drivers/hwmon/lm95245.c

   1 /*
   2  * Copyright (C) 2011 Alexander Stein <alexander.stein@systec-electronic.com>
   3  *
   4  * The LM95245 is a sensor chip made by TI / National Semiconductor.
   5  * It reports up to two temperatures (its own plus an external one).
   6  *
   7  * This driver is based on lm95241.c
   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 static const unsigned short normal_i2c[] = {
  36         0x18, 0x19, 0x29, 0x4c, 0x4d, I2C_CLIENT_END };
  37
  38 /* LM95245 registers */
  39 /* general registers */
  40 #define LM95245_REG_RW_CONFIG1          0x03
  41 #define LM95245_REG_RW_CONVERS_RATE     0x04
  42 #define LM95245_REG_W_ONE_SHOT          0x0F
  43
  44 /* diode configuration */
  45 #define LM95245_REG_RW_CONFIG2          0xBF
  46 #define LM95245_REG_RW_REMOTE_OFFH      0x11
  47 #define LM95245_REG_RW_REMOTE_OFFL      0x12
  48
  49 /* status registers */
  50 #define LM95245_REG_R_STATUS1           0x02
  51 #define LM95245_REG_R_STATUS2           0x33
  52
  53 /* limit registers */
  54 #define LM95245_REG_RW_REMOTE_OS_LIMIT          0x07
  55 #define LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT     0x20
  56 #define LM95245_REG_RW_REMOTE_TCRIT_LIMIT       0x19
  57 #define LM95245_REG_RW_COMMON_HYSTERESIS        0x21
  58
  59 /* temperature signed */
  60 #define LM95245_REG_R_LOCAL_TEMPH_S     0x00
  61 #define LM95245_REG_R_LOCAL_TEMPL_S     0x30
  62 #define LM95245_REG_R_REMOTE_TEMPH_S    0x01
  63 #define LM95245_REG_R_REMOTE_TEMPL_S    0x10
  64 /* temperature unsigned */
  65 #define LM95245_REG_R_REMOTE_TEMPH_U    0x31
  66 #define LM95245_REG_R_REMOTE_TEMPL_U    0x32
  67
  68 /* id registers */
  69 #define LM95245_REG_R_MAN_ID            0xFE
  70 #define LM95245_REG_R_CHIP_ID           0xFF
  71
  72 /* LM95245 specific bitfields */
  73 #define CFG_STOP                0x40
  74 #define CFG_REMOTE_TCRIT_MASK   0x10
  75 #define CFG_REMOTE_OS_MASK      0x08
  76 #define CFG_LOCAL_TCRIT_MASK    0x04
  77 #define CFG_LOCAL_OS_MASK       0x02
  78
  79 #define CFG2_OS_A0              0x40
  80 #define CFG2_DIODE_FAULT_OS     0x20
  81 #define CFG2_DIODE_FAULT_TCRIT  0x10
  82 #define CFG2_REMOTE_TT          0x08
  83 #define CFG2_REMOTE_FILTER_DIS  0x00
  84 #define CFG2_REMOTE_FILTER_EN   0x06
  85
  86 /* conversation rate in ms */
  87 #define RATE_CR0063     0x00
  88 #define RATE_CR0364     0x01
  89 #define RATE_CR1000     0x02
  90 #define RATE_CR2500     0x03
  91
  92 #define STATUS1_DIODE_FAULT     0x04
  93 #define STATUS1_RTCRIT          0x02
  94 #define STATUS1_LOC             0x01
  95
  96 #define MANUFACTURER_ID         0x01
  97 #define LM95235_REVISION        0xB1
  98 #define LM95245_REVISION        0xB3
  99
 100 static const u8 lm95245_reg_address[] = {
 101         LM95245_REG_R_LOCAL_TEMPH_S,
 102         LM95245_REG_R_LOCAL_TEMPL_S,
 103         LM95245_REG_R_REMOTE_TEMPH_S,
 104         LM95245_REG_R_REMOTE_TEMPL_S,
 105         LM95245_REG_R_REMOTE_TEMPH_U,
 106         LM95245_REG_R_REMOTE_TEMPL_U,
 107         LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT,
 108         LM95245_REG_RW_REMOTE_TCRIT_LIMIT,
 109         LM95245_REG_RW_COMMON_HYSTERESIS,
 110         LM95245_REG_R_STATUS1,
 111 };
 112
 113 /* Client data (each client gets its own) */
 114 struct lm95245_data {
 115         struct i2c_client *client;
 116         struct mutex update_lock;
 117         unsigned long last_updated;     /* in jiffies */
 118         unsigned long interval; /* in msecs */
 119         bool valid;             /* zero until following fields are valid */
 120         /* registers values */
 121         u8 regs[ARRAY_SIZE(lm95245_reg_address)];
 122         u8 config1, config2;
 123 };
 124
 125 /* Conversions */
 126 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
 127 {
 128         return val_h * 1000 + val_l * 1000 / 256;
 129 }
 130
 131 static int temp_from_reg_signed(u8 val_h, u8 val_l)
 132 {
 133         if (val_h & 0x80)
 134                 return (val_h - 0x100) * 1000;
 135         return temp_from_reg_unsigned(val_h, val_l);
 136 }
 137
 138 static struct lm95245_data *lm95245_update_device(struct device *dev)
 139 {
 140         struct lm95245_data *data = dev_get_drvdata(dev);
 141         struct i2c_client *client = data->client;
 142
 143         mutex_lock(&data->update_lock);
 144
 145         if (time_after(jiffies, data->last_updated
 146                 + msecs_to_jiffies(data->interval)) || !data->valid) {
 147                 int i;
 148
 149                 for (i = 0; i < ARRAY_SIZE(lm95245_reg_address); i++)
 150                         data->regs[i]
 151                           = i2c_smbus_read_byte_data(client,
 152                                                      lm95245_reg_address[i]);
 153                 data->last_updated = jiffies;
 154                 data->valid = 1;
 155         }
 156
 157         mutex_unlock(&data->update_lock);
 158
 159         return data;
 160 }
 161
 162 static unsigned long lm95245_read_conversion_rate(struct i2c_client *client)
 163 {
 164         int rate;
 165         unsigned long interval;
 166
 167         rate = i2c_smbus_read_byte_data(client, LM95245_REG_RW_CONVERS_RATE);
 168
 169         switch (rate) {
 170         case RATE_CR0063:
 171                 interval = 63;
 172                 break;
 173         case RATE_CR0364:
 174                 interval = 364;
 175                 break;
 176         case RATE_CR1000:
 177                 interval = 1000;
 178                 break;
 179         case RATE_CR2500:
 180         default:
 181                 interval = 2500;
 182                 break;
 183         }
 184
 185         return interval;
 186 }
 187
 188 static unsigned long lm95245_set_conversion_rate(struct i2c_client *client,
 189                         unsigned long interval)
 190 {
 191         int rate;
 192
 193         if (interval <= 63) {
 194                 interval = 63;
 195                 rate = RATE_CR0063;
 196         } else if (interval <= 364) {
 197                 interval = 364;
 198                 rate = RATE_CR0364;
 199         } else if (interval <= 1000) {
 200                 interval = 1000;
 201                 rate = RATE_CR1000;
 202         } else {
 203                 interval = 2500;
 204                 rate = RATE_CR2500;
 205         }
 206
 207         i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONVERS_RATE, rate);
 208
 209         return interval;
 210 }
 211
 212 /* Sysfs stuff */
 213 static ssize_t show_input(struct device *dev, struct device_attribute *attr,
 214                           char *buf)
 215 {
 216         struct lm95245_data *data = lm95245_update_device(dev);
 217         int temp;
 218         int index = to_sensor_dev_attr(attr)->index;
 219
 220         /*
 221          * Index 0 (Local temp) is always signed
 222          * Index 2 (Remote temp) has both signed and unsigned data
 223          * use signed calculation for remote if signed bit is set
 224          */
 225         if (index == 0 || data->regs[index] & 0x80)
 226                 temp = temp_from_reg_signed(data->regs[index],
 227                             data->regs[index + 1]);
 228         else
 229                 temp = temp_from_reg_unsigned(data->regs[index + 2],
 230                             data->regs[index + 3]);
 231
 232         return snprintf(buf, PAGE_SIZE - 1, "%d\n", temp);
 233 }
 234
 235 static ssize_t show_limit(struct device *dev, struct device_attribute *attr,
 236                          char *buf)
 237 {
 238         struct lm95245_data *data = lm95245_update_device(dev);
 239         int index = to_sensor_dev_attr(attr)->index;
 240
 241         return snprintf(buf, PAGE_SIZE - 1, "%d\n",
 242                         data->regs[index] * 1000);
 243 }
 244
 245 static ssize_t set_limit(struct device *dev, struct device_attribute *attr,
 246                         const char *buf, size_t count)
 247 {
 248         struct lm95245_data *data = dev_get_drvdata(dev);
 249         int index = to_sensor_dev_attr(attr)->index;
 250         struct i2c_client *client = data->client;
 251         unsigned long val;
 252
 253         if (kstrtoul(buf, 10, &val) < 0)
 254                 return -EINVAL;
 255
 256         val /= 1000;
 257
 258         val = clamp_val(val, 0, (index == 6 ? 127 : 255));
 259
 260         mutex_lock(&data->update_lock);
 261
 262         data->valid = 0;
 263
 264         i2c_smbus_write_byte_data(client, lm95245_reg_address[index], val);
 265
 266         mutex_unlock(&data->update_lock);
 267
 268         return count;
 269 }
 270
 271 static ssize_t show_crit_hyst(struct device *dev, struct device_attribute *attr,
 272                         char *buf)
 273 {
 274         struct lm95245_data *data = lm95245_update_device(dev);
 275         int index = to_sensor_dev_attr(attr)->index;
 276         int hyst = data->regs[index] - data->regs[8];
 277
 278         return snprintf(buf, PAGE_SIZE - 1, "%d\n", hyst * 1000);
 279 }
 280
 281 static ssize_t set_crit_hyst(struct device *dev, struct device_attribute *attr,
 282                         const char *buf, size_t count)
 283 {
 284         struct lm95245_data *data = dev_get_drvdata(dev);
 285         int index = to_sensor_dev_attr(attr)->index;
 286         struct i2c_client *client = data->client;
 287         unsigned long val;
 288         int hyst, limit;
 289
 290         if (kstrtoul(buf, 10, &val) < 0)
 291                 return -EINVAL;
 292
 293         mutex_lock(&data->update_lock);
 294
 295         limit = i2c_smbus_read_byte_data(client, lm95245_reg_address[index]);
 296         hyst = limit - val / 1000;
 297         hyst = clamp_val(hyst, 0, 31);
 298         data->regs[8] = hyst;
 299
 300         /* shared crit hysteresis */
 301         i2c_smbus_write_byte_data(client, LM95245_REG_RW_COMMON_HYSTERESIS,
 302                 hyst);
 303
 304         mutex_unlock(&data->update_lock);
 305
 306         return count;
 307 }
 308
 309 static ssize_t show_type(struct device *dev, struct device_attribute *attr,
 310                          char *buf)
 311 {
 312         struct lm95245_data *data = dev_get_drvdata(dev);
 313
 314         return snprintf(buf, PAGE_SIZE - 1,
 315                 data->config2 & CFG2_REMOTE_TT ? "1\n" : "2\n");
 316 }
 317
 318 static ssize_t set_type(struct device *dev, struct device_attribute *attr,
 319                         const char *buf, size_t count)
 320 {
 321         struct lm95245_data *data = dev_get_drvdata(dev);
 322         struct i2c_client *client = data->client;
 323         unsigned long val;
 324
 325         if (kstrtoul(buf, 10, &val) < 0)
 326                 return -EINVAL;
 327         if (val != 1 && val != 2)
 328                 return -EINVAL;
 329
 330         mutex_lock(&data->update_lock);
 331
 332         if (val == 1)
 333                 data->config2 |= CFG2_REMOTE_TT;
 334         else
 335                 data->config2 &= ~CFG2_REMOTE_TT;
 336
 337         data->valid = 0;
 338
 339         i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG2,
 340                                   data->config2);
 341
 342         mutex_unlock(&data->update_lock);
 343
 344         return count;
 345 }
 346
 347 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
 348                          char *buf)
 349 {
 350         struct lm95245_data *data = lm95245_update_device(dev);
 351         int index = to_sensor_dev_attr(attr)->index;
 352
 353         return snprintf(buf, PAGE_SIZE - 1, "%d\n",
 354                         !!(data->regs[9] & index));
 355 }
 356
 357 static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
 358                              char *buf)
 359 {
 360         struct lm95245_data *data = lm95245_update_device(dev);
 361
 362         return snprintf(buf, PAGE_SIZE - 1, "%lu\n", data->interval);
 363 }
 364
 365 static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
 366                             const char *buf, size_t count)
 367 {
 368         struct lm95245_data *data = dev_get_drvdata(dev);
 369         struct i2c_client *client = data->client;
 370         unsigned long val;
 371
 372         if (kstrtoul(buf, 10, &val) < 0)
 373                 return -EINVAL;
 374
 375         mutex_lock(&data->update_lock);
 376
 377         data->interval = lm95245_set_conversion_rate(client, val);
 378
 379         mutex_unlock(&data->update_lock);
 380
 381         return count;
 382 }
 383
 384 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
 385 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_limit,
 386                 set_limit, 6);
 387 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_crit_hyst,
 388                 set_crit_hyst, 6);
 389 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
 390                 STATUS1_LOC);
 391
 392 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
 393 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_limit,
 394                 set_limit, 7);
 395 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_crit_hyst, NULL, 7);
 396 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL,
 397                 STATUS1_RTCRIT);
 398 static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type,
 399                 set_type, 0);
 400 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL,
 401                 STATUS1_DIODE_FAULT);
 402
 403 static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
 404                 set_interval);
 405
 406 static struct attribute *lm95245_attrs[] = {
 407         &sensor_dev_attr_temp1_input.dev_attr.attr,
 408         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 409         &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 410         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 411         &sensor_dev_attr_temp2_input.dev_attr.attr,
 412         &sensor_dev_attr_temp2_crit.dev_attr.attr,
 413         &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
 414         &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 415         &sensor_dev_attr_temp2_type.dev_attr.attr,
 416         &sensor_dev_attr_temp2_fault.dev_attr.attr,
 417         &dev_attr_update_interval.attr,
 418         NULL
 419 };
 420 ATTRIBUTE_GROUPS(lm95245);
 421
 422 /* Return 0 if detection is successful, -ENODEV otherwise */
 423 static int lm95245_detect(struct i2c_client *new_client,
 424                           struct i2c_board_info *info)
 425 {
 426         struct i2c_adapter *adapter = new_client->adapter;
 427         int address = new_client->addr;
 428         const char *name;
 429         int rev, id;
 430
 431         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 432                 return -ENODEV;
 433
 434         id = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_MAN_ID);
 435         if (id != MANUFACTURER_ID)
 436                 return -ENODEV;
 437
 438         rev = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_CHIP_ID);
 439         switch (rev) {
 440         case LM95235_REVISION:
 441                 if (address != 0x18 && address != 0x29 && address != 0x4c)
 442                         return -ENODEV;
 443                 name = "lm95235";
 444                 break;
 445         case LM95245_REVISION:
 446                 name = "lm95245";
 447                 break;
 448         default:
 449                 return -ENODEV;
 450         }
 451
 452         strlcpy(info->type, name, I2C_NAME_SIZE);
 453         return 0;
 454 }
 455
 456 static void lm95245_init_client(struct i2c_client *client,
 457                                 struct lm95245_data *data)
 458 {
 459         data->interval = lm95245_read_conversion_rate(client);
 460
 461         data->config1 = i2c_smbus_read_byte_data(client,
 462                 LM95245_REG_RW_CONFIG1);
 463         data->config2 = i2c_smbus_read_byte_data(client,
 464                 LM95245_REG_RW_CONFIG2);
 465
 466         if (data->config1 & CFG_STOP) {
 467                 /* Clear the standby bit */
 468                 data->config1 &= ~CFG_STOP;
 469                 i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG1,
 470                         data->config1);
 471         }
 472 }
 473
 474 static int lm95245_probe(struct i2c_client *client,
 475                          const struct i2c_device_id *id)
 476 {
 477         struct device *dev = &client->dev;
 478         struct lm95245_data *data;
 479         struct device *hwmon_dev;
 480
 481         data = devm_kzalloc(dev, sizeof(struct lm95245_data), GFP_KERNEL);
 482         if (!data)
 483                 return -ENOMEM;
 484
 485         data->client = client;
 486         mutex_init(&data->update_lock);
 487
 488         /* Initialize the LM95245 chip */
 489         lm95245_init_client(client, data);
 490
 491         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 492                                                            data,
 493                                                            lm95245_groups);
 494         return PTR_ERR_OR_ZERO(hwmon_dev);
 495 }
 496
 497 /* Driver data (common to all clients) */
 498 static const struct i2c_device_id lm95245_id[] = {
 499         { "lm95235", 0 },
 500         { "lm95245", 0 },
 501         { }
 502 };
 503 MODULE_DEVICE_TABLE(i2c, lm95245_id);
 504
 505 static struct i2c_driver lm95245_driver = {
 506         .class          = I2C_CLASS_HWMON,
 507         .driver = {
 508                 .name   = "lm95245",
 509         },
 510         .probe          = lm95245_probe,
 511         .id_table       = lm95245_id,
 512         .detect         = lm95245_detect,
 513         .address_list   = normal_i2c,
 514 };
 515
 516 module_i2c_driver(lm95245_driver);
 517
 518 MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
 519 MODULE_DESCRIPTION("LM95235/LM95245 sensor driver");
 520 MODULE_LICENSE("GPL");