drivers/hwmon/lm95241.c

   1 /*
   2  * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
   3  *
   4  * The LM95241 is a sensor chip made by National Semiconductors.
   5  * It reports up to three temperatures (its own plus up to two external ones).
   6  * Complete datasheet can be obtained from National's website at:
   7  *   http://www.national.com/ds.cgi/LM/LM95241.pdf
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/jiffies.h>
  28 #include <linux/i2c.h>
  29 #include <linux/hwmon.h>
  30 #include <linux/hwmon-sysfs.h>
  31 #include <linux/err.h>
  32 #include <linux/mutex.h>
  33 #include <linux/sysfs.h>
  34
  35 #define DEVNAME "lm95241"
  36
  37 static const unsigned short normal_i2c[] = {
  38         0x19, 0x2a, 0x2b, I2C_CLIENT_END };
  39
  40 /* LM95241 registers */
  41 #define LM95241_REG_R_MAN_ID            0xFE
  42 #define LM95241_REG_R_CHIP_ID           0xFF
  43 #define LM95241_REG_R_STATUS            0x02
  44 #define LM95241_REG_RW_CONFIG           0x03
  45 #define LM95241_REG_RW_REM_FILTER       0x06
  46 #define LM95241_REG_RW_TRUTHERM         0x07
  47 #define LM95241_REG_W_ONE_SHOT          0x0F
  48 #define LM95241_REG_R_LOCAL_TEMPH       0x10
  49 #define LM95241_REG_R_REMOTE1_TEMPH     0x11
  50 #define LM95241_REG_R_REMOTE2_TEMPH     0x12
  51 #define LM95241_REG_R_LOCAL_TEMPL       0x20
  52 #define LM95241_REG_R_REMOTE1_TEMPL     0x21
  53 #define LM95241_REG_R_REMOTE2_TEMPL     0x22
  54 #define LM95241_REG_RW_REMOTE_MODEL     0x30
  55
  56 /* LM95241 specific bitfields */
  57 #define CFG_STOP 0x40
  58 #define CFG_CR0076 0x00
  59 #define CFG_CR0182 0x10
  60 #define CFG_CR1000 0x20
  61 #define CFG_CR2700 0x30
  62 #define R1MS_SHIFT 0
  63 #define R2MS_SHIFT 2
  64 #define R1MS_MASK (0x01 << (R1MS_SHIFT))
  65 #define R2MS_MASK (0x01 << (R2MS_SHIFT))
  66 #define R1DF_SHIFT 1
  67 #define R2DF_SHIFT 2
  68 #define R1DF_MASK (0x01 << (R1DF_SHIFT))
  69 #define R2DF_MASK (0x01 << (R2DF_SHIFT))
  70 #define R1FE_MASK 0x01
  71 #define R2FE_MASK 0x05
  72 #define TT1_SHIFT 0
  73 #define TT2_SHIFT 4
  74 #define TT_OFF 0
  75 #define TT_ON 1
  76 #define TT_MASK 7
  77 #define MANUFACTURER_ID 0x01
  78 #define DEFAULT_REVISION 0xA4
  79
  80 static const u8 lm95241_reg_address[] = {
  81         LM95241_REG_R_LOCAL_TEMPH,
  82         LM95241_REG_R_LOCAL_TEMPL,
  83         LM95241_REG_R_REMOTE1_TEMPH,
  84         LM95241_REG_R_REMOTE1_TEMPL,
  85         LM95241_REG_R_REMOTE2_TEMPH,
  86         LM95241_REG_R_REMOTE2_TEMPL
  87 };
  88
  89 /* Client data (each client gets its own) */
  90 struct lm95241_data {
  91         struct device *hwmon_dev;
  92         struct mutex update_lock;
  93         unsigned long last_updated, interval;   /* in jiffies */
  94         char valid;             /* zero until following fields are valid */
  95         /* registers values */
  96         u8 temp[ARRAY_SIZE(lm95241_reg_address)];
  97         u8 config, model, trutherm;
  98 };
  99
 100 /* Conversions */
 101 static int TempFromReg(u8 val_h, u8 val_l)
 102 {
 103         if (val_h & 0x80)
 104                 return val_h - 0x100;
 105         return val_h * 1000 + val_l * 1000 / 256;
 106 }
 107
 108 static struct lm95241_data *lm95241_update_device(struct device *dev)
 109 {
 110         struct i2c_client *client = to_i2c_client(dev);
 111         struct lm95241_data *data = i2c_get_clientdata(client);
 112
 113         mutex_lock(&data->update_lock);
 114
 115         if (time_after(jiffies, data->last_updated + data->interval) ||
 116             !data->valid) {
 117                 int i;
 118
 119                 dev_dbg(&client->dev, "Updating lm95241 data.\n");
 120                 for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
 121                         data->temp[i]
 122                           = i2c_smbus_read_byte_data(client,
 123                                                      lm95241_reg_address[i]);
 124                 data->last_updated = jiffies;
 125                 data->valid = 1;
 126         }
 127
 128         mutex_unlock(&data->update_lock);
 129
 130         return data;
 131 }
 132
 133 /* Sysfs stuff */
 134 static ssize_t show_input(struct device *dev, struct device_attribute *attr,
 135                           char *buf)
 136 {
 137         struct lm95241_data *data = lm95241_update_device(dev);
 138
 139         return snprintf(buf, PAGE_SIZE - 1, "%d\n",
 140                 TempFromReg(data->temp[to_sensor_dev_attr(attr)->index],
 141                             data->temp[to_sensor_dev_attr(attr)->index + 1]));
 142 }
 143
 144 static ssize_t show_type(struct device *dev, struct device_attribute *attr,
 145                          char *buf)
 146 {
 147         struct i2c_client *client = to_i2c_client(dev);
 148         struct lm95241_data *data = i2c_get_clientdata(client);
 149
 150         return snprintf(buf, PAGE_SIZE - 1,
 151                 data->model & to_sensor_dev_attr(attr)->index ? "1\n" : "2\n");
 152 }
 153
 154 static ssize_t set_type(struct device *dev, struct device_attribute *attr,
 155                         const char *buf, size_t count)
 156 {
 157         struct i2c_client *client = to_i2c_client(dev);
 158         struct lm95241_data *data = i2c_get_clientdata(client);
 159         unsigned long val;
 160         int shift;
 161         u8 mask = to_sensor_dev_attr(attr)->index;
 162
 163         if (strict_strtoul(buf, 10, &val) < 0)
 164                 return -EINVAL;
 165         if (val != 1 && val != 2)
 166                 return -EINVAL;
 167
 168         shift = mask == R1MS_MASK ? TT1_SHIFT : TT2_SHIFT;
 169
 170         mutex_lock(&data->update_lock);
 171
 172         data->trutherm &= ~(TT_MASK << shift);
 173         if (val == 1) {
 174                 data->model |= mask;
 175                 data->trutherm |= (TT_ON << shift);
 176         } else {
 177                 data->model &= ~mask;
 178                 data->trutherm |= (TT_OFF << shift);
 179         }
 180         data->valid = 0;
 181
 182         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 183                                   data->model);
 184         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 185                                   data->trutherm);
 186
 187         mutex_unlock(&data->update_lock);
 188
 189         return count;
 190 }
 191
 192 static ssize_t show_min(struct device *dev, struct device_attribute *attr,
 193                         char *buf)
 194 {
 195         struct i2c_client *client = to_i2c_client(dev);
 196         struct lm95241_data *data = i2c_get_clientdata(client);
 197
 198         return snprintf(buf, PAGE_SIZE - 1,
 199                         data->config & to_sensor_dev_attr(attr)->index ?
 200                         "-127000\n" : "0\n");
 201 }
 202
 203 static ssize_t set_min(struct device *dev, struct device_attribute *attr,
 204                        const char *buf, size_t count)
 205 {
 206         struct i2c_client *client = to_i2c_client(dev);
 207         struct lm95241_data *data = i2c_get_clientdata(client);
 208         long val;
 209
 210         if (strict_strtol(buf, 10, &val) < 0)
 211                 return -EINVAL;
 212         if (val < -128000)
 213                 return -EINVAL;
 214
 215         mutex_lock(&data->update_lock);
 216
 217         if (val < 0)
 218                 data->config |= to_sensor_dev_attr(attr)->index;
 219         else
 220                 data->config &= ~to_sensor_dev_attr(attr)->index;
 221         data->valid = 0;
 222
 223         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 224
 225         mutex_unlock(&data->update_lock);
 226
 227         return count;
 228 }
 229
 230 static ssize_t show_max(struct device *dev, struct device_attribute *attr,
 231                         char *buf)
 232 {
 233         struct i2c_client *client = to_i2c_client(dev);
 234         struct lm95241_data *data = i2c_get_clientdata(client);
 235
 236         return snprintf(buf, PAGE_SIZE - 1,
 237                         data->config & to_sensor_dev_attr(attr)->index ?
 238                         "127000\n" : "255000\n");
 239 }
 240
 241 static ssize_t set_max(struct device *dev, struct device_attribute *attr,
 242                        const char *buf, size_t count)
 243 {
 244         struct i2c_client *client = to_i2c_client(dev);
 245         struct lm95241_data *data = i2c_get_clientdata(client);
 246         long val;
 247
 248         if (strict_strtol(buf, 10, &val) < 0)
 249                 return -EINVAL;
 250         if (val >= 256000)
 251                 return -EINVAL;
 252
 253         mutex_lock(&data->update_lock);
 254
 255         if (val <= 127000)
 256                 data->config |= to_sensor_dev_attr(attr)->index;
 257         else
 258                 data->config &= ~to_sensor_dev_attr(attr)->index;
 259         data->valid = 0;
 260
 261         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 262
 263         mutex_unlock(&data->update_lock);
 264
 265         return count;
 266 }
 267
 268 static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
 269                              char *buf)
 270 {
 271         struct lm95241_data *data = lm95241_update_device(dev);
 272
 273         return snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->interval
 274                         / HZ);
 275 }
 276
 277 static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
 278                             const char *buf, size_t count)
 279 {
 280         struct i2c_client *client = to_i2c_client(dev);
 281         struct lm95241_data *data = i2c_get_clientdata(client);
 282         unsigned long val;
 283
 284         if (strict_strtoul(buf, 10, &val) < 0)
 285                 return -EINVAL;
 286
 287         data->interval = val * HZ / 1000;
 288
 289         return count;
 290 }
 291
 292 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
 293 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
 294 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 4);
 295 static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type,
 296                           R1MS_MASK);
 297 static SENSOR_DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type, set_type,
 298                           R2MS_MASK);
 299 static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min,
 300                           R1DF_MASK);
 301 static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min,
 302                           R2DF_MASK);
 303 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max,
 304                           R1DF_MASK);
 305 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max,
 306                           R2DF_MASK);
 307 static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
 308                    set_interval);
 309
 310 static struct attribute *lm95241_attributes[] = {
 311         &sensor_dev_attr_temp1_input.dev_attr.attr,
 312         &sensor_dev_attr_temp2_input.dev_attr.attr,
 313         &sensor_dev_attr_temp3_input.dev_attr.attr,
 314         &sensor_dev_attr_temp2_type.dev_attr.attr,
 315         &sensor_dev_attr_temp3_type.dev_attr.attr,
 316         &sensor_dev_attr_temp2_min.dev_attr.attr,
 317         &sensor_dev_attr_temp3_min.dev_attr.attr,
 318         &sensor_dev_attr_temp2_max.dev_attr.attr,
 319         &sensor_dev_attr_temp3_max.dev_attr.attr,
 320         &dev_attr_update_interval.attr,
 321         NULL
 322 };
 323
 324 static const struct attribute_group lm95241_group = {
 325         .attrs = lm95241_attributes,
 326 };
 327
 328 /* Return 0 if detection is successful, -ENODEV otherwise */
 329 static int lm95241_detect(struct i2c_client *new_client,
 330                           struct i2c_board_info *info)
 331 {
 332         struct i2c_adapter *adapter = new_client->adapter;
 333         int address = new_client->addr;
 334         const char *name;
 335
 336         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 337                 return -ENODEV;
 338
 339         if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID)
 340              == MANUFACTURER_ID)
 341             && (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID)
 342                 >= DEFAULT_REVISION)) {
 343                 name = DEVNAME;
 344         } else {
 345                 dev_dbg(&adapter->dev, "LM95241 detection failed at 0x%02x\n",
 346                         address);
 347                 return -ENODEV;
 348         }
 349
 350         /* Fill the i2c board info */
 351         strlcpy(info->type, name, I2C_NAME_SIZE);
 352         return 0;
 353 }
 354
 355 static void lm95241_init_client(struct i2c_client *client)
 356 {
 357         struct lm95241_data *data = i2c_get_clientdata(client);
 358
 359         data->interval = HZ;    /* 1 sec default */
 360         data->valid = 0;
 361         data->config = CFG_CR0076;
 362         data->model = 0;
 363         data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
 364
 365         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 366         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
 367                                   R1FE_MASK | R2FE_MASK);
 368         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 369                                   data->trutherm);
 370         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 371                                   data->model);
 372 }
 373
 374 static int lm95241_probe(struct i2c_client *new_client,
 375                          const struct i2c_device_id *id)
 376 {
 377         struct lm95241_data *data;
 378         int err;
 379
 380         data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
 381         if (!data) {
 382                 err = -ENOMEM;
 383                 goto exit;
 384         }
 385
 386         i2c_set_clientdata(new_client, data);
 387         mutex_init(&data->update_lock);
 388
 389         /* Initialize the LM95241 chip */
 390         lm95241_init_client(new_client);
 391
 392         /* Register sysfs hooks */
 393         err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group);
 394         if (err)
 395                 goto exit_free;
 396
 397         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 398         if (IS_ERR(data->hwmon_dev)) {
 399                 err = PTR_ERR(data->hwmon_dev);
 400                 goto exit_remove_files;
 401         }
 402
 403         return 0;
 404
 405 exit_remove_files:
 406         sysfs_remove_group(&new_client->dev.kobj, &lm95241_group);
 407 exit_free:
 408         kfree(data);
 409 exit:
 410         return err;
 411 }
 412
 413 static int lm95241_remove(struct i2c_client *client)
 414 {
 415         struct lm95241_data *data = i2c_get_clientdata(client);
 416
 417         hwmon_device_unregister(data->hwmon_dev);
 418         sysfs_remove_group(&client->dev.kobj, &lm95241_group);
 419
 420         kfree(data);
 421         return 0;
 422 }
 423
 424 /* Driver data (common to all clients) */
 425 static const struct i2c_device_id lm95241_id[] = {
 426         { DEVNAME, 0 },
 427         { }
 428 };
 429 MODULE_DEVICE_TABLE(i2c, lm95241_id);
 430
 431 static struct i2c_driver lm95241_driver = {
 432         .class          = I2C_CLASS_HWMON,
 433         .driver = {
 434                 .name   = DEVNAME,
 435         },
 436         .probe          = lm95241_probe,
 437         .remove         = lm95241_remove,
 438         .id_table       = lm95241_id,
 439         .detect         = lm95241_detect,
 440         .address_list   = normal_i2c,
 441 };
 442
 443 static int __init sensors_lm95241_init(void)
 444 {
 445         return i2c_add_driver(&lm95241_driver);
 446 }
 447
 448 static void __exit sensors_lm95241_exit(void)
 449 {
 450         i2c_del_driver(&lm95241_driver);
 451 }
 452
 453 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
 454 MODULE_DESCRIPTION("LM95241 sensor driver");
 455 MODULE_LICENSE("GPL");
 456
 457 module_init(sensors_lm95241_init);
 458 module_exit(sensors_lm95241_exit);