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