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/spinlock.h>
  18 #include <linux/sys_soc.h>
  19 #include <linux/thermal.h>
  20
  21 #include "thermal_core.h"
  22 #include "thermal_hwmon.h"
  23
  24 /* Register offsets */
  25 #define REG_GEN3_IRQSTR         0x04
  26 #define REG_GEN3_IRQMSK         0x08
  27 #define REG_GEN3_IRQCTL         0x0C
  28 #define REG_GEN3_IRQEN          0x10
  29 #define REG_GEN3_IRQTEMP1       0x14
  30 #define REG_GEN3_IRQTEMP2       0x18
  31 #define REG_GEN3_IRQTEMP3       0x1C
  32 #define REG_GEN3_CTSR           0x20
  33 #define REG_GEN3_THCTR          0x20
  34 #define REG_GEN3_TEMP           0x28
  35 #define REG_GEN3_THCODE1        0x50
  36 #define REG_GEN3_THCODE2        0x54
  37 #define REG_GEN3_THCODE3        0x58
  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 /* CTSR bits */
  48 #define CTSR_PONM       BIT(8)
  49 #define CTSR_AOUT       BIT(7)
  50 #define CTSR_THBGR      BIT(5)
  51 #define CTSR_VMEN       BIT(4)
  52 #define CTSR_VMST       BIT(1)
  53 #define CTSR_THSST      BIT(0)
  54
  55 /* THCTR bits */
  56 #define THCTR_PONM      BIT(6)
  57 #define THCTR_THSST     BIT(0)
  58
  59 #define CTEMP_MASK      0xFFF
  60
  61 #define MCELSIUS(temp)  ((temp) * 1000)
  62 #define GEN3_FUSE_MASK  0xFFF
  63
  64 #define TSC_MAX_NUM     3
  65
  66 /* Structure for thermal temperature calculation */
  67 struct equation_coefs {
  68         int a1;
  69         int b1;
  70         int a2;
  71         int b2;
  72 };
  73
  74 struct rcar_gen3_thermal_tsc {
  75         void __iomem *base;
  76         struct thermal_zone_device *zone;
  77         struct equation_coefs coef;
  78         int low;
  79         int high;
  80 };
  81
  82 struct rcar_gen3_thermal_priv {
  83         struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
  84         unsigned int num_tscs;
  85         spinlock_t lock; /* Protect interrupts on and off */
  86         void (*thermal_init)(struct rcar_gen3_thermal_tsc *tsc);
  87 };
  88
  89 static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
  90                                          u32 reg)
  91 {
  92         return ioread32(tsc->base + reg);
  93 }
  94
  95 static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc,
  96                                            u32 reg, u32 data)
  97 {
  98         iowrite32(data, tsc->base + reg);
  99 }
 100
 101 /*
 102  * Linear approximation for temperature
 103  *
 104  * [reg] = [temp] * a + b => [temp] = ([reg] - b) / a
 105  *
 106  * The constants a and b are calculated using two triplets of int values PTAT
 107  * and THCODE. PTAT and THCODE can either be read from hardware or use hard
 108  * coded values from driver. The formula to calculate a and b are taken from
 109  * BSP and sparsely documented and understood.
 110  *
 111  * Examining the linear formula and the formula used to calculate constants a
 112  * and b while knowing that the span for PTAT and THCODE values are between
 113  * 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001.
 114  * Integer also needs to be signed so that leaves 7 bits for binary
 115  * fixed point scaling.
 116  */
 117
 118 #define FIXPT_SHIFT 7
 119 #define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT)
 120 #define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT)
 121 #define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b))
 122 #define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT)
 123
 124 #define RCAR3_THERMAL_GRAN 500 /* mili Celsius */
 125
 126 /* no idea where these constants come from */
 127 #define TJ_1 116
 128 #define TJ_3 -41
 129
 130 static void rcar_gen3_thermal_calc_coefs(struct equation_coefs *coef,
 131                                          int *ptat, int *thcode)
 132 {
 133         int tj_2;
 134
 135         /* TODO: Find documentation and document constant calculation formula */
 136
 137         /*
 138          * Division is not scaled in BSP and if scaled it might overflow
 139          * the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled
 140          */
 141         tj_2 = (FIXPT_INT((ptat[1] - ptat[2]) * 157)
 142                 / (ptat[0] - ptat[2])) - FIXPT_INT(41);
 143
 144         coef->a1 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[2]),
 145                              tj_2 - FIXPT_INT(TJ_3));
 146         coef->b1 = FIXPT_INT(thcode[2]) - coef->a1 * TJ_3;
 147
 148         coef->a2 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[0]),
 149                              tj_2 - FIXPT_INT(TJ_1));
 150         coef->b2 = FIXPT_INT(thcode[0]) - coef->a2 * TJ_1;
 151 }
 152
 153 static int rcar_gen3_thermal_round(int temp)
 154 {
 155         int result, round_offs;
 156
 157         round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 :
 158                 -RCAR3_THERMAL_GRAN / 2;
 159         result = (temp + round_offs) / RCAR3_THERMAL_GRAN;
 160         return result * RCAR3_THERMAL_GRAN;
 161 }
 162
 163 static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
 164 {
 165         struct rcar_gen3_thermal_tsc *tsc = devdata;
 166         int mcelsius, val1, val2;
 167         u32 reg;
 168
 169         /* Read register and convert to mili Celsius */
 170         reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;
 171
 172         val1 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1, tsc->coef.a1);
 173         val2 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2, tsc->coef.a2);
 174         mcelsius = FIXPT_TO_MCELSIUS((val1 + val2) / 2);
 175
 176         /* Make sure we are inside specifications */
 177         if ((mcelsius < MCELSIUS(-40)) || (mcelsius > MCELSIUS(125)))
 178                 return -EIO;
 179
 180         /* Round value to device granularity setting */
 181         *temp = rcar_gen3_thermal_round(mcelsius);
 182
 183         return 0;
 184 }
 185
 186 static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
 187                                               int mcelsius)
 188 {
 189         int celsius, val1, val2;
 190
 191         celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
 192         val1 = celsius * tsc->coef.a1 + tsc->coef.b1;
 193         val2 = celsius * tsc->coef.a2 + tsc->coef.b2;
 194
 195         return INT_FIXPT((val1 + val2) / 2);
 196 }
 197
 198 static int rcar_gen3_thermal_set_trips(void *devdata, int low, int high)
 199 {
 200         struct rcar_gen3_thermal_tsc *tsc = devdata;
 201
 202         low = clamp_val(low, -40000, 120000);
 203         high = clamp_val(high, -40000, 120000);
 204
 205         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
 206                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
 207
 208         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
 209                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
 210
 211         tsc->low = low;
 212         tsc->high = high;
 213
 214         return 0;
 215 }
 216
 217 static const struct thermal_zone_of_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 void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
 223 {
 224         unsigned int i;
 225         u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;
 226
 227         for (i = 0; i < priv->num_tscs; i++)
 228                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
 229 }
 230
 231 static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
 232 {
 233         struct rcar_gen3_thermal_priv *priv = data;
 234         u32 status;
 235         int i, ret = IRQ_HANDLED;
 236
 237         spin_lock(&priv->lock);
 238         for (i = 0; i < priv->num_tscs; i++) {
 239                 status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
 240                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
 241                 if (status)
 242                         ret = IRQ_WAKE_THREAD;
 243         }
 244
 245         if (ret == IRQ_WAKE_THREAD)
 246                 rcar_thermal_irq_set(priv, false);
 247
 248         spin_unlock(&priv->lock);
 249
 250         return ret;
 251 }
 252
 253 static irqreturn_t rcar_gen3_thermal_irq_thread(int irq, void *data)
 254 {
 255         struct rcar_gen3_thermal_priv *priv = data;
 256         unsigned long flags;
 257         int i;
 258
 259         for (i = 0; i < priv->num_tscs; i++)
 260                 thermal_zone_device_update(priv->tscs[i]->zone,
 261                                            THERMAL_EVENT_UNSPECIFIED);
 262
 263         spin_lock_irqsave(&priv->lock, flags);
 264         rcar_thermal_irq_set(priv, true);
 265         spin_unlock_irqrestore(&priv->lock, flags);
 266
 267         return IRQ_HANDLED;
 268 }
 269
 270 static const struct soc_device_attribute r8a7795es1[] = {
 271         { .soc_id = "r8a7795", .revision = "ES1.*" },
 272         { /* sentinel */ }
 273 };
 274
 275 static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
 276 {
 277         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  CTSR_THBGR);
 278         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  0x0);
 279
 280         usleep_range(1000, 2000);
 281
 282         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);
 283
 284         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 285         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 286         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 287
 288         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 289                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
 290
 291         usleep_range(100, 200);
 292
 293         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 294                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
 295                                 CTSR_VMST | CTSR_THSST);
 296
 297         usleep_range(1000, 2000);
 298 }
 299
 300 static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
 301 {
 302         u32 reg_val;
 303
 304         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 305         reg_val &= ~THCTR_PONM;
 306         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 307
 308         usleep_range(1000, 2000);
 309
 310         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 311         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 312         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, 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 struct of_device_id rcar_gen3_thermal_dt_ids[] = {
 322         { .compatible = "renesas,r8a774a1-thermal", },
 323         { .compatible = "renesas,r8a7795-thermal", },
 324         { .compatible = "renesas,r8a7796-thermal", },
 325         { .compatible = "renesas,r8a77965-thermal", },
 326         { .compatible = "renesas,r8a77980-thermal", },
 327         {},
 328 };
 329 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
 330
 331 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
 332 {
 333         struct device *dev = &pdev->dev;
 334
 335         pm_runtime_put(dev);
 336         pm_runtime_disable(dev);
 337
 338         return 0;
 339 }
 340
 341 static void rcar_gen3_hwmon_action(void *data)
 342 {
 343         struct thermal_zone_device *zone = data;
 344
 345         thermal_remove_hwmon_sysfs(zone);
 346 }
 347
 348 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 349 {
 350         struct rcar_gen3_thermal_priv *priv;
 351         struct device *dev = &pdev->dev;
 352         struct resource *res;
 353         struct thermal_zone_device *zone;
 354         int ret, irq, i;
 355         char *irqname;
 356
 357         /* default values if FUSEs are missing */
 358         /* TODO: Read values from hardware on supported platforms */
 359         int ptat[3] = { 2631, 1509, 435 };
 360         int thcode[TSC_MAX_NUM][3] = {
 361                 { 3397, 2800, 2221 },
 362                 { 3393, 2795, 2216 },
 363                 { 3389, 2805, 2237 },
 364         };
 365
 366         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 367         if (!priv)
 368                 return -ENOMEM;
 369
 370         priv->thermal_init = rcar_gen3_thermal_init;
 371         if (soc_device_match(r8a7795es1))
 372                 priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
 373
 374         spin_lock_init(&priv->lock);
 375
 376         platform_set_drvdata(pdev, priv);
 377
 378         /*
 379          * Request 2 (of the 3 possible) IRQs, the driver only needs to
 380          * to trigger on the low and high trip points of the current
 381          * temp window at this point.
 382          */
 383         for (i = 0; i < 2; i++) {
 384                 irq = platform_get_irq(pdev, i);
 385                 if (irq < 0)
 386                         return irq;
 387
 388                 irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
 389                                          dev_name(dev), i);
 390                 if (!irqname)
 391                         return -ENOMEM;
 392
 393                 ret = devm_request_threaded_irq(dev, irq, rcar_gen3_thermal_irq,
 394                                                 rcar_gen3_thermal_irq_thread,
 395                                                 IRQF_SHARED, irqname, priv);
 396                 if (ret)
 397                         return ret;
 398         }
 399
 400         pm_runtime_enable(dev);
 401         pm_runtime_get_sync(dev);
 402
 403         for (i = 0; i < TSC_MAX_NUM; i++) {
 404                 struct rcar_gen3_thermal_tsc *tsc;
 405
 406                 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 407                 if (!res)
 408                         break;
 409
 410                 tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
 411                 if (!tsc) {
 412                         ret = -ENOMEM;
 413                         goto error_unregister;
 414                 }
 415
 416                 tsc->base = devm_ioremap_resource(dev, res);
 417                 if (IS_ERR(tsc->base)) {
 418                         ret = PTR_ERR(tsc->base);
 419                         goto error_unregister;
 420                 }
 421
 422                 priv->tscs[i] = tsc;
 423
 424                 priv->thermal_init(tsc);
 425                 rcar_gen3_thermal_calc_coefs(&tsc->coef, ptat, thcode[i]);
 426
 427                 zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
 428                                                             &rcar_gen3_tz_of_ops);
 429                 if (IS_ERR(zone)) {
 430                         dev_err(dev, "Can't register thermal zone\n");
 431                         ret = PTR_ERR(zone);
 432                         goto error_unregister;
 433                 }
 434                 tsc->zone = zone;
 435
 436                 ret = of_thermal_get_ntrips(tsc->zone);
 437                 if (ret < 0)
 438                         goto error_unregister;
 439
 440                 tsc->zone->tzp->no_hwmon = false;
 441                 ret = thermal_add_hwmon_sysfs(tsc->zone);
 442                 if (ret)
 443                         goto error_unregister;
 444
 445                 ret = devm_add_action(dev, rcar_gen3_hwmon_action, zone);
 446                 if (ret) {
 447                         rcar_gen3_hwmon_action(zone);
 448                         goto error_unregister;
 449                 }
 450
 451                 dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
 452         }
 453
 454         priv->num_tscs = i;
 455
 456         if (!priv->num_tscs) {
 457                 ret = -ENODEV;
 458                 goto error_unregister;
 459         }
 460
 461         rcar_thermal_irq_set(priv, true);
 462
 463         return 0;
 464
 465 error_unregister:
 466         rcar_gen3_thermal_remove(pdev);
 467
 468         return ret;
 469 }
 470
 471 static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
 472 {
 473         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 474
 475         rcar_thermal_irq_set(priv, false);
 476
 477         return 0;
 478 }
 479
 480 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 481 {
 482         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 483         unsigned int i;
 484
 485         for (i = 0; i < priv->num_tscs; i++) {
 486                 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 487
 488                 priv->thermal_init(tsc);
 489                 rcar_gen3_thermal_set_trips(tsc, tsc->low, tsc->high);
 490         }
 491
 492         rcar_thermal_irq_set(priv, true);
 493
 494         return 0;
 495 }
 496
 497 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
 498                          rcar_gen3_thermal_resume);
 499
 500 static struct platform_driver rcar_gen3_thermal_driver = {
 501         .driver = {
 502                 .name   = "rcar_gen3_thermal",
 503                 .pm = &rcar_gen3_thermal_pm_ops,
 504                 .of_match_table = rcar_gen3_thermal_dt_ids,
 505         },
 506         .probe          = rcar_gen3_thermal_probe,
 507         .remove         = rcar_gen3_thermal_remove,
 508 };
 509 module_platform_driver(rcar_gen3_thermal_driver);
 510
 511 MODULE_LICENSE("GPL v2");
 512 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
 513 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");