linux/drivers/hwmon/max6639.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * max6639.c - Support for Maxim MAX6639
   4 *
   5 * 2-Channel Temperature Monitor with Dual PWM Fan-Speed Controller
   6 *
   7 * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
   8 *
   9 * based on the initial MAX6639 support from semptian.net
  10 * by He Changqing <hechangqing@semptian.com>
  11 */
  12
  13#include <linux/module.h>
  14#include <linux/init.h>
  15#include <linux/slab.h>
  16#include <linux/jiffies.h>
  17#include <linux/i2c.h>
  18#include <linux/hwmon.h>
  19#include <linux/hwmon-sysfs.h>
  20#include <linux/err.h>
  21#include <linux/mutex.h>
  22#include <linux/platform_data/max6639.h>
  23
  24/* Addresses to scan */
  25static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
  26
  27/* The MAX6639 registers, valid channel numbers: 0, 1 */
  28#define MAX6639_REG_TEMP(ch)                    (0x00 + (ch))
  29#define MAX6639_REG_STATUS                      0x02
  30#define MAX6639_REG_OUTPUT_MASK                 0x03
  31#define MAX6639_REG_GCONFIG                     0x04
  32#define MAX6639_REG_TEMP_EXT(ch)                (0x05 + (ch))
  33#define MAX6639_REG_ALERT_LIMIT(ch)             (0x08 + (ch))
  34#define MAX6639_REG_OT_LIMIT(ch)                (0x0A + (ch))
  35#define MAX6639_REG_THERM_LIMIT(ch)             (0x0C + (ch))
  36#define MAX6639_REG_FAN_CONFIG1(ch)             (0x10 + (ch) * 4)
  37#define MAX6639_REG_FAN_CONFIG2a(ch)            (0x11 + (ch) * 4)
  38#define MAX6639_REG_FAN_CONFIG2b(ch)            (0x12 + (ch) * 4)
  39#define MAX6639_REG_FAN_CONFIG3(ch)             (0x13 + (ch) * 4)
  40#define MAX6639_REG_FAN_CNT(ch)                 (0x20 + (ch))
  41#define MAX6639_REG_TARGET_CNT(ch)              (0x22 + (ch))
  42#define MAX6639_REG_FAN_PPR(ch)                 (0x24 + (ch))
  43#define MAX6639_REG_TARGTDUTY(ch)               (0x26 + (ch))
  44#define MAX6639_REG_FAN_START_TEMP(ch)          (0x28 + (ch))
  45#define MAX6639_REG_DEVID                       0x3D
  46#define MAX6639_REG_MANUID                      0x3E
  47#define MAX6639_REG_DEVREV                      0x3F
  48
  49/* Register bits */
  50#define MAX6639_GCONFIG_STANDBY                 0x80
  51#define MAX6639_GCONFIG_POR                     0x40
  52#define MAX6639_GCONFIG_DISABLE_TIMEOUT         0x20
  53#define MAX6639_GCONFIG_CH2_LOCAL               0x10
  54#define MAX6639_GCONFIG_PWM_FREQ_HI             0x08
  55
  56#define MAX6639_FAN_CONFIG1_PWM                 0x80
  57
  58#define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED    0x40
  59
  60static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
  61
  62#define FAN_FROM_REG(val, rpm_range)    ((val) == 0 || (val) == 255 ? \
  63                                0 : (rpm_ranges[rpm_range] * 30) / (val))
  64#define TEMP_LIMIT_TO_REG(val)  clamp_val((val) / 1000, 0, 255)
  65
  66/*
  67 * Client data (each client gets its own)
  68 */
  69struct max6639_data {
  70        struct i2c_client *client;
  71        struct mutex update_lock;
  72        bool valid;             /* true if following fields are valid */
  73        unsigned long last_updated;     /* In jiffies */
  74
  75        /* Register values sampled regularly */
  76        u16 temp[2];            /* Temperature, in 1/8 C, 0..255 C */
  77        bool temp_fault[2];     /* Detected temperature diode failure */
  78        u8 fan[2];              /* Register value: TACH count for fans >=30 */
  79        u8 status;              /* Detected channel alarms and fan failures */
  80
  81        /* Register values only written to */
  82        u8 pwm[2];              /* Register value: Duty cycle 0..120 */
  83        u8 temp_therm[2];       /* THERM Temperature, 0..255 C (->_max) */
  84        u8 temp_alert[2];       /* ALERT Temperature, 0..255 C (->_crit) */
  85        u8 temp_ot[2];          /* OT Temperature, 0..255 C (->_emergency) */
  86
  87        /* Register values initialized only once */
  88        u8 ppr;                 /* Pulses per rotation 0..3 for 1..4 ppr */
  89        u8 rpm_range;           /* Index in above rpm_ranges table */
  90
  91        /* Optional regulator for FAN supply */
  92        struct regulator *reg;
  93};
  94
  95static struct max6639_data *max6639_update_device(struct device *dev)
  96{
  97        struct max6639_data *data = dev_get_drvdata(dev);
  98        struct i2c_client *client = data->client;
  99        struct max6639_data *ret = data;
 100        int i;
 101        int status_reg;
 102
 103        mutex_lock(&data->update_lock);
 104
 105        if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
 106                int res;
 107
 108                dev_dbg(&client->dev, "Starting max6639 update\n");
 109
 110                status_reg = i2c_smbus_read_byte_data(client,
 111                                                      MAX6639_REG_STATUS);
 112                if (status_reg < 0) {
 113                        ret = ERR_PTR(status_reg);
 114                        goto abort;
 115                }
 116
 117                data->status = status_reg;
 118
 119                for (i = 0; i < 2; i++) {
 120                        res = i2c_smbus_read_byte_data(client,
 121                                        MAX6639_REG_FAN_CNT(i));
 122                        if (res < 0) {
 123                                ret = ERR_PTR(res);
 124                                goto abort;
 125                        }
 126                        data->fan[i] = res;
 127
 128                        res = i2c_smbus_read_byte_data(client,
 129                                        MAX6639_REG_TEMP_EXT(i));
 130                        if (res < 0) {
 131                                ret = ERR_PTR(res);
 132                                goto abort;
 133                        }
 134                        data->temp[i] = res >> 5;
 135                        data->temp_fault[i] = res & 0x01;
 136
 137                        res = i2c_smbus_read_byte_data(client,
 138                                        MAX6639_REG_TEMP(i));
 139                        if (res < 0) {
 140                                ret = ERR_PTR(res);
 141                                goto abort;
 142                        }
 143                        data->temp[i] |= res << 3;
 144                }
 145
 146                data->last_updated = jiffies;
 147                data->valid = true;
 148        }
 149abort:
 150        mutex_unlock(&data->update_lock);
 151
 152        return ret;
 153}
 154
 155static ssize_t temp_input_show(struct device *dev,
 156                               struct device_attribute *dev_attr, char *buf)
 157{
 158        long temp;
 159        struct max6639_data *data = max6639_update_device(dev);
 160        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 161
 162        if (IS_ERR(data))
 163                return PTR_ERR(data);
 164
 165        temp = data->temp[attr->index] * 125;
 166        return sprintf(buf, "%ld\n", temp);
 167}
 168
 169static ssize_t temp_fault_show(struct device *dev,
 170                               struct device_attribute *dev_attr, char *buf)
 171{
 172        struct max6639_data *data = max6639_update_device(dev);
 173        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 174
 175        if (IS_ERR(data))
 176                return PTR_ERR(data);
 177
 178        return sprintf(buf, "%d\n", data->temp_fault[attr->index]);
 179}
 180
 181static ssize_t temp_max_show(struct device *dev,
 182                             struct device_attribute *dev_attr, char *buf)
 183{
 184        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 185        struct max6639_data *data = dev_get_drvdata(dev);
 186
 187        return sprintf(buf, "%d\n", (data->temp_therm[attr->index] * 1000));
 188}
 189
 190static ssize_t temp_max_store(struct device *dev,
 191                              struct device_attribute *dev_attr,
 192                              const char *buf, size_t count)
 193{
 194        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 195        struct max6639_data *data = dev_get_drvdata(dev);
 196        struct i2c_client *client = data->client;
 197        unsigned long val;
 198        int res;
 199
 200        res = kstrtoul(buf, 10, &val);
 201        if (res)
 202                return res;
 203
 204        mutex_lock(&data->update_lock);
 205        data->temp_therm[attr->index] = TEMP_LIMIT_TO_REG(val);
 206        i2c_smbus_write_byte_data(client,
 207                                  MAX6639_REG_THERM_LIMIT(attr->index),
 208                                  data->temp_therm[attr->index]);
 209        mutex_unlock(&data->update_lock);
 210        return count;
 211}
 212
 213static ssize_t temp_crit_show(struct device *dev,
 214                              struct device_attribute *dev_attr, char *buf)
 215{
 216        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 217        struct max6639_data *data = dev_get_drvdata(dev);
 218
 219        return sprintf(buf, "%d\n", (data->temp_alert[attr->index] * 1000));
 220}
 221
 222static ssize_t temp_crit_store(struct device *dev,
 223                               struct device_attribute *dev_attr,
 224                               const char *buf, size_t count)
 225{
 226        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 227        struct max6639_data *data = dev_get_drvdata(dev);
 228        struct i2c_client *client = data->client;
 229        unsigned long val;
 230        int res;
 231
 232        res = kstrtoul(buf, 10, &val);
 233        if (res)
 234                return res;
 235
 236        mutex_lock(&data->update_lock);
 237        data->temp_alert[attr->index] = TEMP_LIMIT_TO_REG(val);
 238        i2c_smbus_write_byte_data(client,
 239                                  MAX6639_REG_ALERT_LIMIT(attr->index),
 240                                  data->temp_alert[attr->index]);
 241        mutex_unlock(&data->update_lock);
 242        return count;
 243}
 244
 245static ssize_t temp_emergency_show(struct device *dev,
 246                                   struct device_attribute *dev_attr,
 247                                   char *buf)
 248{
 249        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 250        struct max6639_data *data = dev_get_drvdata(dev);
 251
 252        return sprintf(buf, "%d\n", (data->temp_ot[attr->index] * 1000));
 253}
 254
 255static ssize_t temp_emergency_store(struct device *dev,
 256                                    struct device_attribute *dev_attr,
 257                                    const char *buf, size_t count)
 258{
 259        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 260        struct max6639_data *data = dev_get_drvdata(dev);
 261        struct i2c_client *client = data->client;
 262        unsigned long val;
 263        int res;
 264
 265        res = kstrtoul(buf, 10, &val);
 266        if (res)
 267                return res;
 268
 269        mutex_lock(&data->update_lock);
 270        data->temp_ot[attr->index] = TEMP_LIMIT_TO_REG(val);
 271        i2c_smbus_write_byte_data(client,
 272                                  MAX6639_REG_OT_LIMIT(attr->index),
 273                                  data->temp_ot[attr->index]);
 274        mutex_unlock(&data->update_lock);
 275        return count;
 276}
 277
 278static ssize_t pwm_show(struct device *dev, struct device_attribute *dev_attr,
 279                        char *buf)
 280{
 281        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 282        struct max6639_data *data = dev_get_drvdata(dev);
 283
 284        return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
 285}
 286
 287static ssize_t pwm_store(struct device *dev,
 288                         struct device_attribute *dev_attr, const char *buf,
 289                         size_t count)
 290{
 291        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 292        struct max6639_data *data = dev_get_drvdata(dev);
 293        struct i2c_client *client = data->client;
 294        unsigned long val;
 295        int res;
 296
 297        res = kstrtoul(buf, 10, &val);
 298        if (res)
 299                return res;
 300
 301        val = clamp_val(val, 0, 255);
 302
 303        mutex_lock(&data->update_lock);
 304        data->pwm[attr->index] = (u8)(val * 120 / 255);
 305        i2c_smbus_write_byte_data(client,
 306                                  MAX6639_REG_TARGTDUTY(attr->index),
 307                                  data->pwm[attr->index]);
 308        mutex_unlock(&data->update_lock);
 309        return count;
 310}
 311
 312static ssize_t fan_input_show(struct device *dev,
 313                              struct device_attribute *dev_attr, char *buf)
 314{
 315        struct max6639_data *data = max6639_update_device(dev);
 316        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 317
 318        if (IS_ERR(data))
 319                return PTR_ERR(data);
 320
 321        return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
 322                       data->rpm_range));
 323}
 324
 325static ssize_t alarm_show(struct device *dev,
 326                          struct device_attribute *dev_attr, char *buf)
 327{
 328        struct max6639_data *data = max6639_update_device(dev);
 329        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 330
 331        if (IS_ERR(data))
 332                return PTR_ERR(data);
 333
 334        return sprintf(buf, "%d\n", !!(data->status & (1 << attr->index)));
 335}
 336
 337static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);
 338static SENSOR_DEVICE_ATTR_RO(temp2_input, temp_input, 1);
 339static SENSOR_DEVICE_ATTR_RO(temp1_fault, temp_fault, 0);
 340static SENSOR_DEVICE_ATTR_RO(temp2_fault, temp_fault, 1);
 341static SENSOR_DEVICE_ATTR_RW(temp1_max, temp_max, 0);
 342static SENSOR_DEVICE_ATTR_RW(temp2_max, temp_max, 1);
 343static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp_crit, 0);
 344static SENSOR_DEVICE_ATTR_RW(temp2_crit, temp_crit, 1);
 345static SENSOR_DEVICE_ATTR_RW(temp1_emergency, temp_emergency, 0);
 346static SENSOR_DEVICE_ATTR_RW(temp2_emergency, temp_emergency, 1);
 347static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
 348static SENSOR_DEVICE_ATTR_RW(pwm2, pwm, 1);
 349static SENSOR_DEVICE_ATTR_RO(fan1_input, fan_input, 0);
 350static SENSOR_DEVICE_ATTR_RO(fan2_input, fan_input, 1);
 351static SENSOR_DEVICE_ATTR_RO(fan1_fault, alarm, 1);
 352static SENSOR_DEVICE_ATTR_RO(fan2_fault, alarm, 0);
 353static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 3);
 354static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 2);
 355static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 7);
 356static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 6);
 357static SENSOR_DEVICE_ATTR_RO(temp1_emergency_alarm, alarm, 5);
 358static SENSOR_DEVICE_ATTR_RO(temp2_emergency_alarm, alarm, 4);
 359
 360
 361static struct attribute *max6639_attrs[] = {
 362        &sensor_dev_attr_temp1_input.dev_attr.attr,
 363        &sensor_dev_attr_temp2_input.dev_attr.attr,
 364        &sensor_dev_attr_temp1_fault.dev_attr.attr,
 365        &sensor_dev_attr_temp2_fault.dev_attr.attr,
 366        &sensor_dev_attr_temp1_max.dev_attr.attr,
 367        &sensor_dev_attr_temp2_max.dev_attr.attr,
 368        &sensor_dev_attr_temp1_crit.dev_attr.attr,
 369        &sensor_dev_attr_temp2_crit.dev_attr.attr,
 370        &sensor_dev_attr_temp1_emergency.dev_attr.attr,
 371        &sensor_dev_attr_temp2_emergency.dev_attr.attr,
 372        &sensor_dev_attr_pwm1.dev_attr.attr,
 373        &sensor_dev_attr_pwm2.dev_attr.attr,
 374        &sensor_dev_attr_fan1_input.dev_attr.attr,
 375        &sensor_dev_attr_fan2_input.dev_attr.attr,
 376        &sensor_dev_attr_fan1_fault.dev_attr.attr,
 377        &sensor_dev_attr_fan2_fault.dev_attr.attr,
 378        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 379        &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 380        &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 381        &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 382        &sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
 383        &sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
 384        NULL
 385};
 386ATTRIBUTE_GROUPS(max6639);
 387
 388/*
 389 *  returns respective index in rpm_ranges table
 390 *  1 by default on invalid range
 391 */
 392static int rpm_range_to_reg(int range)
 393{
 394        int i;
 395
 396        for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
 397                if (rpm_ranges[i] == range)
 398                        return i;
 399        }
 400
 401        return 1; /* default: 4000 RPM */
 402}
 403
 404static int max6639_init_client(struct i2c_client *client,
 405                               struct max6639_data *data)
 406{
 407        struct max6639_platform_data *max6639_info =
 408                dev_get_platdata(&client->dev);
 409        int i;
 410        int rpm_range = 1; /* default: 4000 RPM */
 411        int err;
 412
 413        /* Reset chip to default values, see below for GCONFIG setup */
 414        err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
 415                                  MAX6639_GCONFIG_POR);
 416        if (err)
 417                goto exit;
 418
 419        /* Fans pulse per revolution is 2 by default */
 420        if (max6639_info && max6639_info->ppr > 0 &&
 421                        max6639_info->ppr < 5)
 422                data->ppr = max6639_info->ppr;
 423        else
 424                data->ppr = 2;
 425        data->ppr -= 1;
 426
 427        if (max6639_info)
 428                rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
 429        data->rpm_range = rpm_range;
 430
 431        for (i = 0; i < 2; i++) {
 432
 433                /* Set Fan pulse per revolution */
 434                err = i2c_smbus_write_byte_data(client,
 435                                MAX6639_REG_FAN_PPR(i),
 436                                data->ppr << 6);
 437                if (err)
 438                        goto exit;
 439
 440                /* Fans config PWM, RPM */
 441                err = i2c_smbus_write_byte_data(client,
 442                        MAX6639_REG_FAN_CONFIG1(i),
 443                        MAX6639_FAN_CONFIG1_PWM | rpm_range);
 444                if (err)
 445                        goto exit;
 446
 447                /* Fans PWM polarity high by default */
 448                if (max6639_info && max6639_info->pwm_polarity == 0)
 449                        err = i2c_smbus_write_byte_data(client,
 450                                MAX6639_REG_FAN_CONFIG2a(i), 0x00);
 451                else
 452                        err = i2c_smbus_write_byte_data(client,
 453                                MAX6639_REG_FAN_CONFIG2a(i), 0x02);
 454                if (err)
 455                        goto exit;
 456
 457                /*
 458                 * /THERM full speed enable,
 459                 * PWM frequency 25kHz, see also GCONFIG below
 460                 */
 461                err = i2c_smbus_write_byte_data(client,
 462                        MAX6639_REG_FAN_CONFIG3(i),
 463                        MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
 464                if (err)
 465                        goto exit;
 466
 467                /* Max. temp. 80C/90C/100C */
 468                data->temp_therm[i] = 80;
 469                data->temp_alert[i] = 90;
 470                data->temp_ot[i] = 100;
 471                err = i2c_smbus_write_byte_data(client,
 472                                MAX6639_REG_THERM_LIMIT(i),
 473                                data->temp_therm[i]);
 474                if (err)
 475                        goto exit;
 476                err = i2c_smbus_write_byte_data(client,
 477                                MAX6639_REG_ALERT_LIMIT(i),
 478                                data->temp_alert[i]);
 479                if (err)
 480                        goto exit;
 481                err = i2c_smbus_write_byte_data(client,
 482                                MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
 483                if (err)
 484                        goto exit;
 485
 486                /* PWM 120/120 (i.e. 100%) */
 487                data->pwm[i] = 120;
 488                err = i2c_smbus_write_byte_data(client,
 489                                MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
 490                if (err)
 491                        goto exit;
 492        }
 493        /* Start monitoring */
 494        err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
 495                MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
 496                MAX6639_GCONFIG_PWM_FREQ_HI);
 497exit:
 498        return err;
 499}
 500
 501/* Return 0 if detection is successful, -ENODEV otherwise */
 502static int max6639_detect(struct i2c_client *client,
 503                          struct i2c_board_info *info)
 504{
 505        struct i2c_adapter *adapter = client->adapter;
 506        int dev_id, manu_id;
 507
 508        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 509                return -ENODEV;
 510
 511        /* Actual detection via device and manufacturer ID */
 512        dev_id = i2c_smbus_read_byte_data(client, MAX6639_REG_DEVID);
 513        manu_id = i2c_smbus_read_byte_data(client, MAX6639_REG_MANUID);
 514        if (dev_id != 0x58 || manu_id != 0x4D)
 515                return -ENODEV;
 516
 517        strlcpy(info->type, "max6639", I2C_NAME_SIZE);
 518
 519        return 0;
 520}
 521
 522static void max6639_regulator_disable(void *data)
 523{
 524        regulator_disable(data);
 525}
 526
 527static int max6639_probe(struct i2c_client *client)
 528{
 529        struct device *dev = &client->dev;
 530        struct max6639_data *data;
 531        struct device *hwmon_dev;
 532        int err;
 533
 534        data = devm_kzalloc(dev, sizeof(struct max6639_data), GFP_KERNEL);
 535        if (!data)
 536                return -ENOMEM;
 537
 538        data->client = client;
 539
 540        data->reg = devm_regulator_get_optional(dev, "fan");
 541        if (IS_ERR(data->reg)) {
 542                if (PTR_ERR(data->reg) != -ENODEV)
 543                        return PTR_ERR(data->reg);
 544
 545                data->reg = NULL;
 546        } else {
 547                /* Spin up fans */
 548                err = regulator_enable(data->reg);
 549                if (err) {
 550                        dev_err(dev, "Failed to enable fan supply: %d\n", err);
 551                        return err;
 552                }
 553                err = devm_add_action_or_reset(dev, max6639_regulator_disable,
 554                                               data->reg);
 555                if (err) {
 556                        dev_err(dev, "Failed to register action: %d\n", err);
 557                        return err;
 558                }
 559        }
 560
 561        mutex_init(&data->update_lock);
 562
 563        /* Initialize the max6639 chip */
 564        err = max6639_init_client(client, data);
 565        if (err < 0)
 566                return err;
 567
 568        hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 569                                                           data,
 570                                                           max6639_groups);
 571        return PTR_ERR_OR_ZERO(hwmon_dev);
 572}
 573
 574#ifdef CONFIG_PM_SLEEP
 575static int max6639_suspend(struct device *dev)
 576{
 577        struct i2c_client *client = to_i2c_client(dev);
 578        struct max6639_data *data = dev_get_drvdata(dev);
 579        int ret = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
 580
 581        if (ret < 0)
 582                return ret;
 583
 584        if (data->reg)
 585                regulator_disable(data->reg);
 586
 587        return i2c_smbus_write_byte_data(client,
 588                        MAX6639_REG_GCONFIG, ret | MAX6639_GCONFIG_STANDBY);
 589}
 590
 591static int max6639_resume(struct device *dev)
 592{
 593        struct i2c_client *client = to_i2c_client(dev);
 594        struct max6639_data *data = dev_get_drvdata(dev);
 595        int ret;
 596
 597        if (data->reg) {
 598                ret = regulator_enable(data->reg);
 599                if (ret) {
 600                        dev_err(dev, "Failed to enable fan supply: %d\n", ret);
 601                        return ret;
 602                }
 603        }
 604
 605        ret = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
 606        if (ret < 0)
 607                return ret;
 608
 609        return i2c_smbus_write_byte_data(client,
 610                        MAX6639_REG_GCONFIG, ret & ~MAX6639_GCONFIG_STANDBY);
 611}
 612#endif /* CONFIG_PM_SLEEP */
 613
 614static const struct i2c_device_id max6639_id[] = {
 615        {"max6639", 0},
 616        { }
 617};
 618
 619MODULE_DEVICE_TABLE(i2c, max6639_id);
 620
 621static SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
 622
 623static struct i2c_driver max6639_driver = {
 624        .class = I2C_CLASS_HWMON,
 625        .driver = {
 626                   .name = "max6639",
 627                   .pm = &max6639_pm_ops,
 628                   },
 629        .probe_new = max6639_probe,
 630        .id_table = max6639_id,
 631        .detect = max6639_detect,
 632        .address_list = normal_i2c,
 633};
 634
 635module_i2c_driver(max6639_driver);
 636
 637MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
 638MODULE_DESCRIPTION("max6639 driver");
 639MODULE_LICENSE("GPL");
 640