drivers/hwmon/lm83.c

   1 /*
   2  * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
   3  *          monitoring
   4  * Copyright (C) 2003-2009  Jean Delvare <jdelvare@suse.de>
   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  * Also supports the LM82 temp sensor, which is basically a stripped down
  16  * model of the LM83.  Datasheet is here:
  17  * http://www.national.com/pf/LM/LM82.html
  18  *
  19  * This program is free software; you can redistribute it and/or modify
  20  * it under the terms of the GNU General Public License as published by
  21  * the Free Software Foundation; either version 2 of the License, or
  22  * (at your option) any later version.
  23  *
  24  * This program is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  * GNU General Public License for more details.
  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 #include <linux/sysfs.h>
  40
  41 /*
  42  * Addresses to scan
  43  * Address is selected using 2 three-level pins, resulting in 9 possible
  44  * addresses.
  45  */
  46
  47 static const unsigned short normal_i2c[] = {
  48         0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
  49
  50 enum chips { lm83, lm82 };
  51
  52 /*
  53  * The LM83 registers
  54  * Manufacturer ID is 0x01 for National Semiconductor.
  55  */
  56
  57 #define LM83_REG_R_MAN_ID               0xFE
  58 #define LM83_REG_R_CHIP_ID              0xFF
  59 #define LM83_REG_R_CONFIG               0x03
  60 #define LM83_REG_W_CONFIG               0x09
  61 #define LM83_REG_R_STATUS1              0x02
  62 #define LM83_REG_R_STATUS2              0x35
  63 #define LM83_REG_R_LOCAL_TEMP           0x00
  64 #define LM83_REG_R_LOCAL_HIGH           0x05
  65 #define LM83_REG_W_LOCAL_HIGH           0x0B
  66 #define LM83_REG_R_REMOTE1_TEMP         0x30
  67 #define LM83_REG_R_REMOTE1_HIGH         0x38
  68 #define LM83_REG_W_REMOTE1_HIGH         0x50
  69 #define LM83_REG_R_REMOTE2_TEMP         0x01
  70 #define LM83_REG_R_REMOTE2_HIGH         0x07
  71 #define LM83_REG_W_REMOTE2_HIGH         0x0D
  72 #define LM83_REG_R_REMOTE3_TEMP         0x31
  73 #define LM83_REG_R_REMOTE3_HIGH         0x3A
  74 #define LM83_REG_W_REMOTE3_HIGH         0x52
  75 #define LM83_REG_R_TCRIT                0x42
  76 #define LM83_REG_W_TCRIT                0x5A
  77
  78 /*
  79  * Conversions and various macros
  80  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
  81  */
  82
  83 #define TEMP_FROM_REG(val)      ((val) * 1000)
  84 #define TEMP_TO_REG(val)        ((val) <= -128000 ? -128 : \
  85                                  (val) >= 127000 ? 127 : \
  86                                  (val) < 0 ? ((val) - 500) / 1000 : \
  87                                  ((val) + 500) / 1000)
  88
  89 static const u8 LM83_REG_R_TEMP[] = {
  90         LM83_REG_R_LOCAL_TEMP,
  91         LM83_REG_R_REMOTE1_TEMP,
  92         LM83_REG_R_REMOTE2_TEMP,
  93         LM83_REG_R_REMOTE3_TEMP,
  94         LM83_REG_R_LOCAL_HIGH,
  95         LM83_REG_R_REMOTE1_HIGH,
  96         LM83_REG_R_REMOTE2_HIGH,
  97         LM83_REG_R_REMOTE3_HIGH,
  98         LM83_REG_R_TCRIT,
  99 };
 100
 101 static const u8 LM83_REG_W_HIGH[] = {
 102         LM83_REG_W_LOCAL_HIGH,
 103         LM83_REG_W_REMOTE1_HIGH,
 104         LM83_REG_W_REMOTE2_HIGH,
 105         LM83_REG_W_REMOTE3_HIGH,
 106         LM83_REG_W_TCRIT,
 107 };
 108
 109 /*
 110  * Client data (each client gets its own)
 111  */
 112
 113 struct lm83_data {
 114         struct i2c_client *client;
 115         const struct attribute_group *groups[3];
 116         struct mutex update_lock;
 117         char valid; /* zero until following fields are valid */
 118         unsigned long last_updated; /* in jiffies */
 119
 120         /* registers values */
 121         s8 temp[9];     /* 0..3: input 1-4,
 122                            4..7: high limit 1-4,
 123                            8   : critical limit */
 124         u16 alarms; /* bitvector, combined */
 125 };
 126
 127 static struct lm83_data *lm83_update_device(struct device *dev)
 128 {
 129         struct lm83_data *data = dev_get_drvdata(dev);
 130         struct i2c_client *client = data->client;
 131
 132         mutex_lock(&data->update_lock);
 133
 134         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 135                 int nr;
 136
 137                 dev_dbg(&client->dev, "Updating lm83 data.\n");
 138                 for (nr = 0; nr < 9; nr++) {
 139                         data->temp[nr] =
 140                             i2c_smbus_read_byte_data(client,
 141                             LM83_REG_R_TEMP[nr]);
 142                 }
 143                 data->alarms =
 144                     i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 145                     + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 146                     << 8);
 147
 148                 data->last_updated = jiffies;
 149                 data->valid = 1;
 150         }
 151
 152         mutex_unlock(&data->update_lock);
 153
 154         return data;
 155 }
 156
 157 /*
 158  * Sysfs stuff
 159  */
 160
 161 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 162                          char *buf)
 163 {
 164         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 165         struct lm83_data *data = lm83_update_device(dev);
 166         return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 167 }
 168
 169 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 170                         const char *buf, size_t count)
 171 {
 172         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 173         struct lm83_data *data = dev_get_drvdata(dev);
 174         struct i2c_client *client = data->client;
 175         long val;
 176         int nr = attr->index;
 177         int err;
 178
 179         err = kstrtol(buf, 10, &val);
 180         if (err < 0)
 181                 return err;
 182
 183         mutex_lock(&data->update_lock);
 184         data->temp[nr] = TEMP_TO_REG(val);
 185         i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
 186                                   data->temp[nr]);
 187         mutex_unlock(&data->update_lock);
 188         return count;
 189 }
 190
 191 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
 192                            char *buf)
 193 {
 194         struct lm83_data *data = lm83_update_device(dev);
 195         return sprintf(buf, "%d\n", data->alarms);
 196 }
 197
 198 static ssize_t show_alarm(struct device *dev, struct device_attribute
 199                           *devattr, char *buf)
 200 {
 201         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 202         struct lm83_data *data = lm83_update_device(dev);
 203         int bitnr = attr->index;
 204
 205         return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
 206 }
 207
 208 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 209 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
 210 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
 211 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
 212 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
 213         set_temp, 4);
 214 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
 215         set_temp, 5);
 216 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
 217         set_temp, 6);
 218 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
 219         set_temp, 7);
 220 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
 221 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
 222 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
 223         set_temp, 8);
 224 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
 225
 226 /* Individual alarm files */
 227 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
 228 static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
 229 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 2);
 230 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4);
 231 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
 232 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 8);
 233 static SENSOR_DEVICE_ATTR(temp4_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
 234 static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_alarm, NULL, 10);
 235 static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 12);
 236 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 13);
 237 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 15);
 238 /* Raw alarm file for compatibility */
 239 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 240
 241 static struct attribute *lm83_attributes[] = {
 242         &sensor_dev_attr_temp1_input.dev_attr.attr,
 243         &sensor_dev_attr_temp3_input.dev_attr.attr,
 244         &sensor_dev_attr_temp1_max.dev_attr.attr,
 245         &sensor_dev_attr_temp3_max.dev_attr.attr,
 246         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 247         &sensor_dev_attr_temp3_crit.dev_attr.attr,
 248
 249         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 250         &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
 251         &sensor_dev_attr_temp3_fault.dev_attr.attr,
 252         &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 253         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 254         &dev_attr_alarms.attr,
 255         NULL
 256 };
 257
 258 static const struct attribute_group lm83_group = {
 259         .attrs = lm83_attributes,
 260 };
 261
 262 static struct attribute *lm83_attributes_opt[] = {
 263         &sensor_dev_attr_temp2_input.dev_attr.attr,
 264         &sensor_dev_attr_temp4_input.dev_attr.attr,
 265         &sensor_dev_attr_temp2_max.dev_attr.attr,
 266         &sensor_dev_attr_temp4_max.dev_attr.attr,
 267         &sensor_dev_attr_temp2_crit.dev_attr.attr,
 268         &sensor_dev_attr_temp4_crit.dev_attr.attr,
 269
 270         &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 271         &sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
 272         &sensor_dev_attr_temp4_fault.dev_attr.attr,
 273         &sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
 274         &sensor_dev_attr_temp2_fault.dev_attr.attr,
 275         &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 276         NULL
 277 };
 278
 279 static const struct attribute_group lm83_group_opt = {
 280         .attrs = lm83_attributes_opt,
 281 };
 282
 283 /*
 284  * Real code
 285  */
 286
 287 /* Return 0 if detection is successful, -ENODEV otherwise */
 288 static int lm83_detect(struct i2c_client *new_client,
 289                        struct i2c_board_info *info)
 290 {
 291         struct i2c_adapter *adapter = new_client->adapter;
 292         const char *name;
 293         u8 man_id, chip_id;
 294
 295         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 296                 return -ENODEV;
 297
 298         /* Detection */
 299         if ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1) & 0xA8) ||
 300             (i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2) & 0x48) ||
 301             (i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG) & 0x41)) {
 302                 dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
 303                         new_client->addr);
 304                 return -ENODEV;
 305         }
 306
 307         /* Identification */
 308         man_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_MAN_ID);
 309         if (man_id != 0x01)     /* National Semiconductor */
 310                 return -ENODEV;
 311
 312         chip_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_CHIP_ID);
 313         switch (chip_id) {
 314         case 0x03:
 315                 name = "lm83";
 316                 break;
 317         case 0x01:
 318                 name = "lm82";
 319                 break;
 320         default:
 321                 /* identification failed */
 322                 dev_info(&adapter->dev,
 323                          "Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
 324                          man_id, chip_id);
 325                 return -ENODEV;
 326         }
 327
 328         strlcpy(info->type, name, I2C_NAME_SIZE);
 329
 330         return 0;
 331 }
 332
 333 static int lm83_probe(struct i2c_client *new_client,
 334                       const struct i2c_device_id *id)
 335 {
 336         struct device *hwmon_dev;
 337         struct lm83_data *data;
 338
 339         data = devm_kzalloc(&new_client->dev, sizeof(struct lm83_data),
 340                             GFP_KERNEL);
 341         if (!data)
 342                 return -ENOMEM;
 343
 344         data->client = new_client;
 345         mutex_init(&data->update_lock);
 346
 347         /*
 348          * Register sysfs hooks
 349          * The LM82 can only monitor one external diode which is
 350          * at the same register as the LM83 temp3 entry - so we
 351          * declare 1 and 3 common, and then 2 and 4 only for the LM83.
 352          */
 353         data->groups[0] = &lm83_group;
 354         if (id->driver_data == lm83)
 355                 data->groups[1] = &lm83_group_opt;
 356
 357         hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
 358                                                            new_client->name,
 359                                                            data, data->groups);
 360         return PTR_ERR_OR_ZERO(hwmon_dev);
 361 }
 362
 363 /*
 364  * Driver data (common to all clients)
 365  */
 366
 367 static const struct i2c_device_id lm83_id[] = {
 368         { "lm83", lm83 },
 369         { "lm82", lm82 },
 370         { }
 371 };
 372 MODULE_DEVICE_TABLE(i2c, lm83_id);
 373
 374 static struct i2c_driver lm83_driver = {
 375         .class          = I2C_CLASS_HWMON,
 376         .driver = {
 377                 .name   = "lm83",
 378         },
 379         .probe          = lm83_probe,
 380         .id_table       = lm83_id,
 381         .detect         = lm83_detect,
 382         .address_list   = normal_i2c,
 383 };
 384
 385 module_i2c_driver(lm83_driver);
 386
 387 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
 388 MODULE_DESCRIPTION("LM83 driver");
 389 MODULE_LICENSE("GPL");