linux/drivers/thermal/rcar_gen3_thermal.c
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   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 */
  66static 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 */
  75struct equation_coefs {
  76        int a1;
  77        int b1;
  78        int a2;
  79        int b2;
  80};
  81
  82struct 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
  90struct 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
  96static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
  97                                         u32 reg)
  98{
  99        return ioread32(tsc->base + reg);
 100}
 101
 102static 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
 136static 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]) * (ths_tj_1 - TJ_3))
 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
 158static 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
 168static 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
 193static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
 194        .get_temp       = rcar_gen3_thermal_get_temp,
 195};
 196
 197static const struct soc_device_attribute r8a7795es1[] = {
 198        { .soc_id = "r8a7795", .revision = "ES1.*" },
 199        { /* sentinel */ }
 200};
 201
 202static 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
 226static 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
 246static const int rcar_gen3_ths_tj_1 = 126;
 247static const int rcar_gen3_ths_tj_1_m3_w = 116;
 248static 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};
 287MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
 288
 289static 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
 299static void rcar_gen3_hwmon_action(void *data)
 300{
 301        struct thermal_zone_device *zone = data;
 302
 303        thermal_remove_hwmon_sysfs(zone);
 304}
 305
 306static 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 *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], *ths_tj_1);
 356
 357                zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
 358                                                            &rcar_gen3_tz_of_ops);
 359                if (IS_ERR(zone)) {
 360                        dev_err(dev, "Can't register thermal zone\n");
 361                        ret = PTR_ERR(zone);
 362                        goto error_unregister;
 363                }
 364                tsc->zone = zone;
 365
 366                tsc->zone->tzp->no_hwmon = false;
 367                ret = thermal_add_hwmon_sysfs(tsc->zone);
 368                if (ret)
 369                        goto error_unregister;
 370
 371                ret = devm_add_action_or_reset(dev, rcar_gen3_hwmon_action, zone);
 372                if (ret)
 373                        goto error_unregister;
 374
 375                ret = of_thermal_get_ntrips(tsc->zone);
 376                if (ret < 0)
 377                        goto error_unregister;
 378
 379                dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
 380        }
 381
 382        priv->num_tscs = i;
 383
 384        if (!priv->num_tscs) {
 385                ret = -ENODEV;
 386                goto error_unregister;
 387        }
 388
 389        return 0;
 390
 391error_unregister:
 392        rcar_gen3_thermal_remove(pdev);
 393
 394        return ret;
 395}
 396
 397static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 398{
 399        struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 400        unsigned int i;
 401
 402        for (i = 0; i < priv->num_tscs; i++) {
 403                struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 404
 405                priv->thermal_init(tsc);
 406        }
 407
 408        return 0;
 409}
 410
 411static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, NULL,
 412                         rcar_gen3_thermal_resume);
 413
 414static struct platform_driver rcar_gen3_thermal_driver = {
 415        .driver = {
 416                .name   = "rcar_gen3_thermal",
 417                .pm = &rcar_gen3_thermal_pm_ops,
 418                .of_match_table = rcar_gen3_thermal_dt_ids,
 419        },
 420        .probe          = rcar_gen3_thermal_probe,
 421        .remove         = rcar_gen3_thermal_remove,
 422};
 423module_platform_driver(rcar_gen3_thermal_driver);
 424
 425MODULE_LICENSE("GPL v2");
 426MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
 427MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");
 428
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