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 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 */ 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 = i > MAX_TEMP ? MAX_TEMP : i; 910 i = i < MIN_TEMP ? MIN_TEMP : i; 911 return (s8) i; 912 } 913 914 /* Interface Functions */ 915 916 static 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 } 982 983 static 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 */ 1006 static 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 */ 1030 static 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 1048 static 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 (strong_pullup) { /*some device need pullup */ 1098 sleep_rem = msleep_interruptible(t_conv); 1099 if (sleep_rem != 0) { 1100 ret = -EINTR; 1101 goto mt_unlock; 1102 } 1103 mutex_unlock(&dev_master->bus_mutex); 1104 } else { /*no device need pullup */ 1105 if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 1106 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); 1107 if (ret) { 1108 dev_dbg(&sl->dev, "%s: Timeout\n", __func__); 1109 goto mt_unlock; 1110 } 1111 mutex_unlock(&dev_master->bus_mutex); 1112 } else { 1113 /* Fixed delay */ 1114 mutex_unlock(&dev_master->bus_mutex); 1115 sleep_rem = msleep_interruptible(t_conv); 1116 if (sleep_rem != 0) { 1117 ret = -EINTR; 1118 goto dec_refcnt; 1119 } 1120 } 1121 } 1122 ret = read_scratchpad(sl, info); 1123 1124 /* If enabled, check for conversion success */ 1125 if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) && 1126 (info->rom[6] == 0xC) && 1127 ((info->rom[1] == 0x5 && info->rom[0] == 0x50) || 1128 (info->rom[1] == 0x7 && info->rom[0] == 0xFF)) 1129 ) { 1130 /* Invalid reading (scratchpad byte 6 = 0xC) 1131 * due to insufficient conversion time 1132 * or power failure. 1133 */ 1134 ret = -EIO; 1135 } 1136 1137 goto dec_refcnt; 1138 } 1139 1140 } 1141 1142 mt_unlock: 1143 mutex_unlock(&dev_master->bus_mutex); 1144 dec_refcnt: 1145 atomic_dec(THERM_REFCNT(sl->family_data)); 1146 error: 1147 return ret; 1148 } 1149 1150 static int conv_time_measure(struct w1_slave *sl, int *conv_time) 1151 { 1152 struct therm_info inf, 1153 *info = &inf; 1154 struct w1_master *dev_master = sl->master; 1155 int max_trying = W1_THERM_MAX_TRY; 1156 int ret = -ENODEV; 1157 bool strong_pullup; 1158 1159 if (!sl->family_data) 1160 goto error; 1161 1162 strong_pullup = (w1_strong_pullup == 2 || 1163 (!SLAVE_POWERMODE(sl) && 1164 w1_strong_pullup)); 1165 1166 if (strong_pullup) { 1167 pr_info("%s: Measure with strong_pullup is not supported.\n", __func__); 1168 return -EINVAL; 1169 } 1170 1171 memset(info->rom, 0, sizeof(info->rom)); 1172 1173 /* prevent the slave from going away in sleep */ 1174 atomic_inc(THERM_REFCNT(sl->family_data)); 1175 1176 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1177 ret = -EAGAIN; /* Didn't acquire the mutex */ 1178 goto dec_refcnt; 1179 } 1180 1181 while (max_trying-- && ret) { /* ret should be 0 */ 1182 info->verdict = 0; 1183 info->crc = 0; 1184 /* safe version to select slave */ 1185 if (!reset_select_slave(sl)) { 1186 int j_start, j_end; 1187 1188 /*no device need pullup */ 1189 w1_write_8(dev_master, W1_CONVERT_TEMP); 1190 1191 j_start = jiffies; 1192 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); 1193 if (ret) { 1194 dev_dbg(&sl->dev, "%s: Timeout\n", __func__); 1195 goto mt_unlock; 1196 } 1197 j_end = jiffies; 1198 /* 1.2x increase for variation and changes over temperature range */ 1199 *conv_time = jiffies_to_msecs(j_end-j_start)*12/10; 1200 pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n", 1201 *conv_time, HZ); 1202 if (*conv_time <= CONV_TIME_MEASURE) { 1203 ret = -EIO; 1204 goto mt_unlock; 1205 } 1206 mutex_unlock(&dev_master->bus_mutex); 1207 ret = read_scratchpad(sl, info); 1208 goto dec_refcnt; 1209 } 1210 1211 } 1212 mt_unlock: 1213 mutex_unlock(&dev_master->bus_mutex); 1214 dec_refcnt: 1215 atomic_dec(THERM_REFCNT(sl->family_data)); 1216 error: 1217 return ret; 1218 } 1219 1220 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info) 1221 { 1222 struct w1_master *dev_master = sl->master; 1223 int max_trying = W1_THERM_MAX_TRY; 1224 int ret = -ENODEV; 1225 1226 info->verdict = 0; 1227 1228 if (!sl->family_data) 1229 goto error; 1230 1231 memset(info->rom, 0, sizeof(info->rom)); 1232 1233 /* prevent the slave from going away in sleep */ 1234 atomic_inc(THERM_REFCNT(sl->family_data)); 1235 1236 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1237 ret = -EAGAIN; /* Didn't acquire the mutex */ 1238 goto dec_refcnt; 1239 } 1240 1241 while (max_trying-- && ret) { /* ret should be 0 */ 1242 /* safe version to select slave */ 1243 if (!reset_select_slave(sl)) { 1244 u8 nb_bytes_read; 1245 1246 w1_write_8(dev_master, W1_READ_SCRATCHPAD); 1247 1248 nb_bytes_read = w1_read_block(dev_master, info->rom, 9); 1249 if (nb_bytes_read != 9) { 1250 dev_warn(&sl->dev, 1251 "w1_read_block(): returned %u instead of 9.\n", 1252 nb_bytes_read); 1253 ret = -EIO; 1254 } 1255 1256 info->crc = w1_calc_crc8(info->rom, 8); 1257 1258 if (info->rom[8] == info->crc) { 1259 info->verdict = 1; 1260 ret = 0; 1261 } else 1262 ret = -EIO; /* CRC not checked */ 1263 } 1264 1265 } 1266 mutex_unlock(&dev_master->bus_mutex); 1267 1268 dec_refcnt: 1269 atomic_dec(THERM_REFCNT(sl->family_data)); 1270 error: 1271 return ret; 1272 } 1273 1274 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes) 1275 { 1276 struct w1_master *dev_master = sl->master; 1277 int max_trying = W1_THERM_MAX_TRY; 1278 int ret = -ENODEV; 1279 1280 if (!sl->family_data) 1281 goto error; 1282 1283 /* prevent the slave from going away in sleep */ 1284 atomic_inc(THERM_REFCNT(sl->family_data)); 1285 1286 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1287 ret = -EAGAIN; /* Didn't acquire the mutex */ 1288 goto dec_refcnt; 1289 } 1290 1291 while (max_trying-- && ret) { /* ret should be 0 */ 1292 /* safe version to select slave */ 1293 if (!reset_select_slave(sl)) { 1294 w1_write_8(dev_master, W1_WRITE_SCRATCHPAD); 1295 w1_write_block(dev_master, data, nb_bytes); 1296 ret = 0; 1297 } 1298 } 1299 mutex_unlock(&dev_master->bus_mutex); 1300 1301 dec_refcnt: 1302 atomic_dec(THERM_REFCNT(sl->family_data)); 1303 error: 1304 return ret; 1305 } 1306 1307 static int copy_scratchpad(struct w1_slave *sl) 1308 { 1309 struct w1_master *dev_master = sl->master; 1310 int max_trying = W1_THERM_MAX_TRY; 1311 int t_write, ret = -ENODEV; 1312 bool strong_pullup; 1313 1314 if (!sl->family_data) 1315 goto error; 1316 1317 t_write = W1_THERM_EEPROM_WRITE_DELAY; 1318 strong_pullup = (w1_strong_pullup == 2 || 1319 (!SLAVE_POWERMODE(sl) && 1320 w1_strong_pullup)); 1321 1322 /* prevent the slave from going away in sleep */ 1323 atomic_inc(THERM_REFCNT(sl->family_data)); 1324 1325 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1326 ret = -EAGAIN; /* Didn't acquire the mutex */ 1327 goto dec_refcnt; 1328 } 1329 1330 while (max_trying-- && ret) { /* ret should be 0 */ 1331 /* safe version to select slave */ 1332 if (!reset_select_slave(sl)) { 1333 unsigned long sleep_rem; 1334 1335 /* 10ms strong pullup (or delay) after the convert */ 1336 if (strong_pullup) 1337 w1_next_pullup(dev_master, t_write); 1338 1339 w1_write_8(dev_master, W1_COPY_SCRATCHPAD); 1340 1341 if (strong_pullup) { 1342 sleep_rem = msleep_interruptible(t_write); 1343 if (sleep_rem != 0) { 1344 ret = -EINTR; 1345 goto mt_unlock; 1346 } 1347 } 1348 ret = 0; 1349 } 1350 1351 } 1352 1353 mt_unlock: 1354 mutex_unlock(&dev_master->bus_mutex); 1355 dec_refcnt: 1356 atomic_dec(THERM_REFCNT(sl->family_data)); 1357 error: 1358 return ret; 1359 } 1360 1361 static int recall_eeprom(struct w1_slave *sl) 1362 { 1363 struct w1_master *dev_master = sl->master; 1364 int max_trying = W1_THERM_MAX_TRY; 1365 int ret = -ENODEV; 1366 1367 if (!sl->family_data) 1368 goto error; 1369 1370 /* prevent the slave from going away in sleep */ 1371 atomic_inc(THERM_REFCNT(sl->family_data)); 1372 1373 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1374 ret = -EAGAIN; /* Didn't acquire the mutex */ 1375 goto dec_refcnt; 1376 } 1377 1378 while (max_trying-- && ret) { /* ret should be 0 */ 1379 /* safe version to select slave */ 1380 if (!reset_select_slave(sl)) { 1381 1382 w1_write_8(dev_master, W1_RECALL_EEPROM); 1383 ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM); 1384 } 1385 1386 } 1387 1388 mutex_unlock(&dev_master->bus_mutex); 1389 1390 dec_refcnt: 1391 atomic_dec(THERM_REFCNT(sl->family_data)); 1392 error: 1393 return ret; 1394 } 1395 1396 static int read_powermode(struct w1_slave *sl) 1397 { 1398 struct w1_master *dev_master = sl->master; 1399 int max_trying = W1_THERM_MAX_TRY; 1400 int ret = -ENODEV; 1401 1402 if (!sl->family_data) 1403 goto error; 1404 1405 /* prevent the slave from going away in sleep */ 1406 atomic_inc(THERM_REFCNT(sl->family_data)); 1407 1408 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1409 ret = -EAGAIN; /* Didn't acquire the mutex */ 1410 goto dec_refcnt; 1411 } 1412 1413 while ((max_trying--) && (ret < 0)) { 1414 /* safe version to select slave */ 1415 if (!reset_select_slave(sl)) { 1416 w1_write_8(dev_master, W1_READ_PSUPPLY); 1417 /* 1418 * Emit a read time slot and read only one bit, 1419 * 1 is externally powered, 1420 * 0 is parasite powered 1421 */ 1422 ret = w1_touch_bit(dev_master, 1); 1423 /* ret should be either 1 either 0 */ 1424 } 1425 } 1426 mutex_unlock(&dev_master->bus_mutex); 1427 1428 dec_refcnt: 1429 atomic_dec(THERM_REFCNT(sl->family_data)); 1430 error: 1431 return ret; 1432 } 1433 1434 static int trigger_bulk_read(struct w1_master *dev_master) 1435 { 1436 struct w1_slave *sl = NULL; /* used to iterate through slaves */ 1437 int max_trying = W1_THERM_MAX_TRY; 1438 int t_conv = 0; 1439 int ret = -ENODEV; 1440 bool strong_pullup = false; 1441 1442 /* 1443 * Check whether there are parasite powered device on the bus, 1444 * and compute duration of conversion for these devices 1445 * so we can apply a strong pullup if required 1446 */ 1447 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1448 if (!sl->family_data) 1449 goto error; 1450 if (bulk_read_support(sl)) { 1451 int t_cur = conversion_time(sl); 1452 1453 t_conv = t_cur > t_conv ? t_cur : t_conv; 1454 strong_pullup = strong_pullup || 1455 (w1_strong_pullup == 2 || 1456 (!SLAVE_POWERMODE(sl) && 1457 w1_strong_pullup)); 1458 } 1459 } 1460 1461 /* 1462 * t_conv is the max conversion time required on the bus 1463 * If its 0, no device support the bulk read feature 1464 */ 1465 if (!t_conv) 1466 goto error; 1467 1468 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1469 ret = -EAGAIN; /* Didn't acquire the mutex */ 1470 goto error; 1471 } 1472 1473 while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */ 1474 1475 if (!w1_reset_bus(dev_master)) { /* Just reset the bus */ 1476 unsigned long sleep_rem; 1477 1478 w1_write_8(dev_master, W1_SKIP_ROM); 1479 1480 if (strong_pullup) /* Apply pullup if required */ 1481 w1_next_pullup(dev_master, t_conv); 1482 1483 w1_write_8(dev_master, W1_CONVERT_TEMP); 1484 1485 /* set a flag to instruct that converT pending */ 1486 list_for_each_entry(sl, 1487 &dev_master->slist, w1_slave_entry) { 1488 if (bulk_read_support(sl)) 1489 SLAVE_CONVERT_TRIGGERED(sl) = -1; 1490 } 1491 1492 if (strong_pullup) { /* some device need pullup */ 1493 sleep_rem = msleep_interruptible(t_conv); 1494 if (sleep_rem != 0) { 1495 ret = -EINTR; 1496 goto mt_unlock; 1497 } 1498 mutex_unlock(&dev_master->bus_mutex); 1499 } else { 1500 mutex_unlock(&dev_master->bus_mutex); 1501 sleep_rem = msleep_interruptible(t_conv); 1502 if (sleep_rem != 0) { 1503 ret = -EINTR; 1504 goto set_flag; 1505 } 1506 } 1507 ret = 0; 1508 goto set_flag; 1509 } 1510 } 1511 1512 mt_unlock: 1513 mutex_unlock(&dev_master->bus_mutex); 1514 set_flag: 1515 /* set a flag to register convsersion is done */ 1516 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1517 if (bulk_read_support(sl)) 1518 SLAVE_CONVERT_TRIGGERED(sl) = 1; 1519 } 1520 error: 1521 return ret; 1522 } 1523 1524 /* Sysfs Interface definition */ 1525 1526 static ssize_t w1_slave_show(struct device *device, 1527 struct device_attribute *attr, char *buf) 1528 { 1529 struct w1_slave *sl = dev_to_w1_slave(device); 1530 struct therm_info info; 1531 u8 *family_data = sl->family_data; 1532 int ret, i; 1533 ssize_t c = PAGE_SIZE; 1534 1535 if (bulk_read_support(sl)) { 1536 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) { 1537 dev_dbg(device, 1538 "%s: Conversion in progress, retry later\n", 1539 __func__); 1540 return 0; 1541 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) { 1542 /* A bulk read has been issued, read the device RAM */ 1543 ret = read_scratchpad(sl, &info); 1544 SLAVE_CONVERT_TRIGGERED(sl) = 0; 1545 } else 1546 ret = convert_t(sl, &info); 1547 } else 1548 ret = convert_t(sl, &info); 1549 1550 if (ret < 0) { 1551 dev_dbg(device, 1552 "%s: Temperature data may be corrupted. err=%d\n", 1553 __func__, ret); 1554 return 0; 1555 } 1556 1557 for (i = 0; i < 9; ++i) 1558 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]); 1559 c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n", 1560 info.crc, (info.verdict) ? "YES" : "NO"); 1561 1562 if (info.verdict) 1563 memcpy(family_data, info.rom, sizeof(info.rom)); 1564 else 1565 dev_warn(device, "%s:Read failed CRC check\n", __func__); 1566 1567 for (i = 0; i < 9; ++i) 1568 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", 1569 ((u8 *)family_data)[i]); 1570 1571 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n", 1572 temperature_from_RAM(sl, info.rom)); 1573 1574 ret = PAGE_SIZE - c; 1575 return ret; 1576 } 1577 1578 static ssize_t w1_slave_store(struct device *device, 1579 struct device_attribute *attr, const char *buf, 1580 size_t size) 1581 { 1582 int val, ret = 0; 1583 struct w1_slave *sl = dev_to_w1_slave(device); 1584 1585 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */ 1586 1587 if (ret) { /* conversion error */ 1588 dev_info(device, 1589 "%s: conversion error. err= %d\n", __func__, ret); 1590 return size; /* return size to avoid call back again */ 1591 } 1592 1593 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1594 dev_info(device, 1595 "%s: Device not supported by the driver\n", __func__); 1596 return size; /* No device family */ 1597 } 1598 1599 if (val == 0) /* val=0 : trigger a EEPROM save */ 1600 ret = copy_scratchpad(sl); 1601 else { 1602 if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution) 1603 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val); 1604 } 1605 1606 if (ret) { 1607 dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret); 1608 /* Propagate error to userspace */ 1609 return ret; 1610 } 1611 SLAVE_RESOLUTION(sl) = val; 1612 /* Reset the conversion time to default - it depends on resolution */ 1613 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT; 1614 1615 return size; /* always return size to avoid infinite calling */ 1616 } 1617 1618 static ssize_t temperature_show(struct device *device, 1619 struct device_attribute *attr, char *buf) 1620 { 1621 struct w1_slave *sl = dev_to_w1_slave(device); 1622 struct therm_info info; 1623 int ret = 0; 1624 1625 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1626 dev_info(device, 1627 "%s: Device not supported by the driver\n", __func__); 1628 return 0; /* No device family */ 1629 } 1630 1631 if (bulk_read_support(sl)) { 1632 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) { 1633 dev_dbg(device, 1634 "%s: Conversion in progress, retry later\n", 1635 __func__); 1636 return 0; 1637 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) { 1638 /* A bulk read has been issued, read the device RAM */ 1639 ret = read_scratchpad(sl, &info); 1640 SLAVE_CONVERT_TRIGGERED(sl) = 0; 1641 } else 1642 ret = convert_t(sl, &info); 1643 } else 1644 ret = convert_t(sl, &info); 1645 1646 if (ret < 0) { 1647 dev_dbg(device, 1648 "%s: Temperature data may be corrupted. err=%d\n", 1649 __func__, ret); 1650 return 0; 1651 } 1652 1653 return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom)); 1654 } 1655 1656 static ssize_t ext_power_show(struct device *device, 1657 struct device_attribute *attr, char *buf) 1658 { 1659 struct w1_slave *sl = dev_to_w1_slave(device); 1660 1661 if (!sl->family_data) { 1662 dev_info(device, 1663 "%s: Device not supported by the driver\n", __func__); 1664 return 0; /* No device family */ 1665 } 1666 1667 /* Getting the power mode of the device {external, parasite} */ 1668 SLAVE_POWERMODE(sl) = read_powermode(sl); 1669 1670 if (SLAVE_POWERMODE(sl) < 0) { 1671 dev_dbg(device, 1672 "%s: Power_mode may be corrupted. err=%d\n", 1673 __func__, SLAVE_POWERMODE(sl)); 1674 } 1675 return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl)); 1676 } 1677 1678 static ssize_t resolution_show(struct device *device, 1679 struct device_attribute *attr, char *buf) 1680 { 1681 struct w1_slave *sl = dev_to_w1_slave(device); 1682 1683 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1684 dev_info(device, 1685 "%s: Device not supported by the driver\n", __func__); 1686 return 0; /* No device family */ 1687 } 1688 1689 /* get the correct function depending on the device */ 1690 SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl); 1691 if (SLAVE_RESOLUTION(sl) < 0) { 1692 dev_dbg(device, 1693 "%s: Resolution may be corrupted. err=%d\n", 1694 __func__, SLAVE_RESOLUTION(sl)); 1695 } 1696 1697 return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl)); 1698 } 1699 1700 static ssize_t resolution_store(struct device *device, 1701 struct device_attribute *attr, const char *buf, size_t size) 1702 { 1703 struct w1_slave *sl = dev_to_w1_slave(device); 1704 int val; 1705 int ret = 0; 1706 1707 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */ 1708 1709 if (ret) { /* conversion error */ 1710 dev_info(device, 1711 "%s: conversion error. err= %d\n", __func__, ret); 1712 return size; /* return size to avoid call back again */ 1713 } 1714 1715 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1716 dev_info(device, 1717 "%s: Device not supported by the driver\n", __func__); 1718 return size; /* No device family */ 1719 } 1720 1721 /* 1722 * Don't deal with the val enterd by user, 1723 * only device knows what is correct or not 1724 */ 1725 1726 /* get the correct function depending on the device */ 1727 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val); 1728 1729 if (ret) 1730 return ret; 1731 1732 SLAVE_RESOLUTION(sl) = val; 1733 /* Reset the conversion time to default because it depends on resolution */ 1734 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT; 1735 1736 return size; 1737 } 1738 1739 static ssize_t eeprom_cmd_store(struct device *device, 1740 struct device_attribute *attr, const char *buf, size_t size) 1741 { 1742 struct w1_slave *sl = dev_to_w1_slave(device); 1743 int ret = -EINVAL; /* Invalid argument */ 1744 1745 if (size == sizeof(EEPROM_CMD_WRITE)) { 1746 if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1)) 1747 ret = copy_scratchpad(sl); 1748 } else if (size == sizeof(EEPROM_CMD_READ)) { 1749 if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1)) 1750 ret = recall_eeprom(sl); 1751 } 1752 1753 if (ret) 1754 dev_info(device, "%s: error in process %d\n", __func__, ret); 1755 1756 return size; 1757 } 1758 1759 static ssize_t alarms_show(struct device *device, 1760 struct device_attribute *attr, char *buf) 1761 { 1762 struct w1_slave *sl = dev_to_w1_slave(device); 1763 int ret; 1764 s8 th = 0, tl = 0; 1765 struct therm_info scratchpad; 1766 1767 ret = read_scratchpad(sl, &scratchpad); 1768 1769 if (!ret) { 1770 th = scratchpad.rom[2]; /* TH is byte 2 */ 1771 tl = scratchpad.rom[3]; /* TL is byte 3 */ 1772 } else { 1773 dev_info(device, 1774 "%s: error reading alarms register %d\n", 1775 __func__, ret); 1776 } 1777 1778 return sprintf(buf, "%hd %hd\n", tl, th); 1779 } 1780 1781 static ssize_t alarms_store(struct device *device, 1782 struct device_attribute *attr, const char *buf, size_t size) 1783 { 1784 struct w1_slave *sl = dev_to_w1_slave(device); 1785 struct therm_info info; 1786 u8 new_config_register[3]; /* array of data to be written */ 1787 int temp, ret; 1788 char *token = NULL; 1789 s8 tl, th, tt; /* 1 byte per value + temp ring order */ 1790 char *p_args, *orig; 1791 1792 p_args = orig = kmalloc(size, GFP_KERNEL); 1793 /* Safe string copys as buf is const */ 1794 if (!p_args) { 1795 dev_warn(device, 1796 "%s: error unable to allocate memory %d\n", 1797 __func__, -ENOMEM); 1798 return size; 1799 } 1800 strcpy(p_args, buf); 1801 1802 /* Split string using space char */ 1803 token = strsep(&p_args, " "); 1804 1805 if (!token) { 1806 dev_info(device, 1807 "%s: error parsing args %d\n", __func__, -EINVAL); 1808 goto free_m; 1809 } 1810 1811 /* Convert 1st entry to int */ 1812 ret = kstrtoint (token, 10, &temp); 1813 if (ret) { 1814 dev_info(device, 1815 "%s: error parsing args %d\n", __func__, ret); 1816 goto free_m; 1817 } 1818 1819 tl = int_to_short(temp); 1820 1821 /* Split string using space char */ 1822 token = strsep(&p_args, " "); 1823 if (!token) { 1824 dev_info(device, 1825 "%s: error parsing args %d\n", __func__, -EINVAL); 1826 goto free_m; 1827 } 1828 /* Convert 2nd entry to int */ 1829 ret = kstrtoint (token, 10, &temp); 1830 if (ret) { 1831 dev_info(device, 1832 "%s: error parsing args %d\n", __func__, ret); 1833 goto free_m; 1834 } 1835 1836 /* Prepare to cast to short by eliminating out of range values */ 1837 th = int_to_short(temp); 1838 1839 /* Reorder if required th and tl */ 1840 if (tl > th) { 1841 tt = tl; tl = th; th = tt; 1842 } 1843 1844 /* 1845 * Read the scratchpad to change only the required bits 1846 * (th : byte 2 - tl: byte 3) 1847 */ 1848 ret = read_scratchpad(sl, &info); 1849 if (!ret) { 1850 new_config_register[0] = th; /* Byte 2 */ 1851 new_config_register[1] = tl; /* Byte 3 */ 1852 new_config_register[2] = info.rom[4];/* Byte 4 */ 1853 } else { 1854 dev_info(device, 1855 "%s: error reading from the slave device %d\n", 1856 __func__, ret); 1857 goto free_m; 1858 } 1859 1860 /* Write data in the device RAM */ 1861 if (!SLAVE_SPECIFIC_FUNC(sl)) { 1862 dev_info(device, 1863 "%s: Device not supported by the driver %d\n", 1864 __func__, -ENODEV); 1865 goto free_m; 1866 } 1867 1868 ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register); 1869 if (ret) 1870 dev_info(device, 1871 "%s: error writing to the slave device %d\n", 1872 __func__, ret); 1873 1874 free_m: 1875 /* free allocated memory */ 1876 kfree(orig); 1877 1878 return size; 1879 } 1880 1881 static ssize_t therm_bulk_read_store(struct device *device, 1882 struct device_attribute *attr, const char *buf, size_t size) 1883 { 1884 struct w1_master *dev_master = dev_to_w1_master(device); 1885 int ret = -EINVAL; /* Invalid argument */ 1886 1887 if (size == sizeof(BULK_TRIGGER_CMD)) 1888 if (!strncmp(buf, BULK_TRIGGER_CMD, 1889 sizeof(BULK_TRIGGER_CMD)-1)) 1890 ret = trigger_bulk_read(dev_master); 1891 1892 if (ret) 1893 dev_info(device, 1894 "%s: unable to trigger a bulk read on the bus. err=%d\n", 1895 __func__, ret); 1896 1897 return size; 1898 } 1899 1900 static ssize_t therm_bulk_read_show(struct device *device, 1901 struct device_attribute *attr, char *buf) 1902 { 1903 struct w1_master *dev_master = dev_to_w1_master(device); 1904 struct w1_slave *sl = NULL; 1905 int ret = 0; 1906 1907 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1908 if (sl->family_data) { 1909 if (bulk_read_support(sl)) { 1910 if (SLAVE_CONVERT_TRIGGERED(sl) == -1) { 1911 ret = -1; 1912 goto show_result; 1913 } 1914 if (SLAVE_CONVERT_TRIGGERED(sl) == 1) 1915 /* continue to check other slaves */ 1916 ret = 1; 1917 } 1918 } 1919 } 1920 show_result: 1921 return sprintf(buf, "%d\n", ret); 1922 } 1923 1924 static ssize_t conv_time_show(struct device *device, 1925 struct device_attribute *attr, char *buf) 1926 { 1927 struct w1_slave *sl = dev_to_w1_slave(device); 1928 1929 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1930 dev_info(device, 1931 "%s: Device is not supported by the driver\n", __func__); 1932 return 0; /* No device family */ 1933 } 1934 return sprintf(buf, "%d\n", conversion_time(sl)); 1935 } 1936 1937 static ssize_t conv_time_store(struct device *device, 1938 struct device_attribute *attr, const char *buf, size_t size) 1939 { 1940 int val, ret = 0; 1941 struct w1_slave *sl = dev_to_w1_slave(device); 1942 1943 if (kstrtoint(buf, 10, &val)) /* converting user entry to int */ 1944 return -EINVAL; 1945 1946 if (check_family_data(sl)) 1947 return -ENODEV; 1948 1949 if (val != CONV_TIME_MEASURE) { 1950 if (val >= CONV_TIME_DEFAULT) 1951 SLAVE_CONV_TIME_OVERRIDE(sl) = val; 1952 else 1953 return -EINVAL; 1954 1955 } else { 1956 int conv_time; 1957 1958 ret = conv_time_measure(sl, &conv_time); 1959 if (ret) 1960 return -EIO; 1961 SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time; 1962 } 1963 return size; 1964 } 1965 1966 static ssize_t features_show(struct device *device, 1967 struct device_attribute *attr, char *buf) 1968 { 1969 struct w1_slave *sl = dev_to_w1_slave(device); 1970 1971 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1972 dev_info(device, 1973 "%s: Device not supported by the driver\n", __func__); 1974 return 0; /* No device family */ 1975 } 1976 return sprintf(buf, "%u\n", SLAVE_FEATURES(sl)); 1977 } 1978 1979 static ssize_t features_store(struct device *device, 1980 struct device_attribute *attr, const char *buf, size_t size) 1981 { 1982 int val, ret = 0; 1983 bool strong_pullup; 1984 struct w1_slave *sl = dev_to_w1_slave(device); 1985 1986 ret = kstrtouint(buf, 10, &val); /* converting user entry to int */ 1987 if (ret) 1988 return -EINVAL; /* invalid number */ 1989 1990 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1991 dev_info(device, "%s: Device not supported by the driver\n", __func__); 1992 return -ENODEV; 1993 } 1994 1995 if ((val & W1_THERM_FEATURES_MASK) != val) 1996 return -EINVAL; 1997 1998 SLAVE_FEATURES(sl) = val; 1999 2000 strong_pullup = (w1_strong_pullup == 2 || 2001 (!SLAVE_POWERMODE(sl) && 2002 w1_strong_pullup)); 2003 2004 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 2005 dev_warn(&sl->dev, 2006 "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n", 2007 __func__); 2008 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION; 2009 } 2010 2011 return size; 2012 } 2013 2014 #if IS_REACHABLE(CONFIG_HWMON) 2015 static int w1_read_temp(struct device *device, u32 attr, int channel, 2016 long *val) 2017 { 2018 struct w1_slave *sl = dev_get_drvdata(device); 2019 struct therm_info info; 2020 int ret; 2021 2022 switch (attr) { 2023 case hwmon_temp_input: 2024 ret = convert_t(sl, &info); 2025 if (ret) 2026 return ret; 2027 2028 if (!info.verdict) { 2029 ret = -EIO; 2030 return ret; 2031 } 2032 2033 *val = temperature_from_RAM(sl, info.rom); 2034 ret = 0; 2035 break; 2036 default: 2037 ret = -EOPNOTSUPP; 2038 break; 2039 } 2040 2041 return ret; 2042 } 2043 #endif 2044 2045 #define W1_42_CHAIN 0x99 2046 #define W1_42_CHAIN_OFF 0x3C 2047 #define W1_42_CHAIN_OFF_INV 0xC3 2048 #define W1_42_CHAIN_ON 0x5A 2049 #define W1_42_CHAIN_ON_INV 0xA5 2050 #define W1_42_CHAIN_DONE 0x96 2051 #define W1_42_CHAIN_DONE_INV 0x69 2052 #define W1_42_COND_READ 0x0F 2053 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA 2054 #define W1_42_FINISHED_BYTE 0xFF 2055 static ssize_t w1_seq_show(struct device *device, 2056 struct device_attribute *attr, char *buf) 2057 { 2058 struct w1_slave *sl = dev_to_w1_slave(device); 2059 ssize_t c = PAGE_SIZE; 2060 int rv; 2061 int i; 2062 u8 ack; 2063 u64 rn; 2064 struct w1_reg_num *reg_num; 2065 int seq = 0; 2066 2067 mutex_lock(&sl->master->bus_mutex); 2068 /* Place all devices in CHAIN state */ 2069 if (w1_reset_bus(sl->master)) 2070 goto error; 2071 w1_write_8(sl->master, W1_SKIP_ROM); 2072 w1_write_8(sl->master, W1_42_CHAIN); 2073 w1_write_8(sl->master, W1_42_CHAIN_ON); 2074 w1_write_8(sl->master, W1_42_CHAIN_ON_INV); 2075 msleep(sl->master->pullup_duration); 2076 2077 /* check for acknowledgment */ 2078 ack = w1_read_8(sl->master); 2079 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2080 goto error; 2081 2082 /* In case the bus fails to send 0xFF, limit */ 2083 for (i = 0; i <= 64; i++) { 2084 if (w1_reset_bus(sl->master)) 2085 goto error; 2086 2087 w1_write_8(sl->master, W1_42_COND_READ); 2088 rv = w1_read_block(sl->master, (u8 *)&rn, 8); 2089 reg_num = (struct w1_reg_num *) &rn; 2090 if (reg_num->family == W1_42_FINISHED_BYTE) 2091 break; 2092 if (sl->reg_num.id == reg_num->id) 2093 seq = i; 2094 2095 w1_write_8(sl->master, W1_42_CHAIN); 2096 w1_write_8(sl->master, W1_42_CHAIN_DONE); 2097 w1_write_8(sl->master, W1_42_CHAIN_DONE_INV); 2098 w1_read_block(sl->master, &ack, sizeof(ack)); 2099 2100 /* check for acknowledgment */ 2101 ack = w1_read_8(sl->master); 2102 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2103 goto error; 2104 2105 } 2106 2107 /* Exit from CHAIN state */ 2108 if (w1_reset_bus(sl->master)) 2109 goto error; 2110 w1_write_8(sl->master, W1_SKIP_ROM); 2111 w1_write_8(sl->master, W1_42_CHAIN); 2112 w1_write_8(sl->master, W1_42_CHAIN_OFF); 2113 w1_write_8(sl->master, W1_42_CHAIN_OFF_INV); 2114 2115 /* check for acknowledgment */ 2116 ack = w1_read_8(sl->master); 2117 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2118 goto error; 2119 mutex_unlock(&sl->master->bus_mutex); 2120 2121 c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq); 2122 return PAGE_SIZE - c; 2123 error: 2124 mutex_unlock(&sl->master->bus_mutex); 2125 return -EIO; 2126 } 2127 2128 static int __init w1_therm_init(void) 2129 { 2130 int err, i; 2131 2132 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) { 2133 err = w1_register_family(w1_therm_families[i].f); 2134 if (err) 2135 w1_therm_families[i].broken = 1; 2136 } 2137 2138 return 0; 2139 } 2140 2141 static void __exit w1_therm_fini(void) 2142 { 2143 int i; 2144 2145 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) 2146 if (!w1_therm_families[i].broken) 2147 w1_unregister_family(w1_therm_families[i].f); 2148 } 2149 2150 module_init(w1_therm_init); 2151 module_exit(w1_therm_fini); 2152 2153 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); 2154 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family."); 2155 MODULE_LICENSE("GPL"); 2156 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20)); 2157 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822)); 2158 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20)); 2159 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825)); 2160 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00)); 2161