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
  20 #include <linux/bitops.h>
  21 #include <linux/err.h>
  22 #include <linux/i2c.h>
  23 #include <linux/init.h>
  24 #include <linux/jiffies.h>
  25 #include <linux/hwmon.h>
  26 #include <linux/module.h>
  27 #include <linux/mutex.h>
  28 #include <linux/slab.h>
  29
  30 #define DEVNAME "lm95241"
  31
  32 static const unsigned short normal_i2c[] = {
  33         0x19, 0x2a, 0x2b, I2C_CLIENT_END };
  34
  35 /* LM95241 registers */
  36 #define LM95241_REG_R_MAN_ID            0xFE
  37 #define LM95241_REG_R_CHIP_ID           0xFF
  38 #define LM95241_REG_R_STATUS            0x02
  39 #define LM95241_REG_RW_CONFIG           0x03
  40 #define LM95241_REG_RW_REM_FILTER       0x06
  41 #define LM95241_REG_RW_TRUTHERM         0x07
  42 #define LM95241_REG_W_ONE_SHOT          0x0F
  43 #define LM95241_REG_R_LOCAL_TEMPH       0x10
  44 #define LM95241_REG_R_REMOTE1_TEMPH     0x11
  45 #define LM95241_REG_R_REMOTE2_TEMPH     0x12
  46 #define LM95241_REG_R_LOCAL_TEMPL       0x20
  47 #define LM95241_REG_R_REMOTE1_TEMPL     0x21
  48 #define LM95241_REG_R_REMOTE2_TEMPL     0x22
  49 #define LM95241_REG_RW_REMOTE_MODEL     0x30
  50
  51 /* LM95241 specific bitfields */
  52 #define CFG_STOP        BIT(6)
  53 #define CFG_CR0076      0x00
  54 #define CFG_CR0182      BIT(4)
  55 #define CFG_CR1000      BIT(5)
  56 #define CFG_CR2700      (BIT(4) | BIT(5))
  57 #define CFG_CRMASK      (BIT(4) | BIT(5))
  58 #define R1MS_MASK       BIT(0)
  59 #define R2MS_MASK       BIT(2)
  60 #define R1DF_MASK       BIT(1)
  61 #define R2DF_MASK       BIT(2)
  62 #define R1FE_MASK       BIT(0)
  63 #define R2FE_MASK       BIT(2)
  64 #define R1DM            BIT(0)
  65 #define R2DM            BIT(1)
  66 #define TT1_SHIFT       0
  67 #define TT2_SHIFT       4
  68 #define TT_OFF          0
  69 #define TT_ON           1
  70 #define TT_MASK         7
  71 #define NATSEMI_MAN_ID  0x01
  72 #define LM95231_CHIP_ID 0xA1
  73 #define LM95241_CHIP_ID 0xA4
  74
  75 static const u8 lm95241_reg_address[] = {
  76         LM95241_REG_R_LOCAL_TEMPH,
  77         LM95241_REG_R_LOCAL_TEMPL,
  78         LM95241_REG_R_REMOTE1_TEMPH,
  79         LM95241_REG_R_REMOTE1_TEMPL,
  80         LM95241_REG_R_REMOTE2_TEMPH,
  81         LM95241_REG_R_REMOTE2_TEMPL
  82 };
  83
  84 /* Client data (each client gets its own) */
  85 struct lm95241_data {
  86         struct i2c_client *client;
  87         struct mutex update_lock;
  88         unsigned long last_updated;     /* in jiffies */
  89         unsigned long interval;         /* in milli-seconds */
  90         char valid;             /* zero until following fields are valid */
  91         /* registers values */
  92         u8 temp[ARRAY_SIZE(lm95241_reg_address)];
  93         u8 status, config, model, trutherm;
  94 };
  95
  96 /* Conversions */
  97 static int temp_from_reg_signed(u8 val_h, u8 val_l)
  98 {
  99         s16 val_hl = (val_h << 8) | val_l;
 100         return val_hl * 1000 / 256;
 101 }
 102
 103 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
 104 {
 105         u16 val_hl = (val_h << 8) | val_l;
 106         return val_hl * 1000 / 256;
 107 }
 108
 109 static struct lm95241_data *lm95241_update_device(struct device *dev)
 110 {
 111         struct lm95241_data *data = dev_get_drvdata(dev);
 112         struct i2c_client *client = data->client;
 113
 114         mutex_lock(&data->update_lock);
 115
 116         if (time_after(jiffies, data->last_updated
 117                        + msecs_to_jiffies(data->interval)) ||
 118             !data->valid) {
 119                 int i;
 120
 121                 dev_dbg(dev, "Updating lm95241 data.\n");
 122                 for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
 123                         data->temp[i]
 124                           = i2c_smbus_read_byte_data(client,
 125                                                      lm95241_reg_address[i]);
 126
 127                 data->status = i2c_smbus_read_byte_data(client,
 128                                                         LM95241_REG_R_STATUS);
 129                 data->last_updated = jiffies;
 130                 data->valid = 1;
 131         }
 132
 133         mutex_unlock(&data->update_lock);
 134
 135         return data;
 136 }
 137
 138 static int lm95241_read_chip(struct device *dev, u32 attr, int channel,
 139                              long *val)
 140 {
 141         struct lm95241_data *data = dev_get_drvdata(dev);
 142
 143         switch (attr) {
 144         case hwmon_chip_update_interval:
 145                 *val = data->interval;
 146                 return 0;
 147         default:
 148                 return -EOPNOTSUPP;
 149         }
 150 }
 151
 152 static int lm95241_read_temp(struct device *dev, u32 attr, int channel,
 153                              long *val)
 154 {
 155         struct lm95241_data *data = lm95241_update_device(dev);
 156
 157         switch (attr) {
 158         case hwmon_temp_input:
 159                 if (!channel || (data->config & BIT(channel - 1)))
 160                         *val = temp_from_reg_signed(data->temp[channel * 2],
 161                                                 data->temp[channel * 2 + 1]);
 162                 else
 163                         *val = temp_from_reg_unsigned(data->temp[channel * 2],
 164                                                 data->temp[channel * 2 + 1]);
 165                 return 0;
 166         case hwmon_temp_min:
 167                 if (channel == 1)
 168                         *val = (data->config & R1DF_MASK) ? -128000 : 0;
 169                 else
 170                         *val = (data->config & R2DF_MASK) ? -128000 : 0;
 171                 return 0;
 172         case hwmon_temp_max:
 173                 if (channel == 1)
 174                         *val = (data->config & R1DF_MASK) ? 127875 : 255875;
 175                 else
 176                         *val = (data->config & R2DF_MASK) ? 127875 : 255875;
 177                 return 0;
 178         case hwmon_temp_type:
 179                 if (channel == 1)
 180                         *val = (data->model & R1MS_MASK) ? 1 : 2;
 181                 else
 182                         *val = (data->model & R2MS_MASK) ? 1 : 2;
 183                 return 0;
 184         case hwmon_temp_fault:
 185                 if (channel == 1)
 186                         *val = !!(data->status & R1DM);
 187                 else
 188                         *val = !!(data->status & R2DM);
 189                 return 0;
 190         default:
 191                 return -EOPNOTSUPP;
 192         }
 193 }
 194
 195 static int lm95241_read(struct device *dev, enum hwmon_sensor_types type,
 196                         u32 attr, int channel, long *val)
 197 {
 198         switch (type) {
 199         case hwmon_chip:
 200                 return lm95241_read_chip(dev, attr, channel, val);
 201         case hwmon_temp:
 202                 return lm95241_read_temp(dev, attr, channel, val);
 203         default:
 204                 return -EOPNOTSUPP;
 205         }
 206 }
 207
 208 static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
 209                               long val)
 210 {
 211         struct lm95241_data *data = dev_get_drvdata(dev);
 212         int convrate;
 213         u8 config;
 214         int ret;
 215
 216         mutex_lock(&data->update_lock);
 217
 218         switch (attr) {
 219         case hwmon_chip_update_interval:
 220                 config = data->config & ~CFG_CRMASK;
 221                 if (val < 130) {
 222                         convrate = 76;
 223                         config |= CFG_CR0076;
 224                 } else if (val < 590) {
 225                         convrate = 182;
 226                         config |= CFG_CR0182;
 227                 } else if (val < 1850) {
 228                         convrate = 1000;
 229                         config |= CFG_CR1000;
 230                 } else {
 231                         convrate = 2700;
 232                         config |= CFG_CR2700;
 233                 }
 234                 data->interval = convrate;
 235                 data->config = config;
 236                 ret = i2c_smbus_write_byte_data(data->client,
 237                                                 LM95241_REG_RW_CONFIG, config);
 238                 break;
 239         default:
 240                 ret = -EOPNOTSUPP;
 241                 break;
 242         }
 243         mutex_unlock(&data->update_lock);
 244         return ret;
 245 }
 246
 247 static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
 248                               long val)
 249 {
 250         struct lm95241_data *data = dev_get_drvdata(dev);
 251         struct i2c_client *client = data->client;
 252         int ret;
 253
 254         mutex_lock(&data->update_lock);
 255
 256         switch (attr) {
 257         case hwmon_temp_min:
 258                 if (channel == 1) {
 259                         if (val < 0)
 260                                 data->config |= R1DF_MASK;
 261                         else
 262                                 data->config &= ~R1DF_MASK;
 263                 } else {
 264                         if (val < 0)
 265                                 data->config |= R2DF_MASK;
 266                         else
 267                                 data->config &= ~R2DF_MASK;
 268                 }
 269                 data->valid = 0;
 270                 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
 271                                                 data->config);
 272                 break;
 273         case hwmon_temp_max:
 274                 if (channel == 1) {
 275                         if (val <= 127875)
 276                                 data->config |= R1DF_MASK;
 277                         else
 278                                 data->config &= ~R1DF_MASK;
 279                 } else {
 280                         if (val <= 127875)
 281                                 data->config |= R2DF_MASK;
 282                         else
 283                                 data->config &= ~R2DF_MASK;
 284                 }
 285                 data->valid = 0;
 286                 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
 287                                                 data->config);
 288                 break;
 289         case hwmon_temp_type:
 290                 if (val != 1 && val != 2) {
 291                         ret = -EINVAL;
 292                         break;
 293                 }
 294                 if (channel == 1) {
 295                         data->trutherm &= ~(TT_MASK << TT1_SHIFT);
 296                         if (val == 1) {
 297                                 data->model |= R1MS_MASK;
 298                                 data->trutherm |= (TT_ON << TT1_SHIFT);
 299                         } else {
 300                                 data->model &= ~R1MS_MASK;
 301                                 data->trutherm |= (TT_OFF << TT1_SHIFT);
 302                         }
 303                 } else {
 304                         data->trutherm &= ~(TT_MASK << TT2_SHIFT);
 305                         if (val == 1) {
 306                                 data->model |= R2MS_MASK;
 307                                 data->trutherm |= (TT_ON << TT2_SHIFT);
 308                         } else {
 309                                 data->model &= ~R2MS_MASK;
 310                                 data->trutherm |= (TT_OFF << TT2_SHIFT);
 311                         }
 312                 }
 313                 ret = i2c_smbus_write_byte_data(client,
 314                                                 LM95241_REG_RW_REMOTE_MODEL,
 315                                                 data->model);
 316                 if (ret < 0)
 317                         break;
 318                 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 319                                                 data->trutherm);
 320                 break;
 321         default:
 322                 ret = -EOPNOTSUPP;
 323                 break;
 324         }
 325
 326         mutex_unlock(&data->update_lock);
 327
 328         return ret;
 329 }
 330
 331 static int lm95241_write(struct device *dev, enum hwmon_sensor_types type,
 332                          u32 attr, int channel, long val)
 333 {
 334         switch (type) {
 335         case hwmon_chip:
 336                 return lm95241_write_chip(dev, attr, channel, val);
 337         case hwmon_temp:
 338                 return lm95241_write_temp(dev, attr, channel, val);
 339         default:
 340                 return -EOPNOTSUPP;
 341         }
 342 }
 343
 344 static umode_t lm95241_is_visible(const void *data,
 345                                   enum hwmon_sensor_types type,
 346                                   u32 attr, int channel)
 347 {
 348         switch (type) {
 349         case hwmon_chip:
 350                 switch (attr) {
 351                 case hwmon_chip_update_interval:
 352                         return 0644;
 353                 }
 354                 break;
 355         case hwmon_temp:
 356                 switch (attr) {
 357                 case hwmon_temp_input:
 358                         return 0444;
 359                 case hwmon_temp_fault:
 360                         return 0444;
 361                 case hwmon_temp_min:
 362                 case hwmon_temp_max:
 363                 case hwmon_temp_type:
 364                         return 0644;
 365                 }
 366                 break;
 367         default:
 368                 break;
 369         }
 370         return 0;
 371 }
 372
 373 /* Return 0 if detection is successful, -ENODEV otherwise */
 374 static int lm95241_detect(struct i2c_client *new_client,
 375                           struct i2c_board_info *info)
 376 {
 377         struct i2c_adapter *adapter = new_client->adapter;
 378         const char *name;
 379         int mfg_id, chip_id;
 380
 381         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 382                 return -ENODEV;
 383
 384         mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
 385         if (mfg_id != NATSEMI_MAN_ID)
 386                 return -ENODEV;
 387
 388         chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
 389         switch (chip_id) {
 390         case LM95231_CHIP_ID:
 391                 name = "lm95231";
 392                 break;
 393         case LM95241_CHIP_ID:
 394                 name = "lm95241";
 395                 break;
 396         default:
 397                 return -ENODEV;
 398         }
 399
 400         /* Fill the i2c board info */
 401         strlcpy(info->type, name, I2C_NAME_SIZE);
 402         return 0;
 403 }
 404
 405 static void lm95241_init_client(struct i2c_client *client,
 406                                 struct lm95241_data *data)
 407 {
 408         data->interval = 1000;
 409         data->config = CFG_CR1000;
 410         data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
 411
 412         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 413         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
 414                                   R1FE_MASK | R2FE_MASK);
 415         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 416                                   data->trutherm);
 417         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 418                                   data->model);
 419 }
 420
 421 static const struct hwmon_channel_info *lm95241_info[] = {
 422         HWMON_CHANNEL_INFO(chip,
 423                            HWMON_C_UPDATE_INTERVAL),
 424         HWMON_CHANNEL_INFO(temp,
 425                            HWMON_T_INPUT,
 426                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 427                            HWMON_T_TYPE | HWMON_T_FAULT,
 428                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 429                            HWMON_T_TYPE | HWMON_T_FAULT),
 430         NULL
 431 };
 432
 433 static const struct hwmon_ops lm95241_hwmon_ops = {
 434         .is_visible = lm95241_is_visible,
 435         .read = lm95241_read,
 436         .write = lm95241_write,
 437 };
 438
 439 static const struct hwmon_chip_info lm95241_chip_info = {
 440         .ops = &lm95241_hwmon_ops,
 441         .info = lm95241_info,
 442 };
 443
 444 static int lm95241_probe(struct i2c_client *client,
 445                          const struct i2c_device_id *id)
 446 {
 447         struct device *dev = &client->dev;
 448         struct lm95241_data *data;
 449         struct device *hwmon_dev;
 450
 451         data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL);
 452         if (!data)
 453                 return -ENOMEM;
 454
 455         data->client = client;
 456         mutex_init(&data->update_lock);
 457
 458         /* Initialize the LM95241 chip */
 459         lm95241_init_client(client, data);
 460
 461         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 462                                                            data,
 463                                                            &lm95241_chip_info,
 464                                                            NULL);
 465         return PTR_ERR_OR_ZERO(hwmon_dev);
 466 }
 467
 468 /* Driver data (common to all clients) */
 469 static const struct i2c_device_id lm95241_id[] = {
 470         { "lm95231", 0 },
 471         { "lm95241", 0 },
 472         { }
 473 };
 474 MODULE_DEVICE_TABLE(i2c, lm95241_id);
 475
 476 static struct i2c_driver lm95241_driver = {
 477         .class          = I2C_CLASS_HWMON,
 478         .driver = {
 479                 .name   = DEVNAME,
 480         },
 481         .probe          = lm95241_probe,
 482         .id_table       = lm95241_id,
 483         .detect         = lm95241_detect,
 484         .address_list   = normal_i2c,
 485 };
 486
 487 module_i2c_driver(lm95241_driver);
 488
 489 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
 490 MODULE_DESCRIPTION("LM95231/LM95241 sensor driver");
 491 MODULE_LICENSE("GPL");