drivers/hwmon/lm95241.c

   1 /*
   2  * lm95241.c - Part of lm_sensors, Linux kernel modules for hardware
   3  *             monitoring
   4  * Copyright (C) 2008 Davide Rizzo <elpa-rizzo@gmail.com>
   5  *
   6  * Based on the max1619 driver. The LM95241 is a sensor chip made by National
   7  *   Semiconductors.
   8  * It reports up to three temperatures (its own plus up to
   9  * two external ones). Complete datasheet can be
  10  * obtained from National's website at:
  11  *   http://www.national.com/ds.cgi/LM/LM95241.pdf
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  26  */
  27
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/slab.h>
  31 #include <linux/jiffies.h>
  32 #include <linux/i2c.h>
  33 #include <linux/hwmon.h>
  34 #include <linux/hwmon-sysfs.h>
  35 #include <linux/err.h>
  36 #include <linux/mutex.h>
  37 #include <linux/sysfs.h>
  38
  39 static const unsigned short normal_i2c[] = {
  40         0x19, 0x2a, 0x2b, I2C_CLIENT_END};
  41
  42 /* Insmod parameters */
  43 I2C_CLIENT_INSMOD_1(lm95241);
  44
  45 /* LM95241 registers */
  46 #define LM95241_REG_R_MAN_ID            0xFE
  47 #define LM95241_REG_R_CHIP_ID           0xFF
  48 #define LM95241_REG_R_STATUS            0x02
  49 #define LM95241_REG_RW_CONFIG           0x03
  50 #define LM95241_REG_RW_REM_FILTER       0x06
  51 #define LM95241_REG_RW_TRUTHERM         0x07
  52 #define LM95241_REG_W_ONE_SHOT          0x0F
  53 #define LM95241_REG_R_LOCAL_TEMPH       0x10
  54 #define LM95241_REG_R_REMOTE1_TEMPH     0x11
  55 #define LM95241_REG_R_REMOTE2_TEMPH     0x12
  56 #define LM95241_REG_R_LOCAL_TEMPL       0x20
  57 #define LM95241_REG_R_REMOTE1_TEMPL     0x21
  58 #define LM95241_REG_R_REMOTE2_TEMPL     0x22
  59 #define LM95241_REG_RW_REMOTE_MODEL     0x30
  60
  61 /* LM95241 specific bitfields */
  62 #define CFG_STOP 0x40
  63 #define CFG_CR0076 0x00
  64 #define CFG_CR0182 0x10
  65 #define CFG_CR1000 0x20
  66 #define CFG_CR2700 0x30
  67 #define R1MS_SHIFT 0
  68 #define R2MS_SHIFT 2
  69 #define R1MS_MASK (0x01 << (R1MS_SHIFT))
  70 #define R2MS_MASK (0x01 << (R2MS_SHIFT))
  71 #define R1DF_SHIFT 1
  72 #define R2DF_SHIFT 2
  73 #define R1DF_MASK (0x01 << (R1DF_SHIFT))
  74 #define R2DF_MASK (0x01 << (R2DF_SHIFT))
  75 #define R1FE_MASK 0x01
  76 #define R2FE_MASK 0x05
  77 #define TT1_SHIFT 0
  78 #define TT2_SHIFT 4
  79 #define TT_OFF 0
  80 #define TT_ON 1
  81 #define TT_MASK 7
  82 #define MANUFACTURER_ID 0x01
  83 #define DEFAULT_REVISION 0xA4
  84
  85 /* Conversions and various macros */
  86 #define TEMP_FROM_REG(val_h, val_l) (((val_h) & 0x80 ? (val_h) - 0x100 : \
  87     (val_h)) * 1000 + (val_l) * 1000 / 256)
  88
  89 /* Functions declaration */
  90 static int lm95241_attach_adapter(struct i2c_adapter *adapter);
  91 static int lm95241_detect(struct i2c_adapter *adapter, int address,
  92                           int kind);
  93 static void lm95241_init_client(struct i2c_client *client);
  94 static int lm95241_detach_client(struct i2c_client *client);
  95 static struct lm95241_data *lm95241_update_device(struct device *dev);
  96
  97 /* Driver data (common to all clients) */
  98 static struct i2c_driver lm95241_driver = {
  99         .driver = {
 100                 .name   = "lm95241",
 101         },
 102         .attach_adapter = lm95241_attach_adapter,
 103         .detach_client  = lm95241_detach_client,
 104 };
 105
 106 /* Client data (each client gets its own) */
 107 struct lm95241_data {
 108         struct i2c_client client;
 109         struct device *hwmon_dev;
 110         struct mutex update_lock;
 111         unsigned long last_updated, rate; /* in jiffies */
 112         char valid; /* zero until following fields are valid */
 113         /* registers values */
 114         u8 local_h, local_l; /* local */
 115         u8 remote1_h, remote1_l; /* remote1 */
 116         u8 remote2_h, remote2_l; /* remote2 */
 117         u8 config, model, trutherm;
 118 };
 119
 120 /* Sysfs stuff */
 121 #define show_temp(value) \
 122 static ssize_t show_##value(struct device *dev, \
 123     struct device_attribute *attr, char *buf) \
 124 { \
 125         struct lm95241_data *data = lm95241_update_device(dev); \
 126         snprintf(buf, PAGE_SIZE - 1, "%d\n", \
 127                 TEMP_FROM_REG(data->value##_h, data->value##_l)); \
 128         return strlen(buf); \
 129 }
 130 show_temp(local);
 131 show_temp(remote1);
 132 show_temp(remote2);
 133
 134 static ssize_t show_rate(struct device *dev, struct device_attribute *attr,
 135                          char *buf)
 136 {
 137         struct lm95241_data *data = lm95241_update_device(dev);
 138
 139         snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->rate / HZ);
 140         return strlen(buf);
 141 }
 142
 143 static ssize_t set_rate(struct device *dev, struct device_attribute *attr,
 144                         const char *buf, size_t count)
 145 {
 146         struct i2c_client *client = to_i2c_client(dev);
 147         struct lm95241_data *data = i2c_get_clientdata(client);
 148
 149         strict_strtol(buf, 10, &data->rate);
 150         data->rate = data->rate * HZ / 1000;
 151
 152         return count;
 153 }
 154
 155 #define show_type(flag) \
 156 static ssize_t show_type##flag(struct device *dev, \
 157                                    struct device_attribute *attr, char *buf) \
 158 { \
 159         struct i2c_client *client = to_i2c_client(dev); \
 160         struct lm95241_data *data = i2c_get_clientdata(client); \
 161 \
 162         snprintf(buf, PAGE_SIZE - 1, \
 163                 data->model & R##flag##MS_MASK ? "1\n" : "2\n"); \
 164         return strlen(buf); \
 165 }
 166 show_type(1);
 167 show_type(2);
 168
 169 #define show_min(flag) \
 170 static ssize_t show_min##flag(struct device *dev, \
 171     struct device_attribute *attr, char *buf) \
 172 { \
 173         struct i2c_client *client = to_i2c_client(dev); \
 174         struct lm95241_data *data = i2c_get_clientdata(client); \
 175 \
 176         snprintf(buf, PAGE_SIZE - 1, \
 177                 data->config & R##flag##DF_MASK ?       \
 178                 "-127000\n" : "0\n"); \
 179         return strlen(buf); \
 180 }
 181 show_min(1);
 182 show_min(2);
 183
 184 #define show_max(flag) \
 185 static ssize_t show_max##flag(struct device *dev, \
 186     struct device_attribute *attr, char *buf) \
 187 { \
 188         struct i2c_client *client = to_i2c_client(dev); \
 189         struct lm95241_data *data = i2c_get_clientdata(client); \
 190 \
 191         snprintf(buf, PAGE_SIZE - 1, \
 192                 data->config & R##flag##DF_MASK ? \
 193                 "127000\n" : "255000\n"); \
 194         return strlen(buf); \
 195 }
 196 show_max(1);
 197 show_max(2);
 198
 199 #define set_type(flag) \
 200 static ssize_t set_type##flag(struct device *dev, \
 201                                   struct device_attribute *attr, \
 202                                   const char *buf, size_t count) \
 203 { \
 204         struct i2c_client *client = to_i2c_client(dev); \
 205         struct lm95241_data *data = i2c_get_clientdata(client); \
 206 \
 207         long val; \
 208         strict_strtol(buf, 10, &val); \
 209 \
 210         if ((val == 1) || (val == 2)) { \
 211 \
 212                 mutex_lock(&data->update_lock); \
 213 \
 214                 data->trutherm &= ~(TT_MASK << TT##flag##_SHIFT); \
 215                 if (val == 1) { \
 216                         data->model |= R##flag##MS_MASK; \
 217                         data->trutherm |= (TT_ON << TT##flag##_SHIFT); \
 218                 } \
 219                 else { \
 220                         data->model &= ~R##flag##MS_MASK; \
 221                         data->trutherm |= (TT_OFF << TT##flag##_SHIFT); \
 222                 } \
 223 \
 224                 data->valid = 0; \
 225 \
 226                 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL, \
 227                                           data->model); \
 228                 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, \
 229                                           data->trutherm); \
 230 \
 231                 mutex_unlock(&data->update_lock); \
 232 \
 233         } \
 234         return count; \
 235 }
 236 set_type(1);
 237 set_type(2);
 238
 239 #define set_min(flag) \
 240 static ssize_t set_min##flag(struct device *dev, \
 241         struct device_attribute *devattr, const char *buf, size_t count) \
 242 { \
 243         struct i2c_client *client = to_i2c_client(dev); \
 244         struct lm95241_data *data = i2c_get_clientdata(client); \
 245 \
 246         long val; \
 247         strict_strtol(buf, 10, &val); \
 248 \
 249         mutex_lock(&data->update_lock); \
 250 \
 251         if (val < 0) \
 252                 data->config |= R##flag##DF_MASK; \
 253         else \
 254                 data->config &= ~R##flag##DF_MASK; \
 255 \
 256         data->valid = 0; \
 257 \
 258         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \
 259                 data->config); \
 260 \
 261         mutex_unlock(&data->update_lock); \
 262 \
 263         return count; \
 264 }
 265 set_min(1);
 266 set_min(2);
 267
 268 #define set_max(flag) \
 269 static ssize_t set_max##flag(struct device *dev, \
 270         struct device_attribute *devattr, const char *buf, size_t count) \
 271 { \
 272         struct i2c_client *client = to_i2c_client(dev); \
 273         struct lm95241_data *data = i2c_get_clientdata(client); \
 274 \
 275         long val; \
 276         strict_strtol(buf, 10, &val); \
 277 \
 278         mutex_lock(&data->update_lock); \
 279 \
 280         if (val <= 127000) \
 281                 data->config |= R##flag##DF_MASK; \
 282         else \
 283                 data->config &= ~R##flag##DF_MASK; \
 284 \
 285         data->valid = 0; \
 286 \
 287         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \
 288                 data->config); \
 289 \
 290         mutex_unlock(&data->update_lock); \
 291 \
 292         return count; \
 293 }
 294 set_max(1);
 295 set_max(2);
 296
 297 static DEVICE_ATTR(temp1_input, S_IRUGO, show_local, NULL);
 298 static DEVICE_ATTR(temp2_input, S_IRUGO, show_remote1, NULL);
 299 static DEVICE_ATTR(temp3_input, S_IRUGO, show_remote2, NULL);
 300 static DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type1, set_type1);
 301 static DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type2, set_type2);
 302 static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min1, set_min1);
 303 static DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min2, set_min2);
 304 static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max1, set_max1);
 305 static DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max2, set_max2);
 306 static DEVICE_ATTR(rate, S_IWUSR | S_IRUGO, show_rate, set_rate);
 307
 308 static struct attribute *lm95241_attributes[] = {
 309         &dev_attr_temp1_input.attr,
 310         &dev_attr_temp2_input.attr,
 311         &dev_attr_temp3_input.attr,
 312         &dev_attr_temp2_type.attr,
 313         &dev_attr_temp3_type.attr,
 314         &dev_attr_temp2_min.attr,
 315         &dev_attr_temp3_min.attr,
 316         &dev_attr_temp2_max.attr,
 317         &dev_attr_temp3_max.attr,
 318         &dev_attr_rate.attr,
 319         NULL
 320 };
 321
 322 static const struct attribute_group lm95241_group = {
 323         .attrs = lm95241_attributes,
 324 };
 325
 326 /* Init/exit code */
 327 static int lm95241_attach_adapter(struct i2c_adapter *adapter)
 328 {
 329         if (!(adapter->class & I2C_CLASS_HWMON))
 330                 return 0;
 331         return i2c_probe(adapter, &addr_data, lm95241_detect);
 332 }
 333
 334 /*
 335  * The following function does more than just detection. If detection
 336  * succeeds, it also registers the new chip.
 337  */
 338 static int lm95241_detect(struct i2c_adapter *adapter, int address, int kind)
 339 {
 340         struct i2c_client *new_client;
 341         struct lm95241_data *data;
 342         int err = 0;
 343         const char *name = "";
 344
 345         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 346                 goto exit;
 347
 348         data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
 349         if (!data) {
 350                 err = -ENOMEM;
 351                 goto exit;
 352         }
 353
 354         /* The common I2C client data is placed right before the
 355            LM95241-specific data. */
 356         new_client = &data->client;
 357         i2c_set_clientdata(new_client, data);
 358         new_client->addr = address;
 359         new_client->adapter = adapter;
 360         new_client->driver = &lm95241_driver;
 361         new_client->flags = 0;
 362
 363         /*
 364          * Now we do the remaining detection. A negative kind means that
 365          * the driver was loaded with no force parameter (default), so we
 366          * must both detect and identify the chip. A zero kind means that
 367          * the driver was loaded with the force parameter, the detection
 368          * step shall be skipped. A positive kind means that the driver
 369          * was loaded with the force parameter and a given kind of chip is
 370          * requested, so both the detection and the identification steps
 371          * are skipped.
 372          */
 373         if (kind < 0) { /* detection */
 374                 if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID)
 375                      != MANUFACTURER_ID)
 376                 || (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID)
 377                     < DEFAULT_REVISION)) {
 378                         dev_dbg(&adapter->dev,
 379                                 "LM95241 detection failed at 0x%02x.\n",
 380                                 address);
 381                         goto exit_free;
 382                 }
 383         }
 384
 385         if (kind <= 0) { /* identification */
 386                 if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID)
 387                      == MANUFACTURER_ID)
 388                 && (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID)
 389                     >= DEFAULT_REVISION)) {
 390
 391                         kind = lm95241;
 392
 393                         if (kind <= 0) { /* identification failed */
 394                                 dev_info(&adapter->dev, "Unsupported chip\n");
 395                                 goto exit_free;
 396                         }
 397                 }
 398         }
 399
 400         if (kind == lm95241)
 401                 name = "lm95241";
 402
 403         /* We can fill in the remaining client fields */
 404         strlcpy(new_client->name, name, I2C_NAME_SIZE);
 405         data->valid = 0;
 406         mutex_init(&data->update_lock);
 407
 408         /* Tell the I2C layer a new client has arrived */
 409         err = i2c_attach_client(new_client);
 410         if (err)
 411                 goto exit_free;
 412
 413         /* Initialize the LM95241 chip */
 414         lm95241_init_client(new_client);
 415
 416         /* Register sysfs hooks */
 417         err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group);
 418         if (err)
 419                 goto exit_detach;
 420
 421         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 422         if (IS_ERR(data->hwmon_dev)) {
 423                 err = PTR_ERR(data->hwmon_dev);
 424                 goto exit_remove_files;
 425         }
 426
 427         return 0;
 428
 429 exit_remove_files:
 430         sysfs_remove_group(&new_client->dev.kobj, &lm95241_group);
 431 exit_detach:
 432         i2c_detach_client(new_client);
 433 exit_free:
 434         kfree(data);
 435 exit:
 436         return err;
 437 }
 438
 439 static void lm95241_init_client(struct i2c_client *client)
 440 {
 441         struct lm95241_data *data = i2c_get_clientdata(client);
 442
 443         data->rate = HZ;    /* 1 sec default */
 444         data->valid = 0;
 445         data->config = CFG_CR0076;
 446         data->model = 0;
 447         data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
 448
 449         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
 450                                   data->config);
 451         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
 452                                   R1FE_MASK | R2FE_MASK);
 453         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 454                                   data->trutherm);
 455         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 456                                   data->model);
 457 }
 458
 459 static int lm95241_detach_client(struct i2c_client *client)
 460 {
 461         struct lm95241_data *data = i2c_get_clientdata(client);
 462         int err;
 463
 464         hwmon_device_unregister(data->hwmon_dev);
 465         sysfs_remove_group(&client->dev.kobj, &lm95241_group);
 466
 467         err = i2c_detach_client(client);
 468         if (err)
 469                 return err;
 470
 471         kfree(data);
 472         return 0;
 473 }
 474
 475 static struct lm95241_data *lm95241_update_device(struct device *dev)
 476 {
 477         struct i2c_client *client = to_i2c_client(dev);
 478         struct lm95241_data *data = i2c_get_clientdata(client);
 479
 480         mutex_lock(&data->update_lock);
 481
 482         if (time_after(jiffies, data->last_updated + data->rate) ||
 483             !data->valid) {
 484                 dev_dbg(&client->dev, "Updating lm95241 data.\n");
 485                 data->local_h =
 486                         i2c_smbus_read_byte_data(client,
 487                                                  LM95241_REG_R_LOCAL_TEMPH);
 488                 data->local_l =
 489                         i2c_smbus_read_byte_data(client,
 490                                                  LM95241_REG_R_LOCAL_TEMPL);
 491                 data->remote1_h =
 492                         i2c_smbus_read_byte_data(client,
 493                                                  LM95241_REG_R_REMOTE1_TEMPH);
 494                 data->remote1_l =
 495                         i2c_smbus_read_byte_data(client,
 496                                                  LM95241_REG_R_REMOTE1_TEMPL);
 497                 data->remote2_h =
 498                         i2c_smbus_read_byte_data(client,
 499                                                  LM95241_REG_R_REMOTE2_TEMPH);
 500                 data->remote2_l =
 501                         i2c_smbus_read_byte_data(client,
 502                                                  LM95241_REG_R_REMOTE2_TEMPL);
 503                 data->last_updated = jiffies;
 504                 data->valid = 1;
 505         }
 506
 507         mutex_unlock(&data->update_lock);
 508
 509         return data;
 510 }
 511
 512 static int __init sensors_lm95241_init(void)
 513 {
 514         return i2c_add_driver(&lm95241_driver);
 515 }
 516
 517 static void __exit sensors_lm95241_exit(void)
 518 {
 519         i2c_del_driver(&lm95241_driver);
 520 }
 521
 522 MODULE_AUTHOR("Davide Rizzo <elpa-rizzo@gmail.com>");
 523 MODULE_DESCRIPTION("LM95241 sensor driver");
 524 MODULE_LICENSE("GPL");
 525
 526 module_init(sensors_lm95241_init);
 527 module_exit(sensors_lm95241_exit);