linux/drivers/hwmon/max6639.c
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   1/*
   2 * max6639.c - Support for Maxim MAX6639
   3 *
   4 * 2-Channel Temperature Monitor with Dual PWM Fan-Speed Controller
   5 *
   6 * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
   7 *
   8 * based on the initial MAX6639 support from semptian.net
   9 * by He Changqing <hechangqing@semptian.com>
  10 *
  11 * This program is free software; you can redistribute it and/or modify
  12 * it under the terms of the GNU General Public License as published by
  13 * the Free Software Foundation; either version 2 of the License, or
  14 * (at your option) any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 * GNU General Public License for more details.
  20 *
  21 * You should have received a copy of the GNU General Public License
  22 * along with this program; if not, write to the Free Software
  23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24 */
  25
  26#include <linux/module.h>
  27#include <linux/init.h>
  28#include <linux/slab.h>
  29#include <linux/jiffies.h>
  30#include <linux/i2c.h>
  31#include <linux/hwmon.h>
  32#include <linux/hwmon-sysfs.h>
  33#include <linux/err.h>
  34#include <linux/mutex.h>
  35#include <linux/i2c/max6639.h>
  36
  37/* Addresses to scan */
  38static unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
  39
  40/* The MAX6639 registers, valid channel numbers: 0, 1 */
  41#define MAX6639_REG_TEMP(ch)                    (0x00 + (ch))
  42#define MAX6639_REG_STATUS                      0x02
  43#define MAX6639_REG_OUTPUT_MASK                 0x03
  44#define MAX6639_REG_GCONFIG                     0x04
  45#define MAX6639_REG_TEMP_EXT(ch)                (0x05 + (ch))
  46#define MAX6639_REG_ALERT_LIMIT(ch)             (0x08 + (ch))
  47#define MAX6639_REG_OT_LIMIT(ch)                (0x0A + (ch))
  48#define MAX6639_REG_THERM_LIMIT(ch)             (0x0C + (ch))
  49#define MAX6639_REG_FAN_CONFIG1(ch)             (0x10 + (ch) * 4)
  50#define MAX6639_REG_FAN_CONFIG2a(ch)            (0x11 + (ch) * 4)
  51#define MAX6639_REG_FAN_CONFIG2b(ch)            (0x12 + (ch) * 4)
  52#define MAX6639_REG_FAN_CONFIG3(ch)             (0x13 + (ch) * 4)
  53#define MAX6639_REG_FAN_CNT(ch)                 (0x20 + (ch))
  54#define MAX6639_REG_TARGET_CNT(ch)              (0x22 + (ch))
  55#define MAX6639_REG_FAN_PPR(ch)                 (0x24 + (ch))
  56#define MAX6639_REG_TARGTDUTY(ch)               (0x26 + (ch))
  57#define MAX6639_REG_FAN_START_TEMP(ch)          (0x28 + (ch))
  58#define MAX6639_REG_DEVID                       0x3D
  59#define MAX6639_REG_MANUID                      0x3E
  60#define MAX6639_REG_DEVREV                      0x3F
  61
  62/* Register bits */
  63#define MAX6639_GCONFIG_STANDBY                 0x80
  64#define MAX6639_GCONFIG_POR                     0x40
  65#define MAX6639_GCONFIG_DISABLE_TIMEOUT         0x20
  66#define MAX6639_GCONFIG_CH2_LOCAL               0x10
  67#define MAX6639_GCONFIG_PWM_FREQ_HI             0x08
  68
  69#define MAX6639_FAN_CONFIG1_PWM                 0x80
  70
  71#define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED    0x40
  72
  73static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
  74
  75#define FAN_FROM_REG(val, rpm_range)    ((val) == 0 || (val) == 255 ? \
  76                                0 : (rpm_ranges[rpm_range] * 30) / (val))
  77#define TEMP_LIMIT_TO_REG(val)  clamp_val((val) / 1000, 0, 255)
  78
  79/*
  80 * Client data (each client gets its own)
  81 */
  82struct max6639_data {
  83        struct device *hwmon_dev;
  84        struct mutex update_lock;
  85        char valid;             /* !=0 if following fields are valid */
  86        unsigned long last_updated;     /* In jiffies */
  87
  88        /* Register values sampled regularly */
  89        u16 temp[2];            /* Temperature, in 1/8 C, 0..255 C */
  90        bool temp_fault[2];     /* Detected temperature diode failure */
  91        u8 fan[2];              /* Register value: TACH count for fans >=30 */
  92        u8 status;              /* Detected channel alarms and fan failures */
  93
  94        /* Register values only written to */
  95        u8 pwm[2];              /* Register value: Duty cycle 0..120 */
  96        u8 temp_therm[2];       /* THERM Temperature, 0..255 C (->_max) */
  97        u8 temp_alert[2];       /* ALERT Temperature, 0..255 C (->_crit) */
  98        u8 temp_ot[2];          /* OT Temperature, 0..255 C (->_emergency) */
  99
 100        /* Register values initialized only once */
 101        u8 ppr;                 /* Pulses per rotation 0..3 for 1..4 ppr */
 102        u8 rpm_range;           /* Index in above rpm_ranges table */
 103};
 104
 105static struct max6639_data *max6639_update_device(struct device *dev)
 106{
 107        struct i2c_client *client = to_i2c_client(dev);
 108        struct max6639_data *data = i2c_get_clientdata(client);
 109        struct max6639_data *ret = data;
 110        int i;
 111        int status_reg;
 112
 113        mutex_lock(&data->update_lock);
 114
 115        if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
 116                int res;
 117
 118                dev_dbg(&client->dev, "Starting max6639 update\n");
 119
 120                status_reg = i2c_smbus_read_byte_data(client,
 121                                                      MAX6639_REG_STATUS);
 122                if (status_reg < 0) {
 123                        ret = ERR_PTR(status_reg);
 124                        goto abort;
 125                }
 126
 127                data->status = status_reg;
 128
 129                for (i = 0; i < 2; i++) {
 130                        res = i2c_smbus_read_byte_data(client,
 131                                        MAX6639_REG_FAN_CNT(i));
 132                        if (res < 0) {
 133                                ret = ERR_PTR(res);
 134                                goto abort;
 135                        }
 136                        data->fan[i] = res;
 137
 138                        res = i2c_smbus_read_byte_data(client,
 139                                        MAX6639_REG_TEMP_EXT(i));
 140                        if (res < 0) {
 141                                ret = ERR_PTR(res);
 142                                goto abort;
 143                        }
 144                        data->temp[i] = res >> 5;
 145                        data->temp_fault[i] = res & 0x01;
 146
 147                        res = i2c_smbus_read_byte_data(client,
 148                                        MAX6639_REG_TEMP(i));
 149                        if (res < 0) {
 150                                ret = ERR_PTR(res);
 151                                goto abort;
 152                        }
 153                        data->temp[i] |= res << 3;
 154                }
 155
 156                data->last_updated = jiffies;
 157                data->valid = 1;
 158        }
 159abort:
 160        mutex_unlock(&data->update_lock);
 161
 162        return ret;
 163}
 164
 165static ssize_t show_temp_input(struct device *dev,
 166                               struct device_attribute *dev_attr, char *buf)
 167{
 168        long temp;
 169        struct max6639_data *data = max6639_update_device(dev);
 170        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 171
 172        if (IS_ERR(data))
 173                return PTR_ERR(data);
 174
 175        temp = data->temp[attr->index] * 125;
 176        return sprintf(buf, "%ld\n", temp);
 177}
 178
 179static ssize_t show_temp_fault(struct device *dev,
 180                               struct device_attribute *dev_attr, char *buf)
 181{
 182        struct max6639_data *data = max6639_update_device(dev);
 183        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 184
 185        if (IS_ERR(data))
 186                return PTR_ERR(data);
 187
 188        return sprintf(buf, "%d\n", data->temp_fault[attr->index]);
 189}
 190
 191static ssize_t show_temp_max(struct device *dev,
 192                             struct device_attribute *dev_attr, char *buf)
 193{
 194        struct i2c_client *client = to_i2c_client(dev);
 195        struct max6639_data *data = i2c_get_clientdata(client);
 196        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 197
 198        return sprintf(buf, "%d\n", (data->temp_therm[attr->index] * 1000));
 199}
 200
 201static ssize_t set_temp_max(struct device *dev,
 202                            struct device_attribute *dev_attr,
 203                            const char *buf, size_t count)
 204{
 205        struct i2c_client *client = to_i2c_client(dev);
 206        struct max6639_data *data = i2c_get_clientdata(client);
 207        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 208        unsigned long val;
 209        int res;
 210
 211        res = kstrtoul(buf, 10, &val);
 212        if (res)
 213                return res;
 214
 215        mutex_lock(&data->update_lock);
 216        data->temp_therm[attr->index] = TEMP_LIMIT_TO_REG(val);
 217        i2c_smbus_write_byte_data(client,
 218                                  MAX6639_REG_THERM_LIMIT(attr->index),
 219                                  data->temp_therm[attr->index]);
 220        mutex_unlock(&data->update_lock);
 221        return count;
 222}
 223
 224static ssize_t show_temp_crit(struct device *dev,
 225                              struct device_attribute *dev_attr, char *buf)
 226{
 227        struct i2c_client *client = to_i2c_client(dev);
 228        struct max6639_data *data = i2c_get_clientdata(client);
 229        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 230
 231        return sprintf(buf, "%d\n", (data->temp_alert[attr->index] * 1000));
 232}
 233
 234static ssize_t set_temp_crit(struct device *dev,
 235                             struct device_attribute *dev_attr,
 236                             const char *buf, size_t count)
 237{
 238        struct i2c_client *client = to_i2c_client(dev);
 239        struct max6639_data *data = i2c_get_clientdata(client);
 240        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 241        unsigned long val;
 242        int res;
 243
 244        res = kstrtoul(buf, 10, &val);
 245        if (res)
 246                return res;
 247
 248        mutex_lock(&data->update_lock);
 249        data->temp_alert[attr->index] = TEMP_LIMIT_TO_REG(val);
 250        i2c_smbus_write_byte_data(client,
 251                                  MAX6639_REG_ALERT_LIMIT(attr->index),
 252                                  data->temp_alert[attr->index]);
 253        mutex_unlock(&data->update_lock);
 254        return count;
 255}
 256
 257static ssize_t show_temp_emergency(struct device *dev,
 258                                   struct device_attribute *dev_attr,
 259                                   char *buf)
 260{
 261        struct i2c_client *client = to_i2c_client(dev);
 262        struct max6639_data *data = i2c_get_clientdata(client);
 263        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 264
 265        return sprintf(buf, "%d\n", (data->temp_ot[attr->index] * 1000));
 266}
 267
 268static ssize_t set_temp_emergency(struct device *dev,
 269                                  struct device_attribute *dev_attr,
 270                                  const char *buf, size_t count)
 271{
 272        struct i2c_client *client = to_i2c_client(dev);
 273        struct max6639_data *data = i2c_get_clientdata(client);
 274        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 275        unsigned long val;
 276        int res;
 277
 278        res = kstrtoul(buf, 10, &val);
 279        if (res)
 280                return res;
 281
 282        mutex_lock(&data->update_lock);
 283        data->temp_ot[attr->index] = TEMP_LIMIT_TO_REG(val);
 284        i2c_smbus_write_byte_data(client,
 285                                  MAX6639_REG_OT_LIMIT(attr->index),
 286                                  data->temp_ot[attr->index]);
 287        mutex_unlock(&data->update_lock);
 288        return count;
 289}
 290
 291static ssize_t show_pwm(struct device *dev,
 292                        struct device_attribute *dev_attr, char *buf)
 293{
 294        struct i2c_client *client = to_i2c_client(dev);
 295        struct max6639_data *data = i2c_get_clientdata(client);
 296        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 297
 298        return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
 299}
 300
 301static ssize_t set_pwm(struct device *dev,
 302                       struct device_attribute *dev_attr,
 303                       const char *buf, size_t count)
 304{
 305        struct i2c_client *client = to_i2c_client(dev);
 306        struct max6639_data *data = i2c_get_clientdata(client);
 307        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 308        unsigned long val;
 309        int res;
 310
 311        res = kstrtoul(buf, 10, &val);
 312        if (res)
 313                return res;
 314
 315        val = clamp_val(val, 0, 255);
 316
 317        mutex_lock(&data->update_lock);
 318        data->pwm[attr->index] = (u8)(val * 120 / 255);
 319        i2c_smbus_write_byte_data(client,
 320                                  MAX6639_REG_TARGTDUTY(attr->index),
 321                                  data->pwm[attr->index]);
 322        mutex_unlock(&data->update_lock);
 323        return count;
 324}
 325
 326static ssize_t show_fan_input(struct device *dev,
 327                              struct device_attribute *dev_attr, char *buf)
 328{
 329        struct max6639_data *data = max6639_update_device(dev);
 330        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 331
 332        if (IS_ERR(data))
 333                return PTR_ERR(data);
 334
 335        return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
 336                       data->rpm_range));
 337}
 338
 339static ssize_t show_alarm(struct device *dev,
 340                          struct device_attribute *dev_attr, char *buf)
 341{
 342        struct max6639_data *data = max6639_update_device(dev);
 343        struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 344
 345        if (IS_ERR(data))
 346                return PTR_ERR(data);
 347
 348        return sprintf(buf, "%d\n", !!(data->status & (1 << attr->index)));
 349}
 350
 351static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);
 352static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input, NULL, 1);
 353static SENSOR_DEVICE_ATTR(temp1_fault, S_IRUGO, show_temp_fault, NULL, 0);
 354static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_temp_fault, NULL, 1);
 355static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
 356                set_temp_max, 0);
 357static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_max,
 358                set_temp_max, 1);
 359static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp_crit,
 360                set_temp_crit, 0);
 361static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit,
 362                set_temp_crit, 1);
 363static SENSOR_DEVICE_ATTR(temp1_emergency, S_IWUSR | S_IRUGO,
 364                show_temp_emergency, set_temp_emergency, 0);
 365static SENSOR_DEVICE_ATTR(temp2_emergency, S_IWUSR | S_IRUGO,
 366                show_temp_emergency, set_temp_emergency, 1);
 367static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 0);
 368static SENSOR_DEVICE_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 1);
 369static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan_input, NULL, 0);
 370static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan_input, NULL, 1);
 371static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, show_alarm, NULL, 1);
 372static SENSOR_DEVICE_ATTR(fan2_fault, S_IRUGO, show_alarm, NULL, 0);
 373static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 3);
 374static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 2);
 375static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 7);
 376static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 6);
 377static SENSOR_DEVICE_ATTR(temp1_emergency_alarm, S_IRUGO, show_alarm, NULL, 5);
 378static SENSOR_DEVICE_ATTR(temp2_emergency_alarm, S_IRUGO, show_alarm, NULL, 4);
 379
 380
 381static struct attribute *max6639_attributes[] = {
 382        &sensor_dev_attr_temp1_input.dev_attr.attr,
 383        &sensor_dev_attr_temp2_input.dev_attr.attr,
 384        &sensor_dev_attr_temp1_fault.dev_attr.attr,
 385        &sensor_dev_attr_temp2_fault.dev_attr.attr,
 386        &sensor_dev_attr_temp1_max.dev_attr.attr,
 387        &sensor_dev_attr_temp2_max.dev_attr.attr,
 388        &sensor_dev_attr_temp1_crit.dev_attr.attr,
 389        &sensor_dev_attr_temp2_crit.dev_attr.attr,
 390        &sensor_dev_attr_temp1_emergency.dev_attr.attr,
 391        &sensor_dev_attr_temp2_emergency.dev_attr.attr,
 392        &sensor_dev_attr_pwm1.dev_attr.attr,
 393        &sensor_dev_attr_pwm2.dev_attr.attr,
 394        &sensor_dev_attr_fan1_input.dev_attr.attr,
 395        &sensor_dev_attr_fan2_input.dev_attr.attr,
 396        &sensor_dev_attr_fan1_fault.dev_attr.attr,
 397        &sensor_dev_attr_fan2_fault.dev_attr.attr,
 398        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 399        &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 400        &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 401        &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 402        &sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
 403        &sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
 404        NULL
 405};
 406
 407static const struct attribute_group max6639_group = {
 408        .attrs = max6639_attributes,
 409};
 410
 411/*
 412 *  returns respective index in rpm_ranges table
 413 *  1 by default on invalid range
 414 */
 415static int rpm_range_to_reg(int range)
 416{
 417        int i;
 418
 419        for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
 420                if (rpm_ranges[i] == range)
 421                        return i;
 422        }
 423
 424        return 1; /* default: 4000 RPM */
 425}
 426
 427static int max6639_init_client(struct i2c_client *client)
 428{
 429        struct max6639_data *data = i2c_get_clientdata(client);
 430        struct max6639_platform_data *max6639_info =
 431                client->dev.platform_data;
 432        int i;
 433        int rpm_range = 1; /* default: 4000 RPM */
 434        int err;
 435
 436        /* Reset chip to default values, see below for GCONFIG setup */
 437        err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
 438                                  MAX6639_GCONFIG_POR);
 439        if (err)
 440                goto exit;
 441
 442        /* Fans pulse per revolution is 2 by default */
 443        if (max6639_info && max6639_info->ppr > 0 &&
 444                        max6639_info->ppr < 5)
 445                data->ppr = max6639_info->ppr;
 446        else
 447                data->ppr = 2;
 448        data->ppr -= 1;
 449
 450        if (max6639_info)
 451                rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
 452        data->rpm_range = rpm_range;
 453
 454        for (i = 0; i < 2; i++) {
 455
 456                /* Set Fan pulse per revolution */
 457                err = i2c_smbus_write_byte_data(client,
 458                                MAX6639_REG_FAN_PPR(i),
 459                                data->ppr << 6);
 460                if (err)
 461                        goto exit;
 462
 463                /* Fans config PWM, RPM */
 464                err = i2c_smbus_write_byte_data(client,
 465                        MAX6639_REG_FAN_CONFIG1(i),
 466                        MAX6639_FAN_CONFIG1_PWM | rpm_range);
 467                if (err)
 468                        goto exit;
 469
 470                /* Fans PWM polarity high by default */
 471                if (max6639_info && max6639_info->pwm_polarity == 0)
 472                        err = i2c_smbus_write_byte_data(client,
 473                                MAX6639_REG_FAN_CONFIG2a(i), 0x00);
 474                else
 475                        err = i2c_smbus_write_byte_data(client,
 476                                MAX6639_REG_FAN_CONFIG2a(i), 0x02);
 477                if (err)
 478                        goto exit;
 479
 480                /*
 481                 * /THERM full speed enable,
 482                 * PWM frequency 25kHz, see also GCONFIG below
 483                 */
 484                err = i2c_smbus_write_byte_data(client,
 485                        MAX6639_REG_FAN_CONFIG3(i),
 486                        MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
 487                if (err)
 488                        goto exit;
 489
 490                /* Max. temp. 80C/90C/100C */
 491                data->temp_therm[i] = 80;
 492                data->temp_alert[i] = 90;
 493                data->temp_ot[i] = 100;
 494                err = i2c_smbus_write_byte_data(client,
 495                                MAX6639_REG_THERM_LIMIT(i),
 496                                data->temp_therm[i]);
 497                if (err)
 498                        goto exit;
 499                err = i2c_smbus_write_byte_data(client,
 500                                MAX6639_REG_ALERT_LIMIT(i),
 501                                data->temp_alert[i]);
 502                if (err)
 503                        goto exit;
 504                err = i2c_smbus_write_byte_data(client,
 505                                MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
 506                if (err)
 507                        goto exit;
 508
 509                /* PWM 120/120 (i.e. 100%) */
 510                data->pwm[i] = 120;
 511                err = i2c_smbus_write_byte_data(client,
 512                                MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
 513                if (err)
 514                        goto exit;
 515        }
 516        /* Start monitoring */
 517        err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
 518                MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
 519                MAX6639_GCONFIG_PWM_FREQ_HI);
 520exit:
 521        return err;
 522}
 523
 524/* Return 0 if detection is successful, -ENODEV otherwise */
 525static int max6639_detect(struct i2c_client *client,
 526                          struct i2c_board_info *info)
 527{
 528        struct i2c_adapter *adapter = client->adapter;
 529        int dev_id, manu_id;
 530
 531        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 532                return -ENODEV;
 533
 534        /* Actual detection via device and manufacturer ID */
 535        dev_id = i2c_smbus_read_byte_data(client, MAX6639_REG_DEVID);
 536        manu_id = i2c_smbus_read_byte_data(client, MAX6639_REG_MANUID);
 537        if (dev_id != 0x58 || manu_id != 0x4D)
 538                return -ENODEV;
 539
 540        strlcpy(info->type, "max6639", I2C_NAME_SIZE);
 541
 542        return 0;
 543}
 544
 545static int max6639_probe(struct i2c_client *client,
 546                         const struct i2c_device_id *id)
 547{
 548        struct max6639_data *data;
 549        int err;
 550
 551        data = devm_kzalloc(&client->dev, sizeof(struct max6639_data),
 552                            GFP_KERNEL);
 553        if (!data)
 554                return -ENOMEM;
 555
 556        i2c_set_clientdata(client, data);
 557        mutex_init(&data->update_lock);
 558
 559        /* Initialize the max6639 chip */
 560        err = max6639_init_client(client);
 561        if (err < 0)
 562                return err;
 563
 564        /* Register sysfs hooks */
 565        err = sysfs_create_group(&client->dev.kobj, &max6639_group);
 566        if (err)
 567                return err;
 568
 569        data->hwmon_dev = hwmon_device_register(&client->dev);
 570        if (IS_ERR(data->hwmon_dev)) {
 571                err = PTR_ERR(data->hwmon_dev);
 572                goto error_remove;
 573        }
 574
 575        dev_info(&client->dev, "temperature sensor and fan control found\n");
 576
 577        return 0;
 578
 579error_remove:
 580        sysfs_remove_group(&client->dev.kobj, &max6639_group);
 581        return err;
 582}
 583
 584static int max6639_remove(struct i2c_client *client)
 585{
 586        struct max6639_data *data = i2c_get_clientdata(client);
 587
 588        hwmon_device_unregister(data->hwmon_dev);
 589        sysfs_remove_group(&client->dev.kobj, &max6639_group);
 590
 591        return 0;
 592}
 593
 594#ifdef CONFIG_PM_SLEEP
 595static int max6639_suspend(struct device *dev)
 596{
 597        struct i2c_client *client = to_i2c_client(dev);
 598        int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
 599        if (data < 0)
 600                return data;
 601
 602        return i2c_smbus_write_byte_data(client,
 603                        MAX6639_REG_GCONFIG, data | MAX6639_GCONFIG_STANDBY);
 604}
 605
 606static int max6639_resume(struct device *dev)
 607{
 608        struct i2c_client *client = to_i2c_client(dev);
 609        int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
 610        if (data < 0)
 611                return data;
 612
 613        return i2c_smbus_write_byte_data(client,
 614                        MAX6639_REG_GCONFIG, data & ~MAX6639_GCONFIG_STANDBY);
 615}
 616#endif /* CONFIG_PM_SLEEP */
 617
 618static const struct i2c_device_id max6639_id[] = {
 619        {"max6639", 0},
 620        { }
 621};
 622
 623MODULE_DEVICE_TABLE(i2c, max6639_id);
 624
 625static const struct dev_pm_ops max6639_pm_ops = {
 626        SET_SYSTEM_SLEEP_PM_OPS(max6639_suspend, max6639_resume)
 627};
 628
 629static struct i2c_driver max6639_driver = {
 630        .class = I2C_CLASS_HWMON,
 631        .driver = {
 632                   .name = "max6639",
 633                   .pm = &max6639_pm_ops,
 634                   },
 635        .probe = max6639_probe,
 636        .remove = max6639_remove,
 637        .id_table = max6639_id,
 638        .detect = max6639_detect,
 639        .address_list = normal_i2c,
 640};
 641
 642module_i2c_driver(max6639_driver);
 643
 644MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
 645MODULE_DESCRIPTION("max6639 driver");
 646MODULE_LICENSE("GPL");
 647