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 int t; 671 u32 bv; 672 673 /* Config register bit R2 = 1 - GX20MH01 in 13 or 14 bit resolution mode */ 674 if (rom[4] & 0x80) { 675 /* Signed 16-bit value to unsigned, cpu order */ 676 bv = le16_to_cpup((__le16 *)rom); 677 678 /* Insert two temperature bits from config register */ 679 /* Avoid arithmetic shift of signed value */ 680 bv = (bv << 2) | (rom[4] & 3); 681 682 t = (int) sign_extend32(bv, 17); /* Degrees, lowest bit is 2^-6 */ 683 return (t*1000)/64; /* Millidegrees */ 684 } 685 686 t = (int)le16_to_cpup((__le16 *)rom); 687 return t*1000/16; 688 } 689 690 691 692 /** 693 * w1_DS18S20_convert_temp() - temperature computation for DS18S20 694 * @rom: data read from device RAM (8 data bytes + 1 CRC byte) 695 * 696 * Can be called for any DS18S20 compliant device. 697 * 698 * Return: value in millidegrees Celsius. 699 */ 700 static inline int w1_DS18S20_convert_temp(u8 rom[9]) 701 { 702 int t, h; 703 704 if (!rom[7]) { 705 pr_debug("%s: Invalid argument for conversion\n", __func__); 706 return 0; 707 } 708 709 if (rom[1] == 0) 710 t = ((s32)rom[0] >> 1)*1000; 711 else 712 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1); 713 714 t -= 250; 715 h = 1000*((s32)rom[7] - (s32)rom[6]); 716 h /= (s32)rom[7]; 717 t += h; 718 719 return t; 720 } 721 722 /* Device capability description */ 723 /* GX20MH01 device shares family number and structure with DS18B20 */ 724 725 static struct w1_therm_family_converter w1_therm_families[] = { 726 { 727 .f = &w1_therm_family_DS18S20, 728 .convert = w1_DS18S20_convert_temp, 729 .get_conversion_time = w1_DS18S20_convert_time, 730 .set_resolution = NULL, /* no config register */ 731 .get_resolution = NULL, /* no config register */ 732 .write_data = w1_DS18S20_write_data, 733 .bulk_read = true 734 }, 735 { 736 .f = &w1_therm_family_DS1822, 737 .convert = w1_DS18B20_convert_temp, 738 .get_conversion_time = w1_DS18B20_convert_time, 739 .set_resolution = w1_DS18B20_set_resolution, 740 .get_resolution = w1_DS18B20_get_resolution, 741 .write_data = w1_DS18B20_write_data, 742 .bulk_read = true 743 }, 744 { 745 /* Also used for GX20MH01 */ 746 .f = &w1_therm_family_DS18B20, 747 .convert = w1_DS18B20_convert_temp, 748 .get_conversion_time = w1_DS18B20_convert_time, 749 .set_resolution = w1_DS18B20_set_resolution, 750 .get_resolution = w1_DS18B20_get_resolution, 751 .write_data = w1_DS18B20_write_data, 752 .bulk_read = true 753 }, 754 { 755 .f = &w1_therm_family_DS28EA00, 756 .convert = w1_DS18B20_convert_temp, 757 .get_conversion_time = w1_DS18B20_convert_time, 758 .set_resolution = w1_DS18B20_set_resolution, 759 .get_resolution = w1_DS18B20_get_resolution, 760 .write_data = w1_DS18B20_write_data, 761 .bulk_read = false 762 }, 763 { 764 .f = &w1_therm_family_DS1825, 765 .convert = w1_DS18B20_convert_temp, 766 .get_conversion_time = w1_DS18B20_convert_time, 767 .set_resolution = w1_DS18B20_set_resolution, 768 .get_resolution = w1_DS18B20_get_resolution, 769 .write_data = w1_DS18B20_write_data, 770 .bulk_read = true 771 } 772 }; 773 774 /* Helpers Functions */ 775 776 /** 777 * device_family() - Retrieve a pointer on &struct w1_therm_family_converter 778 * @sl: slave to retrieve the device specific structure 779 * 780 * Return: pointer to the slaves's family converter, NULL if not known 781 */ 782 static struct w1_therm_family_converter *device_family(struct w1_slave *sl) 783 { 784 struct w1_therm_family_converter *ret = NULL; 785 int i; 786 787 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) { 788 if (w1_therm_families[i].f->fid == sl->family->fid) { 789 ret = &w1_therm_families[i]; 790 break; 791 } 792 } 793 return ret; 794 } 795 796 /** 797 * bus_mutex_lock() - Acquire the mutex 798 * @lock: w1 bus mutex to acquire 799 * 800 * It try to acquire the mutex W1_THERM_MAX_TRY times and wait 801 * W1_THERM_RETRY_DELAY between 2 attempts. 802 * 803 * Return: true is mutex is acquired and lock, false otherwise 804 */ 805 static inline bool bus_mutex_lock(struct mutex *lock) 806 { 807 int max_trying = W1_THERM_MAX_TRY; 808 809 /* try to acquire the mutex, if not, sleep retry_delay before retry) */ 810 while (mutex_lock_interruptible(lock) != 0 && max_trying > 0) { 811 unsigned long sleep_rem; 812 813 sleep_rem = msleep_interruptible(W1_THERM_RETRY_DELAY); 814 if (!sleep_rem) 815 max_trying--; 816 } 817 818 if (!max_trying) 819 return false; /* Didn't acquire the bus mutex */ 820 821 return true; 822 } 823 824 /** 825 * check_family_data() - Check if family data and specific functions are present 826 * @sl: W1 device data 827 * 828 * Return: 0 - OK, negative value - error 829 */ 830 static int check_family_data(struct w1_slave *sl) 831 { 832 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 833 dev_info(&sl->dev, 834 "%s: Device is not supported by the driver\n", __func__); 835 return -EINVAL; /* No device family */ 836 } 837 return 0; 838 } 839 840 /** 841 * support_bulk_read() - check if slave support bulk read 842 * @sl: device to check the ability 843 * 844 * Return: true if bulk read is supported, false if not or error 845 */ 846 static inline bool bulk_read_support(struct w1_slave *sl) 847 { 848 if (SLAVE_SPECIFIC_FUNC(sl)) 849 return SLAVE_SPECIFIC_FUNC(sl)->bulk_read; 850 851 dev_info(&sl->dev, 852 "%s: Device not supported by the driver\n", __func__); 853 854 return false; /* No device family */ 855 } 856 857 /** 858 * conversion_time() - get the Tconv for the slave 859 * @sl: device to get the conversion time 860 * 861 * On device supporting resolution settings, conversion time depend 862 * on the resolution setting. This helper function get the slave timing, 863 * depending on its current setting. 864 * 865 * Return: conversion time in ms, negative values are kernel error code 866 */ 867 static inline int conversion_time(struct w1_slave *sl) 868 { 869 if (SLAVE_SPECIFIC_FUNC(sl)) 870 return SLAVE_SPECIFIC_FUNC(sl)->get_conversion_time(sl); 871 872 dev_info(&sl->dev, 873 "%s: Device not supported by the driver\n", __func__); 874 875 return -ENODEV; /* No device family */ 876 } 877 878 /** 879 * temperature_from_RAM() - Convert the read info to temperature 880 * @sl: device that sent the RAM data 881 * @rom: read value on the slave device RAM 882 * 883 * Device dependent, the function bind the correct computation method. 884 * 885 * Return: temperature in 1/1000degC, 0 on error. 886 */ 887 static inline int temperature_from_RAM(struct w1_slave *sl, u8 rom[9]) 888 { 889 if (SLAVE_SPECIFIC_FUNC(sl)) 890 return SLAVE_SPECIFIC_FUNC(sl)->convert(rom); 891 892 dev_info(&sl->dev, 893 "%s: Device not supported by the driver\n", __func__); 894 895 return 0; /* No device family */ 896 } 897 898 /** 899 * int_to_short() - Safe casting of int to short 900 * 901 * @i: integer to be converted to short 902 * 903 * Device register use 1 byte to store signed integer. 904 * This helper function convert the int in a signed short, 905 * using the min/max values that device can measure as limits. 906 * min/max values are defined by macro. 907 * 908 * Return: a short in the range of min/max value 909 */ 910 static inline s8 int_to_short(int i) 911 { 912 /* Prepare to cast to short by eliminating out of range values */ 913 i = i > MAX_TEMP ? MAX_TEMP : i; 914 i = i < MIN_TEMP ? MIN_TEMP : i; 915 return (s8) i; 916 } 917 918 /* Interface Functions */ 919 920 static int w1_therm_add_slave(struct w1_slave *sl) 921 { 922 struct w1_therm_family_converter *sl_family_conv; 923 924 /* Allocate memory */ 925 sl->family_data = kzalloc(sizeof(struct w1_therm_family_data), 926 GFP_KERNEL); 927 if (!sl->family_data) 928 return -ENOMEM; 929 930 atomic_set(THERM_REFCNT(sl->family_data), 1); 931 932 /* Get a pointer to the device specific function struct */ 933 sl_family_conv = device_family(sl); 934 if (!sl_family_conv) { 935 kfree(sl->family_data); 936 return -ENODEV; 937 } 938 /* save this pointer to the device structure */ 939 SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv; 940 941 if (bulk_read_support(sl)) { 942 /* 943 * add the sys entry to trigger bulk_read 944 * at master level only the 1st time 945 */ 946 if (!bulk_read_device_counter) { 947 int err = device_create_file(&sl->master->dev, 948 &dev_attr_therm_bulk_read); 949 950 if (err) 951 dev_warn(&sl->dev, 952 "%s: Device has been added, but bulk read is unavailable. err=%d\n", 953 __func__, err); 954 } 955 /* Increment the counter */ 956 bulk_read_device_counter++; 957 } 958 959 /* Getting the power mode of the device {external, parasite} */ 960 SLAVE_POWERMODE(sl) = read_powermode(sl); 961 962 if (SLAVE_POWERMODE(sl) < 0) { 963 /* no error returned as device has been added */ 964 dev_warn(&sl->dev, 965 "%s: Device has been added, but power_mode may be corrupted. err=%d\n", 966 __func__, SLAVE_POWERMODE(sl)); 967 } 968 969 /* Getting the resolution of the device */ 970 if (SLAVE_SPECIFIC_FUNC(sl)->get_resolution) { 971 SLAVE_RESOLUTION(sl) = 972 SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl); 973 if (SLAVE_RESOLUTION(sl) < 0) { 974 /* no error returned as device has been added */ 975 dev_warn(&sl->dev, 976 "%s:Device has been added, but resolution may be corrupted. err=%d\n", 977 __func__, SLAVE_RESOLUTION(sl)); 978 } 979 } 980 981 /* Finally initialize convert_triggered flag */ 982 SLAVE_CONVERT_TRIGGERED(sl) = 0; 983 984 return 0; 985 } 986 987 static void w1_therm_remove_slave(struct w1_slave *sl) 988 { 989 int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data)); 990 991 if (bulk_read_support(sl)) { 992 bulk_read_device_counter--; 993 /* Delete the entry if no more device support the feature */ 994 if (!bulk_read_device_counter) 995 device_remove_file(&sl->master->dev, 996 &dev_attr_therm_bulk_read); 997 } 998 999 while (refcnt) { 1000 msleep(1000); 1001 refcnt = atomic_read(THERM_REFCNT(sl->family_data)); 1002 } 1003 kfree(sl->family_data); 1004 sl->family_data = NULL; 1005 } 1006 1007 /* Hardware Functions */ 1008 1009 /* Safe version of reset_select_slave - avoid using the one in w_io.c */ 1010 static int reset_select_slave(struct w1_slave *sl) 1011 { 1012 u8 match[9] = { W1_MATCH_ROM, }; 1013 u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num)); 1014 1015 if (w1_reset_bus(sl->master)) 1016 return -ENODEV; 1017 1018 memcpy(&match[1], &rn, 8); 1019 w1_write_block(sl->master, match, 9); 1020 1021 return 0; 1022 } 1023 1024 /** 1025 * w1_poll_completion - Poll for operation completion, with timeout 1026 * @dev_master: the device master of the bus 1027 * @tout_ms: timeout in milliseconds 1028 * 1029 * The device is answering 0's while an operation is in progress and 1's after it completes 1030 * Timeout may happen if the previous command was not recognised due to a line noise 1031 * 1032 * Return: 0 - OK, negative error - timeout 1033 */ 1034 static int w1_poll_completion(struct w1_master *dev_master, int tout_ms) 1035 { 1036 int i; 1037 1038 for (i = 0; i < tout_ms/W1_POLL_PERIOD; i++) { 1039 /* Delay is before poll, for device to recognize a command */ 1040 msleep(W1_POLL_PERIOD); 1041 1042 /* Compare all 8 bits to mitigate a noise on the bus */ 1043 if (w1_read_8(dev_master) == 0xFF) 1044 break; 1045 } 1046 if (i == tout_ms/W1_POLL_PERIOD) 1047 return -EIO; 1048 1049 return 0; 1050 } 1051 1052 static int convert_t(struct w1_slave *sl, struct therm_info *info) 1053 { 1054 struct w1_master *dev_master = sl->master; 1055 int max_trying = W1_THERM_MAX_TRY; 1056 int t_conv; 1057 int ret = -ENODEV; 1058 bool strong_pullup; 1059 1060 if (!sl->family_data) 1061 goto error; 1062 1063 strong_pullup = (w1_strong_pullup == 2 || 1064 (!SLAVE_POWERMODE(sl) && 1065 w1_strong_pullup)); 1066 1067 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 1068 dev_warn(&sl->dev, 1069 "%s: Disabling W1_THERM_POLL_COMPLETION in parasite power mode.\n", 1070 __func__); 1071 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION; 1072 } 1073 1074 /* get conversion duration device and id dependent */ 1075 t_conv = conversion_time(sl); 1076 1077 memset(info->rom, 0, sizeof(info->rom)); 1078 1079 /* prevent the slave from going away in sleep */ 1080 atomic_inc(THERM_REFCNT(sl->family_data)); 1081 1082 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1083 ret = -EAGAIN; /* Didn't acquire the mutex */ 1084 goto dec_refcnt; 1085 } 1086 1087 while (max_trying-- && ret) { /* ret should be 0 */ 1088 1089 info->verdict = 0; 1090 info->crc = 0; 1091 /* safe version to select slave */ 1092 if (!reset_select_slave(sl)) { 1093 unsigned long sleep_rem; 1094 1095 /* 750ms strong pullup (or delay) after the convert */ 1096 if (strong_pullup) 1097 w1_next_pullup(dev_master, t_conv); 1098 1099 w1_write_8(dev_master, W1_CONVERT_TEMP); 1100 1101 if (strong_pullup) { /*some device need pullup */ 1102 sleep_rem = msleep_interruptible(t_conv); 1103 if (sleep_rem != 0) { 1104 ret = -EINTR; 1105 goto mt_unlock; 1106 } 1107 mutex_unlock(&dev_master->bus_mutex); 1108 } else { /*no device need pullup */ 1109 if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 1110 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); 1111 if (ret) { 1112 dev_dbg(&sl->dev, "%s: Timeout\n", __func__); 1113 goto mt_unlock; 1114 } 1115 mutex_unlock(&dev_master->bus_mutex); 1116 } else { 1117 /* Fixed delay */ 1118 mutex_unlock(&dev_master->bus_mutex); 1119 sleep_rem = msleep_interruptible(t_conv); 1120 if (sleep_rem != 0) { 1121 ret = -EINTR; 1122 goto dec_refcnt; 1123 } 1124 } 1125 } 1126 ret = read_scratchpad(sl, info); 1127 1128 /* If enabled, check for conversion success */ 1129 if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) && 1130 (info->rom[6] == 0xC) && 1131 ((info->rom[1] == 0x5 && info->rom[0] == 0x50) || 1132 (info->rom[1] == 0x7 && info->rom[0] == 0xFF)) 1133 ) { 1134 /* Invalid reading (scratchpad byte 6 = 0xC) 1135 * due to insufficient conversion time 1136 * or power failure. 1137 */ 1138 ret = -EIO; 1139 } 1140 1141 goto dec_refcnt; 1142 } 1143 1144 } 1145 1146 mt_unlock: 1147 mutex_unlock(&dev_master->bus_mutex); 1148 dec_refcnt: 1149 atomic_dec(THERM_REFCNT(sl->family_data)); 1150 error: 1151 return ret; 1152 } 1153 1154 static int conv_time_measure(struct w1_slave *sl, int *conv_time) 1155 { 1156 struct therm_info inf, 1157 *info = &inf; 1158 struct w1_master *dev_master = sl->master; 1159 int max_trying = W1_THERM_MAX_TRY; 1160 int ret = -ENODEV; 1161 bool strong_pullup; 1162 1163 if (!sl->family_data) 1164 goto error; 1165 1166 strong_pullup = (w1_strong_pullup == 2 || 1167 (!SLAVE_POWERMODE(sl) && 1168 w1_strong_pullup)); 1169 1170 if (strong_pullup) { 1171 pr_info("%s: Measure with strong_pullup is not supported.\n", __func__); 1172 return -EINVAL; 1173 } 1174 1175 memset(info->rom, 0, sizeof(info->rom)); 1176 1177 /* prevent the slave from going away in sleep */ 1178 atomic_inc(THERM_REFCNT(sl->family_data)); 1179 1180 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1181 ret = -EAGAIN; /* Didn't acquire the mutex */ 1182 goto dec_refcnt; 1183 } 1184 1185 while (max_trying-- && ret) { /* ret should be 0 */ 1186 info->verdict = 0; 1187 info->crc = 0; 1188 /* safe version to select slave */ 1189 if (!reset_select_slave(sl)) { 1190 int j_start, j_end; 1191 1192 /*no device need pullup */ 1193 w1_write_8(dev_master, W1_CONVERT_TEMP); 1194 1195 j_start = jiffies; 1196 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); 1197 if (ret) { 1198 dev_dbg(&sl->dev, "%s: Timeout\n", __func__); 1199 goto mt_unlock; 1200 } 1201 j_end = jiffies; 1202 /* 1.2x increase for variation and changes over temperature range */ 1203 *conv_time = jiffies_to_msecs(j_end-j_start)*12/10; 1204 pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n", 1205 *conv_time, HZ); 1206 if (*conv_time <= CONV_TIME_MEASURE) { 1207 ret = -EIO; 1208 goto mt_unlock; 1209 } 1210 mutex_unlock(&dev_master->bus_mutex); 1211 ret = read_scratchpad(sl, info); 1212 goto dec_refcnt; 1213 } 1214 1215 } 1216 mt_unlock: 1217 mutex_unlock(&dev_master->bus_mutex); 1218 dec_refcnt: 1219 atomic_dec(THERM_REFCNT(sl->family_data)); 1220 error: 1221 return ret; 1222 } 1223 1224 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info) 1225 { 1226 struct w1_master *dev_master = sl->master; 1227 int max_trying = W1_THERM_MAX_TRY; 1228 int ret = -ENODEV; 1229 1230 info->verdict = 0; 1231 1232 if (!sl->family_data) 1233 goto error; 1234 1235 memset(info->rom, 0, sizeof(info->rom)); 1236 1237 /* prevent the slave from going away in sleep */ 1238 atomic_inc(THERM_REFCNT(sl->family_data)); 1239 1240 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1241 ret = -EAGAIN; /* Didn't acquire the mutex */ 1242 goto dec_refcnt; 1243 } 1244 1245 while (max_trying-- && ret) { /* ret should be 0 */ 1246 /* safe version to select slave */ 1247 if (!reset_select_slave(sl)) { 1248 u8 nb_bytes_read; 1249 1250 w1_write_8(dev_master, W1_READ_SCRATCHPAD); 1251 1252 nb_bytes_read = w1_read_block(dev_master, info->rom, 9); 1253 if (nb_bytes_read != 9) { 1254 dev_warn(&sl->dev, 1255 "w1_read_block(): returned %u instead of 9.\n", 1256 nb_bytes_read); 1257 ret = -EIO; 1258 } 1259 1260 info->crc = w1_calc_crc8(info->rom, 8); 1261 1262 if (info->rom[8] == info->crc) { 1263 info->verdict = 1; 1264 ret = 0; 1265 } else 1266 ret = -EIO; /* CRC not checked */ 1267 } 1268 1269 } 1270 mutex_unlock(&dev_master->bus_mutex); 1271 1272 dec_refcnt: 1273 atomic_dec(THERM_REFCNT(sl->family_data)); 1274 error: 1275 return ret; 1276 } 1277 1278 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes) 1279 { 1280 struct w1_master *dev_master = sl->master; 1281 int max_trying = W1_THERM_MAX_TRY; 1282 int ret = -ENODEV; 1283 1284 if (!sl->family_data) 1285 goto error; 1286 1287 /* prevent the slave from going away in sleep */ 1288 atomic_inc(THERM_REFCNT(sl->family_data)); 1289 1290 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1291 ret = -EAGAIN; /* Didn't acquire the mutex */ 1292 goto dec_refcnt; 1293 } 1294 1295 while (max_trying-- && ret) { /* ret should be 0 */ 1296 /* safe version to select slave */ 1297 if (!reset_select_slave(sl)) { 1298 w1_write_8(dev_master, W1_WRITE_SCRATCHPAD); 1299 w1_write_block(dev_master, data, nb_bytes); 1300 ret = 0; 1301 } 1302 } 1303 mutex_unlock(&dev_master->bus_mutex); 1304 1305 dec_refcnt: 1306 atomic_dec(THERM_REFCNT(sl->family_data)); 1307 error: 1308 return ret; 1309 } 1310 1311 static int copy_scratchpad(struct w1_slave *sl) 1312 { 1313 struct w1_master *dev_master = sl->master; 1314 int max_trying = W1_THERM_MAX_TRY; 1315 int t_write, ret = -ENODEV; 1316 bool strong_pullup; 1317 1318 if (!sl->family_data) 1319 goto error; 1320 1321 t_write = W1_THERM_EEPROM_WRITE_DELAY; 1322 strong_pullup = (w1_strong_pullup == 2 || 1323 (!SLAVE_POWERMODE(sl) && 1324 w1_strong_pullup)); 1325 1326 /* prevent the slave from going away in sleep */ 1327 atomic_inc(THERM_REFCNT(sl->family_data)); 1328 1329 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1330 ret = -EAGAIN; /* Didn't acquire the mutex */ 1331 goto dec_refcnt; 1332 } 1333 1334 while (max_trying-- && ret) { /* ret should be 0 */ 1335 /* safe version to select slave */ 1336 if (!reset_select_slave(sl)) { 1337 unsigned long sleep_rem; 1338 1339 /* 10ms strong pullup (or delay) after the convert */ 1340 if (strong_pullup) 1341 w1_next_pullup(dev_master, t_write); 1342 1343 w1_write_8(dev_master, W1_COPY_SCRATCHPAD); 1344 1345 if (strong_pullup) { 1346 sleep_rem = msleep_interruptible(t_write); 1347 if (sleep_rem != 0) { 1348 ret = -EINTR; 1349 goto mt_unlock; 1350 } 1351 } 1352 ret = 0; 1353 } 1354 1355 } 1356 1357 mt_unlock: 1358 mutex_unlock(&dev_master->bus_mutex); 1359 dec_refcnt: 1360 atomic_dec(THERM_REFCNT(sl->family_data)); 1361 error: 1362 return ret; 1363 } 1364 1365 static int recall_eeprom(struct w1_slave *sl) 1366 { 1367 struct w1_master *dev_master = sl->master; 1368 int max_trying = W1_THERM_MAX_TRY; 1369 int ret = -ENODEV; 1370 1371 if (!sl->family_data) 1372 goto error; 1373 1374 /* prevent the slave from going away in sleep */ 1375 atomic_inc(THERM_REFCNT(sl->family_data)); 1376 1377 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1378 ret = -EAGAIN; /* Didn't acquire the mutex */ 1379 goto dec_refcnt; 1380 } 1381 1382 while (max_trying-- && ret) { /* ret should be 0 */ 1383 /* safe version to select slave */ 1384 if (!reset_select_slave(sl)) { 1385 1386 w1_write_8(dev_master, W1_RECALL_EEPROM); 1387 ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM); 1388 } 1389 1390 } 1391 1392 mutex_unlock(&dev_master->bus_mutex); 1393 1394 dec_refcnt: 1395 atomic_dec(THERM_REFCNT(sl->family_data)); 1396 error: 1397 return ret; 1398 } 1399 1400 static int read_powermode(struct w1_slave *sl) 1401 { 1402 struct w1_master *dev_master = sl->master; 1403 int max_trying = W1_THERM_MAX_TRY; 1404 int ret = -ENODEV; 1405 1406 if (!sl->family_data) 1407 goto error; 1408 1409 /* prevent the slave from going away in sleep */ 1410 atomic_inc(THERM_REFCNT(sl->family_data)); 1411 1412 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1413 ret = -EAGAIN; /* Didn't acquire the mutex */ 1414 goto dec_refcnt; 1415 } 1416 1417 while ((max_trying--) && (ret < 0)) { 1418 /* safe version to select slave */ 1419 if (!reset_select_slave(sl)) { 1420 w1_write_8(dev_master, W1_READ_PSUPPLY); 1421 /* 1422 * Emit a read time slot and read only one bit, 1423 * 1 is externally powered, 1424 * 0 is parasite powered 1425 */ 1426 ret = w1_touch_bit(dev_master, 1); 1427 /* ret should be either 1 either 0 */ 1428 } 1429 } 1430 mutex_unlock(&dev_master->bus_mutex); 1431 1432 dec_refcnt: 1433 atomic_dec(THERM_REFCNT(sl->family_data)); 1434 error: 1435 return ret; 1436 } 1437 1438 static int trigger_bulk_read(struct w1_master *dev_master) 1439 { 1440 struct w1_slave *sl = NULL; /* used to iterate through slaves */ 1441 int max_trying = W1_THERM_MAX_TRY; 1442 int t_conv = 0; 1443 int ret = -ENODEV; 1444 bool strong_pullup = false; 1445 1446 /* 1447 * Check whether there are parasite powered device on the bus, 1448 * and compute duration of conversion for these devices 1449 * so we can apply a strong pullup if required 1450 */ 1451 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1452 if (!sl->family_data) 1453 goto error; 1454 if (bulk_read_support(sl)) { 1455 int t_cur = conversion_time(sl); 1456 1457 t_conv = t_cur > t_conv ? t_cur : t_conv; 1458 strong_pullup = strong_pullup || 1459 (w1_strong_pullup == 2 || 1460 (!SLAVE_POWERMODE(sl) && 1461 w1_strong_pullup)); 1462 } 1463 } 1464 1465 /* 1466 * t_conv is the max conversion time required on the bus 1467 * If its 0, no device support the bulk read feature 1468 */ 1469 if (!t_conv) 1470 goto error; 1471 1472 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1473 ret = -EAGAIN; /* Didn't acquire the mutex */ 1474 goto error; 1475 } 1476 1477 while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */ 1478 1479 if (!w1_reset_bus(dev_master)) { /* Just reset the bus */ 1480 unsigned long sleep_rem; 1481 1482 w1_write_8(dev_master, W1_SKIP_ROM); 1483 1484 if (strong_pullup) /* Apply pullup if required */ 1485 w1_next_pullup(dev_master, t_conv); 1486 1487 w1_write_8(dev_master, W1_CONVERT_TEMP); 1488 1489 /* set a flag to instruct that converT pending */ 1490 list_for_each_entry(sl, 1491 &dev_master->slist, w1_slave_entry) { 1492 if (bulk_read_support(sl)) 1493 SLAVE_CONVERT_TRIGGERED(sl) = -1; 1494 } 1495 1496 if (strong_pullup) { /* some device need pullup */ 1497 sleep_rem = msleep_interruptible(t_conv); 1498 if (sleep_rem != 0) { 1499 ret = -EINTR; 1500 goto mt_unlock; 1501 } 1502 mutex_unlock(&dev_master->bus_mutex); 1503 } else { 1504 mutex_unlock(&dev_master->bus_mutex); 1505 sleep_rem = msleep_interruptible(t_conv); 1506 if (sleep_rem != 0) { 1507 ret = -EINTR; 1508 goto set_flag; 1509 } 1510 } 1511 ret = 0; 1512 goto set_flag; 1513 } 1514 } 1515 1516 mt_unlock: 1517 mutex_unlock(&dev_master->bus_mutex); 1518 set_flag: 1519 /* set a flag to register convsersion is done */ 1520 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1521 if (bulk_read_support(sl)) 1522 SLAVE_CONVERT_TRIGGERED(sl) = 1; 1523 } 1524 error: 1525 return ret; 1526 } 1527 1528 /* Sysfs Interface definition */ 1529 1530 static ssize_t w1_slave_show(struct device *device, 1531 struct device_attribute *attr, char *buf) 1532 { 1533 struct w1_slave *sl = dev_to_w1_slave(device); 1534 struct therm_info info; 1535 u8 *family_data = sl->family_data; 1536 int ret, i; 1537 ssize_t c = PAGE_SIZE; 1538 1539 if (bulk_read_support(sl)) { 1540 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) { 1541 dev_dbg(device, 1542 "%s: Conversion in progress, retry later\n", 1543 __func__); 1544 return 0; 1545 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) { 1546 /* A bulk read has been issued, read the device RAM */ 1547 ret = read_scratchpad(sl, &info); 1548 SLAVE_CONVERT_TRIGGERED(sl) = 0; 1549 } else 1550 ret = convert_t(sl, &info); 1551 } else 1552 ret = convert_t(sl, &info); 1553 1554 if (ret < 0) { 1555 dev_dbg(device, 1556 "%s: Temperature data may be corrupted. err=%d\n", 1557 __func__, ret); 1558 return 0; 1559 } 1560 1561 for (i = 0; i < 9; ++i) 1562 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]); 1563 c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n", 1564 info.crc, (info.verdict) ? "YES" : "NO"); 1565 1566 if (info.verdict) 1567 memcpy(family_data, info.rom, sizeof(info.rom)); 1568 else 1569 dev_warn(device, "%s:Read failed CRC check\n", __func__); 1570 1571 for (i = 0; i < 9; ++i) 1572 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", 1573 ((u8 *)family_data)[i]); 1574 1575 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n", 1576 temperature_from_RAM(sl, info.rom)); 1577 1578 ret = PAGE_SIZE - c; 1579 return ret; 1580 } 1581 1582 static ssize_t w1_slave_store(struct device *device, 1583 struct device_attribute *attr, const char *buf, 1584 size_t size) 1585 { 1586 int val, ret = 0; 1587 struct w1_slave *sl = dev_to_w1_slave(device); 1588 1589 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */ 1590 1591 if (ret) { /* conversion error */ 1592 dev_info(device, 1593 "%s: conversion error. err= %d\n", __func__, ret); 1594 return size; /* return size to avoid call back again */ 1595 } 1596 1597 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1598 dev_info(device, 1599 "%s: Device not supported by the driver\n", __func__); 1600 return size; /* No device family */ 1601 } 1602 1603 if (val == 0) /* val=0 : trigger a EEPROM save */ 1604 ret = copy_scratchpad(sl); 1605 else { 1606 if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution) 1607 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val); 1608 } 1609 1610 if (ret) { 1611 dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret); 1612 /* Propagate error to userspace */ 1613 return ret; 1614 } 1615 SLAVE_RESOLUTION(sl) = val; 1616 /* Reset the conversion time to default - it depends on resolution */ 1617 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT; 1618 1619 return size; /* always return size to avoid infinite calling */ 1620 } 1621 1622 static ssize_t temperature_show(struct device *device, 1623 struct device_attribute *attr, char *buf) 1624 { 1625 struct w1_slave *sl = dev_to_w1_slave(device); 1626 struct therm_info info; 1627 int ret = 0; 1628 1629 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1630 dev_info(device, 1631 "%s: Device not supported by the driver\n", __func__); 1632 return 0; /* No device family */ 1633 } 1634 1635 if (bulk_read_support(sl)) { 1636 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) { 1637 dev_dbg(device, 1638 "%s: Conversion in progress, retry later\n", 1639 __func__); 1640 return 0; 1641 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) { 1642 /* A bulk read has been issued, read the device RAM */ 1643 ret = read_scratchpad(sl, &info); 1644 SLAVE_CONVERT_TRIGGERED(sl) = 0; 1645 } else 1646 ret = convert_t(sl, &info); 1647 } else 1648 ret = convert_t(sl, &info); 1649 1650 if (ret < 0) { 1651 dev_dbg(device, 1652 "%s: Temperature data may be corrupted. err=%d\n", 1653 __func__, ret); 1654 return 0; 1655 } 1656 1657 return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom)); 1658 } 1659 1660 static ssize_t ext_power_show(struct device *device, 1661 struct device_attribute *attr, char *buf) 1662 { 1663 struct w1_slave *sl = dev_to_w1_slave(device); 1664 1665 if (!sl->family_data) { 1666 dev_info(device, 1667 "%s: Device not supported by the driver\n", __func__); 1668 return 0; /* No device family */ 1669 } 1670 1671 /* Getting the power mode of the device {external, parasite} */ 1672 SLAVE_POWERMODE(sl) = read_powermode(sl); 1673 1674 if (SLAVE_POWERMODE(sl) < 0) { 1675 dev_dbg(device, 1676 "%s: Power_mode may be corrupted. err=%d\n", 1677 __func__, SLAVE_POWERMODE(sl)); 1678 } 1679 return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl)); 1680 } 1681 1682 static ssize_t resolution_show(struct device *device, 1683 struct device_attribute *attr, char *buf) 1684 { 1685 struct w1_slave *sl = dev_to_w1_slave(device); 1686 1687 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1688 dev_info(device, 1689 "%s: Device not supported by the driver\n", __func__); 1690 return 0; /* No device family */ 1691 } 1692 1693 /* get the correct function depending on the device */ 1694 SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl); 1695 if (SLAVE_RESOLUTION(sl) < 0) { 1696 dev_dbg(device, 1697 "%s: Resolution may be corrupted. err=%d\n", 1698 __func__, SLAVE_RESOLUTION(sl)); 1699 } 1700 1701 return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl)); 1702 } 1703 1704 static ssize_t resolution_store(struct device *device, 1705 struct device_attribute *attr, const char *buf, size_t size) 1706 { 1707 struct w1_slave *sl = dev_to_w1_slave(device); 1708 int val; 1709 int ret = 0; 1710 1711 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */ 1712 1713 if (ret) { /* conversion error */ 1714 dev_info(device, 1715 "%s: conversion error. err= %d\n", __func__, ret); 1716 return size; /* return size to avoid call back again */ 1717 } 1718 1719 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1720 dev_info(device, 1721 "%s: Device not supported by the driver\n", __func__); 1722 return size; /* No device family */ 1723 } 1724 1725 /* 1726 * Don't deal with the val enterd by user, 1727 * only device knows what is correct or not 1728 */ 1729 1730 /* get the correct function depending on the device */ 1731 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val); 1732 1733 if (ret) 1734 return ret; 1735 1736 SLAVE_RESOLUTION(sl) = val; 1737 /* Reset the conversion time to default because it depends on resolution */ 1738 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT; 1739 1740 return size; 1741 } 1742 1743 static ssize_t eeprom_cmd_store(struct device *device, 1744 struct device_attribute *attr, const char *buf, size_t size) 1745 { 1746 struct w1_slave *sl = dev_to_w1_slave(device); 1747 int ret = -EINVAL; /* Invalid argument */ 1748 1749 if (size == sizeof(EEPROM_CMD_WRITE)) { 1750 if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1)) 1751 ret = copy_scratchpad(sl); 1752 } else if (size == sizeof(EEPROM_CMD_READ)) { 1753 if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1)) 1754 ret = recall_eeprom(sl); 1755 } 1756 1757 if (ret) 1758 dev_info(device, "%s: error in process %d\n", __func__, ret); 1759 1760 return size; 1761 } 1762 1763 static ssize_t alarms_show(struct device *device, 1764 struct device_attribute *attr, char *buf) 1765 { 1766 struct w1_slave *sl = dev_to_w1_slave(device); 1767 int ret; 1768 s8 th = 0, tl = 0; 1769 struct therm_info scratchpad; 1770 1771 ret = read_scratchpad(sl, &scratchpad); 1772 1773 if (!ret) { 1774 th = scratchpad.rom[2]; /* TH is byte 2 */ 1775 tl = scratchpad.rom[3]; /* TL is byte 3 */ 1776 } else { 1777 dev_info(device, 1778 "%s: error reading alarms register %d\n", 1779 __func__, ret); 1780 } 1781 1782 return sprintf(buf, "%hd %hd\n", tl, th); 1783 } 1784 1785 static ssize_t alarms_store(struct device *device, 1786 struct device_attribute *attr, const char *buf, size_t size) 1787 { 1788 struct w1_slave *sl = dev_to_w1_slave(device); 1789 struct therm_info info; 1790 u8 new_config_register[3]; /* array of data to be written */ 1791 int temp, ret; 1792 char *token = NULL; 1793 s8 tl, th, tt; /* 1 byte per value + temp ring order */ 1794 char *p_args, *orig; 1795 1796 p_args = orig = kmalloc(size, GFP_KERNEL); 1797 /* Safe string copys as buf is const */ 1798 if (!p_args) { 1799 dev_warn(device, 1800 "%s: error unable to allocate memory %d\n", 1801 __func__, -ENOMEM); 1802 return size; 1803 } 1804 strcpy(p_args, buf); 1805 1806 /* Split string using space char */ 1807 token = strsep(&p_args, " "); 1808 1809 if (!token) { 1810 dev_info(device, 1811 "%s: error parsing args %d\n", __func__, -EINVAL); 1812 goto free_m; 1813 } 1814 1815 /* Convert 1st entry to int */ 1816 ret = kstrtoint (token, 10, &temp); 1817 if (ret) { 1818 dev_info(device, 1819 "%s: error parsing args %d\n", __func__, ret); 1820 goto free_m; 1821 } 1822 1823 tl = int_to_short(temp); 1824 1825 /* Split string using space char */ 1826 token = strsep(&p_args, " "); 1827 if (!token) { 1828 dev_info(device, 1829 "%s: error parsing args %d\n", __func__, -EINVAL); 1830 goto free_m; 1831 } 1832 /* Convert 2nd entry to int */ 1833 ret = kstrtoint (token, 10, &temp); 1834 if (ret) { 1835 dev_info(device, 1836 "%s: error parsing args %d\n", __func__, ret); 1837 goto free_m; 1838 } 1839 1840 /* Prepare to cast to short by eliminating out of range values */ 1841 th = int_to_short(temp); 1842 1843 /* Reorder if required th and tl */ 1844 if (tl > th) { 1845 tt = tl; tl = th; th = tt; 1846 } 1847 1848 /* 1849 * Read the scratchpad to change only the required bits 1850 * (th : byte 2 - tl: byte 3) 1851 */ 1852 ret = read_scratchpad(sl, &info); 1853 if (!ret) { 1854 new_config_register[0] = th; /* Byte 2 */ 1855 new_config_register[1] = tl; /* Byte 3 */ 1856 new_config_register[2] = info.rom[4];/* Byte 4 */ 1857 } else { 1858 dev_info(device, 1859 "%s: error reading from the slave device %d\n", 1860 __func__, ret); 1861 goto free_m; 1862 } 1863 1864 /* Write data in the device RAM */ 1865 if (!SLAVE_SPECIFIC_FUNC(sl)) { 1866 dev_info(device, 1867 "%s: Device not supported by the driver %d\n", 1868 __func__, -ENODEV); 1869 goto free_m; 1870 } 1871 1872 ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register); 1873 if (ret) 1874 dev_info(device, 1875 "%s: error writing to the slave device %d\n", 1876 __func__, ret); 1877 1878 free_m: 1879 /* free allocated memory */ 1880 kfree(orig); 1881 1882 return size; 1883 } 1884 1885 static ssize_t therm_bulk_read_store(struct device *device, 1886 struct device_attribute *attr, const char *buf, size_t size) 1887 { 1888 struct w1_master *dev_master = dev_to_w1_master(device); 1889 int ret = -EINVAL; /* Invalid argument */ 1890 1891 if (size == sizeof(BULK_TRIGGER_CMD)) 1892 if (!strncmp(buf, BULK_TRIGGER_CMD, 1893 sizeof(BULK_TRIGGER_CMD)-1)) 1894 ret = trigger_bulk_read(dev_master); 1895 1896 if (ret) 1897 dev_info(device, 1898 "%s: unable to trigger a bulk read on the bus. err=%d\n", 1899 __func__, ret); 1900 1901 return size; 1902 } 1903 1904 static ssize_t therm_bulk_read_show(struct device *device, 1905 struct device_attribute *attr, char *buf) 1906 { 1907 struct w1_master *dev_master = dev_to_w1_master(device); 1908 struct w1_slave *sl = NULL; 1909 int ret = 0; 1910 1911 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1912 if (sl->family_data) { 1913 if (bulk_read_support(sl)) { 1914 if (SLAVE_CONVERT_TRIGGERED(sl) == -1) { 1915 ret = -1; 1916 goto show_result; 1917 } 1918 if (SLAVE_CONVERT_TRIGGERED(sl) == 1) 1919 /* continue to check other slaves */ 1920 ret = 1; 1921 } 1922 } 1923 } 1924 show_result: 1925 return sprintf(buf, "%d\n", ret); 1926 } 1927 1928 static ssize_t conv_time_show(struct device *device, 1929 struct device_attribute *attr, char *buf) 1930 { 1931 struct w1_slave *sl = dev_to_w1_slave(device); 1932 1933 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1934 dev_info(device, 1935 "%s: Device is not supported by the driver\n", __func__); 1936 return 0; /* No device family */ 1937 } 1938 return sprintf(buf, "%d\n", conversion_time(sl)); 1939 } 1940 1941 static ssize_t conv_time_store(struct device *device, 1942 struct device_attribute *attr, const char *buf, size_t size) 1943 { 1944 int val, ret = 0; 1945 struct w1_slave *sl = dev_to_w1_slave(device); 1946 1947 if (kstrtoint(buf, 10, &val)) /* converting user entry to int */ 1948 return -EINVAL; 1949 1950 if (check_family_data(sl)) 1951 return -ENODEV; 1952 1953 if (val != CONV_TIME_MEASURE) { 1954 if (val >= CONV_TIME_DEFAULT) 1955 SLAVE_CONV_TIME_OVERRIDE(sl) = val; 1956 else 1957 return -EINVAL; 1958 1959 } else { 1960 int conv_time; 1961 1962 ret = conv_time_measure(sl, &conv_time); 1963 if (ret) 1964 return -EIO; 1965 SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time; 1966 } 1967 return size; 1968 } 1969 1970 static ssize_t features_show(struct device *device, 1971 struct device_attribute *attr, char *buf) 1972 { 1973 struct w1_slave *sl = dev_to_w1_slave(device); 1974 1975 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1976 dev_info(device, 1977 "%s: Device not supported by the driver\n", __func__); 1978 return 0; /* No device family */ 1979 } 1980 return sprintf(buf, "%u\n", SLAVE_FEATURES(sl)); 1981 } 1982 1983 static ssize_t features_store(struct device *device, 1984 struct device_attribute *attr, const char *buf, size_t size) 1985 { 1986 int val, ret = 0; 1987 bool strong_pullup; 1988 struct w1_slave *sl = dev_to_w1_slave(device); 1989 1990 ret = kstrtouint(buf, 10, &val); /* converting user entry to int */ 1991 if (ret) 1992 return -EINVAL; /* invalid number */ 1993 1994 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1995 dev_info(device, "%s: Device not supported by the driver\n", __func__); 1996 return -ENODEV; 1997 } 1998 1999 if ((val & W1_THERM_FEATURES_MASK) != val) 2000 return -EINVAL; 2001 2002 SLAVE_FEATURES(sl) = val; 2003 2004 strong_pullup = (w1_strong_pullup == 2 || 2005 (!SLAVE_POWERMODE(sl) && 2006 w1_strong_pullup)); 2007 2008 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 2009 dev_warn(&sl->dev, 2010 "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n", 2011 __func__); 2012 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION; 2013 } 2014 2015 return size; 2016 } 2017 2018 #if IS_REACHABLE(CONFIG_HWMON) 2019 static int w1_read_temp(struct device *device, u32 attr, int channel, 2020 long *val) 2021 { 2022 struct w1_slave *sl = dev_get_drvdata(device); 2023 struct therm_info info; 2024 int ret; 2025 2026 switch (attr) { 2027 case hwmon_temp_input: 2028 ret = convert_t(sl, &info); 2029 if (ret) 2030 return ret; 2031 2032 if (!info.verdict) { 2033 ret = -EIO; 2034 return ret; 2035 } 2036 2037 *val = temperature_from_RAM(sl, info.rom); 2038 ret = 0; 2039 break; 2040 default: 2041 ret = -EOPNOTSUPP; 2042 break; 2043 } 2044 2045 return ret; 2046 } 2047 #endif 2048 2049 #define W1_42_CHAIN 0x99 2050 #define W1_42_CHAIN_OFF 0x3C 2051 #define W1_42_CHAIN_OFF_INV 0xC3 2052 #define W1_42_CHAIN_ON 0x5A 2053 #define W1_42_CHAIN_ON_INV 0xA5 2054 #define W1_42_CHAIN_DONE 0x96 2055 #define W1_42_CHAIN_DONE_INV 0x69 2056 #define W1_42_COND_READ 0x0F 2057 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA 2058 #define W1_42_FINISHED_BYTE 0xFF 2059 static ssize_t w1_seq_show(struct device *device, 2060 struct device_attribute *attr, char *buf) 2061 { 2062 struct w1_slave *sl = dev_to_w1_slave(device); 2063 ssize_t c = PAGE_SIZE; 2064 int rv; 2065 int i; 2066 u8 ack; 2067 u64 rn; 2068 struct w1_reg_num *reg_num; 2069 int seq = 0; 2070 2071 mutex_lock(&sl->master->bus_mutex); 2072 /* Place all devices in CHAIN state */ 2073 if (w1_reset_bus(sl->master)) 2074 goto error; 2075 w1_write_8(sl->master, W1_SKIP_ROM); 2076 w1_write_8(sl->master, W1_42_CHAIN); 2077 w1_write_8(sl->master, W1_42_CHAIN_ON); 2078 w1_write_8(sl->master, W1_42_CHAIN_ON_INV); 2079 msleep(sl->master->pullup_duration); 2080 2081 /* check for acknowledgment */ 2082 ack = w1_read_8(sl->master); 2083 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2084 goto error; 2085 2086 /* In case the bus fails to send 0xFF, limit */ 2087 for (i = 0; i <= 64; i++) { 2088 if (w1_reset_bus(sl->master)) 2089 goto error; 2090 2091 w1_write_8(sl->master, W1_42_COND_READ); 2092 rv = w1_read_block(sl->master, (u8 *)&rn, 8); 2093 reg_num = (struct w1_reg_num *) &rn; 2094 if (reg_num->family == W1_42_FINISHED_BYTE) 2095 break; 2096 if (sl->reg_num.id == reg_num->id) 2097 seq = i; 2098 2099 w1_write_8(sl->master, W1_42_CHAIN); 2100 w1_write_8(sl->master, W1_42_CHAIN_DONE); 2101 w1_write_8(sl->master, W1_42_CHAIN_DONE_INV); 2102 w1_read_block(sl->master, &ack, sizeof(ack)); 2103 2104 /* check for acknowledgment */ 2105 ack = w1_read_8(sl->master); 2106 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2107 goto error; 2108 2109 } 2110 2111 /* Exit from CHAIN state */ 2112 if (w1_reset_bus(sl->master)) 2113 goto error; 2114 w1_write_8(sl->master, W1_SKIP_ROM); 2115 w1_write_8(sl->master, W1_42_CHAIN); 2116 w1_write_8(sl->master, W1_42_CHAIN_OFF); 2117 w1_write_8(sl->master, W1_42_CHAIN_OFF_INV); 2118 2119 /* check for acknowledgment */ 2120 ack = w1_read_8(sl->master); 2121 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2122 goto error; 2123 mutex_unlock(&sl->master->bus_mutex); 2124 2125 c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq); 2126 return PAGE_SIZE - c; 2127 error: 2128 mutex_unlock(&sl->master->bus_mutex); 2129 return -EIO; 2130 } 2131 2132 static int __init w1_therm_init(void) 2133 { 2134 int err, i; 2135 2136 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) { 2137 err = w1_register_family(w1_therm_families[i].f); 2138 if (err) 2139 w1_therm_families[i].broken = 1; 2140 } 2141 2142 return 0; 2143 } 2144 2145 static void __exit w1_therm_fini(void) 2146 { 2147 int i; 2148 2149 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) 2150 if (!w1_therm_families[i].broken) 2151 w1_unregister_family(w1_therm_families[i].f); 2152 } 2153 2154 module_init(w1_therm_init); 2155 module_exit(w1_therm_fini); 2156 2157 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); 2158 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family."); 2159 MODULE_LICENSE("GPL"); 2160 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20)); 2161 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822)); 2162 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20)); 2163 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825)); 2164 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00)); 2165