1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias. 4 * 5 * Copyright (C) 2015, Intel Corp. 6 * Author: Mika Westerberg <mika.westerberg@linux.intel.com> 7 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 8 * 9 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 10 * 11 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 12 */ 13 14 #include <linux/acpi.h> 15 #include <linux/device.h> 16 #include <linux/export.h> 17 #include <linux/nls.h> 18 19 #include "internal.h" 20 21 static ssize_t acpi_object_path(acpi_handle handle, char *buf) 22 { 23 struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL}; 24 int result; 25 26 result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path); 27 if (result) 28 return result; 29 30 result = sprintf(buf, "%s\n", (char *)path.pointer); 31 kfree(path.pointer); 32 return result; 33 } 34 35 struct acpi_data_node_attr { 36 struct attribute attr; 37 ssize_t (*show)(struct acpi_data_node *, char *); 38 ssize_t (*store)(struct acpi_data_node *, const char *, size_t count); 39 }; 40 41 #define DATA_NODE_ATTR(_name) \ 42 static struct acpi_data_node_attr data_node_##_name = \ 43 __ATTR(_name, 0444, data_node_show_##_name, NULL) 44 45 static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf) 46 { 47 return dn->handle ? acpi_object_path(dn->handle, buf) : 0; 48 } 49 50 DATA_NODE_ATTR(path); 51 52 static struct attribute *acpi_data_node_default_attrs[] = { 53 &data_node_path.attr, 54 NULL 55 }; 56 ATTRIBUTE_GROUPS(acpi_data_node_default); 57 58 #define to_data_node(k) container_of(k, struct acpi_data_node, kobj) 59 #define to_attr(a) container_of(a, struct acpi_data_node_attr, attr) 60 61 static ssize_t acpi_data_node_attr_show(struct kobject *kobj, 62 struct attribute *attr, char *buf) 63 { 64 struct acpi_data_node *dn = to_data_node(kobj); 65 struct acpi_data_node_attr *dn_attr = to_attr(attr); 66 67 return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO; 68 } 69 70 static const struct sysfs_ops acpi_data_node_sysfs_ops = { 71 .show = acpi_data_node_attr_show, 72 }; 73 74 static void acpi_data_node_release(struct kobject *kobj) 75 { 76 struct acpi_data_node *dn = to_data_node(kobj); 77 78 complete(&dn->kobj_done); 79 } 80 81 static const struct kobj_type acpi_data_node_ktype = { 82 .sysfs_ops = &acpi_data_node_sysfs_ops, 83 .default_groups = acpi_data_node_default_groups, 84 .release = acpi_data_node_release, 85 }; 86 87 static void acpi_expose_nondev_subnodes(struct kobject *kobj, 88 struct acpi_device_data *data) 89 { 90 struct list_head *list = &data->subnodes; 91 struct acpi_data_node *dn; 92 93 if (list_empty(list)) 94 return; 95 96 list_for_each_entry(dn, list, sibling) { 97 int ret; 98 99 init_completion(&dn->kobj_done); 100 ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype, 101 kobj, "%s", dn->name); 102 if (!ret) 103 acpi_expose_nondev_subnodes(&dn->kobj, &dn->data); 104 else if (dn->handle) 105 acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret); 106 } 107 } 108 109 static void acpi_hide_nondev_subnodes(struct acpi_device_data *data) 110 { 111 struct list_head *list = &data->subnodes; 112 struct acpi_data_node *dn; 113 114 if (list_empty(list)) 115 return; 116 117 list_for_each_entry_reverse(dn, list, sibling) { 118 acpi_hide_nondev_subnodes(&dn->data); 119 kobject_put(&dn->kobj); 120 } 121 } 122 123 /** 124 * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent 125 * @acpi_dev: ACPI device object. 126 * @modalias: Buffer to print into. 127 * @size: Size of the buffer. 128 * 129 * Creates hid/cid(s) string needed for modalias and uevent 130 * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get: 131 * char *modalias: "acpi:IBM0001:ACPI0001" 132 * Return: 0: no _HID and no _CID 133 * -EINVAL: output error 134 * -ENOMEM: output is truncated 135 */ 136 static int create_pnp_modalias(const struct acpi_device *acpi_dev, char *modalias, 137 int size) 138 { 139 int len; 140 int count; 141 struct acpi_hardware_id *id; 142 143 /* Avoid unnecessarily loading modules for non present devices. */ 144 if (!acpi_device_is_present(acpi_dev)) 145 return 0; 146 147 /* 148 * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should 149 * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the 150 * device's list. 151 */ 152 count = 0; 153 list_for_each_entry(id, &acpi_dev->pnp.ids, list) 154 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID)) 155 count++; 156 157 if (!count) 158 return 0; 159 160 len = snprintf(modalias, size, "acpi:"); 161 if (len >= size) 162 return -ENOMEM; 163 164 size -= len; 165 166 list_for_each_entry(id, &acpi_dev->pnp.ids, list) { 167 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID)) 168 continue; 169 170 count = snprintf(&modalias[len], size, "%s:", id->id); 171 172 if (count >= size) 173 return -ENOMEM; 174 175 len += count; 176 size -= count; 177 } 178 179 return len; 180 } 181 182 /** 183 * create_of_modalias - Creates DT compatible string for modalias and uevent 184 * @acpi_dev: ACPI device object. 185 * @modalias: Buffer to print into. 186 * @size: Size of the buffer. 187 * 188 * Expose DT compatible modalias as of:NnameTCcompatible. This function should 189 * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of 190 * ACPI/PNP IDs. 191 */ 192 static int create_of_modalias(const struct acpi_device *acpi_dev, char *modalias, 193 int size) 194 { 195 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 196 const union acpi_object *of_compatible, *obj; 197 acpi_status status; 198 int len, count; 199 int i, nval; 200 char *c; 201 202 status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf); 203 if (ACPI_FAILURE(status)) 204 return -ENODEV; 205 206 /* DT strings are all in lower case */ 207 for (c = buf.pointer; *c != '\0'; c++) 208 *c = tolower(*c); 209 210 len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer); 211 ACPI_FREE(buf.pointer); 212 213 if (len >= size) 214 return -ENOMEM; 215 216 size -= len; 217 218 of_compatible = acpi_dev->data.of_compatible; 219 if (of_compatible->type == ACPI_TYPE_PACKAGE) { 220 nval = of_compatible->package.count; 221 obj = of_compatible->package.elements; 222 } else { /* Must be ACPI_TYPE_STRING. */ 223 nval = 1; 224 obj = of_compatible; 225 } 226 for (i = 0; i < nval; i++, obj++) { 227 count = snprintf(&modalias[len], size, "C%s", 228 obj->string.pointer); 229 230 if (count >= size) 231 return -ENOMEM; 232 233 len += count; 234 size -= count; 235 } 236 237 return len; 238 } 239 240 int __acpi_device_uevent_modalias(const struct acpi_device *adev, 241 struct kobj_uevent_env *env) 242 { 243 int len; 244 245 if (!adev) 246 return -ENODEV; 247 248 if (list_empty(&adev->pnp.ids)) 249 return 0; 250 251 if (add_uevent_var(env, "MODALIAS=")) 252 return -ENOMEM; 253 254 if (adev->data.of_compatible) 255 len = create_of_modalias(adev, &env->buf[env->buflen - 1], 256 sizeof(env->buf) - env->buflen); 257 else 258 len = create_pnp_modalias(adev, &env->buf[env->buflen - 1], 259 sizeof(env->buf) - env->buflen); 260 if (len < 0) 261 return len; 262 263 env->buflen += len; 264 265 return 0; 266 } 267 268 /** 269 * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices. 270 * @dev: Struct device to get ACPI device node. 271 * @env: Environment variables of the kobject uevent. 272 * 273 * Create the uevent modalias field for ACPI-enumerated devices. 274 * 275 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with 276 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001". 277 */ 278 int acpi_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env) 279 { 280 return __acpi_device_uevent_modalias(acpi_companion_match(dev), env); 281 } 282 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias); 283 284 static int __acpi_device_modalias(const struct acpi_device *adev, char *buf, int size) 285 { 286 int len, count; 287 288 if (!adev) 289 return -ENODEV; 290 291 if (list_empty(&adev->pnp.ids)) 292 return 0; 293 294 len = create_pnp_modalias(adev, buf, size - 1); 295 if (len < 0) { 296 return len; 297 } else if (len > 0) { 298 buf[len++] = '\n'; 299 size -= len; 300 } 301 if (!adev->data.of_compatible) 302 return len; 303 304 count = create_of_modalias(adev, buf + len, size - 1); 305 if (count < 0) { 306 return count; 307 } else if (count > 0) { 308 len += count; 309 buf[len++] = '\n'; 310 } 311 312 return len; 313 } 314 315 /** 316 * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices. 317 * @dev: Struct device to get ACPI device node. 318 * @buf: The buffer to save pnp_modalias and of_modalias. 319 * @size: Size of buffer. 320 * 321 * Create the modalias sysfs attribute for ACPI-enumerated devices. 322 * 323 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with 324 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001". 325 */ 326 int acpi_device_modalias(struct device *dev, char *buf, int size) 327 { 328 return __acpi_device_modalias(acpi_companion_match(dev), buf, size); 329 } 330 EXPORT_SYMBOL_GPL(acpi_device_modalias); 331 332 static ssize_t 333 modalias_show(struct device *dev, struct device_attribute *attr, char *buf) 334 { 335 return __acpi_device_modalias(to_acpi_device(dev), buf, 1024); 336 } 337 static DEVICE_ATTR_RO(modalias); 338 339 static ssize_t real_power_state_show(struct device *dev, 340 struct device_attribute *attr, char *buf) 341 { 342 struct acpi_device *adev = to_acpi_device(dev); 343 int state; 344 int ret; 345 346 ret = acpi_device_get_power(adev, &state); 347 if (ret) 348 return ret; 349 350 return sprintf(buf, "%s\n", acpi_power_state_string(state)); 351 } 352 353 static DEVICE_ATTR_RO(real_power_state); 354 355 static ssize_t power_state_show(struct device *dev, 356 struct device_attribute *attr, char *buf) 357 { 358 struct acpi_device *adev = to_acpi_device(dev); 359 360 return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state)); 361 } 362 363 static DEVICE_ATTR_RO(power_state); 364 365 static ssize_t 366 eject_store(struct device *d, struct device_attribute *attr, 367 const char *buf, size_t count) 368 { 369 struct acpi_device *acpi_device = to_acpi_device(d); 370 acpi_object_type not_used; 371 acpi_status status; 372 373 if (!count || buf[0] != '1') 374 return -EINVAL; 375 376 if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled) 377 && !d->driver) 378 return -ENODEV; 379 380 status = acpi_get_type(acpi_device->handle, ¬_used); 381 if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable) 382 return -ENODEV; 383 384 acpi_dev_get(acpi_device); 385 status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT); 386 if (ACPI_SUCCESS(status)) 387 return count; 388 389 acpi_dev_put(acpi_device); 390 acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT, 391 ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL); 392 return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN; 393 } 394 395 static DEVICE_ATTR_WO(eject); 396 397 static ssize_t 398 hid_show(struct device *dev, struct device_attribute *attr, char *buf) 399 { 400 struct acpi_device *acpi_dev = to_acpi_device(dev); 401 402 return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev)); 403 } 404 static DEVICE_ATTR_RO(hid); 405 406 static ssize_t uid_show(struct device *dev, 407 struct device_attribute *attr, char *buf) 408 { 409 struct acpi_device *acpi_dev = to_acpi_device(dev); 410 411 return sprintf(buf, "%s\n", acpi_device_uid(acpi_dev)); 412 } 413 static DEVICE_ATTR_RO(uid); 414 415 static ssize_t adr_show(struct device *dev, 416 struct device_attribute *attr, char *buf) 417 { 418 struct acpi_device *acpi_dev = to_acpi_device(dev); 419 420 if (acpi_dev->pnp.bus_address > U32_MAX) 421 return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address); 422 else 423 return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address); 424 } 425 static DEVICE_ATTR_RO(adr); 426 427 static ssize_t path_show(struct device *dev, 428 struct device_attribute *attr, char *buf) 429 { 430 struct acpi_device *acpi_dev = to_acpi_device(dev); 431 432 return acpi_object_path(acpi_dev->handle, buf); 433 } 434 static DEVICE_ATTR_RO(path); 435 436 /* sysfs file that shows description text from the ACPI _STR method */ 437 static ssize_t description_show(struct device *dev, 438 struct device_attribute *attr, 439 char *buf) 440 { 441 struct acpi_device *acpi_dev = to_acpi_device(dev); 442 int result; 443 444 if (acpi_dev->pnp.str_obj == NULL) 445 return 0; 446 447 /* 448 * The _STR object contains a Unicode identifier for a device. 449 * We need to convert to utf-8 so it can be displayed. 450 */ 451 result = utf16s_to_utf8s( 452 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer, 453 acpi_dev->pnp.str_obj->buffer.length, 454 UTF16_LITTLE_ENDIAN, buf, 455 PAGE_SIZE - 1); 456 457 buf[result++] = '\n'; 458 459 return result; 460 } 461 static DEVICE_ATTR_RO(description); 462 463 static ssize_t 464 sun_show(struct device *dev, struct device_attribute *attr, 465 char *buf) 466 { 467 struct acpi_device *acpi_dev = to_acpi_device(dev); 468 acpi_status status; 469 unsigned long long sun; 470 471 status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun); 472 if (ACPI_FAILURE(status)) 473 return -EIO; 474 475 return sprintf(buf, "%llu\n", sun); 476 } 477 static DEVICE_ATTR_RO(sun); 478 479 static ssize_t 480 hrv_show(struct device *dev, struct device_attribute *attr, 481 char *buf) 482 { 483 struct acpi_device *acpi_dev = to_acpi_device(dev); 484 acpi_status status; 485 unsigned long long hrv; 486 487 status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv); 488 if (ACPI_FAILURE(status)) 489 return -EIO; 490 491 return sprintf(buf, "%llu\n", hrv); 492 } 493 static DEVICE_ATTR_RO(hrv); 494 495 static ssize_t status_show(struct device *dev, struct device_attribute *attr, 496 char *buf) 497 { 498 struct acpi_device *acpi_dev = to_acpi_device(dev); 499 acpi_status status; 500 unsigned long long sta; 501 502 status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta); 503 if (ACPI_FAILURE(status)) 504 return -EIO; 505 506 return sprintf(buf, "%llu\n", sta); 507 } 508 static DEVICE_ATTR_RO(status); 509 510 /** 511 * acpi_device_setup_files - Create sysfs attributes of an ACPI device. 512 * @dev: ACPI device object. 513 */ 514 int acpi_device_setup_files(struct acpi_device *dev) 515 { 516 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; 517 acpi_status status; 518 int result = 0; 519 520 /* 521 * Devices gotten from FADT don't have a "path" attribute 522 */ 523 if (dev->handle) { 524 result = device_create_file(&dev->dev, &dev_attr_path); 525 if (result) 526 goto end; 527 } 528 529 if (!list_empty(&dev->pnp.ids)) { 530 result = device_create_file(&dev->dev, &dev_attr_hid); 531 if (result) 532 goto end; 533 534 result = device_create_file(&dev->dev, &dev_attr_modalias); 535 if (result) 536 goto end; 537 } 538 539 /* 540 * If device has _STR, 'description' file is created 541 */ 542 if (acpi_has_method(dev->handle, "_STR")) { 543 status = acpi_evaluate_object(dev->handle, "_STR", 544 NULL, &buffer); 545 if (ACPI_FAILURE(status)) 546 buffer.pointer = NULL; 547 dev->pnp.str_obj = buffer.pointer; 548 result = device_create_file(&dev->dev, &dev_attr_description); 549 if (result) 550 goto end; 551 } 552 553 if (dev->pnp.type.bus_address) 554 result = device_create_file(&dev->dev, &dev_attr_adr); 555 if (acpi_device_uid(dev)) 556 result = device_create_file(&dev->dev, &dev_attr_uid); 557 558 if (acpi_has_method(dev->handle, "_SUN")) { 559 result = device_create_file(&dev->dev, &dev_attr_sun); 560 if (result) 561 goto end; 562 } 563 564 if (acpi_has_method(dev->handle, "_HRV")) { 565 result = device_create_file(&dev->dev, &dev_attr_hrv); 566 if (result) 567 goto end; 568 } 569 570 if (acpi_has_method(dev->handle, "_STA")) { 571 result = device_create_file(&dev->dev, &dev_attr_status); 572 if (result) 573 goto end; 574 } 575 576 /* 577 * If device has _EJ0, 'eject' file is created that is used to trigger 578 * hot-removal function from userland. 579 */ 580 if (acpi_has_method(dev->handle, "_EJ0")) { 581 result = device_create_file(&dev->dev, &dev_attr_eject); 582 if (result) 583 return result; 584 } 585 586 if (dev->flags.power_manageable) { 587 result = device_create_file(&dev->dev, &dev_attr_power_state); 588 if (result) 589 return result; 590 591 if (dev->power.flags.power_resources) 592 result = device_create_file(&dev->dev, 593 &dev_attr_real_power_state); 594 } 595 596 acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data); 597 598 end: 599 return result; 600 } 601 602 /** 603 * acpi_device_remove_files - Remove sysfs attributes of an ACPI device. 604 * @dev: ACPI device object. 605 */ 606 void acpi_device_remove_files(struct acpi_device *dev) 607 { 608 acpi_hide_nondev_subnodes(&dev->data); 609 610 if (dev->flags.power_manageable) { 611 device_remove_file(&dev->dev, &dev_attr_power_state); 612 if (dev->power.flags.power_resources) 613 device_remove_file(&dev->dev, 614 &dev_attr_real_power_state); 615 } 616 617 /* 618 * If device has _STR, remove 'description' file 619 */ 620 if (acpi_has_method(dev->handle, "_STR")) { 621 kfree(dev->pnp.str_obj); 622 device_remove_file(&dev->dev, &dev_attr_description); 623 } 624 /* 625 * If device has _EJ0, remove 'eject' file. 626 */ 627 if (acpi_has_method(dev->handle, "_EJ0")) 628 device_remove_file(&dev->dev, &dev_attr_eject); 629 630 if (acpi_has_method(dev->handle, "_SUN")) 631 device_remove_file(&dev->dev, &dev_attr_sun); 632 633 if (acpi_has_method(dev->handle, "_HRV")) 634 device_remove_file(&dev->dev, &dev_attr_hrv); 635 636 if (acpi_device_uid(dev)) 637 device_remove_file(&dev->dev, &dev_attr_uid); 638 if (dev->pnp.type.bus_address) 639 device_remove_file(&dev->dev, &dev_attr_adr); 640 device_remove_file(&dev->dev, &dev_attr_modalias); 641 device_remove_file(&dev->dev, &dev_attr_hid); 642 if (acpi_has_method(dev->handle, "_STA")) 643 device_remove_file(&dev->dev, &dev_attr_status); 644 if (dev->handle) 645 device_remove_file(&dev->dev, &dev_attr_path); 646 } 647