drivers/w1/slaves/w1_therm.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      w1_therm.c
   4  *
   5  * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
   6  */
   7
   8 #include <asm/types.h>
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/moduleparam.h>
  13 #include <linux/sched.h>
  14 #include <linux/device.h>
  15 #include <linux/types.h>
  16 #include <linux/slab.h>
  17 #include <linux/delay.h>
  18 #include <linux/hwmon.h>
  19 #include <linux/string.h>
  20 #include <linux/jiffies.h>
  21
  22 #include <linux/w1.h>
  23
  24 #define W1_THERM_DS18S20        0x10
  25 #define W1_THERM_DS1822         0x22
  26 #define W1_THERM_DS18B20        0x28
  27 #define W1_THERM_DS1825         0x3B
  28 #define W1_THERM_DS28EA00       0x42
  29
  30 /*
  31  * Allow the strong pullup to be disabled, but default to enabled.
  32  * If it was disabled a parasite powered device might not get the require
  33  * current to do a temperature conversion.  If it is enabled parasite powered
  34  * devices have a better chance of getting the current required.
  35  * In case the parasite power-detection is not working (seems to be the case
  36  * for some DS18S20) the strong pullup can also be forced, regardless of the
  37  * power state of the devices.
  38  *
  39  * Summary of options:
  40  * - strong_pullup = 0  Disable strong pullup completely
  41  * - strong_pullup = 1  Enable automatic strong pullup detection
  42  * - strong_pullup = 2  Force strong pullup
  43  */
  44 static int w1_strong_pullup = 1;
  45 module_param_named(strong_pullup, w1_strong_pullup, int, 0);
  46
  47 /* Counter for devices supporting bulk reading */
  48 static u16 bulk_read_device_counter; /* =0 as per C standard */
  49
  50 /* This command should be in public header w1.h but is not */
  51 #define W1_RECALL_EEPROM        0xB8
  52
  53 /* Nb of try for an operation */
  54 #define W1_THERM_MAX_TRY                5
  55
  56 /* ms delay to retry bus mutex */
  57 #define W1_THERM_RETRY_DELAY            20
  58
  59 /* delay in ms to write in EEPROM */
  60 #define W1_THERM_EEPROM_WRITE_DELAY     10
  61
  62 #define EEPROM_CMD_WRITE    "save"      /* cmd for write eeprom sysfs */
  63 #define EEPROM_CMD_READ     "restore"   /* cmd for read eeprom sysfs */
  64 #define BULK_TRIGGER_CMD    "trigger"   /* cmd to trigger a bulk read */
  65
  66 #define MIN_TEMP        -55     /* min temperature that can be measured */
  67 #define MAX_TEMP        125     /* max temperature that can be measured */
  68
  69 /* Allowed values for sysfs conv_time attribute */
  70 #define CONV_TIME_DEFAULT 0
  71 #define CONV_TIME_MEASURE 1
  72
  73 /* Bits in sysfs "features" value */
  74 #define W1_THERM_CHECK_RESULT 1 /* Enable conversion success check */
  75 #define W1_THERM_POLL_COMPLETION 2      /* Poll for conversion completion */
  76 #define W1_THERM_FEATURES_MASK 3                /* All values mask */
  77
  78 /* Poll period in milliseconds. Should be less then a shortest operation on the device */
  79 #define W1_POLL_PERIOD 32
  80 #define W1_POLL_CONVERT_TEMP 2000       /* Timeout for W1_CONVERT_TEMP, ms */
  81 #define W1_POLL_RECALL_EEPROM 500       /* Timeout for W1_RECALL_EEPROM, ms*/
  82
  83 /* Masks for resolution functions, work with all devices */
  84 /* Bit mask for config register for all devices, bits 7,6,5 */
  85 #define W1_THERM_RESOLUTION_MASK 0xE0
  86 /* Bit offset of resolution in config register for all devices */
  87 #define W1_THERM_RESOLUTION_SHIFT 5
  88 /* Bit offset of resolution in config register for all devices */
  89 #define W1_THERM_RESOLUTION_SHIFT 5
  90 /* Add this to bit value to get resolution */
  91 #define W1_THERM_RESOLUTION_MIN 9
  92 /* Maximum allowed value */
  93 #define W1_THERM_RESOLUTION_MAX 14
  94
  95 /* Helpers Macros */
  96
  97 /*
  98  * return a pointer on the slave w1_therm_family_converter struct:
  99  * always test family data existence before using this macro
 100  */
 101 #define SLAVE_SPECIFIC_FUNC(sl) \
 102         (((struct w1_therm_family_data *)(sl->family_data))->specific_functions)
 103
 104 /*
 105  * return the power mode of the sl slave : 1-ext, 0-parasite, <0 unknown
 106  * always test family data existence before using this macro
 107  */
 108 #define SLAVE_POWERMODE(sl) \
 109         (((struct w1_therm_family_data *)(sl->family_data))->external_powered)
 110
 111 /*
 112  * return the resolution in bit of the sl slave : <0 unknown
 113  * always test family data existence before using this macro
 114  */
 115 #define SLAVE_RESOLUTION(sl) \
 116         (((struct w1_therm_family_data *)(sl->family_data))->resolution)
 117
 118 /*
 119  * return the conv_time_override of the sl slave
 120  * always test family data existence before using this macro
 121  */
 122  #define SLAVE_CONV_TIME_OVERRIDE(sl) \
 123         (((struct w1_therm_family_data *)(sl->family_data))->conv_time_override)
 124
 125 /*
 126  * return the features of the sl slave
 127  * always test family data existence before using this macro
 128  */
 129  #define SLAVE_FEATURES(sl) \
 130         (((struct w1_therm_family_data *)(sl->family_data))->features)
 131
 132 /*
 133  * return whether or not a converT command has been issued to the slave
 134  * * 0: no bulk read is pending
 135  * * -1: conversion is in progress
 136  * * 1: conversion done, result to be read
 137  */
 138 #define SLAVE_CONVERT_TRIGGERED(sl) \
 139         (((struct w1_therm_family_data *)(sl->family_data))->convert_triggered)
 140
 141 /* return the address of the refcnt in the family data */
 142 #define THERM_REFCNT(family_data) \
 143         (&((struct w1_therm_family_data *)family_data)->refcnt)
 144
 145 /* Structs definition */
 146
 147 /**
 148  * struct w1_therm_family_converter - bind device specific functions
 149  * @broken: flag for non-registred families
 150  * @reserved: not used here
 151  * @f: pointer to the device binding structure
 152  * @convert: pointer to the device conversion function
 153  * @get_conversion_time: pointer to the device conversion time function
 154  * @set_resolution: pointer to the device set_resolution function
 155  * @get_resolution: pointer to the device get_resolution function
 156  * @write_data: pointer to the device writing function (2 or 3 bytes)
 157  * @bulk_read: true if device family support bulk read, false otherwise
 158  */
 159 struct w1_therm_family_converter {
 160         u8              broken;
 161         u16             reserved;
 162         struct w1_family        *f;
 163         int             (*convert)(u8 rom[9]);
 164         int             (*get_conversion_time)(struct w1_slave *sl);
 165         int             (*set_resolution)(struct w1_slave *sl, int val);
 166         int             (*get_resolution)(struct w1_slave *sl);
 167         int             (*write_data)(struct w1_slave *sl, const u8 *data);
 168         bool            bulk_read;
 169 };
 170
 171 /**
 172  * struct w1_therm_family_data - device data
 173  * @rom: ROM device id (64bit Lasered ROM code + 1 CRC byte)
 174  * @refcnt: ref count
 175  * @external_powered:   1 device powered externally,
 176  *                              0 device parasite powered,
 177  *                              -x error or undefined
 178  * @resolution: current device resolution
 179  * @convert_triggered: conversion state of the device
 180  * @conv_time_override: user selected conversion time or CONV_TIME_DEFAULT
 181  * @features: bit mask - enable temperature validity check, poll for completion
 182  * @specific_functions: pointer to struct of device specific function
 183  */
 184 struct w1_therm_family_data {
 185         uint8_t rom[9];
 186         atomic_t refcnt;
 187         int external_powered;
 188         int resolution;
 189         int convert_triggered;
 190         int conv_time_override;
 191         unsigned int features;
 192         struct w1_therm_family_converter *specific_functions;
 193 };
 194
 195 /**
 196  * struct therm_info - store temperature reading
 197  * @rom: read device data (8 data bytes + 1 CRC byte)
 198  * @crc: computed crc from rom
 199  * @verdict: 1 crc checked, 0 crc not matching
 200  */
 201 struct therm_info {
 202         u8 rom[9];
 203         u8 crc;
 204         u8 verdict;
 205 };
 206
 207 /* Hardware Functions declaration */
 208
 209 /**
 210  * reset_select_slave() - reset and select a slave
 211  * @sl: the slave to select
 212  *
 213  * Resets the bus and select the slave by sending a ROM MATCH cmd
 214  * w1_reset_select_slave() from w1_io.c could not be used here because
 215  * it sent a SKIP ROM command if only one device is on the line.
 216  * At the beginning of the such process, sl->master->slave_count is 1 even if
 217  * more devices are on the line, causing collision on the line.
 218  *
 219  * Context: The w1 master lock must be held.
 220  *
 221  * Return: 0 if success, negative kernel error code otherwise.
 222  */
 223 static int reset_select_slave(struct w1_slave *sl);
 224
 225 /**
 226  * convert_t() - Query the device for temperature conversion and read
 227  * @sl: pointer to the slave to read
 228  * @info: pointer to a structure to store the read results
 229  *
 230  * Return: 0 if success, -kernel error code otherwise
 231  */
 232 static int convert_t(struct w1_slave *sl, struct therm_info *info);
 233
 234 /**
 235  * read_scratchpad() - read the data in device RAM
 236  * @sl: pointer to the slave to read
 237  * @info: pointer to a structure to store the read results
 238  *
 239  * Return: 0 if success, -kernel error code otherwise
 240  */
 241 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info);
 242
 243 /**
 244  * write_scratchpad() - write nb_bytes in the device RAM
 245  * @sl: pointer to the slave to write in
 246  * @data: pointer to an array of 3 bytes, as 3 bytes MUST be written
 247  * @nb_bytes: number of bytes to be written (2 for DS18S20, 3 otherwise)
 248  *
 249  * Return: 0 if success, -kernel error code otherwise
 250  */
 251 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes);
 252
 253 /**
 254  * copy_scratchpad() - Copy the content of scratchpad in device EEPROM
 255  * @sl: slave involved
 256  *
 257  * Return: 0 if success, -kernel error code otherwise
 258  */
 259 static int copy_scratchpad(struct w1_slave *sl);
 260
 261 /**
 262  * recall_eeprom() - Restore EEPROM data to device RAM
 263  * @sl: slave involved
 264  *
 265  * Return: 0 if success, -kernel error code otherwise
 266  */
 267 static int recall_eeprom(struct w1_slave *sl);
 268
 269 /**
 270  * read_powermode() - Query the power mode of the slave
 271  * @sl: slave to retrieve the power mode
 272  *
 273  * Ask the device to get its power mode (external or parasite)
 274  * and store the power status in the &struct w1_therm_family_data.
 275  *
 276  * Return:
 277  * * 0 parasite powered device
 278  * * 1 externally powered device
 279  * * <0 kernel error code
 280  */
 281 static int read_powermode(struct w1_slave *sl);
 282
 283 /**
 284  * trigger_bulk_read() - function to trigger a bulk read on the bus
 285  * @dev_master: the device master of the bus
 286  *
 287  * Send a SKIP ROM follow by a CONVERT T commmand on the bus.
 288  * It also set the status flag in each slave &struct w1_therm_family_data
 289  * to signal that a conversion is in progress.
 290  *
 291  * Return: 0 if success, -kernel error code otherwise
 292  */
 293 static int trigger_bulk_read(struct w1_master *dev_master);
 294
 295 /* Sysfs interface declaration */
 296
 297 static ssize_t w1_slave_show(struct device *device,
 298         struct device_attribute *attr, char *buf);
 299
 300 static ssize_t w1_slave_store(struct device *device,
 301         struct device_attribute *attr, const char *buf, size_t size);
 302
 303 static ssize_t w1_seq_show(struct device *device,
 304         struct device_attribute *attr, char *buf);
 305
 306 static ssize_t temperature_show(struct device *device,
 307         struct device_attribute *attr, char *buf);
 308
 309 static ssize_t ext_power_show(struct device *device,
 310         struct device_attribute *attr, char *buf);
 311
 312 static ssize_t resolution_show(struct device *device,
 313         struct device_attribute *attr, char *buf);
 314
 315 static ssize_t resolution_store(struct device *device,
 316         struct device_attribute *attr, const char *buf, size_t size);
 317
 318 static ssize_t eeprom_cmd_store(struct device *device,
 319         struct device_attribute *attr, const char *buf, size_t size);
 320
 321 static ssize_t alarms_store(struct device *device,
 322         struct device_attribute *attr, const char *buf, size_t size);
 323
 324 static ssize_t alarms_show(struct device *device,
 325         struct device_attribute *attr, char *buf);
 326
 327 static ssize_t therm_bulk_read_store(struct device *device,
 328         struct device_attribute *attr, const char *buf, size_t size);
 329
 330 static ssize_t therm_bulk_read_show(struct device *device,
 331         struct device_attribute *attr, char *buf);
 332
 333 static ssize_t conv_time_show(struct device *device,
 334                               struct device_attribute *attr, char *buf);
 335
 336 static ssize_t conv_time_store(struct device *device,
 337                                struct device_attribute *attr, const char *buf,
 338                                size_t size);
 339
 340 static ssize_t features_show(struct device *device,
 341                               struct device_attribute *attr, char *buf);
 342
 343 static ssize_t features_store(struct device *device,
 344                                struct device_attribute *attr, const char *buf,
 345                                size_t size);
 346 /* Attributes declarations */
 347
 348 static DEVICE_ATTR_RW(w1_slave);
 349 static DEVICE_ATTR_RO(w1_seq);
 350 static DEVICE_ATTR_RO(temperature);
 351 static DEVICE_ATTR_RO(ext_power);
 352 static DEVICE_ATTR_RW(resolution);
 353 static DEVICE_ATTR_WO(eeprom_cmd);
 354 static DEVICE_ATTR_RW(alarms);
 355 static DEVICE_ATTR_RW(conv_time);
 356 static DEVICE_ATTR_RW(features);
 357
 358 static DEVICE_ATTR_RW(therm_bulk_read); /* attribut at master level */
 359
 360 /* Interface Functions declaration */
 361
 362 /**
 363  * w1_therm_add_slave() - Called when a new slave is discovered
 364  * @sl: slave just discovered by the master.
 365  *
 366  * Called by the master when the slave is discovered on the bus. Used to
 367  * initialize slave state before the beginning of any communication.
 368  *
 369  * Return: 0 - If success, negative kernel code otherwise
 370  */
 371 static int w1_therm_add_slave(struct w1_slave *sl);
 372
 373 /**
 374  * w1_therm_remove_slave() - Called when a slave is removed
 375  * @sl: slave to be removed.
 376  *
 377  * Called by the master when the slave is considered not to be on the bus
 378  * anymore. Used to free memory.
 379  */
 380 static void w1_therm_remove_slave(struct w1_slave *sl);
 381
 382 /* Family attributes */
 383
 384 static struct attribute *w1_therm_attrs[] = {
 385         &dev_attr_w1_slave.attr,
 386         &dev_attr_temperature.attr,
 387         &dev_attr_ext_power.attr,
 388         &dev_attr_resolution.attr,
 389         &dev_attr_eeprom_cmd.attr,
 390         &dev_attr_alarms.attr,
 391         &dev_attr_conv_time.attr,
 392         &dev_attr_features.attr,
 393         NULL,
 394 };
 395
 396 static struct attribute *w1_ds18s20_attrs[] = {
 397         &dev_attr_w1_slave.attr,
 398         &dev_attr_temperature.attr,
 399         &dev_attr_ext_power.attr,
 400         &dev_attr_eeprom_cmd.attr,
 401         &dev_attr_alarms.attr,
 402         &dev_attr_conv_time.attr,
 403         &dev_attr_features.attr,
 404         NULL,
 405 };
 406
 407 static struct attribute *w1_ds28ea00_attrs[] = {
 408         &dev_attr_w1_slave.attr,
 409         &dev_attr_w1_seq.attr,
 410         &dev_attr_temperature.attr,
 411         &dev_attr_ext_power.attr,
 412         &dev_attr_resolution.attr,
 413         &dev_attr_eeprom_cmd.attr,
 414         &dev_attr_alarms.attr,
 415         &dev_attr_conv_time.attr,
 416         &dev_attr_features.attr,
 417         NULL,
 418 };
 419
 420 /* Attribute groups */
 421
 422 ATTRIBUTE_GROUPS(w1_therm);
 423 ATTRIBUTE_GROUPS(w1_ds18s20);
 424 ATTRIBUTE_GROUPS(w1_ds28ea00);
 425
 426 #if IS_REACHABLE(CONFIG_HWMON)
 427 static int w1_read_temp(struct device *dev, u32 attr, int channel,
 428                         long *val);
 429
 430 static umode_t w1_is_visible(const void *_data, enum hwmon_sensor_types type,
 431                              u32 attr, int channel)
 432 {
 433         return attr == hwmon_temp_input ? 0444 : 0;
 434 }
 435
 436 static int w1_read(struct device *dev, enum hwmon_sensor_types type,
 437                    u32 attr, int channel, long *val)
 438 {
 439         switch (type) {
 440         case hwmon_temp:
 441                 return w1_read_temp(dev, attr, channel, val);
 442         default:
 443                 return -EOPNOTSUPP;
 444         }
 445 }
 446
 447 static const u32 w1_temp_config[] = {
 448         HWMON_T_INPUT,
 449         0
 450 };
 451
 452 static const struct hwmon_channel_info w1_temp = {
 453         .type = hwmon_temp,
 454         .config = w1_temp_config,
 455 };
 456
 457 static const struct hwmon_channel_info *w1_info[] = {
 458         &w1_temp,
 459         NULL
 460 };
 461
 462 static const struct hwmon_ops w1_hwmon_ops = {
 463         .is_visible = w1_is_visible,
 464         .read = w1_read,
 465 };
 466
 467 static const struct hwmon_chip_info w1_chip_info = {
 468         .ops = &w1_hwmon_ops,
 469         .info = w1_info,
 470 };
 471 #define W1_CHIPINFO     (&w1_chip_info)
 472 #else
 473 #define W1_CHIPINFO     NULL
 474 #endif
 475
 476 /* Family operations */
 477
 478 static const struct w1_family_ops w1_therm_fops = {
 479         .add_slave      = w1_therm_add_slave,
 480         .remove_slave   = w1_therm_remove_slave,
 481         .groups         = w1_therm_groups,
 482         .chip_info      = W1_CHIPINFO,
 483 };
 484
 485 static const struct w1_family_ops w1_ds18s20_fops = {
 486         .add_slave      = w1_therm_add_slave,
 487         .remove_slave   = w1_therm_remove_slave,
 488         .groups         = w1_ds18s20_groups,
 489         .chip_info      = W1_CHIPINFO,
 490 };
 491
 492 static const struct w1_family_ops w1_ds28ea00_fops = {
 493         .add_slave      = w1_therm_add_slave,
 494         .remove_slave   = w1_therm_remove_slave,
 495         .groups         = w1_ds28ea00_groups,
 496         .chip_info      = W1_CHIPINFO,
 497 };
 498
 499 /* Family binding operations struct */
 500
 501 static struct w1_family w1_therm_family_DS18S20 = {
 502         .fid = W1_THERM_DS18S20,
 503         .fops = &w1_ds18s20_fops,
 504 };
 505
 506 static struct w1_family w1_therm_family_DS18B20 = {
 507         .fid = W1_THERM_DS18B20,
 508         .fops = &w1_therm_fops,
 509 };
 510
 511 static struct w1_family w1_therm_family_DS1822 = {
 512         .fid = W1_THERM_DS1822,
 513         .fops = &w1_therm_fops,
 514 };
 515
 516 static struct w1_family w1_therm_family_DS28EA00 = {
 517         .fid = W1_THERM_DS28EA00,
 518         .fops = &w1_ds28ea00_fops,
 519 };
 520
 521 static struct w1_family w1_therm_family_DS1825 = {
 522         .fid = W1_THERM_DS1825,
 523         .fops = &w1_therm_fops,
 524 };
 525
 526 /* Device dependent func */
 527
 528 static inline int w1_DS18B20_convert_time(struct w1_slave *sl)
 529 {
 530         int ret;
 531
 532         if (!sl->family_data)
 533                 return -ENODEV; /* device unknown */
 534
 535         if (SLAVE_CONV_TIME_OVERRIDE(sl) != CONV_TIME_DEFAULT)
 536                 return SLAVE_CONV_TIME_OVERRIDE(sl);
 537
 538         /* Return the conversion time, depending on resolution,
 539          * select maximum conversion time among all compatible devices
 540          */
 541         switch (SLAVE_RESOLUTION(sl)) {
 542         case 9:
 543                 ret = 95;
 544                 break;
 545         case 10:
 546                 ret = 190;
 547                 break;
 548         case 11:
 549                 ret = 375;
 550                 break;
 551         case 12:
 552                 ret = 750;
 553                 break;
 554         case 13:
 555                 ret = 850;  /* GX20MH01 only. Datasheet says 500ms, but that's not enough. */
 556                 break;
 557         case 14:
 558                 ret = 1600; /* GX20MH01 only. Datasheet says 1000ms - not enough */
 559                 break;
 560         default:
 561                 ret = 750;
 562         }
 563         return ret;
 564 }
 565
 566 static inline int w1_DS18S20_convert_time(struct w1_slave *sl)
 567 {
 568         if (!sl->family_data)
 569                 return -ENODEV; /* device unknown */
 570
 571         if (SLAVE_CONV_TIME_OVERRIDE(sl) == CONV_TIME_DEFAULT)
 572                 return 750; /* default for DS18S20 */
 573         else
 574                 return SLAVE_CONV_TIME_OVERRIDE(sl);
 575 }
 576
 577 static inline int w1_DS18B20_write_data(struct w1_slave *sl,
 578                                 const u8 *data)
 579 {
 580         return write_scratchpad(sl, data, 3);
 581 }
 582
 583 static inline int w1_DS18S20_write_data(struct w1_slave *sl,
 584                                 const u8 *data)
 585 {
 586         /* No config register */
 587         return write_scratchpad(sl, data, 2);
 588 }
 589
 590 static inline int w1_DS18B20_set_resolution(struct w1_slave *sl, int val)
 591 {
 592         int ret;
 593         struct therm_info info, info2;
 594
 595         /* DS18B20 resolution is 9 to 12 bits */
 596         /* GX20MH01 resolution is 9 to 14 bits */
 597         if (val < W1_THERM_RESOLUTION_MIN || val > W1_THERM_RESOLUTION_MAX)
 598                 return -EINVAL;
 599
 600         /* Calc bit value from resolution */
 601         val = (val - W1_THERM_RESOLUTION_MIN) << W1_THERM_RESOLUTION_SHIFT;
 602
 603         /*
 604          * Read the scratchpad to change only the required bits
 605          * (bit5 & bit 6 from byte 4)
 606          */
 607         ret = read_scratchpad(sl, &info);
 608
 609         if (ret)
 610                 return ret;
 611
 612
 613         info.rom[4] &= ~W1_THERM_RESOLUTION_MASK;
 614         info.rom[4] |= val;
 615
 616         /* Write data in the device RAM */
 617         ret = w1_DS18B20_write_data(sl, info.rom + 2);
 618         if (ret)
 619                 return ret;
 620
 621         /* Have to read back the resolution to verify an actual value
 622          * GX20MH01 and DS18B20 are indistinguishable by family number, but resolutions differ
 623          * Some DS18B20 clones don't support resolution change
 624          */
 625         ret = read_scratchpad(sl, &info2);
 626         if (ret)
 627                 /* Scratchpad read fail */
 628                 return ret;
 629
 630         if ((info2.rom[4] & W1_THERM_RESOLUTION_MASK) == (info.rom[4] & W1_THERM_RESOLUTION_MASK))
 631                 return 0;
 632
 633         /* Resolution verify error */
 634         return -EIO;
 635 }
 636
 637 static inline int w1_DS18B20_get_resolution(struct w1_slave *sl)
 638 {
 639         int ret;
 640         int resolution;
 641         struct therm_info info;
 642
 643         ret = read_scratchpad(sl, &info);
 644
 645         if (ret)
 646                 return ret;
 647
 648         resolution = ((info.rom[4] & W1_THERM_RESOLUTION_MASK) >> W1_THERM_RESOLUTION_SHIFT)
 649                 + W1_THERM_RESOLUTION_MIN;
 650         /* GX20MH01 has one special case:
 651          *   >=14 means 14 bits when getting resolution from bit value.
 652          * Other devices have no more then 12 bits.
 653          */
 654         if (resolution > W1_THERM_RESOLUTION_MAX)
 655                 resolution = W1_THERM_RESOLUTION_MAX;
 656
 657         return resolution;
 658 }
 659
 660 /**
 661  * w1_DS18B20_convert_temp() - temperature computation for DS18B20
 662  * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
 663  *
 664  * Can be called for any DS18B20 compliant device.
 665  *
 666  * Return: value in millidegrees Celsius.
 667  */
 668 static inline int w1_DS18B20_convert_temp(u8 rom[9])
 669 {
 670         u16 bv;
 671         s16 t;
 672
 673         /* Signed 16-bit value to unsigned, cpu order */
 674         bv = le16_to_cpup((__le16 *)rom);
 675
 676         /* Config register bit R2 = 1 - GX20MH01 in 13 or 14 bit resolution mode */
 677         if (rom[4] & 0x80) {
 678                 /* Insert two temperature bits from config register */
 679                 /* Avoid arithmetic shift of signed value */
 680                 bv = (bv << 2) | (rom[4] & 3);
 681                 t = (s16) bv;   /* Degrees, lowest bit is 2^-6 */
 682                 return (int)t * 1000 / 64;      /* Sign-extend to int; millidegrees */
 683         }
 684         t = (s16)bv;    /* Degrees, lowest bit is 2^-4 */
 685         return (int)t * 1000 / 16;      /* Sign-extend to int; millidegrees */
 686 }
 687
 688 /**
 689  * w1_DS18S20_convert_temp() - temperature computation for DS18S20
 690  * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
 691  *
 692  * Can be called for any DS18S20 compliant device.
 693  *
 694  * Return: value in millidegrees Celsius.
 695  */
 696 static inline int w1_DS18S20_convert_temp(u8 rom[9])
 697 {
 698         int t, h;
 699
 700         if (!rom[7]) {
 701                 pr_debug("%s: Invalid argument for conversion\n", __func__);
 702                 return 0;
 703         }
 704
 705         if (rom[1] == 0)
 706                 t = ((s32)rom[0] >> 1)*1000;
 707         else
 708                 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
 709
 710         t -= 250;
 711         h = 1000*((s32)rom[7] - (s32)rom[6]);
 712         h /= (s32)rom[7];
 713         t += h;
 714
 715         return t;
 716 }
 717
 718 /* Device capability description */
 719 /* GX20MH01 device shares family number and structure with DS18B20 */
 720
 721 static struct w1_therm_family_converter w1_therm_families[] = {
 722         {
 723                 .f                              = &w1_therm_family_DS18S20,
 724                 .convert                        = w1_DS18S20_convert_temp,
 725                 .get_conversion_time    = w1_DS18S20_convert_time,
 726                 .set_resolution         = NULL, /* no config register */
 727                 .get_resolution         = NULL, /* no config register */
 728                 .write_data                     = w1_DS18S20_write_data,
 729                 .bulk_read                      = true
 730         },
 731         {
 732                 .f                              = &w1_therm_family_DS1822,
 733                 .convert                        = w1_DS18B20_convert_temp,
 734                 .get_conversion_time    = w1_DS18B20_convert_time,
 735                 .set_resolution         = w1_DS18B20_set_resolution,
 736                 .get_resolution         = w1_DS18B20_get_resolution,
 737                 .write_data                     = w1_DS18B20_write_data,
 738                 .bulk_read                      = true
 739         },
 740         {
 741                 /* Also used for GX20MH01 */
 742                 .f                              = &w1_therm_family_DS18B20,
 743                 .convert                        = w1_DS18B20_convert_temp,
 744                 .get_conversion_time    = w1_DS18B20_convert_time,
 745                 .set_resolution         = w1_DS18B20_set_resolution,
 746                 .get_resolution         = w1_DS18B20_get_resolution,
 747                 .write_data                     = w1_DS18B20_write_data,
 748                 .bulk_read                      = true
 749         },
 750         {
 751                 .f                              = &w1_therm_family_DS28EA00,
 752                 .convert                        = w1_DS18B20_convert_temp,
 753                 .get_conversion_time    = w1_DS18B20_convert_time,
 754                 .set_resolution         = w1_DS18B20_set_resolution,
 755                 .get_resolution         = w1_DS18B20_get_resolution,
 756                 .write_data                     = w1_DS18B20_write_data,
 757                 .bulk_read                      = false
 758         },
 759         {
 760                 .f                              = &w1_therm_family_DS1825,
 761                 .convert                        = w1_DS18B20_convert_temp,
 762                 .get_conversion_time    = w1_DS18B20_convert_time,
 763                 .set_resolution         = w1_DS18B20_set_resolution,
 764                 .get_resolution         = w1_DS18B20_get_resolution,
 765                 .write_data                     = w1_DS18B20_write_data,
 766                 .bulk_read                      = true
 767         }
 768 };
 769
 770 /* Helpers Functions */
 771
 772 /**
 773  * device_family() - Retrieve a pointer on &struct w1_therm_family_converter
 774  * @sl: slave to retrieve the device specific structure
 775  *
 776  * Return: pointer to the slaves's family converter, NULL if not known
 777  */
 778 static struct w1_therm_family_converter *device_family(struct w1_slave *sl)
 779 {
 780         struct w1_therm_family_converter *ret = NULL;
 781         int i;
 782
 783         for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
 784                 if (w1_therm_families[i].f->fid == sl->family->fid) {
 785                         ret = &w1_therm_families[i];
 786                         break;
 787                 }
 788         }
 789         return ret;
 790 }
 791
 792 /**
 793  * bus_mutex_lock() - Acquire the mutex
 794  * @lock: w1 bus mutex to acquire
 795  *
 796  * It try to acquire the mutex W1_THERM_MAX_TRY times and wait
 797  * W1_THERM_RETRY_DELAY between 2 attempts.
 798  *
 799  * Return: true is mutex is acquired and lock, false otherwise
 800  */
 801 static inline bool bus_mutex_lock(struct mutex *lock)
 802 {
 803         int max_trying = W1_THERM_MAX_TRY;
 804
 805         /* try to acquire the mutex, if not, sleep retry_delay before retry) */
 806         while (mutex_lock_interruptible(lock) != 0 && max_trying > 0) {
 807                 unsigned long sleep_rem;
 808
 809                 sleep_rem = msleep_interruptible(W1_THERM_RETRY_DELAY);
 810                 if (!sleep_rem)
 811                         max_trying--;
 812         }
 813
 814         if (!max_trying)
 815                 return false;   /* Didn't acquire the bus mutex */
 816
 817         return true;
 818 }
 819
 820 /**
 821  * check_family_data() - Check if family data and specific functions are present
 822  * @sl: W1 device data
 823  *
 824  * Return: 0 - OK, negative value - error
 825  */
 826 static int check_family_data(struct w1_slave *sl)
 827 {
 828         if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
 829                 dev_info(&sl->dev,
 830                          "%s: Device is not supported by the driver\n", __func__);
 831                 return -EINVAL;  /* No device family */
 832         }
 833         return 0;
 834 }
 835
 836 /**
 837  * bulk_read_support() - check if slave support bulk read
 838  * @sl: device to check the ability
 839  *
 840  * Return: true if bulk read is supported, false if not or error
 841  */
 842 static inline bool bulk_read_support(struct w1_slave *sl)
 843 {
 844         if (SLAVE_SPECIFIC_FUNC(sl))
 845                 return SLAVE_SPECIFIC_FUNC(sl)->bulk_read;
 846
 847         dev_info(&sl->dev,
 848                 "%s: Device not supported by the driver\n", __func__);
 849
 850         return false;  /* No device family */
 851 }
 852
 853 /**
 854  * conversion_time() - get the Tconv for the slave
 855  * @sl: device to get the conversion time
 856  *
 857  * On device supporting resolution settings, conversion time depend
 858  * on the resolution setting. This helper function get the slave timing,
 859  * depending on its current setting.
 860  *
 861  * Return: conversion time in ms, negative values are kernel error code
 862  */
 863 static inline int conversion_time(struct w1_slave *sl)
 864 {
 865         if (SLAVE_SPECIFIC_FUNC(sl))
 866                 return SLAVE_SPECIFIC_FUNC(sl)->get_conversion_time(sl);
 867
 868         dev_info(&sl->dev,
 869                 "%s: Device not supported by the driver\n", __func__);
 870
 871         return -ENODEV;  /* No device family */
 872 }
 873
 874 /**
 875  * temperature_from_RAM() - Convert the read info to temperature
 876  * @sl: device that sent the RAM data
 877  * @rom: read value on the slave device RAM
 878  *
 879  * Device dependent, the function bind the correct computation method.
 880  *
 881  * Return: temperature in 1/1000degC, 0 on error.
 882  */
 883 static inline int temperature_from_RAM(struct w1_slave *sl, u8 rom[9])
 884 {
 885         if (SLAVE_SPECIFIC_FUNC(sl))
 886                 return SLAVE_SPECIFIC_FUNC(sl)->convert(rom);
 887
 888         dev_info(&sl->dev,
 889                 "%s: Device not supported by the driver\n", __func__);
 890
 891         return 0;  /* No device family */
 892 }
 893
 894 /**
 895  * int_to_short() - Safe casting of int to short
 896  *
 897  * @i: integer to be converted to short
 898  *
 899  * Device register use 1 byte to store signed integer.
 900  * This helper function convert the int in a signed short,
 901  * using the min/max values that device can measure as limits.
 902  * min/max values are defined by macro.
 903  *
 904  * Return: a short in the range of min/max value
 905  */
 906 static inline s8 int_to_short(int i)
 907 {
 908         /* Prepare to cast to short by eliminating out of range values */
 909         i = clamp(i, MIN_TEMP, MAX_TEMP);
 910         return (s8) i;
 911 }
 912
 913 /* Interface Functions */
 914
 915 static int w1_therm_add_slave(struct w1_slave *sl)
 916 {
 917         struct w1_therm_family_converter *sl_family_conv;
 918
 919         /* Allocate memory */
 920         sl->family_data = kzalloc(sizeof(struct w1_therm_family_data),
 921                 GFP_KERNEL);
 922         if (!sl->family_data)
 923                 return -ENOMEM;
 924
 925         atomic_set(THERM_REFCNT(sl->family_data), 1);
 926
 927         /* Get a pointer to the device specific function struct */
 928         sl_family_conv = device_family(sl);
 929         if (!sl_family_conv) {
 930                 kfree(sl->family_data);
 931                 return -ENODEV;
 932         }
 933         /* save this pointer to the device structure */
 934         SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv;
 935
 936         if (bulk_read_support(sl)) {
 937                 /*
 938                  * add the sys entry to trigger bulk_read
 939                  * at master level only the 1st time
 940                  */
 941                 if (!bulk_read_device_counter) {
 942                         int err = device_create_file(&sl->master->dev,
 943                                 &dev_attr_therm_bulk_read);
 944
 945                         if (err)
 946                                 dev_warn(&sl->dev,
 947                                 "%s: Device has been added, but bulk read is unavailable. err=%d\n",
 948                                 __func__, err);
 949                 }
 950                 /* Increment the counter */
 951                 bulk_read_device_counter++;
 952         }
 953
 954         /* Getting the power mode of the device {external, parasite} */
 955         SLAVE_POWERMODE(sl) = read_powermode(sl);
 956
 957         if (SLAVE_POWERMODE(sl) < 0) {
 958                 /* no error returned as device has been added */
 959                 dev_warn(&sl->dev,
 960                         "%s: Device has been added, but power_mode may be corrupted. err=%d\n",
 961                          __func__, SLAVE_POWERMODE(sl));
 962         }
 963
 964         /* Getting the resolution of the device */
 965         if (SLAVE_SPECIFIC_FUNC(sl)->get_resolution) {
 966                 SLAVE_RESOLUTION(sl) =
 967                         SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
 968                 if (SLAVE_RESOLUTION(sl) < 0) {
 969                         /* no error returned as device has been added */
 970                         dev_warn(&sl->dev,
 971                                 "%s:Device has been added, but resolution may be corrupted. err=%d\n",
 972                                 __func__, SLAVE_RESOLUTION(sl));
 973                 }
 974         }
 975
 976         /* Finally initialize convert_triggered flag */
 977         SLAVE_CONVERT_TRIGGERED(sl) = 0;
 978
 979         return 0;
 980 }
 981
 982 static void w1_therm_remove_slave(struct w1_slave *sl)
 983 {
 984         int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
 985
 986         if (bulk_read_support(sl)) {
 987                 bulk_read_device_counter--;
 988                 /* Delete the entry if no more device support the feature */
 989                 if (!bulk_read_device_counter)
 990                         device_remove_file(&sl->master->dev,
 991                                 &dev_attr_therm_bulk_read);
 992         }
 993
 994         while (refcnt) {
 995                 msleep(1000);
 996                 refcnt = atomic_read(THERM_REFCNT(sl->family_data));
 997         }
 998         kfree(sl->family_data);
 999         sl->family_data = NULL;
1000 }
1001
1002 /* Hardware Functions */
1003
1004 /* Safe version of reset_select_slave - avoid using the one in w_io.c */
1005 static int reset_select_slave(struct w1_slave *sl)
1006 {
1007         u8 match[9] = { W1_MATCH_ROM, };
1008         u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num));
1009
1010         if (w1_reset_bus(sl->master))
1011                 return -ENODEV;
1012
1013         memcpy(&match[1], &rn, 8);
1014         w1_write_block(sl->master, match, 9);
1015
1016         return 0;
1017 }
1018
1019 /**
1020  * w1_poll_completion - Poll for operation completion, with timeout
1021  * @dev_master: the device master of the bus
1022  * @tout_ms: timeout in milliseconds
1023  *
1024  * The device is answering 0's while an operation is in progress and 1's after it completes
1025  * Timeout may happen if the previous command was not recognised due to a line noise
1026  *
1027  * Return: 0 - OK, negative error - timeout
1028  */
1029 static int w1_poll_completion(struct w1_master *dev_master, int tout_ms)
1030 {
1031         int i;
1032
1033         for (i = 0; i < tout_ms/W1_POLL_PERIOD; i++) {
1034                 /* Delay is before poll, for device to recognize a command */
1035                 msleep(W1_POLL_PERIOD);
1036
1037                 /* Compare all 8 bits to mitigate a noise on the bus */
1038                 if (w1_read_8(dev_master) == 0xFF)
1039                         break;
1040         }
1041         if (i == tout_ms/W1_POLL_PERIOD)
1042                 return -EIO;
1043
1044         return 0;
1045 }
1046
1047 static int convert_t(struct w1_slave *sl, struct therm_info *info)
1048 {
1049         struct w1_master *dev_master = sl->master;
1050         int max_trying = W1_THERM_MAX_TRY;
1051         int t_conv;
1052         int ret = -ENODEV;
1053         bool strong_pullup;
1054
1055         if (!sl->family_data)
1056                 goto error;
1057
1058         strong_pullup = (w1_strong_pullup == 2 ||
1059                                         (!SLAVE_POWERMODE(sl) &&
1060                                         w1_strong_pullup));
1061
1062         if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1063                 dev_warn(&sl->dev,
1064                         "%s: Disabling W1_THERM_POLL_COMPLETION in parasite power mode.\n",
1065                         __func__);
1066                 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
1067         }
1068
1069         /* get conversion duration device and id dependent */
1070         t_conv = conversion_time(sl);
1071
1072         memset(info->rom, 0, sizeof(info->rom));
1073
1074         /* prevent the slave from going away in sleep */
1075         atomic_inc(THERM_REFCNT(sl->family_data));
1076
1077         if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1078                 ret = -EAGAIN;  /* Didn't acquire the mutex */
1079                 goto dec_refcnt;
1080         }
1081
1082         while (max_trying-- && ret) { /* ret should be 0 */
1083
1084                 info->verdict = 0;
1085                 info->crc = 0;
1086                 /* safe version to select slave */
1087                 if (!reset_select_slave(sl)) {
1088                         unsigned long sleep_rem;
1089
1090                         /* 750ms strong pullup (or delay) after the convert */
1091                         if (strong_pullup)
1092                                 w1_next_pullup(dev_master, t_conv);
1093
1094                         w1_write_8(dev_master, W1_CONVERT_TEMP);
1095
1096                         if (strong_pullup) { /*some device need pullup */
1097                                 sleep_rem = msleep_interruptible(t_conv);
1098                                 if (sleep_rem != 0) {
1099                                         ret = -EINTR;
1100                                         goto mt_unlock;
1101                                 }
1102                                 mutex_unlock(&dev_master->bus_mutex);
1103                         } else { /*no device need pullup */
1104                                 if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1105                                         ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1106                                         if (ret) {
1107                                                 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1108                                                 goto mt_unlock;
1109                                         }
1110                                         mutex_unlock(&dev_master->bus_mutex);
1111                                 } else {
1112                                         /* Fixed delay */
1113                                         mutex_unlock(&dev_master->bus_mutex);
1114                                         sleep_rem = msleep_interruptible(t_conv);
1115                                         if (sleep_rem != 0) {
1116                                                 ret = -EINTR;
1117                                                 goto dec_refcnt;
1118                                         }
1119                                 }
1120                         }
1121                         ret = read_scratchpad(sl, info);
1122
1123                         /* If enabled, check for conversion success */
1124                         if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) &&
1125                                 (info->rom[6] == 0xC) &&
1126                                 ((info->rom[1] == 0x5 && info->rom[0] == 0x50) ||
1127                                 (info->rom[1] == 0x7 && info->rom[0] == 0xFF))
1128                         ) {
1129                                 /* Invalid reading (scratchpad byte 6 = 0xC)
1130                                  * due to insufficient conversion time
1131                                  * or power failure.
1132                                  */
1133                                 ret = -EIO;
1134                         }
1135
1136                         goto dec_refcnt;
1137                 }
1138
1139         }
1140
1141 mt_unlock:
1142         mutex_unlock(&dev_master->bus_mutex);
1143 dec_refcnt:
1144         atomic_dec(THERM_REFCNT(sl->family_data));
1145 error:
1146         return ret;
1147 }
1148
1149 static int conv_time_measure(struct w1_slave *sl, int *conv_time)
1150 {
1151         struct therm_info inf,
1152                 *info = &inf;
1153         struct w1_master *dev_master = sl->master;
1154         int max_trying = W1_THERM_MAX_TRY;
1155         int ret = -ENODEV;
1156         bool strong_pullup;
1157
1158         if (!sl->family_data)
1159                 goto error;
1160
1161         strong_pullup = (w1_strong_pullup == 2 ||
1162                 (!SLAVE_POWERMODE(sl) &&
1163                 w1_strong_pullup));
1164
1165         if (strong_pullup) {
1166                 pr_info("%s: Measure with strong_pullup is not supported.\n", __func__);
1167                 return -EINVAL;
1168         }
1169
1170         memset(info->rom, 0, sizeof(info->rom));
1171
1172         /* prevent the slave from going away in sleep */
1173         atomic_inc(THERM_REFCNT(sl->family_data));
1174
1175         if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1176                 ret = -EAGAIN;  /* Didn't acquire the mutex */
1177                 goto dec_refcnt;
1178         }
1179
1180         while (max_trying-- && ret) { /* ret should be 0 */
1181                 info->verdict = 0;
1182                 info->crc = 0;
1183                 /* safe version to select slave */
1184                 if (!reset_select_slave(sl)) {
1185                         int j_start, j_end;
1186
1187                         /*no device need pullup */
1188                         w1_write_8(dev_master, W1_CONVERT_TEMP);
1189
1190                         j_start = jiffies;
1191                         ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1192                         if (ret) {
1193                                 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1194                                 goto mt_unlock;
1195                         }
1196                         j_end = jiffies;
1197                         /* 1.2x increase for variation and changes over temperature range */
1198                         *conv_time = jiffies_to_msecs(j_end-j_start)*12/10;
1199                         pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n",
1200                                 *conv_time, HZ);
1201                         if (*conv_time <= CONV_TIME_MEASURE) {
1202                                 ret = -EIO;
1203                                 goto mt_unlock;
1204                         }
1205                         mutex_unlock(&dev_master->bus_mutex);
1206                         ret = read_scratchpad(sl, info);
1207                         goto dec_refcnt;
1208                 }
1209
1210         }
1211 mt_unlock:
1212         mutex_unlock(&dev_master->bus_mutex);
1213 dec_refcnt:
1214         atomic_dec(THERM_REFCNT(sl->family_data));
1215 error:
1216         return ret;
1217 }
1218
1219 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info)
1220 {
1221         struct w1_master *dev_master = sl->master;
1222         int max_trying = W1_THERM_MAX_TRY;
1223         int ret = -ENODEV;
1224
1225         info->verdict = 0;
1226
1227         if (!sl->family_data)
1228                 goto error;
1229
1230         memset(info->rom, 0, sizeof(info->rom));
1231
1232         /* prevent the slave from going away in sleep */
1233         atomic_inc(THERM_REFCNT(sl->family_data));
1234
1235         if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1236                 ret = -EAGAIN;  /* Didn't acquire the mutex */
1237                 goto dec_refcnt;
1238         }
1239
1240         while (max_trying-- && ret) { /* ret should be 0 */
1241                 /* safe version to select slave */
1242                 if (!reset_select_slave(sl)) {
1243                         u8 nb_bytes_read;
1244
1245                         w1_write_8(dev_master, W1_READ_SCRATCHPAD);
1246
1247                         nb_bytes_read = w1_read_block(dev_master, info->rom, 9);
1248                         if (nb_bytes_read != 9) {
1249                                 dev_warn(&sl->dev,
1250                                         "w1_read_block(): returned %u instead of 9.\n",
1251                                         nb_bytes_read);
1252                                 ret = -EIO;
1253                         }
1254
1255                         info->crc = w1_calc_crc8(info->rom, 8);
1256
1257                         if (info->rom[8] == info->crc) {
1258                                 info->verdict = 1;
1259                                 ret = 0;
1260                         } else
1261                                 ret = -EIO; /* CRC not checked */
1262                 }
1263
1264         }
1265         mutex_unlock(&dev_master->bus_mutex);
1266
1267 dec_refcnt:
1268         atomic_dec(THERM_REFCNT(sl->family_data));
1269 error:
1270         return ret;
1271 }
1272
1273 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes)
1274 {
1275         struct w1_master *dev_master = sl->master;
1276         int max_trying = W1_THERM_MAX_TRY;
1277         int ret = -ENODEV;
1278
1279         if (!sl->family_data)
1280                 goto error;
1281
1282         /* prevent the slave from going away in sleep */
1283         atomic_inc(THERM_REFCNT(sl->family_data));
1284
1285         if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1286                 ret = -EAGAIN;  /* Didn't acquire the mutex */
1287                 goto dec_refcnt;
1288         }
1289
1290         while (max_trying-- && ret) { /* ret should be 0 */
1291                 /* safe version to select slave */
1292                 if (!reset_select_slave(sl)) {
1293                         w1_write_8(dev_master, W1_WRITE_SCRATCHPAD);
1294                         w1_write_block(dev_master, data, nb_bytes);
1295                         ret = 0;
1296                 }
1297         }
1298         mutex_unlock(&dev_master->bus_mutex);
1299
1300 dec_refcnt:
1301         atomic_dec(THERM_REFCNT(sl->family_data));
1302 error:
1303         return ret;
1304 }
1305
1306 static int copy_scratchpad(struct w1_slave *sl)
1307 {
1308         struct w1_master *dev_master = sl->master;
1309         int max_trying = W1_THERM_MAX_TRY;
1310         int t_write, ret = -ENODEV;
1311         bool strong_pullup;
1312
1313         if (!sl->family_data)
1314                 goto error;
1315
1316         t_write = W1_THERM_EEPROM_WRITE_DELAY;
1317         strong_pullup = (w1_strong_pullup == 2 ||
1318                                         (!SLAVE_POWERMODE(sl) &&
1319                                         w1_strong_pullup));
1320
1321         /* prevent the slave from going away in sleep */
1322         atomic_inc(THERM_REFCNT(sl->family_data));
1323
1324         if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1325                 ret = -EAGAIN;  /* Didn't acquire the mutex */
1326                 goto dec_refcnt;
1327         }
1328
1329         while (max_trying-- && ret) { /* ret should be 0 */
1330                 /* safe version to select slave */
1331                 if (!reset_select_slave(sl)) {
1332                         unsigned long sleep_rem;
1333
1334                         /* 10ms strong pullup (or delay) after the convert */
1335                         if (strong_pullup)
1336                                 w1_next_pullup(dev_master, t_write);
1337
1338                         w1_write_8(dev_master, W1_COPY_SCRATCHPAD);
1339
1340                         if (strong_pullup) {
1341                                 sleep_rem = msleep_interruptible(t_write);
1342                                 if (sleep_rem != 0) {
1343                                         ret = -EINTR;
1344                                         goto mt_unlock;
1345                                 }
1346                         }
1347                         ret = 0;
1348                 }
1349
1350         }
1351
1352 mt_unlock:
1353         mutex_unlock(&dev_master->bus_mutex);
1354 dec_refcnt:
1355         atomic_dec(THERM_REFCNT(sl->family_data));
1356 error:
1357         return ret;
1358 }
1359
1360 static int recall_eeprom(struct w1_slave *sl)
1361 {
1362         struct w1_master *dev_master = sl->master;
1363         int max_trying = W1_THERM_MAX_TRY;
1364         int ret = -ENODEV;
1365
1366         if (!sl->family_data)
1367                 goto error;
1368
1369         /* prevent the slave from going away in sleep */
1370         atomic_inc(THERM_REFCNT(sl->family_data));
1371
1372         if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1373                 ret = -EAGAIN;  /* Didn't acquire the mutex */
1374                 goto dec_refcnt;
1375         }
1376
1377         while (max_trying-- && ret) { /* ret should be 0 */
1378                 /* safe version to select slave */
1379                 if (!reset_select_slave(sl)) {
1380
1381                         w1_write_8(dev_master, W1_RECALL_EEPROM);
1382                         ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM);
1383                 }
1384
1385         }
1386
1387         mutex_unlock(&dev_master->bus_mutex);
1388
1389 dec_refcnt:
1390         atomic_dec(THERM_REFCNT(sl->family_data));
1391 error:
1392         return ret;
1393 }
1394
1395 static int read_powermode(struct w1_slave *sl)
1396 {
1397         struct w1_master *dev_master = sl->master;
1398         int max_trying = W1_THERM_MAX_TRY;
1399         int  ret = -ENODEV;
1400
1401         if (!sl->family_data)
1402                 goto error;
1403
1404         /* prevent the slave from going away in sleep */
1405         atomic_inc(THERM_REFCNT(sl->family_data));
1406
1407         if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1408                 ret = -EAGAIN;  /* Didn't acquire the mutex */
1409                 goto dec_refcnt;
1410         }
1411
1412         while ((max_trying--) && (ret < 0)) {
1413                 /* safe version to select slave */
1414                 if (!reset_select_slave(sl)) {
1415                         w1_write_8(dev_master, W1_READ_PSUPPLY);
1416                         /*
1417                          * Emit a read time slot and read only one bit,
1418                          * 1 is externally powered,
1419                          * 0 is parasite powered
1420                          */
1421                         ret = w1_touch_bit(dev_master, 1);
1422                         /* ret should be either 1 either 0 */
1423                 }
1424         }
1425         mutex_unlock(&dev_master->bus_mutex);
1426
1427 dec_refcnt:
1428         atomic_dec(THERM_REFCNT(sl->family_data));
1429 error:
1430         return ret;
1431 }
1432
1433 static int trigger_bulk_read(struct w1_master *dev_master)
1434 {
1435         struct w1_slave *sl = NULL; /* used to iterate through slaves */
1436         int max_trying = W1_THERM_MAX_TRY;
1437         int t_conv = 0;
1438         int ret = -ENODEV;
1439         bool strong_pullup = false;
1440
1441         /*
1442          * Check whether there are parasite powered device on the bus,
1443          * and compute duration of conversion for these devices
1444          * so we can apply a strong pullup if required
1445          */
1446         list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1447                 if (!sl->family_data)
1448                         goto error;
1449                 if (bulk_read_support(sl)) {
1450                         int t_cur = conversion_time(sl);
1451
1452                         t_conv = t_cur > t_conv ? t_cur : t_conv;
1453                         strong_pullup = strong_pullup ||
1454                                         (w1_strong_pullup == 2 ||
1455                                         (!SLAVE_POWERMODE(sl) &&
1456                                         w1_strong_pullup));
1457                 }
1458         }
1459
1460         /*
1461          * t_conv is the max conversion time required on the bus
1462          * If its 0, no device support the bulk read feature
1463          */
1464         if (!t_conv)
1465                 goto error;
1466
1467         if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1468                 ret = -EAGAIN;  /* Didn't acquire the mutex */
1469                 goto error;
1470         }
1471
1472         while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */
1473
1474                 if (!w1_reset_bus(dev_master)) {        /* Just reset the bus */
1475                         unsigned long sleep_rem;
1476
1477                         w1_write_8(dev_master, W1_SKIP_ROM);
1478
1479                         if (strong_pullup)      /* Apply pullup if required */
1480                                 w1_next_pullup(dev_master, t_conv);
1481
1482                         w1_write_8(dev_master, W1_CONVERT_TEMP);
1483
1484                         /* set a flag to instruct that converT pending */
1485                         list_for_each_entry(sl,
1486                                 &dev_master->slist, w1_slave_entry) {
1487                                 if (bulk_read_support(sl))
1488                                         SLAVE_CONVERT_TRIGGERED(sl) = -1;
1489                         }
1490
1491                         if (strong_pullup) { /* some device need pullup */
1492                                 sleep_rem = msleep_interruptible(t_conv);
1493                                 if (sleep_rem != 0) {
1494                                         ret = -EINTR;
1495                                         goto mt_unlock;
1496                                 }
1497                                 mutex_unlock(&dev_master->bus_mutex);
1498                         } else {
1499                                 mutex_unlock(&dev_master->bus_mutex);
1500                                 sleep_rem = msleep_interruptible(t_conv);
1501                                 if (sleep_rem != 0) {
1502                                         ret = -EINTR;
1503                                         goto set_flag;
1504                                 }
1505                         }
1506                         ret = 0;
1507                         goto set_flag;
1508                 }
1509         }
1510
1511 mt_unlock:
1512         mutex_unlock(&dev_master->bus_mutex);
1513 set_flag:
1514         /* set a flag to register convsersion is done */
1515         list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1516                 if (bulk_read_support(sl))
1517                         SLAVE_CONVERT_TRIGGERED(sl) = 1;
1518         }
1519 error:
1520         return ret;
1521 }
1522
1523 /* Sysfs Interface definition */
1524
1525 static ssize_t w1_slave_show(struct device *device,
1526                              struct device_attribute *attr, char *buf)
1527 {
1528         struct w1_slave *sl = dev_to_w1_slave(device);
1529         struct therm_info info;
1530         u8 *family_data = sl->family_data;
1531         int ret, i;
1532         ssize_t c = PAGE_SIZE;
1533
1534         if (bulk_read_support(sl)) {
1535                 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1536                         dev_dbg(device,
1537                                 "%s: Conversion in progress, retry later\n",
1538                                 __func__);
1539                         return 0;
1540                 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1541                         /* A bulk read has been issued, read the device RAM */
1542                         ret = read_scratchpad(sl, &info);
1543                         SLAVE_CONVERT_TRIGGERED(sl) = 0;
1544                 } else
1545                         ret = convert_t(sl, &info);
1546         } else
1547                 ret = convert_t(sl, &info);
1548
1549         if (ret < 0) {
1550                 dev_dbg(device,
1551                         "%s: Temperature data may be corrupted. err=%d\n",
1552                         __func__, ret);
1553                 return 0;
1554         }
1555
1556         for (i = 0; i < 9; ++i)
1557                 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]);
1558         c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
1559                       info.crc, (info.verdict) ? "YES" : "NO");
1560
1561         if (info.verdict)
1562                 memcpy(family_data, info.rom, sizeof(info.rom));
1563         else
1564                 dev_warn(device, "%s:Read failed CRC check\n", __func__);
1565
1566         for (i = 0; i < 9; ++i)
1567                 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ",
1568                               ((u8 *)family_data)[i]);
1569
1570         c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
1571                         temperature_from_RAM(sl, info.rom));
1572
1573         ret = PAGE_SIZE - c;
1574         return ret;
1575 }
1576
1577 static ssize_t w1_slave_store(struct device *device,
1578                               struct device_attribute *attr, const char *buf,
1579                               size_t size)
1580 {
1581         int val, ret = 0;
1582         struct w1_slave *sl = dev_to_w1_slave(device);
1583
1584         ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1585
1586         if (ret) {      /* conversion error */
1587                 dev_info(device,
1588                         "%s: conversion error. err= %d\n", __func__, ret);
1589                 return size;    /* return size to avoid call back again */
1590         }
1591
1592         if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1593                 dev_info(device,
1594                         "%s: Device not supported by the driver\n", __func__);
1595                 return size;  /* No device family */
1596         }
1597
1598         if (val == 0)   /* val=0 : trigger a EEPROM save */
1599                 ret = copy_scratchpad(sl);
1600         else {
1601                 if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution)
1602                         ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1603         }
1604
1605         if (ret) {
1606                 dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret);
1607                 /* Propagate error to userspace */
1608                 return ret;
1609         }
1610         SLAVE_RESOLUTION(sl) = val;
1611         /* Reset the conversion time to default - it depends on resolution */
1612         SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1613
1614         return size; /* always return size to avoid infinite calling */
1615 }
1616
1617 static ssize_t temperature_show(struct device *device,
1618         struct device_attribute *attr, char *buf)
1619 {
1620         struct w1_slave *sl = dev_to_w1_slave(device);
1621         struct therm_info info;
1622         int ret = 0;
1623
1624         if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1625                 dev_info(device,
1626                         "%s: Device not supported by the driver\n", __func__);
1627                 return 0;  /* No device family */
1628         }
1629
1630         if (bulk_read_support(sl)) {
1631                 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1632                         dev_dbg(device,
1633                                 "%s: Conversion in progress, retry later\n",
1634                                 __func__);
1635                         return 0;
1636                 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1637                         /* A bulk read has been issued, read the device RAM */
1638                         ret = read_scratchpad(sl, &info);
1639                         SLAVE_CONVERT_TRIGGERED(sl) = 0;
1640                 } else
1641                         ret = convert_t(sl, &info);
1642         } else
1643                 ret = convert_t(sl, &info);
1644
1645         if (ret < 0) {
1646                 dev_dbg(device,
1647                         "%s: Temperature data may be corrupted. err=%d\n",
1648                         __func__, ret);
1649                 return 0;
1650         }
1651
1652         return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom));
1653 }
1654
1655 static ssize_t ext_power_show(struct device *device,
1656         struct device_attribute *attr, char *buf)
1657 {
1658         struct w1_slave *sl = dev_to_w1_slave(device);
1659
1660         if (!sl->family_data) {
1661                 dev_info(device,
1662                         "%s: Device not supported by the driver\n", __func__);
1663                 return 0;  /* No device family */
1664         }
1665
1666         /* Getting the power mode of the device {external, parasite} */
1667         SLAVE_POWERMODE(sl) = read_powermode(sl);
1668
1669         if (SLAVE_POWERMODE(sl) < 0) {
1670                 dev_dbg(device,
1671                         "%s: Power_mode may be corrupted. err=%d\n",
1672                         __func__, SLAVE_POWERMODE(sl));
1673         }
1674         return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl));
1675 }
1676
1677 static ssize_t resolution_show(struct device *device,
1678         struct device_attribute *attr, char *buf)
1679 {
1680         struct w1_slave *sl = dev_to_w1_slave(device);
1681
1682         if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1683                 dev_info(device,
1684                         "%s: Device not supported by the driver\n", __func__);
1685                 return 0;  /* No device family */
1686         }
1687
1688         /* get the correct function depending on the device */
1689         SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
1690         if (SLAVE_RESOLUTION(sl) < 0) {
1691                 dev_dbg(device,
1692                         "%s: Resolution may be corrupted. err=%d\n",
1693                         __func__, SLAVE_RESOLUTION(sl));
1694         }
1695
1696         return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl));
1697 }
1698
1699 static ssize_t resolution_store(struct device *device,
1700         struct device_attribute *attr, const char *buf, size_t size)
1701 {
1702         struct w1_slave *sl = dev_to_w1_slave(device);
1703         int val;
1704         int ret = 0;
1705
1706         ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1707
1708         if (ret) {      /* conversion error */
1709                 dev_info(device,
1710                         "%s: conversion error. err= %d\n", __func__, ret);
1711                 return size;    /* return size to avoid call back again */
1712         }
1713
1714         if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1715                 dev_info(device,
1716                         "%s: Device not supported by the driver\n", __func__);
1717                 return size;  /* No device family */
1718         }
1719
1720         /*
1721          * Don't deal with the val enterd by user,
1722          * only device knows what is correct or not
1723          */
1724
1725         /* get the correct function depending on the device */
1726         ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1727
1728         if (ret)
1729                 return ret;
1730
1731         SLAVE_RESOLUTION(sl) = val;
1732         /* Reset the conversion time to default because it depends on resolution */
1733         SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1734
1735         return size;
1736 }
1737
1738 static ssize_t eeprom_cmd_store(struct device *device,
1739         struct device_attribute *attr, const char *buf, size_t size)
1740 {
1741         struct w1_slave *sl = dev_to_w1_slave(device);
1742         int ret = -EINVAL; /* Invalid argument */
1743
1744         if (size == sizeof(EEPROM_CMD_WRITE)) {
1745                 if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1))
1746                         ret = copy_scratchpad(sl);
1747         } else if (size == sizeof(EEPROM_CMD_READ)) {
1748                 if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1))
1749                         ret = recall_eeprom(sl);
1750         }
1751
1752         if (ret)
1753                 dev_info(device, "%s: error in process %d\n", __func__, ret);
1754
1755         return size;
1756 }
1757
1758 static ssize_t alarms_show(struct device *device,
1759         struct device_attribute *attr, char *buf)
1760 {
1761         struct w1_slave *sl = dev_to_w1_slave(device);
1762         int ret;
1763         s8 th = 0, tl = 0;
1764         struct therm_info scratchpad;
1765
1766         ret = read_scratchpad(sl, &scratchpad);
1767
1768         if (!ret)       {
1769                 th = scratchpad.rom[2]; /* TH is byte 2 */
1770                 tl = scratchpad.rom[3]; /* TL is byte 3 */
1771         } else {
1772                 dev_info(device,
1773                         "%s: error reading alarms register %d\n",
1774                         __func__, ret);
1775         }
1776
1777         return sprintf(buf, "%hd %hd\n", tl, th);
1778 }
1779
1780 static ssize_t alarms_store(struct device *device,
1781         struct device_attribute *attr, const char *buf, size_t size)
1782 {
1783         struct w1_slave *sl = dev_to_w1_slave(device);
1784         struct therm_info info;
1785         u8 new_config_register[3];      /* array of data to be written */
1786         int temp, ret;
1787         char *token = NULL;
1788         s8 tl, th;      /* 1 byte per value + temp ring order */
1789         char *p_args, *orig;
1790
1791         p_args = orig = kmalloc(size, GFP_KERNEL);
1792         /* Safe string copys as buf is const */
1793         if (!p_args) {
1794                 dev_warn(device,
1795                         "%s: error unable to allocate memory %d\n",
1796                         __func__, -ENOMEM);
1797                 return size;
1798         }
1799         strcpy(p_args, buf);
1800
1801         /* Split string using space char */
1802         token = strsep(&p_args, " ");
1803
1804         if (!token)     {
1805                 dev_info(device,
1806                         "%s: error parsing args %d\n", __func__, -EINVAL);
1807                 goto free_m;
1808         }
1809
1810         /* Convert 1st entry to int */
1811         ret = kstrtoint (token, 10, &temp);
1812         if (ret) {
1813                 dev_info(device,
1814                         "%s: error parsing args %d\n", __func__, ret);
1815                 goto free_m;
1816         }
1817
1818         tl = int_to_short(temp);
1819
1820         /* Split string using space char */
1821         token = strsep(&p_args, " ");
1822         if (!token)     {
1823                 dev_info(device,
1824                         "%s: error parsing args %d\n", __func__, -EINVAL);
1825                 goto free_m;
1826         }
1827         /* Convert 2nd entry to int */
1828         ret = kstrtoint (token, 10, &temp);
1829         if (ret) {
1830                 dev_info(device,
1831                         "%s: error parsing args %d\n", __func__, ret);
1832                 goto free_m;
1833         }
1834
1835         /* Prepare to cast to short by eliminating out of range values */
1836         th = int_to_short(temp);
1837
1838         /* Reorder if required th and tl */
1839         if (tl > th)
1840                 swap(tl, th);
1841
1842         /*
1843          * Read the scratchpad to change only the required bits
1844          * (th : byte 2 - tl: byte 3)
1845          */
1846         ret = read_scratchpad(sl, &info);
1847         if (!ret) {
1848                 new_config_register[0] = th;    /* Byte 2 */
1849                 new_config_register[1] = tl;    /* Byte 3 */
1850                 new_config_register[2] = info.rom[4];/* Byte 4 */
1851         } else {
1852                 dev_info(device,
1853                         "%s: error reading from the slave device %d\n",
1854                         __func__, ret);
1855                 goto free_m;
1856         }
1857
1858         /* Write data in the device RAM */
1859         if (!SLAVE_SPECIFIC_FUNC(sl)) {
1860                 dev_info(device,
1861                         "%s: Device not supported by the driver %d\n",
1862                         __func__, -ENODEV);
1863                 goto free_m;
1864         }
1865
1866         ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register);
1867         if (ret)
1868                 dev_info(device,
1869                         "%s: error writing to the slave device %d\n",
1870                         __func__, ret);
1871
1872 free_m:
1873         /* free allocated memory */
1874         kfree(orig);
1875
1876         return size;
1877 }
1878
1879 static ssize_t therm_bulk_read_store(struct device *device,
1880         struct device_attribute *attr, const char *buf, size_t size)
1881 {
1882         struct w1_master *dev_master = dev_to_w1_master(device);
1883         int ret = -EINVAL; /* Invalid argument */
1884
1885         if (size == sizeof(BULK_TRIGGER_CMD))
1886                 if (!strncmp(buf, BULK_TRIGGER_CMD,
1887                                 sizeof(BULK_TRIGGER_CMD)-1))
1888                         ret = trigger_bulk_read(dev_master);
1889
1890         if (ret)
1891                 dev_info(device,
1892                         "%s: unable to trigger a bulk read on the bus. err=%d\n",
1893                         __func__, ret);
1894
1895         return size;
1896 }
1897
1898 static ssize_t therm_bulk_read_show(struct device *device,
1899         struct device_attribute *attr, char *buf)
1900 {
1901         struct w1_master *dev_master = dev_to_w1_master(device);
1902         struct w1_slave *sl = NULL;
1903         int ret = 0;
1904
1905         list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1906                 if (sl->family_data) {
1907                         if (bulk_read_support(sl)) {
1908                                 if (SLAVE_CONVERT_TRIGGERED(sl) == -1) {
1909                                         ret = -1;
1910                                         goto show_result;
1911                                 }
1912                                 if (SLAVE_CONVERT_TRIGGERED(sl) == 1)
1913                                         /* continue to check other slaves */
1914                                         ret = 1;
1915                         }
1916                 }
1917         }
1918 show_result:
1919         return sprintf(buf, "%d\n", ret);
1920 }
1921
1922 static ssize_t conv_time_show(struct device *device,
1923         struct device_attribute *attr, char *buf)
1924 {
1925         struct w1_slave *sl = dev_to_w1_slave(device);
1926
1927         if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1928                 dev_info(device,
1929                         "%s: Device is not supported by the driver\n", __func__);
1930                 return 0;  /* No device family */
1931         }
1932         return sprintf(buf, "%d\n", conversion_time(sl));
1933 }
1934
1935 static ssize_t conv_time_store(struct device *device,
1936         struct device_attribute *attr, const char *buf, size_t size)
1937 {
1938         int val, ret = 0;
1939         struct w1_slave *sl = dev_to_w1_slave(device);
1940
1941         if (kstrtoint(buf, 10, &val)) /* converting user entry to int */
1942                 return -EINVAL;
1943
1944         if (check_family_data(sl))
1945                 return -ENODEV;
1946
1947         if (val != CONV_TIME_MEASURE) {
1948                 if (val >= CONV_TIME_DEFAULT)
1949                         SLAVE_CONV_TIME_OVERRIDE(sl) = val;
1950                 else
1951                         return -EINVAL;
1952
1953         } else {
1954                 int conv_time;
1955
1956                 ret = conv_time_measure(sl, &conv_time);
1957                 if (ret)
1958                         return -EIO;
1959                 SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time;
1960         }
1961         return size;
1962 }
1963
1964 static ssize_t features_show(struct device *device,
1965                              struct device_attribute *attr, char *buf)
1966 {
1967         struct w1_slave *sl = dev_to_w1_slave(device);
1968
1969         if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1970                 dev_info(device,
1971                          "%s: Device not supported by the driver\n", __func__);
1972                 return 0;  /* No device family */
1973         }
1974         return sprintf(buf, "%u\n", SLAVE_FEATURES(sl));
1975 }
1976
1977 static ssize_t features_store(struct device *device,
1978                               struct device_attribute *attr, const char *buf, size_t size)
1979 {
1980         int val, ret = 0;
1981         bool strong_pullup;
1982         struct w1_slave *sl = dev_to_w1_slave(device);
1983
1984         ret = kstrtouint(buf, 10, &val); /* converting user entry to int */
1985         if (ret)
1986                 return -EINVAL;  /* invalid number */
1987
1988         if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1989                 dev_info(device, "%s: Device not supported by the driver\n", __func__);
1990                 return -ENODEV;
1991         }
1992
1993         if ((val & W1_THERM_FEATURES_MASK) != val)
1994                 return -EINVAL;
1995
1996         SLAVE_FEATURES(sl) = val;
1997
1998         strong_pullup = (w1_strong_pullup == 2 ||
1999                          (!SLAVE_POWERMODE(sl) &&
2000                           w1_strong_pullup));
2001
2002         if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
2003                 dev_warn(&sl->dev,
2004                          "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n",
2005                          __func__);
2006                 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
2007         }
2008
2009         return size;
2010 }
2011
2012 #if IS_REACHABLE(CONFIG_HWMON)
2013 static int w1_read_temp(struct device *device, u32 attr, int channel,
2014                         long *val)
2015 {
2016         struct w1_slave *sl = dev_get_drvdata(device);
2017         struct therm_info info;
2018         int ret;
2019
2020         switch (attr) {
2021         case hwmon_temp_input:
2022                 ret = convert_t(sl, &info);
2023                 if (ret)
2024                         return ret;
2025
2026                 if (!info.verdict) {
2027                         ret = -EIO;
2028                         return ret;
2029                 }
2030
2031                 *val = temperature_from_RAM(sl, info.rom);
2032                 ret = 0;
2033                 break;
2034         default:
2035                 ret = -EOPNOTSUPP;
2036                 break;
2037         }
2038
2039         return ret;
2040 }
2041 #endif
2042
2043 #define W1_42_CHAIN     0x99
2044 #define W1_42_CHAIN_OFF 0x3C
2045 #define W1_42_CHAIN_OFF_INV     0xC3
2046 #define W1_42_CHAIN_ON  0x5A
2047 #define W1_42_CHAIN_ON_INV      0xA5
2048 #define W1_42_CHAIN_DONE 0x96
2049 #define W1_42_CHAIN_DONE_INV 0x69
2050 #define W1_42_COND_READ 0x0F
2051 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA
2052 #define W1_42_FINISHED_BYTE 0xFF
2053 static ssize_t w1_seq_show(struct device *device,
2054         struct device_attribute *attr, char *buf)
2055 {
2056         struct w1_slave *sl = dev_to_w1_slave(device);
2057         ssize_t c = PAGE_SIZE;
2058         int i;
2059         u8 ack;
2060         u64 rn;
2061         struct w1_reg_num *reg_num;
2062         int seq = 0;
2063
2064         mutex_lock(&sl->master->bus_mutex);
2065         /* Place all devices in CHAIN state */
2066         if (w1_reset_bus(sl->master))
2067                 goto error;
2068         w1_write_8(sl->master, W1_SKIP_ROM);
2069         w1_write_8(sl->master, W1_42_CHAIN);
2070         w1_write_8(sl->master, W1_42_CHAIN_ON);
2071         w1_write_8(sl->master, W1_42_CHAIN_ON_INV);
2072         msleep(sl->master->pullup_duration);
2073
2074         /* check for acknowledgment */
2075         ack = w1_read_8(sl->master);
2076         if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2077                 goto error;
2078
2079         /* In case the bus fails to send 0xFF, limit */
2080         for (i = 0; i <= 64; i++) {
2081                 if (w1_reset_bus(sl->master))
2082                         goto error;
2083
2084                 w1_write_8(sl->master, W1_42_COND_READ);
2085                 w1_read_block(sl->master, (u8 *)&rn, 8);
2086                 reg_num = (struct w1_reg_num *) &rn;
2087                 if (reg_num->family == W1_42_FINISHED_BYTE)
2088                         break;
2089                 if (sl->reg_num.id == reg_num->id)
2090                         seq = i;
2091
2092                 w1_write_8(sl->master, W1_42_CHAIN);
2093                 w1_write_8(sl->master, W1_42_CHAIN_DONE);
2094                 w1_write_8(sl->master, W1_42_CHAIN_DONE_INV);
2095                 w1_read_block(sl->master, &ack, sizeof(ack));
2096
2097                 /* check for acknowledgment */
2098                 ack = w1_read_8(sl->master);
2099                 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2100                         goto error;
2101
2102         }
2103
2104         /* Exit from CHAIN state */
2105         if (w1_reset_bus(sl->master))
2106                 goto error;
2107         w1_write_8(sl->master, W1_SKIP_ROM);
2108         w1_write_8(sl->master, W1_42_CHAIN);
2109         w1_write_8(sl->master, W1_42_CHAIN_OFF);
2110         w1_write_8(sl->master, W1_42_CHAIN_OFF_INV);
2111
2112         /* check for acknowledgment */
2113         ack = w1_read_8(sl->master);
2114         if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2115                 goto error;
2116         mutex_unlock(&sl->master->bus_mutex);
2117
2118         c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq);
2119         return PAGE_SIZE - c;
2120 error:
2121         mutex_unlock(&sl->master->bus_mutex);
2122         return -EIO;
2123 }
2124
2125 static int __init w1_therm_init(void)
2126 {
2127         int err, i;
2128
2129         for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
2130                 err = w1_register_family(w1_therm_families[i].f);
2131                 if (err)
2132                         w1_therm_families[i].broken = 1;
2133         }
2134
2135         return 0;
2136 }
2137
2138 static void __exit w1_therm_fini(void)
2139 {
2140         int i;
2141
2142         for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
2143                 if (!w1_therm_families[i].broken)
2144                         w1_unregister_family(w1_therm_families[i].f);
2145 }
2146
2147 module_init(w1_therm_init);
2148 module_exit(w1_therm_fini);
2149
2150 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
2151 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
2152 MODULE_LICENSE("GPL");
2153 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20));
2154 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822));
2155 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20));
2156 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825));
2157 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00));