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