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
  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 /* Structure for thermal temperature calculation */
  66 struct equation_coefs {
  67         int a1;
  68         int b1;
  69         int a2;
  70         int b2;
  71 };
  72
  73 struct rcar_gen3_thermal_tsc {
  74         void __iomem *base;
  75         struct thermal_zone_device *zone;
  76         struct equation_coefs coef;
  77         int low;
  78         int high;
  79 };
  80
  81 struct rcar_gen3_thermal_priv {
  82         struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
  83         unsigned int num_tscs;
  84         spinlock_t lock; /* Protect interrupts on and off */
  85         void (*thermal_init)(struct rcar_gen3_thermal_tsc *tsc);
  86 };
  87
  88 static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
  89                                          u32 reg)
  90 {
  91         return ioread32(tsc->base + reg);
  92 }
  93
  94 static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc,
  95                                            u32 reg, u32 data)
  96 {
  97         iowrite32(data, tsc->base + reg);
  98 }
  99
 100 /*
 101  * Linear approximation for temperature
 102  *
 103  * [reg] = [temp] * a + b => [temp] = ([reg] - b) / a
 104  *
 105  * The constants a and b are calculated using two triplets of int values PTAT
 106  * and THCODE. PTAT and THCODE can either be read from hardware or use hard
 107  * coded values from driver. The formula to calculate a and b are taken from
 108  * BSP and sparsely documented and understood.
 109  *
 110  * Examining the linear formula and the formula used to calculate constants a
 111  * and b while knowing that the span for PTAT and THCODE values are between
 112  * 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001.
 113  * Integer also needs to be signed so that leaves 7 bits for binary
 114  * fixed point scaling.
 115  */
 116
 117 #define FIXPT_SHIFT 7
 118 #define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT)
 119 #define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT)
 120 #define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b))
 121 #define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT)
 122
 123 #define RCAR3_THERMAL_GRAN 500 /* mili Celsius */
 124
 125 /* no idea where these constants come from */
 126 #define TJ_1 116
 127 #define TJ_3 -41
 128
 129 static void rcar_gen3_thermal_calc_coefs(struct equation_coefs *coef,
 130                                          int *ptat, int *thcode)
 131 {
 132         int tj_2;
 133
 134         /* TODO: Find documentation and document constant calculation formula */
 135
 136         /*
 137          * Division is not scaled in BSP and if scaled it might overflow
 138          * the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled
 139          */
 140         tj_2 = (FIXPT_INT((ptat[1] - ptat[2]) * 157)
 141                 / (ptat[0] - ptat[2])) - FIXPT_INT(41);
 142
 143         coef->a1 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[2]),
 144                              tj_2 - FIXPT_INT(TJ_3));
 145         coef->b1 = FIXPT_INT(thcode[2]) - coef->a1 * TJ_3;
 146
 147         coef->a2 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[0]),
 148                              tj_2 - FIXPT_INT(TJ_1));
 149         coef->b2 = FIXPT_INT(thcode[0]) - coef->a2 * TJ_1;
 150 }
 151
 152 static int rcar_gen3_thermal_round(int temp)
 153 {
 154         int result, round_offs;
 155
 156         round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 :
 157                 -RCAR3_THERMAL_GRAN / 2;
 158         result = (temp + round_offs) / RCAR3_THERMAL_GRAN;
 159         return result * RCAR3_THERMAL_GRAN;
 160 }
 161
 162 static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
 163 {
 164         struct rcar_gen3_thermal_tsc *tsc = devdata;
 165         int mcelsius, val1, val2;
 166         u32 reg;
 167
 168         /* Read register and convert to mili Celsius */
 169         reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;
 170
 171         val1 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1, tsc->coef.a1);
 172         val2 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2, tsc->coef.a2);
 173         mcelsius = FIXPT_TO_MCELSIUS((val1 + val2) / 2);
 174
 175         /* Make sure we are inside specifications */
 176         if ((mcelsius < MCELSIUS(-40)) || (mcelsius > MCELSIUS(125)))
 177                 return -EIO;
 178
 179         /* Round value to device granularity setting */
 180         *temp = rcar_gen3_thermal_round(mcelsius);
 181
 182         return 0;
 183 }
 184
 185 static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
 186                                               int mcelsius)
 187 {
 188         int celsius, val1, val2;
 189
 190         celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
 191         val1 = celsius * tsc->coef.a1 + tsc->coef.b1;
 192         val2 = celsius * tsc->coef.a2 + tsc->coef.b2;
 193
 194         return INT_FIXPT((val1 + val2) / 2);
 195 }
 196
 197 static int rcar_gen3_thermal_set_trips(void *devdata, int low, int high)
 198 {
 199         struct rcar_gen3_thermal_tsc *tsc = devdata;
 200
 201         low = clamp_val(low, -40000, 120000);
 202         high = clamp_val(high, -40000, 120000);
 203
 204         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
 205                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
 206
 207         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
 208                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
 209
 210         tsc->low = low;
 211         tsc->high = high;
 212
 213         return 0;
 214 }
 215
 216 static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
 217         .get_temp       = rcar_gen3_thermal_get_temp,
 218         .set_trips      = rcar_gen3_thermal_set_trips,
 219 };
 220
 221 static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
 222 {
 223         unsigned int i;
 224         u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;
 225
 226         for (i = 0; i < priv->num_tscs; i++)
 227                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
 228 }
 229
 230 static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
 231 {
 232         struct rcar_gen3_thermal_priv *priv = data;
 233         u32 status;
 234         int i, ret = IRQ_HANDLED;
 235
 236         spin_lock(&priv->lock);
 237         for (i = 0; i < priv->num_tscs; i++) {
 238                 status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
 239                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
 240                 if (status)
 241                         ret = IRQ_WAKE_THREAD;
 242         }
 243
 244         if (ret == IRQ_WAKE_THREAD)
 245                 rcar_thermal_irq_set(priv, false);
 246
 247         spin_unlock(&priv->lock);
 248
 249         return ret;
 250 }
 251
 252 static irqreturn_t rcar_gen3_thermal_irq_thread(int irq, void *data)
 253 {
 254         struct rcar_gen3_thermal_priv *priv = data;
 255         unsigned long flags;
 256         int i;
 257
 258         for (i = 0; i < priv->num_tscs; i++)
 259                 thermal_zone_device_update(priv->tscs[i]->zone,
 260                                            THERMAL_EVENT_UNSPECIFIED);
 261
 262         spin_lock_irqsave(&priv->lock, flags);
 263         rcar_thermal_irq_set(priv, true);
 264         spin_unlock_irqrestore(&priv->lock, flags);
 265
 266         return IRQ_HANDLED;
 267 }
 268
 269 static const struct soc_device_attribute r8a7795es1[] = {
 270         { .soc_id = "r8a7795", .revision = "ES1.*" },
 271         { /* sentinel */ }
 272 };
 273
 274 static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
 275 {
 276         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  CTSR_THBGR);
 277         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  0x0);
 278
 279         usleep_range(1000, 2000);
 280
 281         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);
 282
 283         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 284         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 285         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 286
 287         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 288                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
 289
 290         usleep_range(100, 200);
 291
 292         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 293                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
 294                                 CTSR_VMST | CTSR_THSST);
 295
 296         usleep_range(1000, 2000);
 297 }
 298
 299 static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
 300 {
 301         u32 reg_val;
 302
 303         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 304         reg_val &= ~THCTR_PONM;
 305         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 306
 307         usleep_range(1000, 2000);
 308
 309         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 310         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 311         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 312
 313         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 314         reg_val |= THCTR_THSST;
 315         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 316
 317         usleep_range(1000, 2000);
 318 }
 319
 320 static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
 321         { .compatible = "renesas,r8a7795-thermal", },
 322         { .compatible = "renesas,r8a7796-thermal", },
 323         { .compatible = "renesas,r8a77965-thermal", },
 324         {},
 325 };
 326 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
 327
 328 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
 329 {
 330         struct device *dev = &pdev->dev;
 331
 332         pm_runtime_put(dev);
 333         pm_runtime_disable(dev);
 334
 335         return 0;
 336 }
 337
 338 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 339 {
 340         struct rcar_gen3_thermal_priv *priv;
 341         struct device *dev = &pdev->dev;
 342         struct resource *res;
 343         struct thermal_zone_device *zone;
 344         int ret, irq, i;
 345         char *irqname;
 346
 347         /* default values if FUSEs are missing */
 348         /* TODO: Read values from hardware on supported platforms */
 349         int ptat[3] = { 2631, 1509, 435 };
 350         int thcode[TSC_MAX_NUM][3] = {
 351                 { 3397, 2800, 2221 },
 352                 { 3393, 2795, 2216 },
 353                 { 3389, 2805, 2237 },
 354         };
 355
 356         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 357         if (!priv)
 358                 return -ENOMEM;
 359
 360         priv->thermal_init = rcar_gen3_thermal_init;
 361         if (soc_device_match(r8a7795es1))
 362                 priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
 363
 364         spin_lock_init(&priv->lock);
 365
 366         platform_set_drvdata(pdev, priv);
 367
 368         /*
 369          * Request 2 (of the 3 possible) IRQs, the driver only needs to
 370          * to trigger on the low and high trip points of the current
 371          * temp window at this point.
 372          */
 373         for (i = 0; i < 2; i++) {
 374                 irq = platform_get_irq(pdev, i);
 375                 if (irq < 0)
 376                         return irq;
 377
 378                 irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
 379                                          dev_name(dev), i);
 380                 if (!irqname)
 381                         return -ENOMEM;
 382
 383                 ret = devm_request_threaded_irq(dev, irq, rcar_gen3_thermal_irq,
 384                                                 rcar_gen3_thermal_irq_thread,
 385                                                 IRQF_SHARED, irqname, priv);
 386                 if (ret)
 387                         return ret;
 388         }
 389
 390         pm_runtime_enable(dev);
 391         pm_runtime_get_sync(dev);
 392
 393         for (i = 0; i < TSC_MAX_NUM; i++) {
 394                 struct rcar_gen3_thermal_tsc *tsc;
 395
 396                 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 397                 if (!res)
 398                         break;
 399
 400                 tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
 401                 if (!tsc) {
 402                         ret = -ENOMEM;
 403                         goto error_unregister;
 404                 }
 405
 406                 tsc->base = devm_ioremap_resource(dev, res);
 407                 if (IS_ERR(tsc->base)) {
 408                         ret = PTR_ERR(tsc->base);
 409                         goto error_unregister;
 410                 }
 411
 412                 priv->tscs[i] = tsc;
 413
 414                 priv->thermal_init(tsc);
 415                 rcar_gen3_thermal_calc_coefs(&tsc->coef, ptat, thcode[i]);
 416
 417                 zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
 418                                                             &rcar_gen3_tz_of_ops);
 419                 if (IS_ERR(zone)) {
 420                         dev_err(dev, "Can't register thermal zone\n");
 421                         ret = PTR_ERR(zone);
 422                         goto error_unregister;
 423                 }
 424                 tsc->zone = zone;
 425
 426                 ret = of_thermal_get_ntrips(tsc->zone);
 427                 if (ret < 0)
 428                         goto error_unregister;
 429
 430                 dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
 431         }
 432
 433         priv->num_tscs = i;
 434
 435         if (!priv->num_tscs) {
 436                 ret = -ENODEV;
 437                 goto error_unregister;
 438         }
 439
 440         rcar_thermal_irq_set(priv, true);
 441
 442         return 0;
 443
 444 error_unregister:
 445         rcar_gen3_thermal_remove(pdev);
 446
 447         return ret;
 448 }
 449
 450 static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
 451 {
 452         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 453
 454         rcar_thermal_irq_set(priv, false);
 455
 456         return 0;
 457 }
 458
 459 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 460 {
 461         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 462         unsigned int i;
 463
 464         for (i = 0; i < priv->num_tscs; i++) {
 465                 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 466
 467                 priv->thermal_init(tsc);
 468                 rcar_gen3_thermal_set_trips(tsc, tsc->low, tsc->high);
 469         }
 470
 471         rcar_thermal_irq_set(priv, true);
 472
 473         return 0;
 474 }
 475
 476 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
 477                          rcar_gen3_thermal_resume);
 478
 479 static struct platform_driver rcar_gen3_thermal_driver = {
 480         .driver = {
 481                 .name   = "rcar_gen3_thermal",
 482                 .pm = &rcar_gen3_thermal_pm_ops,
 483                 .of_match_table = rcar_gen3_thermal_dt_ids,
 484         },
 485         .probe          = rcar_gen3_thermal_probe,
 486         .remove         = rcar_gen3_thermal_remove,
 487 };
 488 module_platform_driver(rcar_gen3_thermal_driver);
 489
 490 MODULE_LICENSE("GPL v2");
 491 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
 492 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");