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         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         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 const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
 194         .get_temp       = rcar_gen3_thermal_get_temp,
 195 };
 196
 197 static const struct soc_device_attribute r8a7795es1[] = {
 198         { .soc_id = "r8a7795", .revision = "ES1.*" },
 199         { /* sentinel */ }
 200 };
 201
 202 static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
 203 {
 204         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  CTSR_THBGR);
 205         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  0x0);
 206
 207         usleep_range(1000, 2000);
 208
 209         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);
 210
 211         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 212         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 213
 214         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 215                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
 216
 217         usleep_range(100, 200);
 218
 219         rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 220                                 CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
 221                                 CTSR_VMST | CTSR_THSST);
 222
 223         usleep_range(1000, 2000);
 224 }
 225
 226 static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
 227 {
 228         u32 reg_val;
 229
 230         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 231         reg_val &= ~THCTR_PONM;
 232         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 233
 234         usleep_range(1000, 2000);
 235
 236         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
 237         rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 238
 239         reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 240         reg_val |= THCTR_THSST;
 241         rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
 242
 243         usleep_range(1000, 2000);
 244 }
 245
 246 static const int rcar_gen3_ths_tj_1 = 126;
 247 static const int rcar_gen3_ths_tj_1_m3_w = 116;
 248 static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
 249         {
 250                 .compatible = "renesas,r8a774a1-thermal",
 251                 .data = &rcar_gen3_ths_tj_1_m3_w,
 252         },
 253         {
 254                 .compatible = "renesas,r8a774b1-thermal",
 255                 .data = &rcar_gen3_ths_tj_1,
 256         },
 257         {
 258                 .compatible = "renesas,r8a774e1-thermal",
 259                 .data = &rcar_gen3_ths_tj_1,
 260         },
 261         {
 262                 .compatible = "renesas,r8a7795-thermal",
 263                 .data = &rcar_gen3_ths_tj_1,
 264         },
 265         {
 266                 .compatible = "renesas,r8a7796-thermal",
 267                 .data = &rcar_gen3_ths_tj_1_m3_w,
 268         },
 269         {
 270                 .compatible = "renesas,r8a77961-thermal",
 271                 .data = &rcar_gen3_ths_tj_1_m3_w,
 272         },
 273         {
 274                 .compatible = "renesas,r8a77965-thermal",
 275                 .data = &rcar_gen3_ths_tj_1,
 276         },
 277         {
 278                 .compatible = "renesas,r8a77980-thermal",
 279                 .data = &rcar_gen3_ths_tj_1,
 280         },
 281         {
 282                 .compatible = "renesas,r8a779a0-thermal",
 283                 .data = &rcar_gen3_ths_tj_1,
 284         },
 285         {},
 286 };
 287 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
 288
 289 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
 290 {
 291         struct device *dev = &pdev->dev;
 292
 293         pm_runtime_put(dev);
 294         pm_runtime_disable(dev);
 295
 296         return 0;
 297 }
 298
 299 static void rcar_gen3_hwmon_action(void *data)
 300 {
 301         struct thermal_zone_device *zone = data;
 302
 303         thermal_remove_hwmon_sysfs(zone);
 304 }
 305
 306 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 307 {
 308         struct rcar_gen3_thermal_priv *priv;
 309         struct device *dev = &pdev->dev;
 310         const int *rcar_gen3_ths_tj_1 = of_device_get_match_data(dev);
 311         struct resource *res;
 312         struct thermal_zone_device *zone;
 313         int ret, i;
 314
 315         /* default values if FUSEs are missing */
 316         /* TODO: Read values from hardware on supported platforms */
 317         int ptat[3] = { 2631, 1509, 435 };
 318
 319         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 320         if (!priv)
 321                 return -ENOMEM;
 322
 323         priv->thermal_init = rcar_gen3_thermal_init;
 324         if (soc_device_match(r8a7795es1))
 325                 priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
 326
 327         platform_set_drvdata(pdev, priv);
 328
 329         pm_runtime_enable(dev);
 330         pm_runtime_get_sync(dev);
 331
 332         for (i = 0; i < TSC_MAX_NUM; i++) {
 333                 struct rcar_gen3_thermal_tsc *tsc;
 334
 335                 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 336                 if (!res)
 337                         break;
 338
 339                 tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
 340                 if (!tsc) {
 341                         ret = -ENOMEM;
 342                         goto error_unregister;
 343                 }
 344
 345                 tsc->base = devm_ioremap_resource(dev, res);
 346                 if (IS_ERR(tsc->base)) {
 347                         ret = PTR_ERR(tsc->base);
 348                         goto error_unregister;
 349                 }
 350                 tsc->id = i;
 351
 352                 priv->tscs[i] = tsc;
 353
 354                 priv->thermal_init(tsc);
 355                 rcar_gen3_thermal_calc_coefs(tsc, ptat, thcodes[i],
 356                                              *rcar_gen3_ths_tj_1);
 357
 358                 zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
 359                                                             &rcar_gen3_tz_of_ops);
 360                 if (IS_ERR(zone)) {
 361                         dev_err(dev, "Can't register thermal zone\n");
 362                         ret = PTR_ERR(zone);
 363                         goto error_unregister;
 364                 }
 365                 tsc->zone = zone;
 366
 367                 tsc->zone->tzp->no_hwmon = false;
 368                 ret = thermal_add_hwmon_sysfs(tsc->zone);
 369                 if (ret)
 370                         goto error_unregister;
 371
 372                 ret = devm_add_action_or_reset(dev, rcar_gen3_hwmon_action, zone);
 373                 if (ret)
 374                         goto error_unregister;
 375
 376                 ret = of_thermal_get_ntrips(tsc->zone);
 377                 if (ret < 0)
 378                         goto error_unregister;
 379
 380                 dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
 381         }
 382
 383         priv->num_tscs = i;
 384
 385         if (!priv->num_tscs) {
 386                 ret = -ENODEV;
 387                 goto error_unregister;
 388         }
 389
 390         return 0;
 391
 392 error_unregister:
 393         rcar_gen3_thermal_remove(pdev);
 394
 395         return ret;
 396 }
 397
 398 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 399 {
 400         struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 401         unsigned int i;
 402
 403         for (i = 0; i < priv->num_tscs; i++) {
 404                 struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 405
 406                 priv->thermal_init(tsc);
 407         }
 408
 409         return 0;
 410 }
 411
 412 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, NULL,
 413                          rcar_gen3_thermal_resume);
 414
 415 static struct platform_driver rcar_gen3_thermal_driver = {
 416         .driver = {
 417                 .name   = "rcar_gen3_thermal",
 418                 .pm = &rcar_gen3_thermal_pm_ops,
 419                 .of_match_table = rcar_gen3_thermal_dt_ids,
 420         },
 421         .probe          = rcar_gen3_thermal_probe,
 422         .remove         = rcar_gen3_thermal_remove,
 423 };
 424 module_platform_driver(rcar_gen3_thermal_driver);
 425
 426 MODULE_LICENSE("GPL v2");
 427 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
 428 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");