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 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(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 <= 0) 162 return len; 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 if (count < 0) 172 return -EINVAL; 173 174 if (count >= size) 175 return -ENOMEM; 176 177 len += count; 178 size -= count; 179 } 180 modalias[len] = '\0'; 181 return len; 182 } 183 184 /** 185 * create_of_modalias - Creates DT compatible string for modalias and uevent 186 * @acpi_dev: ACPI device object. 187 * @modalias: Buffer to print into. 188 * @size: Size of the buffer. 189 * 190 * Expose DT compatible modalias as of:NnameTCcompatible. This function should 191 * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of 192 * ACPI/PNP IDs. 193 */ 194 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias, 195 int size) 196 { 197 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 198 const union acpi_object *of_compatible, *obj; 199 acpi_status status; 200 int len, count; 201 int i, nval; 202 char *c; 203 204 status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf); 205 if (ACPI_FAILURE(status)) 206 return -ENODEV; 207 208 /* DT strings are all in lower case */ 209 for (c = buf.pointer; *c != '\0'; c++) 210 *c = tolower(*c); 211 212 len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer); 213 ACPI_FREE(buf.pointer); 214 215 if (len <= 0) 216 return 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 if (count < 0) 230 return -EINVAL; 231 232 if (count >= size) 233 return -ENOMEM; 234 235 len += count; 236 size -= count; 237 } 238 modalias[len] = '\0'; 239 return len; 240 } 241 242 int __acpi_device_uevent_modalias(struct acpi_device *adev, 243 struct kobj_uevent_env *env) 244 { 245 int len; 246 247 if (!adev) 248 return -ENODEV; 249 250 if (list_empty(&adev->pnp.ids)) 251 return 0; 252 253 if (add_uevent_var(env, "MODALIAS=")) 254 return -ENOMEM; 255 256 if (adev->data.of_compatible) 257 len = create_of_modalias(adev, &env->buf[env->buflen - 1], 258 sizeof(env->buf) - env->buflen); 259 else 260 len = create_pnp_modalias(adev, &env->buf[env->buflen - 1], 261 sizeof(env->buf) - env->buflen); 262 if (len < 0) 263 return len; 264 265 env->buflen += len; 266 267 return 0; 268 } 269 270 /** 271 * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices. 272 * @dev: Struct device to get ACPI device node. 273 * @env: Environment variables of the kobject uevent. 274 * 275 * Create the uevent modalias field for ACPI-enumerated devices. 276 * 277 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with 278 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001". 279 */ 280 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 281 { 282 return __acpi_device_uevent_modalias(acpi_companion_match(dev), env); 283 } 284 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias); 285 286 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size) 287 { 288 int len, count; 289 290 if (!adev) 291 return -ENODEV; 292 293 if (list_empty(&adev->pnp.ids)) 294 return 0; 295 296 len = create_pnp_modalias(adev, buf, size - 1); 297 if (len < 0) { 298 return len; 299 } else if (len > 0) { 300 buf[len++] = '\n'; 301 size -= len; 302 } 303 if (!adev->data.of_compatible) 304 return len; 305 306 count = create_of_modalias(adev, buf + len, size - 1); 307 if (count < 0) { 308 return count; 309 } else if (count > 0) { 310 len += count; 311 buf[len++] = '\n'; 312 } 313 314 return len; 315 } 316 317 /** 318 * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices. 319 * @dev: Struct device to get ACPI device node. 320 * @buf: The buffer to save pnp_modalias and of_modalias. 321 * @size: Size of buffer. 322 * 323 * Create the modalias sysfs attribute for ACPI-enumerated devices. 324 * 325 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with 326 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001". 327 */ 328 int acpi_device_modalias(struct device *dev, char *buf, int size) 329 { 330 return __acpi_device_modalias(acpi_companion_match(dev), buf, size); 331 } 332 EXPORT_SYMBOL_GPL(acpi_device_modalias); 333 334 static ssize_t 335 modalias_show(struct device *dev, struct device_attribute *attr, char *buf) 336 { 337 return __acpi_device_modalias(to_acpi_device(dev), buf, 1024); 338 } 339 static DEVICE_ATTR_RO(modalias); 340 341 static ssize_t real_power_state_show(struct device *dev, 342 struct device_attribute *attr, char *buf) 343 { 344 struct acpi_device *adev = to_acpi_device(dev); 345 int state; 346 int ret; 347 348 ret = acpi_device_get_power(adev, &state); 349 if (ret) 350 return ret; 351 352 return sprintf(buf, "%s\n", acpi_power_state_string(state)); 353 } 354 355 static DEVICE_ATTR_RO(real_power_state); 356 357 static ssize_t power_state_show(struct device *dev, 358 struct device_attribute *attr, char *buf) 359 { 360 struct acpi_device *adev = to_acpi_device(dev); 361 362 return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state)); 363 } 364 365 static DEVICE_ATTR_RO(power_state); 366 367 static ssize_t 368 eject_store(struct device *d, struct device_attribute *attr, 369 const char *buf, size_t count) 370 { 371 struct acpi_device *acpi_device = to_acpi_device(d); 372 acpi_object_type not_used; 373 acpi_status status; 374 375 if (!count || buf[0] != '1') 376 return -EINVAL; 377 378 if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled) 379 && !d->driver) 380 return -ENODEV; 381 382 status = acpi_get_type(acpi_device->handle, ¬_used); 383 if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable) 384 return -ENODEV; 385 386 acpi_dev_get(acpi_device); 387 status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT); 388 if (ACPI_SUCCESS(status)) 389 return count; 390 391 acpi_dev_put(acpi_device); 392 acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT, 393 ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL); 394 return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN; 395 } 396 397 static DEVICE_ATTR_WO(eject); 398 399 static ssize_t 400 hid_show(struct device *dev, struct device_attribute *attr, char *buf) 401 { 402 struct acpi_device *acpi_dev = to_acpi_device(dev); 403 404 return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev)); 405 } 406 static DEVICE_ATTR_RO(hid); 407 408 static ssize_t uid_show(struct device *dev, 409 struct device_attribute *attr, char *buf) 410 { 411 struct acpi_device *acpi_dev = to_acpi_device(dev); 412 413 return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id); 414 } 415 static DEVICE_ATTR_RO(uid); 416 417 static ssize_t adr_show(struct device *dev, 418 struct device_attribute *attr, char *buf) 419 { 420 struct acpi_device *acpi_dev = to_acpi_device(dev); 421 422 if (acpi_dev->pnp.bus_address > U32_MAX) 423 return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address); 424 else 425 return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address); 426 } 427 static DEVICE_ATTR_RO(adr); 428 429 static ssize_t path_show(struct device *dev, 430 struct device_attribute *attr, char *buf) 431 { 432 struct acpi_device *acpi_dev = to_acpi_device(dev); 433 434 return acpi_object_path(acpi_dev->handle, buf); 435 } 436 static DEVICE_ATTR_RO(path); 437 438 /* sysfs file that shows description text from the ACPI _STR method */ 439 static ssize_t description_show(struct device *dev, 440 struct device_attribute *attr, 441 char *buf) 442 { 443 struct acpi_device *acpi_dev = to_acpi_device(dev); 444 int result; 445 446 if (acpi_dev->pnp.str_obj == NULL) 447 return 0; 448 449 /* 450 * The _STR object contains a Unicode identifier for a device. 451 * We need to convert to utf-8 so it can be displayed. 452 */ 453 result = utf16s_to_utf8s( 454 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer, 455 acpi_dev->pnp.str_obj->buffer.length, 456 UTF16_LITTLE_ENDIAN, buf, 457 PAGE_SIZE - 1); 458 459 buf[result++] = '\n'; 460 461 return result; 462 } 463 static DEVICE_ATTR_RO(description); 464 465 static ssize_t 466 sun_show(struct device *dev, struct device_attribute *attr, 467 char *buf) 468 { 469 struct acpi_device *acpi_dev = to_acpi_device(dev); 470 acpi_status status; 471 unsigned long long sun; 472 473 status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun); 474 if (ACPI_FAILURE(status)) 475 return -EIO; 476 477 return sprintf(buf, "%llu\n", sun); 478 } 479 static DEVICE_ATTR_RO(sun); 480 481 static ssize_t 482 hrv_show(struct device *dev, struct device_attribute *attr, 483 char *buf) 484 { 485 struct acpi_device *acpi_dev = to_acpi_device(dev); 486 acpi_status status; 487 unsigned long long hrv; 488 489 status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv); 490 if (ACPI_FAILURE(status)) 491 return -EIO; 492 493 return sprintf(buf, "%llu\n", hrv); 494 } 495 static DEVICE_ATTR_RO(hrv); 496 497 static ssize_t status_show(struct device *dev, struct device_attribute *attr, 498 char *buf) 499 { 500 struct acpi_device *acpi_dev = to_acpi_device(dev); 501 acpi_status status; 502 unsigned long long sta; 503 504 status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta); 505 if (ACPI_FAILURE(status)) 506 return -EIO; 507 508 return sprintf(buf, "%llu\n", sta); 509 } 510 static DEVICE_ATTR_RO(status); 511 512 /** 513 * acpi_device_setup_files - Create sysfs attributes of an ACPI device. 514 * @dev: ACPI device object. 515 */ 516 int acpi_device_setup_files(struct acpi_device *dev) 517 { 518 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; 519 acpi_status status; 520 int result = 0; 521 522 /* 523 * Devices gotten from FADT don't have a "path" attribute 524 */ 525 if (dev->handle) { 526 result = device_create_file(&dev->dev, &dev_attr_path); 527 if (result) 528 goto end; 529 } 530 531 if (!list_empty(&dev->pnp.ids)) { 532 result = device_create_file(&dev->dev, &dev_attr_hid); 533 if (result) 534 goto end; 535 536 result = device_create_file(&dev->dev, &dev_attr_modalias); 537 if (result) 538 goto end; 539 } 540 541 /* 542 * If device has _STR, 'description' file is created 543 */ 544 if (acpi_has_method(dev->handle, "_STR")) { 545 status = acpi_evaluate_object(dev->handle, "_STR", 546 NULL, &buffer); 547 if (ACPI_FAILURE(status)) 548 buffer.pointer = NULL; 549 dev->pnp.str_obj = buffer.pointer; 550 result = device_create_file(&dev->dev, &dev_attr_description); 551 if (result) 552 goto end; 553 } 554 555 if (dev->pnp.type.bus_address) 556 result = device_create_file(&dev->dev, &dev_attr_adr); 557 if (dev->pnp.unique_id) 558 result = device_create_file(&dev->dev, &dev_attr_uid); 559 560 if (acpi_has_method(dev->handle, "_SUN")) { 561 result = device_create_file(&dev->dev, &dev_attr_sun); 562 if (result) 563 goto end; 564 } 565 566 if (acpi_has_method(dev->handle, "_HRV")) { 567 result = device_create_file(&dev->dev, &dev_attr_hrv); 568 if (result) 569 goto end; 570 } 571 572 if (acpi_has_method(dev->handle, "_STA")) { 573 result = device_create_file(&dev->dev, &dev_attr_status); 574 if (result) 575 goto end; 576 } 577 578 /* 579 * If device has _EJ0, 'eject' file is created that is used to trigger 580 * hot-removal function from userland. 581 */ 582 if (acpi_has_method(dev->handle, "_EJ0")) { 583 result = device_create_file(&dev->dev, &dev_attr_eject); 584 if (result) 585 return result; 586 } 587 588 if (dev->flags.power_manageable) { 589 result = device_create_file(&dev->dev, &dev_attr_power_state); 590 if (result) 591 return result; 592 593 if (dev->power.flags.power_resources) 594 result = device_create_file(&dev->dev, 595 &dev_attr_real_power_state); 596 } 597 598 acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data); 599 600 end: 601 return result; 602 } 603 604 /** 605 * acpi_device_remove_files - Remove sysfs attributes of an ACPI device. 606 * @dev: ACPI device object. 607 */ 608 void acpi_device_remove_files(struct acpi_device *dev) 609 { 610 acpi_hide_nondev_subnodes(&dev->data); 611 612 if (dev->flags.power_manageable) { 613 device_remove_file(&dev->dev, &dev_attr_power_state); 614 if (dev->power.flags.power_resources) 615 device_remove_file(&dev->dev, 616 &dev_attr_real_power_state); 617 } 618 619 /* 620 * If device has _STR, remove 'description' file 621 */ 622 if (acpi_has_method(dev->handle, "_STR")) { 623 kfree(dev->pnp.str_obj); 624 device_remove_file(&dev->dev, &dev_attr_description); 625 } 626 /* 627 * If device has _EJ0, remove 'eject' file. 628 */ 629 if (acpi_has_method(dev->handle, "_EJ0")) 630 device_remove_file(&dev->dev, &dev_attr_eject); 631 632 if (acpi_has_method(dev->handle, "_SUN")) 633 device_remove_file(&dev->dev, &dev_attr_sun); 634 635 if (acpi_has_method(dev->handle, "_HRV")) 636 device_remove_file(&dev->dev, &dev_attr_hrv); 637 638 if (dev->pnp.unique_id) 639 device_remove_file(&dev->dev, &dev_attr_uid); 640 if (dev->pnp.type.bus_address) 641 device_remove_file(&dev->dev, &dev_attr_adr); 642 device_remove_file(&dev->dev, &dev_attr_modalias); 643 device_remove_file(&dev->dev, &dev_attr_hid); 644 if (acpi_has_method(dev->handle, "_STA")) 645 device_remove_file(&dev->dev, &dev_attr_status); 646 if (dev->handle) 647 device_remove_file(&dev->dev, &dev_attr_path); 648 } 649