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 unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
  52                                         0x29, 0x2a, 0x2b,
  53                                         0x4c, 0x4d, 0x4e,
  54                                         I2C_CLIENT_END };
  55
  56 /*
  57  * Insmod parameters
  58  */
  59
  60 I2C_CLIENT_INSMOD_2(lm83, lm82);
  61
  62 /*
  63  * The LM83 registers
  64  * Manufacturer ID is 0x01 for National Semiconductor.
  65  */
  66
  67 #define LM83_REG_R_MAN_ID               0xFE
  68 #define LM83_REG_R_CHIP_ID              0xFF
  69 #define LM83_REG_R_CONFIG               0x03
  70 #define LM83_REG_W_CONFIG               0x09
  71 #define LM83_REG_R_STATUS1              0x02
  72 #define LM83_REG_R_STATUS2              0x35
  73 #define LM83_REG_R_LOCAL_TEMP           0x00
  74 #define LM83_REG_R_LOCAL_HIGH           0x05
  75 #define LM83_REG_W_LOCAL_HIGH           0x0B
  76 #define LM83_REG_R_REMOTE1_TEMP         0x30
  77 #define LM83_REG_R_REMOTE1_HIGH         0x38
  78 #define LM83_REG_W_REMOTE1_HIGH         0x50
  79 #define LM83_REG_R_REMOTE2_TEMP         0x01
  80 #define LM83_REG_R_REMOTE2_HIGH         0x07
  81 #define LM83_REG_W_REMOTE2_HIGH         0x0D
  82 #define LM83_REG_R_REMOTE3_TEMP         0x31
  83 #define LM83_REG_R_REMOTE3_HIGH         0x3A
  84 #define LM83_REG_W_REMOTE3_HIGH         0x52
  85 #define LM83_REG_R_TCRIT                0x42
  86 #define LM83_REG_W_TCRIT                0x5A
  87
  88 /*
  89  * Conversions and various macros
  90  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
  91  */
  92
  93 #define TEMP_FROM_REG(val)      ((val) * 1000)
  94 #define TEMP_TO_REG(val)        ((val) <= -128000 ? -128 : \
  95                                  (val) >= 127000 ? 127 : \
  96                                  (val) < 0 ? ((val) - 500) / 1000 : \
  97                                  ((val) + 500) / 1000)
  98
  99 static const u8 LM83_REG_R_TEMP[] = {
 100         LM83_REG_R_LOCAL_TEMP,
 101         LM83_REG_R_REMOTE1_TEMP,
 102         LM83_REG_R_REMOTE2_TEMP,
 103         LM83_REG_R_REMOTE3_TEMP,
 104         LM83_REG_R_LOCAL_HIGH,
 105         LM83_REG_R_REMOTE1_HIGH,
 106         LM83_REG_R_REMOTE2_HIGH,
 107         LM83_REG_R_REMOTE3_HIGH,
 108         LM83_REG_R_TCRIT,
 109 };
 110
 111 static const u8 LM83_REG_W_HIGH[] = {
 112         LM83_REG_W_LOCAL_HIGH,
 113         LM83_REG_W_REMOTE1_HIGH,
 114         LM83_REG_W_REMOTE2_HIGH,
 115         LM83_REG_W_REMOTE3_HIGH,
 116         LM83_REG_W_TCRIT,
 117 };
 118
 119 /*
 120  * Functions declaration
 121  */
 122
 123 static int lm83_attach_adapter(struct i2c_adapter *adapter);
 124 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
 125 static int lm83_detach_client(struct i2c_client *client);
 126 static struct lm83_data *lm83_update_device(struct device *dev);
 127
 128 /*
 129  * Driver data (common to all clients)
 130  */
 131
 132 static struct i2c_driver lm83_driver = {
 133         .driver = {
 134                 .name   = "lm83",
 135         },
 136         .id             = I2C_DRIVERID_LM83,
 137         .attach_adapter = lm83_attach_adapter,
 138         .detach_client  = lm83_detach_client,
 139 };
 140
 141 /*
 142  * Client data (each client gets its own)
 143  */
 144
 145 struct lm83_data {
 146         struct i2c_client client;
 147         struct device *hwmon_dev;
 148         struct mutex update_lock;
 149         char valid; /* zero until following fields are valid */
 150         unsigned long last_updated; /* in jiffies */
 151
 152         /* registers values */
 153         s8 temp[9];     /* 0..3: input 1-4,
 154                            4..7: high limit 1-4,
 155                            8   : critical limit */
 156         u16 alarms; /* bitvector, combined */
 157 };
 158
 159 /*
 160  * Sysfs stuff
 161  */
 162
 163 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 164                          char *buf)
 165 {
 166         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 167         struct lm83_data *data = lm83_update_device(dev);
 168         return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 169 }
 170
 171 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 172                         const char *buf, size_t count)
 173 {
 174         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 175         struct i2c_client *client = to_i2c_client(dev);
 176         struct lm83_data *data = i2c_get_clientdata(client);
 177         long val = simple_strtol(buf, NULL, 10);
 178         int nr = attr->index;
 179
 180         mutex_lock(&data->update_lock);
 181         data->temp[nr] = TEMP_TO_REG(val);
 182         i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
 183                                   data->temp[nr]);
 184         mutex_unlock(&data->update_lock);
 185         return count;
 186 }
 187
 188 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
 189                            char *buf)
 190 {
 191         struct lm83_data *data = lm83_update_device(dev);
 192         return sprintf(buf, "%d\n", data->alarms);
 193 }
 194
 195 static ssize_t show_alarm(struct device *dev, struct device_attribute
 196                           *devattr, char *buf)
 197 {
 198         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 199         struct lm83_data *data = lm83_update_device(dev);
 200         int bitnr = attr->index;
 201
 202         return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
 203 }
 204
 205 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 206 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
 207 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
 208 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
 209 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
 210         set_temp, 4);
 211 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
 212         set_temp, 5);
 213 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
 214         set_temp, 6);
 215 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
 216         set_temp, 7);
 217 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
 218 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
 219 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
 220         set_temp, 8);
 221 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
 222
 223 /* Individual alarm files */
 224 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
 225 static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
 226 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 2);
 227 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4);
 228 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
 229 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 8);
 230 static SENSOR_DEVICE_ATTR(temp4_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
 231 static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_alarm, NULL, 10);
 232 static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 12);
 233 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 13);
 234 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 15);
 235 /* Raw alarm file for compatibility */
 236 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 237
 238 static struct attribute *lm83_attributes[] = {
 239         &sensor_dev_attr_temp1_input.dev_attr.attr,
 240         &sensor_dev_attr_temp3_input.dev_attr.attr,
 241         &sensor_dev_attr_temp1_max.dev_attr.attr,
 242         &sensor_dev_attr_temp3_max.dev_attr.attr,
 243         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 244         &sensor_dev_attr_temp3_crit.dev_attr.attr,
 245
 246         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 247         &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
 248         &sensor_dev_attr_temp3_fault.dev_attr.attr,
 249         &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 250         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 251         &dev_attr_alarms.attr,
 252         NULL
 253 };
 254
 255 static const struct attribute_group lm83_group = {
 256         .attrs = lm83_attributes,
 257 };
 258
 259 static struct attribute *lm83_attributes_opt[] = {
 260         &sensor_dev_attr_temp2_input.dev_attr.attr,
 261         &sensor_dev_attr_temp4_input.dev_attr.attr,
 262         &sensor_dev_attr_temp2_max.dev_attr.attr,
 263         &sensor_dev_attr_temp4_max.dev_attr.attr,
 264         &sensor_dev_attr_temp2_crit.dev_attr.attr,
 265         &sensor_dev_attr_temp4_crit.dev_attr.attr,
 266
 267         &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 268         &sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
 269         &sensor_dev_attr_temp4_fault.dev_attr.attr,
 270         &sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
 271         &sensor_dev_attr_temp2_fault.dev_attr.attr,
 272         &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 273         NULL
 274 };
 275
 276 static const struct attribute_group lm83_group_opt = {
 277         .attrs = lm83_attributes_opt,
 278 };
 279
 280 /*
 281  * Real code
 282  */
 283
 284 static int lm83_attach_adapter(struct i2c_adapter *adapter)
 285 {
 286         if (!(adapter->class & I2C_CLASS_HWMON))
 287                 return 0;
 288         return i2c_probe(adapter, &addr_data, lm83_detect);
 289 }
 290
 291 /*
 292  * The following function does more than just detection. If detection
 293  * succeeds, it also registers the new chip.
 294  */
 295 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
 296 {
 297         struct i2c_client *new_client;
 298         struct lm83_data *data;
 299         int err = 0;
 300         const char *name = "";
 301
 302         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 303                 goto exit;
 304
 305         if (!(data = kzalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
 306                 err = -ENOMEM;
 307                 goto exit;
 308         }
 309
 310         /* The common I2C client data is placed right after the
 311          * LM83-specific data. */
 312         new_client = &data->client;
 313         i2c_set_clientdata(new_client, data);
 314         new_client->addr = address;
 315         new_client->adapter = adapter;
 316         new_client->driver = &lm83_driver;
 317         new_client->flags = 0;
 318
 319         /* Now we do the detection and identification. A negative kind
 320          * means that the driver was loaded with no force parameter
 321          * (default), so we must both detect and identify the chip
 322          * (actually there is only one possible kind of chip for now, LM83).
 323          * A zero kind means that the driver was loaded with the force
 324          * parameter, the detection step shall be skipped. A positive kind
 325          * means that the driver was loaded with the force parameter and a
 326          * given kind of chip is requested, so both the detection and the
 327          * identification steps are skipped. */
 328
 329         /* Default to an LM83 if forced */
 330         if (kind == 0)
 331                 kind = lm83;
 332
 333         if (kind < 0) { /* detection */
 334                 if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
 335                     & 0xA8) != 0x00) ||
 336                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
 337                     & 0x48) != 0x00) ||
 338                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
 339                     & 0x41) != 0x00)) {
 340                         dev_dbg(&adapter->dev,
 341                             "LM83 detection failed at 0x%02x.\n", address);
 342                         goto exit_free;
 343                 }
 344         }
 345
 346         if (kind <= 0) { /* identification */
 347                 u8 man_id, chip_id;
 348
 349                 man_id = i2c_smbus_read_byte_data(new_client,
 350                     LM83_REG_R_MAN_ID);
 351                 chip_id = i2c_smbus_read_byte_data(new_client,
 352                     LM83_REG_R_CHIP_ID);
 353
 354                 if (man_id == 0x01) { /* National Semiconductor */
 355                         if (chip_id == 0x03) {
 356                                 kind = lm83;
 357                         } else
 358                         if (chip_id == 0x01) {
 359                                 kind = lm82;
 360                         }
 361                 }
 362
 363                 if (kind <= 0) { /* identification failed */
 364                         dev_info(&adapter->dev,
 365                             "Unsupported chip (man_id=0x%02X, "
 366                             "chip_id=0x%02X).\n", man_id, chip_id);
 367                         goto exit_free;
 368                 }
 369         }
 370
 371         if (kind == lm83) {
 372                 name = "lm83";
 373         } else
 374         if (kind == lm82) {
 375                 name = "lm82";
 376         }
 377
 378         /* We can fill in the remaining client fields */
 379         strlcpy(new_client->name, name, I2C_NAME_SIZE);
 380         data->valid = 0;
 381         mutex_init(&data->update_lock);
 382
 383         /* Tell the I2C layer a new client has arrived */
 384         if ((err = i2c_attach_client(new_client)))
 385                 goto exit_free;
 386
 387         /*
 388          * Register sysfs hooks
 389          * The LM82 can only monitor one external diode which is
 390          * at the same register as the LM83 temp3 entry - so we
 391          * declare 1 and 3 common, and then 2 and 4 only for the LM83.
 392          */
 393
 394         if ((err = sysfs_create_group(&new_client->dev.kobj, &lm83_group)))
 395                 goto exit_detach;
 396
 397         if (kind == lm83) {
 398                 if ((err = sysfs_create_group(&new_client->dev.kobj,
 399                                               &lm83_group_opt)))
 400                         goto exit_remove_files;
 401         }
 402
 403         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 404         if (IS_ERR(data->hwmon_dev)) {
 405                 err = PTR_ERR(data->hwmon_dev);
 406                 goto exit_remove_files;
 407         }
 408
 409         return 0;
 410
 411 exit_remove_files:
 412         sysfs_remove_group(&new_client->dev.kobj, &lm83_group);
 413         sysfs_remove_group(&new_client->dev.kobj, &lm83_group_opt);
 414 exit_detach:
 415         i2c_detach_client(new_client);
 416 exit_free:
 417         kfree(data);
 418 exit:
 419         return err;
 420 }
 421
 422 static int lm83_detach_client(struct i2c_client *client)
 423 {
 424         struct lm83_data *data = i2c_get_clientdata(client);
 425         int err;
 426
 427         hwmon_device_unregister(data->hwmon_dev);
 428         sysfs_remove_group(&client->dev.kobj, &lm83_group);
 429         sysfs_remove_group(&client->dev.kobj, &lm83_group_opt);
 430
 431         if ((err = i2c_detach_client(client)))
 432                 return err;
 433
 434         kfree(data);
 435         return 0;
 436 }
 437
 438 static struct lm83_data *lm83_update_device(struct device *dev)
 439 {
 440         struct i2c_client *client = to_i2c_client(dev);
 441         struct lm83_data *data = i2c_get_clientdata(client);
 442
 443         mutex_lock(&data->update_lock);
 444
 445         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 446                 int nr;
 447
 448                 dev_dbg(&client->dev, "Updating lm83 data.\n");
 449                 for (nr = 0; nr < 9; nr++) {
 450                         data->temp[nr] =
 451                             i2c_smbus_read_byte_data(client,
 452                             LM83_REG_R_TEMP[nr]);
 453                 }
 454                 data->alarms =
 455                     i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 456                     + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 457                     << 8);
 458
 459                 data->last_updated = jiffies;
 460                 data->valid = 1;
 461         }
 462
 463         mutex_unlock(&data->update_lock);
 464
 465         return data;
 466 }
 467
 468 static int __init sensors_lm83_init(void)
 469 {
 470         return i2c_add_driver(&lm83_driver);
 471 }
 472
 473 static void __exit sensors_lm83_exit(void)
 474 {
 475         i2c_del_driver(&lm83_driver);
 476 }
 477
 478 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 479 MODULE_DESCRIPTION("LM83 driver");
 480 MODULE_LICENSE("GPL");
 481
 482 module_init(sensors_lm83_init);
 483 module_exit(sensors_lm83_exit);