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