drivers/thermal/rcar_gen3_thermal.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  R-Car Gen3 THS thermal sensor driver
   4  *  Based on rcar_thermal.c and work from Hien Dang and Khiem Nguyen.
   5  *
   6  * Copyright (C) 2016 Renesas Electronics Corporation.
   7  * Copyright (C) 2016 Sang Engineering
   8  */
   9 #include <linux/delay.h>
  10 #include <linux/err.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/io.h>
  13 #include <linux/module.h>
  14 #include <linux/of_device.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/pm_runtime.h>
  17 #include <linux/sys_soc.h>
  18 #include <linux/thermal.h>
  19
  20 #include "thermal_core.h"
  21 #include "thermal_hwmon.h"
  22
  23 /* Register offsets */
  24 #define REG_GEN3_IRQSTR         0x04
  25 #define REG_GEN3_IRQMSK         0x08
  26 #define REG_GEN3_IRQCTL         0x0C
  27 #define REG_GEN3_IRQEN          0x10
  28 #define REG_GEN3_IRQTEMP1       0x14
  29 #define REG_GEN3_IRQTEMP2       0x18
  30 #define REG_GEN3_IRQTEMP3       0x1C
  31 #define REG_GEN3_CTSR           0x20
  32 #define REG_GEN3_THCTR          0x20
  33 #define REG_GEN3_TEMP           0x28
  34 #define REG_GEN3_THCODE1        0x50
  35 #define REG_GEN3_THCODE2        0x54
  36 #define REG_GEN3_THCODE3        0x58
  37
  38 /* IRQ{STR,MSK,EN} bits */
  39 #define IRQ_TEMP1               BIT(0)
  40 #define IRQ_TEMP2               BIT(1)
  41 #define IRQ_TEMP3               BIT(2)
  42 #define IRQ_TEMPD1              BIT(3)
  43 #define IRQ_TEMPD2              BIT(4)
  44 #define IRQ_TEMPD3              BIT(5)
  45
  46 /* CTSR bits */
  47 #define CTSR_PONM       BIT(8)
  48 #define CTSR_AOUT       BIT(7)
  49 #define CTSR_THBGR      BIT(5)
  50 #define CTSR_VMEN       BIT(4)
  51 #define CTSR_VMST       BIT(1)
  52 #define CTSR_THSST      BIT(0)
  53
  54 /* THCTR bits */
  55 #define THCTR_PONM      BIT(6)
  56 #define THCTR_THSST     BIT(0)
  57
  58 #define CTEMP_MASK      0xFFF
  59
  60 #define MCELSIUS(temp)  ((temp) * 1000)
  61 #define GEN3_FUSE_MASK  0xFFF
  62
  63 #define TSC_MAX_NUM     3
  64
  65 /* default THCODE values if FUSEs are missing */
  66 static const int thcode[TSC_MAX_NUM][3] = {
  67         { 3397, 2800, 2221 },
  68         { 3393, 2795, 2216 },
  69         { 3389, 2805, 2237 },
  70 };
  71
  72 /* Structure for thermal temperature calculation */
  73 struct equation_coefs {
  74         int a1;
  75         int b1;
  76         int a2;
  77         int b2;
  78 };
  79
  80 struct rcar_gen3_thermal_tsc {
  81         void __iomem *base;
  82         struct thermal_zone_device *zone;
  83         struct equation_coefs coef;
  84         int low;
  85         int high;
  86         int tj_t;
  87         int id; /* thermal channel id */
  88 };
  89
  90 struct rcar_gen3_thermal_priv {
  91         struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
  92         unsigned int num_tscs;
  93         void (*thermal_init)(struct rcar_gen3_thermal_tsc *tsc);
  94 };
  95
  96 static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
  97                                          u32 reg)
  98 {
  99         return ioread32(tsc->base + reg);
 100 }
 101
 102 static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc,
 103                                            u32 reg, u32 data)
 104 {
 105         iowrite32(data, tsc->base + reg);
 106 }
 107
 108 /*
 109  * Linear approximation for temperature
 110  *
 111  * [reg] = [temp] * a + b => [temp] = ([reg] - b) / a
 112  *
 113  * The constants a and b are calculated using two triplets of int values PTAT
 114  * and THCODE. PTAT and THCODE can either be read from hardware or use hard
 115  * coded values from driver. The formula to calculate a and b are taken from
 116  * BSP and sparsely documented and understood.
 117  *
 118  * Examining the linear formula and the formula used to calculate constants a
 119  * and b while knowing that the span for PTAT and THCODE values are between
 120  * 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001.
 121  * Integer also needs to be signed so that leaves 7 bits for binary
 122  * fixed point scaling.
 123  */
 124
 125 #define FIXPT_SHIFT 7
 126 #define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT)
 127 #define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT)
 128 #define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b))
 129 #define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT)
 130
 131 #define RCAR3_THERMAL_GRAN 500 /* mili Celsius */
 132
 133 /* no idea where these constants come from */
 134 #define TJ_3 -41
 135
 136 static void rcar_gen3_thermal_calc_coefs(struct rcar_gen3_thermal_tsc *tsc,
 137                                          int *ptat, const int *thcode,
 138                                          int ths_tj_1)
 139 {
 140         /* TODO: Find documentation and document constant calculation formula */
 141
 142         /*
 143          * Division is not scaled in BSP and if scaled it might overflow
 144          * the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled
 145          */
 146         tsc->tj_t = (FIXPT_INT((ptat[1] - ptat[2]) * 157)
 147                      / (ptat[0] - ptat[2])) + FIXPT_INT(TJ_3);
 148
 149         tsc->coef.a1 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[2]),
 150                                  tsc->tj_t - FIXPT_INT(TJ_3));
 151         tsc->coef.b1 = FIXPT_INT(thcode[2]) - tsc->coef.a1 * TJ_3;
 152
 153         tsc->coef.a2 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[0]),
 154                                  tsc->tj_t - FIXPT_INT(ths_tj_1));
 155         tsc->coef.b2 = FIXPT_INT(thcode[0]) - tsc->coef.a2 * ths_tj_1;
 156 }
 157
 158 static int rcar_gen3_thermal_round(int temp)
 159 {
 160         int result, round_offs;
 161
 162         round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 :
 163                 -RCAR3_THERMAL_GRAN / 2;
 164         result = (temp + round_offs) / RCAR3_THERMAL_GRAN;
 165         return result * RCAR3_THERMAL_GRAN;
 166 }
 167
 168 static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
 169 {
 170         struct rcar_gen3_thermal_tsc *tsc = devdata;
 171         int mcelsius, val;
 172         u32 reg;
 173
 174         /* Read register and convert to mili Celsius */
 175         reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;
 176
 177         if (reg <= thcode[tsc->id][1])
 178                 val = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1,
 179                                 tsc->coef.a1);
 180         else
 181                 val = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2,
 182                                 tsc->coef.a2);
 183         mcelsius = FIXPT_TO_MCELSIUS(val);
 184
 185         /* Guaranteed operating range is -40C to 125C. */
 186
 187         /* Round value to device granularity setting */
 188         *temp = rcar_gen3_thermal_round(mcelsius);
 189
 190         return 0;
 191 }
 192
 193 static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
 194                                               int mcelsius)
 195 {
 196         int celsius, val;
 197
 198         celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
 199         if (celsius <= INT_FIXPT(tsc->tj_t))
 200                 val = celsius * tsc->coef.a1 + tsc->coef.b1;
 201         else
 202                 val = celsius * tsc->coef.a2 + tsc->coef.b2;
 203
 204         return INT_FIXPT(val);
 205 }
 206
 207 static int rcar_gen3_thermal_set_trips(void *devdata, int low, int high)
 208 {
 209         struct rcar_gen3_thermal_tsc *tsc = devdata;
 210
 211         low = clamp_val(low, -40000, 120000);
 212         high = clamp_val(high, -40000, 120000);
 213
 214         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
 215                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
 216
 217         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
 218                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
 219
 220         tsc->low = low;
 221         tsc->high = high;
 222
 223         return 0;
 224 }
 225
 226 static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
 227         .get_temp       = rcar_gen3_thermal_get_temp,
 228         .set_trips      = rcar_gen3_thermal_set_trips,
 229 };
 230
 231 static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
 232 {
 233         unsigned int i;
 234         u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;
 235
 236         for (i = 0; i < priv->num_tscs; i++)
 237                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
 238 }
 239
 240 static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
 241 {
 242         struct rcar_gen3_thermal_priv *priv = data;
 243         u32 status;
 244         int i;
 245
 246         for (i = 0; i < priv->num_tscs; i++) {
 247                 status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
 248                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
 249                 if (status)
 250                         thermal_zone_device_update(priv->tscs[i]->zone,
 251                                                    THERMAL_EVENT_UNSPECIFIED);
 252         }
 253
 254         return IRQ_HANDLED;
 255 }
 256
 257 static const struct soc_device_attribute r8a7795es1[] = {
 258         { .soc_id = "r8a7795", .revision = "ES1.*" },
 259         { /* sentinel */ }
 260 };
 261
 262 static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
 263 {
 264         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  CTSR_THBGR);
 265         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  0x0);
 266
 267         usleep_range(1000, 2000);
 268
 269         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);
 270
 271         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 272         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 273         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 274
 275         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 276                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
 277
 278         usleep_range(100, 200);
 279
 280         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 281                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
 282                                 CTSR_VMST | CTSR_THSST);
 283
 284         usleep_range(1000, 2000);
 285 }
 286
 287 static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
 288 {
 289         u32 reg_val;
 290
 291         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 292         reg_val &= ~THCTR_PONM;
 293         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 294
 295         usleep_range(1000, 2000);
 296
 297         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
 298         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 299         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 300
 301         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 302         reg_val |= THCTR_THSST;
 303         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 304
 305         usleep_range(1000, 2000);
 306 }
 307
 308 static const int rcar_gen3_ths_tj_1 = 126;
 309 static const int rcar_gen3_ths_tj_1_m3_w = 116;
 310 static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
 311         {
 312                 .compatible = "renesas,r8a774a1-thermal",
 313                 .data = &rcar_gen3_ths_tj_1_m3_w,
 314         },
 315         {
 316                 .compatible = "renesas,r8a774b1-thermal",
 317                 .data = &rcar_gen3_ths_tj_1,
 318         },
 319         {
 320                 .compatible = "renesas,r8a7795-thermal",
 321                 .data = &rcar_gen3_ths_tj_1,
 322         },
 323         {
 324                 .compatible = "renesas,r8a7796-thermal",
 325                 .data = &rcar_gen3_ths_tj_1_m3_w,
 326         },
 327         {
 328                 .compatible = "renesas,r8a77965-thermal",
 329                 .data = &rcar_gen3_ths_tj_1,
 330         },
 331         {
 332                 .compatible = "renesas,r8a77980-thermal",
 333                 .data = &rcar_gen3_ths_tj_1,
 334         },
 335         {},
 336 };
 337 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
 338
 339 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
 340 {
 341         struct device *dev = &pdev->dev;
 342         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 343
 344         rcar_thermal_irq_set(priv, false);
 345
 346         pm_runtime_put(dev);
 347         pm_runtime_disable(dev);
 348
 349         return 0;
 350 }
 351
 352 static void rcar_gen3_hwmon_action(void *data)
 353 {
 354         struct thermal_zone_device *zone = data;
 355
 356         thermal_remove_hwmon_sysfs(zone);
 357 }
 358
 359 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 360 {
 361         struct rcar_gen3_thermal_priv *priv;
 362         struct device *dev = &pdev->dev;
 363         const int *rcar_gen3_ths_tj_1 = of_device_get_match_data(dev);
 364         struct resource *res;
 365         struct thermal_zone_device *zone;
 366         int ret, irq, i;
 367         char *irqname;
 368
 369         /* default values if FUSEs are missing */
 370         /* TODO: Read values from hardware on supported platforms */
 371         int ptat[3] = { 2631, 1509, 435 };
 372
 373         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 374         if (!priv)
 375                 return -ENOMEM;
 376
 377         priv->thermal_init = rcar_gen3_thermal_init;
 378         if (soc_device_match(r8a7795es1))
 379                 priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
 380
 381         platform_set_drvdata(pdev, priv);
 382
 383         /*
 384          * Request 2 (of the 3 possible) IRQs, the driver only needs to
 385          * to trigger on the low and high trip points of the current
 386          * temp window at this point.
 387          */
 388         for (i = 0; i < 2; i++) {
 389                 irq = platform_get_irq(pdev, i);
 390                 if (irq < 0)
 391                         return irq;
 392
 393                 irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
 394                                          dev_name(dev), i);
 395                 if (!irqname)
 396                         return -ENOMEM;
 397
 398                 ret = devm_request_threaded_irq(dev, irq, NULL,
 399                                                 rcar_gen3_thermal_irq,
 400                                                 IRQF_ONESHOT, irqname, priv);
 401                 if (ret)
 402                         return ret;
 403         }
 404
 405         pm_runtime_enable(dev);
 406         pm_runtime_get_sync(dev);
 407
 408         for (i = 0; i < TSC_MAX_NUM; i++) {
 409                 struct rcar_gen3_thermal_tsc *tsc;
 410
 411                 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 412                 if (!res)
 413                         break;
 414
 415                 tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
 416                 if (!tsc) {
 417                         ret = -ENOMEM;
 418                         goto error_unregister;
 419                 }
 420
 421                 tsc->base = devm_ioremap_resource(dev, res);
 422                 if (IS_ERR(tsc->base)) {
 423                         ret = PTR_ERR(tsc->base);
 424                         goto error_unregister;
 425                 }
 426                 tsc->id = i;
 427
 428                 priv->tscs[i] = tsc;
 429
 430                 priv->thermal_init(tsc);
 431                 rcar_gen3_thermal_calc_coefs(tsc, ptat, thcode[i],
 432                                              *rcar_gen3_ths_tj_1);
 433
 434                 zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
 435                                                             &rcar_gen3_tz_of_ops);
 436                 if (IS_ERR(zone)) {
 437                         dev_err(dev, "Can't register thermal zone\n");
 438                         ret = PTR_ERR(zone);
 439                         goto error_unregister;
 440                 }
 441                 tsc->zone = zone;
 442
 443                 tsc->zone->tzp->no_hwmon = false;
 444                 ret = thermal_add_hwmon_sysfs(tsc->zone);
 445                 if (ret)
 446                         goto error_unregister;
 447
 448                 ret = devm_add_action_or_reset(dev, rcar_gen3_hwmon_action, zone);
 449                 if (ret) {
 450                         goto error_unregister;
 451                 }
 452
 453                 ret = of_thermal_get_ntrips(tsc->zone);
 454                 if (ret < 0)
 455                         goto error_unregister;
 456
 457                 dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
 458         }
 459
 460         priv->num_tscs = i;
 461
 462         if (!priv->num_tscs) {
 463                 ret = -ENODEV;
 464                 goto error_unregister;
 465         }
 466
 467         rcar_thermal_irq_set(priv, true);
 468
 469         return 0;
 470
 471 error_unregister:
 472         rcar_gen3_thermal_remove(pdev);
 473
 474         return ret;
 475 }
 476
 477 static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
 478 {
 479         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 480
 481         rcar_thermal_irq_set(priv, false);
 482
 483         return 0;
 484 }
 485
 486 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 487 {
 488         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 489         unsigned int i;
 490
 491         for (i = 0; i < priv->num_tscs; i++) {
 492                 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 493
 494                 priv->thermal_init(tsc);
 495                 rcar_gen3_thermal_set_trips(tsc, tsc->low, tsc->high);
 496         }
 497
 498         rcar_thermal_irq_set(priv, true);
 499
 500         return 0;
 501 }
 502
 503 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
 504                          rcar_gen3_thermal_resume);
 505
 506 static struct platform_driver rcar_gen3_thermal_driver = {
 507         .driver = {
 508                 .name   = "rcar_gen3_thermal",
 509                 .pm = &rcar_gen3_thermal_pm_ops,
 510                 .of_match_table = rcar_gen3_thermal_dt_ids,
 511         },
 512         .probe          = rcar_gen3_thermal_probe,
 513         .remove         = rcar_gen3_thermal_remove,
 514 };
 515 module_platform_driver(rcar_gen3_thermal_driver);
 516
 517 MODULE_LICENSE("GPL v2");
 518 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
 519 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");