drivers/hwmon/max31790.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * max31790.c - Part of lm_sensors, Linux kernel modules for hardware
   4  *             monitoring.
   5  *
   6  * (C) 2015 by Il Han <corone.il.han@gmail.com>
   7  */
   8
   9 #include <linux/err.h>
  10 #include <linux/hwmon.h>
  11 #include <linux/i2c.h>
  12 #include <linux/init.h>
  13 #include <linux/jiffies.h>
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16
  17 /* MAX31790 registers */
  18 #define MAX31790_REG_GLOBAL_CONFIG      0x00
  19 #define MAX31790_REG_FAN_CONFIG(ch)     (0x02 + (ch))
  20 #define MAX31790_REG_FAN_DYNAMICS(ch)   (0x08 + (ch))
  21 #define MAX31790_REG_FAN_FAULT_STATUS2  0x10
  22 #define MAX31790_REG_FAN_FAULT_STATUS1  0x11
  23 #define MAX31790_REG_TACH_COUNT(ch)     (0x18 + (ch) * 2)
  24 #define MAX31790_REG_PWM_DUTY_CYCLE(ch) (0x30 + (ch) * 2)
  25 #define MAX31790_REG_PWMOUT(ch)         (0x40 + (ch) * 2)
  26 #define MAX31790_REG_TARGET_COUNT(ch)   (0x50 + (ch) * 2)
  27
  28 /* Fan Config register bits */
  29 #define MAX31790_FAN_CFG_RPM_MODE       0x80
  30 #define MAX31790_FAN_CFG_CTRL_MON       0x10
  31 #define MAX31790_FAN_CFG_TACH_INPUT_EN  0x08
  32 #define MAX31790_FAN_CFG_TACH_INPUT     0x01
  33
  34 /* Fan Dynamics register bits */
  35 #define MAX31790_FAN_DYN_SR_SHIFT       5
  36 #define MAX31790_FAN_DYN_SR_MASK        0xE0
  37 #define SR_FROM_REG(reg)                (((reg) & MAX31790_FAN_DYN_SR_MASK) \
  38                                          >> MAX31790_FAN_DYN_SR_SHIFT)
  39
  40 #define FAN_RPM_MIN                     120
  41 #define FAN_RPM_MAX                     7864320
  42
  43 #define FAN_COUNT_REG_MAX               0xffe0
  44
  45 #define RPM_FROM_REG(reg, sr)           (((reg) >> 4) ? \
  46                                          ((60 * (sr) * 8192) / ((reg) >> 4)) : \
  47                                          FAN_RPM_MAX)
  48 #define RPM_TO_REG(rpm, sr)             ((60 * (sr) * 8192) / ((rpm) * 2))
  49
  50 #define NR_CHANNEL                      6
  51
  52 /*
  53  * Client data (each client gets its own)
  54  */
  55 struct max31790_data {
  56         struct i2c_client *client;
  57         struct mutex update_lock;
  58         bool valid; /* zero until following fields are valid */
  59         unsigned long last_updated; /* in jiffies */
  60
  61         /* register values */
  62         u8 fan_config[NR_CHANNEL];
  63         u8 fan_dynamics[NR_CHANNEL];
  64         u16 fault_status;
  65         u16 tach[NR_CHANNEL * 2];
  66         u16 pwm[NR_CHANNEL];
  67         u16 target_count[NR_CHANNEL];
  68 };
  69
  70 static struct max31790_data *max31790_update_device(struct device *dev)
  71 {
  72         struct max31790_data *data = dev_get_drvdata(dev);
  73         struct i2c_client *client = data->client;
  74         struct max31790_data *ret = data;
  75         int i;
  76         int rv;
  77
  78         mutex_lock(&data->update_lock);
  79
  80         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
  81                 rv = i2c_smbus_read_byte_data(client,
  82                                 MAX31790_REG_FAN_FAULT_STATUS1);
  83                 if (rv < 0)
  84                         goto abort;
  85                 data->fault_status |= rv & 0x3F;
  86
  87                 rv = i2c_smbus_read_byte_data(client,
  88                                 MAX31790_REG_FAN_FAULT_STATUS2);
  89                 if (rv < 0)
  90                         goto abort;
  91                 data->fault_status |= (rv & 0x3F) << 6;
  92
  93                 for (i = 0; i < NR_CHANNEL; i++) {
  94                         rv = i2c_smbus_read_word_swapped(client,
  95                                         MAX31790_REG_TACH_COUNT(i));
  96                         if (rv < 0)
  97                                 goto abort;
  98                         data->tach[i] = rv;
  99
 100                         if (data->fan_config[i]
 101                             & MAX31790_FAN_CFG_TACH_INPUT) {
 102                                 rv = i2c_smbus_read_word_swapped(client,
 103                                         MAX31790_REG_TACH_COUNT(NR_CHANNEL
 104                                                                 + i));
 105                                 if (rv < 0)
 106                                         goto abort;
 107                                 data->tach[NR_CHANNEL + i] = rv;
 108                         } else {
 109                                 rv = i2c_smbus_read_word_swapped(client,
 110                                                 MAX31790_REG_PWM_DUTY_CYCLE(i));
 111                                 if (rv < 0)
 112                                         goto abort;
 113                                 data->pwm[i] = rv;
 114
 115                                 rv = i2c_smbus_read_word_swapped(client,
 116                                                 MAX31790_REG_TARGET_COUNT(i));
 117                                 if (rv < 0)
 118                                         goto abort;
 119                                 data->target_count[i] = rv;
 120                         }
 121                 }
 122
 123                 data->last_updated = jiffies;
 124                 data->valid = true;
 125         }
 126         goto done;
 127
 128 abort:
 129         data->valid = false;
 130         ret = ERR_PTR(rv);
 131
 132 done:
 133         mutex_unlock(&data->update_lock);
 134
 135         return ret;
 136 }
 137
 138 static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 };
 139
 140 static u8 get_tach_period(u8 fan_dynamics)
 141 {
 142         return tach_period[SR_FROM_REG(fan_dynamics)];
 143 }
 144
 145 static u8 bits_for_tach_period(int rpm)
 146 {
 147         u8 bits;
 148
 149         if (rpm < 500)
 150                 bits = 0x0;
 151         else if (rpm < 1000)
 152                 bits = 0x1;
 153         else if (rpm < 2000)
 154                 bits = 0x2;
 155         else if (rpm < 4000)
 156                 bits = 0x3;
 157         else if (rpm < 8000)
 158                 bits = 0x4;
 159         else
 160                 bits = 0x5;
 161
 162         return bits;
 163 }
 164
 165 static int max31790_read_fan(struct device *dev, u32 attr, int channel,
 166                              long *val)
 167 {
 168         struct max31790_data *data = max31790_update_device(dev);
 169         int sr, rpm;
 170
 171         if (IS_ERR(data))
 172                 return PTR_ERR(data);
 173
 174         switch (attr) {
 175         case hwmon_fan_input:
 176                 sr = get_tach_period(data->fan_dynamics[channel % NR_CHANNEL]);
 177                 if (data->tach[channel] == FAN_COUNT_REG_MAX)
 178                         rpm = 0;
 179                 else
 180                         rpm = RPM_FROM_REG(data->tach[channel], sr);
 181                 *val = rpm;
 182                 return 0;
 183         case hwmon_fan_target:
 184                 sr = get_tach_period(data->fan_dynamics[channel]);
 185                 rpm = RPM_FROM_REG(data->target_count[channel], sr);
 186                 *val = rpm;
 187                 return 0;
 188         case hwmon_fan_fault:
 189                 mutex_lock(&data->update_lock);
 190                 *val = !!(data->fault_status & (1 << channel));
 191                 data->fault_status &= ~(1 << channel);
 192                 /*
 193                  * If a fault bit is set, we need to write into one of the fan
 194                  * configuration registers to clear it. Note that this also
 195                  * clears the fault for the companion channel if enabled.
 196                  */
 197                 if (*val) {
 198                         int reg = MAX31790_REG_TARGET_COUNT(channel % NR_CHANNEL);
 199
 200                         i2c_smbus_write_byte_data(data->client, reg,
 201                                                   data->target_count[channel % NR_CHANNEL] >> 8);
 202                 }
 203                 mutex_unlock(&data->update_lock);
 204                 return 0;
 205         default:
 206                 return -EOPNOTSUPP;
 207         }
 208 }
 209
 210 static int max31790_write_fan(struct device *dev, u32 attr, int channel,
 211                               long val)
 212 {
 213         struct max31790_data *data = dev_get_drvdata(dev);
 214         struct i2c_client *client = data->client;
 215         int target_count;
 216         int err = 0;
 217         u8 bits;
 218         int sr;
 219
 220         mutex_lock(&data->update_lock);
 221
 222         switch (attr) {
 223         case hwmon_fan_target:
 224                 val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
 225                 bits = bits_for_tach_period(val);
 226                 data->fan_dynamics[channel] =
 227                         ((data->fan_dynamics[channel] &
 228                           ~MAX31790_FAN_DYN_SR_MASK) |
 229                          (bits << MAX31790_FAN_DYN_SR_SHIFT));
 230                 err = i2c_smbus_write_byte_data(client,
 231                                         MAX31790_REG_FAN_DYNAMICS(channel),
 232                                         data->fan_dynamics[channel]);
 233                 if (err < 0)
 234                         break;
 235
 236                 sr = get_tach_period(data->fan_dynamics[channel]);
 237                 target_count = RPM_TO_REG(val, sr);
 238                 target_count = clamp_val(target_count, 0x1, 0x7FF);
 239
 240                 data->target_count[channel] = target_count << 5;
 241
 242                 err = i2c_smbus_write_word_swapped(client,
 243                                         MAX31790_REG_TARGET_COUNT(channel),
 244                                         data->target_count[channel]);
 245                 break;
 246         default:
 247                 err = -EOPNOTSUPP;
 248                 break;
 249         }
 250
 251         mutex_unlock(&data->update_lock);
 252
 253         return err;
 254 }
 255
 256 static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
 257 {
 258         const struct max31790_data *data = _data;
 259         u8 fan_config = data->fan_config[channel % NR_CHANNEL];
 260
 261         switch (attr) {
 262         case hwmon_fan_input:
 263         case hwmon_fan_fault:
 264                 if (channel < NR_CHANNEL ||
 265                     (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
 266                         return 0444;
 267                 return 0;
 268         case hwmon_fan_target:
 269                 if (channel < NR_CHANNEL &&
 270                     !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
 271                         return 0644;
 272                 return 0;
 273         default:
 274                 return 0;
 275         }
 276 }
 277
 278 static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
 279                              long *val)
 280 {
 281         struct max31790_data *data = max31790_update_device(dev);
 282         u8 fan_config;
 283
 284         if (IS_ERR(data))
 285                 return PTR_ERR(data);
 286
 287         fan_config = data->fan_config[channel];
 288
 289         switch (attr) {
 290         case hwmon_pwm_input:
 291                 *val = data->pwm[channel] >> 8;
 292                 return 0;
 293         case hwmon_pwm_enable:
 294                 if (fan_config & MAX31790_FAN_CFG_CTRL_MON)
 295                         *val = 0;
 296                 else if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
 297                         *val = 2;
 298                 else
 299                         *val = 1;
 300                 return 0;
 301         default:
 302                 return -EOPNOTSUPP;
 303         }
 304 }
 305
 306 static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
 307                               long val)
 308 {
 309         struct max31790_data *data = dev_get_drvdata(dev);
 310         struct i2c_client *client = data->client;
 311         u8 fan_config;
 312         int err = 0;
 313
 314         mutex_lock(&data->update_lock);
 315
 316         switch (attr) {
 317         case hwmon_pwm_input:
 318                 if (val < 0 || val > 255) {
 319                         err = -EINVAL;
 320                         break;
 321                 }
 322                 data->valid = false;
 323                 err = i2c_smbus_write_word_swapped(client,
 324                                                    MAX31790_REG_PWMOUT(channel),
 325                                                    val << 8);
 326                 break;
 327         case hwmon_pwm_enable:
 328                 fan_config = data->fan_config[channel];
 329                 if (val == 0) {
 330                         fan_config |= MAX31790_FAN_CFG_CTRL_MON;
 331                         /*
 332                          * Disable RPM mode; otherwise disabling fan speed
 333                          * monitoring is not possible.
 334                          */
 335                         fan_config &= ~MAX31790_FAN_CFG_RPM_MODE;
 336                 } else if (val == 1) {
 337                         fan_config &= ~(MAX31790_FAN_CFG_CTRL_MON | MAX31790_FAN_CFG_RPM_MODE);
 338                 } else if (val == 2) {
 339                         fan_config &= ~MAX31790_FAN_CFG_CTRL_MON;
 340                         /*
 341                          * The chip sets MAX31790_FAN_CFG_TACH_INPUT_EN on its
 342                          * own if MAX31790_FAN_CFG_RPM_MODE is set.
 343                          * Do it here as well to reflect the actual register
 344                          * value in the cache.
 345                          */
 346                         fan_config |= (MAX31790_FAN_CFG_RPM_MODE | MAX31790_FAN_CFG_TACH_INPUT_EN);
 347                 } else {
 348                         err = -EINVAL;
 349                         break;
 350                 }
 351                 if (fan_config != data->fan_config[channel]) {
 352                         err = i2c_smbus_write_byte_data(client, MAX31790_REG_FAN_CONFIG(channel),
 353                                                         fan_config);
 354                         if (!err)
 355                                 data->fan_config[channel] = fan_config;
 356                 }
 357                 break;
 358         default:
 359                 err = -EOPNOTSUPP;
 360                 break;
 361         }
 362
 363         mutex_unlock(&data->update_lock);
 364
 365         return err;
 366 }
 367
 368 static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel)
 369 {
 370         const struct max31790_data *data = _data;
 371         u8 fan_config = data->fan_config[channel];
 372
 373         switch (attr) {
 374         case hwmon_pwm_input:
 375         case hwmon_pwm_enable:
 376                 if (!(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
 377                         return 0644;
 378                 return 0;
 379         default:
 380                 return 0;
 381         }
 382 }
 383
 384 static int max31790_read(struct device *dev, enum hwmon_sensor_types type,
 385                          u32 attr, int channel, long *val)
 386 {
 387         switch (type) {
 388         case hwmon_fan:
 389                 return max31790_read_fan(dev, attr, channel, val);
 390         case hwmon_pwm:
 391                 return max31790_read_pwm(dev, attr, channel, val);
 392         default:
 393                 return -EOPNOTSUPP;
 394         }
 395 }
 396
 397 static int max31790_write(struct device *dev, enum hwmon_sensor_types type,
 398                           u32 attr, int channel, long val)
 399 {
 400         switch (type) {
 401         case hwmon_fan:
 402                 return max31790_write_fan(dev, attr, channel, val);
 403         case hwmon_pwm:
 404                 return max31790_write_pwm(dev, attr, channel, val);
 405         default:
 406                 return -EOPNOTSUPP;
 407         }
 408 }
 409
 410 static umode_t max31790_is_visible(const void *data,
 411                                    enum hwmon_sensor_types type,
 412                                    u32 attr, int channel)
 413 {
 414         switch (type) {
 415         case hwmon_fan:
 416                 return max31790_fan_is_visible(data, attr, channel);
 417         case hwmon_pwm:
 418                 return max31790_pwm_is_visible(data, attr, channel);
 419         default:
 420                 return 0;
 421         }
 422 }
 423
 424 static const struct hwmon_channel_info *max31790_info[] = {
 425         HWMON_CHANNEL_INFO(fan,
 426                            HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
 427                            HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
 428                            HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
 429                            HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
 430                            HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
 431                            HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
 432                            HWMON_F_INPUT | HWMON_F_FAULT,
 433                            HWMON_F_INPUT | HWMON_F_FAULT,
 434                            HWMON_F_INPUT | HWMON_F_FAULT,
 435                            HWMON_F_INPUT | HWMON_F_FAULT,
 436                            HWMON_F_INPUT | HWMON_F_FAULT,
 437                            HWMON_F_INPUT | HWMON_F_FAULT),
 438         HWMON_CHANNEL_INFO(pwm,
 439                            HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
 440                            HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
 441                            HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
 442                            HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
 443                            HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
 444                            HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
 445         NULL
 446 };
 447
 448 static const struct hwmon_ops max31790_hwmon_ops = {
 449         .is_visible = max31790_is_visible,
 450         .read = max31790_read,
 451         .write = max31790_write,
 452 };
 453
 454 static const struct hwmon_chip_info max31790_chip_info = {
 455         .ops = &max31790_hwmon_ops,
 456         .info = max31790_info,
 457 };
 458
 459 static int max31790_init_client(struct i2c_client *client,
 460                                 struct max31790_data *data)
 461 {
 462         int i, rv;
 463
 464         for (i = 0; i < NR_CHANNEL; i++) {
 465                 rv = i2c_smbus_read_byte_data(client,
 466                                 MAX31790_REG_FAN_CONFIG(i));
 467                 if (rv < 0)
 468                         return rv;
 469                 data->fan_config[i] = rv;
 470
 471                 rv = i2c_smbus_read_byte_data(client,
 472                                 MAX31790_REG_FAN_DYNAMICS(i));
 473                 if (rv < 0)
 474                         return rv;
 475                 data->fan_dynamics[i] = rv;
 476         }
 477
 478         return 0;
 479 }
 480
 481 static int max31790_probe(struct i2c_client *client)
 482 {
 483         struct i2c_adapter *adapter = client->adapter;
 484         struct device *dev = &client->dev;
 485         struct max31790_data *data;
 486         struct device *hwmon_dev;
 487         int err;
 488
 489         if (!i2c_check_functionality(adapter,
 490                         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
 491                 return -ENODEV;
 492
 493         data = devm_kzalloc(dev, sizeof(struct max31790_data), GFP_KERNEL);
 494         if (!data)
 495                 return -ENOMEM;
 496
 497         data->client = client;
 498         mutex_init(&data->update_lock);
 499
 500         /*
 501          * Initialize the max31790 chip
 502          */
 503         err = max31790_init_client(client, data);
 504         if (err)
 505                 return err;
 506
 507         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 508                                                          data,
 509                                                          &max31790_chip_info,
 510                                                          NULL);
 511
 512         return PTR_ERR_OR_ZERO(hwmon_dev);
 513 }
 514
 515 static const struct i2c_device_id max31790_id[] = {
 516         { "max31790", 0 },
 517         { }
 518 };
 519 MODULE_DEVICE_TABLE(i2c, max31790_id);
 520
 521 static struct i2c_driver max31790_driver = {
 522         .class          = I2C_CLASS_HWMON,
 523         .probe_new      = max31790_probe,
 524         .driver = {
 525                 .name   = "max31790",
 526         },
 527         .id_table       = max31790_id,
 528 };
 529
 530 module_i2c_driver(max31790_driver);
 531
 532 MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>");
 533 MODULE_DESCRIPTION("MAX31790 sensor driver");
 534 MODULE_LICENSE("GPL");