drivers/hwmon/max6650.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * max6650.c - Part of lm_sensors, Linux kernel modules for hardware
   4  *             monitoring.
   5  *
   6  * (C) 2007 by Hans J. Koch <hjk@hansjkoch.de>
   7  *
   8  * based on code written by John Morris <john.morris@spirentcom.com>
   9  * Copyright (c) 2003 Spirent Communications
  10  * and Claus Gindhart <claus.gindhart@kontron.com>
  11  *
  12  * This module has only been tested with the MAX6650 chip. It should
  13  * also work with the MAX6651. It does not distinguish max6650 and max6651
  14  * chips.
  15  *
  16  * The datasheet was last seen at:
  17  *
  18  *        http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/slab.h>
  24 #include <linux/jiffies.h>
  25 #include <linux/i2c.h>
  26 #include <linux/hwmon.h>
  27 #include <linux/hwmon-sysfs.h>
  28 #include <linux/err.h>
  29 #include <linux/of_device.h>
  30 #include <linux/thermal.h>
  31
  32 /*
  33  * Insmod parameters
  34  */
  35
  36 /* fan_voltage: 5=5V fan, 12=12V fan, 0=don't change */
  37 static int fan_voltage;
  38 /* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */
  39 static int prescaler;
  40 /* clock: The clock frequency of the chip (max6651 can be clocked externally) */
  41 static int clock = 254000;
  42
  43 module_param(fan_voltage, int, 0444);
  44 module_param(prescaler, int, 0444);
  45 module_param(clock, int, 0444);
  46
  47 /*
  48  * MAX 6650/6651 registers
  49  */
  50
  51 #define MAX6650_REG_SPEED       0x00
  52 #define MAX6650_REG_CONFIG      0x02
  53 #define MAX6650_REG_GPIO_DEF    0x04
  54 #define MAX6650_REG_DAC         0x06
  55 #define MAX6650_REG_ALARM_EN    0x08
  56 #define MAX6650_REG_ALARM       0x0A
  57 #define MAX6650_REG_TACH0       0x0C
  58 #define MAX6650_REG_TACH1       0x0E
  59 #define MAX6650_REG_TACH2       0x10
  60 #define MAX6650_REG_TACH3       0x12
  61 #define MAX6650_REG_GPIO_STAT   0x14
  62 #define MAX6650_REG_COUNT       0x16
  63
  64 /*
  65  * Config register bits
  66  */
  67
  68 #define MAX6650_CFG_V12                 0x08
  69 #define MAX6650_CFG_PRESCALER_MASK      0x07
  70 #define MAX6650_CFG_PRESCALER_2         0x01
  71 #define MAX6650_CFG_PRESCALER_4         0x02
  72 #define MAX6650_CFG_PRESCALER_8         0x03
  73 #define MAX6650_CFG_PRESCALER_16        0x04
  74 #define MAX6650_CFG_MODE_MASK           0x30
  75 #define MAX6650_CFG_MODE_ON             0x00
  76 #define MAX6650_CFG_MODE_OFF            0x10
  77 #define MAX6650_CFG_MODE_CLOSED_LOOP    0x20
  78 #define MAX6650_CFG_MODE_OPEN_LOOP      0x30
  79 #define MAX6650_COUNT_MASK              0x03
  80
  81 /*
  82  * Alarm status register bits
  83  */
  84
  85 #define MAX6650_ALRM_MAX        0x01
  86 #define MAX6650_ALRM_MIN        0x02
  87 #define MAX6650_ALRM_TACH       0x04
  88 #define MAX6650_ALRM_GPIO1      0x08
  89 #define MAX6650_ALRM_GPIO2      0x10
  90
  91 /* Minimum and maximum values of the FAN-RPM */
  92 #define FAN_RPM_MIN 240
  93 #define FAN_RPM_MAX 30000
  94
  95 #define DIV_FROM_REG(reg)       (1 << ((reg) & 7))
  96 #define DAC_LIMIT(v12)          ((v12) ? 180 : 76)
  97
  98 /*
  99  * Client data (each client gets its own)
 100  */
 101
 102 struct max6650_data {
 103         struct i2c_client *client;
 104         struct mutex update_lock; /* protect alarm register updates */
 105         int nr_fans;
 106         bool valid; /* false until following fields are valid */
 107         unsigned long last_updated; /* in jiffies */
 108
 109         /* register values */
 110         u8 speed;
 111         u8 config;
 112         u8 tach[4];
 113         u8 count;
 114         u8 dac;
 115         u8 alarm;
 116         u8 alarm_en;
 117         unsigned long cooling_dev_state;
 118 };
 119
 120 static const u8 tach_reg[] = {
 121         MAX6650_REG_TACH0,
 122         MAX6650_REG_TACH1,
 123         MAX6650_REG_TACH2,
 124         MAX6650_REG_TACH3,
 125 };
 126
 127 static const struct of_device_id __maybe_unused max6650_dt_match[] = {
 128         {
 129                 .compatible = "maxim,max6650",
 130                 .data = (void *)1
 131         },
 132         {
 133                 .compatible = "maxim,max6651",
 134                 .data = (void *)4
 135         },
 136         { },
 137 };
 138 MODULE_DEVICE_TABLE(of, max6650_dt_match);
 139
 140 static int dac_to_pwm(int dac, bool v12)
 141 {
 142         /*
 143          * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans.
 144          * Lower DAC values mean higher speeds.
 145          */
 146         return clamp_val(255 - (255 * dac) / DAC_LIMIT(v12), 0, 255);
 147 }
 148
 149 static u8 pwm_to_dac(unsigned int pwm, bool v12)
 150 {
 151         int limit = DAC_LIMIT(v12);
 152
 153         return limit - (limit * pwm) / 255;
 154 }
 155
 156 static struct max6650_data *max6650_update_device(struct device *dev)
 157 {
 158         struct max6650_data *data = dev_get_drvdata(dev);
 159         struct i2c_client *client = data->client;
 160         int reg, err = 0;
 161         int i;
 162
 163         mutex_lock(&data->update_lock);
 164
 165         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
 166                 for (i = 0; i < data->nr_fans; i++) {
 167                         reg = i2c_smbus_read_byte_data(client, tach_reg[i]);
 168                         if (reg < 0) {
 169                                 err = reg;
 170                                 goto error;
 171                         }
 172                         data->tach[i] = reg;
 173                 }
 174
 175                 /*
 176                  * Alarms are cleared on read in case the condition that
 177                  * caused the alarm is removed. Keep the value latched here
 178                  * for providing the register through different alarm files.
 179                  */
 180                 reg = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM);
 181                 if (reg < 0) {
 182                         err = reg;
 183                         goto error;
 184                 }
 185                 data->alarm |= reg;
 186                 data->last_updated = jiffies;
 187                 data->valid = true;
 188         }
 189
 190 error:
 191         mutex_unlock(&data->update_lock);
 192         if (err)
 193                 data = ERR_PTR(err);
 194         return data;
 195 }
 196
 197 /*
 198  * Change the operating mode of the chip (if needed).
 199  * mode is one of the MAX6650_CFG_MODE_* values.
 200  */
 201 static int max6650_set_operating_mode(struct max6650_data *data, u8 mode)
 202 {
 203         int result;
 204         u8 config = data->config;
 205
 206         if (mode == (config & MAX6650_CFG_MODE_MASK))
 207                 return 0;
 208
 209         config = (config & ~MAX6650_CFG_MODE_MASK) | mode;
 210
 211         result = i2c_smbus_write_byte_data(data->client, MAX6650_REG_CONFIG,
 212                                            config);
 213         if (result < 0)
 214                 return result;
 215
 216         data->config = config;
 217
 218         return 0;
 219 }
 220
 221 /*
 222  * Set the fan speed to the specified RPM (or read back the RPM setting).
 223  * This works in closed loop mode only. Use pwm1 for open loop speed setting.
 224  *
 225  * The MAX6650/1 will automatically control fan speed when in closed loop
 226  * mode.
 227  *
 228  * Assumptions:
 229  *
 230  * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use
 231  *    the clock module parameter if you need to fine tune this.
 232  *
 233  * 2) The prescaler (low three bits of the config register) has already
 234  *    been set to an appropriate value. Use the prescaler module parameter
 235  *    if your BIOS doesn't initialize the chip properly.
 236  *
 237  * The relevant equations are given on pages 21 and 22 of the datasheet.
 238  *
 239  * From the datasheet, the relevant equation when in regulation is:
 240  *
 241  *    [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE
 242  *
 243  * where:
 244  *
 245  *    fCLK is the oscillator frequency (either the 254kHz internal
 246  *         oscillator or the externally applied clock)
 247  *
 248  *    KTACH is the value in the speed register
 249  *
 250  *    FanSpeed is the speed of the fan in rps
 251  *
 252  *    KSCALE is the prescaler value (1, 2, 4, 8, or 16)
 253  *
 254  * When reading, we need to solve for FanSpeed. When writing, we need to
 255  * solve for KTACH.
 256  *
 257  * Note: this tachometer is completely separate from the tachometers
 258  * used to measure the fan speeds. Only one fan's speed (fan1) is
 259  * controlled.
 260  */
 261
 262 static int max6650_set_target(struct max6650_data *data, unsigned long rpm)
 263 {
 264         int kscale, ktach;
 265
 266         if (rpm == 0)
 267                 return max6650_set_operating_mode(data, MAX6650_CFG_MODE_OFF);
 268
 269         rpm = clamp_val(rpm, FAN_RPM_MIN, FAN_RPM_MAX);
 270
 271         /*
 272          * Divide the required speed by 60 to get from rpm to rps, then
 273          * use the datasheet equation:
 274          *
 275          *     KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1
 276          */
 277
 278         kscale = DIV_FROM_REG(data->config);
 279         ktach = ((clock * kscale) / (256 * rpm / 60)) - 1;
 280         if (ktach < 0)
 281                 ktach = 0;
 282         if (ktach > 255)
 283                 ktach = 255;
 284         data->speed = ktach;
 285
 286         return i2c_smbus_write_byte_data(data->client, MAX6650_REG_SPEED,
 287                                          data->speed);
 288 }
 289
 290 /*
 291  * Get gpio alarm status:
 292  * Possible values:
 293  * 0 = no alarm
 294  * 1 = alarm
 295  */
 296
 297 static ssize_t alarm_show(struct device *dev,
 298                           struct device_attribute *devattr, char *buf)
 299 {
 300         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 301         struct max6650_data *data = max6650_update_device(dev);
 302         bool alarm;
 303
 304         if (IS_ERR(data))
 305                 return PTR_ERR(data);
 306
 307         alarm = data->alarm & attr->index;
 308         if (alarm) {
 309                 mutex_lock(&data->update_lock);
 310                 data->alarm &= ~attr->index;
 311                 data->valid = false;
 312                 mutex_unlock(&data->update_lock);
 313         }
 314
 315         return sprintf(buf, "%d\n", alarm);
 316 }
 317
 318 static SENSOR_DEVICE_ATTR_RO(gpio1_alarm, alarm, MAX6650_ALRM_GPIO1);
 319 static SENSOR_DEVICE_ATTR_RO(gpio2_alarm, alarm, MAX6650_ALRM_GPIO2);
 320
 321 static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a,
 322                                      int n)
 323 {
 324         struct device *dev = container_of(kobj, struct device, kobj);
 325         struct max6650_data *data = dev_get_drvdata(dev);
 326         struct device_attribute *devattr;
 327
 328         /*
 329          * Hide the alarms that have not been enabled by the firmware
 330          */
 331
 332         devattr = container_of(a, struct device_attribute, attr);
 333         if (devattr == &sensor_dev_attr_gpio1_alarm.dev_attr ||
 334             devattr == &sensor_dev_attr_gpio2_alarm.dev_attr) {
 335                 if (!(data->alarm_en & to_sensor_dev_attr(devattr)->index))
 336                         return 0;
 337         }
 338
 339         return a->mode;
 340 }
 341
 342 static struct attribute *max6650_attrs[] = {
 343         &sensor_dev_attr_gpio1_alarm.dev_attr.attr,
 344         &sensor_dev_attr_gpio2_alarm.dev_attr.attr,
 345         NULL
 346 };
 347
 348 static const struct attribute_group max6650_group = {
 349         .attrs = max6650_attrs,
 350         .is_visible = max6650_attrs_visible,
 351 };
 352
 353 static const struct attribute_group *max6650_groups[] = {
 354         &max6650_group,
 355         NULL
 356 };
 357
 358 static int max6650_init_client(struct max6650_data *data,
 359                                struct i2c_client *client)
 360 {
 361         struct device *dev = &client->dev;
 362         int reg;
 363         int err;
 364         u32 voltage;
 365         u32 prescale;
 366         u32 target_rpm;
 367
 368         if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt",
 369                                  &voltage))
 370                 voltage = fan_voltage;
 371         else
 372                 voltage /= 1000000; /* Microvolts to volts */
 373         if (of_property_read_u32(dev->of_node, "maxim,fan-prescale",
 374                                  &prescale))
 375                 prescale = prescaler;
 376
 377         reg = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
 378         if (reg < 0) {
 379                 dev_err(dev, "Error reading config register, aborting.\n");
 380                 return reg;
 381         }
 382
 383         switch (voltage) {
 384         case 0:
 385                 break;
 386         case 5:
 387                 reg &= ~MAX6650_CFG_V12;
 388                 break;
 389         case 12:
 390                 reg |= MAX6650_CFG_V12;
 391                 break;
 392         default:
 393                 dev_err(dev, "illegal value for fan_voltage (%d)\n", voltage);
 394         }
 395
 396         switch (prescale) {
 397         case 0:
 398                 break;
 399         case 1:
 400                 reg &= ~MAX6650_CFG_PRESCALER_MASK;
 401                 break;
 402         case 2:
 403                 reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
 404                          | MAX6650_CFG_PRESCALER_2;
 405                 break;
 406         case  4:
 407                 reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
 408                          | MAX6650_CFG_PRESCALER_4;
 409                 break;
 410         case  8:
 411                 reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
 412                          | MAX6650_CFG_PRESCALER_8;
 413                 break;
 414         case 16:
 415                 reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
 416                          | MAX6650_CFG_PRESCALER_16;
 417                 break;
 418         default:
 419                 dev_err(dev, "illegal value for prescaler (%d)\n", prescale);
 420         }
 421
 422         dev_info(dev, "Fan voltage: %dV, prescaler: %d.\n",
 423                  (reg & MAX6650_CFG_V12) ? 12 : 5,
 424                  1 << (reg & MAX6650_CFG_PRESCALER_MASK));
 425
 426         err = i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, reg);
 427         if (err) {
 428                 dev_err(dev, "Config write error, aborting.\n");
 429                 return err;
 430         }
 431         data->config = reg;
 432
 433         reg = i2c_smbus_read_byte_data(client, MAX6650_REG_SPEED);
 434         if (reg < 0) {
 435                 dev_err(dev, "Failed to read speed register, aborting.\n");
 436                 return reg;
 437         }
 438         data->speed = reg;
 439
 440         reg = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC);
 441         if (reg < 0) {
 442                 dev_err(dev, "Failed to read DAC register, aborting.\n");
 443                 return reg;
 444         }
 445         data->dac = reg;
 446
 447         reg = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT);
 448         if (reg < 0) {
 449                 dev_err(dev, "Failed to read count register, aborting.\n");
 450                 return reg;
 451         }
 452         data->count = reg;
 453
 454         reg = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN);
 455         if (reg < 0) {
 456                 dev_err(dev, "Failed to read alarm configuration, aborting.\n");
 457                 return reg;
 458         }
 459         data->alarm_en = reg;
 460
 461         if (!of_property_read_u32(client->dev.of_node, "maxim,fan-target-rpm",
 462                                   &target_rpm)) {
 463                 max6650_set_target(data, target_rpm);
 464                 max6650_set_operating_mode(data, MAX6650_CFG_MODE_CLOSED_LOOP);
 465         }
 466
 467         return 0;
 468 }
 469
 470 static int max6650_get_max_state(struct thermal_cooling_device *cdev,
 471                                  unsigned long *state)
 472 {
 473         *state = 255;
 474
 475         return 0;
 476 }
 477
 478 static int max6650_get_cur_state(struct thermal_cooling_device *cdev,
 479                                  unsigned long *state)
 480 {
 481         struct max6650_data *data = cdev->devdata;
 482
 483         *state = data->cooling_dev_state;
 484
 485         return 0;
 486 }
 487
 488 static int max6650_set_cur_state(struct thermal_cooling_device *cdev,
 489                                  unsigned long state)
 490 {
 491         struct max6650_data *data = cdev->devdata;
 492         struct i2c_client *client = data->client;
 493         int err;
 494
 495         state = clamp_val(state, 0, 255);
 496
 497         mutex_lock(&data->update_lock);
 498
 499         data->dac = pwm_to_dac(state, data->config & MAX6650_CFG_V12);
 500         err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
 501         if (!err) {
 502                 max6650_set_operating_mode(data, state ?
 503                                            MAX6650_CFG_MODE_OPEN_LOOP :
 504                                            MAX6650_CFG_MODE_OFF);
 505                 data->cooling_dev_state = state;
 506         }
 507
 508         mutex_unlock(&data->update_lock);
 509
 510         return err;
 511 }
 512
 513 static const struct thermal_cooling_device_ops max6650_cooling_ops = {
 514         .get_max_state = max6650_get_max_state,
 515         .get_cur_state = max6650_get_cur_state,
 516         .set_cur_state = max6650_set_cur_state,
 517 };
 518
 519 static int max6650_read(struct device *dev, enum hwmon_sensor_types type,
 520                         u32 attr, int channel, long *val)
 521 {
 522         struct max6650_data *data = max6650_update_device(dev);
 523         int mode;
 524
 525         if (IS_ERR(data))
 526                 return PTR_ERR(data);
 527
 528         switch (type) {
 529         case hwmon_pwm:
 530                 switch (attr) {
 531                 case hwmon_pwm_input:
 532                         *val = dac_to_pwm(data->dac,
 533                                           data->config & MAX6650_CFG_V12);
 534                         break;
 535                 case hwmon_pwm_enable:
 536                         /*
 537                          * Possible values:
 538                          * 0 = Fan always on
 539                          * 1 = Open loop, Voltage is set according to speed,
 540                          *     not regulated.
 541                          * 2 = Closed loop, RPM for all fans regulated by fan1
 542                          *     tachometer
 543                          * 3 = Fan off
 544                          */
 545                         mode = (data->config & MAX6650_CFG_MODE_MASK) >> 4;
 546                         *val = (4 - mode) & 3; /* {0 1 2 3} -> {0 3 2 1} */
 547                         break;
 548                 default:
 549                         return -EOPNOTSUPP;
 550                 }
 551                 break;
 552         case hwmon_fan:
 553                 switch (attr) {
 554                 case hwmon_fan_input:
 555                         /*
 556                          * Calculation details:
 557                          *
 558                          * Each tachometer counts over an interval given by the
 559                          * "count" register (0.25, 0.5, 1 or 2 seconds).
 560                          * The driver assumes that the fans produce two pulses
 561                          * per revolution (this seems to be the most common).
 562                          */
 563                         *val = DIV_ROUND_CLOSEST(data->tach[channel] * 120,
 564                                                  DIV_FROM_REG(data->count));
 565                         break;
 566                 case hwmon_fan_div:
 567                         *val = DIV_FROM_REG(data->count);
 568                         break;
 569                 case hwmon_fan_target:
 570                         /*
 571                          * Use the datasheet equation:
 572                          *    FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)]
 573                          * then multiply by 60 to give rpm.
 574                          */
 575                         *val = 60 * DIV_FROM_REG(data->config) * clock /
 576                                 (256 * (data->speed + 1));
 577                         break;
 578                 case hwmon_fan_min_alarm:
 579                         *val = !!(data->alarm & MAX6650_ALRM_MIN);
 580                         data->alarm &= ~MAX6650_ALRM_MIN;
 581                         data->valid = false;
 582                         break;
 583                 case hwmon_fan_max_alarm:
 584                         *val = !!(data->alarm & MAX6650_ALRM_MAX);
 585                         data->alarm &= ~MAX6650_ALRM_MAX;
 586                         data->valid = false;
 587                         break;
 588                 case hwmon_fan_fault:
 589                         *val = !!(data->alarm & MAX6650_ALRM_TACH);
 590                         data->alarm &= ~MAX6650_ALRM_TACH;
 591                         data->valid = false;
 592                         break;
 593                 default:
 594                         return -EOPNOTSUPP;
 595                 }
 596                 break;
 597         default:
 598                 return -EOPNOTSUPP;
 599         }
 600         return 0;
 601 }
 602
 603 static const u8 max6650_pwm_modes[] = {
 604         MAX6650_CFG_MODE_ON,
 605         MAX6650_CFG_MODE_OPEN_LOOP,
 606         MAX6650_CFG_MODE_CLOSED_LOOP,
 607         MAX6650_CFG_MODE_OFF,
 608 };
 609
 610 static int max6650_write(struct device *dev, enum hwmon_sensor_types type,
 611                          u32 attr, int channel, long val)
 612 {
 613         struct max6650_data *data = dev_get_drvdata(dev);
 614         int ret = 0;
 615         u8 reg;
 616
 617         mutex_lock(&data->update_lock);
 618
 619         switch (type) {
 620         case hwmon_pwm:
 621                 switch (attr) {
 622                 case hwmon_pwm_input:
 623                         reg = pwm_to_dac(clamp_val(val, 0, 255),
 624                                          data->config & MAX6650_CFG_V12);
 625                         ret = i2c_smbus_write_byte_data(data->client,
 626                                                         MAX6650_REG_DAC, reg);
 627                         if (ret)
 628                                 break;
 629                         data->dac = reg;
 630                         break;
 631                 case hwmon_pwm_enable:
 632                         if (val < 0 || val >= ARRAY_SIZE(max6650_pwm_modes)) {
 633                                 ret = -EINVAL;
 634                                 break;
 635                         }
 636                         ret = max6650_set_operating_mode(data,
 637                                                 max6650_pwm_modes[val]);
 638                         break;
 639                 default:
 640                         ret = -EOPNOTSUPP;
 641                         break;
 642                 }
 643                 break;
 644         case hwmon_fan:
 645                 switch (attr) {
 646                 case hwmon_fan_div:
 647                         switch (val) {
 648                         case 1:
 649                                 reg = 0;
 650                                 break;
 651                         case 2:
 652                                 reg = 1;
 653                                 break;
 654                         case 4:
 655                                 reg = 2;
 656                                 break;
 657                         case 8:
 658                                 reg = 3;
 659                                 break;
 660                         default:
 661                                 ret = -EINVAL;
 662                                 goto error;
 663                         }
 664                         ret = i2c_smbus_write_byte_data(data->client,
 665                                                         MAX6650_REG_COUNT, reg);
 666                         if (ret)
 667                                 break;
 668                         data->count = reg;
 669                         break;
 670                 case hwmon_fan_target:
 671                         if (val < 0) {
 672                                 ret = -EINVAL;
 673                                 break;
 674                         }
 675                         ret = max6650_set_target(data, val);
 676                         break;
 677                 default:
 678                         ret = -EOPNOTSUPP;
 679                         break;
 680                 }
 681                 break;
 682         default:
 683                 ret = -EOPNOTSUPP;
 684                 break;
 685         }
 686
 687 error:
 688         mutex_unlock(&data->update_lock);
 689         return ret;
 690 }
 691
 692 static umode_t max6650_is_visible(const void *_data,
 693                                   enum hwmon_sensor_types type, u32 attr,
 694                                   int channel)
 695 {
 696         const struct max6650_data *data = _data;
 697
 698         if (channel && (channel >= data->nr_fans || type != hwmon_fan))
 699                 return 0;
 700
 701         switch (type) {
 702         case hwmon_fan:
 703                 switch (attr) {
 704                 case hwmon_fan_input:
 705                         return 0444;
 706                 case hwmon_fan_target:
 707                 case hwmon_fan_div:
 708                         return 0644;
 709                 case hwmon_fan_min_alarm:
 710                         if (data->alarm_en & MAX6650_ALRM_MIN)
 711                                 return 0444;
 712                         break;
 713                 case hwmon_fan_max_alarm:
 714                         if (data->alarm_en & MAX6650_ALRM_MAX)
 715                                 return 0444;
 716                         break;
 717                 case hwmon_fan_fault:
 718                         if (data->alarm_en & MAX6650_ALRM_TACH)
 719                                 return 0444;
 720                         break;
 721                 default:
 722                         break;
 723                 }
 724                 break;
 725         case hwmon_pwm:
 726                 switch (attr) {
 727                 case hwmon_pwm_input:
 728                 case hwmon_pwm_enable:
 729                         return 0644;
 730                 default:
 731                         break;
 732                 }
 733                 break;
 734         default:
 735                 break;
 736         }
 737         return 0;
 738 }
 739
 740 static const struct hwmon_channel_info *max6650_info[] = {
 741         HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_DIV |
 742                            HWMON_F_MIN_ALARM | HWMON_F_MAX_ALARM |
 743                            HWMON_F_FAULT,
 744                            HWMON_F_INPUT, HWMON_F_INPUT, HWMON_F_INPUT),
 745         HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
 746         NULL
 747 };
 748
 749 static const struct hwmon_ops max6650_hwmon_ops = {
 750         .read = max6650_read,
 751         .write = max6650_write,
 752         .is_visible = max6650_is_visible,
 753 };
 754
 755 static const struct hwmon_chip_info max6650_chip_info = {
 756         .ops = &max6650_hwmon_ops,
 757         .info = max6650_info,
 758 };
 759
 760 static const struct i2c_device_id max6650_id[];
 761
 762 static int max6650_probe(struct i2c_client *client)
 763 {
 764         struct thermal_cooling_device *cooling_dev;
 765         struct device *dev = &client->dev;
 766         const struct of_device_id *of_id =
 767                 of_match_device(of_match_ptr(max6650_dt_match), dev);
 768         struct max6650_data *data;
 769         struct device *hwmon_dev;
 770         int err;
 771
 772         data = devm_kzalloc(dev, sizeof(struct max6650_data), GFP_KERNEL);
 773         if (!data)
 774                 return -ENOMEM;
 775
 776         data->client = client;
 777         i2c_set_clientdata(client, data);
 778         mutex_init(&data->update_lock);
 779         data->nr_fans = of_id ? (int)(uintptr_t)of_id->data :
 780                                 i2c_match_id(max6650_id, client)->driver_data;
 781
 782         /*
 783          * Initialize the max6650 chip
 784          */
 785         err = max6650_init_client(data, client);
 786         if (err)
 787                 return err;
 788
 789         hwmon_dev = devm_hwmon_device_register_with_info(dev,
 790                                                          client->name, data,
 791                                                          &max6650_chip_info,
 792                                                          max6650_groups);
 793         err = PTR_ERR_OR_ZERO(hwmon_dev);
 794         if (err)
 795                 return err;
 796
 797         if (IS_ENABLED(CONFIG_THERMAL)) {
 798                 cooling_dev = devm_thermal_of_cooling_device_register(dev,
 799                                                 dev->of_node, client->name,
 800                                                 data, &max6650_cooling_ops);
 801                 if (IS_ERR(cooling_dev)) {
 802                         dev_warn(dev, "thermal cooling device register failed: %ld\n",
 803                                  PTR_ERR(cooling_dev));
 804                 }
 805         }
 806
 807         return 0;
 808 }
 809
 810 static const struct i2c_device_id max6650_id[] = {
 811         { "max6650", 1 },
 812         { "max6651", 4 },
 813         { }
 814 };
 815 MODULE_DEVICE_TABLE(i2c, max6650_id);
 816
 817 static struct i2c_driver max6650_driver = {
 818         .driver = {
 819                 .name   = "max6650",
 820                 .of_match_table = of_match_ptr(max6650_dt_match),
 821         },
 822         .probe_new      = max6650_probe,
 823         .id_table       = max6650_id,
 824 };
 825
 826 module_i2c_driver(max6650_driver);
 827
 828 MODULE_AUTHOR("Hans J. Koch");
 829 MODULE_DESCRIPTION("MAX6650 sensor driver");
 830 MODULE_LICENSE("GPL");