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                         *val = MLXREG_FAN_GET_RPM(regval, fan->divider,
 129                                                   fan->samples);
 130                         break;
 131
 132                 case hwmon_fan_fault:
 133                         err = regmap_read(fan->regmap, tacho->reg, &regval);
 134                         if (err)
 135                                 return err;
 136
 137                         *val = MLXREG_FAN_GET_FAULT(regval, tacho->mask);
 138                         break;
 139
 140                 default:
 141                         return -EOPNOTSUPP;
 142                 }
 143                 break;
 144
 145         case hwmon_pwm:
 146                 switch (attr) {
 147                 case hwmon_pwm_input:
 148                         err = regmap_read(fan->regmap, fan->pwm.reg, &regval);
 149                         if (err)
 150                                 return err;
 151
 152                         *val = regval;
 153                         break;
 154
 155                 default:
 156                         return -EOPNOTSUPP;
 157                 }
 158                 break;
 159
 160         default:
 161                 return -EOPNOTSUPP;
 162         }
 163
 164         return 0;
 165 }
 166
 167 static int
 168 mlxreg_fan_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 169                  int channel, long val)
 170 {
 171         struct mlxreg_fan *fan = dev_get_drvdata(dev);
 172
 173         switch (type) {
 174         case hwmon_pwm:
 175                 switch (attr) {
 176                 case hwmon_pwm_input:
 177                         if (val < MLXREG_FAN_MIN_DUTY ||
 178                             val > MLXREG_FAN_MAX_DUTY)
 179                                 return -EINVAL;
 180                         return regmap_write(fan->regmap, fan->pwm.reg, val);
 181                 default:
 182                         return -EOPNOTSUPP;
 183                 }
 184                 break;
 185
 186         default:
 187                 return -EOPNOTSUPP;
 188         }
 189
 190         return -EOPNOTSUPP;
 191 }
 192
 193 static umode_t
 194 mlxreg_fan_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
 195                       int channel)
 196 {
 197         switch (type) {
 198         case hwmon_fan:
 199                 if (!(((struct mlxreg_fan *)data)->tacho[channel].connected))
 200                         return 0;
 201
 202                 switch (attr) {
 203                 case hwmon_fan_input:
 204                 case hwmon_fan_fault:
 205                         return 0444;
 206                 default:
 207                         break;
 208                 }
 209                 break;
 210
 211         case hwmon_pwm:
 212                 if (!(((struct mlxreg_fan *)data)->pwm.connected))
 213                         return 0;
 214
 215                 switch (attr) {
 216                 case hwmon_pwm_input:
 217                         return 0644;
 218                 default:
 219                         break;
 220                 }
 221                 break;
 222
 223         default:
 224                 break;
 225         }
 226
 227         return 0;
 228 }
 229
 230 static const u32 mlxreg_fan_hwmon_fan_config[] = {
 231         HWMON_F_INPUT | HWMON_F_FAULT,
 232         HWMON_F_INPUT | HWMON_F_FAULT,
 233         HWMON_F_INPUT | HWMON_F_FAULT,
 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         0
 244 };
 245
 246 static const struct hwmon_channel_info mlxreg_fan_hwmon_fan = {
 247         .type = hwmon_fan,
 248         .config = mlxreg_fan_hwmon_fan_config,
 249 };
 250
 251 static const u32 mlxreg_fan_hwmon_pwm_config[] = {
 252         HWMON_PWM_INPUT,
 253         0
 254 };
 255
 256 static const struct hwmon_channel_info mlxreg_fan_hwmon_pwm = {
 257         .type = hwmon_pwm,
 258         .config = mlxreg_fan_hwmon_pwm_config,
 259 };
 260
 261 static const struct hwmon_channel_info *mlxreg_fan_hwmon_info[] = {
 262         &mlxreg_fan_hwmon_fan,
 263         &mlxreg_fan_hwmon_pwm,
 264         NULL
 265 };
 266
 267 static const struct hwmon_ops mlxreg_fan_hwmon_hwmon_ops = {
 268         .is_visible = mlxreg_fan_is_visible,
 269         .read = mlxreg_fan_read,
 270         .write = mlxreg_fan_write,
 271 };
 272
 273 static const struct hwmon_chip_info mlxreg_fan_hwmon_chip_info = {
 274         .ops = &mlxreg_fan_hwmon_hwmon_ops,
 275         .info = mlxreg_fan_hwmon_info,
 276 };
 277
 278 static int mlxreg_fan_get_max_state(struct thermal_cooling_device *cdev,
 279                                     unsigned long *state)
 280 {
 281         *state = MLXREG_FAN_MAX_STATE;
 282         return 0;
 283 }
 284
 285 static int mlxreg_fan_get_cur_state(struct thermal_cooling_device *cdev,
 286                                     unsigned long *state)
 287
 288 {
 289         struct mlxreg_fan *fan = cdev->devdata;
 290         u32 regval;
 291         int err;
 292
 293         err = regmap_read(fan->regmap, fan->pwm.reg, &regval);
 294         if (err) {
 295                 dev_err(fan->dev, "Failed to query PWM duty\n");
 296                 return err;
 297         }
 298
 299         *state = MLXREG_FAN_PWM_DUTY2STATE(regval);
 300
 301         return 0;
 302 }
 303
 304 static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
 305                                     unsigned long state)
 306
 307 {
 308         struct mlxreg_fan *fan = cdev->devdata;
 309         unsigned long cur_state;
 310         u32 regval;
 311         int i;
 312         int err;
 313
 314         /*
 315          * Verify if this request is for changing allowed FAN dynamical
 316          * minimum. If it is - update cooling levels accordingly and update
 317          * state, if current state is below the newly requested minimum state.
 318          * For example, if current state is 5, and minimal state is to be
 319          * changed from 4 to 6, fan->cooling_levels[0 to 5] will be changed all
 320          * from 4 to 6. And state 5 (fan->cooling_levels[4]) should be
 321          * overwritten.
 322          */
 323         if (state >= MLXREG_FAN_SPEED_MIN && state <= MLXREG_FAN_SPEED_MAX) {
 324                 state -= MLXREG_FAN_MAX_STATE;
 325                 for (i = 0; i < state; i++)
 326                         fan->cooling_levels[i] = state;
 327                 for (i = state; i <= MLXREG_FAN_MAX_STATE; i++)
 328                         fan->cooling_levels[i] = i;
 329
 330                 err = regmap_read(fan->regmap, fan->pwm.reg, &regval);
 331                 if (err) {
 332                         dev_err(fan->dev, "Failed to query PWM duty\n");
 333                         return err;
 334                 }
 335
 336                 cur_state = MLXREG_FAN_PWM_DUTY2STATE(regval);
 337                 if (state < cur_state)
 338                         return 0;
 339
 340                 state = cur_state;
 341         }
 342
 343         if (state > MLXREG_FAN_MAX_STATE)
 344                 return -EINVAL;
 345
 346         /* Normalize the state to the valid speed range. */
 347         state = fan->cooling_levels[state];
 348         err = regmap_write(fan->regmap, fan->pwm.reg,
 349                            MLXREG_FAN_PWM_STATE2DUTY(state));
 350         if (err) {
 351                 dev_err(fan->dev, "Failed to write PWM duty\n");
 352                 return err;
 353         }
 354         return 0;
 355 }
 356
 357 static const struct thermal_cooling_device_ops mlxreg_fan_cooling_ops = {
 358         .get_max_state  = mlxreg_fan_get_max_state,
 359         .get_cur_state  = mlxreg_fan_get_cur_state,
 360         .set_cur_state  = mlxreg_fan_set_cur_state,
 361 };
 362
 363 static int mlxreg_fan_config(struct mlxreg_fan *fan,
 364                              struct mlxreg_core_platform_data *pdata)
 365 {
 366         struct mlxreg_core_data *data = pdata->data;
 367         bool configured = false;
 368         int tacho_num = 0, i;
 369
 370         fan->samples = MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF;
 371         fan->divider = MLXREG_FAN_TACHO_DIVIDER_DEF;
 372         for (i = 0; i < pdata->counter; i++, data++) {
 373                 if (strnstr(data->label, "tacho", sizeof(data->label))) {
 374                         if (tacho_num == MLXREG_FAN_MAX_TACHO) {
 375                                 dev_err(fan->dev, "too many tacho entries: %s\n",
 376                                         data->label);
 377                                 return -EINVAL;
 378                         }
 379                         fan->tacho[tacho_num].reg = data->reg;
 380                         fan->tacho[tacho_num].mask = data->mask;
 381                         fan->tacho[tacho_num++].connected = true;
 382                 } else if (strnstr(data->label, "pwm", sizeof(data->label))) {
 383                         if (fan->pwm.connected) {
 384                                 dev_err(fan->dev, "duplicate pwm entry: %s\n",
 385                                         data->label);
 386                                 return -EINVAL;
 387                         }
 388                         fan->pwm.reg = data->reg;
 389                         fan->pwm.connected = true;
 390                 } else if (strnstr(data->label, "conf", sizeof(data->label))) {
 391                         if (configured) {
 392                                 dev_err(fan->dev, "duplicate conf entry: %s\n",
 393                                         data->label);
 394                                 return -EINVAL;
 395                         }
 396                         /* Validate that conf parameters are not zeros. */
 397                         if (!data->mask || !data->bit) {
 398                                 dev_err(fan->dev, "invalid conf entry params: %s\n",
 399                                         data->label);
 400                                 return -EINVAL;
 401                         }
 402                         fan->samples = data->mask;
 403                         fan->divider = data->bit;
 404                         configured = true;
 405                 } else {
 406                         dev_err(fan->dev, "invalid label: %s\n", data->label);
 407                         return -EINVAL;
 408                 }
 409         }
 410
 411         /* Init cooling levels per PWM state. */
 412         for (i = 0; i < MLXREG_FAN_SPEED_MIN_LEVEL; i++)
 413                 fan->cooling_levels[i] = MLXREG_FAN_SPEED_MIN_LEVEL;
 414         for (i = MLXREG_FAN_SPEED_MIN_LEVEL; i <= MLXREG_FAN_MAX_STATE; i++)
 415                 fan->cooling_levels[i] = i;
 416
 417         return 0;
 418 }
 419
 420 static int mlxreg_fan_probe(struct platform_device *pdev)
 421 {
 422         struct mlxreg_core_platform_data *pdata;
 423         struct mlxreg_fan *fan;
 424         struct device *hwm;
 425         int err;
 426
 427         pdata = dev_get_platdata(&pdev->dev);
 428         if (!pdata) {
 429                 dev_err(&pdev->dev, "Failed to get platform data.\n");
 430                 return -EINVAL;
 431         }
 432
 433         fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
 434         if (!fan)
 435                 return -ENOMEM;
 436
 437         fan->dev = &pdev->dev;
 438         fan->regmap = pdata->regmap;
 439         platform_set_drvdata(pdev, fan);
 440
 441         err = mlxreg_fan_config(fan, pdata);
 442         if (err)
 443                 return err;
 444
 445         hwm = devm_hwmon_device_register_with_info(&pdev->dev, "mlxreg_fan",
 446                                                    fan,
 447                                                    &mlxreg_fan_hwmon_chip_info,
 448                                                    NULL);
 449         if (IS_ERR(hwm)) {
 450                 dev_err(&pdev->dev, "Failed to register hwmon device\n");
 451                 return PTR_ERR(hwm);
 452         }
 453
 454         if (IS_REACHABLE(CONFIG_THERMAL)) {
 455                 fan->cdev = thermal_cooling_device_register("mlxreg_fan", fan,
 456                                                 &mlxreg_fan_cooling_ops);
 457                 if (IS_ERR(fan->cdev)) {
 458                         dev_err(&pdev->dev, "Failed to register cooling device\n");
 459                         return PTR_ERR(fan->cdev);
 460                 }
 461         }
 462
 463         return 0;
 464 }
 465
 466 static int mlxreg_fan_remove(struct platform_device *pdev)
 467 {
 468         struct mlxreg_fan *fan = platform_get_drvdata(pdev);
 469
 470         if (IS_REACHABLE(CONFIG_THERMAL))
 471                 thermal_cooling_device_unregister(fan->cdev);
 472
 473         return 0;
 474 }
 475
 476 static struct platform_driver mlxreg_fan_driver = {
 477         .driver = {
 478             .name = "mlxreg-fan",
 479         },
 480         .probe = mlxreg_fan_probe,
 481         .remove = mlxreg_fan_remove,
 482 };
 483
 484 module_platform_driver(mlxreg_fan_driver);
 485
 486 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
 487 MODULE_DESCRIPTION("Mellanox FAN driver");
 488 MODULE_LICENSE("GPL");
 489 MODULE_ALIAS("platform:mlxreg-fan");