drivers/hwmon/lm83.c

   1 /*
   2  * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
   3  *          monitoring
   4  * Copyright (C) 2003-2006  Jean Delvare <khali@linux-fr.org>
   5  *
   6  * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
   7  * a sensor chip made by National Semiconductor. It reports up to four
   8  * temperatures (its own plus up to three external ones) with a 1 deg
   9  * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
  10  * from National's website at:
  11  *   http://www.national.com/pf/LM/LM83.html
  12  * Since the datasheet omits to give the chip stepping code, I give it
  13  * here: 0x03 (at register 0xff).
  14  *
  15  * Also supports the LM82 temp sensor, which is basically a stripped down
  16  * model of the LM83.  Datasheet is here:
  17  * http://www.national.com/pf/LM/LM82.html
  18  *
  19  * This program is free software; you can redistribute it and/or modify
  20  * it under the terms of the GNU General Public License as published by
  21  * the Free Software Foundation; either version 2 of the License, or
  22  * (at your option) any later version.
  23  *
  24  * This program is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  * GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License
  30  * along with this program; if not, write to the Free Software
  31  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  32  */
  33
  34 #include <linux/module.h>
  35 #include <linux/init.h>
  36 #include <linux/slab.h>
  37 #include <linux/jiffies.h>
  38 #include <linux/i2c.h>
  39 #include <linux/hwmon-sysfs.h>
  40 #include <linux/hwmon.h>
  41 #include <linux/err.h>
  42 #include <linux/mutex.h>
  43 #include <linux/sysfs.h>
  44
  45 /*
  46  * Addresses to scan
  47  * Address is selected using 2 three-level pins, resulting in 9 possible
  48  * addresses.
  49  */
  50
  51 static const unsigned short normal_i2c[] = {
  52         0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
  53
  54 /*
  55  * Insmod parameters
  56  */
  57
  58 I2C_CLIENT_INSMOD_2(lm83, lm82);
  59
  60 /*
  61  * The LM83 registers
  62  * Manufacturer ID is 0x01 for National Semiconductor.
  63  */
  64
  65 #define LM83_REG_R_MAN_ID               0xFE
  66 #define LM83_REG_R_CHIP_ID              0xFF
  67 #define LM83_REG_R_CONFIG               0x03
  68 #define LM83_REG_W_CONFIG               0x09
  69 #define LM83_REG_R_STATUS1              0x02
  70 #define LM83_REG_R_STATUS2              0x35
  71 #define LM83_REG_R_LOCAL_TEMP           0x00
  72 #define LM83_REG_R_LOCAL_HIGH           0x05
  73 #define LM83_REG_W_LOCAL_HIGH           0x0B
  74 #define LM83_REG_R_REMOTE1_TEMP         0x30
  75 #define LM83_REG_R_REMOTE1_HIGH         0x38
  76 #define LM83_REG_W_REMOTE1_HIGH         0x50
  77 #define LM83_REG_R_REMOTE2_TEMP         0x01
  78 #define LM83_REG_R_REMOTE2_HIGH         0x07
  79 #define LM83_REG_W_REMOTE2_HIGH         0x0D
  80 #define LM83_REG_R_REMOTE3_TEMP         0x31
  81 #define LM83_REG_R_REMOTE3_HIGH         0x3A
  82 #define LM83_REG_W_REMOTE3_HIGH         0x52
  83 #define LM83_REG_R_TCRIT                0x42
  84 #define LM83_REG_W_TCRIT                0x5A
  85
  86 /*
  87  * Conversions and various macros
  88  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
  89  */
  90
  91 #define TEMP_FROM_REG(val)      ((val) * 1000)
  92 #define TEMP_TO_REG(val)        ((val) <= -128000 ? -128 : \
  93                                  (val) >= 127000 ? 127 : \
  94                                  (val) < 0 ? ((val) - 500) / 1000 : \
  95                                  ((val) + 500) / 1000)
  96
  97 static const u8 LM83_REG_R_TEMP[] = {
  98         LM83_REG_R_LOCAL_TEMP,
  99         LM83_REG_R_REMOTE1_TEMP,
 100         LM83_REG_R_REMOTE2_TEMP,
 101         LM83_REG_R_REMOTE3_TEMP,
 102         LM83_REG_R_LOCAL_HIGH,
 103         LM83_REG_R_REMOTE1_HIGH,
 104         LM83_REG_R_REMOTE2_HIGH,
 105         LM83_REG_R_REMOTE3_HIGH,
 106         LM83_REG_R_TCRIT,
 107 };
 108
 109 static const u8 LM83_REG_W_HIGH[] = {
 110         LM83_REG_W_LOCAL_HIGH,
 111         LM83_REG_W_REMOTE1_HIGH,
 112         LM83_REG_W_REMOTE2_HIGH,
 113         LM83_REG_W_REMOTE3_HIGH,
 114         LM83_REG_W_TCRIT,
 115 };
 116
 117 /*
 118  * Functions declaration
 119  */
 120
 121 static int lm83_attach_adapter(struct i2c_adapter *adapter);
 122 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
 123 static int lm83_detach_client(struct i2c_client *client);
 124 static struct lm83_data *lm83_update_device(struct device *dev);
 125
 126 /*
 127  * Driver data (common to all clients)
 128  */
 129
 130 static struct i2c_driver lm83_driver = {
 131         .driver = {
 132                 .name   = "lm83",
 133         },
 134         .attach_adapter = lm83_attach_adapter,
 135         .detach_client  = lm83_detach_client,
 136 };
 137
 138 /*
 139  * Client data (each client gets its own)
 140  */
 141
 142 struct lm83_data {
 143         struct i2c_client client;
 144         struct device *hwmon_dev;
 145         struct mutex update_lock;
 146         char valid; /* zero until following fields are valid */
 147         unsigned long last_updated; /* in jiffies */
 148
 149         /* registers values */
 150         s8 temp[9];     /* 0..3: input 1-4,
 151                            4..7: high limit 1-4,
 152                            8   : critical limit */
 153         u16 alarms; /* bitvector, combined */
 154 };
 155
 156 /*
 157  * Sysfs stuff
 158  */
 159
 160 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 161                          char *buf)
 162 {
 163         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 164         struct lm83_data *data = lm83_update_device(dev);
 165         return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 166 }
 167
 168 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 169                         const char *buf, size_t count)
 170 {
 171         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 172         struct i2c_client *client = to_i2c_client(dev);
 173         struct lm83_data *data = i2c_get_clientdata(client);
 174         long val = simple_strtol(buf, NULL, 10);
 175         int nr = attr->index;
 176
 177         mutex_lock(&data->update_lock);
 178         data->temp[nr] = TEMP_TO_REG(val);
 179         i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
 180                                   data->temp[nr]);
 181         mutex_unlock(&data->update_lock);
 182         return count;
 183 }
 184
 185 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
 186                            char *buf)
 187 {
 188         struct lm83_data *data = lm83_update_device(dev);
 189         return sprintf(buf, "%d\n", data->alarms);
 190 }
 191
 192 static ssize_t show_alarm(struct device *dev, struct device_attribute
 193                           *devattr, char *buf)
 194 {
 195         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 196         struct lm83_data *data = lm83_update_device(dev);
 197         int bitnr = attr->index;
 198
 199         return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
 200 }
 201
 202 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 203 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
 204 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
 205 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
 206 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
 207         set_temp, 4);
 208 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
 209         set_temp, 5);
 210 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
 211         set_temp, 6);
 212 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
 213         set_temp, 7);
 214 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
 215 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
 216 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
 217         set_temp, 8);
 218 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
 219
 220 /* Individual alarm files */
 221 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
 222 static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
 223 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 2);
 224 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4);
 225 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
 226 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 8);
 227 static SENSOR_DEVICE_ATTR(temp4_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
 228 static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_alarm, NULL, 10);
 229 static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 12);
 230 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 13);
 231 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 15);
 232 /* Raw alarm file for compatibility */
 233 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 234
 235 static struct attribute *lm83_attributes[] = {
 236         &sensor_dev_attr_temp1_input.dev_attr.attr,
 237         &sensor_dev_attr_temp3_input.dev_attr.attr,
 238         &sensor_dev_attr_temp1_max.dev_attr.attr,
 239         &sensor_dev_attr_temp3_max.dev_attr.attr,
 240         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 241         &sensor_dev_attr_temp3_crit.dev_attr.attr,
 242
 243         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 244         &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
 245         &sensor_dev_attr_temp3_fault.dev_attr.attr,
 246         &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 247         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 248         &dev_attr_alarms.attr,
 249         NULL
 250 };
 251
 252 static const struct attribute_group lm83_group = {
 253         .attrs = lm83_attributes,
 254 };
 255
 256 static struct attribute *lm83_attributes_opt[] = {
 257         &sensor_dev_attr_temp2_input.dev_attr.attr,
 258         &sensor_dev_attr_temp4_input.dev_attr.attr,
 259         &sensor_dev_attr_temp2_max.dev_attr.attr,
 260         &sensor_dev_attr_temp4_max.dev_attr.attr,
 261         &sensor_dev_attr_temp2_crit.dev_attr.attr,
 262         &sensor_dev_attr_temp4_crit.dev_attr.attr,
 263
 264         &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 265         &sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
 266         &sensor_dev_attr_temp4_fault.dev_attr.attr,
 267         &sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
 268         &sensor_dev_attr_temp2_fault.dev_attr.attr,
 269         &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 270         NULL
 271 };
 272
 273 static const struct attribute_group lm83_group_opt = {
 274         .attrs = lm83_attributes_opt,
 275 };
 276
 277 /*
 278  * Real code
 279  */
 280
 281 static int lm83_attach_adapter(struct i2c_adapter *adapter)
 282 {
 283         if (!(adapter->class & I2C_CLASS_HWMON))
 284                 return 0;
 285         return i2c_probe(adapter, &addr_data, lm83_detect);
 286 }
 287
 288 /*
 289  * The following function does more than just detection. If detection
 290  * succeeds, it also registers the new chip.
 291  */
 292 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
 293 {
 294         struct i2c_client *new_client;
 295         struct lm83_data *data;
 296         int err = 0;
 297         const char *name = "";
 298
 299         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 300                 goto exit;
 301
 302         if (!(data = kzalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
 303                 err = -ENOMEM;
 304                 goto exit;
 305         }
 306
 307         /* The common I2C client data is placed right after the
 308          * LM83-specific data. */
 309         new_client = &data->client;
 310         i2c_set_clientdata(new_client, data);
 311         new_client->addr = address;
 312         new_client->adapter = adapter;
 313         new_client->driver = &lm83_driver;
 314         new_client->flags = 0;
 315
 316         /* Now we do the detection and identification. A negative kind
 317          * means that the driver was loaded with no force parameter
 318          * (default), so we must both detect and identify the chip
 319          * (actually there is only one possible kind of chip for now, LM83).
 320          * A zero kind means that the driver was loaded with the force
 321          * parameter, the detection step shall be skipped. A positive kind
 322          * means that the driver was loaded with the force parameter and a
 323          * given kind of chip is requested, so both the detection and the
 324          * identification steps are skipped. */
 325
 326         /* Default to an LM83 if forced */
 327         if (kind == 0)
 328                 kind = lm83;
 329
 330         if (kind < 0) { /* detection */
 331                 if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
 332                     & 0xA8) != 0x00) ||
 333                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
 334                     & 0x48) != 0x00) ||
 335                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
 336                     & 0x41) != 0x00)) {
 337                         dev_dbg(&adapter->dev,
 338                             "LM83 detection failed at 0x%02x.\n", address);
 339                         goto exit_free;
 340                 }
 341         }
 342
 343         if (kind <= 0) { /* identification */
 344                 u8 man_id, chip_id;
 345
 346                 man_id = i2c_smbus_read_byte_data(new_client,
 347                     LM83_REG_R_MAN_ID);
 348                 chip_id = i2c_smbus_read_byte_data(new_client,
 349                     LM83_REG_R_CHIP_ID);
 350
 351                 if (man_id == 0x01) { /* National Semiconductor */
 352                         if (chip_id == 0x03) {
 353                                 kind = lm83;
 354                         } else
 355                         if (chip_id == 0x01) {
 356                                 kind = lm82;
 357                         }
 358                 }
 359
 360                 if (kind <= 0) { /* identification failed */
 361                         dev_info(&adapter->dev,
 362                             "Unsupported chip (man_id=0x%02X, "
 363                             "chip_id=0x%02X).\n", man_id, chip_id);
 364                         goto exit_free;
 365                 }
 366         }
 367
 368         if (kind == lm83) {
 369                 name = "lm83";
 370         } else
 371         if (kind == lm82) {
 372                 name = "lm82";
 373         }
 374
 375         /* We can fill in the remaining client fields */
 376         strlcpy(new_client->name, name, I2C_NAME_SIZE);
 377         data->valid = 0;
 378         mutex_init(&data->update_lock);
 379
 380         /* Tell the I2C layer a new client has arrived */
 381         if ((err = i2c_attach_client(new_client)))
 382                 goto exit_free;
 383
 384         /*
 385          * Register sysfs hooks
 386          * The LM82 can only monitor one external diode which is
 387          * at the same register as the LM83 temp3 entry - so we
 388          * declare 1 and 3 common, and then 2 and 4 only for the LM83.
 389          */
 390
 391         if ((err = sysfs_create_group(&new_client->dev.kobj, &lm83_group)))
 392                 goto exit_detach;
 393
 394         if (kind == lm83) {
 395                 if ((err = sysfs_create_group(&new_client->dev.kobj,
 396                                               &lm83_group_opt)))
 397                         goto exit_remove_files;
 398         }
 399
 400         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 401         if (IS_ERR(data->hwmon_dev)) {
 402                 err = PTR_ERR(data->hwmon_dev);
 403                 goto exit_remove_files;
 404         }
 405
 406         return 0;
 407
 408 exit_remove_files:
 409         sysfs_remove_group(&new_client->dev.kobj, &lm83_group);
 410         sysfs_remove_group(&new_client->dev.kobj, &lm83_group_opt);
 411 exit_detach:
 412         i2c_detach_client(new_client);
 413 exit_free:
 414         kfree(data);
 415 exit:
 416         return err;
 417 }
 418
 419 static int lm83_detach_client(struct i2c_client *client)
 420 {
 421         struct lm83_data *data = i2c_get_clientdata(client);
 422         int err;
 423
 424         hwmon_device_unregister(data->hwmon_dev);
 425         sysfs_remove_group(&client->dev.kobj, &lm83_group);
 426         sysfs_remove_group(&client->dev.kobj, &lm83_group_opt);
 427
 428         if ((err = i2c_detach_client(client)))
 429                 return err;
 430
 431         kfree(data);
 432         return 0;
 433 }
 434
 435 static struct lm83_data *lm83_update_device(struct device *dev)
 436 {
 437         struct i2c_client *client = to_i2c_client(dev);
 438         struct lm83_data *data = i2c_get_clientdata(client);
 439
 440         mutex_lock(&data->update_lock);
 441
 442         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 443                 int nr;
 444
 445                 dev_dbg(&client->dev, "Updating lm83 data.\n");
 446                 for (nr = 0; nr < 9; nr++) {
 447                         data->temp[nr] =
 448                             i2c_smbus_read_byte_data(client,
 449                             LM83_REG_R_TEMP[nr]);
 450                 }
 451                 data->alarms =
 452                     i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 453                     + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 454                     << 8);
 455
 456                 data->last_updated = jiffies;
 457                 data->valid = 1;
 458         }
 459
 460         mutex_unlock(&data->update_lock);
 461
 462         return data;
 463 }
 464
 465 static int __init sensors_lm83_init(void)
 466 {
 467         return i2c_add_driver(&lm83_driver);
 468 }
 469
 470 static void __exit sensors_lm83_exit(void)
 471 {
 472         i2c_del_driver(&lm83_driver);
 473 }
 474
 475 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 476 MODULE_DESCRIPTION("LM83 driver");
 477 MODULE_LICENSE("GPL");
 478
 479 module_init(sensors_lm83_init);
 480 module_exit(sensors_lm83_exit);