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/i2c-sensor.h>
  36 #include <linux/hwmon-sysfs.h>
  37 #include <linux/hwmon.h>
  38 #include <linux/err.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 static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
  51
  52 /*
  53  * Insmod parameters
  54  */
  55
  56 SENSORS_INSMOD_1(lm83);
  57
  58 /*
  59  * The LM83 registers
  60  * Manufacturer ID is 0x01 for National Semiconductor.
  61  */
  62
  63 #define LM83_REG_R_MAN_ID               0xFE
  64 #define LM83_REG_R_CHIP_ID              0xFF
  65 #define LM83_REG_R_CONFIG               0x03
  66 #define LM83_REG_W_CONFIG               0x09
  67 #define LM83_REG_R_STATUS1              0x02
  68 #define LM83_REG_R_STATUS2              0x35
  69 #define LM83_REG_R_LOCAL_TEMP           0x00
  70 #define LM83_REG_R_LOCAL_HIGH           0x05
  71 #define LM83_REG_W_LOCAL_HIGH           0x0B
  72 #define LM83_REG_R_REMOTE1_TEMP         0x30
  73 #define LM83_REG_R_REMOTE1_HIGH         0x38
  74 #define LM83_REG_W_REMOTE1_HIGH         0x50
  75 #define LM83_REG_R_REMOTE2_TEMP         0x01
  76 #define LM83_REG_R_REMOTE2_HIGH         0x07
  77 #define LM83_REG_W_REMOTE2_HIGH         0x0D
  78 #define LM83_REG_R_REMOTE3_TEMP         0x31
  79 #define LM83_REG_R_REMOTE3_HIGH         0x3A
  80 #define LM83_REG_W_REMOTE3_HIGH         0x52
  81 #define LM83_REG_R_TCRIT                0x42
  82 #define LM83_REG_W_TCRIT                0x5A
  83
  84 /*
  85  * Conversions and various macros
  86  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
  87  */
  88
  89 #define TEMP_FROM_REG(val)      ((val) * 1000)
  90 #define TEMP_TO_REG(val)        ((val) <= -128000 ? -128 : \
  91                                  (val) >= 127000 ? 127 : \
  92                                  (val) < 0 ? ((val) - 500) / 1000 : \
  93                                  ((val) + 500) / 1000)
  94
  95 static const u8 LM83_REG_R_TEMP[] = {
  96         LM83_REG_R_LOCAL_TEMP,
  97         LM83_REG_R_REMOTE1_TEMP,
  98         LM83_REG_R_REMOTE2_TEMP,
  99         LM83_REG_R_REMOTE3_TEMP,
 100         LM83_REG_R_LOCAL_HIGH,
 101         LM83_REG_R_REMOTE1_HIGH,
 102         LM83_REG_R_REMOTE2_HIGH,
 103         LM83_REG_R_REMOTE3_HIGH,
 104         LM83_REG_R_TCRIT,
 105 };
 106
 107 static const u8 LM83_REG_W_HIGH[] = {
 108         LM83_REG_W_LOCAL_HIGH,
 109         LM83_REG_W_REMOTE1_HIGH,
 110         LM83_REG_W_REMOTE2_HIGH,
 111         LM83_REG_W_REMOTE3_HIGH,
 112         LM83_REG_W_TCRIT,
 113 };
 114
 115 /*
 116  * Functions declaration
 117  */
 118
 119 static int lm83_attach_adapter(struct i2c_adapter *adapter);
 120 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
 121 static int lm83_detach_client(struct i2c_client *client);
 122 static struct lm83_data *lm83_update_device(struct device *dev);
 123
 124 /*
 125  * Driver data (common to all clients)
 126  */
 127
 128 static struct i2c_driver lm83_driver = {
 129         .owner          = THIS_MODULE,
 130         .name           = "lm83",
 131         .id             = I2C_DRIVERID_LM83,
 132         .flags          = I2C_DF_NOTIFY,
 133         .attach_adapter = lm83_attach_adapter,
 134         .detach_client  = lm83_detach_client,
 135 };
 136
 137 /*
 138  * Client data (each client gets its own)
 139  */
 140
 141 struct lm83_data {
 142         struct i2c_client client;
 143         struct class_device *class_dev;
 144         struct semaphore update_lock;
 145         char valid; /* zero until following fields are valid */
 146         unsigned long last_updated; /* in jiffies */
 147
 148         /* registers values */
 149         s8 temp[9];     /* 0..3: input 1-4,
 150                            4..7: high limit 1-4,
 151                            8   : critical limit */
 152         u16 alarms; /* bitvector, combined */
 153 };
 154
 155 /*
 156  * Sysfs stuff
 157  */
 158
 159 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 160                          char *buf)
 161 {
 162         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 163         struct lm83_data *data = lm83_update_device(dev);
 164         return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 165 }
 166
 167 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 168                         const char *buf, size_t count)
 169 {
 170         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 171         struct i2c_client *client = to_i2c_client(dev);
 172         struct lm83_data *data = i2c_get_clientdata(client);
 173         long val = simple_strtol(buf, NULL, 10);
 174         int nr = attr->index;
 175
 176         down(&data->update_lock);
 177         data->temp[nr] = TEMP_TO_REG(val);
 178         i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
 179                                   data->temp[nr]);
 180         up(&data->update_lock);
 181         return count;
 182 }
 183
 184 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
 185                            char *buf)
 186 {
 187         struct lm83_data *data = lm83_update_device(dev);
 188         return sprintf(buf, "%d\n", data->alarms);
 189 }
 190
 191 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 192 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
 193 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
 194 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
 195 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
 196         set_temp, 4);
 197 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
 198         set_temp, 5);
 199 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
 200         set_temp, 6);
 201 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
 202         set_temp, 7);
 203 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
 204 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
 205 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
 206         set_temp, 8);
 207 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
 208 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 209
 210 /*
 211  * Real code
 212  */
 213
 214 static int lm83_attach_adapter(struct i2c_adapter *adapter)
 215 {
 216         if (!(adapter->class & I2C_CLASS_HWMON))
 217                 return 0;
 218         return i2c_detect(adapter, &addr_data, lm83_detect);
 219 }
 220
 221 /*
 222  * The following function does more than just detection. If detection
 223  * succeeds, it also registers the new chip.
 224  */
 225 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
 226 {
 227         struct i2c_client *new_client;
 228         struct lm83_data *data;
 229         int err = 0;
 230         const char *name = "";
 231
 232         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 233                 goto exit;
 234
 235         if (!(data = kmalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
 236                 err = -ENOMEM;
 237                 goto exit;
 238         }
 239         memset(data, 0, sizeof(struct lm83_data));
 240
 241         /* The common I2C client data is placed right after the
 242          * LM83-specific data. */
 243         new_client = &data->client;
 244         i2c_set_clientdata(new_client, data);
 245         new_client->addr = address;
 246         new_client->adapter = adapter;
 247         new_client->driver = &lm83_driver;
 248         new_client->flags = 0;
 249
 250         /* Now we do the detection and identification. A negative kind
 251          * means that the driver was loaded with no force parameter
 252          * (default), so we must both detect and identify the chip
 253          * (actually there is only one possible kind of chip for now, LM83).
 254          * A zero kind means that the driver was loaded with the force
 255          * parameter, the detection step shall be skipped. A positive kind
 256          * means that the driver was loaded with the force parameter and a
 257          * given kind of chip is requested, so both the detection and the
 258          * identification steps are skipped. */
 259
 260         /* Default to an LM83 if forced */
 261         if (kind == 0)
 262                 kind = lm83;
 263
 264         if (kind < 0) { /* detection */
 265                 if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
 266                     & 0xA8) != 0x00) ||
 267                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
 268                     & 0x48) != 0x00) ||
 269                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
 270                     & 0x41) != 0x00)) {
 271                         dev_dbg(&adapter->dev,
 272                             "LM83 detection failed at 0x%02x.\n", address);
 273                         goto exit_free;
 274                 }
 275         }
 276
 277         if (kind <= 0) { /* identification */
 278                 u8 man_id, chip_id;
 279
 280                 man_id = i2c_smbus_read_byte_data(new_client,
 281                     LM83_REG_R_MAN_ID);
 282                 chip_id = i2c_smbus_read_byte_data(new_client,
 283                     LM83_REG_R_CHIP_ID);
 284
 285                 if (man_id == 0x01) { /* National Semiconductor */
 286                         if (chip_id == 0x03) {
 287                                 kind = lm83;
 288                         }
 289                 }
 290
 291                 if (kind <= 0) { /* identification failed */
 292                         dev_info(&adapter->dev,
 293                             "Unsupported chip (man_id=0x%02X, "
 294                             "chip_id=0x%02X).\n", man_id, chip_id);
 295                         goto exit_free;
 296                 }
 297         }
 298
 299         if (kind == lm83) {
 300                 name = "lm83";
 301         }
 302
 303         /* We can fill in the remaining client fields */
 304         strlcpy(new_client->name, name, I2C_NAME_SIZE);
 305         data->valid = 0;
 306         init_MUTEX(&data->update_lock);
 307
 308         /* Tell the I2C layer a new client has arrived */
 309         if ((err = i2c_attach_client(new_client)))
 310                 goto exit_free;
 311
 312         /*
 313          * Initialize the LM83 chip
 314          * (Nothing to do for this one.)
 315          */
 316
 317         /* Register sysfs hooks */
 318         data->class_dev = hwmon_device_register(&new_client->dev);
 319         if (IS_ERR(data->class_dev)) {
 320                 err = PTR_ERR(data->class_dev);
 321                 goto exit_detach;
 322         }
 323
 324         device_create_file(&new_client->dev,
 325                            &sensor_dev_attr_temp1_input.dev_attr);
 326         device_create_file(&new_client->dev,
 327                            &sensor_dev_attr_temp2_input.dev_attr);
 328         device_create_file(&new_client->dev,
 329                            &sensor_dev_attr_temp3_input.dev_attr);
 330         device_create_file(&new_client->dev,
 331                            &sensor_dev_attr_temp4_input.dev_attr);
 332         device_create_file(&new_client->dev,
 333                            &sensor_dev_attr_temp1_max.dev_attr);
 334         device_create_file(&new_client->dev,
 335                            &sensor_dev_attr_temp2_max.dev_attr);
 336         device_create_file(&new_client->dev,
 337                            &sensor_dev_attr_temp3_max.dev_attr);
 338         device_create_file(&new_client->dev,
 339                            &sensor_dev_attr_temp4_max.dev_attr);
 340         device_create_file(&new_client->dev,
 341                            &sensor_dev_attr_temp1_crit.dev_attr);
 342         device_create_file(&new_client->dev,
 343                            &sensor_dev_attr_temp2_crit.dev_attr);
 344         device_create_file(&new_client->dev,
 345                            &sensor_dev_attr_temp3_crit.dev_attr);
 346         device_create_file(&new_client->dev,
 347                            &sensor_dev_attr_temp4_crit.dev_attr);
 348         device_create_file(&new_client->dev, &dev_attr_alarms);
 349
 350         return 0;
 351
 352 exit_detach:
 353         i2c_detach_client(new_client);
 354 exit_free:
 355         kfree(data);
 356 exit:
 357         return err;
 358 }
 359
 360 static int lm83_detach_client(struct i2c_client *client)
 361 {
 362         struct lm83_data *data = i2c_get_clientdata(client);
 363         int err;
 364
 365         hwmon_device_unregister(data->class_dev);
 366
 367         if ((err = i2c_detach_client(client))) {
 368                 dev_err(&client->dev,
 369                     "Client deregistration failed, client not detached.\n");
 370                 return err;
 371         }
 372
 373         kfree(data);
 374         return 0;
 375 }
 376
 377 static struct lm83_data *lm83_update_device(struct device *dev)
 378 {
 379         struct i2c_client *client = to_i2c_client(dev);
 380         struct lm83_data *data = i2c_get_clientdata(client);
 381
 382         down(&data->update_lock);
 383
 384         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 385                 int nr;
 386
 387                 dev_dbg(&client->dev, "Updating lm83 data.\n");
 388                 for (nr = 0; nr < 9; nr++) {
 389                         data->temp[nr] =
 390                             i2c_smbus_read_byte_data(client,
 391                             LM83_REG_R_TEMP[nr]);
 392                 }
 393                 data->alarms =
 394                     i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 395                     + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 396                     << 8);
 397
 398                 data->last_updated = jiffies;
 399                 data->valid = 1;
 400         }
 401
 402         up(&data->update_lock);
 403
 404         return data;
 405 }
 406
 407 static int __init sensors_lm83_init(void)
 408 {
 409         return i2c_add_driver(&lm83_driver);
 410 }
 411
 412 static void __exit sensors_lm83_exit(void)
 413 {
 414         i2c_del_driver(&lm83_driver);
 415 }
 416
 417 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 418 MODULE_DESCRIPTION("LM83 driver");
 419 MODULE_LICENSE("GPL");
 420
 421 module_init(sensors_lm83_init);
 422 module_exit(sensors_lm83_exit);