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
 180 static struct jc42_data *jc42_update_device(struct device *dev);
 181
 182 static const struct i2c_device_id jc42_id[] = {
 183         { "adt7408", 0 },
 184         { "at30ts00", 0 },
 185         { "cat94ts02", 0 },
 186         { "cat6095", 0 },
 187         { "jc42", 0 },
 188         { "max6604", 0 },
 189         { "mcp9804", 0 },
 190         { "mcp9805", 0 },
 191         { "mcp98242", 0 },
 192         { "mcp98243", 0 },
 193         { "mcp9843", 0 },
 194         { "se97", 0 },
 195         { "se97b", 0 },
 196         { "se98", 0 },
 197         { "stts424", 0 },
 198         { "stts2002", 0 },
 199         { "stts3000", 0 },
 200         { "tse2002", 0 },
 201         { "ts3000", 0 },
 202         { }
 203 };
 204 MODULE_DEVICE_TABLE(i2c, jc42_id);
 205
 206 #ifdef CONFIG_PM
 207
 208 static int jc42_suspend(struct device *dev)
 209 {
 210         struct i2c_client *client = to_i2c_client(dev);
 211         struct jc42_data *data = i2c_get_clientdata(client);
 212
 213         data->config |= JC42_CFG_SHUTDOWN;
 214         i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
 215         return 0;
 216 }
 217
 218 static int jc42_resume(struct device *dev)
 219 {
 220         struct i2c_client *client = to_i2c_client(dev);
 221         struct jc42_data *data = i2c_get_clientdata(client);
 222
 223         data->config &= ~JC42_CFG_SHUTDOWN;
 224         i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
 225         return 0;
 226 }
 227
 228 static const struct dev_pm_ops jc42_dev_pm_ops = {
 229         .suspend = jc42_suspend,
 230         .resume = jc42_resume,
 231 };
 232
 233 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
 234 #else
 235 #define JC42_DEV_PM_OPS NULL
 236 #endif /* CONFIG_PM */
 237
 238 /* This is the driver that will be inserted */
 239 static struct i2c_driver jc42_driver = {
 240         .class          = I2C_CLASS_SPD,
 241         .driver = {
 242                 .name   = "jc42",
 243                 .pm = JC42_DEV_PM_OPS,
 244         },
 245         .probe          = jc42_probe,
 246         .remove         = jc42_remove,
 247         .id_table       = jc42_id,
 248         .detect         = jc42_detect,
 249         .address_list   = normal_i2c,
 250 };
 251
 252 #define JC42_TEMP_MIN_EXTENDED  (-40000)
 253 #define JC42_TEMP_MIN           0
 254 #define JC42_TEMP_MAX           125000
 255
 256 static u16 jc42_temp_to_reg(int temp, bool extended)
 257 {
 258         int ntemp = SENSORS_LIMIT(temp,
 259                                   extended ? JC42_TEMP_MIN_EXTENDED :
 260                                   JC42_TEMP_MIN, JC42_TEMP_MAX);
 261
 262         /* convert from 0.001 to 0.0625 resolution */
 263         return (ntemp * 2 / 125) & 0x1fff;
 264 }
 265
 266 static int jc42_temp_from_reg(s16 reg)
 267 {
 268         reg &= 0x1fff;
 269
 270         /* sign extend register */
 271         if (reg & 0x1000)
 272                 reg |= 0xf000;
 273
 274         /* convert from 0.0625 to 0.001 resolution */
 275         return reg * 125 / 2;
 276 }
 277
 278 /* sysfs stuff */
 279
 280 /* read routines for temperature limits */
 281 #define show(value)     \
 282 static ssize_t show_##value(struct device *dev,                         \
 283                             struct device_attribute *attr,              \
 284                             char *buf)                                  \
 285 {                                                                       \
 286         struct jc42_data *data = jc42_update_device(dev);               \
 287         if (IS_ERR(data))                                               \
 288                 return PTR_ERR(data);                                   \
 289         return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value));   \
 290 }
 291
 292 show(temp_input);
 293 show(temp_crit);
 294 show(temp_min);
 295 show(temp_max);
 296
 297 /* read routines for hysteresis values */
 298 static ssize_t show_temp_crit_hyst(struct device *dev,
 299                                    struct device_attribute *attr, char *buf)
 300 {
 301         struct jc42_data *data = jc42_update_device(dev);
 302         int temp, hyst;
 303
 304         if (IS_ERR(data))
 305                 return PTR_ERR(data);
 306
 307         temp = jc42_temp_from_reg(data->temp_crit);
 308         hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
 309                                & JC42_CFG_HYST_MASK];
 310         return sprintf(buf, "%d\n", temp - hyst);
 311 }
 312
 313 static ssize_t show_temp_max_hyst(struct device *dev,
 314                                   struct device_attribute *attr, char *buf)
 315 {
 316         struct jc42_data *data = jc42_update_device(dev);
 317         int temp, hyst;
 318
 319         if (IS_ERR(data))
 320                 return PTR_ERR(data);
 321
 322         temp = jc42_temp_from_reg(data->temp_max);
 323         hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
 324                                & JC42_CFG_HYST_MASK];
 325         return sprintf(buf, "%d\n", temp - hyst);
 326 }
 327
 328 /* write routines */
 329 #define set(value, reg) \
 330 static ssize_t set_##value(struct device *dev,                          \
 331                            struct device_attribute *attr,               \
 332                            const char *buf, size_t count)               \
 333 {                                                                       \
 334         struct i2c_client *client = to_i2c_client(dev);                 \
 335         struct jc42_data *data = i2c_get_clientdata(client);            \
 336         int err, ret = count;                                           \
 337         long val;                                                       \
 338         if (kstrtol(buf, 10, &val) < 0)                         \
 339                 return -EINVAL;                                         \
 340         mutex_lock(&data->update_lock);                                 \
 341         data->value = jc42_temp_to_reg(val, data->extended);            \
 342         err = i2c_smbus_write_word_swapped(client, reg, data->value);   \
 343         if (err < 0)                                                    \
 344                 ret = err;                                              \
 345         mutex_unlock(&data->update_lock);                               \
 346         return ret;                                                     \
 347 }
 348
 349 set(temp_min, JC42_REG_TEMP_LOWER);
 350 set(temp_max, JC42_REG_TEMP_UPPER);
 351 set(temp_crit, JC42_REG_TEMP_CRITICAL);
 352
 353 /* JC42.4 compliant chips only support four hysteresis values.
 354  * Pick best choice and go from there. */
 355 static ssize_t set_temp_crit_hyst(struct device *dev,
 356                                   struct device_attribute *attr,
 357                                   const char *buf, size_t count)
 358 {
 359         struct i2c_client *client = to_i2c_client(dev);
 360         struct jc42_data *data = i2c_get_clientdata(client);
 361         unsigned long val;
 362         int diff, hyst;
 363         int err;
 364         int ret = count;
 365
 366         if (kstrtoul(buf, 10, &val) < 0)
 367                 return -EINVAL;
 368
 369         diff = jc42_temp_from_reg(data->temp_crit) - val;
 370         hyst = 0;
 371         if (diff > 0) {
 372                 if (diff < 2250)
 373                         hyst = 1;       /* 1.5 degrees C */
 374                 else if (diff < 4500)
 375                         hyst = 2;       /* 3.0 degrees C */
 376                 else
 377                         hyst = 3;       /* 6.0 degrees C */
 378         }
 379
 380         mutex_lock(&data->update_lock);
 381         data->config = (data->config
 382                         & ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT))
 383           | (hyst << JC42_CFG_HYST_SHIFT);
 384         err = i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
 385                                            data->config);
 386         if (err < 0)
 387                 ret = err;
 388         mutex_unlock(&data->update_lock);
 389         return ret;
 390 }
 391
 392 static ssize_t show_alarm(struct device *dev,
 393                           struct device_attribute *attr, char *buf)
 394 {
 395         u16 bit = to_sensor_dev_attr(attr)->index;
 396         struct jc42_data *data = jc42_update_device(dev);
 397         u16 val;
 398
 399         if (IS_ERR(data))
 400                 return PTR_ERR(data);
 401
 402         val = data->temp_input;
 403         if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
 404                 val = 0;
 405         return sprintf(buf, "%u\n", (val >> bit) & 1);
 406 }
 407
 408 static DEVICE_ATTR(temp1_input, S_IRUGO,
 409                    show_temp_input, NULL);
 410 static DEVICE_ATTR(temp1_crit, S_IRUGO,
 411                    show_temp_crit, set_temp_crit);
 412 static DEVICE_ATTR(temp1_min, S_IRUGO,
 413                    show_temp_min, set_temp_min);
 414 static DEVICE_ATTR(temp1_max, S_IRUGO,
 415                    show_temp_max, set_temp_max);
 416
 417 static DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
 418                    show_temp_crit_hyst, set_temp_crit_hyst);
 419 static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
 420                    show_temp_max_hyst, NULL);
 421
 422 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
 423                           JC42_ALARM_CRIT_BIT);
 424 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
 425                           JC42_ALARM_MIN_BIT);
 426 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
 427                           JC42_ALARM_MAX_BIT);
 428
 429 static struct attribute *jc42_attributes[] = {
 430         &dev_attr_temp1_input.attr,
 431         &dev_attr_temp1_crit.attr,
 432         &dev_attr_temp1_min.attr,
 433         &dev_attr_temp1_max.attr,
 434         &dev_attr_temp1_crit_hyst.attr,
 435         &dev_attr_temp1_max_hyst.attr,
 436         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 437         &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 438         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 439         NULL
 440 };
 441
 442 static umode_t jc42_attribute_mode(struct kobject *kobj,
 443                                   struct attribute *attr, int index)
 444 {
 445         struct device *dev = container_of(kobj, struct device, kobj);
 446         struct i2c_client *client = to_i2c_client(dev);
 447         struct jc42_data *data = i2c_get_clientdata(client);
 448         unsigned int config = data->config;
 449         bool readonly;
 450
 451         if (attr == &dev_attr_temp1_crit.attr)
 452                 readonly = config & JC42_CFG_TCRIT_LOCK;
 453         else if (attr == &dev_attr_temp1_min.attr ||
 454                  attr == &dev_attr_temp1_max.attr)
 455                 readonly = config & JC42_CFG_EVENT_LOCK;
 456         else if (attr == &dev_attr_temp1_crit_hyst.attr)
 457                 readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
 458         else
 459                 readonly = true;
 460
 461         return S_IRUGO | (readonly ? 0 : S_IWUSR);
 462 }
 463
 464 static const struct attribute_group jc42_group = {
 465         .attrs = jc42_attributes,
 466         .is_visible = jc42_attribute_mode,
 467 };
 468
 469 /* Return 0 if detection is successful, -ENODEV otherwise */
 470 static int jc42_detect(struct i2c_client *new_client,
 471                        struct i2c_board_info *info)
 472 {
 473         struct i2c_adapter *adapter = new_client->adapter;
 474         int i, config, cap, manid, devid;
 475
 476         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 477                                      I2C_FUNC_SMBUS_WORD_DATA))
 478                 return -ENODEV;
 479
 480         cap = i2c_smbus_read_word_swapped(new_client, JC42_REG_CAP);
 481         config = i2c_smbus_read_word_swapped(new_client, JC42_REG_CONFIG);
 482         manid = i2c_smbus_read_word_swapped(new_client, JC42_REG_MANID);
 483         devid = i2c_smbus_read_word_swapped(new_client, JC42_REG_DEVICEID);
 484
 485         if (cap < 0 || config < 0 || manid < 0 || devid < 0)
 486                 return -ENODEV;
 487
 488         if ((cap & 0xff00) || (config & 0xf800))
 489                 return -ENODEV;
 490
 491         for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
 492                 struct jc42_chips *chip = &jc42_chips[i];
 493                 if (manid == chip->manid &&
 494                     (devid & chip->devid_mask) == chip->devid) {
 495                         strlcpy(info->type, "jc42", I2C_NAME_SIZE);
 496                         return 0;
 497                 }
 498         }
 499         return -ENODEV;
 500 }
 501
 502 static int jc42_probe(struct i2c_client *new_client,
 503                       const struct i2c_device_id *id)
 504 {
 505         struct jc42_data *data;
 506         int config, cap, err;
 507
 508         data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL);
 509         if (!data) {
 510                 err = -ENOMEM;
 511                 goto exit;
 512         }
 513
 514         i2c_set_clientdata(new_client, data);
 515         mutex_init(&data->update_lock);
 516
 517         cap = i2c_smbus_read_word_swapped(new_client, JC42_REG_CAP);
 518         if (cap < 0) {
 519                 err = -EINVAL;
 520                 goto exit_free;
 521         }
 522         data->extended = !!(cap & JC42_CAP_RANGE);
 523
 524         config = i2c_smbus_read_word_swapped(new_client, JC42_REG_CONFIG);
 525         if (config < 0) {
 526                 err = -EINVAL;
 527                 goto exit_free;
 528         }
 529         data->orig_config = config;
 530         if (config & JC42_CFG_SHUTDOWN) {
 531                 config &= ~JC42_CFG_SHUTDOWN;
 532                 i2c_smbus_write_word_swapped(new_client, JC42_REG_CONFIG,
 533                                              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                 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
 565                                              data->orig_config);
 566         kfree(data);
 567         return 0;
 568 }
 569
 570 static struct jc42_data *jc42_update_device(struct device *dev)
 571 {
 572         struct i2c_client *client = to_i2c_client(dev);
 573         struct jc42_data *data = i2c_get_clientdata(client);
 574         struct jc42_data *ret = data;
 575         int val;
 576
 577         mutex_lock(&data->update_lock);
 578
 579         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
 580                 val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP);
 581                 if (val < 0) {
 582                         ret = ERR_PTR(val);
 583                         goto abort;
 584                 }
 585                 data->temp_input = val;
 586
 587                 val = i2c_smbus_read_word_swapped(client,
 588                                                   JC42_REG_TEMP_CRITICAL);
 589                 if (val < 0) {
 590                         ret = ERR_PTR(val);
 591                         goto abort;
 592                 }
 593                 data->temp_crit = val;
 594
 595                 val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_LOWER);
 596                 if (val < 0) {
 597                         ret = ERR_PTR(val);
 598                         goto abort;
 599                 }
 600                 data->temp_min = val;
 601
 602                 val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_UPPER);
 603                 if (val < 0) {
 604                         ret = ERR_PTR(val);
 605                         goto abort;
 606                 }
 607                 data->temp_max = val;
 608
 609                 data->last_updated = jiffies;
 610                 data->valid = true;
 611         }
 612 abort:
 613         mutex_unlock(&data->update_lock);
 614         return ret;
 615 }
 616
 617 module_i2c_driver(jc42_driver);
 618
 619 MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
 620 MODULE_DESCRIPTION("JC42 driver");
 621 MODULE_LICENSE("GPL");