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
  22 /* Register offsets */
  23 #define REG_GEN3_IRQSTR         0x04
  24 #define REG_GEN3_IRQMSK         0x08
  25 #define REG_GEN3_IRQCTL         0x0C
  26 #define REG_GEN3_IRQEN          0x10
  27 #define REG_GEN3_IRQTEMP1       0x14
  28 #define REG_GEN3_IRQTEMP2       0x18
  29 #define REG_GEN3_IRQTEMP3       0x1C
  30 #define REG_GEN3_CTSR           0x20
  31 #define REG_GEN3_THCTR          0x20
  32 #define REG_GEN3_TEMP           0x28
  33 #define REG_GEN3_THCODE1        0x50
  34 #define REG_GEN3_THCODE2        0x54
  35 #define REG_GEN3_THCODE3        0x58
  36
  37 /* IRQ{STR,MSK,EN} bits */
  38 #define IRQ_TEMP1               BIT(0)
  39 #define IRQ_TEMP2               BIT(1)
  40 #define IRQ_TEMP3               BIT(2)
  41 #define IRQ_TEMPD1              BIT(3)
  42 #define IRQ_TEMPD2              BIT(4)
  43 #define IRQ_TEMPD3              BIT(5)
  44
  45 /* CTSR bits */
  46 #define CTSR_PONM       BIT(8)
  47 #define CTSR_AOUT       BIT(7)
  48 #define CTSR_THBGR      BIT(5)
  49 #define CTSR_VMEN       BIT(4)
  50 #define CTSR_VMST       BIT(1)
  51 #define CTSR_THSST      BIT(0)
  52
  53 /* THCTR bits */
  54 #define THCTR_PONM      BIT(6)
  55 #define THCTR_THSST     BIT(0)
  56
  57 #define CTEMP_MASK      0xFFF
  58
  59 #define MCELSIUS(temp)  ((temp) * 1000)
  60 #define GEN3_FUSE_MASK  0xFFF
  61
  62 #define TSC_MAX_NUM     3
  63
  64 /* Structure for thermal temperature calculation */
  65 struct equation_coefs {
  66         int a1;
  67         int b1;
  68         int a2;
  69         int b2;
  70 };
  71
  72 struct rcar_gen3_thermal_tsc {
  73         void __iomem *base;
  74         struct thermal_zone_device *zone;
  75         struct equation_coefs coef;
  76         int low;
  77         int high;
  78 };
  79
  80 struct rcar_gen3_thermal_priv {
  81         struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
  82         unsigned int num_tscs;
  83         void (*thermal_init)(struct rcar_gen3_thermal_tsc *tsc);
  84 };
  85
  86 static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
  87                                          u32 reg)
  88 {
  89         return ioread32(tsc->base + reg);
  90 }
  91
  92 static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc,
  93                                            u32 reg, u32 data)
  94 {
  95         iowrite32(data, tsc->base + reg);
  96 }
  97
  98 /*
  99  * Linear approximation for temperature
 100  *
 101  * [reg] = [temp] * a + b => [temp] = ([reg] - b) / a
 102  *
 103  * The constants a and b are calculated using two triplets of int values PTAT
 104  * and THCODE. PTAT and THCODE can either be read from hardware or use hard
 105  * coded values from driver. The formula to calculate a and b are taken from
 106  * BSP and sparsely documented and understood.
 107  *
 108  * Examining the linear formula and the formula used to calculate constants a
 109  * and b while knowing that the span for PTAT and THCODE values are between
 110  * 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001.
 111  * Integer also needs to be signed so that leaves 7 bits for binary
 112  * fixed point scaling.
 113  */
 114
 115 #define FIXPT_SHIFT 7
 116 #define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT)
 117 #define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT)
 118 #define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b))
 119 #define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT)
 120
 121 #define RCAR3_THERMAL_GRAN 500 /* mili Celsius */
 122
 123 /* no idea where these constants come from */
 124 #define TJ_1 116
 125 #define TJ_3 -41
 126
 127 static void rcar_gen3_thermal_calc_coefs(struct equation_coefs *coef,
 128                                          int *ptat, int *thcode)
 129 {
 130         int tj_2;
 131
 132         /* TODO: Find documentation and document constant calculation formula */
 133
 134         /*
 135          * Division is not scaled in BSP and if scaled it might overflow
 136          * the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled
 137          */
 138         tj_2 = (FIXPT_INT((ptat[1] - ptat[2]) * 157)
 139                 / (ptat[0] - ptat[2])) - FIXPT_INT(41);
 140
 141         coef->a1 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[2]),
 142                              tj_2 - FIXPT_INT(TJ_3));
 143         coef->b1 = FIXPT_INT(thcode[2]) - coef->a1 * TJ_3;
 144
 145         coef->a2 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[0]),
 146                              tj_2 - FIXPT_INT(TJ_1));
 147         coef->b2 = FIXPT_INT(thcode[0]) - coef->a2 * TJ_1;
 148 }
 149
 150 static int rcar_gen3_thermal_round(int temp)
 151 {
 152         int result, round_offs;
 153
 154         round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 :
 155                 -RCAR3_THERMAL_GRAN / 2;
 156         result = (temp + round_offs) / RCAR3_THERMAL_GRAN;
 157         return result * RCAR3_THERMAL_GRAN;
 158 }
 159
 160 static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
 161 {
 162         struct rcar_gen3_thermal_tsc *tsc = devdata;
 163         int mcelsius, val1, val2;
 164         u32 reg;
 165
 166         /* Read register and convert to mili Celsius */
 167         reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;
 168
 169         val1 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1, tsc->coef.a1);
 170         val2 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2, tsc->coef.a2);
 171         mcelsius = FIXPT_TO_MCELSIUS((val1 + val2) / 2);
 172
 173         /* Make sure we are inside specifications */
 174         if ((mcelsius < MCELSIUS(-40)) || (mcelsius > MCELSIUS(125)))
 175                 return -EIO;
 176
 177         /* Round value to device granularity setting */
 178         *temp = rcar_gen3_thermal_round(mcelsius);
 179
 180         return 0;
 181 }
 182
 183 static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
 184                                               int mcelsius)
 185 {
 186         int celsius, val1, val2;
 187
 188         celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
 189         val1 = celsius * tsc->coef.a1 + tsc->coef.b1;
 190         val2 = celsius * tsc->coef.a2 + tsc->coef.b2;
 191
 192         return INT_FIXPT((val1 + val2) / 2);
 193 }
 194
 195 static int rcar_gen3_thermal_set_trips(void *devdata, int low, int high)
 196 {
 197         struct rcar_gen3_thermal_tsc *tsc = devdata;
 198
 199         low = clamp_val(low, -40000, 120000);
 200         high = clamp_val(high, -40000, 120000);
 201
 202         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
 203                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
 204
 205         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
 206                                 rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
 207
 208         tsc->low = low;
 209         tsc->high = high;
 210
 211         return 0;
 212 }
 213
 214 static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
 215         .get_temp       = rcar_gen3_thermal_get_temp,
 216         .set_trips      = rcar_gen3_thermal_set_trips,
 217 };
 218
 219 static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
 220 {
 221         unsigned int i;
 222         u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;
 223
 224         for (i = 0; i < priv->num_tscs; i++)
 225                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
 226 }
 227
 228 static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
 229 {
 230         struct rcar_gen3_thermal_priv *priv = data;
 231         u32 status;
 232         int i;
 233
 234         for (i = 0; i < priv->num_tscs; i++) {
 235                 status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
 236                 rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
 237                 if (status)
 238                         thermal_zone_device_update(priv->tscs[i]->zone,
 239                                                    THERMAL_EVENT_UNSPECIFIED);
 240         }
 241
 242         return IRQ_HANDLED;
 243 }
 244
 245 static const struct soc_device_attribute r8a7795es1[] = {
 246         { .soc_id = "r8a7795", .revision = "ES1.*" },
 247         { /* sentinel */ }
 248 };
 249
 250 static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
 251 {
 252         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  CTSR_THBGR);
 253         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  0x0);
 254
 255         usleep_range(1000, 2000);
 256
 257         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);
 258
 259         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 260         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 261         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 262
 263         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 264                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
 265
 266         usleep_range(100, 200);
 267
 268         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 269                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
 270                                 CTSR_VMST | CTSR_THSST);
 271
 272         usleep_range(1000, 2000);
 273 }
 274
 275 static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
 276 {
 277         u32 reg_val;
 278
 279         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 280         reg_val &= ~THCTR_PONM;
 281         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 282
 283         usleep_range(1000, 2000);
 284
 285         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 286         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 287         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 288
 289         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 290         reg_val |= THCTR_THSST;
 291         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 292
 293         usleep_range(1000, 2000);
 294 }
 295
 296 static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
 297         { .compatible = "renesas,r8a7795-thermal", },
 298         { .compatible = "renesas,r8a7796-thermal", },
 299         { .compatible = "renesas,r8a77965-thermal", },
 300         {},
 301 };
 302 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
 303
 304 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
 305 {
 306         struct device *dev = &pdev->dev;
 307         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 308
 309         rcar_thermal_irq_set(priv, false);
 310
 311         pm_runtime_put(dev);
 312         pm_runtime_disable(dev);
 313
 314         return 0;
 315 }
 316
 317 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 318 {
 319         struct rcar_gen3_thermal_priv *priv;
 320         struct device *dev = &pdev->dev;
 321         struct resource *res;
 322         struct thermal_zone_device *zone;
 323         int ret, irq, i;
 324         char *irqname;
 325
 326         /* default values if FUSEs are missing */
 327         /* TODO: Read values from hardware on supported platforms */
 328         int ptat[3] = { 2631, 1509, 435 };
 329         int thcode[TSC_MAX_NUM][3] = {
 330                 { 3397, 2800, 2221 },
 331                 { 3393, 2795, 2216 },
 332                 { 3389, 2805, 2237 },
 333         };
 334
 335         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 336         if (!priv)
 337                 return -ENOMEM;
 338
 339         priv->thermal_init = rcar_gen3_thermal_init;
 340         if (soc_device_match(r8a7795es1))
 341                 priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
 342
 343         platform_set_drvdata(pdev, priv);
 344
 345         /*
 346          * Request 2 (of the 3 possible) IRQs, the driver only needs to
 347          * to trigger on the low and high trip points of the current
 348          * temp window at this point.
 349          */
 350         for (i = 0; i < 2; i++) {
 351                 irq = platform_get_irq(pdev, i);
 352                 if (irq < 0)
 353                         return irq;
 354
 355                 irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
 356                                          dev_name(dev), i);
 357                 if (!irqname)
 358                         return -ENOMEM;
 359
 360                 ret = devm_request_threaded_irq(dev, irq, NULL,
 361                                                 rcar_gen3_thermal_irq,
 362                                                 IRQF_ONESHOT, irqname, priv);
 363                 if (ret)
 364                         return ret;
 365         }
 366
 367         pm_runtime_enable(dev);
 368         pm_runtime_get_sync(dev);
 369
 370         for (i = 0; i < TSC_MAX_NUM; i++) {
 371                 struct rcar_gen3_thermal_tsc *tsc;
 372
 373                 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 374                 if (!res)
 375                         break;
 376
 377                 tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
 378                 if (!tsc) {
 379                         ret = -ENOMEM;
 380                         goto error_unregister;
 381                 }
 382
 383                 tsc->base = devm_ioremap_resource(dev, res);
 384                 if (IS_ERR(tsc->base)) {
 385                         ret = PTR_ERR(tsc->base);
 386                         goto error_unregister;
 387                 }
 388
 389                 priv->tscs[i] = tsc;
 390
 391                 priv->thermal_init(tsc);
 392                 rcar_gen3_thermal_calc_coefs(&tsc->coef, ptat, thcode[i]);
 393
 394                 zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
 395                                                             &rcar_gen3_tz_of_ops);
 396                 if (IS_ERR(zone)) {
 397                         dev_err(dev, "Can't register thermal zone\n");
 398                         ret = PTR_ERR(zone);
 399                         goto error_unregister;
 400                 }
 401                 tsc->zone = zone;
 402
 403                 ret = of_thermal_get_ntrips(tsc->zone);
 404                 if (ret < 0)
 405                         goto error_unregister;
 406
 407                 dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
 408         }
 409
 410         priv->num_tscs = i;
 411
 412         if (!priv->num_tscs) {
 413                 ret = -ENODEV;
 414                 goto error_unregister;
 415         }
 416
 417         rcar_thermal_irq_set(priv, true);
 418
 419         return 0;
 420
 421 error_unregister:
 422         rcar_gen3_thermal_remove(pdev);
 423
 424         return ret;
 425 }
 426
 427 static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
 428 {
 429         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 430
 431         rcar_thermal_irq_set(priv, false);
 432
 433         return 0;
 434 }
 435
 436 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 437 {
 438         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 439         unsigned int i;
 440
 441         for (i = 0; i < priv->num_tscs; i++) {
 442                 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 443
 444                 priv->thermal_init(tsc);
 445                 rcar_gen3_thermal_set_trips(tsc, tsc->low, tsc->high);
 446         }
 447
 448         rcar_thermal_irq_set(priv, true);
 449
 450         return 0;
 451 }
 452
 453 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
 454                          rcar_gen3_thermal_resume);
 455
 456 static struct platform_driver rcar_gen3_thermal_driver = {
 457         .driver = {
 458                 .name   = "rcar_gen3_thermal",
 459                 .pm = &rcar_gen3_thermal_pm_ops,
 460                 .of_match_table = rcar_gen3_thermal_dt_ids,
 461         },
 462         .probe          = rcar_gen3_thermal_probe,
 463         .remove         = rcar_gen3_thermal_remove,
 464 };
 465 module_platform_driver(rcar_gen3_thermal_driver);
 466
 467 MODULE_LICENSE("GPL v2");
 468 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
 469 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");