LXR linux/drivers/hwmon/mlxreg-fan.c

   1// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
   2//
   3// Copyright (c) 2018 Mellanox Technologies. All rights reserved.
   4// Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>
   5
   6#include <linux/bitops.h>
   7#include <linux/device.h>
   8#include <linux/hwmon.h>
   9#include <linux/module.h>
  10#include <linux/platform_data/mlxreg.h>
  11#include <linux/platform_device.h>
  12#include <linux/regmap.h>
  13#include <linux/thermal.h>
  14
  15#define MLXREG_FAN_MAX_TACHO            12
  16#define MLXREG_FAN_MAX_STATE            10
  17#define MLXREG_FAN_MIN_DUTY             51      /* 20% */
  18#define MLXREG_FAN_MAX_DUTY             255     /* 100% */
  19/*
  20 * Minimum and maximum FAN allowed speed in percent: from 20% to 100%. Values
  21 * MLXREG_FAN_MAX_STATE + x, where x is between 2 and 10 are used for
  22 * setting FAN speed dynamic minimum. For example, if value is set to 14 (40%)
  23 * cooling levels vector will be set to 4, 4, 4, 4, 4, 5, 6, 7, 8, 9, 10 to
  24 * introduce PWM speed in percent: 40, 40, 40, 40, 40, 50, 60. 70, 80, 90, 100.
  25 */
  26#define MLXREG_FAN_SPEED_MIN                    (MLXREG_FAN_MAX_STATE + 2)
  27#define MLXREG_FAN_SPEED_MAX                    (MLXREG_FAN_MAX_STATE * 2)
  28#define MLXREG_FAN_SPEED_MIN_LEVEL              2       /* 20 percent */
  29#define MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF  44
  30#define MLXREG_FAN_TACHO_DIV_MIN                283
  31#define MLXREG_FAN_TACHO_DIV_DEF                (MLXREG_FAN_TACHO_DIV_MIN * 4)
  32#define MLXREG_FAN_TACHO_DIV_SCALE_MAX  64
  33/*
  34 * FAN datasheet defines the formula for RPM calculations as RPM = 15/t-high.
  35 * The logic in a programmable device measures the time t-high by sampling the
  36 * tachometer every t-sample (with the default value 11.32 uS) and increment
  37 * a counter (N) as long as the pulse has not change:
  38 * RPM = 15 / (t-sample * (K + Regval)), where:
  39 * Regval: is the value read from the programmable device register;
  40 *  - 0xff - represents tachometer fault;
  41 *  - 0xfe - represents tachometer minimum value , which is 4444 RPM;
  42 *  - 0x00 - represents tachometer maximum value , which is 300000 RPM;
  43 * K: is 44 and it represents the minimum allowed samples per pulse;
  44 * N: is equal K + Regval;
  45 * In order to calculate RPM from the register value the following formula is
  46 * used: RPM = 15 / ((Regval + K) * 11.32) * 10^(-6)), which in  the
  47 * default case is modified to:
  48 * RPM = 15000000 * 100 / ((Regval + 44) * 1132);
  49 * - for Regval 0x00, RPM will be 15000000 * 100 / (44 * 1132) = 30115;
  50 * - for Regval 0xfe, RPM will be 15000000 * 100 / ((254 + 44) * 1132) = 4446;
  51 * In common case the formula is modified to:
  52 * RPM = 15000000 * 100 / ((Regval + samples) * divider).
  53 */
  54#define MLXREG_FAN_GET_RPM(rval, d, s)  (DIV_ROUND_CLOSEST(15000000 * 100, \
  55                                         ((rval) + (s)) * (d)))
  56#define MLXREG_FAN_GET_FAULT(val, mask) ((val) == (mask))
  57#define MLXREG_FAN_PWM_DUTY2STATE(duty) (DIV_ROUND_CLOSEST((duty) *     \
  58                                         MLXREG_FAN_MAX_STATE,          \
  59                                         MLXREG_FAN_MAX_DUTY))
  60#define MLXREG_FAN_PWM_STATE2DUTY(stat) (DIV_ROUND_CLOSEST((stat) *     \
  61                                         MLXREG_FAN_MAX_DUTY,           \
  62                                         MLXREG_FAN_MAX_STATE))
  63
  64/*
  65 * struct mlxreg_fan_tacho - tachometer data (internal use):
  66 *
  67 * @connected: indicates if tachometer is connected;
  68 * @reg: register offset;
  69 * @mask: fault mask;
  70 */
  71struct mlxreg_fan_tacho {
  72        bool connected;
  73        u32 reg;
  74        u32 mask;
  75};
  76
  77/*
  78 * struct mlxreg_fan_pwm - PWM data (internal use):
  79 *
  80 * @connected: indicates if PWM is connected;
  81 * @reg: register offset;
  82 */
  83struct mlxreg_fan_pwm {
  84        bool connected;
  85        u32 reg;
  86};
  87
  88/*
  89 * struct mlxreg_fan - private data (internal use):
  90 *
  91 * @dev: basic device;
  92 * @regmap: register map of parent device;
  93 * @tacho: tachometer data;
  94 * @pwm: PWM data;
  95 * @samples: minimum allowed samples per pulse;
  96 * @divider: divider value for tachometer RPM calculation;
  97 * @cooling: cooling device levels;
  98 * @cdev: cooling device;
  99 */
 100struct mlxreg_fan {
 101        struct device *dev;
 102        void *regmap;
 103        struct mlxreg_core_platform_data *pdata;
 104        struct mlxreg_fan_tacho tacho[MLXREG_FAN_MAX_TACHO];
 105        struct mlxreg_fan_pwm pwm;
 106        int samples;
 107        int divider;
 108        u8 cooling_levels[MLXREG_FAN_MAX_STATE + 1];
 109        struct thermal_cooling_device *cdev;
 110};
 111
 112static int
 113mlxreg_fan_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 114                int channel, long *val)
 115{
 116        struct mlxreg_fan *fan = dev_get_drvdata(dev);
 117        struct mlxreg_fan_tacho *tacho;
 118        u32 regval;
 119        int err;
 120
 121        switch (type) {
 122        case hwmon_fan:
 123                tacho = &fan->tacho[channel];
 124                switch (attr) {
 125                case hwmon_fan_input:
 126                        err = regmap_read(fan->regmap, tacho->reg, &regval);
 127                        if (err)
 128                                return err;
 129
 130                        *val = MLXREG_FAN_GET_RPM(regval, fan->divider,
 131                                                  fan->samples);
 132                        break;
 133
 134                case hwmon_fan_fault:
 135                        err = regmap_read(fan->regmap, tacho->reg, &regval);
 136                        if (err)
 137                                return err;
 138
 139                        *val = MLXREG_FAN_GET_FAULT(regval, tacho->mask);
 140                        break;
 141
 142                default:
 143                        return -EOPNOTSUPP;
 144                }
 145                break;
 146
 147        case hwmon_pwm:
 148                switch (attr) {
 149                case hwmon_pwm_input:
 150                        err = regmap_read(fan->regmap, fan->pwm.reg, &regval);
 151                        if (err)
 152                                return err;
 153
 154                        *val = regval;
 155                        break;
 156
 157                default:
 158                        return -EOPNOTSUPP;
 159                }
 160                break;
 161
 162        default:
 163                return -EOPNOTSUPP;
 164        }
 165
 166        return 0;
 167}
 168
 169static int
 170mlxreg_fan_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 171                 int channel, long val)
 172{
 173        struct mlxreg_fan *fan = dev_get_drvdata(dev);
 174
 175        switch (type) {
 176        case hwmon_pwm:
 177                switch (attr) {
 178                case hwmon_pwm_input:
 179                        if (val < MLXREG_FAN_MIN_DUTY ||
 180                            val > MLXREG_FAN_MAX_DUTY)
 181                                return -EINVAL;
 182                        return regmap_write(fan->regmap, fan->pwm.reg, val);
 183                default:
 184                        return -EOPNOTSUPP;
 185                }
 186                break;
 187
 188        default:
 189                return -EOPNOTSUPP;
 190        }
 191
 192        return -EOPNOTSUPP;
 193}
 194
 195static umode_t
 196mlxreg_fan_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
 197                      int channel)
 198{
 199        switch (type) {
 200        case hwmon_fan:
 201                if (!(((struct mlxreg_fan *)data)->tacho[channel].connected))
 202                        return 0;
 203
 204                switch (attr) {
 205                case hwmon_fan_input:
 206                case hwmon_fan_fault:
 207                        return 0444;
 208                default:
 209                        break;
 210                }
 211                break;
 212
 213        case hwmon_pwm:
 214                if (!(((struct mlxreg_fan *)data)->pwm.connected))
 215                        return 0;
 216
 217                switch (attr) {
 218                case hwmon_pwm_input:
 219                        return 0644;
 220                default:
 221                        break;
 222                }
 223                break;
 224
 225        default:
 226                break;
 227        }
 228
 229        return 0;
 230}
 231
 232static const struct hwmon_channel_info *mlxreg_fan_hwmon_info[] = {
 233        HWMON_CHANNEL_INFO(fan,
 234                           HWMON_F_INPUT | HWMON_F_FAULT,
 235                           HWMON_F_INPUT | HWMON_F_FAULT,
 236                           HWMON_F_INPUT | HWMON_F_FAULT,
 237                           HWMON_F_INPUT | HWMON_F_FAULT,
 238                           HWMON_F_INPUT | HWMON_F_FAULT,
 239                           HWMON_F_INPUT | HWMON_F_FAULT,
 240                           HWMON_F_INPUT | HWMON_F_FAULT,
 241                           HWMON_F_INPUT | HWMON_F_FAULT,
 242                           HWMON_F_INPUT | HWMON_F_FAULT,
 243                           HWMON_F_INPUT | HWMON_F_FAULT,
 244                           HWMON_F_INPUT | HWMON_F_FAULT,
 245                           HWMON_F_INPUT | HWMON_F_FAULT),
 246        HWMON_CHANNEL_INFO(pwm,
 247                           HWMON_PWM_INPUT),
 248        NULL
 249};
 250
 251static const struct hwmon_ops mlxreg_fan_hwmon_hwmon_ops = {
 252        .is_visible = mlxreg_fan_is_visible,
 253        .read = mlxreg_fan_read,
 254        .write = mlxreg_fan_write,
 255};
 256
 257static const struct hwmon_chip_info mlxreg_fan_hwmon_chip_info = {
 258        .ops = &mlxreg_fan_hwmon_hwmon_ops,
 259        .info = mlxreg_fan_hwmon_info,
 260};
 261
 262static int mlxreg_fan_get_max_state(struct thermal_cooling_device *cdev,
 263                                    unsigned long *state)
 264{
 265        *state = MLXREG_FAN_MAX_STATE;
 266        return 0;
 267}
 268
 269static int mlxreg_fan_get_cur_state(struct thermal_cooling_device *cdev,
 270                                    unsigned long *state)
 271
 272{
 273        struct mlxreg_fan *fan = cdev->devdata;
 274        u32 regval;
 275        int err;
 276
 277        err = regmap_read(fan->regmap, fan->pwm.reg, &regval);
 278        if (err) {
 279                dev_err(fan->dev, "Failed to query PWM duty\n");
 280                return err;
 281        }
 282
 283        *state = MLXREG_FAN_PWM_DUTY2STATE(regval);
 284
 285        return 0;
 286}
 287
 288static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
 289                                    unsigned long state)
 290
 291{
 292        struct mlxreg_fan *fan = cdev->devdata;
 293        unsigned long cur_state;
 294        u32 regval;
 295        int i;
 296        int err;
 297
 298        /*
 299         * Verify if this request is for changing allowed FAN dynamical
 300         * minimum. If it is - update cooling levels accordingly and update
 301         * state, if current state is below the newly requested minimum state.
 302         * For example, if current state is 5, and minimal state is to be
 303         * changed from 4 to 6, fan->cooling_levels[0 to 5] will be changed all
 304         * from 4 to 6. And state 5 (fan->cooling_levels[4]) should be
 305         * overwritten.
 306         */
 307        if (state >= MLXREG_FAN_SPEED_MIN && state <= MLXREG_FAN_SPEED_MAX) {
 308                state -= MLXREG_FAN_MAX_STATE;
 309                for (i = 0; i < state; i++)
 310                        fan->cooling_levels[i] = state;
 311                for (i = state; i <= MLXREG_FAN_MAX_STATE; i++)
 312                        fan->cooling_levels[i] = i;
 313
 314                err = regmap_read(fan->regmap, fan->pwm.reg, &regval);
 315                if (err) {
 316                        dev_err(fan->dev, "Failed to query PWM duty\n");
 317                        return err;
 318                }
 319
 320                cur_state = MLXREG_FAN_PWM_DUTY2STATE(regval);
 321                if (state < cur_state)
 322                        return 0;
 323
 324                state = cur_state;
 325        }
 326
 327        if (state > MLXREG_FAN_MAX_STATE)
 328                return -EINVAL;
 329
 330        /* Normalize the state to the valid speed range. */
 331        state = fan->cooling_levels[state];
 332        err = regmap_write(fan->regmap, fan->pwm.reg,
 333                           MLXREG_FAN_PWM_STATE2DUTY(state));
 334        if (err) {
 335                dev_err(fan->dev, "Failed to write PWM duty\n");
 336                return err;
 337        }
 338        return 0;
 339}
 340
 341static const struct thermal_cooling_device_ops mlxreg_fan_cooling_ops = {
 342        .get_max_state  = mlxreg_fan_get_max_state,
 343        .get_cur_state  = mlxreg_fan_get_cur_state,
 344        .set_cur_state  = mlxreg_fan_set_cur_state,
 345};
 346
 347static int mlxreg_fan_connect_verify(struct mlxreg_fan *fan,
 348                                     struct mlxreg_core_data *data)
 349{
 350        u32 regval;
 351        int err;
 352
 353        err = regmap_read(fan->regmap, data->capability, &regval);
 354        if (err) {
 355                dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
 356                        data->capability);
 357                return err;
 358        }
 359
 360        return !!(regval & data->bit);
 361}
 362
 363static int mlxreg_fan_speed_divider_get(struct mlxreg_fan *fan,
 364                                        struct mlxreg_core_data *data)
 365{
 366        u32 regval;
 367        int err;
 368
 369        err = regmap_read(fan->regmap, data->capability, &regval);
 370        if (err) {
 371                dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
 372                        data->capability);
 373                return err;
 374        }
 375
 376        /*
 377         * Set divider value according to the capability register, in case it
 378         * contains valid value. Otherwise use default value. The purpose of
 379         * this validation is to protect against the old hardware, in which
 380         * this register can return zero.
 381         */
 382        if (regval > 0 && regval <= MLXREG_FAN_TACHO_DIV_SCALE_MAX)
 383                fan->divider = regval * MLXREG_FAN_TACHO_DIV_MIN;
 384
 385        return 0;
 386}
 387
 388static int mlxreg_fan_config(struct mlxreg_fan *fan,
 389                             struct mlxreg_core_platform_data *pdata)
 390{
 391        struct mlxreg_core_data *data = pdata->data;
 392        bool configured = false;
 393        int tacho_num = 0, i;
 394        int err;
 395
 396        fan->samples = MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF;
 397        fan->divider = MLXREG_FAN_TACHO_DIV_DEF;
 398        for (i = 0; i < pdata->counter; i++, data++) {
 399                if (strnstr(data->label, "tacho", sizeof(data->label))) {
 400                        if (tacho_num == MLXREG_FAN_MAX_TACHO) {
 401                                dev_err(fan->dev, "too many tacho entries: %s\n",
 402                                        data->label);
 403                                return -EINVAL;
 404                        }
 405
 406                        if (data->capability) {
 407                                err = mlxreg_fan_connect_verify(fan, data);
 408                                if (err < 0)
 409                                        return err;
 410                                else if (!err) {
 411                                        tacho_num++;
 412                                        continue;
 413                                }
 414                        }
 415
 416                        fan->tacho[tacho_num].reg = data->reg;
 417                        fan->tacho[tacho_num].mask = data->mask;
 418                        fan->tacho[tacho_num++].connected = true;
 419                } else if (strnstr(data->label, "pwm", sizeof(data->label))) {
 420                        if (fan->pwm.connected) {
 421                                dev_err(fan->dev, "duplicate pwm entry: %s\n",
 422                                        data->label);
 423                                return -EINVAL;
 424                        }
 425                        fan->pwm.reg = data->reg;
 426                        fan->pwm.connected = true;
 427                } else if (strnstr(data->label, "conf", sizeof(data->label))) {
 428                        if (configured) {
 429                                dev_err(fan->dev, "duplicate conf entry: %s\n",
 430                                        data->label);
 431                                return -EINVAL;
 432                        }
 433                        /* Validate that conf parameters are not zeros. */
 434                        if (!data->mask && !data->bit && !data->capability) {
 435                                dev_err(fan->dev, "invalid conf entry params: %s\n",
 436                                        data->label);
 437                                return -EINVAL;
 438                        }
 439                        if (data->capability) {
 440                                err = mlxreg_fan_speed_divider_get(fan, data);
 441                                if (err)
 442                                        return err;
 443                        } else {
 444                                if (data->mask)
 445                                        fan->samples = data->mask;
 446                                if (data->bit)
 447                                        fan->divider = data->bit;
 448                        }
 449                        configured = true;
 450                } else {
 451                        dev_err(fan->dev, "invalid label: %s\n", data->label);
 452                        return -EINVAL;
 453                }
 454        }
 455
 456        /* Init cooling levels per PWM state. */
 457        for (i = 0; i < MLXREG_FAN_SPEED_MIN_LEVEL; i++)
 458                fan->cooling_levels[i] = MLXREG_FAN_SPEED_MIN_LEVEL;
 459        for (i = MLXREG_FAN_SPEED_MIN_LEVEL; i <= MLXREG_FAN_MAX_STATE; i++)
 460                fan->cooling_levels[i] = i;
 461
 462        return 0;
 463}
 464
 465static int mlxreg_fan_probe(struct platform_device *pdev)
 466{
 467        struct mlxreg_core_platform_data *pdata;
 468        struct device *dev = &pdev->dev;
 469        struct mlxreg_fan *fan;
 470        struct device *hwm;
 471        int err;
 472
 473        pdata = dev_get_platdata(dev);
 474        if (!pdata) {
 475                dev_err(dev, "Failed to get platform data.\n");
 476                return -EINVAL;
 477        }
 478
 479        fan = devm_kzalloc(dev, sizeof(*fan), GFP_KERNEL);
 480        if (!fan)
 481                return -ENOMEM;
 482
 483        fan->dev = dev;
 484        fan->regmap = pdata->regmap;
 485
 486        err = mlxreg_fan_config(fan, pdata);
 487        if (err)
 488                return err;
 489
 490        hwm = devm_hwmon_device_register_with_info(dev, "mlxreg_fan",
 491                                                   fan,
 492                                                   &mlxreg_fan_hwmon_chip_info,
 493                                                   NULL);
 494        if (IS_ERR(hwm)) {
 495                dev_err(dev, "Failed to register hwmon device\n");
 496                return PTR_ERR(hwm);
 497        }
 498
 499        if (IS_REACHABLE(CONFIG_THERMAL)) {
 500                fan->cdev = devm_thermal_of_cooling_device_register(dev,
 501                        NULL, "mlxreg_fan", fan, &mlxreg_fan_cooling_ops);
 502                if (IS_ERR(fan->cdev)) {
 503                        dev_err(dev, "Failed to register cooling device\n");
 504                        return PTR_ERR(fan->cdev);
 505                }
 506        }
 507
 508        return 0;
 509}
 510
 511static struct platform_driver mlxreg_fan_driver = {
 512        .driver = {
 513            .name = "mlxreg-fan",
 514        },
 515        .probe = mlxreg_fan_probe,
 516};
 517
 518module_platform_driver(mlxreg_fan_driver);
 519
 520MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
 521MODULE_DESCRIPTION("Mellanox FAN driver");
 522MODULE_LICENSE("GPL");
 523MODULE_ALIAS("platform:mlxreg-fan");
 524