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 NATSEMI_MAN_ID  0x01
  78 #define LM95231_CHIP_ID 0xA1
  79 #define LM95241_CHIP_ID 0xA4
  80
  81 static const u8 lm95241_reg_address[] = {
  82         LM95241_REG_R_LOCAL_TEMPH,
  83         LM95241_REG_R_LOCAL_TEMPL,
  84         LM95241_REG_R_REMOTE1_TEMPH,
  85         LM95241_REG_R_REMOTE1_TEMPL,
  86         LM95241_REG_R_REMOTE2_TEMPH,
  87         LM95241_REG_R_REMOTE2_TEMPL
  88 };
  89
  90 /* Client data (each client gets its own) */
  91 struct lm95241_data {
  92         struct device *hwmon_dev;
  93         struct mutex update_lock;
  94         unsigned long last_updated, interval;   /* in jiffies */
  95         char valid;             /* zero until following fields are valid */
  96         /* registers values */
  97         u8 temp[ARRAY_SIZE(lm95241_reg_address)];
  98         u8 config, model, trutherm;
  99 };
 100
 101 /* Conversions */
 102 static int temp_from_reg_signed(u8 val_h, u8 val_l)
 103 {
 104         s16 val_hl = (val_h << 8) | val_l;
 105         return val_hl * 1000 / 256;
 106 }
 107
 108 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
 109 {
 110         u16 val_hl = (val_h << 8) | val_l;
 111         return val_hl * 1000 / 256;
 112 }
 113
 114 static struct lm95241_data *lm95241_update_device(struct device *dev)
 115 {
 116         struct i2c_client *client = to_i2c_client(dev);
 117         struct lm95241_data *data = i2c_get_clientdata(client);
 118
 119         mutex_lock(&data->update_lock);
 120
 121         if (time_after(jiffies, data->last_updated + data->interval) ||
 122             !data->valid) {
 123                 int i;
 124
 125                 dev_dbg(&client->dev, "Updating lm95241 data.\n");
 126                 for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
 127                         data->temp[i]
 128                           = i2c_smbus_read_byte_data(client,
 129                                                      lm95241_reg_address[i]);
 130                 data->last_updated = jiffies;
 131                 data->valid = 1;
 132         }
 133
 134         mutex_unlock(&data->update_lock);
 135
 136         return data;
 137 }
 138
 139 /* Sysfs stuff */
 140 static ssize_t show_input(struct device *dev, struct device_attribute *attr,
 141                           char *buf)
 142 {
 143         struct lm95241_data *data = lm95241_update_device(dev);
 144         int index = to_sensor_dev_attr(attr)->index;
 145
 146         return snprintf(buf, PAGE_SIZE - 1, "%d\n",
 147                         index == 0 || (data->config & (1 << (index / 2))) ?
 148                 temp_from_reg_signed(data->temp[index], data->temp[index + 1]) :
 149                 temp_from_reg_unsigned(data->temp[index],
 150                                        data->temp[index + 1]));
 151 }
 152
 153 static ssize_t show_type(struct device *dev, struct device_attribute *attr,
 154                          char *buf)
 155 {
 156         struct i2c_client *client = to_i2c_client(dev);
 157         struct lm95241_data *data = i2c_get_clientdata(client);
 158
 159         return snprintf(buf, PAGE_SIZE - 1,
 160                 data->model & to_sensor_dev_attr(attr)->index ? "1\n" : "2\n");
 161 }
 162
 163 static ssize_t set_type(struct device *dev, struct device_attribute *attr,
 164                         const char *buf, size_t count)
 165 {
 166         struct i2c_client *client = to_i2c_client(dev);
 167         struct lm95241_data *data = i2c_get_clientdata(client);
 168         unsigned long val;
 169         int shift;
 170         u8 mask = to_sensor_dev_attr(attr)->index;
 171
 172         if (kstrtoul(buf, 10, &val) < 0)
 173                 return -EINVAL;
 174         if (val != 1 && val != 2)
 175                 return -EINVAL;
 176
 177         shift = mask == R1MS_MASK ? TT1_SHIFT : TT2_SHIFT;
 178
 179         mutex_lock(&data->update_lock);
 180
 181         data->trutherm &= ~(TT_MASK << shift);
 182         if (val == 1) {
 183                 data->model |= mask;
 184                 data->trutherm |= (TT_ON << shift);
 185         } else {
 186                 data->model &= ~mask;
 187                 data->trutherm |= (TT_OFF << shift);
 188         }
 189         data->valid = 0;
 190
 191         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 192                                   data->model);
 193         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 194                                   data->trutherm);
 195
 196         mutex_unlock(&data->update_lock);
 197
 198         return count;
 199 }
 200
 201 static ssize_t show_min(struct device *dev, struct device_attribute *attr,
 202                         char *buf)
 203 {
 204         struct i2c_client *client = to_i2c_client(dev);
 205         struct lm95241_data *data = i2c_get_clientdata(client);
 206
 207         return snprintf(buf, PAGE_SIZE - 1,
 208                         data->config & to_sensor_dev_attr(attr)->index ?
 209                         "-127000\n" : "0\n");
 210 }
 211
 212 static ssize_t set_min(struct device *dev, struct device_attribute *attr,
 213                        const char *buf, size_t count)
 214 {
 215         struct i2c_client *client = to_i2c_client(dev);
 216         struct lm95241_data *data = i2c_get_clientdata(client);
 217         long val;
 218
 219         if (kstrtol(buf, 10, &val) < 0)
 220                 return -EINVAL;
 221         if (val < -128000)
 222                 return -EINVAL;
 223
 224         mutex_lock(&data->update_lock);
 225
 226         if (val < 0)
 227                 data->config |= to_sensor_dev_attr(attr)->index;
 228         else
 229                 data->config &= ~to_sensor_dev_attr(attr)->index;
 230         data->valid = 0;
 231
 232         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 233
 234         mutex_unlock(&data->update_lock);
 235
 236         return count;
 237 }
 238
 239 static ssize_t show_max(struct device *dev, struct device_attribute *attr,
 240                         char *buf)
 241 {
 242         struct i2c_client *client = to_i2c_client(dev);
 243         struct lm95241_data *data = i2c_get_clientdata(client);
 244
 245         return snprintf(buf, PAGE_SIZE - 1,
 246                         data->config & to_sensor_dev_attr(attr)->index ?
 247                         "127000\n" : "255000\n");
 248 }
 249
 250 static ssize_t set_max(struct device *dev, struct device_attribute *attr,
 251                        const char *buf, size_t count)
 252 {
 253         struct i2c_client *client = to_i2c_client(dev);
 254         struct lm95241_data *data = i2c_get_clientdata(client);
 255         long val;
 256
 257         if (kstrtol(buf, 10, &val) < 0)
 258                 return -EINVAL;
 259         if (val >= 256000)
 260                 return -EINVAL;
 261
 262         mutex_lock(&data->update_lock);
 263
 264         if (val <= 127000)
 265                 data->config |= to_sensor_dev_attr(attr)->index;
 266         else
 267                 data->config &= ~to_sensor_dev_attr(attr)->index;
 268         data->valid = 0;
 269
 270         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 271
 272         mutex_unlock(&data->update_lock);
 273
 274         return count;
 275 }
 276
 277 static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
 278                              char *buf)
 279 {
 280         struct lm95241_data *data = lm95241_update_device(dev);
 281
 282         return snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->interval
 283                         / HZ);
 284 }
 285
 286 static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
 287                             const char *buf, size_t count)
 288 {
 289         struct i2c_client *client = to_i2c_client(dev);
 290         struct lm95241_data *data = i2c_get_clientdata(client);
 291         unsigned long val;
 292
 293         if (kstrtoul(buf, 10, &val) < 0)
 294                 return -EINVAL;
 295
 296         data->interval = val * HZ / 1000;
 297
 298         return count;
 299 }
 300
 301 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
 302 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
 303 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 4);
 304 static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type,
 305                           R1MS_MASK);
 306 static SENSOR_DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type, set_type,
 307                           R2MS_MASK);
 308 static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min,
 309                           R1DF_MASK);
 310 static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min,
 311                           R2DF_MASK);
 312 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max,
 313                           R1DF_MASK);
 314 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max,
 315                           R2DF_MASK);
 316 static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
 317                    set_interval);
 318
 319 static struct attribute *lm95241_attributes[] = {
 320         &sensor_dev_attr_temp1_input.dev_attr.attr,
 321         &sensor_dev_attr_temp2_input.dev_attr.attr,
 322         &sensor_dev_attr_temp3_input.dev_attr.attr,
 323         &sensor_dev_attr_temp2_type.dev_attr.attr,
 324         &sensor_dev_attr_temp3_type.dev_attr.attr,
 325         &sensor_dev_attr_temp2_min.dev_attr.attr,
 326         &sensor_dev_attr_temp3_min.dev_attr.attr,
 327         &sensor_dev_attr_temp2_max.dev_attr.attr,
 328         &sensor_dev_attr_temp3_max.dev_attr.attr,
 329         &dev_attr_update_interval.attr,
 330         NULL
 331 };
 332
 333 static const struct attribute_group lm95241_group = {
 334         .attrs = lm95241_attributes,
 335 };
 336
 337 /* Return 0 if detection is successful, -ENODEV otherwise */
 338 static int lm95241_detect(struct i2c_client *new_client,
 339                           struct i2c_board_info *info)
 340 {
 341         struct i2c_adapter *adapter = new_client->adapter;
 342         const char *name;
 343         int mfg_id, chip_id;
 344
 345         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 346                 return -ENODEV;
 347
 348         mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
 349         if (mfg_id != NATSEMI_MAN_ID)
 350                 return -ENODEV;
 351
 352         chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
 353         switch (chip_id) {
 354         case LM95231_CHIP_ID:
 355                 name = "lm95231";
 356                 break;
 357         case LM95241_CHIP_ID:
 358                 name = "lm95241";
 359                 break;
 360         default:
 361                 return -ENODEV;
 362         }
 363
 364         /* Fill the i2c board info */
 365         strlcpy(info->type, name, I2C_NAME_SIZE);
 366         return 0;
 367 }
 368
 369 static void lm95241_init_client(struct i2c_client *client)
 370 {
 371         struct lm95241_data *data = i2c_get_clientdata(client);
 372
 373         data->interval = HZ;    /* 1 sec default */
 374         data->valid = 0;
 375         data->config = CFG_CR0076;
 376         data->model = 0;
 377         data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
 378
 379         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 380         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
 381                                   R1FE_MASK | R2FE_MASK);
 382         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 383                                   data->trutherm);
 384         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 385                                   data->model);
 386 }
 387
 388 static int lm95241_probe(struct i2c_client *new_client,
 389                          const struct i2c_device_id *id)
 390 {
 391         struct lm95241_data *data;
 392         int err;
 393
 394         data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
 395         if (!data) {
 396                 err = -ENOMEM;
 397                 goto exit;
 398         }
 399
 400         i2c_set_clientdata(new_client, data);
 401         mutex_init(&data->update_lock);
 402
 403         /* Initialize the LM95241 chip */
 404         lm95241_init_client(new_client);
 405
 406         /* Register sysfs hooks */
 407         err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group);
 408         if (err)
 409                 goto exit_free;
 410
 411         data->hwmon_dev = hwmon_device_register(&new_client->dev);
 412         if (IS_ERR(data->hwmon_dev)) {
 413                 err = PTR_ERR(data->hwmon_dev);
 414                 goto exit_remove_files;
 415         }
 416
 417         return 0;
 418
 419 exit_remove_files:
 420         sysfs_remove_group(&new_client->dev.kobj, &lm95241_group);
 421 exit_free:
 422         kfree(data);
 423 exit:
 424         return err;
 425 }
 426
 427 static int lm95241_remove(struct i2c_client *client)
 428 {
 429         struct lm95241_data *data = i2c_get_clientdata(client);
 430
 431         hwmon_device_unregister(data->hwmon_dev);
 432         sysfs_remove_group(&client->dev.kobj, &lm95241_group);
 433
 434         kfree(data);
 435         return 0;
 436 }
 437
 438 /* Driver data (common to all clients) */
 439 static const struct i2c_device_id lm95241_id[] = {
 440         { "lm95231", 0 },
 441         { "lm95241", 0 },
 442         { }
 443 };
 444 MODULE_DEVICE_TABLE(i2c, lm95241_id);
 445
 446 static struct i2c_driver lm95241_driver = {
 447         .class          = I2C_CLASS_HWMON,
 448         .driver = {
 449                 .name   = DEVNAME,
 450         },
 451         .probe          = lm95241_probe,
 452         .remove         = lm95241_remove,
 453         .id_table       = lm95241_id,
 454         .detect         = lm95241_detect,
 455         .address_list   = normal_i2c,
 456 };
 457
 458 module_i2c_driver(lm95241_driver);
 459
 460 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
 461 MODULE_DESCRIPTION("LM95241 sensor driver");
 462 MODULE_LICENSE("GPL");