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 * 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 */ 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, tt; /* 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 tt = tl; tl = th; th = tt; 1841 } 1842 1843 /* 1844 * Read the scratchpad to change only the required bits 1845 * (th : byte 2 - tl: byte 3) 1846 */ 1847 ret = read_scratchpad(sl, &info); 1848 if (!ret) { 1849 new_config_register[0] = th; /* Byte 2 */ 1850 new_config_register[1] = tl; /* Byte 3 */ 1851 new_config_register[2] = info.rom[4];/* Byte 4 */ 1852 } else { 1853 dev_info(device, 1854 "%s: error reading from the slave device %d\n", 1855 __func__, ret); 1856 goto free_m; 1857 } 1858 1859 /* Write data in the device RAM */ 1860 if (!SLAVE_SPECIFIC_FUNC(sl)) { 1861 dev_info(device, 1862 "%s: Device not supported by the driver %d\n", 1863 __func__, -ENODEV); 1864 goto free_m; 1865 } 1866 1867 ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register); 1868 if (ret) 1869 dev_info(device, 1870 "%s: error writing to the slave device %d\n", 1871 __func__, ret); 1872 1873 free_m: 1874 /* free allocated memory */ 1875 kfree(orig); 1876 1877 return size; 1878 } 1879 1880 static ssize_t therm_bulk_read_store(struct device *device, 1881 struct device_attribute *attr, const char *buf, size_t size) 1882 { 1883 struct w1_master *dev_master = dev_to_w1_master(device); 1884 int ret = -EINVAL; /* Invalid argument */ 1885 1886 if (size == sizeof(BULK_TRIGGER_CMD)) 1887 if (!strncmp(buf, BULK_TRIGGER_CMD, 1888 sizeof(BULK_TRIGGER_CMD)-1)) 1889 ret = trigger_bulk_read(dev_master); 1890 1891 if (ret) 1892 dev_info(device, 1893 "%s: unable to trigger a bulk read on the bus. err=%d\n", 1894 __func__, ret); 1895 1896 return size; 1897 } 1898 1899 static ssize_t therm_bulk_read_show(struct device *device, 1900 struct device_attribute *attr, char *buf) 1901 { 1902 struct w1_master *dev_master = dev_to_w1_master(device); 1903 struct w1_slave *sl = NULL; 1904 int ret = 0; 1905 1906 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1907 if (sl->family_data) { 1908 if (bulk_read_support(sl)) { 1909 if (SLAVE_CONVERT_TRIGGERED(sl) == -1) { 1910 ret = -1; 1911 goto show_result; 1912 } 1913 if (SLAVE_CONVERT_TRIGGERED(sl) == 1) 1914 /* continue to check other slaves */ 1915 ret = 1; 1916 } 1917 } 1918 } 1919 show_result: 1920 return sprintf(buf, "%d\n", ret); 1921 } 1922 1923 static ssize_t conv_time_show(struct device *device, 1924 struct device_attribute *attr, char *buf) 1925 { 1926 struct w1_slave *sl = dev_to_w1_slave(device); 1927 1928 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1929 dev_info(device, 1930 "%s: Device is not supported by the driver\n", __func__); 1931 return 0; /* No device family */ 1932 } 1933 return sprintf(buf, "%d\n", conversion_time(sl)); 1934 } 1935 1936 static ssize_t conv_time_store(struct device *device, 1937 struct device_attribute *attr, const char *buf, size_t size) 1938 { 1939 int val, ret = 0; 1940 struct w1_slave *sl = dev_to_w1_slave(device); 1941 1942 if (kstrtoint(buf, 10, &val)) /* converting user entry to int */ 1943 return -EINVAL; 1944 1945 if (check_family_data(sl)) 1946 return -ENODEV; 1947 1948 if (val != CONV_TIME_MEASURE) { 1949 if (val >= CONV_TIME_DEFAULT) 1950 SLAVE_CONV_TIME_OVERRIDE(sl) = val; 1951 else 1952 return -EINVAL; 1953 1954 } else { 1955 int conv_time; 1956 1957 ret = conv_time_measure(sl, &conv_time); 1958 if (ret) 1959 return -EIO; 1960 SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time; 1961 } 1962 return size; 1963 } 1964 1965 static ssize_t features_show(struct device *device, 1966 struct device_attribute *attr, char *buf) 1967 { 1968 struct w1_slave *sl = dev_to_w1_slave(device); 1969 1970 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1971 dev_info(device, 1972 "%s: Device not supported by the driver\n", __func__); 1973 return 0; /* No device family */ 1974 } 1975 return sprintf(buf, "%u\n", SLAVE_FEATURES(sl)); 1976 } 1977 1978 static ssize_t features_store(struct device *device, 1979 struct device_attribute *attr, const char *buf, size_t size) 1980 { 1981 int val, ret = 0; 1982 bool strong_pullup; 1983 struct w1_slave *sl = dev_to_w1_slave(device); 1984 1985 ret = kstrtouint(buf, 10, &val); /* converting user entry to int */ 1986 if (ret) 1987 return -EINVAL; /* invalid number */ 1988 1989 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1990 dev_info(device, "%s: Device not supported by the driver\n", __func__); 1991 return -ENODEV; 1992 } 1993 1994 if ((val & W1_THERM_FEATURES_MASK) != val) 1995 return -EINVAL; 1996 1997 SLAVE_FEATURES(sl) = val; 1998 1999 strong_pullup = (w1_strong_pullup == 2 || 2000 (!SLAVE_POWERMODE(sl) && 2001 w1_strong_pullup)); 2002 2003 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 2004 dev_warn(&sl->dev, 2005 "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n", 2006 __func__); 2007 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION; 2008 } 2009 2010 return size; 2011 } 2012 2013 #if IS_REACHABLE(CONFIG_HWMON) 2014 static int w1_read_temp(struct device *device, u32 attr, int channel, 2015 long *val) 2016 { 2017 struct w1_slave *sl = dev_get_drvdata(device); 2018 struct therm_info info; 2019 int ret; 2020 2021 switch (attr) { 2022 case hwmon_temp_input: 2023 ret = convert_t(sl, &info); 2024 if (ret) 2025 return ret; 2026 2027 if (!info.verdict) { 2028 ret = -EIO; 2029 return ret; 2030 } 2031 2032 *val = temperature_from_RAM(sl, info.rom); 2033 ret = 0; 2034 break; 2035 default: 2036 ret = -EOPNOTSUPP; 2037 break; 2038 } 2039 2040 return ret; 2041 } 2042 #endif 2043 2044 #define W1_42_CHAIN 0x99 2045 #define W1_42_CHAIN_OFF 0x3C 2046 #define W1_42_CHAIN_OFF_INV 0xC3 2047 #define W1_42_CHAIN_ON 0x5A 2048 #define W1_42_CHAIN_ON_INV 0xA5 2049 #define W1_42_CHAIN_DONE 0x96 2050 #define W1_42_CHAIN_DONE_INV 0x69 2051 #define W1_42_COND_READ 0x0F 2052 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA 2053 #define W1_42_FINISHED_BYTE 0xFF 2054 static ssize_t w1_seq_show(struct device *device, 2055 struct device_attribute *attr, char *buf) 2056 { 2057 struct w1_slave *sl = dev_to_w1_slave(device); 2058 ssize_t c = PAGE_SIZE; 2059 int rv; 2060 int i; 2061 u8 ack; 2062 u64 rn; 2063 struct w1_reg_num *reg_num; 2064 int seq = 0; 2065 2066 mutex_lock(&sl->master->bus_mutex); 2067 /* Place all devices in CHAIN state */ 2068 if (w1_reset_bus(sl->master)) 2069 goto error; 2070 w1_write_8(sl->master, W1_SKIP_ROM); 2071 w1_write_8(sl->master, W1_42_CHAIN); 2072 w1_write_8(sl->master, W1_42_CHAIN_ON); 2073 w1_write_8(sl->master, W1_42_CHAIN_ON_INV); 2074 msleep(sl->master->pullup_duration); 2075 2076 /* check for acknowledgment */ 2077 ack = w1_read_8(sl->master); 2078 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2079 goto error; 2080 2081 /* In case the bus fails to send 0xFF, limit */ 2082 for (i = 0; i <= 64; i++) { 2083 if (w1_reset_bus(sl->master)) 2084 goto error; 2085 2086 w1_write_8(sl->master, W1_42_COND_READ); 2087 rv = w1_read_block(sl->master, (u8 *)&rn, 8); 2088 reg_num = (struct w1_reg_num *) &rn; 2089 if (reg_num->family == W1_42_FINISHED_BYTE) 2090 break; 2091 if (sl->reg_num.id == reg_num->id) 2092 seq = i; 2093 2094 w1_write_8(sl->master, W1_42_CHAIN); 2095 w1_write_8(sl->master, W1_42_CHAIN_DONE); 2096 w1_write_8(sl->master, W1_42_CHAIN_DONE_INV); 2097 w1_read_block(sl->master, &ack, sizeof(ack)); 2098 2099 /* check for acknowledgment */ 2100 ack = w1_read_8(sl->master); 2101 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2102 goto error; 2103 2104 } 2105 2106 /* Exit from CHAIN state */ 2107 if (w1_reset_bus(sl->master)) 2108 goto error; 2109 w1_write_8(sl->master, W1_SKIP_ROM); 2110 w1_write_8(sl->master, W1_42_CHAIN); 2111 w1_write_8(sl->master, W1_42_CHAIN_OFF); 2112 w1_write_8(sl->master, W1_42_CHAIN_OFF_INV); 2113 2114 /* check for acknowledgment */ 2115 ack = w1_read_8(sl->master); 2116 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2117 goto error; 2118 mutex_unlock(&sl->master->bus_mutex); 2119 2120 c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq); 2121 return PAGE_SIZE - c; 2122 error: 2123 mutex_unlock(&sl->master->bus_mutex); 2124 return -EIO; 2125 } 2126 2127 static int __init w1_therm_init(void) 2128 { 2129 int err, i; 2130 2131 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) { 2132 err = w1_register_family(w1_therm_families[i].f); 2133 if (err) 2134 w1_therm_families[i].broken = 1; 2135 } 2136 2137 return 0; 2138 } 2139 2140 static void __exit w1_therm_fini(void) 2141 { 2142 int i; 2143 2144 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) 2145 if (!w1_therm_families[i].broken) 2146 w1_unregister_family(w1_therm_families[i].f); 2147 } 2148 2149 module_init(w1_therm_init); 2150 module_exit(w1_therm_fini); 2151 2152 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); 2153 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family."); 2154 MODULE_LICENSE("GPL"); 2155 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20)); 2156 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822)); 2157 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20)); 2158 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825)); 2159 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00)); 2160