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         /* Make sure we are inside specifications */
 186         if ((mcelsius < MCELSIUS(-40)) || (mcelsius > MCELSIUS(125)))
 187                 return -EIO;
 188
 189         /* Round value to device granularity setting */
 190         *temp = rcar_gen3_thermal_round(mcelsius);
 191
 192         return 0;
 193 }
 194
 195 static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
 196                                               int mcelsius)
 197 {
 198         int celsius, val;
 199
 200         celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
 201         if (celsius <= INT_FIXPT(tsc->tj_t))
 202                 val = celsius * tsc->coef.a1 + tsc->coef.b1;
 203         else
 204                 val = celsius * tsc->coef.a2 + tsc->coef.b2;
 205
 206         return INT_FIXPT(val);
 207 }
 208
 209 static int rcar_gen3_thermal_set_trips(void *devdata, int low, int high)
 210 {
 211         struct rcar_gen3_thermal_tsc *tsc = devdata;
 212
 213         low = clamp_val(low, -40000, 120000);
 214         high = clamp_val(high, -40000, 120000);
 215
 216         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
 217                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
 218
 219         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
 220                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
 221
 222         tsc->low = low;
 223         tsc->high = high;
 224
 225         return 0;
 226 }
 227
 228 static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
 229         .get_temp       = rcar_gen3_thermal_get_temp,
 230         .set_trips      = rcar_gen3_thermal_set_trips,
 231 };
 232
 233 static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
 234 {
 235         unsigned int i;
 236         u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;
 237
 238         for (i = 0; i < priv->num_tscs; i++)
 239                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
 240 }
 241
 242 static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
 243 {
 244         struct rcar_gen3_thermal_priv *priv = data;
 245         u32 status;
 246         int i;
 247
 248         for (i = 0; i < priv->num_tscs; i++) {
 249                 status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
 250                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
 251                 if (status)
 252                         thermal_zone_device_update(priv->tscs[i]->zone,
 253                                                    THERMAL_EVENT_UNSPECIFIED);
 254         }
 255
 256         return IRQ_HANDLED;
 257 }
 258
 259 static const struct soc_device_attribute r8a7795es1[] = {
 260         { .soc_id = "r8a7795", .revision = "ES1.*" },
 261         { /* sentinel */ }
 262 };
 263
 264 static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
 265 {
 266         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  CTSR_THBGR);
 267         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  0x0);
 268
 269         usleep_range(1000, 2000);
 270
 271         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);
 272
 273         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 274         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 275         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 276
 277         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 278                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
 279
 280         usleep_range(100, 200);
 281
 282         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 283                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
 284                                 CTSR_VMST | CTSR_THSST);
 285
 286         usleep_range(1000, 2000);
 287 }
 288
 289 static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
 290 {
 291         u32 reg_val;
 292
 293         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 294         reg_val &= ~THCTR_PONM;
 295         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 296
 297         usleep_range(1000, 2000);
 298
 299         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
 300         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 301         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 302
 303         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 304         reg_val |= THCTR_THSST;
 305         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 306
 307         usleep_range(1000, 2000);
 308 }
 309
 310 static const int rcar_gen3_ths_tj_1 = 126;
 311 static const int rcar_gen3_ths_tj_1_m3_w = 116;
 312 static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
 313         {
 314                 .compatible = "renesas,r8a774a1-thermal",
 315                 .data = &rcar_gen3_ths_tj_1_m3_w,
 316         },
 317         {
 318                 .compatible = "renesas,r8a7795-thermal",
 319                 .data = &rcar_gen3_ths_tj_1,
 320         },
 321         {
 322                 .compatible = "renesas,r8a7796-thermal",
 323                 .data = &rcar_gen3_ths_tj_1_m3_w,
 324         },
 325         {
 326                 .compatible = "renesas,r8a77965-thermal",
 327                 .data = &rcar_gen3_ths_tj_1,
 328         },
 329         {
 330                 .compatible = "renesas,r8a77980-thermal",
 331                 .data = &rcar_gen3_ths_tj_1,
 332         },
 333         {},
 334 };
 335 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
 336
 337 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
 338 {
 339         struct device *dev = &pdev->dev;
 340         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 341
 342         rcar_thermal_irq_set(priv, false);
 343
 344         pm_runtime_put(dev);
 345         pm_runtime_disable(dev);
 346
 347         return 0;
 348 }
 349
 350 static void rcar_gen3_hwmon_action(void *data)
 351 {
 352         struct thermal_zone_device *zone = data;
 353
 354         thermal_remove_hwmon_sysfs(zone);
 355 }
 356
 357 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 358 {
 359         struct rcar_gen3_thermal_priv *priv;
 360         struct device *dev = &pdev->dev;
 361         const int *rcar_gen3_ths_tj_1 = of_device_get_match_data(dev);
 362         struct resource *res;
 363         struct thermal_zone_device *zone;
 364         int ret, irq, i;
 365         char *irqname;
 366
 367         /* default values if FUSEs are missing */
 368         /* TODO: Read values from hardware on supported platforms */
 369         int ptat[3] = { 2631, 1509, 435 };
 370
 371         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 372         if (!priv)
 373                 return -ENOMEM;
 374
 375         priv->thermal_init = rcar_gen3_thermal_init;
 376         if (soc_device_match(r8a7795es1))
 377                 priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
 378
 379         platform_set_drvdata(pdev, priv);
 380
 381         /*
 382          * Request 2 (of the 3 possible) IRQs, the driver only needs to
 383          * to trigger on the low and high trip points of the current
 384          * temp window at this point.
 385          */
 386         for (i = 0; i < 2; i++) {
 387                 irq = platform_get_irq(pdev, i);
 388                 if (irq < 0)
 389                         return irq;
 390
 391                 irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
 392                                          dev_name(dev), i);
 393                 if (!irqname)
 394                         return -ENOMEM;
 395
 396                 ret = devm_request_threaded_irq(dev, irq, NULL,
 397                                                 rcar_gen3_thermal_irq,
 398                                                 IRQF_ONESHOT, irqname, priv);
 399                 if (ret)
 400                         return ret;
 401         }
 402
 403         pm_runtime_enable(dev);
 404         pm_runtime_get_sync(dev);
 405
 406         for (i = 0; i < TSC_MAX_NUM; i++) {
 407                 struct rcar_gen3_thermal_tsc *tsc;
 408
 409                 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 410                 if (!res)
 411                         break;
 412
 413                 tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
 414                 if (!tsc) {
 415                         ret = -ENOMEM;
 416                         goto error_unregister;
 417                 }
 418
 419                 tsc->base = devm_ioremap_resource(dev, res);
 420                 if (IS_ERR(tsc->base)) {
 421                         ret = PTR_ERR(tsc->base);
 422                         goto error_unregister;
 423                 }
 424                 tsc->id = i;
 425
 426                 priv->tscs[i] = tsc;
 427
 428                 priv->thermal_init(tsc);
 429                 rcar_gen3_thermal_calc_coefs(tsc, ptat, thcode[i],
 430                                              *rcar_gen3_ths_tj_1);
 431
 432                 zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
 433                                                             &rcar_gen3_tz_of_ops);
 434                 if (IS_ERR(zone)) {
 435                         dev_err(dev, "Can't register thermal zone\n");
 436                         ret = PTR_ERR(zone);
 437                         goto error_unregister;
 438                 }
 439                 tsc->zone = zone;
 440
 441                 tsc->zone->tzp->no_hwmon = false;
 442                 ret = thermal_add_hwmon_sysfs(tsc->zone);
 443                 if (ret)
 444                         goto error_unregister;
 445
 446                 ret = devm_add_action_or_reset(dev, rcar_gen3_hwmon_action, zone);
 447                 if (ret) {
 448                         goto error_unregister;
 449                 }
 450
 451                 ret = of_thermal_get_ntrips(tsc->zone);
 452                 if (ret < 0)
 453                         goto error_unregister;
 454
 455                 dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
 456         }
 457
 458         priv->num_tscs = i;
 459
 460         if (!priv->num_tscs) {
 461                 ret = -ENODEV;
 462                 goto error_unregister;
 463         }
 464
 465         rcar_thermal_irq_set(priv, true);
 466
 467         return 0;
 468
 469 error_unregister:
 470         rcar_gen3_thermal_remove(pdev);
 471
 472         return ret;
 473 }
 474
 475 static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
 476 {
 477         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 478
 479         rcar_thermal_irq_set(priv, false);
 480
 481         return 0;
 482 }
 483
 484 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 485 {
 486         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 487         unsigned int i;
 488
 489         for (i = 0; i < priv->num_tscs; i++) {
 490                 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 491
 492                 priv->thermal_init(tsc);
 493                 rcar_gen3_thermal_set_trips(tsc, tsc->low, tsc->high);
 494         }
 495
 496         rcar_thermal_irq_set(priv, true);
 497
 498         return 0;
 499 }
 500
 501 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
 502                          rcar_gen3_thermal_resume);
 503
 504 static struct platform_driver rcar_gen3_thermal_driver = {
 505         .driver = {
 506                 .name   = "rcar_gen3_thermal",
 507                 .pm = &rcar_gen3_thermal_pm_ops,
 508                 .of_match_table = rcar_gen3_thermal_dt_ids,
 509         },
 510         .probe          = rcar_gen3_thermal_probe,
 511         .remove         = rcar_gen3_thermal_remove,
 512 };
 513 module_platform_driver(rcar_gen3_thermal_driver);
 514
 515 MODULE_LICENSE("GPL v2");
 516 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
 517 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");