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, rate; /* 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_rate(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->rate / HZ);
 123         return strlen(buf);
 124 }
 125
 126 static ssize_t set_rate(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
 132         strict_strtol(buf, 10, &data->rate);
 133         data->rate = data->rate * HZ / 1000;
 134
 135         return count;
 136 }
 137
 138 #define show_type(flag) \
 139 static ssize_t show_type##flag(struct device *dev, \
 140                                    struct device_attribute *attr, char *buf) \
 141 { \
 142         struct i2c_client *client = to_i2c_client(dev); \
 143         struct lm95241_data *data = i2c_get_clientdata(client); \
 144 \
 145         snprintf(buf, PAGE_SIZE - 1, \
 146                 data->model & R##flag##MS_MASK ? "1\n" : "2\n"); \
 147         return strlen(buf); \
 148 }
 149 show_type(1);
 150 show_type(2);
 151
 152 #define show_min(flag) \
 153 static ssize_t show_min##flag(struct device *dev, \
 154     struct device_attribute *attr, char *buf) \
 155 { \
 156         struct i2c_client *client = to_i2c_client(dev); \
 157         struct lm95241_data *data = i2c_get_clientdata(client); \
 158 \
 159         snprintf(buf, PAGE_SIZE - 1, \
 160                 data->config & R##flag##DF_MASK ?       \
 161                 "-127000\n" : "0\n"); \
 162         return strlen(buf); \
 163 }
 164 show_min(1);
 165 show_min(2);
 166
 167 #define show_max(flag) \
 168 static ssize_t show_max##flag(struct device *dev, \
 169     struct device_attribute *attr, char *buf) \
 170 { \
 171         struct i2c_client *client = to_i2c_client(dev); \
 172         struct lm95241_data *data = i2c_get_clientdata(client); \
 173 \
 174         snprintf(buf, PAGE_SIZE - 1, \
 175                 data->config & R##flag##DF_MASK ? \
 176                 "127000\n" : "255000\n"); \
 177         return strlen(buf); \
 178 }
 179 show_max(1);
 180 show_max(2);
 181
 182 #define set_type(flag) \
 183 static ssize_t set_type##flag(struct device *dev, \
 184                                   struct device_attribute *attr, \
 185                                   const char *buf, size_t count) \
 186 { \
 187         struct i2c_client *client = to_i2c_client(dev); \
 188         struct lm95241_data *data = i2c_get_clientdata(client); \
 189 \
 190         long val; \
 191         strict_strtol(buf, 10, &val); \
 192 \
 193         if ((val == 1) || (val == 2)) { \
 194 \
 195                 mutex_lock(&data->update_lock); \
 196 \
 197                 data->trutherm &= ~(TT_MASK << TT##flag##_SHIFT); \
 198                 if (val == 1) { \
 199                         data->model |= R##flag##MS_MASK; \
 200                         data->trutherm |= (TT_ON << TT##flag##_SHIFT); \
 201                 } \
 202                 else { \
 203                         data->model &= ~R##flag##MS_MASK; \
 204                         data->trutherm |= (TT_OFF << TT##flag##_SHIFT); \
 205                 } \
 206 \
 207                 data->valid = 0; \
 208 \
 209                 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL, \
 210                                           data->model); \
 211                 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, \
 212                                           data->trutherm); \
 213 \
 214                 mutex_unlock(&data->update_lock); \
 215 \
 216         } \
 217         return count; \
 218 }
 219 set_type(1);
 220 set_type(2);
 221
 222 #define set_min(flag) \
 223 static ssize_t set_min##flag(struct device *dev, \
 224         struct device_attribute *devattr, const char *buf, size_t count) \
 225 { \
 226         struct i2c_client *client = to_i2c_client(dev); \
 227         struct lm95241_data *data = i2c_get_clientdata(client); \
 228 \
 229         long val; \
 230         strict_strtol(buf, 10, &val); \
 231 \
 232         mutex_lock(&data->update_lock); \
 233 \
 234         if (val < 0) \
 235                 data->config |= R##flag##DF_MASK; \
 236         else \
 237                 data->config &= ~R##flag##DF_MASK; \
 238 \
 239         data->valid = 0; \
 240 \
 241         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \
 242                 data->config); \
 243 \
 244         mutex_unlock(&data->update_lock); \
 245 \
 246         return count; \
 247 }
 248 set_min(1);
 249 set_min(2);
 250
 251 #define set_max(flag) \
 252 static ssize_t set_max##flag(struct device *dev, \
 253         struct device_attribute *devattr, const char *buf, size_t count) \
 254 { \
 255         struct i2c_client *client = to_i2c_client(dev); \
 256         struct lm95241_data *data = i2c_get_clientdata(client); \
 257 \
 258         long val; \
 259         strict_strtol(buf, 10, &val); \
 260 \
 261         mutex_lock(&data->update_lock); \
 262 \
 263         if (val <= 127000) \
 264                 data->config |= R##flag##DF_MASK; \
 265         else \
 266                 data->config &= ~R##flag##DF_MASK; \
 267 \
 268         data->valid = 0; \
 269 \
 270         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \
 271                 data->config); \
 272 \
 273         mutex_unlock(&data->update_lock); \
 274 \
 275         return count; \
 276 }
 277 set_max(1);
 278 set_max(2);
 279
 280 static DEVICE_ATTR(temp1_input, S_IRUGO, show_local, NULL);
 281 static DEVICE_ATTR(temp2_input, S_IRUGO, show_remote1, NULL);
 282 static DEVICE_ATTR(temp3_input, S_IRUGO, show_remote2, NULL);
 283 static DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type1, set_type1);
 284 static DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type2, set_type2);
 285 static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min1, set_min1);
 286 static DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min2, set_min2);
 287 static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max1, set_max1);
 288 static DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max2, set_max2);
 289 static DEVICE_ATTR(rate, S_IWUSR | S_IRUGO, show_rate, set_rate);
 290
 291 static struct attribute *lm95241_attributes[] = {
 292         &dev_attr_temp1_input.attr,
 293         &dev_attr_temp2_input.attr,
 294         &dev_attr_temp3_input.attr,
 295         &dev_attr_temp2_type.attr,
 296         &dev_attr_temp3_type.attr,
 297         &dev_attr_temp2_min.attr,
 298         &dev_attr_temp3_min.attr,
 299         &dev_attr_temp2_max.attr,
 300         &dev_attr_temp3_max.attr,
 301         &dev_attr_rate.attr,
 302         NULL
 303 };
 304
 305 static const struct attribute_group lm95241_group = {
 306         .attrs = lm95241_attributes,
 307 };
 308
 309 /* Return 0 if detection is successful, -ENODEV otherwise */
 310 static int lm95241_detect(struct i2c_client *new_client,
 311                           struct i2c_board_info *info)
 312 {
 313         struct i2c_adapter *adapter = new_client->adapter;
 314         int address = new_client->addr;
 315         const char *name;
 316
 317         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 318                 return -ENODEV;
 319
 320         if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID)
 321              == MANUFACTURER_ID)
 322          && (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID)
 323              >= DEFAULT_REVISION)) {
 324                 name = "lm95241";
 325         } else {
 326                 dev_dbg(&adapter->dev, "LM95241 detection failed at 0x%02x\n",
 327                         address);
 328                 return -ENODEV;
 329         }
 330
 331         /* Fill the i2c board info */
 332         strlcpy(info->type, name, I2C_NAME_SIZE);
 333         return 0;
 334 }
 335
 336 static int lm95241_probe(struct i2c_client *new_client,
 337                          const struct i2c_device_id *id)
 338 {
 339         struct lm95241_data *data;
 340         int err;
 341
 342         data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
 343         if (!data) {
 344                 err = -ENOMEM;
 345                 goto exit;
 346         }
 347
 348         i2c_set_clientdata(new_client, data);
 349         mutex_init(&data->update_lock);
 350
 351         /* Initialize the LM95241 chip */
 352         lm95241_init_client(new_client);
 353
 354         /* Register sysfs hooks */
 355         err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group);
 356         if (err)
 357                 goto exit_free;
 358
 359         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 360         if (IS_ERR(data->hwmon_dev)) {
 361                 err = PTR_ERR(data->hwmon_dev);
 362                 goto exit_remove_files;
 363         }
 364
 365         return 0;
 366
 367 exit_remove_files:
 368         sysfs_remove_group(&new_client->dev.kobj, &lm95241_group);
 369 exit_free:
 370         kfree(data);
 371 exit:
 372         return err;
 373 }
 374
 375 static void lm95241_init_client(struct i2c_client *client)
 376 {
 377         struct lm95241_data *data = i2c_get_clientdata(client);
 378
 379         data->rate = HZ;    /* 1 sec default */
 380         data->valid = 0;
 381         data->config = CFG_CR0076;
 382         data->model = 0;
 383         data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
 384
 385         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
 386                                   data->config);
 387         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
 388                                   R1FE_MASK | R2FE_MASK);
 389         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 390                                   data->trutherm);
 391         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 392                                   data->model);
 393 }
 394
 395 static int lm95241_remove(struct i2c_client *client)
 396 {
 397         struct lm95241_data *data = i2c_get_clientdata(client);
 398
 399         hwmon_device_unregister(data->hwmon_dev);
 400         sysfs_remove_group(&client->dev.kobj, &lm95241_group);
 401
 402         i2c_set_clientdata(client, NULL);
 403         kfree(data);
 404         return 0;
 405 }
 406
 407 static struct lm95241_data *lm95241_update_device(struct device *dev)
 408 {
 409         struct i2c_client *client = to_i2c_client(dev);
 410         struct lm95241_data *data = i2c_get_clientdata(client);
 411
 412         mutex_lock(&data->update_lock);
 413
 414         if (time_after(jiffies, data->last_updated + data->rate) ||
 415             !data->valid) {
 416                 dev_dbg(&client->dev, "Updating lm95241 data.\n");
 417                 data->local_h =
 418                         i2c_smbus_read_byte_data(client,
 419                                                  LM95241_REG_R_LOCAL_TEMPH);
 420                 data->local_l =
 421                         i2c_smbus_read_byte_data(client,
 422                                                  LM95241_REG_R_LOCAL_TEMPL);
 423                 data->remote1_h =
 424                         i2c_smbus_read_byte_data(client,
 425                                                  LM95241_REG_R_REMOTE1_TEMPH);
 426                 data->remote1_l =
 427                         i2c_smbus_read_byte_data(client,
 428                                                  LM95241_REG_R_REMOTE1_TEMPL);
 429                 data->remote2_h =
 430                         i2c_smbus_read_byte_data(client,
 431                                                  LM95241_REG_R_REMOTE2_TEMPH);
 432                 data->remote2_l =
 433                         i2c_smbus_read_byte_data(client,
 434                                                  LM95241_REG_R_REMOTE2_TEMPL);
 435                 data->last_updated = jiffies;
 436                 data->valid = 1;
 437         }
 438
 439         mutex_unlock(&data->update_lock);
 440
 441         return data;
 442 }
 443
 444 /* Driver data (common to all clients) */
 445 static const struct i2c_device_id lm95241_id[] = {
 446         { "lm95241", 0 },
 447         { }
 448 };
 449 MODULE_DEVICE_TABLE(i2c, lm95241_id);
 450
 451 static struct i2c_driver lm95241_driver = {
 452         .class          = I2C_CLASS_HWMON,
 453         .driver = {
 454                 .name   = "lm95241",
 455         },
 456         .probe          = lm95241_probe,
 457         .remove         = lm95241_remove,
 458         .id_table       = lm95241_id,
 459         .detect         = lm95241_detect,
 460         .address_list   = normal_i2c,
 461 };
 462
 463 static int __init sensors_lm95241_init(void)
 464 {
 465         return i2c_add_driver(&lm95241_driver);
 466 }
 467
 468 static void __exit sensors_lm95241_exit(void)
 469 {
 470         i2c_del_driver(&lm95241_driver);
 471 }
 472
 473 MODULE_AUTHOR("Davide Rizzo <elpa-rizzo@gmail.com>");
 474 MODULE_DESCRIPTION("LM95241 sensor driver");
 475 MODULE_LICENSE("GPL");
 476
 477 module_init(sensors_lm95241_init);
 478 module_exit(sensors_lm95241_exit);