1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * w1_therm.c 4 * 5 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> 6 */ 7 8 #include <asm/types.h> 9 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/moduleparam.h> 13 #include <linux/sched.h> 14 #include <linux/device.h> 15 #include <linux/types.h> 16 #include <linux/slab.h> 17 #include <linux/delay.h> 18 #include <linux/hwmon.h> 19 #include <linux/string.h> 20 #include <linux/jiffies.h> 21 22 #include <linux/w1.h> 23 24 #define W1_THERM_DS18S20 0x10 25 #define W1_THERM_DS1822 0x22 26 #define W1_THERM_DS18B20 0x28 27 #define W1_THERM_DS1825 0x3B 28 #define W1_THERM_DS28EA00 0x42 29 30 /* 31 * Allow the strong pullup to be disabled, but default to enabled. 32 * If it was disabled a parasite powered device might not get the require 33 * current to do a temperature conversion. If it is enabled parasite powered 34 * devices have a better chance of getting the current required. 35 * In case the parasite power-detection is not working (seems to be the case 36 * for some DS18S20) the strong pullup can also be forced, regardless of the 37 * power state of the devices. 38 * 39 * Summary of options: 40 * - strong_pullup = 0 Disable strong pullup completely 41 * - strong_pullup = 1 Enable automatic strong pullup detection 42 * - strong_pullup = 2 Force strong pullup 43 */ 44 static int w1_strong_pullup = 1; 45 module_param_named(strong_pullup, w1_strong_pullup, int, 0); 46 47 /* Counter for devices supporting bulk reading */ 48 static u16 bulk_read_device_counter; /* =0 as per C standard */ 49 50 /* This command should be in public header w1.h but is not */ 51 #define W1_RECALL_EEPROM 0xB8 52 53 /* Nb of try for an operation */ 54 #define W1_THERM_MAX_TRY 5 55 56 /* ms delay to retry bus mutex */ 57 #define W1_THERM_RETRY_DELAY 20 58 59 /* delay in ms to write in EEPROM */ 60 #define W1_THERM_EEPROM_WRITE_DELAY 10 61 62 #define EEPROM_CMD_WRITE "save" /* cmd for write eeprom sysfs */ 63 #define EEPROM_CMD_READ "restore" /* cmd for read eeprom sysfs */ 64 #define BULK_TRIGGER_CMD "trigger" /* cmd to trigger a bulk read */ 65 66 #define MIN_TEMP -55 /* min temperature that can be measured */ 67 #define MAX_TEMP 125 /* max temperature that can be measured */ 68 69 /* Allowed values for sysfs conv_time attribute */ 70 #define CONV_TIME_DEFAULT 0 71 #define CONV_TIME_MEASURE 1 72 73 /* Bits in sysfs "features" value */ 74 #define W1_THERM_CHECK_RESULT 1 /* Enable conversion success check */ 75 #define W1_THERM_POLL_COMPLETION 2 /* Poll for conversion completion */ 76 #define W1_THERM_FEATURES_MASK 3 /* All values mask */ 77 78 /* Poll period in milliseconds. Should be less then a shortest operation on the device */ 79 #define W1_POLL_PERIOD 32 80 #define W1_POLL_CONVERT_TEMP 2000 /* Timeout for W1_CONVERT_TEMP, ms */ 81 #define W1_POLL_RECALL_EEPROM 500 /* Timeout for W1_RECALL_EEPROM, ms*/ 82 83 /* Masks for resolution functions, work with all devices */ 84 /* Bit mask for config register for all devices, bits 7,6,5 */ 85 #define W1_THERM_RESOLUTION_MASK 0xE0 86 /* Bit offset of resolution in config register for all devices */ 87 #define W1_THERM_RESOLUTION_SHIFT 5 88 /* Bit offset of resolution in config register for all devices */ 89 #define W1_THERM_RESOLUTION_SHIFT 5 90 /* Add this to bit value to get resolution */ 91 #define W1_THERM_RESOLUTION_MIN 9 92 /* Maximum allowed value */ 93 #define W1_THERM_RESOLUTION_MAX 14 94 95 /* Helpers Macros */ 96 97 /* 98 * return a pointer on the slave w1_therm_family_converter struct: 99 * always test family data existence before using this macro 100 */ 101 #define SLAVE_SPECIFIC_FUNC(sl) \ 102 (((struct w1_therm_family_data *)(sl->family_data))->specific_functions) 103 104 /* 105 * return the power mode of the sl slave : 1-ext, 0-parasite, <0 unknown 106 * always test family data existence before using this macro 107 */ 108 #define SLAVE_POWERMODE(sl) \ 109 (((struct w1_therm_family_data *)(sl->family_data))->external_powered) 110 111 /* 112 * return the resolution in bit of the sl slave : <0 unknown 113 * always test family data existence before using this macro 114 */ 115 #define SLAVE_RESOLUTION(sl) \ 116 (((struct w1_therm_family_data *)(sl->family_data))->resolution) 117 118 /* 119 * return the conv_time_override of the sl slave 120 * always test family data existence before using this macro 121 */ 122 #define SLAVE_CONV_TIME_OVERRIDE(sl) \ 123 (((struct w1_therm_family_data *)(sl->family_data))->conv_time_override) 124 125 /* 126 * return the features of the sl slave 127 * always test family data existence before using this macro 128 */ 129 #define SLAVE_FEATURES(sl) \ 130 (((struct w1_therm_family_data *)(sl->family_data))->features) 131 132 /* 133 * return whether or not a converT command has been issued to the slave 134 * * 0: no bulk read is pending 135 * * -1: conversion is in progress 136 * * 1: conversion done, result to be read 137 */ 138 #define SLAVE_CONVERT_TRIGGERED(sl) \ 139 (((struct w1_therm_family_data *)(sl->family_data))->convert_triggered) 140 141 /* return the address of the refcnt in the family data */ 142 #define THERM_REFCNT(family_data) \ 143 (&((struct w1_therm_family_data *)family_data)->refcnt) 144 145 /* Structs definition */ 146 147 /** 148 * struct w1_therm_family_converter - bind device specific functions 149 * @broken: flag for non-registred families 150 * @reserved: not used here 151 * @f: pointer to the device binding structure 152 * @convert: pointer to the device conversion function 153 * @get_conversion_time: pointer to the device conversion time function 154 * @set_resolution: pointer to the device set_resolution function 155 * @get_resolution: pointer to the device get_resolution function 156 * @write_data: pointer to the device writing function (2 or 3 bytes) 157 * @bulk_read: true if device family support bulk read, false otherwise 158 */ 159 struct w1_therm_family_converter { 160 u8 broken; 161 u16 reserved; 162 struct w1_family *f; 163 int (*convert)(u8 rom[9]); 164 int (*get_conversion_time)(struct w1_slave *sl); 165 int (*set_resolution)(struct w1_slave *sl, int val); 166 int (*get_resolution)(struct w1_slave *sl); 167 int (*write_data)(struct w1_slave *sl, const u8 *data); 168 bool bulk_read; 169 }; 170 171 /** 172 * struct w1_therm_family_data - device data 173 * @rom: ROM device id (64bit Lasered ROM code + 1 CRC byte) 174 * @refcnt: ref count 175 * @external_powered: 1 device powered externally, 176 * 0 device parasite powered, 177 * -x error or undefined 178 * @resolution: current device resolution 179 * @convert_triggered: conversion state of the device 180 * @conv_time_override: user selected conversion time or CONV_TIME_DEFAULT 181 * @features: bit mask - enable temperature validity check, poll for completion 182 * @specific_functions: pointer to struct of device specific function 183 */ 184 struct w1_therm_family_data { 185 uint8_t rom[9]; 186 atomic_t refcnt; 187 int external_powered; 188 int resolution; 189 int convert_triggered; 190 int conv_time_override; 191 unsigned int features; 192 struct w1_therm_family_converter *specific_functions; 193 }; 194 195 /** 196 * struct therm_info - store temperature reading 197 * @rom: read device data (8 data bytes + 1 CRC byte) 198 * @crc: computed crc from rom 199 * @verdict: 1 crc checked, 0 crc not matching 200 */ 201 struct therm_info { 202 u8 rom[9]; 203 u8 crc; 204 u8 verdict; 205 }; 206 207 /* Hardware Functions declaration */ 208 209 /** 210 * reset_select_slave() - reset and select a slave 211 * @sl: the slave to select 212 * 213 * Resets the bus and select the slave by sending a ROM MATCH cmd 214 * w1_reset_select_slave() from w1_io.c could not be used here because 215 * it sent a SKIP ROM command if only one device is on the line. 216 * At the beginning of the such process, sl->master->slave_count is 1 even if 217 * more devices are on the line, causing collision on the line. 218 * 219 * Context: The w1 master lock must be held. 220 * 221 * Return: 0 if success, negative kernel error code otherwise. 222 */ 223 static int reset_select_slave(struct w1_slave *sl); 224 225 /** 226 * convert_t() - Query the device for temperature conversion and read 227 * @sl: pointer to the slave to read 228 * @info: pointer to a structure to store the read results 229 * 230 * Return: 0 if success, -kernel error code otherwise 231 */ 232 static int convert_t(struct w1_slave *sl, struct therm_info *info); 233 234 /** 235 * read_scratchpad() - read the data in device RAM 236 * @sl: pointer to the slave to read 237 * @info: pointer to a structure to store the read results 238 * 239 * Return: 0 if success, -kernel error code otherwise 240 */ 241 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info); 242 243 /** 244 * write_scratchpad() - write nb_bytes in the device RAM 245 * @sl: pointer to the slave to write in 246 * @data: pointer to an array of 3 bytes, as 3 bytes MUST be written 247 * @nb_bytes: number of bytes to be written (2 for DS18S20, 3 otherwise) 248 * 249 * Return: 0 if success, -kernel error code otherwise 250 */ 251 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes); 252 253 /** 254 * copy_scratchpad() - Copy the content of scratchpad in device EEPROM 255 * @sl: slave involved 256 * 257 * Return: 0 if success, -kernel error code otherwise 258 */ 259 static int copy_scratchpad(struct w1_slave *sl); 260 261 /** 262 * recall_eeprom() - Restore EEPROM data to device RAM 263 * @sl: slave involved 264 * 265 * Return: 0 if success, -kernel error code otherwise 266 */ 267 static int recall_eeprom(struct w1_slave *sl); 268 269 /** 270 * read_powermode() - Query the power mode of the slave 271 * @sl: slave to retrieve the power mode 272 * 273 * Ask the device to get its power mode (external or parasite) 274 * and store the power status in the &struct w1_therm_family_data. 275 * 276 * Return: 277 * * 0 parasite powered device 278 * * 1 externally powered device 279 * * <0 kernel error code 280 */ 281 static int read_powermode(struct w1_slave *sl); 282 283 /** 284 * trigger_bulk_read() - function to trigger a bulk read on the bus 285 * @dev_master: the device master of the bus 286 * 287 * Send a SKIP ROM follow by a CONVERT T command 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 * const 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_DS1825_convert_time(struct w1_slave *sl) 578 { 579 int ret; 580 581 if (!sl->family_data) 582 return -ENODEV; /* device unknown */ 583 584 if (SLAVE_CONV_TIME_OVERRIDE(sl) != CONV_TIME_DEFAULT) 585 return SLAVE_CONV_TIME_OVERRIDE(sl); 586 587 /* Return the conversion time, depending on resolution, 588 * select maximum conversion time among all compatible devices 589 */ 590 switch (SLAVE_RESOLUTION(sl)) { 591 case 9: 592 ret = 95; 593 break; 594 case 10: 595 ret = 190; 596 break; 597 case 11: 598 ret = 375; 599 break; 600 case 12: 601 ret = 750; 602 break; 603 case 14: 604 ret = 100; /* MAX31850 only. Datasheet says 100ms */ 605 break; 606 default: 607 ret = 750; 608 } 609 return ret; 610 } 611 612 static inline int w1_DS18B20_write_data(struct w1_slave *sl, 613 const u8 *data) 614 { 615 return write_scratchpad(sl, data, 3); 616 } 617 618 static inline int w1_DS18S20_write_data(struct w1_slave *sl, 619 const u8 *data) 620 { 621 /* No config register */ 622 return write_scratchpad(sl, data, 2); 623 } 624 625 static inline int w1_DS18B20_set_resolution(struct w1_slave *sl, int val) 626 { 627 int ret; 628 struct therm_info info, info2; 629 630 /* DS18B20 resolution is 9 to 12 bits */ 631 /* GX20MH01 resolution is 9 to 14 bits */ 632 /* MAX31850 resolution is fixed 14 bits */ 633 if (val < W1_THERM_RESOLUTION_MIN || val > W1_THERM_RESOLUTION_MAX) 634 return -EINVAL; 635 636 /* Calc bit value from resolution */ 637 val = (val - W1_THERM_RESOLUTION_MIN) << W1_THERM_RESOLUTION_SHIFT; 638 639 /* 640 * Read the scratchpad to change only the required bits 641 * (bit5 & bit 6 from byte 4) 642 */ 643 ret = read_scratchpad(sl, &info); 644 645 if (ret) 646 return ret; 647 648 649 info.rom[4] &= ~W1_THERM_RESOLUTION_MASK; 650 info.rom[4] |= val; 651 652 /* Write data in the device RAM */ 653 ret = w1_DS18B20_write_data(sl, info.rom + 2); 654 if (ret) 655 return ret; 656 657 /* Have to read back the resolution to verify an actual value 658 * GX20MH01 and DS18B20 are indistinguishable by family number, but resolutions differ 659 * Some DS18B20 clones don't support resolution change 660 */ 661 ret = read_scratchpad(sl, &info2); 662 if (ret) 663 /* Scratchpad read fail */ 664 return ret; 665 666 if ((info2.rom[4] & W1_THERM_RESOLUTION_MASK) == (info.rom[4] & W1_THERM_RESOLUTION_MASK)) 667 return 0; 668 669 /* Resolution verify error */ 670 return -EIO; 671 } 672 673 static inline int w1_DS18B20_get_resolution(struct w1_slave *sl) 674 { 675 int ret; 676 int resolution; 677 struct therm_info info; 678 679 ret = read_scratchpad(sl, &info); 680 681 if (ret) 682 return ret; 683 684 resolution = ((info.rom[4] & W1_THERM_RESOLUTION_MASK) >> W1_THERM_RESOLUTION_SHIFT) 685 + W1_THERM_RESOLUTION_MIN; 686 /* GX20MH01 has one special case: 687 * >=14 means 14 bits when getting resolution from bit value. 688 * MAX31850 delivers fixed 15 and has 14 bits. 689 * Other devices have no more then 12 bits. 690 */ 691 if (resolution > W1_THERM_RESOLUTION_MAX) 692 resolution = W1_THERM_RESOLUTION_MAX; 693 694 return resolution; 695 } 696 697 /** 698 * w1_DS18B20_convert_temp() - temperature computation for DS18B20 699 * @rom: data read from device RAM (8 data bytes + 1 CRC byte) 700 * 701 * Can be called for any DS18B20 compliant device. 702 * 703 * Return: value in millidegrees Celsius. 704 */ 705 static inline int w1_DS18B20_convert_temp(u8 rom[9]) 706 { 707 u16 bv; 708 s16 t; 709 710 /* Signed 16-bit value to unsigned, cpu order */ 711 bv = le16_to_cpup((__le16 *)rom); 712 713 /* Config register bit R2 = 1 - GX20MH01 in 13 or 14 bit resolution mode */ 714 if (rom[4] & 0x80) { 715 /* Insert two temperature bits from config register */ 716 /* Avoid arithmetic shift of signed value */ 717 bv = (bv << 2) | (rom[4] & 3); 718 t = (s16) bv; /* Degrees, lowest bit is 2^-6 */ 719 return (int)t * 1000 / 64; /* Sign-extend to int; millidegrees */ 720 } 721 t = (s16)bv; /* Degrees, lowest bit is 2^-4 */ 722 return (int)t * 1000 / 16; /* Sign-extend to int; millidegrees */ 723 } 724 725 /** 726 * w1_DS18S20_convert_temp() - temperature computation for DS18S20 727 * @rom: data read from device RAM (8 data bytes + 1 CRC byte) 728 * 729 * Can be called for any DS18S20 compliant device. 730 * 731 * Return: value in millidegrees Celsius. 732 */ 733 static inline int w1_DS18S20_convert_temp(u8 rom[9]) 734 { 735 int t, h; 736 737 if (!rom[7]) { 738 pr_debug("%s: Invalid argument for conversion\n", __func__); 739 return 0; 740 } 741 742 if (rom[1] == 0) 743 t = ((s32)rom[0] >> 1)*1000; 744 else 745 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1); 746 747 t -= 250; 748 h = 1000*((s32)rom[7] - (s32)rom[6]); 749 h /= (s32)rom[7]; 750 t += h; 751 752 return t; 753 } 754 755 /** 756 * w1_DS1825_convert_temp() - temperature computation for DS1825 757 * @rom: data read from device RAM (8 data bytes + 1 CRC byte) 758 * 759 * Can be called for any DS1825 compliant device. 760 * Is used by MAX31850, too 761 * 762 * Return: value in millidegrees Celsius. 763 */ 764 765 static inline int w1_DS1825_convert_temp(u8 rom[9]) 766 { 767 u16 bv; 768 s16 t; 769 770 /* Signed 16-bit value to unsigned, cpu order */ 771 bv = le16_to_cpup((__le16 *)rom); 772 773 /* Config register bit 7 = 1 - MA31850 found, 14 bit resolution */ 774 if (rom[4] & 0x80) { 775 /* Mask out bits 0 (Fault) and 1 (Reserved) */ 776 /* Avoid arithmetic shift of signed value */ 777 bv = (bv & 0xFFFC); /* Degrees, lowest 4 bits are 2^-1, 2^-2 and 2 zero bits */ 778 } 779 t = (s16)bv; /* Degrees, lowest bit is 2^-4 */ 780 return (int)t * 1000 / 16; /* Sign-extend to int; millidegrees */ 781 } 782 783 /* Device capability description */ 784 /* GX20MH01 device shares family number and structure with DS18B20 */ 785 786 static struct w1_therm_family_converter w1_therm_families[] = { 787 { 788 .f = &w1_therm_family_DS18S20, 789 .convert = w1_DS18S20_convert_temp, 790 .get_conversion_time = w1_DS18S20_convert_time, 791 .set_resolution = NULL, /* no config register */ 792 .get_resolution = NULL, /* no config register */ 793 .write_data = w1_DS18S20_write_data, 794 .bulk_read = true 795 }, 796 { 797 .f = &w1_therm_family_DS1822, 798 .convert = w1_DS18B20_convert_temp, 799 .get_conversion_time = w1_DS18B20_convert_time, 800 .set_resolution = w1_DS18B20_set_resolution, 801 .get_resolution = w1_DS18B20_get_resolution, 802 .write_data = w1_DS18B20_write_data, 803 .bulk_read = true 804 }, 805 { 806 /* Also used for GX20MH01 */ 807 .f = &w1_therm_family_DS18B20, 808 .convert = w1_DS18B20_convert_temp, 809 .get_conversion_time = w1_DS18B20_convert_time, 810 .set_resolution = w1_DS18B20_set_resolution, 811 .get_resolution = w1_DS18B20_get_resolution, 812 .write_data = w1_DS18B20_write_data, 813 .bulk_read = true 814 }, 815 { 816 .f = &w1_therm_family_DS28EA00, 817 .convert = w1_DS18B20_convert_temp, 818 .get_conversion_time = w1_DS18B20_convert_time, 819 .set_resolution = w1_DS18B20_set_resolution, 820 .get_resolution = w1_DS18B20_get_resolution, 821 .write_data = w1_DS18B20_write_data, 822 .bulk_read = false 823 }, 824 { 825 /* Also used for MAX31850 */ 826 .f = &w1_therm_family_DS1825, 827 .convert = w1_DS1825_convert_temp, 828 .get_conversion_time = w1_DS1825_convert_time, 829 .set_resolution = w1_DS18B20_set_resolution, 830 .get_resolution = w1_DS18B20_get_resolution, 831 .write_data = w1_DS18B20_write_data, 832 .bulk_read = true 833 } 834 }; 835 836 /* Helpers Functions */ 837 838 /** 839 * device_family() - Retrieve a pointer on &struct w1_therm_family_converter 840 * @sl: slave to retrieve the device specific structure 841 * 842 * Return: pointer to the slaves's family converter, NULL if not known 843 */ 844 static struct w1_therm_family_converter *device_family(struct w1_slave *sl) 845 { 846 struct w1_therm_family_converter *ret = NULL; 847 int i; 848 849 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) { 850 if (w1_therm_families[i].f->fid == sl->family->fid) { 851 ret = &w1_therm_families[i]; 852 break; 853 } 854 } 855 return ret; 856 } 857 858 /** 859 * bus_mutex_lock() - Acquire the mutex 860 * @lock: w1 bus mutex to acquire 861 * 862 * It try to acquire the mutex W1_THERM_MAX_TRY times and wait 863 * W1_THERM_RETRY_DELAY between 2 attempts. 864 * 865 * Return: true is mutex is acquired and lock, false otherwise 866 */ 867 static inline bool bus_mutex_lock(struct mutex *lock) 868 { 869 int max_trying = W1_THERM_MAX_TRY; 870 871 /* try to acquire the mutex, if not, sleep retry_delay before retry) */ 872 while (mutex_lock_interruptible(lock) != 0 && max_trying > 0) { 873 unsigned long sleep_rem; 874 875 sleep_rem = msleep_interruptible(W1_THERM_RETRY_DELAY); 876 if (!sleep_rem) 877 max_trying--; 878 } 879 880 if (!max_trying) 881 return false; /* Didn't acquire the bus mutex */ 882 883 return true; 884 } 885 886 /** 887 * check_family_data() - Check if family data and specific functions are present 888 * @sl: W1 device data 889 * 890 * Return: 0 - OK, negative value - error 891 */ 892 static int check_family_data(struct w1_slave *sl) 893 { 894 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 895 dev_info(&sl->dev, 896 "%s: Device is not supported by the driver\n", __func__); 897 return -EINVAL; /* No device family */ 898 } 899 return 0; 900 } 901 902 /** 903 * bulk_read_support() - check if slave support bulk read 904 * @sl: device to check the ability 905 * 906 * Return: true if bulk read is supported, false if not or error 907 */ 908 static inline bool bulk_read_support(struct w1_slave *sl) 909 { 910 if (SLAVE_SPECIFIC_FUNC(sl)) 911 return SLAVE_SPECIFIC_FUNC(sl)->bulk_read; 912 913 dev_info(&sl->dev, 914 "%s: Device not supported by the driver\n", __func__); 915 916 return false; /* No device family */ 917 } 918 919 /** 920 * conversion_time() - get the Tconv for the slave 921 * @sl: device to get the conversion time 922 * 923 * On device supporting resolution settings, conversion time depend 924 * on the resolution setting. This helper function get the slave timing, 925 * depending on its current setting. 926 * 927 * Return: conversion time in ms, negative values are kernel error code 928 */ 929 static inline int conversion_time(struct w1_slave *sl) 930 { 931 if (SLAVE_SPECIFIC_FUNC(sl)) 932 return SLAVE_SPECIFIC_FUNC(sl)->get_conversion_time(sl); 933 934 dev_info(&sl->dev, 935 "%s: Device not supported by the driver\n", __func__); 936 937 return -ENODEV; /* No device family */ 938 } 939 940 /** 941 * temperature_from_RAM() - Convert the read info to temperature 942 * @sl: device that sent the RAM data 943 * @rom: read value on the slave device RAM 944 * 945 * Device dependent, the function bind the correct computation method. 946 * 947 * Return: temperature in 1/1000degC, 0 on error. 948 */ 949 static inline int temperature_from_RAM(struct w1_slave *sl, u8 rom[9]) 950 { 951 if (SLAVE_SPECIFIC_FUNC(sl)) 952 return SLAVE_SPECIFIC_FUNC(sl)->convert(rom); 953 954 dev_info(&sl->dev, 955 "%s: Device not supported by the driver\n", __func__); 956 957 return 0; /* No device family */ 958 } 959 960 /** 961 * int_to_short() - Safe casting of int to short 962 * 963 * @i: integer to be converted to short 964 * 965 * Device register use 1 byte to store signed integer. 966 * This helper function convert the int in a signed short, 967 * using the min/max values that device can measure as limits. 968 * min/max values are defined by macro. 969 * 970 * Return: a short in the range of min/max value 971 */ 972 static inline s8 int_to_short(int i) 973 { 974 /* Prepare to cast to short by eliminating out of range values */ 975 i = clamp(i, MIN_TEMP, MAX_TEMP); 976 return (s8) i; 977 } 978 979 /* Interface Functions */ 980 981 static int w1_therm_add_slave(struct w1_slave *sl) 982 { 983 struct w1_therm_family_converter *sl_family_conv; 984 985 /* Allocate memory */ 986 sl->family_data = kzalloc(sizeof(struct w1_therm_family_data), 987 GFP_KERNEL); 988 if (!sl->family_data) 989 return -ENOMEM; 990 991 atomic_set(THERM_REFCNT(sl->family_data), 1); 992 993 /* Get a pointer to the device specific function struct */ 994 sl_family_conv = device_family(sl); 995 if (!sl_family_conv) { 996 kfree(sl->family_data); 997 return -ENODEV; 998 } 999 /* save this pointer to the device structure */ 1000 SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv; 1001 1002 if (bulk_read_support(sl)) { 1003 /* 1004 * add the sys entry to trigger bulk_read 1005 * at master level only the 1st time 1006 */ 1007 if (!bulk_read_device_counter) { 1008 int err = device_create_file(&sl->master->dev, 1009 &dev_attr_therm_bulk_read); 1010 1011 if (err) 1012 dev_warn(&sl->dev, 1013 "%s: Device has been added, but bulk read is unavailable. err=%d\n", 1014 __func__, err); 1015 } 1016 /* Increment the counter */ 1017 bulk_read_device_counter++; 1018 } 1019 1020 /* Getting the power mode of the device {external, parasite} */ 1021 SLAVE_POWERMODE(sl) = read_powermode(sl); 1022 1023 if (SLAVE_POWERMODE(sl) < 0) { 1024 /* no error returned as device has been added */ 1025 dev_warn(&sl->dev, 1026 "%s: Device has been added, but power_mode may be corrupted. err=%d\n", 1027 __func__, SLAVE_POWERMODE(sl)); 1028 } 1029 1030 /* Getting the resolution of the device */ 1031 if (SLAVE_SPECIFIC_FUNC(sl)->get_resolution) { 1032 SLAVE_RESOLUTION(sl) = 1033 SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl); 1034 if (SLAVE_RESOLUTION(sl) < 0) { 1035 /* no error returned as device has been added */ 1036 dev_warn(&sl->dev, 1037 "%s:Device has been added, but resolution may be corrupted. err=%d\n", 1038 __func__, SLAVE_RESOLUTION(sl)); 1039 } 1040 } 1041 1042 /* Finally initialize convert_triggered flag */ 1043 SLAVE_CONVERT_TRIGGERED(sl) = 0; 1044 1045 return 0; 1046 } 1047 1048 static void w1_therm_remove_slave(struct w1_slave *sl) 1049 { 1050 int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data)); 1051 1052 if (bulk_read_support(sl)) { 1053 bulk_read_device_counter--; 1054 /* Delete the entry if no more device support the feature */ 1055 if (!bulk_read_device_counter) 1056 device_remove_file(&sl->master->dev, 1057 &dev_attr_therm_bulk_read); 1058 } 1059 1060 while (refcnt) { 1061 msleep(1000); 1062 refcnt = atomic_read(THERM_REFCNT(sl->family_data)); 1063 } 1064 kfree(sl->family_data); 1065 sl->family_data = NULL; 1066 } 1067 1068 /* Hardware Functions */ 1069 1070 /* Safe version of reset_select_slave - avoid using the one in w_io.c */ 1071 static int reset_select_slave(struct w1_slave *sl) 1072 { 1073 u8 match[9] = { W1_MATCH_ROM, }; 1074 u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num)); 1075 1076 if (w1_reset_bus(sl->master)) 1077 return -ENODEV; 1078 1079 memcpy(&match[1], &rn, 8); 1080 w1_write_block(sl->master, match, 9); 1081 1082 return 0; 1083 } 1084 1085 /** 1086 * w1_poll_completion - Poll for operation completion, with timeout 1087 * @dev_master: the device master of the bus 1088 * @tout_ms: timeout in milliseconds 1089 * 1090 * The device is answering 0's while an operation is in progress and 1's after it completes 1091 * Timeout may happen if the previous command was not recognised due to a line noise 1092 * 1093 * Return: 0 - OK, negative error - timeout 1094 */ 1095 static int w1_poll_completion(struct w1_master *dev_master, int tout_ms) 1096 { 1097 int i; 1098 1099 for (i = 0; i < tout_ms/W1_POLL_PERIOD; i++) { 1100 /* Delay is before poll, for device to recognize a command */ 1101 msleep(W1_POLL_PERIOD); 1102 1103 /* Compare all 8 bits to mitigate a noise on the bus */ 1104 if (w1_read_8(dev_master) == 0xFF) 1105 break; 1106 } 1107 if (i == tout_ms/W1_POLL_PERIOD) 1108 return -EIO; 1109 1110 return 0; 1111 } 1112 1113 static int convert_t(struct w1_slave *sl, struct therm_info *info) 1114 { 1115 struct w1_master *dev_master = sl->master; 1116 int max_trying = W1_THERM_MAX_TRY; 1117 int t_conv; 1118 int ret = -ENODEV; 1119 bool strong_pullup; 1120 1121 if (!sl->family_data) 1122 goto error; 1123 1124 strong_pullup = (w1_strong_pullup == 2 || 1125 (!SLAVE_POWERMODE(sl) && 1126 w1_strong_pullup)); 1127 1128 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 1129 dev_warn(&sl->dev, 1130 "%s: Disabling W1_THERM_POLL_COMPLETION in parasite power mode.\n", 1131 __func__); 1132 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION; 1133 } 1134 1135 /* get conversion duration device and id dependent */ 1136 t_conv = conversion_time(sl); 1137 1138 memset(info->rom, 0, sizeof(info->rom)); 1139 1140 /* prevent the slave from going away in sleep */ 1141 atomic_inc(THERM_REFCNT(sl->family_data)); 1142 1143 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1144 ret = -EAGAIN; /* Didn't acquire the mutex */ 1145 goto dec_refcnt; 1146 } 1147 1148 while (max_trying-- && ret) { /* ret should be 0 */ 1149 1150 info->verdict = 0; 1151 info->crc = 0; 1152 /* safe version to select slave */ 1153 if (!reset_select_slave(sl)) { 1154 unsigned long sleep_rem; 1155 1156 /* 750ms strong pullup (or delay) after the convert */ 1157 if (strong_pullup) 1158 w1_next_pullup(dev_master, t_conv); 1159 1160 w1_write_8(dev_master, W1_CONVERT_TEMP); 1161 1162 if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 1163 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); 1164 if (ret) { 1165 dev_dbg(&sl->dev, "%s: Timeout\n", __func__); 1166 goto mt_unlock; 1167 } 1168 mutex_unlock(&dev_master->bus_mutex); 1169 } else if (!strong_pullup) { /*no device need pullup */ 1170 sleep_rem = msleep_interruptible(t_conv); 1171 if (sleep_rem != 0) { 1172 ret = -EINTR; 1173 goto mt_unlock; 1174 } 1175 mutex_unlock(&dev_master->bus_mutex); 1176 } else { /*some device need pullup */ 1177 mutex_unlock(&dev_master->bus_mutex); 1178 sleep_rem = msleep_interruptible(t_conv); 1179 if (sleep_rem != 0) { 1180 ret = -EINTR; 1181 goto dec_refcnt; 1182 } 1183 } 1184 ret = read_scratchpad(sl, info); 1185 1186 /* If enabled, check for conversion success */ 1187 if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) && 1188 (info->rom[6] == 0xC) && 1189 ((info->rom[1] == 0x5 && info->rom[0] == 0x50) || 1190 (info->rom[1] == 0x7 && info->rom[0] == 0xFF)) 1191 ) { 1192 /* Invalid reading (scratchpad byte 6 = 0xC) 1193 * due to insufficient conversion time 1194 * or power failure. 1195 */ 1196 ret = -EIO; 1197 } 1198 1199 goto dec_refcnt; 1200 } 1201 1202 } 1203 1204 mt_unlock: 1205 mutex_unlock(&dev_master->bus_mutex); 1206 dec_refcnt: 1207 atomic_dec(THERM_REFCNT(sl->family_data)); 1208 error: 1209 return ret; 1210 } 1211 1212 static int conv_time_measure(struct w1_slave *sl, int *conv_time) 1213 { 1214 struct therm_info inf, 1215 *info = &inf; 1216 struct w1_master *dev_master = sl->master; 1217 int max_trying = W1_THERM_MAX_TRY; 1218 int ret = -ENODEV; 1219 bool strong_pullup; 1220 1221 if (!sl->family_data) 1222 goto error; 1223 1224 strong_pullup = (w1_strong_pullup == 2 || 1225 (!SLAVE_POWERMODE(sl) && 1226 w1_strong_pullup)); 1227 1228 if (strong_pullup) { 1229 pr_info("%s: Measure with strong_pullup is not supported.\n", __func__); 1230 return -EINVAL; 1231 } 1232 1233 memset(info->rom, 0, sizeof(info->rom)); 1234 1235 /* prevent the slave from going away in sleep */ 1236 atomic_inc(THERM_REFCNT(sl->family_data)); 1237 1238 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1239 ret = -EAGAIN; /* Didn't acquire the mutex */ 1240 goto dec_refcnt; 1241 } 1242 1243 while (max_trying-- && ret) { /* ret should be 0 */ 1244 info->verdict = 0; 1245 info->crc = 0; 1246 /* safe version to select slave */ 1247 if (!reset_select_slave(sl)) { 1248 int j_start, j_end; 1249 1250 /*no device need pullup */ 1251 w1_write_8(dev_master, W1_CONVERT_TEMP); 1252 1253 j_start = jiffies; 1254 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP); 1255 if (ret) { 1256 dev_dbg(&sl->dev, "%s: Timeout\n", __func__); 1257 goto mt_unlock; 1258 } 1259 j_end = jiffies; 1260 /* 1.2x increase for variation and changes over temperature range */ 1261 *conv_time = jiffies_to_msecs(j_end-j_start)*12/10; 1262 pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n", 1263 *conv_time, HZ); 1264 if (*conv_time <= CONV_TIME_MEASURE) { 1265 ret = -EIO; 1266 goto mt_unlock; 1267 } 1268 mutex_unlock(&dev_master->bus_mutex); 1269 ret = read_scratchpad(sl, info); 1270 goto dec_refcnt; 1271 } 1272 1273 } 1274 mt_unlock: 1275 mutex_unlock(&dev_master->bus_mutex); 1276 dec_refcnt: 1277 atomic_dec(THERM_REFCNT(sl->family_data)); 1278 error: 1279 return ret; 1280 } 1281 1282 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info) 1283 { 1284 struct w1_master *dev_master = sl->master; 1285 int max_trying = W1_THERM_MAX_TRY; 1286 int ret = -ENODEV; 1287 1288 info->verdict = 0; 1289 1290 if (!sl->family_data) 1291 goto error; 1292 1293 memset(info->rom, 0, sizeof(info->rom)); 1294 1295 /* prevent the slave from going away in sleep */ 1296 atomic_inc(THERM_REFCNT(sl->family_data)); 1297 1298 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1299 ret = -EAGAIN; /* Didn't acquire the mutex */ 1300 goto dec_refcnt; 1301 } 1302 1303 while (max_trying-- && ret) { /* ret should be 0 */ 1304 /* safe version to select slave */ 1305 if (!reset_select_slave(sl)) { 1306 u8 nb_bytes_read; 1307 1308 w1_write_8(dev_master, W1_READ_SCRATCHPAD); 1309 1310 nb_bytes_read = w1_read_block(dev_master, info->rom, 9); 1311 if (nb_bytes_read != 9) { 1312 dev_warn(&sl->dev, 1313 "w1_read_block(): returned %u instead of 9.\n", 1314 nb_bytes_read); 1315 ret = -EIO; 1316 } 1317 1318 info->crc = w1_calc_crc8(info->rom, 8); 1319 1320 if (info->rom[8] == info->crc) { 1321 info->verdict = 1; 1322 ret = 0; 1323 } else 1324 ret = -EIO; /* CRC not checked */ 1325 } 1326 1327 } 1328 mutex_unlock(&dev_master->bus_mutex); 1329 1330 dec_refcnt: 1331 atomic_dec(THERM_REFCNT(sl->family_data)); 1332 error: 1333 return ret; 1334 } 1335 1336 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes) 1337 { 1338 struct w1_master *dev_master = sl->master; 1339 int max_trying = W1_THERM_MAX_TRY; 1340 int ret = -ENODEV; 1341 1342 if (!sl->family_data) 1343 goto error; 1344 1345 /* prevent the slave from going away in sleep */ 1346 atomic_inc(THERM_REFCNT(sl->family_data)); 1347 1348 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1349 ret = -EAGAIN; /* Didn't acquire the mutex */ 1350 goto dec_refcnt; 1351 } 1352 1353 while (max_trying-- && ret) { /* ret should be 0 */ 1354 /* safe version to select slave */ 1355 if (!reset_select_slave(sl)) { 1356 w1_write_8(dev_master, W1_WRITE_SCRATCHPAD); 1357 w1_write_block(dev_master, data, nb_bytes); 1358 ret = 0; 1359 } 1360 } 1361 mutex_unlock(&dev_master->bus_mutex); 1362 1363 dec_refcnt: 1364 atomic_dec(THERM_REFCNT(sl->family_data)); 1365 error: 1366 return ret; 1367 } 1368 1369 static int copy_scratchpad(struct w1_slave *sl) 1370 { 1371 struct w1_master *dev_master = sl->master; 1372 int max_trying = W1_THERM_MAX_TRY; 1373 int t_write, ret = -ENODEV; 1374 bool strong_pullup; 1375 1376 if (!sl->family_data) 1377 goto error; 1378 1379 t_write = W1_THERM_EEPROM_WRITE_DELAY; 1380 strong_pullup = (w1_strong_pullup == 2 || 1381 (!SLAVE_POWERMODE(sl) && 1382 w1_strong_pullup)); 1383 1384 /* prevent the slave from going away in sleep */ 1385 atomic_inc(THERM_REFCNT(sl->family_data)); 1386 1387 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1388 ret = -EAGAIN; /* Didn't acquire the mutex */ 1389 goto dec_refcnt; 1390 } 1391 1392 while (max_trying-- && ret) { /* ret should be 0 */ 1393 /* safe version to select slave */ 1394 if (!reset_select_slave(sl)) { 1395 unsigned long sleep_rem; 1396 1397 /* 10ms strong pullup (or delay) after the convert */ 1398 if (strong_pullup) 1399 w1_next_pullup(dev_master, t_write); 1400 1401 w1_write_8(dev_master, W1_COPY_SCRATCHPAD); 1402 1403 if (strong_pullup) { 1404 sleep_rem = msleep_interruptible(t_write); 1405 if (sleep_rem != 0) { 1406 ret = -EINTR; 1407 goto mt_unlock; 1408 } 1409 } 1410 ret = 0; 1411 } 1412 1413 } 1414 1415 mt_unlock: 1416 mutex_unlock(&dev_master->bus_mutex); 1417 dec_refcnt: 1418 atomic_dec(THERM_REFCNT(sl->family_data)); 1419 error: 1420 return ret; 1421 } 1422 1423 static int recall_eeprom(struct w1_slave *sl) 1424 { 1425 struct w1_master *dev_master = sl->master; 1426 int max_trying = W1_THERM_MAX_TRY; 1427 int ret = -ENODEV; 1428 1429 if (!sl->family_data) 1430 goto error; 1431 1432 /* prevent the slave from going away in sleep */ 1433 atomic_inc(THERM_REFCNT(sl->family_data)); 1434 1435 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1436 ret = -EAGAIN; /* Didn't acquire the mutex */ 1437 goto dec_refcnt; 1438 } 1439 1440 while (max_trying-- && ret) { /* ret should be 0 */ 1441 /* safe version to select slave */ 1442 if (!reset_select_slave(sl)) { 1443 1444 w1_write_8(dev_master, W1_RECALL_EEPROM); 1445 ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM); 1446 } 1447 1448 } 1449 1450 mutex_unlock(&dev_master->bus_mutex); 1451 1452 dec_refcnt: 1453 atomic_dec(THERM_REFCNT(sl->family_data)); 1454 error: 1455 return ret; 1456 } 1457 1458 static int read_powermode(struct w1_slave *sl) 1459 { 1460 struct w1_master *dev_master = sl->master; 1461 int max_trying = W1_THERM_MAX_TRY; 1462 int ret = -ENODEV; 1463 1464 if (!sl->family_data) 1465 goto error; 1466 1467 /* prevent the slave from going away in sleep */ 1468 atomic_inc(THERM_REFCNT(sl->family_data)); 1469 1470 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1471 ret = -EAGAIN; /* Didn't acquire the mutex */ 1472 goto dec_refcnt; 1473 } 1474 1475 while ((max_trying--) && (ret < 0)) { 1476 /* safe version to select slave */ 1477 if (!reset_select_slave(sl)) { 1478 w1_write_8(dev_master, W1_READ_PSUPPLY); 1479 /* 1480 * Emit a read time slot and read only one bit, 1481 * 1 is externally powered, 1482 * 0 is parasite powered 1483 */ 1484 ret = w1_touch_bit(dev_master, 1); 1485 /* ret should be either 1 either 0 */ 1486 } 1487 } 1488 mutex_unlock(&dev_master->bus_mutex); 1489 1490 dec_refcnt: 1491 atomic_dec(THERM_REFCNT(sl->family_data)); 1492 error: 1493 return ret; 1494 } 1495 1496 static int trigger_bulk_read(struct w1_master *dev_master) 1497 { 1498 struct w1_slave *sl = NULL; /* used to iterate through slaves */ 1499 int max_trying = W1_THERM_MAX_TRY; 1500 int t_conv = 0; 1501 int ret = -ENODEV; 1502 bool strong_pullup = false; 1503 1504 /* 1505 * Check whether there are parasite powered device on the bus, 1506 * and compute duration of conversion for these devices 1507 * so we can apply a strong pullup if required 1508 */ 1509 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1510 if (!sl->family_data) 1511 goto error; 1512 if (bulk_read_support(sl)) { 1513 int t_cur = conversion_time(sl); 1514 1515 t_conv = max(t_cur, t_conv); 1516 strong_pullup = strong_pullup || 1517 (w1_strong_pullup == 2 || 1518 (!SLAVE_POWERMODE(sl) && 1519 w1_strong_pullup)); 1520 } 1521 } 1522 1523 /* 1524 * t_conv is the max conversion time required on the bus 1525 * If its 0, no device support the bulk read feature 1526 */ 1527 if (!t_conv) 1528 goto error; 1529 1530 if (!bus_mutex_lock(&dev_master->bus_mutex)) { 1531 ret = -EAGAIN; /* Didn't acquire the mutex */ 1532 goto error; 1533 } 1534 1535 while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */ 1536 1537 if (!w1_reset_bus(dev_master)) { /* Just reset the bus */ 1538 unsigned long sleep_rem; 1539 1540 w1_write_8(dev_master, W1_SKIP_ROM); 1541 1542 if (strong_pullup) /* Apply pullup if required */ 1543 w1_next_pullup(dev_master, t_conv); 1544 1545 w1_write_8(dev_master, W1_CONVERT_TEMP); 1546 1547 /* set a flag to instruct that converT pending */ 1548 list_for_each_entry(sl, 1549 &dev_master->slist, w1_slave_entry) { 1550 if (bulk_read_support(sl)) 1551 SLAVE_CONVERT_TRIGGERED(sl) = -1; 1552 } 1553 1554 if (strong_pullup) { /* some device need pullup */ 1555 sleep_rem = msleep_interruptible(t_conv); 1556 if (sleep_rem != 0) { 1557 ret = -EINTR; 1558 goto mt_unlock; 1559 } 1560 mutex_unlock(&dev_master->bus_mutex); 1561 } else { 1562 mutex_unlock(&dev_master->bus_mutex); 1563 sleep_rem = msleep_interruptible(t_conv); 1564 if (sleep_rem != 0) { 1565 ret = -EINTR; 1566 goto set_flag; 1567 } 1568 } 1569 ret = 0; 1570 goto set_flag; 1571 } 1572 } 1573 1574 mt_unlock: 1575 mutex_unlock(&dev_master->bus_mutex); 1576 set_flag: 1577 /* set a flag to register convsersion is done */ 1578 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1579 if (bulk_read_support(sl)) 1580 SLAVE_CONVERT_TRIGGERED(sl) = 1; 1581 } 1582 error: 1583 return ret; 1584 } 1585 1586 /* Sysfs Interface definition */ 1587 1588 static ssize_t w1_slave_show(struct device *device, 1589 struct device_attribute *attr, char *buf) 1590 { 1591 struct w1_slave *sl = dev_to_w1_slave(device); 1592 struct therm_info info; 1593 u8 *family_data = sl->family_data; 1594 int ret, i; 1595 ssize_t c = PAGE_SIZE; 1596 1597 if (bulk_read_support(sl)) { 1598 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) { 1599 dev_dbg(device, 1600 "%s: Conversion in progress, retry later\n", 1601 __func__); 1602 return 0; 1603 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) { 1604 /* A bulk read has been issued, read the device RAM */ 1605 ret = read_scratchpad(sl, &info); 1606 SLAVE_CONVERT_TRIGGERED(sl) = 0; 1607 } else 1608 ret = convert_t(sl, &info); 1609 } else 1610 ret = convert_t(sl, &info); 1611 1612 if (ret < 0) { 1613 dev_dbg(device, 1614 "%s: Temperature data may be corrupted. err=%d\n", 1615 __func__, ret); 1616 return 0; 1617 } 1618 1619 for (i = 0; i < 9; ++i) 1620 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]); 1621 c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n", 1622 info.crc, (info.verdict) ? "YES" : "NO"); 1623 1624 if (info.verdict) 1625 memcpy(family_data, info.rom, sizeof(info.rom)); 1626 else 1627 dev_warn(device, "%s:Read failed CRC check\n", __func__); 1628 1629 for (i = 0; i < 9; ++i) 1630 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", 1631 ((u8 *)family_data)[i]); 1632 1633 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n", 1634 temperature_from_RAM(sl, info.rom)); 1635 1636 ret = PAGE_SIZE - c; 1637 return ret; 1638 } 1639 1640 static ssize_t w1_slave_store(struct device *device, 1641 struct device_attribute *attr, const char *buf, 1642 size_t size) 1643 { 1644 int val, ret = 0; 1645 struct w1_slave *sl = dev_to_w1_slave(device); 1646 1647 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */ 1648 1649 if (ret) { /* conversion error */ 1650 dev_info(device, 1651 "%s: conversion error. err= %d\n", __func__, ret); 1652 return size; /* return size to avoid call back again */ 1653 } 1654 1655 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1656 dev_info(device, 1657 "%s: Device not supported by the driver\n", __func__); 1658 return size; /* No device family */ 1659 } 1660 1661 if (val == 0) /* val=0 : trigger a EEPROM save */ 1662 ret = copy_scratchpad(sl); 1663 else { 1664 if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution) 1665 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val); 1666 } 1667 1668 if (ret) { 1669 dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret); 1670 /* Propagate error to userspace */ 1671 return ret; 1672 } 1673 SLAVE_RESOLUTION(sl) = val; 1674 /* Reset the conversion time to default - it depends on resolution */ 1675 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT; 1676 1677 return size; /* always return size to avoid infinite calling */ 1678 } 1679 1680 static ssize_t temperature_show(struct device *device, 1681 struct device_attribute *attr, char *buf) 1682 { 1683 struct w1_slave *sl = dev_to_w1_slave(device); 1684 struct therm_info info; 1685 int ret = 0; 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 if (bulk_read_support(sl)) { 1694 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) { 1695 dev_dbg(device, 1696 "%s: Conversion in progress, retry later\n", 1697 __func__); 1698 return 0; 1699 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) { 1700 /* A bulk read has been issued, read the device RAM */ 1701 ret = read_scratchpad(sl, &info); 1702 SLAVE_CONVERT_TRIGGERED(sl) = 0; 1703 } else 1704 ret = convert_t(sl, &info); 1705 } else 1706 ret = convert_t(sl, &info); 1707 1708 if (ret < 0) { 1709 dev_dbg(device, 1710 "%s: Temperature data may be corrupted. err=%d\n", 1711 __func__, ret); 1712 return 0; 1713 } 1714 1715 return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom)); 1716 } 1717 1718 static ssize_t ext_power_show(struct device *device, 1719 struct device_attribute *attr, char *buf) 1720 { 1721 struct w1_slave *sl = dev_to_w1_slave(device); 1722 1723 if (!sl->family_data) { 1724 dev_info(device, 1725 "%s: Device not supported by the driver\n", __func__); 1726 return 0; /* No device family */ 1727 } 1728 1729 /* Getting the power mode of the device {external, parasite} */ 1730 SLAVE_POWERMODE(sl) = read_powermode(sl); 1731 1732 if (SLAVE_POWERMODE(sl) < 0) { 1733 dev_dbg(device, 1734 "%s: Power_mode may be corrupted. err=%d\n", 1735 __func__, SLAVE_POWERMODE(sl)); 1736 } 1737 return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl)); 1738 } 1739 1740 static ssize_t resolution_show(struct device *device, 1741 struct device_attribute *attr, char *buf) 1742 { 1743 struct w1_slave *sl = dev_to_w1_slave(device); 1744 1745 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1746 dev_info(device, 1747 "%s: Device not supported by the driver\n", __func__); 1748 return 0; /* No device family */ 1749 } 1750 1751 /* get the correct function depending on the device */ 1752 SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl); 1753 if (SLAVE_RESOLUTION(sl) < 0) { 1754 dev_dbg(device, 1755 "%s: Resolution may be corrupted. err=%d\n", 1756 __func__, SLAVE_RESOLUTION(sl)); 1757 } 1758 1759 return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl)); 1760 } 1761 1762 static ssize_t resolution_store(struct device *device, 1763 struct device_attribute *attr, const char *buf, size_t size) 1764 { 1765 struct w1_slave *sl = dev_to_w1_slave(device); 1766 int val; 1767 int ret = 0; 1768 1769 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */ 1770 1771 if (ret) { /* conversion error */ 1772 dev_info(device, 1773 "%s: conversion error. err= %d\n", __func__, ret); 1774 return size; /* return size to avoid call back again */ 1775 } 1776 1777 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1778 dev_info(device, 1779 "%s: Device not supported by the driver\n", __func__); 1780 return size; /* No device family */ 1781 } 1782 1783 /* 1784 * Don't deal with the val enterd by user, 1785 * only device knows what is correct or not 1786 */ 1787 1788 /* get the correct function depending on the device */ 1789 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val); 1790 1791 if (ret) 1792 return ret; 1793 1794 SLAVE_RESOLUTION(sl) = val; 1795 /* Reset the conversion time to default because it depends on resolution */ 1796 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT; 1797 1798 return size; 1799 } 1800 1801 static ssize_t eeprom_cmd_store(struct device *device, 1802 struct device_attribute *attr, const char *buf, size_t size) 1803 { 1804 struct w1_slave *sl = dev_to_w1_slave(device); 1805 int ret = -EINVAL; /* Invalid argument */ 1806 1807 if (size == sizeof(EEPROM_CMD_WRITE)) { 1808 if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1)) 1809 ret = copy_scratchpad(sl); 1810 } else if (size == sizeof(EEPROM_CMD_READ)) { 1811 if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1)) 1812 ret = recall_eeprom(sl); 1813 } 1814 1815 if (ret) 1816 dev_info(device, "%s: error in process %d\n", __func__, ret); 1817 1818 return size; 1819 } 1820 1821 static ssize_t alarms_show(struct device *device, 1822 struct device_attribute *attr, char *buf) 1823 { 1824 struct w1_slave *sl = dev_to_w1_slave(device); 1825 int ret; 1826 s8 th = 0, tl = 0; 1827 struct therm_info scratchpad; 1828 1829 ret = read_scratchpad(sl, &scratchpad); 1830 1831 if (!ret) { 1832 th = scratchpad.rom[2]; /* TH is byte 2 */ 1833 tl = scratchpad.rom[3]; /* TL is byte 3 */ 1834 } else { 1835 dev_info(device, 1836 "%s: error reading alarms register %d\n", 1837 __func__, ret); 1838 } 1839 1840 return sprintf(buf, "%hd %hd\n", tl, th); 1841 } 1842 1843 static ssize_t alarms_store(struct device *device, 1844 struct device_attribute *attr, const char *buf, size_t size) 1845 { 1846 struct w1_slave *sl = dev_to_w1_slave(device); 1847 struct therm_info info; 1848 u8 new_config_register[3]; /* array of data to be written */ 1849 int temp, ret; 1850 char *token = NULL; 1851 s8 tl, th; /* 1 byte per value + temp ring order */ 1852 char *p_args, *orig; 1853 1854 p_args = orig = kmalloc(size, GFP_KERNEL); 1855 /* Safe string copys as buf is const */ 1856 if (!p_args) { 1857 dev_warn(device, 1858 "%s: error unable to allocate memory %d\n", 1859 __func__, -ENOMEM); 1860 return size; 1861 } 1862 strcpy(p_args, buf); 1863 1864 /* Split string using space char */ 1865 token = strsep(&p_args, " "); 1866 1867 if (!token) { 1868 dev_info(device, 1869 "%s: error parsing args %d\n", __func__, -EINVAL); 1870 goto free_m; 1871 } 1872 1873 /* Convert 1st entry to int */ 1874 ret = kstrtoint (token, 10, &temp); 1875 if (ret) { 1876 dev_info(device, 1877 "%s: error parsing args %d\n", __func__, ret); 1878 goto free_m; 1879 } 1880 1881 tl = int_to_short(temp); 1882 1883 /* Split string using space char */ 1884 token = strsep(&p_args, " "); 1885 if (!token) { 1886 dev_info(device, 1887 "%s: error parsing args %d\n", __func__, -EINVAL); 1888 goto free_m; 1889 } 1890 /* Convert 2nd entry to int */ 1891 ret = kstrtoint (token, 10, &temp); 1892 if (ret) { 1893 dev_info(device, 1894 "%s: error parsing args %d\n", __func__, ret); 1895 goto free_m; 1896 } 1897 1898 /* Prepare to cast to short by eliminating out of range values */ 1899 th = int_to_short(temp); 1900 1901 /* Reorder if required th and tl */ 1902 if (tl > th) 1903 swap(tl, th); 1904 1905 /* 1906 * Read the scratchpad to change only the required bits 1907 * (th : byte 2 - tl: byte 3) 1908 */ 1909 ret = read_scratchpad(sl, &info); 1910 if (!ret) { 1911 new_config_register[0] = th; /* Byte 2 */ 1912 new_config_register[1] = tl; /* Byte 3 */ 1913 new_config_register[2] = info.rom[4];/* Byte 4 */ 1914 } else { 1915 dev_info(device, 1916 "%s: error reading from the slave device %d\n", 1917 __func__, ret); 1918 goto free_m; 1919 } 1920 1921 /* Write data in the device RAM */ 1922 if (!SLAVE_SPECIFIC_FUNC(sl)) { 1923 dev_info(device, 1924 "%s: Device not supported by the driver %d\n", 1925 __func__, -ENODEV); 1926 goto free_m; 1927 } 1928 1929 ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register); 1930 if (ret) 1931 dev_info(device, 1932 "%s: error writing to the slave device %d\n", 1933 __func__, ret); 1934 1935 free_m: 1936 /* free allocated memory */ 1937 kfree(orig); 1938 1939 return size; 1940 } 1941 1942 static ssize_t therm_bulk_read_store(struct device *device, 1943 struct device_attribute *attr, const char *buf, size_t size) 1944 { 1945 struct w1_master *dev_master = dev_to_w1_master(device); 1946 int ret = -EINVAL; /* Invalid argument */ 1947 1948 if (size == sizeof(BULK_TRIGGER_CMD)) 1949 if (!strncmp(buf, BULK_TRIGGER_CMD, 1950 sizeof(BULK_TRIGGER_CMD)-1)) 1951 ret = trigger_bulk_read(dev_master); 1952 1953 if (ret) 1954 dev_info(device, 1955 "%s: unable to trigger a bulk read on the bus. err=%d\n", 1956 __func__, ret); 1957 1958 return size; 1959 } 1960 1961 static ssize_t therm_bulk_read_show(struct device *device, 1962 struct device_attribute *attr, char *buf) 1963 { 1964 struct w1_master *dev_master = dev_to_w1_master(device); 1965 struct w1_slave *sl = NULL; 1966 int ret = 0; 1967 1968 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) { 1969 if (sl->family_data) { 1970 if (bulk_read_support(sl)) { 1971 if (SLAVE_CONVERT_TRIGGERED(sl) == -1) { 1972 ret = -1; 1973 goto show_result; 1974 } 1975 if (SLAVE_CONVERT_TRIGGERED(sl) == 1) 1976 /* continue to check other slaves */ 1977 ret = 1; 1978 } 1979 } 1980 } 1981 show_result: 1982 return sprintf(buf, "%d\n", ret); 1983 } 1984 1985 static ssize_t conv_time_show(struct device *device, 1986 struct device_attribute *attr, char *buf) 1987 { 1988 struct w1_slave *sl = dev_to_w1_slave(device); 1989 1990 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 1991 dev_info(device, 1992 "%s: Device is not supported by the driver\n", __func__); 1993 return 0; /* No device family */ 1994 } 1995 return sprintf(buf, "%d\n", conversion_time(sl)); 1996 } 1997 1998 static ssize_t conv_time_store(struct device *device, 1999 struct device_attribute *attr, const char *buf, size_t size) 2000 { 2001 int val, ret = 0; 2002 struct w1_slave *sl = dev_to_w1_slave(device); 2003 2004 if (kstrtoint(buf, 10, &val)) /* converting user entry to int */ 2005 return -EINVAL; 2006 2007 if (check_family_data(sl)) 2008 return -ENODEV; 2009 2010 if (val != CONV_TIME_MEASURE) { 2011 if (val >= CONV_TIME_DEFAULT) 2012 SLAVE_CONV_TIME_OVERRIDE(sl) = val; 2013 else 2014 return -EINVAL; 2015 2016 } else { 2017 int conv_time; 2018 2019 ret = conv_time_measure(sl, &conv_time); 2020 if (ret) 2021 return -EIO; 2022 SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time; 2023 } 2024 return size; 2025 } 2026 2027 static ssize_t features_show(struct device *device, 2028 struct device_attribute *attr, char *buf) 2029 { 2030 struct w1_slave *sl = dev_to_w1_slave(device); 2031 2032 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 2033 dev_info(device, 2034 "%s: Device not supported by the driver\n", __func__); 2035 return 0; /* No device family */ 2036 } 2037 return sprintf(buf, "%u\n", SLAVE_FEATURES(sl)); 2038 } 2039 2040 static ssize_t features_store(struct device *device, 2041 struct device_attribute *attr, const char *buf, size_t size) 2042 { 2043 int val, ret = 0; 2044 bool strong_pullup; 2045 struct w1_slave *sl = dev_to_w1_slave(device); 2046 2047 ret = kstrtouint(buf, 10, &val); /* converting user entry to int */ 2048 if (ret) 2049 return -EINVAL; /* invalid number */ 2050 2051 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) { 2052 dev_info(device, "%s: Device not supported by the driver\n", __func__); 2053 return -ENODEV; 2054 } 2055 2056 if ((val & W1_THERM_FEATURES_MASK) != val) 2057 return -EINVAL; 2058 2059 SLAVE_FEATURES(sl) = val; 2060 2061 strong_pullup = (w1_strong_pullup == 2 || 2062 (!SLAVE_POWERMODE(sl) && 2063 w1_strong_pullup)); 2064 2065 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) { 2066 dev_warn(&sl->dev, 2067 "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n", 2068 __func__); 2069 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION; 2070 } 2071 2072 return size; 2073 } 2074 2075 #if IS_REACHABLE(CONFIG_HWMON) 2076 static int w1_read_temp(struct device *device, u32 attr, int channel, 2077 long *val) 2078 { 2079 struct w1_slave *sl = dev_get_drvdata(device); 2080 struct therm_info info; 2081 int ret; 2082 2083 switch (attr) { 2084 case hwmon_temp_input: 2085 ret = convert_t(sl, &info); 2086 if (ret) 2087 return ret; 2088 2089 if (!info.verdict) { 2090 ret = -EIO; 2091 return ret; 2092 } 2093 2094 *val = temperature_from_RAM(sl, info.rom); 2095 ret = 0; 2096 break; 2097 default: 2098 ret = -EOPNOTSUPP; 2099 break; 2100 } 2101 2102 return ret; 2103 } 2104 #endif 2105 2106 #define W1_42_CHAIN 0x99 2107 #define W1_42_CHAIN_OFF 0x3C 2108 #define W1_42_CHAIN_OFF_INV 0xC3 2109 #define W1_42_CHAIN_ON 0x5A 2110 #define W1_42_CHAIN_ON_INV 0xA5 2111 #define W1_42_CHAIN_DONE 0x96 2112 #define W1_42_CHAIN_DONE_INV 0x69 2113 #define W1_42_COND_READ 0x0F 2114 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA 2115 #define W1_42_FINISHED_BYTE 0xFF 2116 static ssize_t w1_seq_show(struct device *device, 2117 struct device_attribute *attr, char *buf) 2118 { 2119 struct w1_slave *sl = dev_to_w1_slave(device); 2120 ssize_t c = PAGE_SIZE; 2121 int i; 2122 u8 ack; 2123 u64 rn; 2124 struct w1_reg_num *reg_num; 2125 int seq = 0; 2126 2127 mutex_lock(&sl->master->bus_mutex); 2128 /* Place all devices in CHAIN state */ 2129 if (w1_reset_bus(sl->master)) 2130 goto error; 2131 w1_write_8(sl->master, W1_SKIP_ROM); 2132 w1_write_8(sl->master, W1_42_CHAIN); 2133 w1_write_8(sl->master, W1_42_CHAIN_ON); 2134 w1_write_8(sl->master, W1_42_CHAIN_ON_INV); 2135 msleep(sl->master->pullup_duration); 2136 2137 /* check for acknowledgment */ 2138 ack = w1_read_8(sl->master); 2139 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2140 goto error; 2141 2142 /* In case the bus fails to send 0xFF, limit */ 2143 for (i = 0; i <= 64; i++) { 2144 if (w1_reset_bus(sl->master)) 2145 goto error; 2146 2147 w1_write_8(sl->master, W1_42_COND_READ); 2148 w1_read_block(sl->master, (u8 *)&rn, 8); 2149 reg_num = (struct w1_reg_num *) &rn; 2150 if (reg_num->family == W1_42_FINISHED_BYTE) 2151 break; 2152 if (sl->reg_num.id == reg_num->id) 2153 seq = i; 2154 2155 if (w1_reset_bus(sl->master)) 2156 goto error; 2157 2158 /* Put the device into chain DONE state */ 2159 w1_write_8(sl->master, W1_MATCH_ROM); 2160 w1_write_block(sl->master, (u8 *)&rn, 8); 2161 w1_write_8(sl->master, W1_42_CHAIN); 2162 w1_write_8(sl->master, W1_42_CHAIN_DONE); 2163 w1_write_8(sl->master, W1_42_CHAIN_DONE_INV); 2164 2165 /* check for acknowledgment */ 2166 ack = w1_read_8(sl->master); 2167 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2168 goto error; 2169 } 2170 2171 /* Exit from CHAIN state */ 2172 if (w1_reset_bus(sl->master)) 2173 goto error; 2174 w1_write_8(sl->master, W1_SKIP_ROM); 2175 w1_write_8(sl->master, W1_42_CHAIN); 2176 w1_write_8(sl->master, W1_42_CHAIN_OFF); 2177 w1_write_8(sl->master, W1_42_CHAIN_OFF_INV); 2178 2179 /* check for acknowledgment */ 2180 ack = w1_read_8(sl->master); 2181 if (ack != W1_42_SUCCESS_CONFIRM_BYTE) 2182 goto error; 2183 mutex_unlock(&sl->master->bus_mutex); 2184 2185 c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq); 2186 return PAGE_SIZE - c; 2187 error: 2188 mutex_unlock(&sl->master->bus_mutex); 2189 return -EIO; 2190 } 2191 2192 static int __init w1_therm_init(void) 2193 { 2194 int err, i; 2195 2196 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) { 2197 err = w1_register_family(w1_therm_families[i].f); 2198 if (err) 2199 w1_therm_families[i].broken = 1; 2200 } 2201 2202 return 0; 2203 } 2204 2205 static void __exit w1_therm_fini(void) 2206 { 2207 int i; 2208 2209 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) 2210 if (!w1_therm_families[i].broken) 2211 w1_unregister_family(w1_therm_families[i].f); 2212 } 2213 2214 module_init(w1_therm_init); 2215 module_exit(w1_therm_fini); 2216 2217 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); 2218 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family."); 2219 MODULE_LICENSE("GPL"); 2220 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20)); 2221 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822)); 2222 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20)); 2223 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825)); 2224 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00)); 2225