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/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
  37 /*
  38  * Addresses to scan
  39  * Address is selected using 2 three-level pins, resulting in 9 possible
  40  * addresses.
  41  */
  42
  43 static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
  44                                         0x29, 0x2a, 0x2b,
  45                                         0x4c, 0x4d, 0x4e,
  46                                         I2C_CLIENT_END };
  47 static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
  48
  49 /*
  50  * Insmod parameters
  51  */
  52
  53 SENSORS_INSMOD_1(lm83);
  54
  55 /*
  56  * The LM83 registers
  57  * Manufacturer ID is 0x01 for National Semiconductor.
  58  */
  59
  60 #define LM83_REG_R_MAN_ID               0xFE
  61 #define LM83_REG_R_CHIP_ID              0xFF
  62 #define LM83_REG_R_CONFIG               0x03
  63 #define LM83_REG_W_CONFIG               0x09
  64 #define LM83_REG_R_STATUS1              0x02
  65 #define LM83_REG_R_STATUS2              0x35
  66 #define LM83_REG_R_LOCAL_TEMP           0x00
  67 #define LM83_REG_R_LOCAL_HIGH           0x05
  68 #define LM83_REG_W_LOCAL_HIGH           0x0B
  69 #define LM83_REG_R_REMOTE1_TEMP         0x30
  70 #define LM83_REG_R_REMOTE1_HIGH         0x38
  71 #define LM83_REG_W_REMOTE1_HIGH         0x50
  72 #define LM83_REG_R_REMOTE2_TEMP         0x01
  73 #define LM83_REG_R_REMOTE2_HIGH         0x07
  74 #define LM83_REG_W_REMOTE2_HIGH         0x0D
  75 #define LM83_REG_R_REMOTE3_TEMP         0x31
  76 #define LM83_REG_R_REMOTE3_HIGH         0x3A
  77 #define LM83_REG_W_REMOTE3_HIGH         0x52
  78 #define LM83_REG_R_TCRIT                0x42
  79 #define LM83_REG_W_TCRIT                0x5A
  80
  81 /*
  82  * Conversions and various macros
  83  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
  84  */
  85
  86 #define TEMP_FROM_REG(val)      ((val) * 1000)
  87 #define TEMP_TO_REG(val)        ((val) <= -128000 ? -128 : \
  88                                  (val) >= 127000 ? 127 : \
  89                                  (val) < 0 ? ((val) - 500) / 1000 : \
  90                                  ((val) + 500) / 1000)
  91
  92 static const u8 LM83_REG_R_TEMP[] = {
  93         LM83_REG_R_LOCAL_TEMP,
  94         LM83_REG_R_REMOTE1_TEMP,
  95         LM83_REG_R_REMOTE2_TEMP,
  96         LM83_REG_R_REMOTE3_TEMP
  97 };
  98
  99 static const u8 LM83_REG_R_HIGH[] = {
 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 };
 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 };
 112
 113 /*
 114  * Functions declaration
 115  */
 116
 117 static int lm83_attach_adapter(struct i2c_adapter *adapter);
 118 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
 119 static int lm83_detach_client(struct i2c_client *client);
 120 static struct lm83_data *lm83_update_device(struct device *dev);
 121
 122 /*
 123  * Driver data (common to all clients)
 124  */
 125
 126 static struct i2c_driver lm83_driver = {
 127         .owner          = THIS_MODULE,
 128         .name           = "lm83",
 129         .id             = I2C_DRIVERID_LM83,
 130         .flags          = I2C_DF_NOTIFY,
 131         .attach_adapter = lm83_attach_adapter,
 132         .detach_client  = lm83_detach_client,
 133 };
 134
 135 /*
 136  * Client data (each client gets its own)
 137  */
 138
 139 struct lm83_data {
 140         struct i2c_client client;
 141         struct semaphore update_lock;
 142         char valid; /* zero until following fields are valid */
 143         unsigned long last_updated; /* in jiffies */
 144
 145         /* registers values */
 146         s8 temp_input[4];
 147         s8 temp_high[4];
 148         s8 temp_crit;
 149         u16 alarms; /* bitvector, combined */
 150 };
 151
 152 /*
 153  * Sysfs stuff
 154  */
 155
 156 #define show_temp(suffix, value) \
 157 static ssize_t show_temp_##suffix(struct device *dev, struct device_attribute *attr, char *buf) \
 158 { \
 159         struct lm83_data *data = lm83_update_device(dev); \
 160         return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
 161 }
 162 show_temp(input1, temp_input[0]);
 163 show_temp(input2, temp_input[1]);
 164 show_temp(input3, temp_input[2]);
 165 show_temp(input4, temp_input[3]);
 166 show_temp(high1, temp_high[0]);
 167 show_temp(high2, temp_high[1]);
 168 show_temp(high3, temp_high[2]);
 169 show_temp(high4, temp_high[3]);
 170 show_temp(crit, temp_crit);
 171
 172 #define set_temp(suffix, value, reg) \
 173 static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
 174         size_t count) \
 175 { \
 176         struct i2c_client *client = to_i2c_client(dev); \
 177         struct lm83_data *data = i2c_get_clientdata(client); \
 178         long val = simple_strtol(buf, NULL, 10); \
 179  \
 180         down(&data->update_lock); \
 181         data->value = TEMP_TO_REG(val); \
 182         i2c_smbus_write_byte_data(client, reg, data->value); \
 183         up(&data->update_lock); \
 184         return count; \
 185 }
 186 set_temp(high1, temp_high[0], LM83_REG_W_LOCAL_HIGH);
 187 set_temp(high2, temp_high[1], LM83_REG_W_REMOTE1_HIGH);
 188 set_temp(high3, temp_high[2], LM83_REG_W_REMOTE2_HIGH);
 189 set_temp(high4, temp_high[3], LM83_REG_W_REMOTE3_HIGH);
 190 set_temp(crit, temp_crit, LM83_REG_W_TCRIT);
 191
 192 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
 193 {
 194         struct lm83_data *data = lm83_update_device(dev);
 195         return sprintf(buf, "%d\n", data->alarms);
 196 }
 197
 198 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
 199 static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL);
 200 static DEVICE_ATTR(temp3_input, S_IRUGO, show_temp_input3, NULL);
 201 static DEVICE_ATTR(temp4_input, S_IRUGO, show_temp_input4, NULL);
 202 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_high1,
 203     set_temp_high1);
 204 static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_high2,
 205     set_temp_high2);
 206 static DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp_high3,
 207     set_temp_high3);
 208 static DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp_high4,
 209     set_temp_high4);
 210 static DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp_crit, NULL);
 211 static DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp_crit, NULL);
 212 static DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp_crit,
 213     set_temp_crit);
 214 static DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp_crit, NULL);
 215 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 216
 217 /*
 218  * Real code
 219  */
 220
 221 static int lm83_attach_adapter(struct i2c_adapter *adapter)
 222 {
 223         if (!(adapter->class & I2C_CLASS_HWMON))
 224                 return 0;
 225         return i2c_detect(adapter, &addr_data, lm83_detect);
 226 }
 227
 228 /*
 229  * The following function does more than just detection. If detection
 230  * succeeds, it also registers the new chip.
 231  */
 232 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
 233 {
 234         struct i2c_client *new_client;
 235         struct lm83_data *data;
 236         int err = 0;
 237         const char *name = "";
 238
 239         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 240                 goto exit;
 241
 242         if (!(data = kmalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
 243                 err = -ENOMEM;
 244                 goto exit;
 245         }
 246         memset(data, 0, sizeof(struct lm83_data));
 247
 248         /* The common I2C client data is placed right after the
 249          * LM83-specific data. */
 250         new_client = &data->client;
 251         i2c_set_clientdata(new_client, data);
 252         new_client->addr = address;
 253         new_client->adapter = adapter;
 254         new_client->driver = &lm83_driver;
 255         new_client->flags = 0;
 256
 257         /* Now we do the detection and identification. A negative kind
 258          * means that the driver was loaded with no force parameter
 259          * (default), so we must both detect and identify the chip
 260          * (actually there is only one possible kind of chip for now, LM83).
 261          * A zero kind means that the driver was loaded with the force
 262          * parameter, the detection step shall be skipped. A positive kind
 263          * means that the driver was loaded with the force parameter and a
 264          * given kind of chip is requested, so both the detection and the
 265          * identification steps are skipped. */
 266
 267         /* Default to an LM83 if forced */
 268         if (kind == 0)
 269                 kind = lm83;
 270
 271         if (kind < 0) { /* detection */
 272                 if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
 273                     & 0xA8) != 0x00) ||
 274                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
 275                     & 0x48) != 0x00) ||
 276                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
 277                     & 0x41) != 0x00)) {
 278                         dev_dbg(&adapter->dev,
 279                             "LM83 detection failed at 0x%02x.\n", address);
 280                         goto exit_free;
 281                 }
 282         }
 283
 284         if (kind <= 0) { /* identification */
 285                 u8 man_id, chip_id;
 286
 287                 man_id = i2c_smbus_read_byte_data(new_client,
 288                     LM83_REG_R_MAN_ID);
 289                 chip_id = i2c_smbus_read_byte_data(new_client,
 290                     LM83_REG_R_CHIP_ID);
 291
 292                 if (man_id == 0x01) { /* National Semiconductor */
 293                         if (chip_id == 0x03) {
 294                                 kind = lm83;
 295                         }
 296                 }
 297
 298                 if (kind <= 0) { /* identification failed */
 299                         dev_info(&adapter->dev,
 300                             "Unsupported chip (man_id=0x%02X, "
 301                             "chip_id=0x%02X).\n", man_id, chip_id);
 302                         goto exit_free;
 303                 }
 304         }
 305
 306         if (kind == lm83) {
 307                 name = "lm83";
 308         }
 309
 310         /* We can fill in the remaining client fields */
 311         strlcpy(new_client->name, name, I2C_NAME_SIZE);
 312         data->valid = 0;
 313         init_MUTEX(&data->update_lock);
 314
 315         /* Tell the I2C layer a new client has arrived */
 316         if ((err = i2c_attach_client(new_client)))
 317                 goto exit_free;
 318
 319         /*
 320          * Initialize the LM83 chip
 321          * (Nothing to do for this one.)
 322          */
 323
 324         /* Register sysfs hooks */
 325         device_create_file(&new_client->dev, &dev_attr_temp1_input);
 326         device_create_file(&new_client->dev, &dev_attr_temp2_input);
 327         device_create_file(&new_client->dev, &dev_attr_temp3_input);
 328         device_create_file(&new_client->dev, &dev_attr_temp4_input);
 329         device_create_file(&new_client->dev, &dev_attr_temp1_max);
 330         device_create_file(&new_client->dev, &dev_attr_temp2_max);
 331         device_create_file(&new_client->dev, &dev_attr_temp3_max);
 332         device_create_file(&new_client->dev, &dev_attr_temp4_max);
 333         device_create_file(&new_client->dev, &dev_attr_temp1_crit);
 334         device_create_file(&new_client->dev, &dev_attr_temp2_crit);
 335         device_create_file(&new_client->dev, &dev_attr_temp3_crit);
 336         device_create_file(&new_client->dev, &dev_attr_temp4_crit);
 337         device_create_file(&new_client->dev, &dev_attr_alarms);
 338
 339         return 0;
 340
 341 exit_free:
 342         kfree(data);
 343 exit:
 344         return err;
 345 }
 346
 347 static int lm83_detach_client(struct i2c_client *client)
 348 {
 349         int err;
 350
 351         if ((err = i2c_detach_client(client))) {
 352                 dev_err(&client->dev,
 353                     "Client deregistration failed, client not detached.\n");
 354                 return err;
 355         }
 356
 357         kfree(i2c_get_clientdata(client));
 358         return 0;
 359 }
 360
 361 static struct lm83_data *lm83_update_device(struct device *dev)
 362 {
 363         struct i2c_client *client = to_i2c_client(dev);
 364         struct lm83_data *data = i2c_get_clientdata(client);
 365
 366         down(&data->update_lock);
 367
 368         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 369                 int nr;
 370
 371                 dev_dbg(&client->dev, "Updating lm83 data.\n");
 372                 for (nr = 0; nr < 4 ; nr++) {
 373                         data->temp_input[nr] =
 374                             i2c_smbus_read_byte_data(client,
 375                             LM83_REG_R_TEMP[nr]);
 376                         data->temp_high[nr] =
 377                             i2c_smbus_read_byte_data(client,
 378                             LM83_REG_R_HIGH[nr]);
 379                 }
 380                 data->temp_crit =
 381                     i2c_smbus_read_byte_data(client, LM83_REG_R_TCRIT);
 382                 data->alarms =
 383                     i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 384                     + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 385                     << 8);
 386
 387                 data->last_updated = jiffies;
 388                 data->valid = 1;
 389         }
 390
 391         up(&data->update_lock);
 392
 393         return data;
 394 }
 395
 396 static int __init sensors_lm83_init(void)
 397 {
 398         return i2c_add_driver(&lm83_driver);
 399 }
 400
 401 static void __exit sensors_lm83_exit(void)
 402 {
 403         i2c_del_driver(&lm83_driver);
 404 }
 405
 406 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 407 MODULE_DESCRIPTION("LM83 driver");
 408 MODULE_LICENSE("GPL");
 409
 410 module_init(sensors_lm83_init);
 411 module_exit(sensors_lm83_exit);