drivers/i2c/chips/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
  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 Celsius.
  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         LM83_REG_R_LOCAL_HIGH,
  99         LM83_REG_R_REMOTE1_HIGH,
 100         LM83_REG_R_REMOTE2_HIGH,
 101         LM83_REG_R_REMOTE3_HIGH,
 102         LM83_REG_R_TCRIT,
 103 };
 104
 105 static const u8 LM83_REG_W_HIGH[] = {
 106         LM83_REG_W_LOCAL_HIGH,
 107         LM83_REG_W_REMOTE1_HIGH,
 108         LM83_REG_W_REMOTE2_HIGH,
 109         LM83_REG_W_REMOTE3_HIGH,
 110         LM83_REG_W_TCRIT,
 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[9];     /* 0..3: input 1-4,
 147                            4..7: high limit 1-4,
 148                            8   : critical limit */
 149         u16 alarms; /* bitvector, combined */
 150 };
 151
 152 /*
 153  * Sysfs stuff
 154  */
 155
 156 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 157                          char *buf)
 158 {
 159         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 160         struct lm83_data *data = lm83_update_device(dev);
 161         return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 162 }
 163
 164 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 165                         const char *buf, size_t count)
 166 {
 167         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 168         struct i2c_client *client = to_i2c_client(dev);
 169         struct lm83_data *data = i2c_get_clientdata(client);
 170         long val = simple_strtol(buf, NULL, 10);
 171         int nr = attr->index;
 172
 173         down(&data->update_lock);
 174         data->temp[nr] = TEMP_TO_REG(val);
 175         i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
 176                                   data->temp[nr]);
 177         up(&data->update_lock);
 178         return count;
 179 }
 180
 181 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
 182                            char *buf)
 183 {
 184         struct lm83_data *data = lm83_update_device(dev);
 185         return sprintf(buf, "%d\n", data->alarms);
 186 }
 187
 188 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 189 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
 190 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
 191 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
 192 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
 193         set_temp, 4);
 194 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
 195         set_temp, 5);
 196 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
 197         set_temp, 6);
 198 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
 199         set_temp, 7);
 200 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
 201 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
 202 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
 203         set_temp, 8);
 204 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
 205 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 206
 207 /*
 208  * Real code
 209  */
 210
 211 static int lm83_attach_adapter(struct i2c_adapter *adapter)
 212 {
 213         if (!(adapter->class & I2C_CLASS_HWMON))
 214                 return 0;
 215         return i2c_detect(adapter, &addr_data, lm83_detect);
 216 }
 217
 218 /*
 219  * The following function does more than just detection. If detection
 220  * succeeds, it also registers the new chip.
 221  */
 222 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
 223 {
 224         struct i2c_client *new_client;
 225         struct lm83_data *data;
 226         int err = 0;
 227         const char *name = "";
 228
 229         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 230                 goto exit;
 231
 232         if (!(data = kmalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
 233                 err = -ENOMEM;
 234                 goto exit;
 235         }
 236         memset(data, 0, sizeof(struct lm83_data));
 237
 238         /* The common I2C client data is placed right after the
 239          * LM83-specific data. */
 240         new_client = &data->client;
 241         i2c_set_clientdata(new_client, data);
 242         new_client->addr = address;
 243         new_client->adapter = adapter;
 244         new_client->driver = &lm83_driver;
 245         new_client->flags = 0;
 246
 247         /* Now we do the detection and identification. A negative kind
 248          * means that the driver was loaded with no force parameter
 249          * (default), so we must both detect and identify the chip
 250          * (actually there is only one possible kind of chip for now, LM83).
 251          * A zero kind means that the driver was loaded with the force
 252          * parameter, the detection step shall be skipped. A positive kind
 253          * means that the driver was loaded with the force parameter and a
 254          * given kind of chip is requested, so both the detection and the
 255          * identification steps are skipped. */
 256
 257         /* Default to an LM83 if forced */
 258         if (kind == 0)
 259                 kind = lm83;
 260
 261         if (kind < 0) { /* detection */
 262                 if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
 263                     & 0xA8) != 0x00) ||
 264                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
 265                     & 0x48) != 0x00) ||
 266                     ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
 267                     & 0x41) != 0x00)) {
 268                         dev_dbg(&adapter->dev,
 269                             "LM83 detection failed at 0x%02x.\n", address);
 270                         goto exit_free;
 271                 }
 272         }
 273
 274         if (kind <= 0) { /* identification */
 275                 u8 man_id, chip_id;
 276
 277                 man_id = i2c_smbus_read_byte_data(new_client,
 278                     LM83_REG_R_MAN_ID);
 279                 chip_id = i2c_smbus_read_byte_data(new_client,
 280                     LM83_REG_R_CHIP_ID);
 281
 282                 if (man_id == 0x01) { /* National Semiconductor */
 283                         if (chip_id == 0x03) {
 284                                 kind = lm83;
 285                         }
 286                 }
 287
 288                 if (kind <= 0) { /* identification failed */
 289                         dev_info(&adapter->dev,
 290                             "Unsupported chip (man_id=0x%02X, "
 291                             "chip_id=0x%02X).\n", man_id, chip_id);
 292                         goto exit_free;
 293                 }
 294         }
 295
 296         if (kind == lm83) {
 297                 name = "lm83";
 298         }
 299
 300         /* We can fill in the remaining client fields */
 301         strlcpy(new_client->name, name, I2C_NAME_SIZE);
 302         data->valid = 0;
 303         init_MUTEX(&data->update_lock);
 304
 305         /* Tell the I2C layer a new client has arrived */
 306         if ((err = i2c_attach_client(new_client)))
 307                 goto exit_free;
 308
 309         /*
 310          * Initialize the LM83 chip
 311          * (Nothing to do for this one.)
 312          */
 313
 314         /* Register sysfs hooks */
 315         device_create_file(&new_client->dev,
 316                            &sensor_dev_attr_temp1_input.dev_attr);
 317         device_create_file(&new_client->dev,
 318                            &sensor_dev_attr_temp2_input.dev_attr);
 319         device_create_file(&new_client->dev,
 320                            &sensor_dev_attr_temp3_input.dev_attr);
 321         device_create_file(&new_client->dev,
 322                            &sensor_dev_attr_temp4_input.dev_attr);
 323         device_create_file(&new_client->dev,
 324                            &sensor_dev_attr_temp1_max.dev_attr);
 325         device_create_file(&new_client->dev,
 326                            &sensor_dev_attr_temp2_max.dev_attr);
 327         device_create_file(&new_client->dev,
 328                            &sensor_dev_attr_temp3_max.dev_attr);
 329         device_create_file(&new_client->dev,
 330                            &sensor_dev_attr_temp4_max.dev_attr);
 331         device_create_file(&new_client->dev,
 332                            &sensor_dev_attr_temp1_crit.dev_attr);
 333         device_create_file(&new_client->dev,
 334                            &sensor_dev_attr_temp2_crit.dev_attr);
 335         device_create_file(&new_client->dev,
 336                            &sensor_dev_attr_temp3_crit.dev_attr);
 337         device_create_file(&new_client->dev,
 338                            &sensor_dev_attr_temp4_crit.dev_attr);
 339         device_create_file(&new_client->dev, &dev_attr_alarms);
 340
 341         return 0;
 342
 343 exit_free:
 344         kfree(data);
 345 exit:
 346         return err;
 347 }
 348
 349 static int lm83_detach_client(struct i2c_client *client)
 350 {
 351         int err;
 352
 353         if ((err = i2c_detach_client(client))) {
 354                 dev_err(&client->dev,
 355                     "Client deregistration failed, client not detached.\n");
 356                 return err;
 357         }
 358
 359         kfree(i2c_get_clientdata(client));
 360         return 0;
 361 }
 362
 363 static struct lm83_data *lm83_update_device(struct device *dev)
 364 {
 365         struct i2c_client *client = to_i2c_client(dev);
 366         struct lm83_data *data = i2c_get_clientdata(client);
 367
 368         down(&data->update_lock);
 369
 370         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 371                 int nr;
 372
 373                 dev_dbg(&client->dev, "Updating lm83 data.\n");
 374                 for (nr = 0; nr < 9; nr++) {
 375                         data->temp[nr] =
 376                             i2c_smbus_read_byte_data(client,
 377                             LM83_REG_R_TEMP[nr]);
 378                 }
 379                 data->alarms =
 380                     i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 381                     + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 382                     << 8);
 383
 384                 data->last_updated = jiffies;
 385                 data->valid = 1;
 386         }
 387
 388         up(&data->update_lock);
 389
 390         return data;
 391 }
 392
 393 static int __init sensors_lm83_init(void)
 394 {
 395         return i2c_add_driver(&lm83_driver);
 396 }
 397
 398 static void __exit sensors_lm83_exit(void)
 399 {
 400         i2c_del_driver(&lm83_driver);
 401 }
 402
 403 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 404 MODULE_DESCRIPTION("LM83 driver");
 405 MODULE_LICENSE("GPL");
 406
 407 module_init(sensors_lm83_init);
 408 module_exit(sensors_lm83_exit);