drivers/i2c/chips/lm90.c

   1 /*
   2  * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
   3  *          monitoring
   4  * Copyright (C) 2003-2005  Jean Delvare <khali@linux-fr.org>
   5  *
   6  * Based on the lm83 driver. The LM90 is a sensor chip made by National
   7  * Semiconductor. It reports up to two temperatures (its own plus up to
   8  * one external one) with a 0.125 deg resolution (1 deg for local
   9  * temperature) and a 3-4 deg accuracy. Complete datasheet can be
  10  * obtained from National's website at:
  11  *   http://www.national.com/pf/LM/LM90.html
  12  *
  13  * This driver also supports the LM89 and LM99, two other sensor chips
  14  * made by National Semiconductor. Both have an increased remote
  15  * temperature measurement accuracy (1 degree), and the LM99
  16  * additionally shifts remote temperatures (measured and limits) by 16
  17  * degrees, which allows for higher temperatures measurement. The
  18  * driver doesn't handle it since it can be done easily in user-space.
  19  * Complete datasheets can be obtained from National's website at:
  20  *   http://www.national.com/pf/LM/LM89.html
  21  *   http://www.national.com/pf/LM/LM99.html
  22  * Note that there is no way to differentiate between both chips.
  23  *
  24  * This driver also supports the LM86, another sensor chip made by
  25  * National Semiconductor. It is exactly similar to the LM90 except it
  26  * has a higher accuracy.
  27  * Complete datasheet can be obtained from National's website at:
  28  *   http://www.national.com/pf/LM/LM86.html
  29  *
  30  * This driver also supports the ADM1032, a sensor chip made by Analog
  31  * Devices. That chip is similar to the LM90, with a few differences
  32  * that are not handled by this driver. Complete datasheet can be
  33  * obtained from Analog's website at:
  34  *   http://products.analog.com/products/info.asp?product=ADM1032
  35  * Among others, it has a higher accuracy than the LM90, much like the
  36  * LM86 does.
  37  *
  38  * This driver also supports the MAX6657, MAX6658 and MAX6659 sensor
  39  * chips made by Maxim. These chips are similar to the LM86. Complete
  40  * datasheet can be obtained at Maxim's website at:
  41  *   http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2578
  42  * Note that there is no easy way to differentiate between the three
  43  * variants. The extra address and features of the MAX6659 are not
  44  * supported by this driver.
  45  *
  46  * This driver also supports the ADT7461 chip from Analog Devices but
  47  * only in its "compatability mode". If an ADT7461 chip is found but
  48  * is configured in non-compatible mode (where its temperature
  49  * register values are decoded differently) it is ignored by this
  50  * driver. Complete datasheet can be obtained from Analog's website
  51  * at:
  52  *   http://products.analog.com/products/info.asp?product=ADT7461
  53  *
  54  * Since the LM90 was the first chipset supported by this driver, most
  55  * comments will refer to this chipset, but are actually general and
  56  * concern all supported chipsets, unless mentioned otherwise.
  57  *
  58  * This program is free software; you can redistribute it and/or modify
  59  * it under the terms of the GNU General Public License as published by
  60  * the Free Software Foundation; either version 2 of the License, or
  61  * (at your option) any later version.
  62  *
  63  * This program is distributed in the hope that it will be useful,
  64  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  65  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  66  * GNU General Public License for more details.
  67  *
  68  * You should have received a copy of the GNU General Public License
  69  * along with this program; if not, write to the Free Software
  70  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  71  */
  72
  73 #include <linux/module.h>
  74 #include <linux/init.h>
  75 #include <linux/slab.h>
  76 #include <linux/jiffies.h>
  77 #include <linux/i2c.h>
  78 #include <linux/i2c-sensor.h>
  79 #include <linux/hwmon-sysfs.h>
  80
  81 /*
  82  * Addresses to scan
  83  * Address is fully defined internally and cannot be changed except for
  84  * MAX6659.
  85  * LM86, LM89, LM90, LM99, ADM1032, MAX6657 and MAX6658 have address 0x4c.
  86  * LM89-1, and LM99-1 have address 0x4d.
  87  * MAX6659 can have address 0x4c, 0x4d or 0x4e (unsupported).
  88  * ADT7461 always has address 0x4c.
  89  */
  90
  91 static unsigned short normal_i2c[] = { 0x4c, 0x4d, I2C_CLIENT_END };
  92 static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
  93
  94 /*
  95  * Insmod parameters
  96  */
  97
  98 SENSORS_INSMOD_6(lm90, adm1032, lm99, lm86, max6657, adt7461);
  99
 100 /*
 101  * The LM90 registers
 102  */
 103
 104 #define LM90_REG_R_MAN_ID               0xFE
 105 #define LM90_REG_R_CHIP_ID              0xFF
 106 #define LM90_REG_R_CONFIG1              0x03
 107 #define LM90_REG_W_CONFIG1              0x09
 108 #define LM90_REG_R_CONFIG2              0xBF
 109 #define LM90_REG_W_CONFIG2              0xBF
 110 #define LM90_REG_R_CONVRATE             0x04
 111 #define LM90_REG_W_CONVRATE             0x0A
 112 #define LM90_REG_R_STATUS               0x02
 113 #define LM90_REG_R_LOCAL_TEMP           0x00
 114 #define LM90_REG_R_LOCAL_HIGH           0x05
 115 #define LM90_REG_W_LOCAL_HIGH           0x0B
 116 #define LM90_REG_R_LOCAL_LOW            0x06
 117 #define LM90_REG_W_LOCAL_LOW            0x0C
 118 #define LM90_REG_R_LOCAL_CRIT           0x20
 119 #define LM90_REG_W_LOCAL_CRIT           0x20
 120 #define LM90_REG_R_REMOTE_TEMPH         0x01
 121 #define LM90_REG_R_REMOTE_TEMPL         0x10
 122 #define LM90_REG_R_REMOTE_OFFSH         0x11
 123 #define LM90_REG_W_REMOTE_OFFSH         0x11
 124 #define LM90_REG_R_REMOTE_OFFSL         0x12
 125 #define LM90_REG_W_REMOTE_OFFSL         0x12
 126 #define LM90_REG_R_REMOTE_HIGHH         0x07
 127 #define LM90_REG_W_REMOTE_HIGHH         0x0D
 128 #define LM90_REG_R_REMOTE_HIGHL         0x13
 129 #define LM90_REG_W_REMOTE_HIGHL         0x13
 130 #define LM90_REG_R_REMOTE_LOWH          0x08
 131 #define LM90_REG_W_REMOTE_LOWH          0x0E
 132 #define LM90_REG_R_REMOTE_LOWL          0x14
 133 #define LM90_REG_W_REMOTE_LOWL          0x14
 134 #define LM90_REG_R_REMOTE_CRIT          0x19
 135 #define LM90_REG_W_REMOTE_CRIT          0x19
 136 #define LM90_REG_R_TCRIT_HYST           0x21
 137 #define LM90_REG_W_TCRIT_HYST           0x21
 138
 139 /*
 140  * Conversions and various macros
 141  * For local temperatures and limits, critical limits and the hysteresis
 142  * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
 143  * For remote temperatures and limits, it uses signed 11-bit values with
 144  * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
 145  */
 146
 147 #define TEMP1_FROM_REG(val)     ((val) * 1000)
 148 #define TEMP1_TO_REG(val)       ((val) <= -128000 ? -128 : \
 149                                  (val) >= 127000 ? 127 : \
 150                                  (val) < 0 ? ((val) - 500) / 1000 : \
 151                                  ((val) + 500) / 1000)
 152 #define TEMP2_FROM_REG(val)     ((val) / 32 * 125)
 153 #define TEMP2_TO_REG(val)       ((val) <= -128000 ? 0x8000 : \
 154                                  (val) >= 127875 ? 0x7FE0 : \
 155                                  (val) < 0 ? ((val) - 62) / 125 * 32 : \
 156                                  ((val) + 62) / 125 * 32)
 157 #define HYST_TO_REG(val)        ((val) <= 0 ? 0 : (val) >= 30500 ? 31 : \
 158                                  ((val) + 500) / 1000)
 159
 160 /*
 161  * ADT7461 is almost identical to LM90 except that attempts to write
 162  * values that are outside the range 0 < temp < 127 are treated as
 163  * the boundary value.
 164  */
 165
 166 #define TEMP1_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
 167                                  (val) >= 127000 ? 127 : \
 168                                  ((val) + 500) / 1000)
 169 #define TEMP2_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
 170                                  (val) >= 127750 ? 0x7FC0 : \
 171                                  ((val) + 125) / 250 * 64)
 172
 173 /*
 174  * Functions declaration
 175  */
 176
 177 static int lm90_attach_adapter(struct i2c_adapter *adapter);
 178 static int lm90_detect(struct i2c_adapter *adapter, int address,
 179         int kind);
 180 static void lm90_init_client(struct i2c_client *client);
 181 static int lm90_detach_client(struct i2c_client *client);
 182 static struct lm90_data *lm90_update_device(struct device *dev);
 183
 184 /*
 185  * Driver data (common to all clients)
 186  */
 187
 188 static struct i2c_driver lm90_driver = {
 189         .owner          = THIS_MODULE,
 190         .name           = "lm90",
 191         .id             = I2C_DRIVERID_LM90,
 192         .flags          = I2C_DF_NOTIFY,
 193         .attach_adapter = lm90_attach_adapter,
 194         .detach_client  = lm90_detach_client,
 195 };
 196
 197 /*
 198  * Client data (each client gets its own)
 199  */
 200
 201 struct lm90_data {
 202         struct i2c_client client;
 203         struct semaphore update_lock;
 204         char valid; /* zero until following fields are valid */
 205         unsigned long last_updated; /* in jiffies */
 206         int kind;
 207
 208         /* registers values */
 209         s8 temp8[5];    /* 0: local input
 210                            1: local low limit
 211                            2: local high limit
 212                            3: local critical limit
 213                            4: remote critical limit */
 214         s16 temp11[3];  /* 0: remote input
 215                            1: remote low limit
 216                            2: remote high limit */
 217         u8 temp_hyst;
 218         u8 alarms; /* bitvector */
 219 };
 220
 221 /*
 222  * Sysfs stuff
 223  */
 224
 225 static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
 226                           char *buf)
 227 {
 228         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 229         struct lm90_data *data = lm90_update_device(dev);
 230         return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index]));
 231 }
 232
 233 static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
 234                          const char *buf, size_t count)
 235 {
 236         static const u8 reg[4] = {
 237                 LM90_REG_W_LOCAL_LOW,
 238                 LM90_REG_W_LOCAL_HIGH,
 239                 LM90_REG_W_LOCAL_CRIT,
 240                 LM90_REG_W_REMOTE_CRIT,
 241         };
 242
 243         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 244         struct i2c_client *client = to_i2c_client(dev);
 245         struct lm90_data *data = i2c_get_clientdata(client);
 246         long val = simple_strtol(buf, NULL, 10);
 247         int nr = attr->index;
 248
 249         down(&data->update_lock);
 250         if (data->kind == adt7461)
 251                 data->temp8[nr] = TEMP1_TO_REG_ADT7461(val);
 252         else
 253                 data->temp8[nr] = TEMP1_TO_REG(val);
 254         i2c_smbus_write_byte_data(client, reg[nr - 1], data->temp8[nr]);
 255         up(&data->update_lock);
 256         return count;
 257 }
 258
 259 static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
 260                            char *buf)
 261 {
 262         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 263         struct lm90_data *data = lm90_update_device(dev);
 264         return sprintf(buf, "%d\n", TEMP2_FROM_REG(data->temp11[attr->index]));
 265 }
 266
 267 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
 268                           const char *buf, size_t count)
 269 {
 270         static const u8 reg[4] = {
 271                 LM90_REG_W_REMOTE_LOWH,
 272                 LM90_REG_W_REMOTE_LOWL,
 273                 LM90_REG_W_REMOTE_HIGHH,
 274                 LM90_REG_W_REMOTE_HIGHL,
 275         };
 276
 277         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 278         struct i2c_client *client = to_i2c_client(dev);
 279         struct lm90_data *data = i2c_get_clientdata(client);
 280         long val = simple_strtol(buf, NULL, 10);
 281         int nr = attr->index;
 282
 283         down(&data->update_lock);
 284         if (data->kind == adt7461)
 285                 data->temp11[nr] = TEMP2_TO_REG_ADT7461(val);
 286         else
 287                 data->temp11[nr] = TEMP2_TO_REG(val);
 288         i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
 289                                   data->temp11[nr] >> 8);
 290         i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
 291                                   data->temp11[nr] & 0xff);
 292         up(&data->update_lock);
 293         return count;
 294 }
 295
 296 static ssize_t show_temphyst(struct device *dev, struct device_attribute *devattr,
 297                              char *buf)
 298 {
 299         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 300         struct lm90_data *data = lm90_update_device(dev);
 301         return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index])
 302                        - TEMP1_FROM_REG(data->temp_hyst));
 303 }
 304
 305 static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
 306                             const char *buf, size_t count)
 307 {
 308         struct i2c_client *client = to_i2c_client(dev);
 309         struct lm90_data *data = i2c_get_clientdata(client);
 310         long val = simple_strtol(buf, NULL, 10);
 311         long hyst;
 312
 313         down(&data->update_lock);
 314         hyst = TEMP1_FROM_REG(data->temp8[3]) - val;
 315         i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
 316                                   HYST_TO_REG(hyst));
 317         up(&data->update_lock);
 318         return count;
 319 }
 320
 321 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
 322                            char *buf)
 323 {
 324         struct lm90_data *data = lm90_update_device(dev);
 325         return sprintf(buf, "%d\n", data->alarms);
 326 }
 327
 328 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp8, NULL, 0);
 329 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
 330 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
 331         set_temp8, 1);
 332 static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
 333         set_temp11, 1);
 334 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
 335         set_temp8, 2);
 336 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
 337         set_temp11, 2);
 338 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
 339         set_temp8, 3);
 340 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
 341         set_temp8, 4);
 342 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
 343         set_temphyst, 3);
 344 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 4);
 345 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 346
 347 /*
 348  * Real code
 349  */
 350
 351 static int lm90_attach_adapter(struct i2c_adapter *adapter)
 352 {
 353         if (!(adapter->class & I2C_CLASS_HWMON))
 354                 return 0;
 355         return i2c_detect(adapter, &addr_data, lm90_detect);
 356 }
 357
 358 /*
 359  * The following function does more than just detection. If detection
 360  * succeeds, it also registers the new chip.
 361  */
 362 static int lm90_detect(struct i2c_adapter *adapter, int address, int kind)
 363 {
 364         struct i2c_client *new_client;
 365         struct lm90_data *data;
 366         int err = 0;
 367         const char *name = "";
 368
 369         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 370                 goto exit;
 371
 372         if (!(data = kmalloc(sizeof(struct lm90_data), GFP_KERNEL))) {
 373                 err = -ENOMEM;
 374                 goto exit;
 375         }
 376         memset(data, 0, sizeof(struct lm90_data));
 377
 378         /* The common I2C client data is placed right before the
 379            LM90-specific data. */
 380         new_client = &data->client;
 381         i2c_set_clientdata(new_client, data);
 382         new_client->addr = address;
 383         new_client->adapter = adapter;
 384         new_client->driver = &lm90_driver;
 385         new_client->flags = 0;
 386
 387         /*
 388          * Now we do the remaining detection. A negative kind means that
 389          * the driver was loaded with no force parameter (default), so we
 390          * must both detect and identify the chip. A zero kind means that
 391          * the driver was loaded with the force parameter, the detection
 392          * step shall be skipped. A positive kind means that the driver
 393          * was loaded with the force parameter and a given kind of chip is
 394          * requested, so both the detection and the identification steps
 395          * are skipped.
 396          */
 397
 398         /* Default to an LM90 if forced */
 399         if (kind == 0)
 400                 kind = lm90;
 401
 402         if (kind < 0) { /* detection and identification */
 403                 u8 man_id, chip_id, reg_config1, reg_convrate;
 404
 405                 man_id = i2c_smbus_read_byte_data(new_client,
 406                          LM90_REG_R_MAN_ID);
 407                 chip_id = i2c_smbus_read_byte_data(new_client,
 408                           LM90_REG_R_CHIP_ID);
 409                 reg_config1 = i2c_smbus_read_byte_data(new_client,
 410                               LM90_REG_R_CONFIG1);
 411                 reg_convrate = i2c_smbus_read_byte_data(new_client,
 412                                LM90_REG_R_CONVRATE);
 413
 414                 if (man_id == 0x01) { /* National Semiconductor */
 415                         u8 reg_config2;
 416
 417                         reg_config2 = i2c_smbus_read_byte_data(new_client,
 418                                       LM90_REG_R_CONFIG2);
 419
 420                         if ((reg_config1 & 0x2A) == 0x00
 421                          && (reg_config2 & 0xF8) == 0x00
 422                          && reg_convrate <= 0x09) {
 423                                 if (address == 0x4C
 424                                  && (chip_id & 0xF0) == 0x20) { /* LM90 */
 425                                         kind = lm90;
 426                                 } else
 427                                 if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
 428                                         kind = lm99;
 429                                 } else
 430                                 if (address == 0x4C
 431                                  && (chip_id & 0xF0) == 0x10) { /* LM86 */
 432                                         kind = lm86;
 433                                 }
 434                         }
 435                 } else
 436                 if (man_id == 0x41) { /* Analog Devices */
 437                         if (address == 0x4C
 438                          && (chip_id & 0xF0) == 0x40 /* ADM1032 */
 439                          && (reg_config1 & 0x3F) == 0x00
 440                          && reg_convrate <= 0x0A) {
 441                                 kind = adm1032;
 442                         } else
 443                         if (address == 0x4c
 444                          && chip_id == 0x51 /* ADT7461 */
 445                          && (reg_config1 & 0x1F) == 0x00 /* check compat mode */
 446                          && reg_convrate <= 0x0A) {
 447                                 kind = adt7461;
 448                         }
 449                 } else
 450                 if (man_id == 0x4D) { /* Maxim */
 451                         /*
 452                          * The Maxim variants do NOT have a chip_id register.
 453                          * Reading from that address will return the last read
 454                          * value, which in our case is those of the man_id
 455                          * register. Likewise, the config1 register seems to
 456                          * lack a low nibble, so the value will be those of the
 457                          * previous read, so in our case those of the man_id
 458                          * register.
 459                          */
 460                         if (chip_id == man_id
 461                          && (reg_config1 & 0x1F) == (man_id & 0x0F)
 462                          && reg_convrate <= 0x09) {
 463                                 kind = max6657;
 464                         }
 465                 }
 466
 467                 if (kind <= 0) { /* identification failed */
 468                         dev_info(&adapter->dev,
 469                             "Unsupported chip (man_id=0x%02X, "
 470                             "chip_id=0x%02X).\n", man_id, chip_id);
 471                         goto exit_free;
 472                 }
 473         }
 474
 475         if (kind == lm90) {
 476                 name = "lm90";
 477         } else if (kind == adm1032) {
 478                 name = "adm1032";
 479         } else if (kind == lm99) {
 480                 name = "lm99";
 481         } else if (kind == lm86) {
 482                 name = "lm86";
 483         } else if (kind == max6657) {
 484                 name = "max6657";
 485         } else if (kind == adt7461) {
 486                 name = "adt7461";
 487         }
 488
 489         /* We can fill in the remaining client fields */
 490         strlcpy(new_client->name, name, I2C_NAME_SIZE);
 491         data->valid = 0;
 492         data->kind = kind;
 493         init_MUTEX(&data->update_lock);
 494
 495         /* Tell the I2C layer a new client has arrived */
 496         if ((err = i2c_attach_client(new_client)))
 497                 goto exit_free;
 498
 499         /* Initialize the LM90 chip */
 500         lm90_init_client(new_client);
 501
 502         /* Register sysfs hooks */
 503         device_create_file(&new_client->dev,
 504                            &sensor_dev_attr_temp1_input.dev_attr);
 505         device_create_file(&new_client->dev,
 506                            &sensor_dev_attr_temp2_input.dev_attr);
 507         device_create_file(&new_client->dev,
 508                            &sensor_dev_attr_temp1_min.dev_attr);
 509         device_create_file(&new_client->dev,
 510                            &sensor_dev_attr_temp2_min.dev_attr);
 511         device_create_file(&new_client->dev,
 512                            &sensor_dev_attr_temp1_max.dev_attr);
 513         device_create_file(&new_client->dev,
 514                            &sensor_dev_attr_temp2_max.dev_attr);
 515         device_create_file(&new_client->dev,
 516                            &sensor_dev_attr_temp1_crit.dev_attr);
 517         device_create_file(&new_client->dev,
 518                            &sensor_dev_attr_temp2_crit.dev_attr);
 519         device_create_file(&new_client->dev,
 520                            &sensor_dev_attr_temp1_crit_hyst.dev_attr);
 521         device_create_file(&new_client->dev,
 522                            &sensor_dev_attr_temp2_crit_hyst.dev_attr);
 523         device_create_file(&new_client->dev, &dev_attr_alarms);
 524
 525         return 0;
 526
 527 exit_free:
 528         kfree(data);
 529 exit:
 530         return err;
 531 }
 532
 533 static void lm90_init_client(struct i2c_client *client)
 534 {
 535         u8 config;
 536
 537         /*
 538          * Start the conversions.
 539          */
 540         i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
 541                                   5); /* 2 Hz */
 542         config = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG1);
 543         if (config & 0x40)
 544                 i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
 545                                           config & 0xBF); /* run */
 546 }
 547
 548 static int lm90_detach_client(struct i2c_client *client)
 549 {
 550         int err;
 551
 552         if ((err = i2c_detach_client(client))) {
 553                 dev_err(&client->dev, "Client deregistration failed, "
 554                         "client not detached.\n");
 555                 return err;
 556         }
 557
 558         kfree(i2c_get_clientdata(client));
 559         return 0;
 560 }
 561
 562 static struct lm90_data *lm90_update_device(struct device *dev)
 563 {
 564         struct i2c_client *client = to_i2c_client(dev);
 565         struct lm90_data *data = i2c_get_clientdata(client);
 566
 567         down(&data->update_lock);
 568
 569         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 570                 u8 oldh, newh;
 571
 572                 dev_dbg(&client->dev, "Updating lm90 data.\n");
 573                 data->temp8[0] = i2c_smbus_read_byte_data(client,
 574                                  LM90_REG_R_LOCAL_TEMP);
 575                 data->temp8[1] = i2c_smbus_read_byte_data(client,
 576                                  LM90_REG_R_LOCAL_LOW);
 577                 data->temp8[2] = i2c_smbus_read_byte_data(client,
 578                                  LM90_REG_R_LOCAL_HIGH);
 579                 data->temp8[3] = i2c_smbus_read_byte_data(client,
 580                                  LM90_REG_R_LOCAL_CRIT);
 581                 data->temp8[4] = i2c_smbus_read_byte_data(client,
 582                                  LM90_REG_R_REMOTE_CRIT);
 583                 data->temp_hyst = i2c_smbus_read_byte_data(client,
 584                                   LM90_REG_R_TCRIT_HYST);
 585
 586                 /*
 587                  * There is a trick here. We have to read two registers to
 588                  * have the remote sensor temperature, but we have to beware
 589                  * a conversion could occur inbetween the readings. The
 590                  * datasheet says we should either use the one-shot
 591                  * conversion register, which we don't want to do (disables
 592                  * hardware monitoring) or monitor the busy bit, which is
 593                  * impossible (we can't read the values and monitor that bit
 594                  * at the exact same time). So the solution used here is to
 595                  * read the high byte once, then the low byte, then the high
 596                  * byte again. If the new high byte matches the old one,
 597                  * then we have a valid reading. Else we have to read the low
 598                  * byte again, and now we believe we have a correct reading.
 599                  */
 600                 oldh = i2c_smbus_read_byte_data(client,
 601                        LM90_REG_R_REMOTE_TEMPH);
 602                 data->temp11[0] = i2c_smbus_read_byte_data(client,
 603                                   LM90_REG_R_REMOTE_TEMPL);
 604                 newh = i2c_smbus_read_byte_data(client,
 605                        LM90_REG_R_REMOTE_TEMPH);
 606                 if (newh != oldh) {
 607                         data->temp11[0] = i2c_smbus_read_byte_data(client,
 608                                           LM90_REG_R_REMOTE_TEMPL);
 609 #ifdef DEBUG
 610                         oldh = i2c_smbus_read_byte_data(client,
 611                                LM90_REG_R_REMOTE_TEMPH);
 612                         /* oldh is actually newer */
 613                         if (newh != oldh)
 614                                 dev_warn(&client->dev, "Remote temperature may be "
 615                                          "wrong.\n");
 616 #endif
 617                 }
 618                 data->temp11[0] |= (newh << 8);
 619
 620                 data->temp11[1] = (i2c_smbus_read_byte_data(client,
 621                                    LM90_REG_R_REMOTE_LOWH) << 8) +
 622                                    i2c_smbus_read_byte_data(client,
 623                                    LM90_REG_R_REMOTE_LOWL);
 624                 data->temp11[2] = (i2c_smbus_read_byte_data(client,
 625                                    LM90_REG_R_REMOTE_HIGHH) << 8) +
 626                                    i2c_smbus_read_byte_data(client,
 627                                    LM90_REG_R_REMOTE_HIGHL);
 628                 data->alarms = i2c_smbus_read_byte_data(client,
 629                                LM90_REG_R_STATUS);
 630
 631                 data->last_updated = jiffies;
 632                 data->valid = 1;
 633         }
 634
 635         up(&data->update_lock);
 636
 637         return data;
 638 }
 639
 640 static int __init sensors_lm90_init(void)
 641 {
 642         return i2c_add_driver(&lm90_driver);
 643 }
 644
 645 static void __exit sensors_lm90_exit(void)
 646 {
 647         i2c_del_driver(&lm90_driver);
 648 }
 649
 650 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 651 MODULE_DESCRIPTION("LM90/ADM1032 driver");
 652 MODULE_LICENSE("GPL");
 653
 654 module_init(sensors_lm90_init);
 655 module_exit(sensors_lm90_exit);