drivers/i2c/chips/lm83.c

   1 /*
   2  * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
   3  *          monitoring
   4  * Copyright (C) 2003  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/config.h>
  31 #include <linux/module.h>
  32 #include <linux/init.h>
  33 #include <linux/slab.h>
  34 #include <linux/jiffies.h>
  35 #include <linux/i2c.h>
  36 #include <linux/i2c-sensor.h>
  37
  38 /*
  39  * Addresses to scan
  40  * Address is selected using 2 three-level pins, resulting in 9 possible
  41  * addresses.
  42  */
  43
  44 static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
  45                                         0x29, 0x2a, 0x2b,
  46                                         0x4c, 0x4d, 0x4e,
  47                                         I2C_CLIENT_END };
  48 static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
  49
  50 /*
  51  * Insmod parameters
  52  */
  53
  54 SENSORS_INSMOD_1(lm83);
  55
  56 /*
  57  * The LM83 registers
  58  * Manufacturer ID is 0x01 for National Semiconductor.
  59  */
  60
  61 #define LM83_REG_R_MAN_ID               0xFE
  62 #define LM83_REG_R_CHIP_ID              0xFF
  63 #define LM83_REG_R_CONFIG               0x03
  64 #define LM83_REG_W_CONFIG               0x09
  65 #define LM83_REG_R_STATUS1              0x02
  66 #define LM83_REG_R_STATUS2              0x35
  67 #define LM83_REG_R_LOCAL_TEMP           0x00
  68 #define LM83_REG_R_LOCAL_HIGH           0x05
  69 #define LM83_REG_W_LOCAL_HIGH           0x0B
  70 #define LM83_REG_R_REMOTE1_TEMP         0x30
  71 #define LM83_REG_R_REMOTE1_HIGH         0x38
  72 #define LM83_REG_W_REMOTE1_HIGH         0x50
  73 #define LM83_REG_R_REMOTE2_TEMP         0x01
  74 #define LM83_REG_R_REMOTE2_HIGH         0x07
  75 #define LM83_REG_W_REMOTE2_HIGH         0x0D
  76 #define LM83_REG_R_REMOTE3_TEMP         0x31
  77 #define LM83_REG_R_REMOTE3_HIGH         0x3A
  78 #define LM83_REG_W_REMOTE3_HIGH         0x52
  79 #define LM83_REG_R_TCRIT                0x42
  80 #define LM83_REG_W_TCRIT                0x5A
  81
  82 /*
  83  * Conversions and various macros
  84  * The LM83 uses signed 8-bit values with LSB = 1 degree Celcius.
  85  */
  86
  87 #define TEMP_FROM_REG(val)      ((val) * 1000)
  88 #define TEMP_TO_REG(val)        ((val) <= -128000 ? -128 : \
  89                                  (val) >= 127000 ? 127 : \
  90                                  (val) < 0 ? ((val) - 500) / 1000 : \
  91                                  ((val) + 500) / 1000)
  92
  93 static const u8 LM83_REG_R_TEMP[] = {
  94         LM83_REG_R_LOCAL_TEMP,
  95         LM83_REG_R_REMOTE1_TEMP,
  96         LM83_REG_R_REMOTE2_TEMP,
  97         LM83_REG_R_REMOTE3_TEMP
  98 };
  99
 100 static const u8 LM83_REG_R_HIGH[] = {
 101         LM83_REG_R_LOCAL_HIGH,
 102         LM83_REG_R_REMOTE1_HIGH,
 103         LM83_REG_R_REMOTE2_HIGH,
 104         LM83_REG_R_REMOTE3_HIGH
 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 };
 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         .owner          = THIS_MODULE,
 129         .name           = "lm83",
 130         .id             = I2C_DRIVERID_LM83,
 131         .flags          = I2C_DF_NOTIFY,
 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 semaphore update_lock;
 143         char valid; /* zero until following fields are valid */
 144         unsigned long last_updated; /* in jiffies */
 145
 146         /* registers values */
 147         s8 temp_input[4];
 148         s8 temp_high[4];
 149         s8 temp_crit;
 150         u16 alarms; /* bitvector, combined */
 151 };
 152
 153 /*
 154  * Sysfs stuff
 155  */
 156
 157 #define show_temp(suffix, value) \
 158 static ssize_t show_temp_##suffix(struct device *dev, char *buf) \
 159 { \
 160         struct lm83_data *data = lm83_update_device(dev); \
 161         return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
 162 }
 163 show_temp(input1, temp_input[0]);
 164 show_temp(input2, temp_input[1]);
 165 show_temp(input3, temp_input[2]);
 166 show_temp(input4, temp_input[3]);
 167 show_temp(high1, temp_high[0]);
 168 show_temp(high2, temp_high[1]);
 169 show_temp(high3, temp_high[2]);
 170 show_temp(high4, temp_high[3]);
 171 show_temp(crit, temp_crit);
 172
 173 #define set_temp(suffix, value, reg) \
 174 static ssize_t set_temp_##suffix(struct device *dev, const char *buf, \
 175         size_t count) \
 176 { \
 177         struct i2c_client *client = to_i2c_client(dev); \
 178         struct lm83_data *data = i2c_get_clientdata(client); \
 179         long val = simple_strtol(buf, NULL, 10); \
 180  \
 181         down(&data->update_lock); \
 182         data->value = TEMP_TO_REG(val); \
 183         i2c_smbus_write_byte_data(client, reg, data->value); \
 184         up(&data->update_lock); \
 185         return count; \
 186 }
 187 set_temp(high1, temp_high[0], LM83_REG_W_LOCAL_HIGH);
 188 set_temp(high2, temp_high[1], LM83_REG_W_REMOTE1_HIGH);
 189 set_temp(high3, temp_high[2], LM83_REG_W_REMOTE2_HIGH);
 190 set_temp(high4, temp_high[3], LM83_REG_W_REMOTE3_HIGH);
 191 set_temp(crit, temp_crit, LM83_REG_W_TCRIT);
 192
 193 static ssize_t show_alarms(struct device *dev, char *buf)
 194 {
 195         struct lm83_data *data = lm83_update_device(dev);
 196         return sprintf(buf, "%d\n", data->alarms);
 197 }
 198
 199 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
 200 static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL);
 201 static DEVICE_ATTR(temp3_input, S_IRUGO, show_temp_input3, NULL);
 202 static DEVICE_ATTR(temp4_input, S_IRUGO, show_temp_input4, NULL);
 203 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_high1,
 204     set_temp_high1);
 205 static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_high2,
 206     set_temp_high2);
 207 static DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp_high3,
 208     set_temp_high3);
 209 static DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp_high4,
 210     set_temp_high4);
 211 static DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp_crit, NULL);
 212 static DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp_crit, NULL);
 213 static DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp_crit,
 214     set_temp_crit);
 215 static DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp_crit, NULL);
 216 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 217
 218 /*
 219  * Real code
 220  */
 221
 222 static int lm83_attach_adapter(struct i2c_adapter *adapter)
 223 {
 224         if (!(adapter->class & I2C_CLASS_HWMON))
 225                 return 0;
 226         return i2c_detect(adapter, &addr_data, lm83_detect);
 227 }
 228
 229 /*
 230  * The following function does more than just detection. If detection
 231  * succeeds, it also registers the new chip.
 232  */
 233 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
 234 {
 235         struct i2c_client *new_client;
 236         struct lm83_data *data;
 237         int err = 0;
 238         const char *name = "";
 239
 240         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 241                 goto exit;
 242
 243         if (!(data = kmalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
 244                 err = -ENOMEM;
 245                 goto exit;
 246         }
 247         memset(data, 0, sizeof(struct lm83_data));
 248
 249         /* The common I2C client data is placed right after the
 250          * LM83-specific data. */
 251         new_client = &data->client;
 252         i2c_set_clientdata(new_client, data);
 253         new_client->addr = address;
 254         new_client->adapter = adapter;
 255         new_client->driver = &lm83_driver;
 256         new_client->flags = 0;
 257
 258         /* Now we do the detection and identification. A negative kind
 259          * means that the driver was loaded with no force parameter
 260          * (default), so we must both detect and identify the chip
 261          * (actually there is only one possible kind of chip for now, LM83).
 262          * A zero kind means that the driver was loaded with the force
 263          * parameter, the detection step shall be skipped. A positive kind
 264          * means that the driver was loaded with the force parameter and a
 265          * given kind of chip is requested, so both the detection and the
 266          * identification steps are skipped. */
 267
 268         /* Default to an LM83 if forced */
 269         if (kind == 0)
 270                 kind = lm83;
 271
 272         if (kind < 0) { /* detection */
 273                 if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
 274                     & 0xA8) != 0x00) ||
 275                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
 276                     & 0x48) != 0x00) ||
 277                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
 278                     & 0x41) != 0x00)) {
 279                         dev_dbg(&adapter->dev,
 280                             "LM83 detection failed at 0x%02x.\n", address);
 281                         goto exit_free;
 282                 }
 283         }
 284
 285         if (kind <= 0) { /* identification */
 286                 u8 man_id, chip_id;
 287
 288                 man_id = i2c_smbus_read_byte_data(new_client,
 289                     LM83_REG_R_MAN_ID);
 290                 chip_id = i2c_smbus_read_byte_data(new_client,
 291                     LM83_REG_R_CHIP_ID);
 292
 293                 if (man_id == 0x01) { /* National Semiconductor */
 294                         if (chip_id == 0x03) {
 295                                 kind = lm83;
 296                         }
 297                 }
 298
 299                 if (kind <= 0) { /* identification failed */
 300                         dev_info(&adapter->dev,
 301                             "Unsupported chip (man_id=0x%02X, "
 302                             "chip_id=0x%02X).\n", man_id, chip_id);
 303                         goto exit_free;
 304                 }
 305         }
 306
 307         if (kind == lm83) {
 308                 name = "lm83";
 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         init_MUTEX(&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         device_create_file(&new_client->dev, &dev_attr_temp1_input);
 327         device_create_file(&new_client->dev, &dev_attr_temp2_input);
 328         device_create_file(&new_client->dev, &dev_attr_temp3_input);
 329         device_create_file(&new_client->dev, &dev_attr_temp4_input);
 330         device_create_file(&new_client->dev, &dev_attr_temp1_max);
 331         device_create_file(&new_client->dev, &dev_attr_temp2_max);
 332         device_create_file(&new_client->dev, &dev_attr_temp3_max);
 333         device_create_file(&new_client->dev, &dev_attr_temp4_max);
 334         device_create_file(&new_client->dev, &dev_attr_temp1_crit);
 335         device_create_file(&new_client->dev, &dev_attr_temp2_crit);
 336         device_create_file(&new_client->dev, &dev_attr_temp3_crit);
 337         device_create_file(&new_client->dev, &dev_attr_temp4_crit);
 338         device_create_file(&new_client->dev, &dev_attr_alarms);
 339
 340         return 0;
 341
 342 exit_free:
 343         kfree(data);
 344 exit:
 345         return err;
 346 }
 347
 348 static int lm83_detach_client(struct i2c_client *client)
 349 {
 350         int err;
 351
 352         if ((err = i2c_detach_client(client))) {
 353                 dev_err(&client->dev,
 354                     "Client deregistration failed, client not detached.\n");
 355                 return err;
 356         }
 357
 358         kfree(i2c_get_clientdata(client));
 359         return 0;
 360 }
 361
 362 static struct lm83_data *lm83_update_device(struct device *dev)
 363 {
 364         struct i2c_client *client = to_i2c_client(dev);
 365         struct lm83_data *data = i2c_get_clientdata(client);
 366
 367         down(&data->update_lock);
 368
 369         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 370                 int nr;
 371
 372                 dev_dbg(&client->dev, "Updating lm83 data.\n");
 373                 for (nr = 0; nr < 4 ; nr++) {
 374                         data->temp_input[nr] =
 375                             i2c_smbus_read_byte_data(client,
 376                             LM83_REG_R_TEMP[nr]);
 377                         data->temp_high[nr] =
 378                             i2c_smbus_read_byte_data(client,
 379                             LM83_REG_R_HIGH[nr]);
 380                 }
 381                 data->temp_crit =
 382                     i2c_smbus_read_byte_data(client, LM83_REG_R_TCRIT);
 383                 data->alarms =
 384                     i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 385                     + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 386                     << 8);
 387
 388                 data->last_updated = jiffies;
 389                 data->valid = 1;
 390         }
 391
 392         up(&data->update_lock);
 393
 394         return data;
 395 }
 396
 397 static int __init sensors_lm83_init(void)
 398 {
 399         return i2c_add_driver(&lm83_driver);
 400 }
 401
 402 static void __exit sensors_lm83_exit(void)
 403 {
 404         i2c_del_driver(&lm83_driver);
 405 }
 406
 407 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 408 MODULE_DESCRIPTION("LM83 driver");
 409 MODULE_LICENSE("GPL");
 410
 411 module_init(sensors_lm83_init);
 412 module_exit(sensors_lm83_exit);