linux/drivers/hwmon/max6650.c
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   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 */
  37static int fan_voltage;
  38/* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */
  39static int prescaler;
  40/* clock: The clock frequency of the chip (max6651 can be clocked externally) */
  41static int clock = 254000;
  42
  43module_param(fan_voltage, int, 0444);
  44module_param(prescaler, int, 0444);
  45module_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
 102struct 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
 120static const u8 tach_reg[] = {
 121        MAX6650_REG_TACH0,
 122        MAX6650_REG_TACH1,
 123        MAX6650_REG_TACH2,
 124        MAX6650_REG_TACH3,
 125};
 126
 127static 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};
 138MODULE_DEVICE_TABLE(of, max6650_dt_match);
 139
 140static 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
 149static 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
 156static 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
 190error:
 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 */
 201static 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
 262static 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
 297static 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
 318static SENSOR_DEVICE_ATTR_RO(gpio1_alarm, alarm, MAX6650_ALRM_GPIO1);
 319static SENSOR_DEVICE_ATTR_RO(gpio2_alarm, alarm, MAX6650_ALRM_GPIO2);
 320
 321static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a,
 322                                     int n)
 323{
 324        struct device *dev = kobj_to_dev(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
 342static 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
 348static const struct attribute_group max6650_group = {
 349        .attrs = max6650_attrs,
 350        .is_visible = max6650_attrs_visible,
 351};
 352
 353static const struct attribute_group *max6650_groups[] = {
 354        &max6650_group,
 355        NULL
 356};
 357
 358static 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
 470static int max6650_get_max_state(struct thermal_cooling_device *cdev,
 471                                 unsigned long *state)
 472{
 473        *state = 255;
 474
 475        return 0;
 476}
 477
 478static 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
 488static 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
 513static 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
 519static 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
 603static 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
 610static 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
 687error:
 688        mutex_unlock(&data->update_lock);
 689        return ret;
 690}
 691
 692static 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
 740static 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
 749static const struct hwmon_ops max6650_hwmon_ops = {
 750        .read = max6650_read,
 751        .write = max6650_write,
 752        .is_visible = max6650_is_visible,
 753};
 754
 755static const struct hwmon_chip_info max6650_chip_info = {
 756        .ops = &max6650_hwmon_ops,
 757        .info = max6650_info,
 758};
 759
 760static const struct i2c_device_id max6650_id[];
 761
 762static 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
 810static const struct i2c_device_id max6650_id[] = {
 811        { "max6650", 1 },
 812        { "max6651", 4 },
 813        { }
 814};
 815MODULE_DEVICE_TABLE(i2c, max6650_id);
 816
 817static 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
 826module_i2c_driver(max6650_driver);
 827
 828MODULE_AUTHOR("Hans J. Koch");
 829MODULE_DESCRIPTION("MAX6650 sensor driver");
 830MODULE_LICENSE("GPL");
 831