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     5
  64
  65 /* default THCODE values if FUSEs are missing */
  66 static const int thcodes[TSC_MAX_NUM][3] = {
  67         { 3397, 2800, 2221 },
  68         { 3393, 2795, 2216 },
  69         { 3389, 2805, 2237 },
  70         { 3415, 2694, 2195 },
  71         { 3356, 2724, 2244 },
  72 };
  73
  74 /* Structure for thermal temperature calculation */
  75 struct equation_coefs {
  76         int a1;
  77         int b1;
  78         int a2;
  79         int b2;
  80 };
  81
  82 struct rcar_gen3_thermal_tsc {
  83         void __iomem *base;
  84         struct thermal_zone_device *zone;
  85         struct equation_coefs coef;
  86         int tj_t;
  87         unsigned 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]) * (ths_tj_1 - TJ_3))
 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         int 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 <= thcodes[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         u32 irqmsk = 0;
 211
 212         if (low != -INT_MAX) {
 213                 irqmsk |= IRQ_TEMPD1;
 214                 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
 215                                         rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
 216         }
 217
 218         if (high != INT_MAX) {
 219                 irqmsk |= IRQ_TEMP2;
 220                 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
 221                                         rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
 222         }
 223
 224         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, irqmsk);
 225
 226         return 0;
 227 }
 228
 229 static struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
 230         .get_temp       = rcar_gen3_thermal_get_temp,
 231         .set_trips      = rcar_gen3_thermal_set_trips,
 232 };
 233
 234 static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
 235 {
 236         struct rcar_gen3_thermal_priv *priv = data;
 237         unsigned int i;
 238         u32 status;
 239
 240         for (i = 0; i < priv->num_tscs; i++) {
 241                 status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
 242                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
 243                 if (status)
 244                         thermal_zone_device_update(priv->tscs[i]->zone,
 245                                                    THERMAL_EVENT_UNSPECIFIED);
 246         }
 247
 248         return IRQ_HANDLED;
 249 }
 250
 251 static const struct soc_device_attribute r8a7795es1[] = {
 252         { .soc_id = "r8a7795", .revision = "ES1.*" },
 253         { /* sentinel */ }
 254 };
 255
 256 static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
 257 {
 258         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  CTSR_THBGR);
 259         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  0x0);
 260
 261         usleep_range(1000, 2000);
 262
 263         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);
 264
 265         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 266         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 267         if (tsc->zone->ops->set_trips)
 268                 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN,
 269                                         IRQ_TEMPD1 | IRQ_TEMP2);
 270
 271         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 272                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
 273
 274         usleep_range(100, 200);
 275
 276         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 277                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
 278                                 CTSR_VMST | CTSR_THSST);
 279
 280         usleep_range(1000, 2000);
 281 }
 282
 283 static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
 284 {
 285         u32 reg_val;
 286
 287         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 288         reg_val &= ~THCTR_PONM;
 289         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 290
 291         usleep_range(1000, 2000);
 292
 293         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
 294         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 295         if (tsc->zone->ops->set_trips)
 296                 rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN,
 297                                         IRQ_TEMPD1 | IRQ_TEMP2);
 298
 299         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 300         reg_val |= THCTR_THSST;
 301         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 302
 303         usleep_range(1000, 2000);
 304 }
 305
 306 static const int rcar_gen3_ths_tj_1 = 126;
 307 static const int rcar_gen3_ths_tj_1_m3_w = 116;
 308 static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
 309         {
 310                 .compatible = "renesas,r8a774a1-thermal",
 311                 .data = &rcar_gen3_ths_tj_1_m3_w,
 312         },
 313         {
 314                 .compatible = "renesas,r8a774b1-thermal",
 315                 .data = &rcar_gen3_ths_tj_1,
 316         },
 317         {
 318                 .compatible = "renesas,r8a774e1-thermal",
 319                 .data = &rcar_gen3_ths_tj_1,
 320         },
 321         {
 322                 .compatible = "renesas,r8a7795-thermal",
 323                 .data = &rcar_gen3_ths_tj_1,
 324         },
 325         {
 326                 .compatible = "renesas,r8a7796-thermal",
 327                 .data = &rcar_gen3_ths_tj_1_m3_w,
 328         },
 329         {
 330                 .compatible = "renesas,r8a77961-thermal",
 331                 .data = &rcar_gen3_ths_tj_1_m3_w,
 332         },
 333         {
 334                 .compatible = "renesas,r8a77965-thermal",
 335                 .data = &rcar_gen3_ths_tj_1,
 336         },
 337         {
 338                 .compatible = "renesas,r8a77980-thermal",
 339                 .data = &rcar_gen3_ths_tj_1,
 340         },
 341         {
 342                 .compatible = "renesas,r8a779a0-thermal",
 343                 .data = &rcar_gen3_ths_tj_1,
 344         },
 345         {},
 346 };
 347 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
 348
 349 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
 350 {
 351         struct device *dev = &pdev->dev;
 352
 353         pm_runtime_put(dev);
 354         pm_runtime_disable(dev);
 355
 356         return 0;
 357 }
 358
 359 static void rcar_gen3_hwmon_action(void *data)
 360 {
 361         struct thermal_zone_device *zone = data;
 362
 363         thermal_remove_hwmon_sysfs(zone);
 364 }
 365
 366 static int rcar_gen3_thermal_request_irqs(struct rcar_gen3_thermal_priv *priv,
 367                                           struct platform_device *pdev)
 368 {
 369         struct device *dev = &pdev->dev;
 370         unsigned int i;
 371         char *irqname;
 372         int ret, irq;
 373
 374         for (i = 0; i < 2; i++) {
 375                 irq = platform_get_irq_optional(pdev, i);
 376                 if (irq < 0)
 377                         return irq;
 378
 379                 irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
 380                                          dev_name(dev), i);
 381                 if (!irqname)
 382                         return -ENOMEM;
 383
 384                 ret = devm_request_threaded_irq(dev, irq, NULL,
 385                                                 rcar_gen3_thermal_irq,
 386                                                 IRQF_ONESHOT, irqname, priv);
 387                 if (ret)
 388                         return ret;
 389         }
 390
 391         return 0;
 392 }
 393
 394 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 395 {
 396         struct rcar_gen3_thermal_priv *priv;
 397         struct device *dev = &pdev->dev;
 398         const int *ths_tj_1 = of_device_get_match_data(dev);
 399         struct resource *res;
 400         struct thermal_zone_device *zone;
 401         unsigned int i;
 402         int ret;
 403
 404         /* default values if FUSEs are missing */
 405         /* TODO: Read values from hardware on supported platforms */
 406         int ptat[3] = { 2631, 1509, 435 };
 407
 408         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 409         if (!priv)
 410                 return -ENOMEM;
 411
 412         priv->thermal_init = rcar_gen3_thermal_init;
 413         if (soc_device_match(r8a7795es1))
 414                 priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
 415
 416         platform_set_drvdata(pdev, priv);
 417
 418         if (rcar_gen3_thermal_request_irqs(priv, pdev))
 419                 rcar_gen3_tz_of_ops.set_trips = NULL;
 420
 421         pm_runtime_enable(dev);
 422         pm_runtime_get_sync(dev);
 423
 424         for (i = 0; i < TSC_MAX_NUM; i++) {
 425                 struct rcar_gen3_thermal_tsc *tsc;
 426
 427                 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 428                 if (!res)
 429                         break;
 430
 431                 tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
 432                 if (!tsc) {
 433                         ret = -ENOMEM;
 434                         goto error_unregister;
 435                 }
 436
 437                 tsc->base = devm_ioremap_resource(dev, res);
 438                 if (IS_ERR(tsc->base)) {
 439                         ret = PTR_ERR(tsc->base);
 440                         goto error_unregister;
 441                 }
 442                 tsc->id = i;
 443
 444                 priv->tscs[i] = tsc;
 445
 446                 zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
 447                                                             &rcar_gen3_tz_of_ops);
 448                 if (IS_ERR(zone)) {
 449                         dev_err(dev, "Can't register thermal zone\n");
 450                         ret = PTR_ERR(zone);
 451                         goto error_unregister;
 452                 }
 453                 tsc->zone = zone;
 454
 455                 priv->thermal_init(tsc);
 456                 rcar_gen3_thermal_calc_coefs(tsc, ptat, thcodes[i], *ths_tj_1);
 457
 458                 tsc->zone->tzp->no_hwmon = false;
 459                 ret = thermal_add_hwmon_sysfs(tsc->zone);
 460                 if (ret)
 461                         goto error_unregister;
 462
 463                 ret = devm_add_action_or_reset(dev, rcar_gen3_hwmon_action, zone);
 464                 if (ret)
 465                         goto error_unregister;
 466
 467                 ret = of_thermal_get_ntrips(tsc->zone);
 468                 if (ret < 0)
 469                         goto error_unregister;
 470
 471                 dev_info(dev, "TSC%u: Loaded %d trip points\n", i, ret);
 472         }
 473
 474         priv->num_tscs = i;
 475
 476         if (!priv->num_tscs) {
 477                 ret = -ENODEV;
 478                 goto error_unregister;
 479         }
 480
 481         return 0;
 482
 483 error_unregister:
 484         rcar_gen3_thermal_remove(pdev);
 485
 486         return ret;
 487 }
 488
 489 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 490 {
 491         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 492         unsigned int i;
 493
 494         for (i = 0; i < priv->num_tscs; i++) {
 495                 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 496                 struct thermal_zone_device *zone = tsc->zone;
 497
 498                 priv->thermal_init(tsc);
 499                 if (zone->ops->set_trips)
 500                         rcar_gen3_thermal_set_trips(tsc, zone->prev_low_trip,
 501                                                     zone->prev_high_trip);
 502         }
 503
 504         return 0;
 505 }
 506
 507 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, NULL,
 508                          rcar_gen3_thermal_resume);
 509
 510 static struct platform_driver rcar_gen3_thermal_driver = {
 511         .driver = {
 512                 .name   = "rcar_gen3_thermal",
 513                 .pm = &rcar_gen3_thermal_pm_ops,
 514                 .of_match_table = rcar_gen3_thermal_dt_ids,
 515         },
 516         .probe          = rcar_gen3_thermal_probe,
 517         .remove         = rcar_gen3_thermal_remove,
 518 };
 519 module_platform_driver(rcar_gen3_thermal_driver);
 520
 521 MODULE_LICENSE("GPL v2");
 522 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
 523 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");