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/thermal.h>
  18
  19 #include "thermal_hwmon.h"
  20
  21 /* Register offsets */
  22 #define REG_GEN3_IRQSTR         0x04
  23 #define REG_GEN3_IRQMSK         0x08
  24 #define REG_GEN3_IRQCTL         0x0C
  25 #define REG_GEN3_IRQEN          0x10
  26 #define REG_GEN3_IRQTEMP1       0x14
  27 #define REG_GEN3_IRQTEMP2       0x18
  28 #define REG_GEN3_IRQTEMP3       0x1C
  29 #define REG_GEN3_THCTR          0x20
  30 #define REG_GEN3_TEMP           0x28
  31 #define REG_GEN3_THCODE1        0x50
  32 #define REG_GEN3_THCODE2        0x54
  33 #define REG_GEN3_THCODE3        0x58
  34 #define REG_GEN3_PTAT1          0x5c
  35 #define REG_GEN3_PTAT2          0x60
  36 #define REG_GEN3_PTAT3          0x64
  37 #define REG_GEN3_THSCP          0x68
  38
  39 /* IRQ{STR,MSK,EN} bits */
  40 #define IRQ_TEMP1               BIT(0)
  41 #define IRQ_TEMP2               BIT(1)
  42 #define IRQ_TEMP3               BIT(2)
  43 #define IRQ_TEMPD1              BIT(3)
  44 #define IRQ_TEMPD2              BIT(4)
  45 #define IRQ_TEMPD3              BIT(5)
  46
  47 /* THCTR bits */
  48 #define THCTR_PONM      BIT(6)
  49 #define THCTR_THSST     BIT(0)
  50
  51 /* THSCP bits */
  52 #define THSCP_COR_PARA_VLD      (BIT(15) | BIT(14))
  53
  54 #define CTEMP_MASK      0xFFF
  55
  56 #define MCELSIUS(temp)  ((temp) * 1000)
  57 #define GEN3_FUSE_MASK  0xFFF
  58
  59 #define TSC_MAX_NUM     5
  60
  61 /* Structure for thermal temperature calculation */
  62 struct equation_coefs {
  63         int a1;
  64         int b1;
  65         int a2;
  66         int b2;
  67 };
  68
  69 struct rcar_gen3_thermal_tsc {
  70         void __iomem *base;
  71         struct thermal_zone_device *zone;
  72         struct equation_coefs coef;
  73         int tj_t;
  74         int thcode[3];
  75 };
  76
  77 struct rcar_gen3_thermal_priv {
  78         struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
  79         struct thermal_zone_device_ops ops;
  80         unsigned int num_tscs;
  81         int ptat[3];
  82 };
  83
  84 static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
  85                                          u32 reg)
  86 {
  87         return ioread32(tsc->base + reg);
  88 }
  89
  90 static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc,
  91                                            u32 reg, u32 data)
  92 {
  93         iowrite32(data, tsc->base + reg);
  94 }
  95
  96 /*
  97  * Linear approximation for temperature
  98  *
  99  * [reg] = [temp] * a + b => [temp] = ([reg] - b) / a
 100  *
 101  * The constants a and b are calculated using two triplets of int values PTAT
 102  * and THCODE. PTAT and THCODE can either be read from hardware or use hard
 103  * coded values from driver. The formula to calculate a and b are taken from
 104  * BSP and sparsely documented and understood.
 105  *
 106  * Examining the linear formula and the formula used to calculate constants a
 107  * and b while knowing that the span for PTAT and THCODE values are between
 108  * 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001.
 109  * Integer also needs to be signed so that leaves 7 bits for binary
 110  * fixed point scaling.
 111  */
 112
 113 #define FIXPT_SHIFT 7
 114 #define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT)
 115 #define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT)
 116 #define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b))
 117 #define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT)
 118
 119 #define RCAR3_THERMAL_GRAN 500 /* mili Celsius */
 120
 121 /* no idea where these constants come from */
 122 #define TJ_3 -41
 123
 124 static void rcar_gen3_thermal_calc_coefs(struct rcar_gen3_thermal_priv *priv,
 125                                          struct rcar_gen3_thermal_tsc *tsc,
 126                                          int ths_tj_1)
 127 {
 128         /* TODO: Find documentation and document constant calculation formula */
 129
 130         /*
 131          * Division is not scaled in BSP and if scaled it might overflow
 132          * the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled
 133          */
 134         tsc->tj_t = (FIXPT_INT((priv->ptat[1] - priv->ptat[2]) * (ths_tj_1 - TJ_3))
 135                      / (priv->ptat[0] - priv->ptat[2])) + FIXPT_INT(TJ_3);
 136
 137         tsc->coef.a1 = FIXPT_DIV(FIXPT_INT(tsc->thcode[1] - tsc->thcode[2]),
 138                                  tsc->tj_t - FIXPT_INT(TJ_3));
 139         tsc->coef.b1 = FIXPT_INT(tsc->thcode[2]) - tsc->coef.a1 * TJ_3;
 140
 141         tsc->coef.a2 = FIXPT_DIV(FIXPT_INT(tsc->thcode[1] - tsc->thcode[0]),
 142                                  tsc->tj_t - FIXPT_INT(ths_tj_1));
 143         tsc->coef.b2 = FIXPT_INT(tsc->thcode[0]) - tsc->coef.a2 * ths_tj_1;
 144 }
 145
 146 static int rcar_gen3_thermal_round(int temp)
 147 {
 148         int result, round_offs;
 149
 150         round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 :
 151                 -RCAR3_THERMAL_GRAN / 2;
 152         result = (temp + round_offs) / RCAR3_THERMAL_GRAN;
 153         return result * RCAR3_THERMAL_GRAN;
 154 }
 155
 156 static int rcar_gen3_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
 157 {
 158         struct rcar_gen3_thermal_tsc *tsc = thermal_zone_device_priv(tz);
 159         int mcelsius, val;
 160         int reg;
 161
 162         /* Read register and convert to mili Celsius */
 163         reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;
 164
 165         if (reg <= tsc->thcode[1])
 166                 val = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1,
 167                                 tsc->coef.a1);
 168         else
 169                 val = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2,
 170                                 tsc->coef.a2);
 171         mcelsius = FIXPT_TO_MCELSIUS(val);
 172
 173         /* Guaranteed operating range is -40C to 125C. */
 174
 175         /* Round value to device granularity setting */
 176         *temp = rcar_gen3_thermal_round(mcelsius);
 177
 178         return 0;
 179 }
 180
 181 static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
 182                                               int mcelsius)
 183 {
 184         int celsius, val;
 185
 186         celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
 187         if (celsius <= INT_FIXPT(tsc->tj_t))
 188                 val = celsius * tsc->coef.a1 + tsc->coef.b1;
 189         else
 190                 val = celsius * tsc->coef.a2 + tsc->coef.b2;
 191
 192         return INT_FIXPT(val);
 193 }
 194
 195 static int rcar_gen3_thermal_set_trips(struct thermal_zone_device *tz, int low, int high)
 196 {
 197         struct rcar_gen3_thermal_tsc *tsc = thermal_zone_device_priv(tz);
 198         u32 irqmsk = 0;
 199
 200         if (low != -INT_MAX) {
 201                 irqmsk |= IRQ_TEMPD1;
 202                 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
 203                                         rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
 204         }
 205
 206         if (high != INT_MAX) {
 207                 irqmsk |= IRQ_TEMP2;
 208                 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
 209                                         rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
 210         }
 211
 212         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, irqmsk);
 213
 214         return 0;
 215 }
 216
 217 static const struct thermal_zone_device_ops rcar_gen3_tz_of_ops = {
 218         .get_temp       = rcar_gen3_thermal_get_temp,
 219         .set_trips      = rcar_gen3_thermal_set_trips,
 220 };
 221
 222 static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
 223 {
 224         struct rcar_gen3_thermal_priv *priv = data;
 225         unsigned int i;
 226         u32 status;
 227
 228         for (i = 0; i < priv->num_tscs; i++) {
 229                 status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
 230                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
 231                 if (status && priv->tscs[i]->zone)
 232                         thermal_zone_device_update(priv->tscs[i]->zone,
 233                                                    THERMAL_EVENT_UNSPECIFIED);
 234         }
 235
 236         return IRQ_HANDLED;
 237 }
 238
 239 static bool rcar_gen3_thermal_read_fuses(struct rcar_gen3_thermal_priv *priv)
 240 {
 241         unsigned int i;
 242         u32 thscp;
 243
 244         /* If fuses are not set, fallback to pseudo values. */
 245         thscp = rcar_gen3_thermal_read(priv->tscs[0], REG_GEN3_THSCP);
 246         if ((thscp & THSCP_COR_PARA_VLD) != THSCP_COR_PARA_VLD) {
 247                 /* Default THCODE values in case FUSEs are not set. */
 248                 static const int thcodes[TSC_MAX_NUM][3] = {
 249                         { 3397, 2800, 2221 },
 250                         { 3393, 2795, 2216 },
 251                         { 3389, 2805, 2237 },
 252                         { 3415, 2694, 2195 },
 253                         { 3356, 2724, 2244 },
 254                 };
 255
 256                 priv->ptat[0] = 2631;
 257                 priv->ptat[1] = 1509;
 258                 priv->ptat[2] = 435;
 259
 260                 for (i = 0; i < priv->num_tscs; i++) {
 261                         struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 262
 263                         tsc->thcode[0] = thcodes[i][0];
 264                         tsc->thcode[1] = thcodes[i][1];
 265                         tsc->thcode[2] = thcodes[i][2];
 266                 }
 267
 268                 return false;
 269         }
 270
 271         /*
 272          * Set the pseudo calibration points with fused values.
 273          * PTAT is shared between all TSCs but only fused for the first
 274          * TSC while THCODEs are fused for each TSC.
 275          */
 276         priv->ptat[0] = rcar_gen3_thermal_read(priv->tscs[0], REG_GEN3_PTAT1) &
 277                 GEN3_FUSE_MASK;
 278         priv->ptat[1] = rcar_gen3_thermal_read(priv->tscs[0], REG_GEN3_PTAT2) &
 279                 GEN3_FUSE_MASK;
 280         priv->ptat[2] = rcar_gen3_thermal_read(priv->tscs[0], REG_GEN3_PTAT3) &
 281                 GEN3_FUSE_MASK;
 282
 283         for (i = 0; i < priv->num_tscs; i++) {
 284                 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 285
 286                 tsc->thcode[0] = rcar_gen3_thermal_read(tsc, REG_GEN3_THCODE1) &
 287                         GEN3_FUSE_MASK;
 288                 tsc->thcode[1] = rcar_gen3_thermal_read(tsc, REG_GEN3_THCODE2) &
 289                         GEN3_FUSE_MASK;
 290                 tsc->thcode[2] = rcar_gen3_thermal_read(tsc, REG_GEN3_THCODE3) &
 291                         GEN3_FUSE_MASK;
 292         }
 293
 294         return true;
 295 }
 296
 297 static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_priv *priv,
 298                                    struct rcar_gen3_thermal_tsc *tsc)
 299 {
 300         u32 reg_val;
 301
 302         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 303         reg_val &= ~THCTR_PONM;
 304         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 305
 306         usleep_range(1000, 2000);
 307
 308         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
 309         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 310         if (priv->ops.set_trips)
 311                 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN,
 312                                         IRQ_TEMPD1 | IRQ_TEMP2);
 313
 314         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 315         reg_val |= THCTR_THSST;
 316         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 317
 318         usleep_range(1000, 2000);
 319 }
 320
 321 static const int rcar_gen3_ths_tj_1 = 126;
 322 static const int rcar_gen3_ths_tj_1_m3_w = 116;
 323 static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
 324         {
 325                 .compatible = "renesas,r8a774a1-thermal",
 326                 .data = &rcar_gen3_ths_tj_1_m3_w,
 327         },
 328         {
 329                 .compatible = "renesas,r8a774b1-thermal",
 330                 .data = &rcar_gen3_ths_tj_1,
 331         },
 332         {
 333                 .compatible = "renesas,r8a774e1-thermal",
 334                 .data = &rcar_gen3_ths_tj_1,
 335         },
 336         {
 337                 .compatible = "renesas,r8a7795-thermal",
 338                 .data = &rcar_gen3_ths_tj_1,
 339         },
 340         {
 341                 .compatible = "renesas,r8a7796-thermal",
 342                 .data = &rcar_gen3_ths_tj_1_m3_w,
 343         },
 344         {
 345                 .compatible = "renesas,r8a77961-thermal",
 346                 .data = &rcar_gen3_ths_tj_1_m3_w,
 347         },
 348         {
 349                 .compatible = "renesas,r8a77965-thermal",
 350                 .data = &rcar_gen3_ths_tj_1,
 351         },
 352         {
 353                 .compatible = "renesas,r8a77980-thermal",
 354                 .data = &rcar_gen3_ths_tj_1,
 355         },
 356         {
 357                 .compatible = "renesas,r8a779a0-thermal",
 358                 .data = &rcar_gen3_ths_tj_1,
 359         },
 360         {
 361                 .compatible = "renesas,r8a779f0-thermal",
 362                 .data = &rcar_gen3_ths_tj_1,
 363         },
 364         {
 365                 .compatible = "renesas,r8a779g0-thermal",
 366                 .data = &rcar_gen3_ths_tj_1,
 367         },
 368         {},
 369 };
 370 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
 371
 372 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
 373 {
 374         struct device *dev = &pdev->dev;
 375
 376         pm_runtime_put(dev);
 377         pm_runtime_disable(dev);
 378
 379         return 0;
 380 }
 381
 382 static void rcar_gen3_hwmon_action(void *data)
 383 {
 384         struct thermal_zone_device *zone = data;
 385
 386         thermal_remove_hwmon_sysfs(zone);
 387 }
 388
 389 static int rcar_gen3_thermal_request_irqs(struct rcar_gen3_thermal_priv *priv,
 390                                           struct platform_device *pdev)
 391 {
 392         struct device *dev = &pdev->dev;
 393         unsigned int i;
 394         char *irqname;
 395         int ret, irq;
 396
 397         for (i = 0; i < 2; i++) {
 398                 irq = platform_get_irq_optional(pdev, i);
 399                 if (irq < 0)
 400                         return irq;
 401
 402                 irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
 403                                          dev_name(dev), i);
 404                 if (!irqname)
 405                         return -ENOMEM;
 406
 407                 ret = devm_request_threaded_irq(dev, irq, NULL,
 408                                                 rcar_gen3_thermal_irq,
 409                                                 IRQF_ONESHOT, irqname, priv);
 410                 if (ret)
 411                         return ret;
 412         }
 413
 414         return 0;
 415 }
 416
 417 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 418 {
 419         struct rcar_gen3_thermal_priv *priv;
 420         struct device *dev = &pdev->dev;
 421         const int *ths_tj_1 = of_device_get_match_data(dev);
 422         struct resource *res;
 423         struct thermal_zone_device *zone;
 424         unsigned int i;
 425         int ret;
 426
 427         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 428         if (!priv)
 429                 return -ENOMEM;
 430
 431         priv->ops = rcar_gen3_tz_of_ops;
 432
 433         platform_set_drvdata(pdev, priv);
 434
 435         if (rcar_gen3_thermal_request_irqs(priv, pdev))
 436                 priv->ops.set_trips = NULL;
 437
 438         pm_runtime_enable(dev);
 439         pm_runtime_get_sync(dev);
 440
 441         for (i = 0; i < TSC_MAX_NUM; i++) {
 442                 struct rcar_gen3_thermal_tsc *tsc;
 443
 444                 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 445                 if (!res)
 446                         break;
 447
 448                 tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
 449                 if (!tsc) {
 450                         ret = -ENOMEM;
 451                         goto error_unregister;
 452                 }
 453
 454                 tsc->base = devm_ioremap_resource(dev, res);
 455                 if (IS_ERR(tsc->base)) {
 456                         ret = PTR_ERR(tsc->base);
 457                         goto error_unregister;
 458                 }
 459
 460                 priv->tscs[i] = tsc;
 461         }
 462
 463         priv->num_tscs = i;
 464
 465         if (!rcar_gen3_thermal_read_fuses(priv))
 466                 dev_info(dev, "No calibration values fused, fallback to driver values\n");
 467
 468         for (i = 0; i < priv->num_tscs; i++) {
 469                 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 470
 471                 rcar_gen3_thermal_init(priv, tsc);
 472                 rcar_gen3_thermal_calc_coefs(priv, tsc, *ths_tj_1);
 473
 474                 zone = devm_thermal_of_zone_register(dev, i, tsc, &priv->ops);
 475                 if (IS_ERR(zone)) {
 476                         dev_err(dev, "Sensor %u: Can't register thermal zone\n", i);
 477                         ret = PTR_ERR(zone);
 478                         goto error_unregister;
 479                 }
 480                 tsc->zone = zone;
 481
 482                 ret = thermal_add_hwmon_sysfs(tsc->zone);
 483                 if (ret)
 484                         goto error_unregister;
 485
 486                 ret = devm_add_action_or_reset(dev, rcar_gen3_hwmon_action, zone);
 487                 if (ret)
 488                         goto error_unregister;
 489
 490                 ret = thermal_zone_get_num_trips(tsc->zone);
 491                 if (ret < 0)
 492                         goto error_unregister;
 493
 494                 dev_info(dev, "Sensor %u: Loaded %d trip points\n", i, ret);
 495         }
 496
 497         if (!priv->num_tscs) {
 498                 ret = -ENODEV;
 499                 goto error_unregister;
 500         }
 501
 502         return 0;
 503
 504 error_unregister:
 505         rcar_gen3_thermal_remove(pdev);
 506
 507         return ret;
 508 }
 509
 510 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 511 {
 512         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 513         unsigned int i;
 514
 515         for (i = 0; i < priv->num_tscs; i++) {
 516                 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 517
 518                 rcar_gen3_thermal_init(priv, tsc);
 519         }
 520
 521         return 0;
 522 }
 523
 524 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, NULL,
 525                          rcar_gen3_thermal_resume);
 526
 527 static struct platform_driver rcar_gen3_thermal_driver = {
 528         .driver = {
 529                 .name   = "rcar_gen3_thermal",
 530                 .pm = &rcar_gen3_thermal_pm_ops,
 531                 .of_match_table = rcar_gen3_thermal_dt_ids,
 532         },
 533         .probe          = rcar_gen3_thermal_probe,
 534         .remove         = rcar_gen3_thermal_remove,
 535 };
 536 module_platform_driver(rcar_gen3_thermal_driver);
 537
 538 MODULE_LICENSE("GPL v2");
 539 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
 540 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");