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 /* LM95241 registers */
  43 #define LM95241_REG_R_MAN_ID            0xFE
  44 #define LM95241_REG_R_CHIP_ID           0xFF
  45 #define LM95241_REG_R_STATUS            0x02
  46 #define LM95241_REG_RW_CONFIG           0x03
  47 #define LM95241_REG_RW_REM_FILTER       0x06
  48 #define LM95241_REG_RW_TRUTHERM         0x07
  49 #define LM95241_REG_W_ONE_SHOT          0x0F
  50 #define LM95241_REG_R_LOCAL_TEMPH       0x10
  51 #define LM95241_REG_R_REMOTE1_TEMPH     0x11
  52 #define LM95241_REG_R_REMOTE2_TEMPH     0x12
  53 #define LM95241_REG_R_LOCAL_TEMPL       0x20
  54 #define LM95241_REG_R_REMOTE1_TEMPL     0x21
  55 #define LM95241_REG_R_REMOTE2_TEMPL     0x22
  56 #define LM95241_REG_RW_REMOTE_MODEL     0x30
  57
  58 /* LM95241 specific bitfields */
  59 #define CFG_STOP 0x40
  60 #define CFG_CR0076 0x00
  61 #define CFG_CR0182 0x10
  62 #define CFG_CR1000 0x20
  63 #define CFG_CR2700 0x30
  64 #define R1MS_SHIFT 0
  65 #define R2MS_SHIFT 2
  66 #define R1MS_MASK (0x01 << (R1MS_SHIFT))
  67 #define R2MS_MASK (0x01 << (R2MS_SHIFT))
  68 #define R1DF_SHIFT 1
  69 #define R2DF_SHIFT 2
  70 #define R1DF_MASK (0x01 << (R1DF_SHIFT))
  71 #define R2DF_MASK (0x01 << (R2DF_SHIFT))
  72 #define R1FE_MASK 0x01
  73 #define R2FE_MASK 0x05
  74 #define TT1_SHIFT 0
  75 #define TT2_SHIFT 4
  76 #define TT_OFF 0
  77 #define TT_ON 1
  78 #define TT_MASK 7
  79 #define MANUFACTURER_ID 0x01
  80 #define DEFAULT_REVISION 0xA4
  81
  82 /* Conversions and various macros */
  83 #define TEMP_FROM_REG(val_h, val_l) (((val_h) & 0x80 ? (val_h) - 0x100 : \
  84     (val_h)) * 1000 + (val_l) * 1000 / 256)
  85
  86 /* Functions declaration */
  87 static void lm95241_init_client(struct i2c_client *client);
  88 static struct lm95241_data *lm95241_update_device(struct device *dev);
  89
  90 /* Client data (each client gets its own) */
  91 struct lm95241_data {
  92         struct device *hwmon_dev;
  93         struct mutex update_lock;
  94         unsigned long last_updated, interval; /* in jiffies */
  95         char valid; /* zero until following fields are valid */
  96         /* registers values */
  97         u8 local_h, local_l; /* local */
  98         u8 remote1_h, remote1_l; /* remote1 */
  99         u8 remote2_h, remote2_l; /* remote2 */
 100         u8 config, model, trutherm;
 101 };
 102
 103 /* Sysfs stuff */
 104 #define show_temp(value) \
 105 static ssize_t show_##value(struct device *dev, \
 106     struct device_attribute *attr, char *buf) \
 107 { \
 108         struct lm95241_data *data = lm95241_update_device(dev); \
 109         snprintf(buf, PAGE_SIZE - 1, "%d\n", \
 110                 TEMP_FROM_REG(data->value##_h, data->value##_l)); \
 111         return strlen(buf); \
 112 }
 113 show_temp(local);
 114 show_temp(remote1);
 115 show_temp(remote2);
 116
 117 static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
 118                          char *buf)
 119 {
 120         struct lm95241_data *data = lm95241_update_device(dev);
 121
 122         snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->interval / HZ);
 123         return strlen(buf);
 124 }
 125
 126 static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
 127                         const char *buf, size_t count)
 128 {
 129         struct i2c_client *client = to_i2c_client(dev);
 130         struct lm95241_data *data = i2c_get_clientdata(client);
 131         unsigned long val;
 132
 133         if (strict_strtoul(buf, 10, &val) < 0)
 134                 return -EINVAL;
 135
 136         data->interval = val * HZ / 1000;
 137
 138         return count;
 139 }
 140
 141 #define show_type(flag) \
 142 static ssize_t show_type##flag(struct device *dev, \
 143                                    struct device_attribute *attr, char *buf) \
 144 { \
 145         struct i2c_client *client = to_i2c_client(dev); \
 146         struct lm95241_data *data = i2c_get_clientdata(client); \
 147 \
 148         snprintf(buf, PAGE_SIZE - 1, \
 149                 data->model & R##flag##MS_MASK ? "1\n" : "2\n"); \
 150         return strlen(buf); \
 151 }
 152 show_type(1);
 153 show_type(2);
 154
 155 #define show_min(flag) \
 156 static ssize_t show_min##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->config & R##flag##DF_MASK ?       \
 164                 "-127000\n" : "0\n"); \
 165         return strlen(buf); \
 166 }
 167 show_min(1);
 168 show_min(2);
 169
 170 #define show_max(flag) \
 171 static ssize_t show_max##flag(struct device *dev, \
 172     struct device_attribute *attr, char *buf) \
 173 { \
 174         struct i2c_client *client = to_i2c_client(dev); \
 175         struct lm95241_data *data = i2c_get_clientdata(client); \
 176 \
 177         snprintf(buf, PAGE_SIZE - 1, \
 178                 data->config & R##flag##DF_MASK ? \
 179                 "127000\n" : "255000\n"); \
 180         return strlen(buf); \
 181 }
 182 show_max(1);
 183 show_max(2);
 184
 185 #define set_type(flag) \
 186 static ssize_t set_type##flag(struct device *dev, \
 187                                   struct device_attribute *attr, \
 188                                   const char *buf, size_t count) \
 189 { \
 190         struct i2c_client *client = to_i2c_client(dev); \
 191         struct lm95241_data *data = i2c_get_clientdata(client); \
 192 \
 193         long val; \
 194 \
 195         if (strict_strtol(buf, 10, &val) < 0) \
 196                 return -EINVAL; \
 197 \
 198         if ((val == 1) || (val == 2)) { \
 199 \
 200                 mutex_lock(&data->update_lock); \
 201 \
 202                 data->trutherm &= ~(TT_MASK << TT##flag##_SHIFT); \
 203                 if (val == 1) { \
 204                         data->model |= R##flag##MS_MASK; \
 205                         data->trutherm |= (TT_ON << TT##flag##_SHIFT); \
 206                 } \
 207                 else { \
 208                         data->model &= ~R##flag##MS_MASK; \
 209                         data->trutherm |= (TT_OFF << TT##flag##_SHIFT); \
 210                 } \
 211 \
 212                 data->valid = 0; \
 213 \
 214                 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL, \
 215                                           data->model); \
 216                 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, \
 217                                           data->trutherm); \
 218 \
 219                 mutex_unlock(&data->update_lock); \
 220 \
 221         } \
 222         return count; \
 223 }
 224 set_type(1);
 225 set_type(2);
 226
 227 #define set_min(flag) \
 228 static ssize_t set_min##flag(struct device *dev, \
 229         struct device_attribute *devattr, const char *buf, size_t count) \
 230 { \
 231         struct i2c_client *client = to_i2c_client(dev); \
 232         struct lm95241_data *data = i2c_get_clientdata(client); \
 233 \
 234         long val; \
 235 \
 236         if (strict_strtol(buf, 10, &val) < 0) \
 237                 return -EINVAL;\
 238 \
 239         mutex_lock(&data->update_lock); \
 240 \
 241         if (val < 0) \
 242                 data->config |= R##flag##DF_MASK; \
 243         else \
 244                 data->config &= ~R##flag##DF_MASK; \
 245 \
 246         data->valid = 0; \
 247 \
 248         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \
 249                 data->config); \
 250 \
 251         mutex_unlock(&data->update_lock); \
 252 \
 253         return count; \
 254 }
 255 set_min(1);
 256 set_min(2);
 257
 258 #define set_max(flag) \
 259 static ssize_t set_max##flag(struct device *dev, \
 260         struct device_attribute *devattr, const char *buf, size_t count) \
 261 { \
 262         struct i2c_client *client = to_i2c_client(dev); \
 263         struct lm95241_data *data = i2c_get_clientdata(client); \
 264 \
 265         long val; \
 266 \
 267         if (strict_strtol(buf, 10, &val) < 0) \
 268                 return -EINVAL; \
 269 \
 270         mutex_lock(&data->update_lock); \
 271 \
 272         if (val <= 127000) \
 273                 data->config |= R##flag##DF_MASK; \
 274         else \
 275                 data->config &= ~R##flag##DF_MASK; \
 276 \
 277         data->valid = 0; \
 278 \
 279         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \
 280                 data->config); \
 281 \
 282         mutex_unlock(&data->update_lock); \
 283 \
 284         return count; \
 285 }
 286 set_max(1);
 287 set_max(2);
 288
 289 static DEVICE_ATTR(temp1_input, S_IRUGO, show_local, NULL);
 290 static DEVICE_ATTR(temp2_input, S_IRUGO, show_remote1, NULL);
 291 static DEVICE_ATTR(temp3_input, S_IRUGO, show_remote2, NULL);
 292 static DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type1, set_type1);
 293 static DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type2, set_type2);
 294 static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min1, set_min1);
 295 static DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min2, set_min2);
 296 static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max1, set_max1);
 297 static DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max2, set_max2);
 298 static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
 299                    set_interval);
 300
 301 static struct attribute *lm95241_attributes[] = {
 302         &dev_attr_temp1_input.attr,
 303         &dev_attr_temp2_input.attr,
 304         &dev_attr_temp3_input.attr,
 305         &dev_attr_temp2_type.attr,
 306         &dev_attr_temp3_type.attr,
 307         &dev_attr_temp2_min.attr,
 308         &dev_attr_temp3_min.attr,
 309         &dev_attr_temp2_max.attr,
 310         &dev_attr_temp3_max.attr,
 311         &dev_attr_update_interval.attr,
 312         NULL
 313 };
 314
 315 static const struct attribute_group lm95241_group = {
 316         .attrs = lm95241_attributes,
 317 };
 318
 319 /* Return 0 if detection is successful, -ENODEV otherwise */
 320 static int lm95241_detect(struct i2c_client *new_client,
 321                           struct i2c_board_info *info)
 322 {
 323         struct i2c_adapter *adapter = new_client->adapter;
 324         int address = new_client->addr;
 325         const char *name;
 326
 327         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 328                 return -ENODEV;
 329
 330         if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID)
 331              == MANUFACTURER_ID)
 332          && (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID)
 333              >= DEFAULT_REVISION)) {
 334                 name = "lm95241";
 335         } else {
 336                 dev_dbg(&adapter->dev, "LM95241 detection failed at 0x%02x\n",
 337                         address);
 338                 return -ENODEV;
 339         }
 340
 341         /* Fill the i2c board info */
 342         strlcpy(info->type, name, I2C_NAME_SIZE);
 343         return 0;
 344 }
 345
 346 static int lm95241_probe(struct i2c_client *new_client,
 347                          const struct i2c_device_id *id)
 348 {
 349         struct lm95241_data *data;
 350         int err;
 351
 352         data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
 353         if (!data) {
 354                 err = -ENOMEM;
 355                 goto exit;
 356         }
 357
 358         i2c_set_clientdata(new_client, data);
 359         mutex_init(&data->update_lock);
 360
 361         /* Initialize the LM95241 chip */
 362         lm95241_init_client(new_client);
 363
 364         /* Register sysfs hooks */
 365         err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group);
 366         if (err)
 367                 goto exit_free;
 368
 369         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 370         if (IS_ERR(data->hwmon_dev)) {
 371                 err = PTR_ERR(data->hwmon_dev);
 372                 goto exit_remove_files;
 373         }
 374
 375         return 0;
 376
 377 exit_remove_files:
 378         sysfs_remove_group(&new_client->dev.kobj, &lm95241_group);
 379 exit_free:
 380         kfree(data);
 381 exit:
 382         return err;
 383 }
 384
 385 static void lm95241_init_client(struct i2c_client *client)
 386 {
 387         struct lm95241_data *data = i2c_get_clientdata(client);
 388
 389         data->interval = HZ;    /* 1 sec default */
 390         data->valid = 0;
 391         data->config = CFG_CR0076;
 392         data->model = 0;
 393         data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
 394
 395         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
 396                                   data->config);
 397         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
 398                                   R1FE_MASK | R2FE_MASK);
 399         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 400                                   data->trutherm);
 401         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 402                                   data->model);
 403 }
 404
 405 static int lm95241_remove(struct i2c_client *client)
 406 {
 407         struct lm95241_data *data = i2c_get_clientdata(client);
 408
 409         hwmon_device_unregister(data->hwmon_dev);
 410         sysfs_remove_group(&client->dev.kobj, &lm95241_group);
 411
 412         kfree(data);
 413         return 0;
 414 }
 415
 416 static struct lm95241_data *lm95241_update_device(struct device *dev)
 417 {
 418         struct i2c_client *client = to_i2c_client(dev);
 419         struct lm95241_data *data = i2c_get_clientdata(client);
 420
 421         mutex_lock(&data->update_lock);
 422
 423         if (time_after(jiffies, data->last_updated + data->interval) ||
 424             !data->valid) {
 425                 dev_dbg(&client->dev, "Updating lm95241 data.\n");
 426                 data->local_h =
 427                         i2c_smbus_read_byte_data(client,
 428                                                  LM95241_REG_R_LOCAL_TEMPH);
 429                 data->local_l =
 430                         i2c_smbus_read_byte_data(client,
 431                                                  LM95241_REG_R_LOCAL_TEMPL);
 432                 data->remote1_h =
 433                         i2c_smbus_read_byte_data(client,
 434                                                  LM95241_REG_R_REMOTE1_TEMPH);
 435                 data->remote1_l =
 436                         i2c_smbus_read_byte_data(client,
 437                                                  LM95241_REG_R_REMOTE1_TEMPL);
 438                 data->remote2_h =
 439                         i2c_smbus_read_byte_data(client,
 440                                                  LM95241_REG_R_REMOTE2_TEMPH);
 441                 data->remote2_l =
 442                         i2c_smbus_read_byte_data(client,
 443                                                  LM95241_REG_R_REMOTE2_TEMPL);
 444                 data->last_updated = jiffies;
 445                 data->valid = 1;
 446         }
 447
 448         mutex_unlock(&data->update_lock);
 449
 450         return data;
 451 }
 452
 453 /* Driver data (common to all clients) */
 454 static const struct i2c_device_id lm95241_id[] = {
 455         { "lm95241", 0 },
 456         { }
 457 };
 458 MODULE_DEVICE_TABLE(i2c, lm95241_id);
 459
 460 static struct i2c_driver lm95241_driver = {
 461         .class          = I2C_CLASS_HWMON,
 462         .driver = {
 463                 .name   = "lm95241",
 464         },
 465         .probe          = lm95241_probe,
 466         .remove         = lm95241_remove,
 467         .id_table       = lm95241_id,
 468         .detect         = lm95241_detect,
 469         .address_list   = normal_i2c,
 470 };
 471
 472 static int __init sensors_lm95241_init(void)
 473 {
 474         return i2c_add_driver(&lm95241_driver);
 475 }
 476
 477 static void __exit sensors_lm95241_exit(void)
 478 {
 479         i2c_del_driver(&lm95241_driver);
 480 }
 481
 482 MODULE_AUTHOR("Davide Rizzo <elpa-rizzo@gmail.com>");
 483 MODULE_DESCRIPTION("LM95241 sensor driver");
 484 MODULE_LICENSE("GPL");
 485
 486 module_init(sensors_lm95241_init);
 487 module_exit(sensors_lm95241_exit);