drivers/hwmon/jc42.c

   1 /*
   2  * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
   3  *
   4  * Copyright (c) 2010  Ericsson AB.
   5  *
   6  * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
   7  *
   8  * JC42.4 compliant temperature sensors are typically used on memory modules.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/slab.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/i2c.h>
  30 #include <linux/hwmon.h>
  31 #include <linux/hwmon-sysfs.h>
  32 #include <linux/err.h>
  33 #include <linux/mutex.h>
  34
  35 /* Addresses to scan */
  36 static const unsigned short normal_i2c[] = {
  37         0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
  38
  39 /* JC42 registers. All registers are 16 bit. */
  40 #define JC42_REG_CAP            0x00
  41 #define JC42_REG_CONFIG         0x01
  42 #define JC42_REG_TEMP_UPPER     0x02
  43 #define JC42_REG_TEMP_LOWER     0x03
  44 #define JC42_REG_TEMP_CRITICAL  0x04
  45 #define JC42_REG_TEMP           0x05
  46 #define JC42_REG_MANID          0x06
  47 #define JC42_REG_DEVICEID       0x07
  48
  49 /* Status bits in temperature register */
  50 #define JC42_ALARM_CRIT_BIT     15
  51 #define JC42_ALARM_MAX_BIT      14
  52 #define JC42_ALARM_MIN_BIT      13
  53
  54 /* Configuration register defines */
  55 #define JC42_CFG_CRIT_ONLY      (1 << 2)
  56 #define JC42_CFG_TCRIT_LOCK     (1 << 6)
  57 #define JC42_CFG_EVENT_LOCK     (1 << 7)
  58 #define JC42_CFG_SHUTDOWN       (1 << 8)
  59 #define JC42_CFG_HYST_SHIFT     9
  60 #define JC42_CFG_HYST_MASK      0x03
  61
  62 /* Capabilities */
  63 #define JC42_CAP_RANGE          (1 << 2)
  64
  65 /* Manufacturer IDs */
  66 #define ADT_MANID               0x11d4  /* Analog Devices */
  67 #define MAX_MANID               0x004d  /* Maxim */
  68 #define IDT_MANID               0x00b3  /* IDT */
  69 #define MCP_MANID               0x0054  /* Microchip */
  70 #define NXP_MANID               0x1131  /* NXP Semiconductors */
  71 #define ONS_MANID               0x1b09  /* ON Semiconductor */
  72 #define STM_MANID               0x104a  /* ST Microelectronics */
  73
  74 /* Supported chips */
  75
  76 /* Analog Devices */
  77 #define ADT7408_DEVID           0x0801
  78 #define ADT7408_DEVID_MASK      0xffff
  79
  80 /* IDT */
  81 #define TS3000B3_DEVID          0x2903  /* Also matches TSE2002B3 */
  82 #define TS3000B3_DEVID_MASK     0xffff
  83
  84 /* Maxim */
  85 #define MAX6604_DEVID           0x3e00
  86 #define MAX6604_DEVID_MASK      0xffff
  87
  88 /* Microchip */
  89 #define MCP98242_DEVID          0x2000
  90 #define MCP98242_DEVID_MASK     0xfffc
  91
  92 #define MCP98243_DEVID          0x2100
  93 #define MCP98243_DEVID_MASK     0xfffc
  94
  95 #define MCP9843_DEVID           0x0000  /* Also matches mcp9805 */
  96 #define MCP9843_DEVID_MASK      0xfffe
  97
  98 /* NXP */
  99 #define SE97_DEVID              0xa200
 100 #define SE97_DEVID_MASK         0xfffc
 101
 102 #define SE98_DEVID              0xa100
 103 #define SE98_DEVID_MASK         0xfffc
 104
 105 /* ON Semiconductor */
 106 #define CAT6095_DEVID           0x0800  /* Also matches CAT34TS02 */
 107 #define CAT6095_DEVID_MASK      0xffe0
 108
 109 /* ST Microelectronics */
 110 #define STTS424_DEVID           0x0101
 111 #define STTS424_DEVID_MASK      0xffff
 112
 113 #define STTS424E_DEVID          0x0000
 114 #define STTS424E_DEVID_MASK     0xfffe
 115
 116 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
 117
 118 struct jc42_chips {
 119         u16 manid;
 120         u16 devid;
 121         u16 devid_mask;
 122 };
 123
 124 static struct jc42_chips jc42_chips[] = {
 125         { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
 126         { IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
 127         { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
 128         { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
 129         { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
 130         { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
 131         { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
 132         { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
 133         { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
 134         { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
 135         { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
 136 };
 137
 138 /* Each client has this additional data */
 139 struct jc42_data {
 140         struct device   *hwmon_dev;
 141         struct mutex    update_lock;    /* protect register access */
 142         bool            extended;       /* true if extended range supported */
 143         bool            valid;
 144         unsigned long   last_updated;   /* In jiffies */
 145         u16             orig_config;    /* original configuration */
 146         u16             config;         /* current configuration */
 147         u16             temp_input;     /* Temperatures */
 148         u16             temp_crit;
 149         u16             temp_min;
 150         u16             temp_max;
 151 };
 152
 153 static int jc42_probe(struct i2c_client *client,
 154                       const struct i2c_device_id *id);
 155 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info);
 156 static int jc42_remove(struct i2c_client *client);
 157 static int jc42_read_value(struct i2c_client *client, u8 reg);
 158 static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value);
 159
 160 static struct jc42_data *jc42_update_device(struct device *dev);
 161
 162 static const struct i2c_device_id jc42_id[] = {
 163         { "adt7408", 0 },
 164         { "cat94ts02", 0 },
 165         { "cat6095", 0 },
 166         { "jc42", 0 },
 167         { "max6604", 0 },
 168         { "mcp9805", 0 },
 169         { "mcp98242", 0 },
 170         { "mcp98243", 0 },
 171         { "mcp9843", 0 },
 172         { "se97", 0 },
 173         { "se97b", 0 },
 174         { "se98", 0 },
 175         { "stts424", 0 },
 176         { "tse2002b3", 0 },
 177         { "ts3000b3", 0 },
 178         { }
 179 };
 180 MODULE_DEVICE_TABLE(i2c, jc42_id);
 181
 182 #ifdef CONFIG_PM
 183
 184 static int jc42_suspend(struct device *dev)
 185 {
 186         struct i2c_client *client = to_i2c_client(dev);
 187         struct jc42_data *data = i2c_get_clientdata(client);
 188
 189         data->config |= JC42_CFG_SHUTDOWN;
 190         jc42_write_value(client, JC42_REG_CONFIG, data->config);
 191         return 0;
 192 }
 193
 194 static int jc42_resume(struct device *dev)
 195 {
 196         struct i2c_client *client = to_i2c_client(dev);
 197         struct jc42_data *data = i2c_get_clientdata(client);
 198
 199         data->config &= ~JC42_CFG_SHUTDOWN;
 200         jc42_write_value(client, JC42_REG_CONFIG, data->config);
 201         return 0;
 202 }
 203
 204 static const struct dev_pm_ops jc42_dev_pm_ops = {
 205         .suspend = jc42_suspend,
 206         .resume = jc42_resume,
 207 };
 208
 209 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
 210 #else
 211 #define JC42_DEV_PM_OPS NULL
 212 #endif /* CONFIG_PM */
 213
 214 /* This is the driver that will be inserted */
 215 static struct i2c_driver jc42_driver = {
 216         .class          = I2C_CLASS_HWMON,
 217         .driver = {
 218                 .name   = "jc42",
 219                 .pm = JC42_DEV_PM_OPS,
 220         },
 221         .probe          = jc42_probe,
 222         .remove         = jc42_remove,
 223         .id_table       = jc42_id,
 224         .detect         = jc42_detect,
 225         .address_list   = normal_i2c,
 226 };
 227
 228 #define JC42_TEMP_MIN_EXTENDED  (-40000)
 229 #define JC42_TEMP_MIN           0
 230 #define JC42_TEMP_MAX           125000
 231
 232 static u16 jc42_temp_to_reg(int temp, bool extended)
 233 {
 234         int ntemp = SENSORS_LIMIT(temp,
 235                                   extended ? JC42_TEMP_MIN_EXTENDED :
 236                                   JC42_TEMP_MIN, JC42_TEMP_MAX);
 237
 238         /* convert from 0.001 to 0.0625 resolution */
 239         return (ntemp * 2 / 125) & 0x1fff;
 240 }
 241
 242 static int jc42_temp_from_reg(s16 reg)
 243 {
 244         reg &= 0x1fff;
 245
 246         /* sign extend register */
 247         if (reg & 0x1000)
 248                 reg |= 0xf000;
 249
 250         /* convert from 0.0625 to 0.001 resolution */
 251         return reg * 125 / 2;
 252 }
 253
 254 /* sysfs stuff */
 255
 256 /* read routines for temperature limits */
 257 #define show(value)     \
 258 static ssize_t show_##value(struct device *dev,                         \
 259                             struct device_attribute *attr,              \
 260                             char *buf)                                  \
 261 {                                                                       \
 262         struct jc42_data *data = jc42_update_device(dev);               \
 263         if (IS_ERR(data))                                               \
 264                 return PTR_ERR(data);                                   \
 265         return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value));   \
 266 }
 267
 268 show(temp_input);
 269 show(temp_crit);
 270 show(temp_min);
 271 show(temp_max);
 272
 273 /* read routines for hysteresis values */
 274 static ssize_t show_temp_crit_hyst(struct device *dev,
 275                                    struct device_attribute *attr, char *buf)
 276 {
 277         struct jc42_data *data = jc42_update_device(dev);
 278         int temp, hyst;
 279
 280         if (IS_ERR(data))
 281                 return PTR_ERR(data);
 282
 283         temp = jc42_temp_from_reg(data->temp_crit);
 284         hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
 285                                & JC42_CFG_HYST_MASK];
 286         return sprintf(buf, "%d\n", temp - hyst);
 287 }
 288
 289 static ssize_t show_temp_max_hyst(struct device *dev,
 290                                   struct device_attribute *attr, char *buf)
 291 {
 292         struct jc42_data *data = jc42_update_device(dev);
 293         int temp, hyst;
 294
 295         if (IS_ERR(data))
 296                 return PTR_ERR(data);
 297
 298         temp = jc42_temp_from_reg(data->temp_max);
 299         hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
 300                                & JC42_CFG_HYST_MASK];
 301         return sprintf(buf, "%d\n", temp - hyst);
 302 }
 303
 304 /* write routines */
 305 #define set(value, reg) \
 306 static ssize_t set_##value(struct device *dev,                          \
 307                            struct device_attribute *attr,               \
 308                            const char *buf, size_t count)               \
 309 {                                                                       \
 310         struct i2c_client *client = to_i2c_client(dev);                 \
 311         struct jc42_data *data = i2c_get_clientdata(client);            \
 312         int err, ret = count;                                           \
 313         long val;                                                       \
 314         if (strict_strtol(buf, 10, &val) < 0)                           \
 315                 return -EINVAL;                                         \
 316         mutex_lock(&data->update_lock);                                 \
 317         data->value = jc42_temp_to_reg(val, data->extended);            \
 318         err = jc42_write_value(client, reg, data->value);               \
 319         if (err < 0)                                                    \
 320                 ret = err;                                              \
 321         mutex_unlock(&data->update_lock);                               \
 322         return ret;                                                     \
 323 }
 324
 325 set(temp_min, JC42_REG_TEMP_LOWER);
 326 set(temp_max, JC42_REG_TEMP_UPPER);
 327 set(temp_crit, JC42_REG_TEMP_CRITICAL);
 328
 329 /* JC42.4 compliant chips only support four hysteresis values.
 330  * Pick best choice and go from there. */
 331 static ssize_t set_temp_crit_hyst(struct device *dev,
 332                                   struct device_attribute *attr,
 333                                   const char *buf, size_t count)
 334 {
 335         struct i2c_client *client = to_i2c_client(dev);
 336         struct jc42_data *data = i2c_get_clientdata(client);
 337         unsigned long val;
 338         int diff, hyst;
 339         int err;
 340         int ret = count;
 341
 342         if (strict_strtoul(buf, 10, &val) < 0)
 343                 return -EINVAL;
 344
 345         diff = jc42_temp_from_reg(data->temp_crit) - val;
 346         hyst = 0;
 347         if (diff > 0) {
 348                 if (diff < 2250)
 349                         hyst = 1;       /* 1.5 degrees C */
 350                 else if (diff < 4500)
 351                         hyst = 2;       /* 3.0 degrees C */
 352                 else
 353                         hyst = 3;       /* 6.0 degrees C */
 354         }
 355
 356         mutex_lock(&data->update_lock);
 357         data->config = (data->config
 358                         & ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT))
 359           | (hyst << JC42_CFG_HYST_SHIFT);
 360         err = jc42_write_value(client, JC42_REG_CONFIG, data->config);
 361         if (err < 0)
 362                 ret = err;
 363         mutex_unlock(&data->update_lock);
 364         return ret;
 365 }
 366
 367 static ssize_t show_alarm(struct device *dev,
 368                           struct device_attribute *attr, char *buf)
 369 {
 370         u16 bit = to_sensor_dev_attr(attr)->index;
 371         struct jc42_data *data = jc42_update_device(dev);
 372         u16 val;
 373
 374         if (IS_ERR(data))
 375                 return PTR_ERR(data);
 376
 377         val = data->temp_input;
 378         if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
 379                 val = 0;
 380         return sprintf(buf, "%u\n", (val >> bit) & 1);
 381 }
 382
 383 static DEVICE_ATTR(temp1_input, S_IRUGO,
 384                    show_temp_input, NULL);
 385 static DEVICE_ATTR(temp1_crit, S_IRUGO,
 386                    show_temp_crit, set_temp_crit);
 387 static DEVICE_ATTR(temp1_min, S_IRUGO,
 388                    show_temp_min, set_temp_min);
 389 static DEVICE_ATTR(temp1_max, S_IRUGO,
 390                    show_temp_max, set_temp_max);
 391
 392 static DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
 393                    show_temp_crit_hyst, set_temp_crit_hyst);
 394 static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
 395                    show_temp_max_hyst, NULL);
 396
 397 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
 398                           JC42_ALARM_CRIT_BIT);
 399 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
 400                           JC42_ALARM_MIN_BIT);
 401 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
 402                           JC42_ALARM_MAX_BIT);
 403
 404 static struct attribute *jc42_attributes[] = {
 405         &dev_attr_temp1_input.attr,
 406         &dev_attr_temp1_crit.attr,
 407         &dev_attr_temp1_min.attr,
 408         &dev_attr_temp1_max.attr,
 409         &dev_attr_temp1_crit_hyst.attr,
 410         &dev_attr_temp1_max_hyst.attr,
 411         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 412         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 413         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 414         NULL
 415 };
 416
 417 static mode_t jc42_attribute_mode(struct kobject *kobj,
 418                                   struct attribute *attr, int index)
 419 {
 420         struct device *dev = container_of(kobj, struct device, kobj);
 421         struct i2c_client *client = to_i2c_client(dev);
 422         struct jc42_data *data = i2c_get_clientdata(client);
 423         unsigned int config = data->config;
 424         bool readonly;
 425
 426         if (attr == &dev_attr_temp1_crit.attr)
 427                 readonly = config & JC42_CFG_TCRIT_LOCK;
 428         else if (attr == &dev_attr_temp1_min.attr ||
 429                  attr == &dev_attr_temp1_max.attr)
 430                 readonly = config & JC42_CFG_EVENT_LOCK;
 431         else if (attr == &dev_attr_temp1_crit_hyst.attr)
 432                 readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
 433         else
 434                 readonly = true;
 435
 436         return S_IRUGO | (readonly ? 0 : S_IWUSR);
 437 }
 438
 439 static const struct attribute_group jc42_group = {
 440         .attrs = jc42_attributes,
 441         .is_visible = jc42_attribute_mode,
 442 };
 443
 444 /* Return 0 if detection is successful, -ENODEV otherwise */
 445 static int jc42_detect(struct i2c_client *new_client,
 446                        struct i2c_board_info *info)
 447 {
 448         struct i2c_adapter *adapter = new_client->adapter;
 449         int i, config, cap, manid, devid;
 450
 451         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 452                                      I2C_FUNC_SMBUS_WORD_DATA))
 453                 return -ENODEV;
 454
 455         cap = jc42_read_value(new_client, JC42_REG_CAP);
 456         config = jc42_read_value(new_client, JC42_REG_CONFIG);
 457         manid = jc42_read_value(new_client, JC42_REG_MANID);
 458         devid = jc42_read_value(new_client, JC42_REG_DEVICEID);
 459
 460         if (cap < 0 || config < 0 || manid < 0 || devid < 0)
 461                 return -ENODEV;
 462
 463         if ((cap & 0xff00) || (config & 0xf800))
 464                 return -ENODEV;
 465
 466         for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
 467                 struct jc42_chips *chip = &jc42_chips[i];
 468                 if (manid == chip->manid &&
 469                     (devid & chip->devid_mask) == chip->devid) {
 470                         strlcpy(info->type, "jc42", I2C_NAME_SIZE);
 471                         return 0;
 472                 }
 473         }
 474         return -ENODEV;
 475 }
 476
 477 static int jc42_probe(struct i2c_client *new_client,
 478                       const struct i2c_device_id *id)
 479 {
 480         struct jc42_data *data;
 481         int config, cap, err;
 482
 483         data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL);
 484         if (!data) {
 485                 err = -ENOMEM;
 486                 goto exit;
 487         }
 488
 489         i2c_set_clientdata(new_client, data);
 490         mutex_init(&data->update_lock);
 491
 492         cap = jc42_read_value(new_client, JC42_REG_CAP);
 493         if (cap < 0) {
 494                 err = -EINVAL;
 495                 goto exit_free;
 496         }
 497         data->extended = !!(cap & JC42_CAP_RANGE);
 498
 499         config = jc42_read_value(new_client, JC42_REG_CONFIG);
 500         if (config < 0) {
 501                 err = -EINVAL;
 502                 goto exit_free;
 503         }
 504         data->orig_config = config;
 505         if (config & JC42_CFG_SHUTDOWN) {
 506                 config &= ~JC42_CFG_SHUTDOWN;
 507                 jc42_write_value(new_client, JC42_REG_CONFIG, config);
 508         }
 509         data->config = config;
 510
 511         /* Register sysfs hooks */
 512         err = sysfs_create_group(&new_client->dev.kobj, &jc42_group);
 513         if (err)
 514                 goto exit_free;
 515
 516         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 517         if (IS_ERR(data->hwmon_dev)) {
 518                 err = PTR_ERR(data->hwmon_dev);
 519                 goto exit_remove;
 520         }
 521
 522         return 0;
 523
 524 exit_remove:
 525         sysfs_remove_group(&new_client->dev.kobj, &jc42_group);
 526 exit_free:
 527         kfree(data);
 528 exit:
 529         return err;
 530 }
 531
 532 static int jc42_remove(struct i2c_client *client)
 533 {
 534         struct jc42_data *data = i2c_get_clientdata(client);
 535         hwmon_device_unregister(data->hwmon_dev);
 536         sysfs_remove_group(&client->dev.kobj, &jc42_group);
 537         if (data->config != data->orig_config)
 538                 jc42_write_value(client, JC42_REG_CONFIG, data->orig_config);
 539         kfree(data);
 540         return 0;
 541 }
 542
 543 /* All registers are word-sized. */
 544 static int jc42_read_value(struct i2c_client *client, u8 reg)
 545 {
 546         int ret = i2c_smbus_read_word_data(client, reg);
 547         if (ret < 0)
 548                 return ret;
 549         return swab16(ret);
 550 }
 551
 552 static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value)
 553 {
 554         return i2c_smbus_write_word_data(client, reg, swab16(value));
 555 }
 556
 557 static struct jc42_data *jc42_update_device(struct device *dev)
 558 {
 559         struct i2c_client *client = to_i2c_client(dev);
 560         struct jc42_data *data = i2c_get_clientdata(client);
 561         struct jc42_data *ret = data;
 562         int val;
 563
 564         mutex_lock(&data->update_lock);
 565
 566         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
 567                 val = jc42_read_value(client, JC42_REG_TEMP);
 568                 if (val < 0) {
 569                         ret = ERR_PTR(val);
 570                         goto abort;
 571                 }
 572                 data->temp_input = val;
 573
 574                 val = jc42_read_value(client, JC42_REG_TEMP_CRITICAL);
 575                 if (val < 0) {
 576                         ret = ERR_PTR(val);
 577                         goto abort;
 578                 }
 579                 data->temp_crit = val;
 580
 581                 val = jc42_read_value(client, JC42_REG_TEMP_LOWER);
 582                 if (val < 0) {
 583                         ret = ERR_PTR(val);
 584                         goto abort;
 585                 }
 586                 data->temp_min = val;
 587
 588                 val = jc42_read_value(client, JC42_REG_TEMP_UPPER);
 589                 if (val < 0) {
 590                         ret = ERR_PTR(val);
 591                         goto abort;
 592                 }
 593                 data->temp_max = val;
 594
 595                 data->last_updated = jiffies;
 596                 data->valid = true;
 597         }
 598 abort:
 599         mutex_unlock(&data->update_lock);
 600         return ret;
 601 }
 602
 603 static int __init sensors_jc42_init(void)
 604 {
 605         return i2c_add_driver(&jc42_driver);
 606 }
 607
 608 static void __exit sensors_jc42_exit(void)
 609 {
 610         i2c_del_driver(&jc42_driver);
 611 }
 612
 613 MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
 614 MODULE_DESCRIPTION("JC42 driver");
 615 MODULE_LICENSE("GPL");
 616
 617 module_init(sensors_jc42_init);
 618 module_exit(sensors_jc42_exit);