1, t2, n1, n2;
 310         int ret;
 311         u32 val;
 312         u64 temp64;
 313
 314         map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
 315                                               "fsl,tempmon-data");
 316         if (IS_ERR(map)) {
 317                 ret = PTR_ERR(map);
 318                 dev_err(&pdev->dev, "failed to get sensor regmap: %d\n", ret);
 319                 return ret;
 320         }
 321
 322         ret = regmap_read(map, OCOTP_ANA1, &val);
 323         if (ret) {
 324                 dev_err(&pdev->dev, "failed to read sensor data: %d\n", ret);
 325                 return ret;
 326         }
 327
 328         if (val == 0 || val == ~0) {
 329                 dev_err(&pdev->dev, "invalid sensor calibration data\n");
 330                 return -EINVAL;
 331         }
 332
 333         /*
 334          * Sensor data layout:
 335          *   [31:20] - sensor value @ 25C
 336          *    [19:8] - sensor value of hot
 337          *     [7:0] - hot temperature value
 338          * Use universal formula now and only need sensor value @ 25C
 339          * slope = 0.4297157 - (0.0015976 * 25C fuse)
 340          */
 341         n1 = val >> 20;
 342         n2 = (val & 0xfff00) >> 8;
 343         t2 = val & 0xff;
 344         t1 = 25; /* t1 always 25C */
 345
 346         /*
 347          * Derived from linear interpolation:
 348          * slope = 0.4297157 - (0.0015976 * 25C fuse)
 349          * slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0
 350          * (Nmeas - n1) / (Tmeas - t1) = slope
 351          * We want to reduce this down to the minimum computation necessary
 352          * for each temperature read.  Also, we want Tmeas in millicelsius
 353          * and we don't want to lose precision from integer division. So...
 354          * Tmeas = (Nmeas - n1) / slope + t1
 355          * milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1
 356          * milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1
 357          * Let constant c1 = (-1000 / slope)
 358          * milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1
 359          * Let constant c2 = n1 *c1 + 1000 * t1
 360          * milli_Tmeas = c2 - Nmeas * c1
 361          */
 362         temp64 = FACTOR0;
 363         temp64 *= 1000;
 364         do_div(temp64, FACTOR1 * n1 - FACTOR2);
 365         data->c1 = temp64;
 366         data->c2 = n1 * data->c1 + 1000 * t1;
 367
 368         /*
 369          * Set the default passive cooling trip point to 20 °C below the
 370          * maximum die temperature. Can be changed from userspace.
 371          */
 372         data->temp_passive = 1000 * (t2 - 20);
 373
 374         /*
 375          * The maximum die temperature is t2, let's give 5 °C cushion
 376          * for noise and possible temperature rise between measurements.
 377          */
 378         data->temp_critical = 1000 * (t2 - 5);
 379
 380         return 0;
 381 }
 382
 383 static irqreturn_t imx_thermal_alarm_irq(int irq, void *dev)
 384 {
 385         struct imx_thermal_data *data = dev;
 386
 387         disable_irq_nosync(irq);
 388         data->irq_enabled = false;
 389
 390         return IRQ_WAKE_THREAD;
 391 }
 392
 393 static irqreturn_t imx_thermal_alarm_irq_thread(int irq, void *dev)
 394 {
 395         struct imx_thermal_data *data = dev;
 396
 397         dev_dbg(&data->tz->device, "THERMAL ALARM: T > %lu\n",
 398                 data->alarm_temp / 1000);
 399
 400         thermal_zone_device_update(data->tz);
 401
 402         return IRQ_HANDLED;
 403 }
 404
 405 static int imx_thermal_probe(struct platform_device *pdev)
 406 {
 407         struct imx_thermal_data *data;
 408         struct cpumask clip_cpus;
 409         struct regmap *map;
 410         int measure_freq;
 411         int ret;
 412
 413         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 414         if (!data)
 415                 return -ENOMEM;
 416
 417         map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon");
 418         if (IS_ERR(map)) {
 419                 ret = PTR_ERR(map);
 420                 dev_err(&pdev->dev, "failed to get tempmon regmap: %d\n", ret);
 421                 return ret;
 422         }
 423         data->tempmon = map;
 424
 425         data->irq = platform_get_irq(pdev, 0);
 426         if (data->irq < 0)
 427                 return data->irq;
 428
 429         ret = devm_request_threaded_irq(&pdev->dev, data->irq,
 430                         imx_thermal_alarm_irq, imx_thermal_alarm_irq_thread,
 431                         0, "imx_thermal", data);
 432         if (ret < 0) {
 433                 dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
 434                 return ret;
 435         }
 436
 437         platform_set_drvdata(pdev, data);
 438
 439         ret = imx_get_sensor_data(pdev);
 440         if (ret) {
 441                 dev_err(&pdev->dev, "failed to get sensor data\n");
 442                 return ret;
 443         }
 444
 445         /* Make sure sensor is in known good state for measurements */
 446         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 447         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 448         regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
 449         regmap_write(map, MISC0 + REG_SET, MISC0_REFTOP_SELBIASOFF);
 450         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 451
 452         cpumask_set_cpu(0, &clip_cpus);
 453         data->cdev = cpufreq_cooling_register(&clip_cpus);
 454         if (IS_ERR(data->cdev)) {
 455                 ret = PTR_ERR(data->cdev);
 456                 dev_err(&pdev->dev,
 457                         "failed to register cpufreq cooling device: %d\n", ret);
 458                 return ret;
 459         }
 460
 461         data->tz = thermal_zone_device_register("imx_thermal_zone",
 462                                                 IMX_TRIP_NUM,
 463                                                 BIT(IMX_TRIP_PASSIVE), data,
 464                                                 &imx_tz_ops, NULL,
 465                                                 IMX_PASSIVE_DELAY,
 466                                                 IMX_POLLING_DELAY);
 467         if (IS_ERR(data->tz)) {
 468                 ret = PTR_ERR(data->tz);
 469                 dev_err(&pdev->dev,
 470                         "failed to register thermal zone device %d\n", ret);
 471                 cpufreq_cooling_unregister(data->cdev);
 472                 return ret;
 473         }
 474
 475         data->thermal_clk = devm_clk_get(&pdev->dev, NULL);
 476         if (IS_ERR(data->thermal_clk)) {
 477                 dev_warn(&pdev->dev, "failed to get thermal clk!\n");
 478         } else {
 479                 /*
 480                  * Thermal sensor needs clk on to get correct value, normally
 481                  * we should enable its clk before taking measurement and disable
 482                  * clk after measurement is done, but if alarm function is enabled,
 483                  * hardware will auto measure the temperature periodically, so we
 484                  * need to keep the clk always on for alarm function.
 485                  */
 486                 ret = clk_prepare_enable(data->thermal_clk);
 487                 if (ret)
 488                         dev_warn(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
 489         }
 490
 491         /* Enable measurements at ~ 10 Hz */
 492         regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
 493         measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */
 494         regmap_write(map, TEMPSENSE1 + REG_SET, measure_freq);
 495         imx_set_alarm_temp(data, data->temp_passive);
 496         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 497         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 498
 499         data->irq_enabled = true;
 500         data->mode = THERMAL_DEVICE_ENABLED;
 501
 502         return 0;
 503 }
 504
 505 static int imx_thermal_remove(struct platform_device *pdev)
 506 {
 507         struct imx_thermal_data *data = platform_get_drvdata(pdev);
 508         struct regmap *map = data->tempmon;
 509
 510         /* Disable measurements */
 511         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 512         if (!IS_ERR(data->thermal_clk))
 513                 clk_disable_unprepare(data->thermal_clk);
 514
 515         thermal_zone_device_unregister(data->tz);
 516         cpufreq_cooling_unregister(data->cdev);
 517
 518         return 0;
 519 }
 520
 521 #ifdef CONFIG_PM_SLEEP
 522 static int imx_thermal_suspend(struct device *dev)
 523 {
 524         struct imx_thermal_data *data = dev_get_drvdata(dev);
 525         struct regmap *map = data->tempmon;
 526
 527         /*
 528          * Need to disable thermal sensor, otherwise, when thermal core
 529          * try to get temperature before thermal sensor resume, a wrong
 530          * temperature will be read as the thermal sensor is powered
 531          * down.
 532          */
 533         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 534         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 535         data->mode = THERMAL_DEVICE_DISABLED;
 536
 537         return 0;
 538 }
 539
 540 static int imx_thermal_resume(struct device *dev)
 541 {
 542         struct imx_thermal_data *data = dev_get_drvdata(dev);
 543         struct regmap *map = data->tempmon;
 544
 545         /* Enabled thermal sensor after resume */
 546         regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 547         regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
 548         data->mode = THERMAL_DEVICE_ENABLED;
 549
 550         return 0;
 551 }
 552 #endif
 553
 554 static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
 555                          imx_thermal_suspend, imx_thermal_resume);
 556
 557 static const struct of_device_id of_imx_thermal_match[] = {
 558         { .compatible = "fsl,imx6q-tempmon", },
 559         { /* end */ }
 560 };
 561 MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
 562
 563 static struct platform_driver imx_thermal = {
 564         .driver = {
 565                 .name   = "imx_thermal",
 566                 .owner  = THIS_MODULE,
 567                 .pm     = &imx_thermal_pm_ops,
 568                 .of_match_table = of_imx_thermal_match,
 569         },
 570         .probe          = imx_thermal_probe,
 571         .remove         = imx_thermal_remove,
 572 };
 573 module_platform_driver(imx_thermal);
 574
 575 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
 576 MODULE_DESCRIPTION("Thermal driver for Freescale i.MX SoCs");
 577 MODULE_LICENSE("GPL v2");
 578 MODULE_ALIAS("platform:imx-thermal");