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 CFG_CRMASK 0x30
  63 #define R1MS_SHIFT 0
  64 #define R2MS_SHIFT 2
  65 #define R1MS_MASK (0x01 << (R1MS_SHIFT))
  66 #define R2MS_MASK (0x01 << (R2MS_SHIFT))
  67 #define R1DF_SHIFT 1
  68 #define R2DF_SHIFT 2
  69 #define R1DF_MASK (0x01 << (R1DF_SHIFT))
  70 #define R2DF_MASK (0x01 << (R2DF_SHIFT))
  71 #define R1FE_MASK 0x01
  72 #define R2FE_MASK 0x05
  73 #define TT1_SHIFT 0
  74 #define TT2_SHIFT 4
  75 #define TT_OFF 0
  76 #define TT_ON 1
  77 #define TT_MASK 7
  78 #define NATSEMI_MAN_ID  0x01
  79 #define LM95231_CHIP_ID 0xA1
  80 #define LM95241_CHIP_ID 0xA4
  81
  82 static const u8 lm95241_reg_address[] = {
  83         LM95241_REG_R_LOCAL_TEMPH,
  84         LM95241_REG_R_LOCAL_TEMPL,
  85         LM95241_REG_R_REMOTE1_TEMPH,
  86         LM95241_REG_R_REMOTE1_TEMPL,
  87         LM95241_REG_R_REMOTE2_TEMPH,
  88         LM95241_REG_R_REMOTE2_TEMPL
  89 };
  90
  91 /* Client data (each client gets its own) */
  92 struct lm95241_data {
  93         struct i2c_client *client;
  94         struct mutex update_lock;
  95         unsigned long last_updated;     /* in jiffies */
  96         unsigned long interval;         /* in milli-seconds */
  97         char valid;             /* zero until following fields are valid */
  98         /* registers values */
  99         u8 temp[ARRAY_SIZE(lm95241_reg_address)];
 100         u8 config, model, trutherm;
 101 };
 102
 103 /* Conversions */
 104 static int temp_from_reg_signed(u8 val_h, u8 val_l)
 105 {
 106         s16 val_hl = (val_h << 8) | val_l;
 107         return val_hl * 1000 / 256;
 108 }
 109
 110 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
 111 {
 112         u16 val_hl = (val_h << 8) | val_l;
 113         return val_hl * 1000 / 256;
 114 }
 115
 116 static struct lm95241_data *lm95241_update_device(struct device *dev)
 117 {
 118         struct lm95241_data *data = dev_get_drvdata(dev);
 119         struct i2c_client *client = data->client;
 120
 121         mutex_lock(&data->update_lock);
 122
 123         if (time_after(jiffies, data->last_updated
 124                        + msecs_to_jiffies(data->interval)) ||
 125             !data->valid) {
 126                 int i;
 127
 128                 dev_dbg(dev, "Updating lm95241 data.\n");
 129                 for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
 130                         data->temp[i]
 131                           = i2c_smbus_read_byte_data(client,
 132                                                      lm95241_reg_address[i]);
 133                 data->last_updated = jiffies;
 134                 data->valid = 1;
 135         }
 136
 137         mutex_unlock(&data->update_lock);
 138
 139         return data;
 140 }
 141
 142 /* Sysfs stuff */
 143 static ssize_t show_input(struct device *dev, struct device_attribute *attr,
 144                           char *buf)
 145 {
 146         struct lm95241_data *data = lm95241_update_device(dev);
 147         int index = to_sensor_dev_attr(attr)->index;
 148
 149         return snprintf(buf, PAGE_SIZE - 1, "%d\n",
 150                         index == 0 || (data->config & (1 << (index / 2))) ?
 151                 temp_from_reg_signed(data->temp[index], data->temp[index + 1]) :
 152                 temp_from_reg_unsigned(data->temp[index],
 153                                        data->temp[index + 1]));
 154 }
 155
 156 static ssize_t show_type(struct device *dev, struct device_attribute *attr,
 157                          char *buf)
 158 {
 159         struct lm95241_data *data = dev_get_drvdata(dev);
 160
 161         return snprintf(buf, PAGE_SIZE - 1,
 162                 data->model & to_sensor_dev_attr(attr)->index ? "1\n" : "2\n");
 163 }
 164
 165 static ssize_t set_type(struct device *dev, struct device_attribute *attr,
 166                         const char *buf, size_t count)
 167 {
 168         struct lm95241_data *data = dev_get_drvdata(dev);
 169         struct i2c_client *client = data->client;
 170         unsigned long val;
 171         int shift;
 172         u8 mask = to_sensor_dev_attr(attr)->index;
 173
 174         if (kstrtoul(buf, 10, &val) < 0)
 175                 return -EINVAL;
 176         if (val != 1 && val != 2)
 177                 return -EINVAL;
 178
 179         shift = mask == R1MS_MASK ? TT1_SHIFT : TT2_SHIFT;
 180
 181         mutex_lock(&data->update_lock);
 182
 183         data->trutherm &= ~(TT_MASK << shift);
 184         if (val == 1) {
 185                 data->model |= mask;
 186                 data->trutherm |= (TT_ON << shift);
 187         } else {
 188                 data->model &= ~mask;
 189                 data->trutherm |= (TT_OFF << shift);
 190         }
 191         data->valid = 0;
 192
 193         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 194                                   data->model);
 195         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 196                                   data->trutherm);
 197
 198         mutex_unlock(&data->update_lock);
 199
 200         return count;
 201 }
 202
 203 static ssize_t show_min(struct device *dev, struct device_attribute *attr,
 204                         char *buf)
 205 {
 206         struct lm95241_data *data = dev_get_drvdata(dev);
 207
 208         return snprintf(buf, PAGE_SIZE - 1,
 209                         data->config & to_sensor_dev_attr(attr)->index ?
 210                         "-127000\n" : "0\n");
 211 }
 212
 213 static ssize_t set_min(struct device *dev, struct device_attribute *attr,
 214                        const char *buf, size_t count)
 215 {
 216         struct lm95241_data *data = dev_get_drvdata(dev);
 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(data->client, LM95241_REG_RW_CONFIG,
 233                                   data->config);
 234
 235         mutex_unlock(&data->update_lock);
 236
 237         return count;
 238 }
 239
 240 static ssize_t show_max(struct device *dev, struct device_attribute *attr,
 241                         char *buf)
 242 {
 243         struct lm95241_data *data = dev_get_drvdata(dev);
 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 lm95241_data *data = dev_get_drvdata(dev);
 254         long val;
 255
 256         if (kstrtol(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(data->client, LM95241_REG_RW_CONFIG,
 270                                   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", data->interval);
 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 lm95241_data *data = dev_get_drvdata(dev);
 289         unsigned long val;
 290         int convrate;
 291         u8 config;
 292
 293         if (kstrtoul(buf, 10, &val) < 0)
 294                 return -EINVAL;
 295
 296         mutex_lock(&data->update_lock);
 297
 298         config = data->config & ~CFG_CRMASK;
 299
 300         if (val < 130) {
 301                 convrate = 76;
 302                 config |= CFG_CR0076;
 303         } else if (val < 590) {
 304                 convrate = 182;
 305                 config |= CFG_CR0182;
 306         } else if (val < 1850) {
 307                 convrate = 1000;
 308                 config |= CFG_CR1000;
 309         } else {
 310                 convrate = 2700;
 311                 config |= CFG_CR2700;
 312         }
 313
 314         data->interval = convrate;
 315         data->config = config;
 316         i2c_smbus_write_byte_data(data->client, LM95241_REG_RW_CONFIG,
 317                                   config);
 318         mutex_unlock(&data->update_lock);
 319
 320         return count;
 321 }
 322
 323 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
 324 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
 325 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 4);
 326 static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type,
 327                           R1MS_MASK);
 328 static SENSOR_DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type, set_type,
 329                           R2MS_MASK);
 330 static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min,
 331                           R1DF_MASK);
 332 static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min,
 333                           R2DF_MASK);
 334 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max,
 335                           R1DF_MASK);
 336 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max,
 337                           R2DF_MASK);
 338 static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
 339                    set_interval);
 340
 341 static struct attribute *lm95241_attrs[] = {
 342         &sensor_dev_attr_temp1_input.dev_attr.attr,
 343         &sensor_dev_attr_temp2_input.dev_attr.attr,
 344         &sensor_dev_attr_temp3_input.dev_attr.attr,
 345         &sensor_dev_attr_temp2_type.dev_attr.attr,
 346         &sensor_dev_attr_temp3_type.dev_attr.attr,
 347         &sensor_dev_attr_temp2_min.dev_attr.attr,
 348         &sensor_dev_attr_temp3_min.dev_attr.attr,
 349         &sensor_dev_attr_temp2_max.dev_attr.attr,
 350         &sensor_dev_attr_temp3_max.dev_attr.attr,
 351         &dev_attr_update_interval.attr,
 352         NULL
 353 };
 354 ATTRIBUTE_GROUPS(lm95241);
 355
 356 /* Return 0 if detection is successful, -ENODEV otherwise */
 357 static int lm95241_detect(struct i2c_client *new_client,
 358                           struct i2c_board_info *info)
 359 {
 360         struct i2c_adapter *adapter = new_client->adapter;
 361         const char *name;
 362         int mfg_id, chip_id;
 363
 364         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 365                 return -ENODEV;
 366
 367         mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
 368         if (mfg_id != NATSEMI_MAN_ID)
 369                 return -ENODEV;
 370
 371         chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
 372         switch (chip_id) {
 373         case LM95231_CHIP_ID:
 374                 name = "lm95231";
 375                 break;
 376         case LM95241_CHIP_ID:
 377                 name = "lm95241";
 378                 break;
 379         default:
 380                 return -ENODEV;
 381         }
 382
 383         /* Fill the i2c board info */
 384         strlcpy(info->type, name, I2C_NAME_SIZE);
 385         return 0;
 386 }
 387
 388 static void lm95241_init_client(struct i2c_client *client,
 389                                 struct lm95241_data *data)
 390 {
 391         data->interval = 1000;
 392         data->config = CFG_CR1000;
 393         data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
 394
 395         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 396         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
 397                                   R1FE_MASK | R2FE_MASK);
 398         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 399                                   data->trutherm);
 400         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 401                                   data->model);
 402 }
 403
 404 static int lm95241_probe(struct i2c_client *client,
 405                          const struct i2c_device_id *id)
 406 {
 407         struct device *dev = &client->dev;
 408         struct lm95241_data *data;
 409         struct device *hwmon_dev;
 410
 411         data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL);
 412         if (!data)
 413                 return -ENOMEM;
 414
 415         data->client = client;
 416         mutex_init(&data->update_lock);
 417
 418         /* Initialize the LM95241 chip */
 419         lm95241_init_client(client, data);
 420
 421         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 422                                                            data,
 423                                                            lm95241_groups);
 424         return PTR_ERR_OR_ZERO(hwmon_dev);
 425 }
 426
 427 /* Driver data (common to all clients) */
 428 static const struct i2c_device_id lm95241_id[] = {
 429         { "lm95231", 0 },
 430         { "lm95241", 0 },
 431         { }
 432 };
 433 MODULE_DEVICE_TABLE(i2c, lm95241_id);
 434
 435 static struct i2c_driver lm95241_driver = {
 436         .class          = I2C_CLASS_HWMON,
 437         .driver = {
 438                 .name   = DEVNAME,
 439         },
 440         .probe          = lm95241_probe,
 441         .id_table       = lm95241_id,
 442         .detect         = lm95241_detect,
 443         .address_list   = normal_i2c,
 444 };
 445
 446 module_i2c_driver(lm95241_driver);
 447
 448 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
 449 MODULE_DESCRIPTION("LM95241 sensor driver");
 450 MODULE_LICENSE("GPL");