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 temp_from_reg_signed(u8 val_h, u8 val_l)
 102 {
 103         s16 val_hl = (val_h << 8) | val_l;
 104         return val_hl * 1000 / 256;
 105 }
 106
 107 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
 108 {
 109         u16 val_hl = (val_h << 8) | val_l;
 110         return val_hl * 1000 / 256;
 111 }
 112
 113 static struct lm95241_data *lm95241_update_device(struct device *dev)
 114 {
 115         struct i2c_client *client = to_i2c_client(dev);
 116         struct lm95241_data *data = i2c_get_clientdata(client);
 117
 118         mutex_lock(&data->update_lock);
 119
 120         if (time_after(jiffies, data->last_updated + data->interval) ||
 121             !data->valid) {
 122                 int i;
 123
 124                 dev_dbg(&client->dev, "Updating lm95241 data.\n");
 125                 for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
 126                         data->temp[i]
 127                           = i2c_smbus_read_byte_data(client,
 128                                                      lm95241_reg_address[i]);
 129                 data->last_updated = jiffies;
 130                 data->valid = 1;
 131         }
 132
 133         mutex_unlock(&data->update_lock);
 134
 135         return data;
 136 }
 137
 138 /* Sysfs stuff */
 139 static ssize_t show_input(struct device *dev, struct device_attribute *attr,
 140                           char *buf)
 141 {
 142         struct lm95241_data *data = lm95241_update_device(dev);
 143         int index = to_sensor_dev_attr(attr)->index;
 144
 145         return snprintf(buf, PAGE_SIZE - 1, "%d\n",
 146                         index == 0 || (data->config & (1 << (index / 2))) ?
 147                 temp_from_reg_signed(data->temp[index], data->temp[index + 1]) :
 148                 temp_from_reg_unsigned(data->temp[index],
 149                                        data->temp[index + 1]));
 150 }
 151
 152 static ssize_t show_type(struct device *dev, struct device_attribute *attr,
 153                          char *buf)
 154 {
 155         struct i2c_client *client = to_i2c_client(dev);
 156         struct lm95241_data *data = i2c_get_clientdata(client);
 157
 158         return snprintf(buf, PAGE_SIZE - 1,
 159                 data->model & to_sensor_dev_attr(attr)->index ? "1\n" : "2\n");
 160 }
 161
 162 static ssize_t set_type(struct device *dev, struct device_attribute *attr,
 163                         const char *buf, size_t count)
 164 {
 165         struct i2c_client *client = to_i2c_client(dev);
 166         struct lm95241_data *data = i2c_get_clientdata(client);
 167         unsigned long val;
 168         int shift;
 169         u8 mask = to_sensor_dev_attr(attr)->index;
 170
 171         if (strict_strtoul(buf, 10, &val) < 0)
 172                 return -EINVAL;
 173         if (val != 1 && val != 2)
 174                 return -EINVAL;
 175
 176         shift = mask == R1MS_MASK ? TT1_SHIFT : TT2_SHIFT;
 177
 178         mutex_lock(&data->update_lock);
 179
 180         data->trutherm &= ~(TT_MASK << shift);
 181         if (val == 1) {
 182                 data->model |= mask;
 183                 data->trutherm |= (TT_ON << shift);
 184         } else {
 185                 data->model &= ~mask;
 186                 data->trutherm |= (TT_OFF << shift);
 187         }
 188         data->valid = 0;
 189
 190         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 191                                   data->model);
 192         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 193                                   data->trutherm);
 194
 195         mutex_unlock(&data->update_lock);
 196
 197         return count;
 198 }
 199
 200 static ssize_t show_min(struct device *dev, struct device_attribute *attr,
 201                         char *buf)
 202 {
 203         struct i2c_client *client = to_i2c_client(dev);
 204         struct lm95241_data *data = i2c_get_clientdata(client);
 205
 206         return snprintf(buf, PAGE_SIZE - 1,
 207                         data->config & to_sensor_dev_attr(attr)->index ?
 208                         "-127000\n" : "0\n");
 209 }
 210
 211 static ssize_t set_min(struct device *dev, struct device_attribute *attr,
 212                        const char *buf, size_t count)
 213 {
 214         struct i2c_client *client = to_i2c_client(dev);
 215         struct lm95241_data *data = i2c_get_clientdata(client);
 216         long val;
 217
 218         if (strict_strtol(buf, 10, &val) < 0)
 219                 return -EINVAL;
 220         if (val < -128000)
 221                 return -EINVAL;
 222
 223         mutex_lock(&data->update_lock);
 224
 225         if (val < 0)
 226                 data->config |= to_sensor_dev_attr(attr)->index;
 227         else
 228                 data->config &= ~to_sensor_dev_attr(attr)->index;
 229         data->valid = 0;
 230
 231         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 232
 233         mutex_unlock(&data->update_lock);
 234
 235         return count;
 236 }
 237
 238 static ssize_t show_max(struct device *dev, struct device_attribute *attr,
 239                         char *buf)
 240 {
 241         struct i2c_client *client = to_i2c_client(dev);
 242         struct lm95241_data *data = i2c_get_clientdata(client);
 243
 244         return snprintf(buf, PAGE_SIZE - 1,
 245                         data->config & to_sensor_dev_attr(attr)->index ?
 246                         "127000\n" : "255000\n");
 247 }
 248
 249 static ssize_t set_max(struct device *dev, struct device_attribute *attr,
 250                        const char *buf, size_t count)
 251 {
 252         struct i2c_client *client = to_i2c_client(dev);
 253         struct lm95241_data *data = i2c_get_clientdata(client);
 254         long val;
 255
 256         if (strict_strtol(buf, 10, &val) < 0)
 257                 return -EINVAL;
 258         if (val >= 256000)
 259                 return -EINVAL;
 260
 261         mutex_lock(&data->update_lock);
 262
 263         if (val <= 127000)
 264                 data->config |= to_sensor_dev_attr(attr)->index;
 265         else
 266                 data->config &= ~to_sensor_dev_attr(attr)->index;
 267         data->valid = 0;
 268
 269         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 270
 271         mutex_unlock(&data->update_lock);
 272
 273         return count;
 274 }
 275
 276 static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
 277                              char *buf)
 278 {
 279         struct lm95241_data *data = lm95241_update_device(dev);
 280
 281         return snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->interval
 282                         / HZ);
 283 }
 284
 285 static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
 286                             const char *buf, size_t count)
 287 {
 288         struct i2c_client *client = to_i2c_client(dev);
 289         struct lm95241_data *data = i2c_get_clientdata(client);
 290         unsigned long val;
 291
 292         if (strict_strtoul(buf, 10, &val) < 0)
 293                 return -EINVAL;
 294
 295         data->interval = val * HZ / 1000;
 296
 297         return count;
 298 }
 299
 300 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
 301 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
 302 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 4);
 303 static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type,
 304                           R1MS_MASK);
 305 static SENSOR_DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type, set_type,
 306                           R2MS_MASK);
 307 static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min,
 308                           R1DF_MASK);
 309 static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min,
 310                           R2DF_MASK);
 311 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max,
 312                           R1DF_MASK);
 313 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max,
 314                           R2DF_MASK);
 315 static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
 316                    set_interval);
 317
 318 static struct attribute *lm95241_attributes[] = {
 319         &sensor_dev_attr_temp1_input.dev_attr.attr,
 320         &sensor_dev_attr_temp2_input.dev_attr.attr,
 321         &sensor_dev_attr_temp3_input.dev_attr.attr,
 322         &sensor_dev_attr_temp2_type.dev_attr.attr,
 323         &sensor_dev_attr_temp3_type.dev_attr.attr,
 324         &sensor_dev_attr_temp2_min.dev_attr.attr,
 325         &sensor_dev_attr_temp3_min.dev_attr.attr,
 326         &sensor_dev_attr_temp2_max.dev_attr.attr,
 327         &sensor_dev_attr_temp3_max.dev_attr.attr,
 328         &dev_attr_update_interval.attr,
 329         NULL
 330 };
 331
 332 static const struct attribute_group lm95241_group = {
 333         .attrs = lm95241_attributes,
 334 };
 335
 336 /* Return 0 if detection is successful, -ENODEV otherwise */
 337 static int lm95241_detect(struct i2c_client *new_client,
 338                           struct i2c_board_info *info)
 339 {
 340         struct i2c_adapter *adapter = new_client->adapter;
 341         int address = new_client->addr;
 342         const char *name;
 343
 344         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 345                 return -ENODEV;
 346
 347         if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID)
 348              == MANUFACTURER_ID)
 349             && (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID)
 350                 == DEFAULT_REVISION)) {
 351                 name = DEVNAME;
 352         } else {
 353                 dev_dbg(&adapter->dev, "LM95241 detection failed at 0x%02x\n",
 354                         address);
 355                 return -ENODEV;
 356         }
 357
 358         /* Fill the i2c board info */
 359         strlcpy(info->type, name, I2C_NAME_SIZE);
 360         return 0;
 361 }
 362
 363 static void lm95241_init_client(struct i2c_client *client)
 364 {
 365         struct lm95241_data *data = i2c_get_clientdata(client);
 366
 367         data->interval = HZ;    /* 1 sec default */
 368         data->valid = 0;
 369         data->config = CFG_CR0076;
 370         data->model = 0;
 371         data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
 372
 373         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 374         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
 375                                   R1FE_MASK | R2FE_MASK);
 376         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 377                                   data->trutherm);
 378         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 379                                   data->model);
 380 }
 381
 382 static int lm95241_probe(struct i2c_client *new_client,
 383                          const struct i2c_device_id *id)
 384 {
 385         struct lm95241_data *data;
 386         int err;
 387
 388         data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
 389         if (!data) {
 390                 err = -ENOMEM;
 391                 goto exit;
 392         }
 393
 394         i2c_set_clientdata(new_client, data);
 395         mutex_init(&data->update_lock);
 396
 397         /* Initialize the LM95241 chip */
 398         lm95241_init_client(new_client);
 399
 400         /* Register sysfs hooks */
 401         err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group);
 402         if (err)
 403                 goto exit_free;
 404
 405         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 406         if (IS_ERR(data->hwmon_dev)) {
 407                 err = PTR_ERR(data->hwmon_dev);
 408                 goto exit_remove_files;
 409         }
 410
 411         return 0;
 412
 413 exit_remove_files:
 414         sysfs_remove_group(&new_client->dev.kobj, &lm95241_group);
 415 exit_free:
 416         kfree(data);
 417 exit:
 418         return err;
 419 }
 420
 421 static int lm95241_remove(struct i2c_client *client)
 422 {
 423         struct lm95241_data *data = i2c_get_clientdata(client);
 424
 425         hwmon_device_unregister(data->hwmon_dev);
 426         sysfs_remove_group(&client->dev.kobj, &lm95241_group);
 427
 428         kfree(data);
 429         return 0;
 430 }
 431
 432 /* Driver data (common to all clients) */
 433 static const struct i2c_device_id lm95241_id[] = {
 434         { DEVNAME, 0 },
 435         { }
 436 };
 437 MODULE_DEVICE_TABLE(i2c, lm95241_id);
 438
 439 static struct i2c_driver lm95241_driver = {
 440         .class          = I2C_CLASS_HWMON,
 441         .driver = {
 442                 .name   = DEVNAME,
 443         },
 444         .probe          = lm95241_probe,
 445         .remove         = lm95241_remove,
 446         .id_table       = lm95241_id,
 447         .detect         = lm95241_detect,
 448         .address_list   = normal_i2c,
 449 };
 450
 451 static int __init sensors_lm95241_init(void)
 452 {
 453         return i2c_add_driver(&lm95241_driver);
 454 }
 455
 456 static void __exit sensors_lm95241_exit(void)
 457 {
 458         i2c_del_driver(&lm95241_driver);
 459 }
 460
 461 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
 462 MODULE_DESCRIPTION("LM95241 sensor driver");
 463 MODULE_LICENSE("GPL");
 464
 465 module_init(sensors_lm95241_init);
 466 module_exit(sensors_lm95241_exit);