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 ATMEL_MANID             0x001f  /* Atmel */
  68 #define MAX_MANID               0x004d  /* Maxim */
  69 #define IDT_MANID               0x00b3  /* IDT */
  70 #define MCP_MANID               0x0054  /* Microchip */
  71 #define NXP_MANID               0x1131  /* NXP Semiconductors */
  72 #define ONS_MANID               0x1b09  /* ON Semiconductor */
  73 #define STM_MANID               0x104a  /* ST Microelectronics */
  74
  75 /* Supported chips */
  76
  77 /* Analog Devices */
  78 #define ADT7408_DEVID           0x0801
  79 #define ADT7408_DEVID_MASK      0xffff
  80
  81 /* Atmel */
  82 #define AT30TS00_DEVID          0x8201
  83 #define AT30TS00_DEVID_MASK     0xffff
  84
  85 /* IDT */
  86 #define TS3000B3_DEVID          0x2903  /* Also matches TSE2002B3 */
  87 #define TS3000B3_DEVID_MASK     0xffff
  88
  89 #define TS3000GB2_DEVID         0x2912  /* Also matches TSE2002GB2 */
  90 #define TS3000GB2_DEVID_MASK    0xffff
  91
  92 /* Maxim */
  93 #define MAX6604_DEVID           0x3e00
  94 #define MAX6604_DEVID_MASK      0xffff
  95
  96 /* Microchip */
  97 #define MCP9804_DEVID           0x0200
  98 #define MCP9804_DEVID_MASK      0xfffc
  99
 100 #define MCP98242_DEVID          0x2000
 101 #define MCP98242_DEVID_MASK     0xfffc
 102
 103 #define MCP98243_DEVID          0x2100
 104 #define MCP98243_DEVID_MASK     0xfffc
 105
 106 #define MCP9843_DEVID           0x0000  /* Also matches mcp9805 */
 107 #define MCP9843_DEVID_MASK      0xfffe
 108
 109 /* NXP */
 110 #define SE97_DEVID              0xa200
 111 #define SE97_DEVID_MASK         0xfffc
 112
 113 #define SE98_DEVID              0xa100
 114 #define SE98_DEVID_MASK         0xfffc
 115
 116 /* ON Semiconductor */
 117 #define CAT6095_DEVID           0x0800  /* Also matches CAT34TS02 */
 118 #define CAT6095_DEVID_MASK      0xffe0
 119
 120 /* ST Microelectronics */
 121 #define STTS424_DEVID           0x0101
 122 #define STTS424_DEVID_MASK      0xffff
 123
 124 #define STTS424E_DEVID          0x0000
 125 #define STTS424E_DEVID_MASK     0xfffe
 126
 127 #define STTS2002_DEVID          0x0300
 128 #define STTS2002_DEVID_MASK     0xffff
 129
 130 #define STTS3000_DEVID          0x0200
 131 #define STTS3000_DEVID_MASK     0xffff
 132
 133 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
 134
 135 struct jc42_chips {
 136         u16 manid;
 137         u16 devid;
 138         u16 devid_mask;
 139 };
 140
 141 static struct jc42_chips jc42_chips[] = {
 142         { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
 143         { ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
 144         { IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
 145         { IDT_MANID, TS3000GB2_DEVID, TS3000GB2_DEVID_MASK },
 146         { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
 147         { MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
 148         { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
 149         { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
 150         { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
 151         { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
 152         { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
 153         { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
 154         { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
 155         { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
 156         { STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
 157         { STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
 158 };
 159
 160 /* Each client has this additional data */
 161 struct jc42_data {
 162         struct device   *hwmon_dev;
 163         struct mutex    update_lock;    /* protect register access */
 164         bool            extended;       /* true if extended range supported */
 165         bool            valid;
 166         unsigned long   last_updated;   /* In jiffies */
 167         u16             orig_config;    /* original configuration */
 168         u16             config;         /* current configuration */
 169         u16             temp_input;     /* Temperatures */
 170         u16             temp_crit;
 171         u16             temp_min;
 172         u16             temp_max;
 173 };
 174
 175 static int jc42_probe(struct i2c_client *client,
 176                       const struct i2c_device_id *id);
 177 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info);
 178 static int jc42_remove(struct i2c_client *client);
 179 static int jc42_read_value(struct i2c_client *client, u8 reg);
 180 static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value);
 181
 182 static struct jc42_data *jc42_update_device(struct device *dev);
 183
 184 static const struct i2c_device_id jc42_id[] = {
 185         { "adt7408", 0 },
 186         { "at30ts00", 0 },
 187         { "cat94ts02", 0 },
 188         { "cat6095", 0 },
 189         { "jc42", 0 },
 190         { "max6604", 0 },
 191         { "mcp9804", 0 },
 192         { "mcp9805", 0 },
 193         { "mcp98242", 0 },
 194         { "mcp98243", 0 },
 195         { "mcp9843", 0 },
 196         { "se97", 0 },
 197         { "se97b", 0 },
 198         { "se98", 0 },
 199         { "stts424", 0 },
 200         { "stts2002", 0 },
 201         { "stts3000", 0 },
 202         { "tse2002", 0 },
 203         { "ts3000", 0 },
 204         { }
 205 };
 206 MODULE_DEVICE_TABLE(i2c, jc42_id);
 207
 208 #ifdef CONFIG_PM
 209
 210 static int jc42_suspend(struct device *dev)
 211 {
 212         struct i2c_client *client = to_i2c_client(dev);
 213         struct jc42_data *data = i2c_get_clientdata(client);
 214
 215         data->config |= JC42_CFG_SHUTDOWN;
 216         jc42_write_value(client, JC42_REG_CONFIG, data->config);
 217         return 0;
 218 }
 219
 220 static int jc42_resume(struct device *dev)
 221 {
 222         struct i2c_client *client = to_i2c_client(dev);
 223         struct jc42_data *data = i2c_get_clientdata(client);
 224
 225         data->config &= ~JC42_CFG_SHUTDOWN;
 226         jc42_write_value(client, JC42_REG_CONFIG, data->config);
 227         return 0;
 228 }
 229
 230 static const struct dev_pm_ops jc42_dev_pm_ops = {
 231         .suspend = jc42_suspend,
 232         .resume = jc42_resume,
 233 };
 234
 235 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
 236 #else
 237 #define JC42_DEV_PM_OPS NULL
 238 #endif /* CONFIG_PM */
 239
 240 /* This is the driver that will be inserted */
 241 static struct i2c_driver jc42_driver = {
 242         .class          = I2C_CLASS_SPD,
 243         .driver = {
 244                 .name   = "jc42",
 245                 .pm = JC42_DEV_PM_OPS,
 246         },
 247         .probe          = jc42_probe,
 248         .remove         = jc42_remove,
 249         .id_table       = jc42_id,
 250         .detect         = jc42_detect,
 251         .address_list   = normal_i2c,
 252 };
 253
 254 #define JC42_TEMP_MIN_EXTENDED  (-40000)
 255 #define JC42_TEMP_MIN           0
 256 #define JC42_TEMP_MAX           125000
 257
 258 static u16 jc42_temp_to_reg(int temp, bool extended)
 259 {
 260         int ntemp = SENSORS_LIMIT(temp,
 261                                   extended ? JC42_TEMP_MIN_EXTENDED :
 262                                   JC42_TEMP_MIN, JC42_TEMP_MAX);
 263
 264         /* convert from 0.001 to 0.0625 resolution */
 265         return (ntemp * 2 / 125) & 0x1fff;
 266 }
 267
 268 static int jc42_temp_from_reg(s16 reg)
 269 {
 270         reg &= 0x1fff;
 271
 272         /* sign extend register */
 273         if (reg & 0x1000)
 274                 reg |= 0xf000;
 275
 276         /* convert from 0.0625 to 0.001 resolution */
 277         return reg * 125 / 2;
 278 }
 279
 280 /* sysfs stuff */
 281
 282 /* read routines for temperature limits */
 283 #define show(value)     \
 284 static ssize_t show_##value(struct device *dev,                         \
 285                             struct device_attribute *attr,              \
 286                             char *buf)                                  \
 287 {                                                                       \
 288         struct jc42_data *data = jc42_update_device(dev);               \
 289         if (IS_ERR(data))                                               \
 290                 return PTR_ERR(data);                                   \
 291         return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value));   \
 292 }
 293
 294 show(temp_input);
 295 show(temp_crit);
 296 show(temp_min);
 297 show(temp_max);
 298
 299 /* read routines for hysteresis values */
 300 static ssize_t show_temp_crit_hyst(struct device *dev,
 301                                    struct device_attribute *attr, char *buf)
 302 {
 303         struct jc42_data *data = jc42_update_device(dev);
 304         int temp, hyst;
 305
 306         if (IS_ERR(data))
 307                 return PTR_ERR(data);
 308
 309         temp = jc42_temp_from_reg(data->temp_crit);
 310         hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
 311                                & JC42_CFG_HYST_MASK];
 312         return sprintf(buf, "%d\n", temp - hyst);
 313 }
 314
 315 static ssize_t show_temp_max_hyst(struct device *dev,
 316                                   struct device_attribute *attr, char *buf)
 317 {
 318         struct jc42_data *data = jc42_update_device(dev);
 319         int temp, hyst;
 320
 321         if (IS_ERR(data))
 322                 return PTR_ERR(data);
 323
 324         temp = jc42_temp_from_reg(data->temp_max);
 325         hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
 326                                & JC42_CFG_HYST_MASK];
 327         return sprintf(buf, "%d\n", temp - hyst);
 328 }
 329
 330 /* write routines */
 331 #define set(value, reg) \
 332 static ssize_t set_##value(struct device *dev,                          \
 333                            struct device_attribute *attr,               \
 334                            const char *buf, size_t count)               \
 335 {                                                                       \
 336         struct i2c_client *client = to_i2c_client(dev);                 \
 337         struct jc42_data *data = i2c_get_clientdata(client);            \
 338         int err, ret = count;                                           \
 339         long val;                                                       \
 340         if (strict_strtol(buf, 10, &val) < 0)                           \
 341                 return -EINVAL;                                         \
 342         mutex_lock(&data->update_lock);                                 \
 343         data->value = jc42_temp_to_reg(val, data->extended);            \
 344         err = jc42_write_value(client, reg, data->value);               \
 345         if (err < 0)                                                    \
 346                 ret = err;                                              \
 347         mutex_unlock(&data->update_lock);                               \
 348         return ret;                                                     \
 349 }
 350
 351 set(temp_min, JC42_REG_TEMP_LOWER);
 352 set(temp_max, JC42_REG_TEMP_UPPER);
 353 set(temp_crit, JC42_REG_TEMP_CRITICAL);
 354
 355 /* JC42.4 compliant chips only support four hysteresis values.
 356  * Pick best choice and go from there. */
 357 static ssize_t set_temp_crit_hyst(struct device *dev,
 358                                   struct device_attribute *attr,
 359                                   const char *buf, size_t count)
 360 {
 361         struct i2c_client *client = to_i2c_client(dev);
 362         struct jc42_data *data = i2c_get_clientdata(client);
 363         unsigned long val;
 364         int diff, hyst;
 365         int err;
 366         int ret = count;
 367
 368         if (strict_strtoul(buf, 10, &val) < 0)
 369                 return -EINVAL;
 370
 371         diff = jc42_temp_from_reg(data->temp_crit) - val;
 372         hyst = 0;
 373         if (diff > 0) {
 374                 if (diff < 2250)
 375                         hyst = 1;       /* 1.5 degrees C */
 376                 else if (diff < 4500)
 377                         hyst = 2;       /* 3.0 degrees C */
 378                 else
 379                         hyst = 3;       /* 6.0 degrees C */
 380         }
 381
 382         mutex_lock(&data->update_lock);
 383         data->config = (data->config
 384                         & ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT))
 385           | (hyst << JC42_CFG_HYST_SHIFT);
 386         err = jc42_write_value(client, JC42_REG_CONFIG, data->config);
 387         if (err < 0)
 388                 ret = err;
 389         mutex_unlock(&data->update_lock);
 390         return ret;
 391 }
 392
 393 static ssize_t show_alarm(struct device *dev,
 394                           struct device_attribute *attr, char *buf)
 395 {
 396         u16 bit = to_sensor_dev_attr(attr)->index;
 397         struct jc42_data *data = jc42_update_device(dev);
 398         u16 val;
 399
 400         if (IS_ERR(data))
 401                 return PTR_ERR(data);
 402
 403         val = data->temp_input;
 404         if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
 405                 val = 0;
 406         return sprintf(buf, "%u\n", (val >> bit) & 1);
 407 }
 408
 409 static DEVICE_ATTR(temp1_input, S_IRUGO,
 410                    show_temp_input, NULL);
 411 static DEVICE_ATTR(temp1_crit, S_IRUGO,
 412                    show_temp_crit, set_temp_crit);
 413 static DEVICE_ATTR(temp1_min, S_IRUGO,
 414                    show_temp_min, set_temp_min);
 415 static DEVICE_ATTR(temp1_max, S_IRUGO,
 416                    show_temp_max, set_temp_max);
 417
 418 static DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
 419                    show_temp_crit_hyst, set_temp_crit_hyst);
 420 static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
 421                    show_temp_max_hyst, NULL);
 422
 423 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
 424                           JC42_ALARM_CRIT_BIT);
 425 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
 426                           JC42_ALARM_MIN_BIT);
 427 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
 428                           JC42_ALARM_MAX_BIT);
 429
 430 static struct attribute *jc42_attributes[] = {
 431         &dev_attr_temp1_input.attr,
 432         &dev_attr_temp1_crit.attr,
 433         &dev_attr_temp1_min.attr,
 434         &dev_attr_temp1_max.attr,
 435         &dev_attr_temp1_crit_hyst.attr,
 436         &dev_attr_temp1_max_hyst.attr,
 437         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 438         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 439         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 440         NULL
 441 };
 442
 443 static mode_t jc42_attribute_mode(struct kobject *kobj,
 444                                   struct attribute *attr, int index)
 445 {
 446         struct device *dev = container_of(kobj, struct device, kobj);
 447         struct i2c_client *client = to_i2c_client(dev);
 448         struct jc42_data *data = i2c_get_clientdata(client);
 449         unsigned int config = data->config;
 450         bool readonly;
 451
 452         if (attr == &dev_attr_temp1_crit.attr)
 453                 readonly = config & JC42_CFG_TCRIT_LOCK;
 454         else if (attr == &dev_attr_temp1_min.attr ||
 455                  attr == &dev_attr_temp1_max.attr)
 456                 readonly = config & JC42_CFG_EVENT_LOCK;
 457         else if (attr == &dev_attr_temp1_crit_hyst.attr)
 458                 readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
 459         else
 460                 readonly = true;
 461
 462         return S_IRUGO | (readonly ? 0 : S_IWUSR);
 463 }
 464
 465 static const struct attribute_group jc42_group = {
 466         .attrs = jc42_attributes,
 467         .is_visible = jc42_attribute_mode,
 468 };
 469
 470 /* Return 0 if detection is successful, -ENODEV otherwise */
 471 static int jc42_detect(struct i2c_client *new_client,
 472                        struct i2c_board_info *info)
 473 {
 474         struct i2c_adapter *adapter = new_client->adapter;
 475         int i, config, cap, manid, devid;
 476
 477         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 478                                      I2C_FUNC_SMBUS_WORD_DATA))
 479                 return -ENODEV;
 480
 481         cap = jc42_read_value(new_client, JC42_REG_CAP);
 482         config = jc42_read_value(new_client, JC42_REG_CONFIG);
 483         manid = jc42_read_value(new_client, JC42_REG_MANID);
 484         devid = jc42_read_value(new_client, JC42_REG_DEVICEID);
 485
 486         if (cap < 0 || config < 0 || manid < 0 || devid < 0)
 487                 return -ENODEV;
 488
 489         if ((cap & 0xff00) || (config & 0xf800))
 490                 return -ENODEV;
 491
 492         for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
 493                 struct jc42_chips *chip = &jc42_chips[i];
 494                 if (manid == chip->manid &&
 495                     (devid & chip->devid_mask) == chip->devid) {
 496                         strlcpy(info->type, "jc42", I2C_NAME_SIZE);
 497                         return 0;
 498                 }
 499         }
 500         return -ENODEV;
 501 }
 502
 503 static int jc42_probe(struct i2c_client *new_client,
 504                       const struct i2c_device_id *id)
 505 {
 506         struct jc42_data *data;
 507         int config, cap, err;
 508
 509         data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL);
 510         if (!data) {
 511                 err = -ENOMEM;
 512                 goto exit;
 513         }
 514
 515         i2c_set_clientdata(new_client, data);
 516         mutex_init(&data->update_lock);
 517
 518         cap = jc42_read_value(new_client, JC42_REG_CAP);
 519         if (cap < 0) {
 520                 err = -EINVAL;
 521                 goto exit_free;
 522         }
 523         data->extended = !!(cap & JC42_CAP_RANGE);
 524
 525         config = jc42_read_value(new_client, JC42_REG_CONFIG);
 526         if (config < 0) {
 527                 err = -EINVAL;
 528                 goto exit_free;
 529         }
 530         data->orig_config = config;
 531         if (config & JC42_CFG_SHUTDOWN) {
 532                 config &= ~JC42_CFG_SHUTDOWN;
 533                 jc42_write_value(new_client, JC42_REG_CONFIG, config);
 534         }
 535         data->config = config;
 536
 537         /* Register sysfs hooks */
 538         err = sysfs_create_group(&new_client->dev.kobj, &jc42_group);
 539         if (err)
 540                 goto exit_free;
 541
 542         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 543         if (IS_ERR(data->hwmon_dev)) {
 544                 err = PTR_ERR(data->hwmon_dev);
 545                 goto exit_remove;
 546         }
 547
 548         return 0;
 549
 550 exit_remove:
 551         sysfs_remove_group(&new_client->dev.kobj, &jc42_group);
 552 exit_free:
 553         kfree(data);
 554 exit:
 555         return err;
 556 }
 557
 558 static int jc42_remove(struct i2c_client *client)
 559 {
 560         struct jc42_data *data = i2c_get_clientdata(client);
 561         hwmon_device_unregister(data->hwmon_dev);
 562         sysfs_remove_group(&client->dev.kobj, &jc42_group);
 563         if (data->config != data->orig_config)
 564                 jc42_write_value(client, JC42_REG_CONFIG, data->orig_config);
 565         kfree(data);
 566         return 0;
 567 }
 568
 569 /* All registers are word-sized. */
 570 static int jc42_read_value(struct i2c_client *client, u8 reg)
 571 {
 572         int ret = i2c_smbus_read_word_data(client, reg);
 573         if (ret < 0)
 574                 return ret;
 575         return swab16(ret);
 576 }
 577
 578 static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value)
 579 {
 580         return i2c_smbus_write_word_data(client, reg, swab16(value));
 581 }
 582
 583 static struct jc42_data *jc42_update_device(struct device *dev)
 584 {
 585         struct i2c_client *client = to_i2c_client(dev);
 586         struct jc42_data *data = i2c_get_clientdata(client);
 587         struct jc42_data *ret = data;
 588         int val;
 589
 590         mutex_lock(&data->update_lock);
 591
 592         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
 593                 val = jc42_read_value(client, JC42_REG_TEMP);
 594                 if (val < 0) {
 595                         ret = ERR_PTR(val);
 596                         goto abort;
 597                 }
 598                 data->temp_input = val;
 599
 600                 val = jc42_read_value(client, JC42_REG_TEMP_CRITICAL);
 601                 if (val < 0) {
 602                         ret = ERR_PTR(val);
 603                         goto abort;
 604                 }
 605                 data->temp_crit = val;
 606
 607                 val = jc42_read_value(client, JC42_REG_TEMP_LOWER);
 608                 if (val < 0) {
 609                         ret = ERR_PTR(val);
 610                         goto abort;
 611                 }
 612                 data->temp_min = val;
 613
 614                 val = jc42_read_value(client, JC42_REG_TEMP_UPPER);
 615                 if (val < 0) {
 616                         ret = ERR_PTR(val);
 617                         goto abort;
 618                 }
 619                 data->temp_max = val;
 620
 621                 data->last_updated = jiffies;
 622                 data->valid = true;
 623         }
 624 abort:
 625         mutex_unlock(&data->update_lock);
 626         return ret;
 627 }
 628
 629 static int __init sensors_jc42_init(void)
 630 {
 631         return i2c_add_driver(&jc42_driver);
 632 }
 633
 634 static void __exit sensors_jc42_exit(void)
 635 {
 636         i2c_del_driver(&jc42_driver);
 637 }
 638
 639 MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
 640 MODULE_DESCRIPTION("JC42 driver");
 641 MODULE_LICENSE("GPL");
 642
 643 module_init(sensors_jc42_init);
 644 module_exit(sensors_jc42_exit);