drivers/thermal/st/stm_thermal.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
   4  * Author: David Hernandez Sanchez <david.hernandezsanchez@st.com> for
   5  * STMicroelectronics.
   6  */
   7
   8 #include <linux/clk.h>
   9 #include <linux/clk-provider.h>
  10 #include <linux/delay.h>
  11 #include <linux/err.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/io.h>
  14 #include <linux/iopoll.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/of_device.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/thermal.h>
  21
  22 #include "../thermal_core.h"
  23 #include "../thermal_hwmon.h"
  24
  25 /* DTS register offsets */
  26 #define DTS_CFGR1_OFFSET        0x0
  27 #define DTS_T0VALR1_OFFSET      0x8
  28 #define DTS_RAMPVALR_OFFSET     0X10
  29 #define DTS_ITR1_OFFSET         0x14
  30 #define DTS_DR_OFFSET           0x1C
  31 #define DTS_SR_OFFSET           0x20
  32 #define DTS_ITENR_OFFSET        0x24
  33 #define DTS_CIFR_OFFSET         0x28
  34
  35 /* DTS_CFGR1 register mask definitions */
  36 #define HSREF_CLK_DIV_MASK      GENMASK(30, 24)
  37 #define TS1_SMP_TIME_MASK       GENMASK(19, 16)
  38 #define TS1_INTRIG_SEL_MASK     GENMASK(11, 8)
  39
  40 /* DTS_T0VALR1 register mask definitions */
  41 #define TS1_T0_MASK             GENMASK(17, 16)
  42 #define TS1_FMT0_MASK           GENMASK(15, 0)
  43
  44 /* DTS_RAMPVALR register mask definitions */
  45 #define TS1_RAMP_COEFF_MASK     GENMASK(15, 0)
  46
  47 /* DTS_ITR1 register mask definitions */
  48 #define TS1_HITTHD_MASK         GENMASK(31, 16)
  49 #define TS1_LITTHD_MASK         GENMASK(15, 0)
  50
  51 /* DTS_DR register mask definitions */
  52 #define TS1_MFREQ_MASK          GENMASK(15, 0)
  53
  54 /* Less significant bit position definitions */
  55 #define TS1_T0_POS              16
  56 #define TS1_SMP_TIME_POS        16
  57 #define TS1_HITTHD_POS          16
  58 #define HSREF_CLK_DIV_POS       24
  59
  60 /* DTS_CFGR1 bit definitions */
  61 #define TS1_EN                  BIT(0)
  62 #define TS1_START               BIT(4)
  63 #define REFCLK_SEL              BIT(20)
  64 #define REFCLK_LSE              REFCLK_SEL
  65 #define Q_MEAS_OPT              BIT(21)
  66 #define CALIBRATION_CONTROL     Q_MEAS_OPT
  67
  68 /* DTS_SR bit definitions */
  69 #define TS_RDY                  BIT(15)
  70 /* Bit definitions below are common for DTS_SR, DTS_ITENR and DTS_CIFR */
  71 #define HIGH_THRESHOLD          BIT(2)
  72 #define LOW_THRESHOLD           BIT(1)
  73
  74 /* Constants */
  75 #define ADJUST                  100
  76 #define ONE_MHZ                 1000000
  77 #define POLL_TIMEOUT            5000
  78 #define STARTUP_TIME            40
  79 #define TS1_T0_VAL0             30
  80 #define TS1_T0_VAL1             130
  81 #define NO_HW_TRIG              0
  82
  83 /* The Thermal Framework expects millidegrees */
  84 #define mcelsius(temp)          ((temp) * 1000)
  85
  86 /* The Sensor expects oC degrees */
  87 #define celsius(temp)           ((temp) / 1000)
  88
  89 struct stm_thermal_sensor {
  90         struct device *dev;
  91         struct thermal_zone_device *th_dev;
  92         enum thermal_device_mode mode;
  93         struct clk *clk;
  94         int high_temp;
  95         int low_temp;
  96         int temp_critical;
  97         int temp_passive;
  98         unsigned int low_temp_enabled;
  99         int num_trips;
 100         int irq;
 101         unsigned int irq_enabled;
 102         void __iomem *base;
 103         int t0, fmt0, ramp_coeff;
 104 };
 105
 106 static irqreturn_t stm_thermal_alarm_irq(int irq, void *sdata)
 107 {
 108         struct stm_thermal_sensor *sensor = sdata;
 109
 110         disable_irq_nosync(irq);
 111         sensor->irq_enabled = false;
 112
 113         return IRQ_WAKE_THREAD;
 114 }
 115
 116 static irqreturn_t stm_thermal_alarm_irq_thread(int irq, void *sdata)
 117 {
 118         u32 value;
 119         struct stm_thermal_sensor *sensor = sdata;
 120
 121         /* read IT reason in SR and clear flags */
 122         value = readl_relaxed(sensor->base + DTS_SR_OFFSET);
 123
 124         if ((value & LOW_THRESHOLD) == LOW_THRESHOLD)
 125                 writel_relaxed(LOW_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
 126
 127         if ((value & HIGH_THRESHOLD) == HIGH_THRESHOLD)
 128                 writel_relaxed(HIGH_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
 129
 130         thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED);
 131
 132         return IRQ_HANDLED;
 133 }
 134
 135 static int stm_sensor_power_on(struct stm_thermal_sensor *sensor)
 136 {
 137         int ret;
 138         u32 value;
 139
 140         /* Enable sensor */
 141         value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
 142         value |= TS1_EN;
 143         writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
 144
 145         /*
 146          * The DTS block can be enabled by setting TSx_EN bit in
 147          * DTS_CFGRx register. It requires a startup time of
 148          * 40μs. Use 5 ms as arbitrary timeout.
 149          */
 150         ret = readl_poll_timeout(sensor->base + DTS_SR_OFFSET,
 151                                  value, (value & TS_RDY),
 152                                  STARTUP_TIME, POLL_TIMEOUT);
 153         if (ret)
 154                 return ret;
 155
 156         /* Start continuous measuring */
 157         value = readl_relaxed(sensor->base +
 158                               DTS_CFGR1_OFFSET);
 159         value |= TS1_START;
 160         writel_relaxed(value, sensor->base +
 161                        DTS_CFGR1_OFFSET);
 162
 163         return 0;
 164 }
 165
 166 static int stm_sensor_power_off(struct stm_thermal_sensor *sensor)
 167 {
 168         u32 value;
 169
 170         /* Stop measuring */
 171         value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
 172         value &= ~TS1_START;
 173         writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
 174
 175         /* Ensure stop is taken into account */
 176         usleep_range(STARTUP_TIME, POLL_TIMEOUT);
 177
 178         /* Disable sensor */
 179         value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
 180         value &= ~TS1_EN;
 181         writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
 182
 183         /* Ensure disable is taken into account */
 184         return readl_poll_timeout(sensor->base + DTS_SR_OFFSET, value,
 185                                   !(value & TS_RDY),
 186                                   STARTUP_TIME, POLL_TIMEOUT);
 187 }
 188
 189 static int stm_thermal_calibration(struct stm_thermal_sensor *sensor)
 190 {
 191         u32 value, clk_freq;
 192         u32 prescaler;
 193
 194         /* Figure out prescaler value for PCLK during calibration */
 195         clk_freq = clk_get_rate(sensor->clk);
 196         if (!clk_freq)
 197                 return -EINVAL;
 198
 199         prescaler = 0;
 200         clk_freq /= ONE_MHZ;
 201         if (clk_freq) {
 202                 while (prescaler <= clk_freq)
 203                         prescaler++;
 204         }
 205
 206         value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
 207
 208         /* Clear prescaler */
 209         value &= ~HSREF_CLK_DIV_MASK;
 210
 211         /* Set prescaler. pclk_freq/prescaler < 1MHz */
 212         value |= (prescaler << HSREF_CLK_DIV_POS);
 213
 214         /* Select PCLK as reference clock */
 215         value &= ~REFCLK_SEL;
 216
 217         /* Set maximal sampling time for better precision */
 218         value |= TS1_SMP_TIME_MASK;
 219
 220         /* Measure with calibration */
 221         value &= ~CALIBRATION_CONTROL;
 222
 223         /* select trigger */
 224         value &= ~TS1_INTRIG_SEL_MASK;
 225         value |= NO_HW_TRIG;
 226
 227         writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
 228
 229         return 0;
 230 }
 231
 232 /* Fill in DTS structure with factory sensor values */
 233 static int stm_thermal_read_factory_settings(struct stm_thermal_sensor *sensor)
 234 {
 235         /* Retrieve engineering calibration temperature */
 236         sensor->t0 = readl_relaxed(sensor->base + DTS_T0VALR1_OFFSET) &
 237                                         TS1_T0_MASK;
 238         if (!sensor->t0)
 239                 sensor->t0 = TS1_T0_VAL0;
 240         else
 241                 sensor->t0 = TS1_T0_VAL1;
 242
 243         /* Retrieve fmt0 and put it on Hz */
 244         sensor->fmt0 = ADJUST * readl_relaxed(sensor->base + DTS_T0VALR1_OFFSET)
 245                                               & TS1_FMT0_MASK;
 246
 247         /* Retrieve ramp coefficient */
 248         sensor->ramp_coeff = readl_relaxed(sensor->base + DTS_RAMPVALR_OFFSET) &
 249                                            TS1_RAMP_COEFF_MASK;
 250
 251         if (!sensor->fmt0 || !sensor->ramp_coeff) {
 252                 dev_err(sensor->dev, "%s: wrong setting\n", __func__);
 253                 return -EINVAL;
 254         }
 255
 256         dev_dbg(sensor->dev, "%s: T0 = %doC, FMT0 = %dHz, RAMP_COEFF = %dHz/oC",
 257                 __func__, sensor->t0, sensor->fmt0, sensor->ramp_coeff);
 258
 259         return 0;
 260 }
 261
 262 static int stm_thermal_calculate_threshold(struct stm_thermal_sensor *sensor,
 263                                            int temp, u32 *th)
 264 {
 265         int freqM;
 266         u32 sampling_time;
 267
 268         /* Retrieve the number of periods to sample */
 269         sampling_time = (readl_relaxed(sensor->base + DTS_CFGR1_OFFSET) &
 270                         TS1_SMP_TIME_MASK) >> TS1_SMP_TIME_POS;
 271
 272         /* Figure out the CLK_PTAT frequency for a given temperature */
 273         freqM = ((temp - sensor->t0) * sensor->ramp_coeff)
 274                  + sensor->fmt0;
 275
 276         dev_dbg(sensor->dev, "%s: freqM for threshold = %d Hz",
 277                 __func__, freqM);
 278
 279         /* Figure out the threshold sample number */
 280         *th = clk_get_rate(sensor->clk);
 281         if (!*th)
 282                 return -EINVAL;
 283
 284         *th = *th / freqM;
 285
 286         *th *= sampling_time;
 287
 288         return 0;
 289 }
 290
 291 static int stm_thermal_set_threshold(struct stm_thermal_sensor *sensor)
 292 {
 293         u32 value, th;
 294         int ret;
 295
 296         value = readl_relaxed(sensor->base + DTS_ITR1_OFFSET);
 297
 298         /* Erase threshold content */
 299         value &= ~(TS1_LITTHD_MASK | TS1_HITTHD_MASK);
 300
 301         /* Retrieve the sample threshold number th for a given temperature */
 302         ret = stm_thermal_calculate_threshold(sensor, sensor->high_temp, &th);
 303         if (ret)
 304                 return ret;
 305
 306         value |= th & TS1_LITTHD_MASK;
 307
 308         if (sensor->low_temp_enabled) {
 309                 /* Retrieve the sample threshold */
 310                 ret = stm_thermal_calculate_threshold(sensor, sensor->low_temp,
 311                                                       &th);
 312                 if (ret)
 313                         return ret;
 314
 315                 value |= (TS1_HITTHD_MASK  & (th << TS1_HITTHD_POS));
 316         }
 317
 318         /* Write value on the Low interrupt threshold */
 319         writel_relaxed(value, sensor->base + DTS_ITR1_OFFSET);
 320
 321         return 0;
 322 }
 323
 324 /* Disable temperature interrupt */
 325 static int stm_disable_irq(struct stm_thermal_sensor *sensor)
 326 {
 327         u32 value;
 328
 329         /* Disable IT generation for low and high thresholds */
 330         value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
 331         writel_relaxed(value & ~(LOW_THRESHOLD | HIGH_THRESHOLD),
 332                        sensor->base + DTS_ITENR_OFFSET);
 333
 334         dev_dbg(sensor->dev, "%s: IT disabled on sensor side", __func__);
 335
 336         return 0;
 337 }
 338
 339 /* Enable temperature interrupt */
 340 static int stm_enable_irq(struct stm_thermal_sensor *sensor)
 341 {
 342         u32 value;
 343
 344         /*
 345          * Code below enables High temperature threshold using a low threshold
 346          * sampling value
 347          */
 348
 349         /* Make sure LOW_THRESHOLD IT is clear before enabling */
 350         writel_relaxed(LOW_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
 351
 352         /* Enable IT generation for low threshold */
 353         value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
 354         value |= LOW_THRESHOLD;
 355
 356         /* Enable the low temperature threshold if needed */
 357         if (sensor->low_temp_enabled) {
 358                 /* Make sure HIGH_THRESHOLD IT is clear before enabling */
 359                 writel_relaxed(HIGH_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
 360
 361                 /* Enable IT generation for high threshold */
 362                 value |= HIGH_THRESHOLD;
 363         }
 364
 365         /* Enable thresholds */
 366         writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET);
 367
 368         dev_dbg(sensor->dev, "%s: IT enabled on sensor side", __func__);
 369
 370         return 0;
 371 }
 372
 373 static int stm_thermal_update_threshold(struct stm_thermal_sensor *sensor)
 374 {
 375         int ret;
 376
 377         sensor->mode = THERMAL_DEVICE_DISABLED;
 378
 379         ret = stm_sensor_power_off(sensor);
 380         if (ret)
 381                 return ret;
 382
 383         ret = stm_disable_irq(sensor);
 384         if (ret)
 385                 return ret;
 386
 387         ret = stm_thermal_set_threshold(sensor);
 388         if (ret)
 389                 return ret;
 390
 391         ret = stm_enable_irq(sensor);
 392         if (ret)
 393                 return ret;
 394
 395         ret = stm_sensor_power_on(sensor);
 396         if (ret)
 397                 return ret;
 398
 399         sensor->mode = THERMAL_DEVICE_ENABLED;
 400
 401         return 0;
 402 }
 403
 404 /* Callback to get temperature from HW */
 405 static int stm_thermal_get_temp(void *data, int *temp)
 406 {
 407         struct stm_thermal_sensor *sensor = data;
 408         u32 sampling_time;
 409         int freqM, ret;
 410
 411         if (sensor->mode != THERMAL_DEVICE_ENABLED)
 412                 return -EAGAIN;
 413
 414         /* Retrieve the number of samples */
 415         ret = readl_poll_timeout(sensor->base + DTS_DR_OFFSET, freqM,
 416                                  (freqM & TS1_MFREQ_MASK), STARTUP_TIME,
 417                                  POLL_TIMEOUT);
 418
 419         if (ret)
 420                 return ret;
 421
 422         if (!freqM)
 423                 return -ENODATA;
 424
 425         /* Retrieve the number of periods sampled */
 426         sampling_time = (readl_relaxed(sensor->base + DTS_CFGR1_OFFSET) &
 427                         TS1_SMP_TIME_MASK) >> TS1_SMP_TIME_POS;
 428
 429         /* Figure out the number of samples per period */
 430         freqM /= sampling_time;
 431
 432         /* Figure out the CLK_PTAT frequency */
 433         freqM = clk_get_rate(sensor->clk) / freqM;
 434         if (!freqM)
 435                 return -EINVAL;
 436
 437         dev_dbg(sensor->dev, "%s: freqM=%d\n", __func__, freqM);
 438
 439         /* Figure out the temperature in mili celsius */
 440         *temp = mcelsius(sensor->t0 + ((freqM - sensor->fmt0) /
 441                          sensor->ramp_coeff));
 442
 443         dev_dbg(sensor->dev, "%s: temperature = %d millicelsius",
 444                 __func__, *temp);
 445
 446         /* Update thresholds */
 447         if (sensor->num_trips > 1) {
 448                 /* Update alarm threshold value to next higher trip point */
 449                 if (sensor->high_temp == sensor->temp_passive &&
 450                     celsius(*temp) >= sensor->temp_passive) {
 451                         sensor->high_temp = sensor->temp_critical;
 452                         sensor->low_temp = sensor->temp_passive;
 453                         sensor->low_temp_enabled = true;
 454                         ret = stm_thermal_update_threshold(sensor);
 455                         if (ret)
 456                                 return ret;
 457                 }
 458
 459                 if (sensor->high_temp == sensor->temp_critical &&
 460                     celsius(*temp) < sensor->temp_passive) {
 461                         sensor->high_temp = sensor->temp_passive;
 462                         sensor->low_temp_enabled = false;
 463                         ret = stm_thermal_update_threshold(sensor);
 464                         if (ret)
 465                                 return ret;
 466                 }
 467
 468                 /*
 469                  * Re-enable alarm IRQ if temperature below critical
 470                  * temperature
 471                  */
 472                 if (!sensor->irq_enabled &&
 473                     (celsius(*temp) < sensor->temp_critical)) {
 474                         sensor->irq_enabled = true;
 475                         enable_irq(sensor->irq);
 476                 }
 477         }
 478
 479         return 0;
 480 }
 481
 482 /* Registers DTS irq to be visible by GIC */
 483 static int stm_register_irq(struct stm_thermal_sensor *sensor)
 484 {
 485         struct device *dev = sensor->dev;
 486         struct platform_device *pdev = to_platform_device(dev);
 487         int ret;
 488
 489         sensor->irq = platform_get_irq(pdev, 0);
 490         if (sensor->irq < 0) {
 491                 dev_err(dev, "%s: Unable to find IRQ\n", __func__);
 492                 return sensor->irq;
 493         }
 494
 495         ret = devm_request_threaded_irq(dev, sensor->irq,
 496                                         stm_thermal_alarm_irq,
 497                                         stm_thermal_alarm_irq_thread,
 498                                         IRQF_ONESHOT,
 499                                         dev->driver->name, sensor);
 500         if (ret) {
 501                 dev_err(dev, "%s: Failed to register IRQ %d\n", __func__,
 502                         sensor->irq);
 503                 return ret;
 504         }
 505
 506         sensor->irq_enabled = true;
 507
 508         dev_dbg(dev, "%s: thermal IRQ registered", __func__);
 509
 510         return 0;
 511 }
 512
 513 static int stm_thermal_sensor_off(struct stm_thermal_sensor *sensor)
 514 {
 515         int ret;
 516
 517         ret = stm_sensor_power_off(sensor);
 518         if (ret)
 519                 return ret;
 520
 521         clk_disable_unprepare(sensor->clk);
 522
 523         return 0;
 524 }
 525
 526 static int stm_thermal_prepare(struct stm_thermal_sensor *sensor)
 527 {
 528         int ret;
 529         struct device *dev = sensor->dev;
 530
 531         ret = clk_prepare_enable(sensor->clk);
 532         if (ret)
 533                 return ret;
 534
 535         ret = stm_thermal_calibration(sensor);
 536         if (ret)
 537                 goto thermal_unprepare;
 538
 539         /* Set threshold(s) for IRQ */
 540         ret = stm_thermal_set_threshold(sensor);
 541         if (ret)
 542                 goto thermal_unprepare;
 543
 544         ret = stm_enable_irq(sensor);
 545         if (ret)
 546                 goto thermal_unprepare;
 547
 548         ret = stm_sensor_power_on(sensor);
 549         if (ret) {
 550                 dev_err(dev, "%s: failed to power on sensor\n", __func__);
 551                 goto irq_disable;
 552         }
 553
 554         return 0;
 555
 556 irq_disable:
 557         stm_disable_irq(sensor);
 558
 559 thermal_unprepare:
 560         clk_disable_unprepare(sensor->clk);
 561
 562         return ret;
 563 }
 564
 565 #ifdef CONFIG_PM_SLEEP
 566 static int stm_thermal_suspend(struct device *dev)
 567 {
 568         int ret;
 569         struct platform_device *pdev = to_platform_device(dev);
 570         struct stm_thermal_sensor *sensor = platform_get_drvdata(pdev);
 571
 572         ret = stm_thermal_sensor_off(sensor);
 573         if (ret)
 574                 return ret;
 575
 576         sensor->mode = THERMAL_DEVICE_DISABLED;
 577
 578         return 0;
 579 }
 580
 581 static int stm_thermal_resume(struct device *dev)
 582 {
 583         int ret;
 584         struct platform_device *pdev = to_platform_device(dev);
 585         struct stm_thermal_sensor *sensor = platform_get_drvdata(pdev);
 586
 587         ret = stm_thermal_prepare(sensor);
 588         if (ret)
 589                 return ret;
 590
 591         sensor->mode = THERMAL_DEVICE_ENABLED;
 592
 593         return 0;
 594 }
 595 #endif /* CONFIG_PM_SLEEP */
 596
 597 SIMPLE_DEV_PM_OPS(stm_thermal_pm_ops, stm_thermal_suspend, stm_thermal_resume);
 598
 599 static const struct thermal_zone_of_device_ops stm_tz_ops = {
 600         .get_temp       = stm_thermal_get_temp,
 601 };
 602
 603 static const struct of_device_id stm_thermal_of_match[] = {
 604                 { .compatible = "st,stm32-thermal"},
 605         { /* sentinel */ }
 606 };
 607 MODULE_DEVICE_TABLE(of, stm_thermal_of_match);
 608
 609 static int stm_thermal_probe(struct platform_device *pdev)
 610 {
 611         struct stm_thermal_sensor *sensor;
 612         struct resource *res;
 613         const struct thermal_trip *trip;
 614         void __iomem *base;
 615         int ret, i;
 616
 617         if (!pdev->dev.of_node) {
 618                 dev_err(&pdev->dev, "%s: device tree node not found\n",
 619                         __func__);
 620                 return -EINVAL;
 621         }
 622
 623         sensor = devm_kzalloc(&pdev->dev, sizeof(*sensor), GFP_KERNEL);
 624         if (!sensor)
 625                 return -ENOMEM;
 626
 627         platform_set_drvdata(pdev, sensor);
 628
 629         sensor->dev = &pdev->dev;
 630
 631         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 632         base = devm_ioremap_resource(&pdev->dev, res);
 633         if (IS_ERR(base))
 634                 return PTR_ERR(base);
 635
 636         /* Populate sensor */
 637         sensor->base = base;
 638
 639         ret = stm_thermal_read_factory_settings(sensor);
 640         if (ret)
 641                 return ret;
 642
 643         sensor->clk = devm_clk_get(&pdev->dev, "pclk");
 644         if (IS_ERR(sensor->clk)) {
 645                 dev_err(&pdev->dev, "%s: failed to fetch PCLK clock\n",
 646                         __func__);
 647                 return PTR_ERR(sensor->clk);
 648         }
 649
 650         /* Register IRQ into GIC */
 651         ret = stm_register_irq(sensor);
 652         if (ret)
 653                 return ret;
 654
 655         sensor->th_dev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0,
 656                                                               sensor,
 657                                                               &stm_tz_ops);
 658
 659         if (IS_ERR(sensor->th_dev)) {
 660                 dev_err(&pdev->dev, "%s: thermal zone sensor registering KO\n",
 661                         __func__);
 662                 ret = PTR_ERR(sensor->th_dev);
 663                 return ret;
 664         }
 665
 666         if (!sensor->th_dev->ops->get_crit_temp) {
 667                 /* Critical point must be provided */
 668                 ret = -EINVAL;
 669                 goto err_tz;
 670         }
 671
 672         ret = sensor->th_dev->ops->get_crit_temp(sensor->th_dev,
 673                         &sensor->temp_critical);
 674         if (ret) {
 675                 dev_err(&pdev->dev,
 676                         "Not able to read critical_temp: %d\n", ret);
 677                 goto err_tz;
 678         }
 679
 680         sensor->temp_critical = celsius(sensor->temp_critical);
 681
 682         /* Set thresholds for IRQ */
 683         sensor->high_temp = sensor->temp_critical;
 684
 685         trip = of_thermal_get_trip_points(sensor->th_dev);
 686         sensor->num_trips = of_thermal_get_ntrips(sensor->th_dev);
 687
 688         /* Find out passive temperature if it exists */
 689         for (i = (sensor->num_trips - 1); i >= 0;  i--) {
 690                 if (trip[i].type == THERMAL_TRIP_PASSIVE) {
 691                         sensor->temp_passive = celsius(trip[i].temperature);
 692                         /* Update high temperature threshold */
 693                         sensor->high_temp = sensor->temp_passive;
 694                         }
 695         }
 696
 697         /*
 698          * Ensure low_temp_enabled flag is disabled.
 699          * By disabling low_temp_enabled, low threshold IT will not be
 700          * configured neither enabled because it is not needed as high
 701          * threshold is set on the lowest temperature trip point after
 702          * probe.
 703          */
 704         sensor->low_temp_enabled = false;
 705
 706         /* Configure and enable HW sensor */
 707         ret = stm_thermal_prepare(sensor);
 708         if (ret) {
 709                 dev_err(&pdev->dev,
 710                         "Not able to enable sensor: %d\n", ret);
 711                 goto err_tz;
 712         }
 713
 714         /*
 715          * Thermal_zone doesn't enable hwmon as default,
 716          * enable it here
 717          */
 718         sensor->th_dev->tzp->no_hwmon = false;
 719         ret = thermal_add_hwmon_sysfs(sensor->th_dev);
 720         if (ret)
 721                 goto err_tz;
 722
 723         sensor->mode = THERMAL_DEVICE_ENABLED;
 724
 725         dev_info(&pdev->dev, "%s: Driver initialized successfully\n",
 726                  __func__);
 727
 728         return 0;
 729
 730 err_tz:
 731         thermal_zone_of_sensor_unregister(&pdev->dev, sensor->th_dev);
 732         return ret;
 733 }
 734
 735 static int stm_thermal_remove(struct platform_device *pdev)
 736 {
 737         struct stm_thermal_sensor *sensor = platform_get_drvdata(pdev);
 738
 739         stm_thermal_sensor_off(sensor);
 740         thermal_remove_hwmon_sysfs(sensor->th_dev);
 741         thermal_zone_of_sensor_unregister(&pdev->dev, sensor->th_dev);
 742
 743         return 0;
 744 }
 745
 746 static struct platform_driver stm_thermal_driver = {
 747         .driver = {
 748                 .name   = "stm_thermal",
 749                 .pm     = &stm_thermal_pm_ops,
 750                 .of_match_table = stm_thermal_of_match,
 751         },
 752         .probe          = stm_thermal_probe,
 753         .remove         = stm_thermal_remove,
 754 };
 755 module_platform_driver(stm_thermal_driver);
 756
 757 MODULE_DESCRIPTION("STMicroelectronics STM32 Thermal Sensor Driver");
 758 MODULE_AUTHOR("David Hernandez Sanchez <david.hernandezsanchez@st.com>");
 759 MODULE_LICENSE("GPL v2");
 760 MODULE_ALIAS("platform:stm_thermal");