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 */ 44static int w1_strong_pullup = 1; 45module_param_named(strong_pullup, w1_strong_pullup, int, 0); 46 47/* Counter for devices supporting bulk reading */ 48static 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 mesured */ 67#define MAX_TEMP 125 /* max temperature that can be mesured */ 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 */ 159struct 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 */ 184struct 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 */ 201struct 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 */ 223static 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 */ 232static 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 */ 241static 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 */ 251static 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 */ 259static 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 */ 267static 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 */ 281static 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 */ 293static int trigger_bulk_read(struct w1_master *dev_master); 294 295/* Sysfs interface declaration */ 296 297static ssize_t w1_slave_show(struct device *device, 298 struct device_attribute *attr, char *buf); 299 300static ssize_t w1_slave_store(struct device *device, 301 struct device_attribute *attr, const char *buf, size_t size); 302 303static ssize_t w1_seq_show(struct device *device, 304 struct device_attribute *attr, char *buf); 305 306static ssize_t temperature_show(struct device *device, 307 struct device_attribute *attr, char *buf); 308 309static ssize_t ext_power_show(struct device *device, 310 struct device_attribute *attr, char *buf); 311 312static ssize_t resolution_show(struct device *device, 313 struct device_attribute *attr, char *buf); 314 315static ssize_t resolution_store(struct device *device, 316 struct device_attribute *attr, const char *buf, size_t size); 317 318static ssize_t eeprom_store(struct device *device, 319 struct device_attribute *attr, const char *buf, size_t size); 320 321static ssize_t alarms_store(struct device *device, 322 struct device_attribute *attr, const char *buf, size_t size); 323 324static ssize_t alarms_show(struct device *device, 325 struct device_attribute *attr, char *buf); 326 327static ssize_t therm_bulk_read_store(struct device *device, 328 struct device_attribute *attr, const char *buf, size_t size); 329 330static ssize_t therm_bulk_read_show(struct device *device, 331 struct device_attribute *attr, char *buf); 332 333static ssize_t conv_time_show(struct device *device, 334 struct device_attribute *attr, char *buf); 335 336static ssize_t conv_time_store(struct device *device, 337 struct device_attribute *attr, const char *buf, 338 size_t size); 339 340static ssize_t features_show(struct device *device, 341 struct device_attribute *attr, char *buf); 342 343static ssize_t features_store(struct device *device, 344 struct device_attribute *attr, const char *buf, 345 size_t size); 346/* Attributes declarations */ 347 348static DEVICE_ATTR_RW(w1_slave); 349static DEVICE_ATTR_RO(w1_seq); 350static DEVICE_ATTR_RO(temperature); 351static DEVICE_ATTR_RO(ext_power); 352static DEVICE_ATTR_RW(resolution); 353static DEVICE_ATTR_WO(eeprom); 354static DEVICE_ATTR_RW(alarms); 355static DEVICE_ATTR_RW(conv_time); 356static DEVICE_ATTR_RW(features); 357 358static 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 */ 371static 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 */ 380static void w1_therm_remove_slave(struct w1_slave *sl); 381 382/* Family attributes */ 383 384static 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.attr, 390 &dev_attr_alarms.attr, 391 &dev_attr_conv_time.attr, 392 &dev_attr_features.attr, 393 NULL, 394}; 395 396static 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.attr, 401 &dev_attr_alarms.attr, 402 &dev_attr_conv_time.attr, 403 &dev_attr_features.attr, 404 NULL, 405}; 406 407static 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.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 422ATTRIBUTE_GROUPS(w1_therm); 423ATTRIBUTE_GROUPS(w1_ds18s20); 424ATTRIBUTE_GROUPS(w1_ds28ea00); 425 426#if IS_REACHABLE(CONFIG_HWMON) 427static int w1_read_temp(struct device *dev, u32 attr, int channel, 428 long *val); 429 430static 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 436static 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 447static const u32 w1_temp_config[] = { 448 HWMON_T_INPUT, 449 0 450}; 451 452static const struct hwmon_channel_info w1_temp = { 453 .type = hwmon_temp, 454 .config = w1_temp_config, 455}; 456 457static const struct hwmon_channel_info *w1_info[] = { 458 &w1_temp, 459 NULL 460}; 461 462static const struct hwmon_ops w1_hwmon_ops = { 463 .is_visible = w1_is_visible, 464 .read = w1_read, 465}; 466 467static 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 478static 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 485static 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 492static 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 501static struct w1_family w1_therm_family_DS18S20 = { 502 .fid = W1_THERM_DS18S20, 503 .fops = &w1_ds18s20_fops, 504}; 505 506static struct w1_family w1_therm_family_DS18B20 = { 507 .fid = W1_THERM_DS18B20, 508 .fops = &w1_therm_fops, 509}; 510 511static struct w1_family w1_therm_family_DS1822 = { 512 .fid = W1_THERM_DS1822, 513 .fops = &w1_therm_fops, 514}; 515 516static struct w1_family w1_therm_family_DS28EA00 = { 517 .fid = W1_THERM_DS28EA00, 518 .fops = &w1_ds28ea00_fops, 519}; 520 521static struct w1_family w1_therm_family_DS1825 = { 522 .fid = W1_THERM_DS1825, 523 .fops = &w1_therm_fops, 524}; 525 526/* Device dependent func */ 527 528static 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 566static 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 577static inline int w1_DS18B20_write_data(struct w1_slave *sl, 578 const u8 *data) 579{ 580 return write_scratchpad(sl, data, 3); 581} 582 583static 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 590static 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 637static 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 */ 668static 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 */ 696static 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 721static 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 */ 778static 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 */ 801static 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 */ 826static 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 * support_bulk_read() - 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 */ 842static 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 */ 863static 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 */ 883static 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 */ 906static inline s8 int_to_short(int i) 907{ 908 /* Prepare to cast to short by eliminating out of range values */ 909 i = i > MAX_TEMP ? MAX_TEMP : i; 910 i = i < MIN_TEMP ? MIN_TEMP : i; 911 return (s8) i; 912} 913 914/* Interface Functions */ 915 916static int w1_therm_add_slave(struct w1_slave *sl) 917{ 918 struct w1_therm_family_converter *sl_family_conv; 919 920 /* Allocate memory */ 921 sl->family_data = kzalloc(sizeof(struct w1_therm_family_data), 922 GFP_KERNEL); 923 if (!sl->family_data) 924 return -ENOMEM; 925 926 atomic_set(THERM_REFCNT(sl->family_data), 1); 927 928 /* Get a pointer to the device specific function struct */ 929 sl_family_conv = device_family(sl); 930 if (!sl_family_conv) { 931 kfree(sl->family_data); 932 return -ENODEV; 933 } 934 /* save this pointer to the device structure */ 935 SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv; 936 937 if (bulk_read_support(sl)) { 938 /* 939 * add the sys entry to trigger bulk_read 940 * at master level only the 1st time 941 */ 942 if (!bulk_read_device_counter) { 943 int err = device_create_file(&sl->master->dev, 944 &dev_attr_therm_bulk_read); 945 946 if (err) 947 dev_warn(&sl->dev, 948 "%s: Device has been added, but bulk read is unavailable. err=%d\n", 949 __func__, err); 950 } 951 /* Increment the counter */ 952 bulk_read_device_counter++; 953 } 954 955 /* Getting the power mode of the device {external, parasite} */ 956 SLAVE_POWERMODE(sl) = read_powermode(sl); 957 958 if (SLAVE_POWERMODE(sl) < 0) { 959 /* no error returned as device has been added */ 960 dev_warn(&sl->dev, 961 "%s: Device has been added, but power_mode may be corrupted. err=%d\n", 962 __func__, SLAVE_POWERMODE(sl)); 963 } 964 965 /* Getting the resolution of the device */ 966 if (SLAVE_SPECIFIC_FUNC(sl)->get_resolution) { 967 SLAVE_RESOLUTION(sl) = 968 SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl); 969 if (SLAVE_RESOLUTION(sl) < 0) { 970 /* no error returned as device has been added */ 971 dev_warn(&sl->dev, 972 "%s:Device has been added, but resolution may be corrupted. err=%d\n", 973 __func__, SLAVE_RESOLUTION(sl)); 974 } 975 } 976 977 /* Finally initialize convert_triggered flag */ 978 SLAVE_CONVERT_TRIGGERED(sl) = 0; 979 980 return 0; 981} 982 983static void w1_therm_remove_slave(struct w1_slave *sl) 984{ 985 int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data)); 986 987 if (bulk_read_support(sl)) { 988 bulk_read_device_counter--; 989 /* Delete the entry if no more device support the feature */ 990 if (!bulk_read_device_counter) 991 device_remove_file(&sl->master->dev, 992 &dev_attr_therm_bulk_read); 993 } 994 995 while (refcnt) { 996 msleep(1000); 997 refcnt = atomic_read(THERM_REFCNT(sl->family_data)); 998 } 999 kfree(sl->family_data); 1000 sl->family_data = NULL; 1001} 1002 1003/* Hardware Functions */ 1004 1005/* Safe version of reset_select_slave - avoid using the one in w_io.c */ 1006static int reset_select_slave(struct w1_slave *sl) 1007{ 1008 u8 match[9] = { W1_MATCH_ROM, }; 1009 u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num)); 1010 1011 if (w1_reset_bus(sl->master)) 1012 return -ENODEV; 1013 1014 memcpy(&match[1], &rn, 8); 1015 w1_write_block(sl->master, match, 9); 1016 1017 return 0; 1018} 1019 1020/** 1021 * w1_poll_completion - Poll for operation completion, with timeout 1022 * @dev_master: the device master of the bus 1023 * @tout_ms: timeout in milliseconds 1024 * 1025 * The device is answering 0's while an operation is in progress and 1's after it completes 1026 * Timeout may happen if the previous command was not recognised due to a line noise 1027 * 1028 * Return: 0 - OK, negative error - timeout 1029 */ 1030static int w1_poll_completion(struct w1_master *dev_master, int tout_ms) 1031{ 1032 int i; 1033 1034 for (i = 0; i < tout_ms/W1_POLL_PERIOD; i++) { 1035 /* Delay is before poll, for device to recognize a command */ 1036 msleep(W1_POLL_PERIOD); 1037 1038 /* Compare all 8 bits to mitigate a noise on the bus */ 1039 if (w1_read_8(dev_master) == 0xFF) 1040 break; 1041 } 1042 if (i == tout_ms/W1_POLL_PERIOD) 1043 return -EIO; 1044 1045 return 0; 1046} 1047 1048static int convert_t(struct w1_slave *sl, struct therm_info *info) 1049{ 1050 struct w1_master *dev_master = sl->master; 1051 int max_trying = W1_THERM_MAX_TRY; 1052 int t_conv; 1053 int ret = -ENODEV; 1054 bool strong_pullup; 1055 1056 if (!sl->family_data) 1057 goto error; 1058 1059 strong_pullup = (w1_strong_pullup == 2 || 1060 (!SLAVE_POWERMODE(sl) && 1061 w1_strong_pullup)); 1062 1063 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 1064 dev_warn(&sl->dev, 1065 "%s: Disabling W1_THERM_POLL_COMPLETION in parasite power mode.\n", 1066 __func__); 1067 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION; 1068 } 1069 1070 /* get conversion duration device and id dependent */ 1071 t_conv = conversion_time(sl); 1072 1073 memset(info->rom, 0, sizeof(info->rom)); 1074 1075 /* prevent the slave from going away in sleep */ 1076 atomic_inc(THERM_REFCNT(sl->family_data)); 1077 1078 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1079 ret = -EAGAIN; /* Didn't acquire the mutex */ 1080 goto dec_refcnt; 1081 } 1082 1083 while (max_trying-- && ret) { /* ret should be 0 */ 1084 1085 info->verdict = 0; 1086 info->crc = 0; 1087 /* safe version to select slave */ 1088 if (!reset_select_slave(sl)) { 1089 unsigned long sleep_rem; 1090 1091 /* 750ms strong pullup (or delay) after the convert */ 1092 if (strong_pullup) 1093 w1_next_pullup(dev_master, t_conv); 1094 1095 w1_write_8(dev_master, W1_CONVERT_TEMP); 1096 1097 if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 1098 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); 1099 if (ret) { 1100 dev_dbg(&sl->dev, "%s: Timeout\n", __func__); 1101 goto mt_unlock; 1102 } 1103 mutex_unlock(&dev_master->bus_mutex); 1104 } else if (!strong_pullup) { /*no device need pullup */ 1105 sleep_rem = msleep_interruptible(t_conv); 1106 if (sleep_rem != 0) { 1107 ret = -EINTR; 1108 goto mt_unlock; 1109 } 1110 mutex_unlock(&dev_master->bus_mutex); 1111 } else { /*some device need pullup */ 1112 mutex_unlock(&dev_master->bus_mutex); 1113 sleep_rem = msleep_interruptible(t_conv); 1114 if (sleep_rem != 0) { 1115 ret = -EINTR; 1116 goto dec_refcnt; 1117 } 1118 } 1119 ret = read_scratchpad(sl, info); 1120 1121 /* If enabled, check for conversion success */ 1122 if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) && 1123 (info->rom[6] == 0xC) && 1124 ((info->rom[1] == 0x5 && info->rom[0] == 0x50) || 1125 (info->rom[1] == 0x7 && info->rom[0] == 0xFF)) 1126 ) { 1127 /* Invalid reading (scratchpad byte 6 = 0xC) 1128 * due to insufficient conversion time 1129 * or power failure. 1130 */ 1131 ret = -EIO; 1132 } 1133 1134 goto dec_refcnt; 1135 } 1136 1137 } 1138 1139mt_unlock: 1140 mutex_unlock(&dev_master->bus_mutex); 1141dec_refcnt: 1142 atomic_dec(THERM_REFCNT(sl->family_data)); 1143error: 1144 return ret; 1145} 1146 1147static int conv_time_measure(struct w1_slave *sl, int *conv_time) 1148{ 1149 struct therm_info inf, 1150 *info = &inf; 1151 struct w1_master *dev_master = sl->master; 1152 int max_trying = W1_THERM_MAX_TRY; 1153 int ret = -ENODEV; 1154 bool strong_pullup; 1155 1156 if (!sl->family_data) 1157 goto error; 1158 1159 strong_pullup = (w1_strong_pullup == 2 || 1160 (!SLAVE_POWERMODE(sl) && 1161 w1_strong_pullup)); 1162 1163 if (strong_pullup) { 1164 pr_info("%s: Measure with strong_pullup is not supported.\n", __func__); 1165 return -EINVAL; 1166 } 1167 1168 memset(info->rom, 0, sizeof(info->rom)); 1169 1170 /* prevent the slave from going away in sleep */ 1171 atomic_inc(THERM_REFCNT(sl->family_data)); 1172 1173 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1174 ret = -EAGAIN; /* Didn't acquire the mutex */ 1175 goto dec_refcnt; 1176 } 1177 1178 while (max_trying-- && ret) { /* ret should be 0 */ 1179 info->verdict = 0; 1180 info->crc = 0; 1181 /* safe version to select slave */ 1182 if (!reset_select_slave(sl)) { 1183 int j_start, j_end; 1184 1185 /*no device need pullup */ 1186 w1_write_8(dev_master, W1_CONVERT_TEMP); 1187 1188 j_start = jiffies; 1189 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); 1190 if (ret) { 1191 dev_dbg(&sl->dev, "%s: Timeout\n", __func__); 1192 goto mt_unlock; 1193 } 1194 j_end = jiffies; 1195 /* 1.2x increase for variation and changes over temperature range */ 1196 *conv_time = jiffies_to_msecs(j_end-j_start)*12/10; 1197 pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n", 1198 *conv_time, HZ); 1199 if (*conv_time <= CONV_TIME_MEASURE) { 1200 ret = -EIO; 1201 goto mt_unlock; 1202 } 1203 mutex_unlock(&dev_master->bus_mutex); 1204 ret = read_scratchpad(sl, info); 1205 goto dec_refcnt; 1206 } 1207 1208 } 1209mt_unlock: 1210 mutex_unlock(&dev_master->bus_mutex); 1211dec_refcnt: 1212 atomic_dec(THERM_REFCNT(sl->family_data)); 1213error: 1214 return ret; 1215} 1216 1217static int read_scratchpad(struct w1_slave *sl, struct therm_info *info) 1218{ 1219 struct w1_master *dev_master = sl->master; 1220 int max_trying = W1_THERM_MAX_TRY; 1221 int ret = -ENODEV; 1222 1223 info->verdict = 0; 1224 1225 if (!sl->family_data) 1226 goto error; 1227 1228 memset(info->rom, 0, sizeof(info->rom)); 1229 1230 /* prevent the slave from going away in sleep */ 1231 atomic_inc(THERM_REFCNT(sl->family_data)); 1232 1233 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1234 ret = -EAGAIN; /* Didn't acquire the mutex */ 1235 goto dec_refcnt; 1236 } 1237 1238 while (max_trying-- && ret) { /* ret should be 0 */ 1239 /* safe version to select slave */ 1240 if (!reset_select_slave(sl)) { 1241 u8 nb_bytes_read; 1242 1243 w1_write_8(dev_master, W1_READ_SCRATCHPAD); 1244 1245 nb_bytes_read = w1_read_block(dev_master, info->rom, 9); 1246 if (nb_bytes_read != 9) { 1247 dev_warn(&sl->dev, 1248 "w1_read_block(): returned %u instead of 9.\n", 1249 nb_bytes_read); 1250 ret = -EIO; 1251 } 1252 1253 info->crc = w1_calc_crc8(info->rom, 8); 1254 1255 if (info->rom[8] == info->crc) { 1256 info->verdict = 1; 1257 ret = 0; 1258 } else 1259 ret = -EIO; /* CRC not checked */ 1260 } 1261 1262 } 1263 mutex_unlock(&dev_master->bus_mutex); 1264 1265dec_refcnt: 1266 atomic_dec(THERM_REFCNT(sl->family_data)); 1267error: 1268 return ret; 1269} 1270 1271static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes) 1272{ 1273 struct w1_master *dev_master = sl->master; 1274 int max_trying = W1_THERM_MAX_TRY; 1275 int ret = -ENODEV; 1276 1277 if (!sl->family_data) 1278 goto error; 1279 1280 /* prevent the slave from going away in sleep */ 1281 atomic_inc(THERM_REFCNT(sl->family_data)); 1282 1283 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1284 ret = -EAGAIN; /* Didn't acquire the mutex */ 1285 goto dec_refcnt; 1286 } 1287 1288 while (max_trying-- && ret) { /* ret should be 0 */ 1289 /* safe version to select slave */ 1290 if (!reset_select_slave(sl)) { 1291 w1_write_8(dev_master, W1_WRITE_SCRATCHPAD); 1292 w1_write_block(dev_master, data, nb_bytes); 1293 ret = 0; 1294 } 1295 } 1296 mutex_unlock(&dev_master->bus_mutex); 1297 1298dec_refcnt: 1299 atomic_dec(THERM_REFCNT(sl->family_data)); 1300error: 1301 return ret; 1302} 1303 1304static int copy_scratchpad(struct w1_slave *sl) 1305{ 1306 struct w1_master *dev_master = sl->master; 1307 int max_trying = W1_THERM_MAX_TRY; 1308 int t_write, ret = -ENODEV; 1309 bool strong_pullup; 1310 1311 if (!sl->family_data) 1312 goto error; 1313 1314 t_write = W1_THERM_EEPROM_WRITE_DELAY; 1315 strong_pullup = (w1_strong_pullup == 2 || 1316 (!SLAVE_POWERMODE(sl) && 1317 w1_strong_pullup)); 1318 1319 /* prevent the slave from going away in sleep */ 1320 atomic_inc(THERM_REFCNT(sl->family_data)); 1321 1322 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1323 ret = -EAGAIN; /* Didn't acquire the mutex */ 1324 goto dec_refcnt; 1325 } 1326 1327 while (max_trying-- && ret) { /* ret should be 0 */ 1328 /* safe version to select slave */ 1329 if (!reset_select_slave(sl)) { 1330 unsigned long sleep_rem; 1331 1332 /* 10ms strong pullup (or delay) after the convert */ 1333 if (strong_pullup) 1334 w1_next_pullup(dev_master, t_write); 1335 1336 w1_write_8(dev_master, W1_COPY_SCRATCHPAD); 1337 1338 if (strong_pullup) { 1339 sleep_rem = msleep_interruptible(t_write); 1340 if (sleep_rem != 0) { 1341 ret = -EINTR; 1342 goto mt_unlock; 1343 } 1344 } 1345 ret = 0; 1346 } 1347 1348 } 1349 1350mt_unlock: 1351 mutex_unlock(&dev_master->bus_mutex); 1352dec_refcnt: 1353 atomic_dec(THERM_REFCNT(sl->family_data)); 1354error: 1355 return ret; 1356} 1357 1358static int recall_eeprom(struct w1_slave *sl) 1359{ 1360 struct w1_master *dev_master = sl->master; 1361 int max_trying = W1_THERM_MAX_TRY; 1362 int ret = -ENODEV; 1363 1364 if (!sl->family_data) 1365 goto error; 1366 1367 /* prevent the slave from going away in sleep */ 1368 atomic_inc(THERM_REFCNT(sl->family_data)); 1369 1370 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1371 ret = -EAGAIN; /* Didn't acquire the mutex */ 1372 goto dec_refcnt; 1373 } 1374 1375 while (max_trying-- && ret) { /* ret should be 0 */ 1376 /* safe version to select slave */ 1377 if (!reset_select_slave(sl)) { 1378 1379 w1_write_8(dev_master, W1_RECALL_EEPROM); 1380 ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM); 1381 } 1382 1383 } 1384 1385 mutex_unlock(&dev_master->bus_mutex); 1386 1387dec_refcnt: 1388 atomic_dec(THERM_REFCNT(sl->family_data)); 1389error: 1390 return ret; 1391} 1392 1393static int read_powermode(struct w1_slave *sl) 1394{ 1395 struct w1_master *dev_master = sl->master; 1396 int max_trying = W1_THERM_MAX_TRY; 1397 int ret = -ENODEV; 1398 1399 if (!sl->family_data) 1400 goto error; 1401 1402 /* prevent the slave from going away in sleep */ 1403 atomic_inc(THERM_REFCNT(sl->family_data)); 1404 1405 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1406 ret = -EAGAIN; /* Didn't acquire the mutex */ 1407 goto dec_refcnt; 1408 } 1409 1410 while ((max_trying--) && (ret < 0)) { 1411 /* safe version to select slave */ 1412 if (!reset_select_slave(sl)) { 1413 w1_write_8(dev_master, W1_READ_PSUPPLY); 1414 /* 1415 * Emit a read time slot and read only one bit, 1416 * 1 is externally powered, 1417 * 0 is parasite powered 1418 */ 1419 ret = w1_touch_bit(dev_master, 1); 1420 /* ret should be either 1 either 0 */ 1421 } 1422 } 1423 mutex_unlock(&dev_master->bus_mutex); 1424 1425dec_refcnt: 1426 atomic_dec(THERM_REFCNT(sl->family_data)); 1427error: 1428 return ret; 1429} 1430 1431static int trigger_bulk_read(struct w1_master *dev_master) 1432{ 1433 struct w1_slave *sl = NULL; /* used to iterate through slaves */ 1434 int max_trying = W1_THERM_MAX_TRY; 1435 int t_conv = 0; 1436 int ret = -ENODEV; 1437 bool strong_pullup = false; 1438 1439 /* 1440 * Check whether there are parasite powered device on the bus, 1441 * and compute duration of conversion for these devices 1442 * so we can apply a strong pullup if required 1443 */ 1444 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1445 if (!sl->family_data) 1446 goto error; 1447 if (bulk_read_support(sl)) { 1448 int t_cur = conversion_time(sl); 1449 1450 t_conv = t_cur > t_conv ? t_cur : t_conv; 1451 strong_pullup = strong_pullup || 1452 (w1_strong_pullup == 2 || 1453 (!SLAVE_POWERMODE(sl) && 1454 w1_strong_pullup)); 1455 } 1456 } 1457 1458 /* 1459 * t_conv is the max conversion time required on the bus 1460 * If its 0, no device support the bulk read feature 1461 */ 1462 if (!t_conv) 1463 goto error; 1464 1465 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1466 ret = -EAGAIN; /* Didn't acquire the mutex */ 1467 goto error; 1468 } 1469 1470 while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */ 1471 1472 if (!w1_reset_bus(dev_master)) { /* Just reset the bus */ 1473 unsigned long sleep_rem; 1474 1475 w1_write_8(dev_master, W1_SKIP_ROM); 1476 1477 if (strong_pullup) /* Apply pullup if required */ 1478 w1_next_pullup(dev_master, t_conv); 1479 1480 w1_write_8(dev_master, W1_CONVERT_TEMP); 1481 1482 /* set a flag to instruct that converT pending */ 1483 list_for_each_entry(sl, 1484 &dev_master->slist, w1_slave_entry) { 1485 if (bulk_read_support(sl)) 1486 SLAVE_CONVERT_TRIGGERED(sl) = -1; 1487 } 1488 1489 if (strong_pullup) { /* some device need pullup */ 1490 sleep_rem = msleep_interruptible(t_conv); 1491 if (sleep_rem != 0) { 1492 ret = -EINTR; 1493 goto mt_unlock; 1494 } 1495 mutex_unlock(&dev_master->bus_mutex); 1496 } else { 1497 mutex_unlock(&dev_master->bus_mutex); 1498 sleep_rem = msleep_interruptible(t_conv); 1499 if (sleep_rem != 0) { 1500 ret = -EINTR; 1501 goto set_flag; 1502 } 1503 } 1504 ret = 0; 1505 goto set_flag; 1506 } 1507 } 1508 1509mt_unlock: 1510 mutex_unlock(&dev_master->bus_mutex); 1511set_flag: 1512 /* set a flag to register convsersion is done */ 1513 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1514 if (bulk_read_support(sl)) 1515 SLAVE_CONVERT_TRIGGERED(sl) = 1; 1516 } 1517error: 1518 return ret; 1519} 1520 1521/* Sysfs Interface definition */ 1522 1523static ssize_t w1_slave_show(struct device *device, 1524 struct device_attribute *attr, char *buf) 1525{ 1526 struct w1_slave *sl = dev_to_w1_slave(device); 1527 struct therm_info info; 1528 u8 *family_data = sl->family_data; 1529 int ret, i; 1530 ssize_t c = PAGE_SIZE; 1531 1532 if (bulk_read_support(sl)) { 1533 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) { 1534 dev_dbg(device, 1535 "%s: Conversion in progress, retry later\n", 1536 __func__); 1537 return 0; 1538 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) { 1539 /* A bulk read has been issued, read the device RAM */ 1540 ret = read_scratchpad(sl, &info); 1541 SLAVE_CONVERT_TRIGGERED(sl) = 0; 1542 } else 1543 ret = convert_t(sl, &info); 1544 } else 1545 ret = convert_t(sl, &info); 1546 1547 if (ret < 0) { 1548 dev_dbg(device, 1549 "%s: Temperature data may be corrupted. err=%d\n", 1550 __func__, ret); 1551 return 0; 1552 } 1553 1554 for (i = 0; i < 9; ++i) 1555 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]); 1556 c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n", 1557 info.crc, (info.verdict) ? "YES" : "NO"); 1558 1559 if (info.verdict) 1560 memcpy(family_data, info.rom, sizeof(info.rom)); 1561 else 1562 dev_warn(device, "%s:Read failed CRC check\n", __func__); 1563 1564 for (i = 0; i < 9; ++i) 1565 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", 1566 ((u8 *)family_data)[i]); 1567 1568 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n", 1569 temperature_from_RAM(sl, info.rom)); 1570 1571 ret = PAGE_SIZE - c; 1572 return ret; 1573} 1574 1575static ssize_t w1_slave_store(struct device *device, 1576 struct device_attribute *attr, const char *buf, 1577 size_t size) 1578{ 1579 int val, ret = 0; 1580 struct w1_slave *sl = dev_to_w1_slave(device); 1581 1582 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */ 1583 1584 if (ret) { /* conversion error */ 1585 dev_info(device, 1586 "%s: conversion error. err= %d\n", __func__, ret); 1587 return size; /* return size to avoid call back again */ 1588 } 1589 1590 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1591 dev_info(device, 1592 "%s: Device not supported by the driver\n", __func__); 1593 return size; /* No device family */ 1594 } 1595 1596 if (val == 0) /* val=0 : trigger a EEPROM save */ 1597 ret = copy_scratchpad(sl); 1598 else { 1599 if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution) 1600 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val); 1601 } 1602 1603 if (ret) { 1604 dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret); 1605 /* Propagate error to userspace */ 1606 return ret; 1607 } 1608 SLAVE_RESOLUTION(sl) = val; 1609 /* Reset the conversion time to default - it depends on resolution */ 1610 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT; 1611 1612 return size; /* always return size to avoid infinite calling */ 1613} 1614 1615static ssize_t temperature_show(struct device *device, 1616 struct device_attribute *attr, char *buf) 1617{ 1618 struct w1_slave *sl = dev_to_w1_slave(device); 1619 struct therm_info info; 1620 int ret = 0; 1621 1622 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1623 dev_info(device, 1624 "%s: Device not supported by the driver\n", __func__); 1625 return 0; /* No device family */ 1626 } 1627 1628 if (bulk_read_support(sl)) { 1629 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) { 1630 dev_dbg(device, 1631 "%s: Conversion in progress, retry later\n", 1632 __func__); 1633 return 0; 1634 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) { 1635 /* A bulk read has been issued, read the device RAM */ 1636 ret = read_scratchpad(sl, &info); 1637 SLAVE_CONVERT_TRIGGERED(sl) = 0; 1638 } else 1639 ret = convert_t(sl, &info); 1640 } else 1641 ret = convert_t(sl, &info); 1642 1643 if (ret < 0) { 1644 dev_dbg(device, 1645 "%s: Temperature data may be corrupted. err=%d\n", 1646 __func__, ret); 1647 return 0; 1648 } 1649 1650 return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom)); 1651} 1652 1653static ssize_t ext_power_show(struct device *device, 1654 struct device_attribute *attr, char *buf) 1655{ 1656 struct w1_slave *sl = dev_to_w1_slave(device); 1657 1658 if (!sl->family_data) { 1659 dev_info(device, 1660 "%s: Device not supported by the driver\n", __func__); 1661 return 0; /* No device family */ 1662 } 1663 1664 /* Getting the power mode of the device {external, parasite} */ 1665 SLAVE_POWERMODE(sl) = read_powermode(sl); 1666 1667 if (SLAVE_POWERMODE(sl) < 0) { 1668 dev_dbg(device, 1669 "%s: Power_mode may be corrupted. err=%d\n", 1670 __func__, SLAVE_POWERMODE(sl)); 1671 } 1672 return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl)); 1673} 1674 1675static ssize_t resolution_show(struct device *device, 1676 struct device_attribute *attr, char *buf) 1677{ 1678 struct w1_slave *sl = dev_to_w1_slave(device); 1679 1680 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1681 dev_info(device, 1682 "%s: Device not supported by the driver\n", __func__); 1683 return 0; /* No device family */ 1684 } 1685 1686 /* get the correct function depending on the device */ 1687 SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl); 1688 if (SLAVE_RESOLUTION(sl) < 0) { 1689 dev_dbg(device, 1690 "%s: Resolution may be corrupted. err=%d\n", 1691 __func__, SLAVE_RESOLUTION(sl)); 1692 } 1693 1694 return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl)); 1695} 1696 1697static ssize_t resolution_store(struct device *device, 1698 struct device_attribute *attr, const char *buf, size_t size) 1699{ 1700 struct w1_slave *sl = dev_to_w1_slave(device); 1701 int val; 1702 int ret = 0; 1703 1704 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */ 1705 1706 if (ret) { /* conversion error */ 1707 dev_info(device, 1708 "%s: conversion error. err= %d\n", __func__, ret); 1709 return size; /* return size to avoid call back again */ 1710 } 1711 1712 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1713 dev_info(device, 1714 "%s: Device not supported by the driver\n", __func__); 1715 return size; /* No device family */ 1716 } 1717 1718 /* 1719 * Don't deal with the val enterd by user, 1720 * only device knows what is correct or not 1721 */ 1722 1723 /* get the correct function depending on the device */ 1724 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val); 1725 1726 if (ret) 1727 return ret; 1728 1729 SLAVE_RESOLUTION(sl) = val; 1730 /* Reset the conversion time to default because it depends on resolution */ 1731 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT; 1732 1733 return size; 1734} 1735 1736static ssize_t eeprom_store(struct device *device, 1737 struct device_attribute *attr, const char *buf, size_t size) 1738{ 1739 struct w1_slave *sl = dev_to_w1_slave(device); 1740 int ret = -EINVAL; /* Invalid argument */ 1741 1742 if (size == sizeof(EEPROM_CMD_WRITE)) { 1743 if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1)) 1744 ret = copy_scratchpad(sl); 1745 } else if (size == sizeof(EEPROM_CMD_READ)) { 1746 if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1)) 1747 ret = recall_eeprom(sl); 1748 } 1749 1750 if (ret) 1751 dev_info(device, "%s: error in process %d\n", __func__, ret); 1752 1753 return size; 1754} 1755 1756static ssize_t alarms_show(struct device *device, 1757 struct device_attribute *attr, char *buf) 1758{ 1759 struct w1_slave *sl = dev_to_w1_slave(device); 1760 int ret; 1761 s8 th = 0, tl = 0; 1762 struct therm_info scratchpad; 1763 1764 ret = read_scratchpad(sl, &scratchpad); 1765 1766 if (!ret) { 1767 th = scratchpad.rom[2]; /* TH is byte 2 */ 1768 tl = scratchpad.rom[3]; /* TL is byte 3 */ 1769 } else { 1770 dev_info(device, 1771 "%s: error reading alarms register %d\n", 1772 __func__, ret); 1773 } 1774 1775 return sprintf(buf, "%hd %hd\n", tl, th); 1776} 1777 1778static ssize_t alarms_store(struct device *device, 1779 struct device_attribute *attr, const char *buf, size_t size) 1780{ 1781 struct w1_slave *sl = dev_to_w1_slave(device); 1782 struct therm_info info; 1783 u8 new_config_register[3]; /* array of data to be written */ 1784 int temp, ret; 1785 char *token = NULL; 1786 s8 tl, th, tt; /* 1 byte per value + temp ring order */ 1787 char *p_args, *orig; 1788 1789 p_args = orig = kmalloc(size, GFP_KERNEL); 1790 /* Safe string copys as buf is const */ 1791 if (!p_args) { 1792 dev_warn(device, 1793 "%s: error unable to allocate memory %d\n", 1794 __func__, -ENOMEM); 1795 return size; 1796 } 1797 strcpy(p_args, buf); 1798 1799 /* Split string using space char */ 1800 token = strsep(&p_args, " "); 1801 1802 if (!token) { 1803 dev_info(device, 1804 "%s: error parsing args %d\n", __func__, -EINVAL); 1805 goto free_m; 1806 } 1807 1808 /* Convert 1st entry to int */ 1809 ret = kstrtoint (token, 10, &temp); 1810 if (ret) { 1811 dev_info(device, 1812 "%s: error parsing args %d\n", __func__, ret); 1813 goto free_m; 1814 } 1815 1816 tl = int_to_short(temp); 1817 1818 /* Split string using space char */ 1819 token = strsep(&p_args, " "); 1820 if (!token) { 1821 dev_info(device, 1822 "%s: error parsing args %d\n", __func__, -EINVAL); 1823 goto free_m; 1824 } 1825 /* Convert 2nd entry to int */ 1826 ret = kstrtoint (token, 10, &temp); 1827 if (ret) { 1828 dev_info(device, 1829 "%s: error parsing args %d\n", __func__, ret); 1830 goto free_m; 1831 } 1832 1833 /* Prepare to cast to short by eliminating out of range values */ 1834 th = int_to_short(temp); 1835 1836 /* Reorder if required th and tl */ 1837 if (tl > th) { 1838 tt = tl; tl = th; th = tt; 1839 } 1840 1841 /* 1842 * Read the scratchpad to change only the required bits 1843 * (th : byte 2 - tl: byte 3) 1844 */ 1845 ret = read_scratchpad(sl, &info); 1846 if (!ret) { 1847 new_config_register[0] = th; /* Byte 2 */ 1848 new_config_register[1] = tl; /* Byte 3 */ 1849 new_config_register[2] = info.rom[4];/* Byte 4 */ 1850 } else { 1851 dev_info(device, 1852 "%s: error reading from the slave device %d\n", 1853 __func__, ret); 1854 goto free_m; 1855 } 1856 1857 /* Write data in the device RAM */ 1858 if (!SLAVE_SPECIFIC_FUNC(sl)) { 1859 dev_info(device, 1860 "%s: Device not supported by the driver %d\n", 1861 __func__, -ENODEV); 1862 goto free_m; 1863 } 1864 1865 ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register); 1866 if (ret) 1867 dev_info(device, 1868 "%s: error writing to the slave device %d\n", 1869 __func__, ret); 1870 1871free_m: 1872 /* free allocated memory */ 1873 kfree(orig); 1874 1875 return size; 1876} 1877 1878static ssize_t therm_bulk_read_store(struct device *device, 1879 struct device_attribute *attr, const char *buf, size_t size) 1880{ 1881 struct w1_master *dev_master = dev_to_w1_master(device); 1882 int ret = -EINVAL; /* Invalid argument */ 1883 1884 if (size == sizeof(BULK_TRIGGER_CMD)) 1885 if (!strncmp(buf, BULK_TRIGGER_CMD, 1886 sizeof(BULK_TRIGGER_CMD)-1)) 1887 ret = trigger_bulk_read(dev_master); 1888 1889 if (ret) 1890 dev_info(device, 1891 "%s: unable to trigger a bulk read on the bus. err=%d\n", 1892 __func__, ret); 1893 1894 return size; 1895} 1896 1897static ssize_t therm_bulk_read_show(struct device *device, 1898 struct device_attribute *attr, char *buf) 1899{ 1900 struct w1_master *dev_master = dev_to_w1_master(device); 1901 struct w1_slave *sl = NULL; 1902 int ret = 0; 1903 1904 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1905 if (sl->family_data) { 1906 if (bulk_read_support(sl)) { 1907 if (SLAVE_CONVERT_TRIGGERED(sl) == -1) { 1908 ret = -1; 1909 goto show_result; 1910 } 1911 if (SLAVE_CONVERT_TRIGGERED(sl) == 1) 1912 /* continue to check other slaves */ 1913 ret = 1; 1914 } 1915 } 1916 } 1917show_result: 1918 return sprintf(buf, "%d\n", ret); 1919} 1920 1921static ssize_t conv_time_show(struct device *device, 1922 struct device_attribute *attr, char *buf) 1923{ 1924 struct w1_slave *sl = dev_to_w1_slave(device); 1925 1926 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1927 dev_info(device, 1928 "%s: Device is not supported by the driver\n", __func__); 1929 return 0; /* No device family */ 1930 } 1931 return sprintf(buf, "%d\n", conversion_time(sl)); 1932} 1933 1934static ssize_t conv_time_store(struct device *device, 1935 struct device_attribute *attr, const char *buf, size_t size) 1936{ 1937 int val, ret = 0; 1938 struct w1_slave *sl = dev_to_w1_slave(device); 1939 1940 if (kstrtoint(buf, 10, &val)) /* converting user entry to int */ 1941 return -EINVAL; 1942 1943 if (check_family_data(sl)) 1944 return -ENODEV; 1945 1946 if (val != CONV_TIME_MEASURE) { 1947 if (val >= CONV_TIME_DEFAULT) 1948 SLAVE_CONV_TIME_OVERRIDE(sl) = val; 1949 else 1950 return -EINVAL; 1951 1952 } else { 1953 int conv_time; 1954 1955 ret = conv_time_measure(sl, &conv_time); 1956 if (ret) 1957 return -EIO; 1958 SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time; 1959 } 1960 return size; 1961} 1962 1963static ssize_t features_show(struct device *device, 1964 struct device_attribute *attr, char *buf) 1965{ 1966 struct w1_slave *sl = dev_to_w1_slave(device); 1967 1968 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1969 dev_info(device, 1970 "%s: Device not supported by the driver\n", __func__); 1971 return 0; /* No device family */ 1972 } 1973 return sprintf(buf, "%u\n", SLAVE_FEATURES(sl)); 1974} 1975 1976static ssize_t features_store(struct device *device, 1977 struct device_attribute *attr, const char *buf, size_t size) 1978{ 1979 int val, ret = 0; 1980 bool strong_pullup; 1981 struct w1_slave *sl = dev_to_w1_slave(device); 1982 1983 ret = kstrtouint(buf, 10, &val); /* converting user entry to int */ 1984 if (ret) 1985 return -EINVAL; /* invalid number */ 1986 1987 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1988 dev_info(device, "%s: Device not supported by the driver\n", __func__); 1989 return -ENODEV; 1990 } 1991 1992 if ((val & W1_THERM_FEATURES_MASK) != val) 1993 return -EINVAL; 1994 1995 SLAVE_FEATURES(sl) = val; 1996 1997 strong_pullup = (w1_strong_pullup == 2 || 1998 (!SLAVE_POWERMODE(sl) && 1999 w1_strong_pullup)); 2000 2001 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 2002 dev_warn(&sl->dev, 2003 "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n", 2004 __func__); 2005 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION; 2006 } 2007 2008 return size; 2009} 2010 2011#if IS_REACHABLE(CONFIG_HWMON) 2012static int w1_read_temp(struct device *device, u32 attr, int channel, 2013 long *val) 2014{ 2015 struct w1_slave *sl = dev_get_drvdata(device); 2016 struct therm_info info; 2017 int ret; 2018 2019 switch (attr) { 2020 case hwmon_temp_input: 2021 ret = convert_t(sl, &info); 2022 if (ret) 2023 return ret; 2024 2025 if (!info.verdict) { 2026 ret = -EIO; 2027 return ret; 2028 } 2029 2030 *val = temperature_from_RAM(sl, info.rom); 2031 ret = 0; 2032 break; 2033 default: 2034 ret = -EOPNOTSUPP; 2035 break; 2036 } 2037 2038 return ret; 2039} 2040#endif 2041 2042#define W1_42_CHAIN 0x99 2043#define W1_42_CHAIN_OFF 0x3C 2044#define W1_42_CHAIN_OFF_INV 0xC3 2045#define W1_42_CHAIN_ON 0x5A 2046#define W1_42_CHAIN_ON_INV 0xA5 2047#define W1_42_CHAIN_DONE 0x96 2048#define W1_42_CHAIN_DONE_INV 0x69 2049#define W1_42_COND_READ 0x0F 2050#define W1_42_SUCCESS_CONFIRM_BYTE 0xAA 2051#define W1_42_FINISHED_BYTE 0xFF 2052static ssize_t w1_seq_show(struct device *device, 2053 struct device_attribute *attr, char *buf) 2054{ 2055 struct w1_slave *sl = dev_to_w1_slave(device); 2056 ssize_t c = PAGE_SIZE; 2057 int rv; 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 rv = 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 if (w1_reset_bus(sl->master)) 2093 goto error; 2094 2095 /* Put the device into chain DONE state */ 2096 w1_write_8(sl->master, W1_MATCH_ROM); 2097 w1_write_block(sl->master, (u8 *)&rn, 8); 2098 w1_write_8(sl->master, W1_42_CHAIN); 2099 w1_write_8(sl->master, W1_42_CHAIN_DONE); 2100 w1_write_8(sl->master, W1_42_CHAIN_DONE_INV); 2101 2102 /* check for acknowledgment */ 2103 ack = w1_read_8(sl->master); 2104 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2105 goto error; 2106 } 2107 2108 /* Exit from CHAIN state */ 2109 if (w1_reset_bus(sl->master)) 2110 goto error; 2111 w1_write_8(sl->master, W1_SKIP_ROM); 2112 w1_write_8(sl->master, W1_42_CHAIN); 2113 w1_write_8(sl->master, W1_42_CHAIN_OFF); 2114 w1_write_8(sl->master, W1_42_CHAIN_OFF_INV); 2115 2116 /* check for acknowledgment */ 2117 ack = w1_read_8(sl->master); 2118 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2119 goto error; 2120 mutex_unlock(&sl->master->bus_mutex); 2121 2122 c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq); 2123 return PAGE_SIZE - c; 2124error: 2125 mutex_unlock(&sl->master->bus_mutex); 2126 return -EIO; 2127} 2128 2129static int __init w1_therm_init(void) 2130{ 2131 int err, i; 2132 2133 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) { 2134 err = w1_register_family(w1_therm_families[i].f); 2135 if (err) 2136 w1_therm_families[i].broken = 1; 2137 } 2138 2139 return 0; 2140} 2141 2142static void __exit w1_therm_fini(void) 2143{ 2144 int i; 2145 2146 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) 2147 if (!w1_therm_families[i].broken) 2148 w1_unregister_family(w1_therm_families[i].f); 2149} 2150 2151module_init(w1_therm_init); 2152module_exit(w1_therm_fini); 2153 2154MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); 2155MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family."); 2156MODULE_LICENSE("GPL"); 2157MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20)); 2158MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822)); 2159MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20)); 2160MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825)); 2161MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00)); 2162