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  * This program is free software; you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or
  18  * (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  * GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program; if not, write to the Free Software
  27  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  28  */
  29
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/slab.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/i2c.h>
  35 #include <linux/hwmon-sysfs.h>
  36 #include <linux/hwmon.h>
  37 #include <linux/err.h>
  38 #include <linux/mutex.h>
  39
  40 /*
  41  * Addresses to scan
  42  * Address is selected using 2 three-level pins, resulting in 9 possible
  43  * addresses.
  44  */
  45
  46 static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
  47                                         0x29, 0x2a, 0x2b,
  48                                         0x4c, 0x4d, 0x4e,
  49                                         I2C_CLIENT_END };
  50
  51 /*
  52  * Insmod parameters
  53  */
  54
  55 I2C_CLIENT_INSMOD_1(lm83);
  56
  57 /*
  58  * The LM83 registers
  59  * Manufacturer ID is 0x01 for National Semiconductor.
  60  */
  61
  62 #define LM83_REG_R_MAN_ID               0xFE
  63 #define LM83_REG_R_CHIP_ID              0xFF
  64 #define LM83_REG_R_CONFIG               0x03
  65 #define LM83_REG_W_CONFIG               0x09
  66 #define LM83_REG_R_STATUS1              0x02
  67 #define LM83_REG_R_STATUS2              0x35
  68 #define LM83_REG_R_LOCAL_TEMP           0x00
  69 #define LM83_REG_R_LOCAL_HIGH           0x05
  70 #define LM83_REG_W_LOCAL_HIGH           0x0B
  71 #define LM83_REG_R_REMOTE1_TEMP         0x30
  72 #define LM83_REG_R_REMOTE1_HIGH         0x38
  73 #define LM83_REG_W_REMOTE1_HIGH         0x50
  74 #define LM83_REG_R_REMOTE2_TEMP         0x01
  75 #define LM83_REG_R_REMOTE2_HIGH         0x07
  76 #define LM83_REG_W_REMOTE2_HIGH         0x0D
  77 #define LM83_REG_R_REMOTE3_TEMP         0x31
  78 #define LM83_REG_R_REMOTE3_HIGH         0x3A
  79 #define LM83_REG_W_REMOTE3_HIGH         0x52
  80 #define LM83_REG_R_TCRIT                0x42
  81 #define LM83_REG_W_TCRIT                0x5A
  82
  83 /*
  84  * Conversions and various macros
  85  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
  86  */
  87
  88 #define TEMP_FROM_REG(val)      ((val) * 1000)
  89 #define TEMP_TO_REG(val)        ((val) <= -128000 ? -128 : \
  90                                  (val) >= 127000 ? 127 : \
  91                                  (val) < 0 ? ((val) - 500) / 1000 : \
  92                                  ((val) + 500) / 1000)
  93
  94 static const u8 LM83_REG_R_TEMP[] = {
  95         LM83_REG_R_LOCAL_TEMP,
  96         LM83_REG_R_REMOTE1_TEMP,
  97         LM83_REG_R_REMOTE2_TEMP,
  98         LM83_REG_R_REMOTE3_TEMP,
  99         LM83_REG_R_LOCAL_HIGH,
 100         LM83_REG_R_REMOTE1_HIGH,
 101         LM83_REG_R_REMOTE2_HIGH,
 102         LM83_REG_R_REMOTE3_HIGH,
 103         LM83_REG_R_TCRIT,
 104 };
 105
 106 static const u8 LM83_REG_W_HIGH[] = {
 107         LM83_REG_W_LOCAL_HIGH,
 108         LM83_REG_W_REMOTE1_HIGH,
 109         LM83_REG_W_REMOTE2_HIGH,
 110         LM83_REG_W_REMOTE3_HIGH,
 111         LM83_REG_W_TCRIT,
 112 };
 113
 114 /*
 115  * Functions declaration
 116  */
 117
 118 static int lm83_attach_adapter(struct i2c_adapter *adapter);
 119 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
 120 static int lm83_detach_client(struct i2c_client *client);
 121 static struct lm83_data *lm83_update_device(struct device *dev);
 122
 123 /*
 124  * Driver data (common to all clients)
 125  */
 126
 127 static struct i2c_driver lm83_driver = {
 128         .driver = {
 129                 .name   = "lm83",
 130         },
 131         .id             = I2C_DRIVERID_LM83,
 132         .attach_adapter = lm83_attach_adapter,
 133         .detach_client  = lm83_detach_client,
 134 };
 135
 136 /*
 137  * Client data (each client gets its own)
 138  */
 139
 140 struct lm83_data {
 141         struct i2c_client client;
 142         struct class_device *class_dev;
 143         struct mutex update_lock;
 144         char valid; /* zero until following fields are valid */
 145         unsigned long last_updated; /* in jiffies */
 146
 147         /* registers values */
 148         s8 temp[9];     /* 0..3: input 1-4,
 149                            4..7: high limit 1-4,
 150                            8   : critical limit */
 151         u16 alarms; /* bitvector, combined */
 152 };
 153
 154 /*
 155  * Sysfs stuff
 156  */
 157
 158 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 159                          char *buf)
 160 {
 161         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 162         struct lm83_data *data = lm83_update_device(dev);
 163         return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 164 }
 165
 166 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 167                         const char *buf, size_t count)
 168 {
 169         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 170         struct i2c_client *client = to_i2c_client(dev);
 171         struct lm83_data *data = i2c_get_clientdata(client);
 172         long val = simple_strtol(buf, NULL, 10);
 173         int nr = attr->index;
 174
 175         mutex_lock(&data->update_lock);
 176         data->temp[nr] = TEMP_TO_REG(val);
 177         i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
 178                                   data->temp[nr]);
 179         mutex_unlock(&data->update_lock);
 180         return count;
 181 }
 182
 183 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
 184                            char *buf)
 185 {
 186         struct lm83_data *data = lm83_update_device(dev);
 187         return sprintf(buf, "%d\n", data->alarms);
 188 }
 189
 190 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 191 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
 192 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
 193 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
 194 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
 195         set_temp, 4);
 196 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
 197         set_temp, 5);
 198 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
 199         set_temp, 6);
 200 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
 201         set_temp, 7);
 202 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
 203 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
 204 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
 205         set_temp, 8);
 206 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
 207 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 208
 209 /*
 210  * Real code
 211  */
 212
 213 static int lm83_attach_adapter(struct i2c_adapter *adapter)
 214 {
 215         if (!(adapter->class & I2C_CLASS_HWMON))
 216                 return 0;
 217         return i2c_probe(adapter, &addr_data, lm83_detect);
 218 }
 219
 220 /*
 221  * The following function does more than just detection. If detection
 222  * succeeds, it also registers the new chip.
 223  */
 224 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
 225 {
 226         struct i2c_client *new_client;
 227         struct lm83_data *data;
 228         int err = 0;
 229         const char *name = "";
 230
 231         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 232                 goto exit;
 233
 234         if (!(data = kzalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
 235                 err = -ENOMEM;
 236                 goto exit;
 237         }
 238
 239         /* The common I2C client data is placed right after the
 240          * LM83-specific data. */
 241         new_client = &data->client;
 242         i2c_set_clientdata(new_client, data);
 243         new_client->addr = address;
 244         new_client->adapter = adapter;
 245         new_client->driver = &lm83_driver;
 246         new_client->flags = 0;
 247
 248         /* Now we do the detection and identification. A negative kind
 249          * means that the driver was loaded with no force parameter
 250          * (default), so we must both detect and identify the chip
 251          * (actually there is only one possible kind of chip for now, LM83).
 252          * A zero kind means that the driver was loaded with the force
 253          * parameter, the detection step shall be skipped. A positive kind
 254          * means that the driver was loaded with the force parameter and a
 255          * given kind of chip is requested, so both the detection and the
 256          * identification steps are skipped. */
 257
 258         /* Default to an LM83 if forced */
 259         if (kind == 0)
 260                 kind = lm83;
 261
 262         if (kind < 0) { /* detection */
 263                 if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
 264                     & 0xA8) != 0x00) ||
 265                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
 266                     & 0x48) != 0x00) ||
 267                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
 268                     & 0x41) != 0x00)) {
 269                         dev_dbg(&adapter->dev,
 270                             "LM83 detection failed at 0x%02x.\n", address);
 271                         goto exit_free;
 272                 }
 273         }
 274
 275         if (kind <= 0) { /* identification */
 276                 u8 man_id, chip_id;
 277
 278                 man_id = i2c_smbus_read_byte_data(new_client,
 279                     LM83_REG_R_MAN_ID);
 280                 chip_id = i2c_smbus_read_byte_data(new_client,
 281                     LM83_REG_R_CHIP_ID);
 282
 283                 if (man_id == 0x01) { /* National Semiconductor */
 284                         if (chip_id == 0x03) {
 285                                 kind = lm83;
 286                         }
 287                 }
 288
 289                 if (kind <= 0) { /* identification failed */
 290                         dev_info(&adapter->dev,
 291                             "Unsupported chip (man_id=0x%02X, "
 292                             "chip_id=0x%02X).\n", man_id, chip_id);
 293                         goto exit_free;
 294                 }
 295         }
 296
 297         if (kind == lm83) {
 298                 name = "lm83";
 299         }
 300
 301         /* We can fill in the remaining client fields */
 302         strlcpy(new_client->name, name, I2C_NAME_SIZE);
 303         data->valid = 0;
 304         mutex_init(&data->update_lock);
 305
 306         /* Tell the I2C layer a new client has arrived */
 307         if ((err = i2c_attach_client(new_client)))
 308                 goto exit_free;
 309
 310         /*
 311          * Initialize the LM83 chip
 312          * (Nothing to do for this one.)
 313          */
 314
 315         /* Register sysfs hooks */
 316         data->class_dev = hwmon_device_register(&new_client->dev);
 317         if (IS_ERR(data->class_dev)) {
 318                 err = PTR_ERR(data->class_dev);
 319                 goto exit_detach;
 320         }
 321
 322         device_create_file(&new_client->dev,
 323                            &sensor_dev_attr_temp1_input.dev_attr);
 324         device_create_file(&new_client->dev,
 325                            &sensor_dev_attr_temp2_input.dev_attr);
 326         device_create_file(&new_client->dev,
 327                            &sensor_dev_attr_temp3_input.dev_attr);
 328         device_create_file(&new_client->dev,
 329                            &sensor_dev_attr_temp4_input.dev_attr);
 330         device_create_file(&new_client->dev,
 331                            &sensor_dev_attr_temp1_max.dev_attr);
 332         device_create_file(&new_client->dev,
 333                            &sensor_dev_attr_temp2_max.dev_attr);
 334         device_create_file(&new_client->dev,
 335                            &sensor_dev_attr_temp3_max.dev_attr);
 336         device_create_file(&new_client->dev,
 337                            &sensor_dev_attr_temp4_max.dev_attr);
 338         device_create_file(&new_client->dev,
 339                            &sensor_dev_attr_temp1_crit.dev_attr);
 340         device_create_file(&new_client->dev,
 341                            &sensor_dev_attr_temp2_crit.dev_attr);
 342         device_create_file(&new_client->dev,
 343                            &sensor_dev_attr_temp3_crit.dev_attr);
 344         device_create_file(&new_client->dev,
 345                            &sensor_dev_attr_temp4_crit.dev_attr);
 346         device_create_file(&new_client->dev, &dev_attr_alarms);
 347
 348         return 0;
 349
 350 exit_detach:
 351         i2c_detach_client(new_client);
 352 exit_free:
 353         kfree(data);
 354 exit:
 355         return err;
 356 }
 357
 358 static int lm83_detach_client(struct i2c_client *client)
 359 {
 360         struct lm83_data *data = i2c_get_clientdata(client);
 361         int err;
 362
 363         hwmon_device_unregister(data->class_dev);
 364
 365         if ((err = i2c_detach_client(client)))
 366                 return err;
 367
 368         kfree(data);
 369         return 0;
 370 }
 371
 372 static struct lm83_data *lm83_update_device(struct device *dev)
 373 {
 374         struct i2c_client *client = to_i2c_client(dev);
 375         struct lm83_data *data = i2c_get_clientdata(client);
 376
 377         mutex_lock(&data->update_lock);
 378
 379         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 380                 int nr;
 381
 382                 dev_dbg(&client->dev, "Updating lm83 data.\n");
 383                 for (nr = 0; nr < 9; nr++) {
 384                         data->temp[nr] =
 385                             i2c_smbus_read_byte_data(client,
 386                             LM83_REG_R_TEMP[nr]);
 387                 }
 388                 data->alarms =
 389                     i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 390                     + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 391                     << 8);
 392
 393                 data->last_updated = jiffies;
 394                 data->valid = 1;
 395         }
 396
 397         mutex_unlock(&data->update_lock);
 398
 399         return data;
 400 }
 401
 402 static int __init sensors_lm83_init(void)
 403 {
 404         return i2c_add_driver(&lm83_driver);
 405 }
 406
 407 static void __exit sensors_lm83_exit(void)
 408 {
 409         i2c_del_driver(&lm83_driver);
 410 }
 411
 412 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 413 MODULE_DESCRIPTION("LM83 driver");
 414 MODULE_LICENSE("GPL");
 415
 416 module_init(sensors_lm83_init);
 417 module_exit(sensors_lm83_exit);