drivers/hwmon/lm83.c

   1 /*
   2  * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
   3  *          monitoring
   4  * Copyright (C) 2003-2005  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
  44 /*
  45  * Addresses to scan
  46  * Address is selected using 2 three-level pins, resulting in 9 possible
  47  * addresses.
  48  */
  49
  50 static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
  51                                         0x29, 0x2a, 0x2b,
  52                                         0x4c, 0x4d, 0x4e,
  53                                         I2C_CLIENT_END };
  54
  55 /*
  56  * Insmod parameters
  57  */
  58
  59 I2C_CLIENT_INSMOD_2(lm83, lm82);
  60
  61 /*
  62  * The LM83 registers
  63  * Manufacturer ID is 0x01 for National Semiconductor.
  64  */
  65
  66 #define LM83_REG_R_MAN_ID               0xFE
  67 #define LM83_REG_R_CHIP_ID              0xFF
  68 #define LM83_REG_R_CONFIG               0x03
  69 #define LM83_REG_W_CONFIG               0x09
  70 #define LM83_REG_R_STATUS1              0x02
  71 #define LM83_REG_R_STATUS2              0x35
  72 #define LM83_REG_R_LOCAL_TEMP           0x00
  73 #define LM83_REG_R_LOCAL_HIGH           0x05
  74 #define LM83_REG_W_LOCAL_HIGH           0x0B
  75 #define LM83_REG_R_REMOTE1_TEMP         0x30
  76 #define LM83_REG_R_REMOTE1_HIGH         0x38
  77 #define LM83_REG_W_REMOTE1_HIGH         0x50
  78 #define LM83_REG_R_REMOTE2_TEMP         0x01
  79 #define LM83_REG_R_REMOTE2_HIGH         0x07
  80 #define LM83_REG_W_REMOTE2_HIGH         0x0D
  81 #define LM83_REG_R_REMOTE3_TEMP         0x31
  82 #define LM83_REG_R_REMOTE3_HIGH         0x3A
  83 #define LM83_REG_W_REMOTE3_HIGH         0x52
  84 #define LM83_REG_R_TCRIT                0x42
  85 #define LM83_REG_W_TCRIT                0x5A
  86
  87 /*
  88  * Conversions and various macros
  89  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
  90  */
  91
  92 #define TEMP_FROM_REG(val)      ((val) * 1000)
  93 #define TEMP_TO_REG(val)        ((val) <= -128000 ? -128 : \
  94                                  (val) >= 127000 ? 127 : \
  95                                  (val) < 0 ? ((val) - 500) / 1000 : \
  96                                  ((val) + 500) / 1000)
  97
  98 static const u8 LM83_REG_R_TEMP[] = {
  99         LM83_REG_R_LOCAL_TEMP,
 100         LM83_REG_R_REMOTE1_TEMP,
 101         LM83_REG_R_REMOTE2_TEMP,
 102         LM83_REG_R_REMOTE3_TEMP,
 103         LM83_REG_R_LOCAL_HIGH,
 104         LM83_REG_R_REMOTE1_HIGH,
 105         LM83_REG_R_REMOTE2_HIGH,
 106         LM83_REG_R_REMOTE3_HIGH,
 107         LM83_REG_R_TCRIT,
 108 };
 109
 110 static const u8 LM83_REG_W_HIGH[] = {
 111         LM83_REG_W_LOCAL_HIGH,
 112         LM83_REG_W_REMOTE1_HIGH,
 113         LM83_REG_W_REMOTE2_HIGH,
 114         LM83_REG_W_REMOTE3_HIGH,
 115         LM83_REG_W_TCRIT,
 116 };
 117
 118 /*
 119  * Functions declaration
 120  */
 121
 122 static int lm83_attach_adapter(struct i2c_adapter *adapter);
 123 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
 124 static int lm83_detach_client(struct i2c_client *client);
 125 static struct lm83_data *lm83_update_device(struct device *dev);
 126
 127 /*
 128  * Driver data (common to all clients)
 129  */
 130
 131 static struct i2c_driver lm83_driver = {
 132         .driver = {
 133                 .name   = "lm83",
 134         },
 135         .id             = I2C_DRIVERID_LM83,
 136         .attach_adapter = lm83_attach_adapter,
 137         .detach_client  = lm83_detach_client,
 138 };
 139
 140 /*
 141  * Client data (each client gets its own)
 142  */
 143
 144 struct lm83_data {
 145         struct i2c_client client;
 146         struct class_device *class_dev;
 147         struct mutex update_lock;
 148         char valid; /* zero until following fields are valid */
 149         unsigned long last_updated; /* in jiffies */
 150
 151         /* registers values */
 152         s8 temp[9];     /* 0..3: input 1-4,
 153                            4..7: high limit 1-4,
 154                            8   : critical limit */
 155         u16 alarms; /* bitvector, combined */
 156 };
 157
 158 /*
 159  * Sysfs stuff
 160  */
 161
 162 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 163                          char *buf)
 164 {
 165         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 166         struct lm83_data *data = lm83_update_device(dev);
 167         return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 168 }
 169
 170 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 171                         const char *buf, size_t count)
 172 {
 173         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 174         struct i2c_client *client = to_i2c_client(dev);
 175         struct lm83_data *data = i2c_get_clientdata(client);
 176         long val = simple_strtol(buf, NULL, 10);
 177         int nr = attr->index;
 178
 179         mutex_lock(&data->update_lock);
 180         data->temp[nr] = TEMP_TO_REG(val);
 181         i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
 182                                   data->temp[nr]);
 183         mutex_unlock(&data->update_lock);
 184         return count;
 185 }
 186
 187 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
 188                            char *buf)
 189 {
 190         struct lm83_data *data = lm83_update_device(dev);
 191         return sprintf(buf, "%d\n", data->alarms);
 192 }
 193
 194 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 195 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
 196 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
 197 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
 198 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
 199         set_temp, 4);
 200 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
 201         set_temp, 5);
 202 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
 203         set_temp, 6);
 204 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
 205         set_temp, 7);
 206 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
 207 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
 208 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
 209         set_temp, 8);
 210 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
 211 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 212
 213 /*
 214  * Real code
 215  */
 216
 217 static int lm83_attach_adapter(struct i2c_adapter *adapter)
 218 {
 219         if (!(adapter->class & I2C_CLASS_HWMON))
 220                 return 0;
 221         return i2c_probe(adapter, &addr_data, lm83_detect);
 222 }
 223
 224 /*
 225  * The following function does more than just detection. If detection
 226  * succeeds, it also registers the new chip.
 227  */
 228 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
 229 {
 230         struct i2c_client *new_client;
 231         struct lm83_data *data;
 232         int err = 0;
 233         const char *name = "";
 234
 235         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 236                 goto exit;
 237
 238         if (!(data = kzalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
 239                 err = -ENOMEM;
 240                 goto exit;
 241         }
 242
 243         /* The common I2C client data is placed right after the
 244          * LM83-specific data. */
 245         new_client = &data->client;
 246         i2c_set_clientdata(new_client, data);
 247         new_client->addr = address;
 248         new_client->adapter = adapter;
 249         new_client->driver = &lm83_driver;
 250         new_client->flags = 0;
 251
 252         /* Now we do the detection and identification. A negative kind
 253          * means that the driver was loaded with no force parameter
 254          * (default), so we must both detect and identify the chip
 255          * (actually there is only one possible kind of chip for now, LM83).
 256          * A zero kind means that the driver was loaded with the force
 257          * parameter, the detection step shall be skipped. A positive kind
 258          * means that the driver was loaded with the force parameter and a
 259          * given kind of chip is requested, so both the detection and the
 260          * identification steps are skipped. */
 261
 262         /* Default to an LM83 if forced */
 263         if (kind == 0)
 264                 kind = lm83;
 265
 266         if (kind < 0) { /* detection */
 267                 if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
 268                     & 0xA8) != 0x00) ||
 269                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
 270                     & 0x48) != 0x00) ||
 271                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
 272                     & 0x41) != 0x00)) {
 273                         dev_dbg(&adapter->dev,
 274                             "LM83 detection failed at 0x%02x.\n", address);
 275                         goto exit_free;
 276                 }
 277         }
 278
 279         if (kind <= 0) { /* identification */
 280                 u8 man_id, chip_id;
 281
 282                 man_id = i2c_smbus_read_byte_data(new_client,
 283                     LM83_REG_R_MAN_ID);
 284                 chip_id = i2c_smbus_read_byte_data(new_client,
 285                     LM83_REG_R_CHIP_ID);
 286
 287                 if (man_id == 0x01) { /* National Semiconductor */
 288                         if (chip_id == 0x03) {
 289                                 kind = lm83;
 290                         } else
 291                         if (chip_id == 0x01) {
 292                                 kind = lm82;
 293                         }
 294                 }
 295
 296                 if (kind <= 0) { /* identification failed */
 297                         dev_info(&adapter->dev,
 298                             "Unsupported chip (man_id=0x%02X, "
 299                             "chip_id=0x%02X).\n", man_id, chip_id);
 300                         goto exit_free;
 301                 }
 302         }
 303
 304         if (kind == lm83) {
 305                 name = "lm83";
 306         } else
 307         if (kind == lm82) {
 308                 name = "lm82";
 309         }
 310
 311         /* We can fill in the remaining client fields */
 312         strlcpy(new_client->name, name, I2C_NAME_SIZE);
 313         data->valid = 0;
 314         mutex_init(&data->update_lock);
 315
 316         /* Tell the I2C layer a new client has arrived */
 317         if ((err = i2c_attach_client(new_client)))
 318                 goto exit_free;
 319
 320         /*
 321          * Initialize the LM83 chip
 322          * (Nothing to do for this one.)
 323          */
 324
 325         /* Register sysfs hooks */
 326         data->class_dev = hwmon_device_register(&new_client->dev);
 327         if (IS_ERR(data->class_dev)) {
 328                 err = PTR_ERR(data->class_dev);
 329                 goto exit_detach;
 330         }
 331
 332         /*
 333          * The LM82 can only monitor one external diode which is
 334          * at the same register as the LM83 temp3 entry - so we
 335          * declare 1 and 3 common, and then 2 and 4 only for the LM83.
 336          */
 337
 338         device_create_file(&new_client->dev,
 339                            &sensor_dev_attr_temp1_input.dev_attr);
 340         device_create_file(&new_client->dev,
 341                            &sensor_dev_attr_temp3_input.dev_attr);
 342
 343         device_create_file(&new_client->dev,
 344                            &sensor_dev_attr_temp1_max.dev_attr);
 345         device_create_file(&new_client->dev,
 346                            &sensor_dev_attr_temp3_max.dev_attr);
 347
 348         device_create_file(&new_client->dev,
 349                            &sensor_dev_attr_temp1_crit.dev_attr);
 350         device_create_file(&new_client->dev,
 351                            &sensor_dev_attr_temp3_crit.dev_attr);
 352
 353         device_create_file(&new_client->dev, &dev_attr_alarms);
 354
 355         if (kind == lm83) {
 356                 device_create_file(&new_client->dev,
 357                                    &sensor_dev_attr_temp2_input.dev_attr);
 358                 device_create_file(&new_client->dev,
 359                                    &sensor_dev_attr_temp4_input.dev_attr);
 360
 361                 device_create_file(&new_client->dev,
 362                                    &sensor_dev_attr_temp2_max.dev_attr);
 363                 device_create_file(&new_client->dev,
 364                                    &sensor_dev_attr_temp4_max.dev_attr);
 365
 366                 device_create_file(&new_client->dev,
 367                                    &sensor_dev_attr_temp2_crit.dev_attr);
 368                 device_create_file(&new_client->dev,
 369                                    &sensor_dev_attr_temp4_crit.dev_attr);
 370         }
 371
 372         return 0;
 373
 374 exit_detach:
 375         i2c_detach_client(new_client);
 376 exit_free:
 377         kfree(data);
 378 exit:
 379         return err;
 380 }
 381
 382 static int lm83_detach_client(struct i2c_client *client)
 383 {
 384         struct lm83_data *data = i2c_get_clientdata(client);
 385         int err;
 386
 387         hwmon_device_unregister(data->class_dev);
 388
 389         if ((err = i2c_detach_client(client)))
 390                 return err;
 391
 392         kfree(data);
 393         return 0;
 394 }
 395
 396 static struct lm83_data *lm83_update_device(struct device *dev)
 397 {
 398         struct i2c_client *client = to_i2c_client(dev);
 399         struct lm83_data *data = i2c_get_clientdata(client);
 400
 401         mutex_lock(&data->update_lock);
 402
 403         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 404                 int nr;
 405
 406                 dev_dbg(&client->dev, "Updating lm83 data.\n");
 407                 for (nr = 0; nr < 9; nr++) {
 408                         data->temp[nr] =
 409                             i2c_smbus_read_byte_data(client,
 410                             LM83_REG_R_TEMP[nr]);
 411                 }
 412                 data->alarms =
 413                     i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 414                     + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 415                     << 8);
 416
 417                 data->last_updated = jiffies;
 418                 data->valid = 1;
 419         }
 420
 421         mutex_unlock(&data->update_lock);
 422
 423         return data;
 424 }
 425
 426 static int __init sensors_lm83_init(void)
 427 {
 428         return i2c_add_driver(&lm83_driver);
 429 }
 430
 431 static void __exit sensors_lm83_exit(void)
 432 {
 433         i2c_del_driver(&lm83_driver);
 434 }
 435
 436 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 437 MODULE_DESCRIPTION("LM83 driver");
 438 MODULE_LICENSE("GPL");
 439
 440 module_init(sensors_lm83_init);
 441 module_exit(sensors_lm83_exit);