Mika Westerberg | ffdcd95 | 2014-10-21 13:33:55 +0200 | [diff] [blame] | 1 | /* |
| 2 | * ACPI device specific properties support. |
| 3 | * |
| 4 | * Copyright (C) 2014, Intel Corporation |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Authors: Mika Westerberg <mika.westerberg@linux.intel.com> |
| 8 | * Darren Hart <dvhart@linux.intel.com> |
| 9 | * Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
| 10 | * |
| 11 | * This program is free software; you can redistribute it and/or modify |
| 12 | * it under the terms of the GNU General Public License version 2 as |
| 13 | * published by the Free Software Foundation. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/acpi.h> |
| 17 | #include <linux/device.h> |
| 18 | #include <linux/export.h> |
| 19 | |
| 20 | #include "internal.h" |
| 21 | |
| 22 | /* ACPI _DSD device properties UUID: daffd814-6eba-4d8c-8a91-bc9bbf4aa301 */ |
| 23 | static const u8 prp_uuid[16] = { |
| 24 | 0x14, 0xd8, 0xff, 0xda, 0xba, 0x6e, 0x8c, 0x4d, |
| 25 | 0x8a, 0x91, 0xbc, 0x9b, 0xbf, 0x4a, 0xa3, 0x01 |
| 26 | }; |
| 27 | |
| 28 | static bool acpi_property_value_ok(const union acpi_object *value) |
| 29 | { |
| 30 | int j; |
| 31 | |
| 32 | /* |
| 33 | * The value must be an integer, a string, a reference, or a package |
| 34 | * whose every element must be an integer, a string, or a reference. |
| 35 | */ |
| 36 | switch (value->type) { |
| 37 | case ACPI_TYPE_INTEGER: |
| 38 | case ACPI_TYPE_STRING: |
| 39 | case ACPI_TYPE_LOCAL_REFERENCE: |
| 40 | return true; |
| 41 | |
| 42 | case ACPI_TYPE_PACKAGE: |
| 43 | for (j = 0; j < value->package.count; j++) |
| 44 | switch (value->package.elements[j].type) { |
| 45 | case ACPI_TYPE_INTEGER: |
| 46 | case ACPI_TYPE_STRING: |
| 47 | case ACPI_TYPE_LOCAL_REFERENCE: |
| 48 | continue; |
| 49 | |
| 50 | default: |
| 51 | return false; |
| 52 | } |
| 53 | |
| 54 | return true; |
| 55 | } |
| 56 | return false; |
| 57 | } |
| 58 | |
| 59 | static bool acpi_properties_format_valid(const union acpi_object *properties) |
| 60 | { |
| 61 | int i; |
| 62 | |
| 63 | for (i = 0; i < properties->package.count; i++) { |
| 64 | const union acpi_object *property; |
| 65 | |
| 66 | property = &properties->package.elements[i]; |
| 67 | /* |
| 68 | * Only two elements allowed, the first one must be a string and |
| 69 | * the second one has to satisfy certain conditions. |
| 70 | */ |
| 71 | if (property->package.count != 2 |
| 72 | || property->package.elements[0].type != ACPI_TYPE_STRING |
| 73 | || !acpi_property_value_ok(&property->package.elements[1])) |
| 74 | return false; |
| 75 | } |
| 76 | return true; |
| 77 | } |
| 78 | |
| 79 | void acpi_init_properties(struct acpi_device *adev) |
| 80 | { |
| 81 | struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; |
| 82 | const union acpi_object *desc; |
| 83 | acpi_status status; |
| 84 | int i; |
| 85 | |
| 86 | status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL, &buf, |
| 87 | ACPI_TYPE_PACKAGE); |
| 88 | if (ACPI_FAILURE(status)) |
| 89 | return; |
| 90 | |
| 91 | desc = buf.pointer; |
| 92 | if (desc->package.count % 2) |
| 93 | goto fail; |
| 94 | |
| 95 | /* Look for the device properties UUID. */ |
| 96 | for (i = 0; i < desc->package.count; i += 2) { |
| 97 | const union acpi_object *uuid, *properties; |
| 98 | |
| 99 | uuid = &desc->package.elements[i]; |
| 100 | properties = &desc->package.elements[i + 1]; |
| 101 | |
| 102 | /* |
| 103 | * The first element must be a UUID and the second one must be |
| 104 | * a package. |
| 105 | */ |
| 106 | if (uuid->type != ACPI_TYPE_BUFFER || uuid->buffer.length != 16 |
| 107 | || properties->type != ACPI_TYPE_PACKAGE) |
| 108 | break; |
| 109 | |
| 110 | if (memcmp(uuid->buffer.pointer, prp_uuid, sizeof(prp_uuid))) |
| 111 | continue; |
| 112 | |
| 113 | /* |
| 114 | * We found the matching UUID. Now validate the format of the |
| 115 | * package immediately following it. |
| 116 | */ |
| 117 | if (!acpi_properties_format_valid(properties)) |
| 118 | break; |
| 119 | |
| 120 | adev->data.pointer = buf.pointer; |
| 121 | adev->data.properties = properties; |
| 122 | return; |
| 123 | } |
| 124 | |
| 125 | fail: |
| 126 | dev_warn(&adev->dev, "Returned _DSD data is not valid, skipping\n"); |
| 127 | ACPI_FREE(buf.pointer); |
| 128 | } |
| 129 | |
| 130 | void acpi_free_properties(struct acpi_device *adev) |
| 131 | { |
| 132 | ACPI_FREE((void *)adev->data.pointer); |
| 133 | adev->data.pointer = NULL; |
| 134 | adev->data.properties = NULL; |
| 135 | } |
| 136 | |
| 137 | /** |
| 138 | * acpi_dev_get_property - return an ACPI property with given name |
| 139 | * @adev: ACPI device to get property |
| 140 | * @name: Name of the property |
| 141 | * @type: Expected property type |
| 142 | * @obj: Location to store the property value (if not %NULL) |
| 143 | * |
| 144 | * Look up a property with @name and store a pointer to the resulting ACPI |
| 145 | * object at the location pointed to by @obj if found. |
| 146 | * |
| 147 | * Callers must not attempt to free the returned objects. These objects will be |
| 148 | * freed by the ACPI core automatically during the removal of @adev. |
| 149 | * |
| 150 | * Return: %0 if property with @name has been found (success), |
| 151 | * %-EINVAL if the arguments are invalid, |
| 152 | * %-ENODATA if the property doesn't exist, |
| 153 | * %-EPROTO if the property value type doesn't match @type. |
| 154 | */ |
| 155 | int acpi_dev_get_property(struct acpi_device *adev, const char *name, |
| 156 | acpi_object_type type, const union acpi_object **obj) |
| 157 | { |
| 158 | const union acpi_object *properties; |
| 159 | int i; |
| 160 | |
| 161 | if (!adev || !name) |
| 162 | return -EINVAL; |
| 163 | |
| 164 | if (!adev->data.pointer || !adev->data.properties) |
| 165 | return -ENODATA; |
| 166 | |
| 167 | properties = adev->data.properties; |
| 168 | for (i = 0; i < properties->package.count; i++) { |
| 169 | const union acpi_object *propname, *propvalue; |
| 170 | const union acpi_object *property; |
| 171 | |
| 172 | property = &properties->package.elements[i]; |
| 173 | |
| 174 | propname = &property->package.elements[0]; |
| 175 | propvalue = &property->package.elements[1]; |
| 176 | |
| 177 | if (!strcmp(name, propname->string.pointer)) { |
| 178 | if (type != ACPI_TYPE_ANY && propvalue->type != type) |
| 179 | return -EPROTO; |
| 180 | else if (obj) |
| 181 | *obj = propvalue; |
| 182 | |
| 183 | return 0; |
| 184 | } |
| 185 | } |
| 186 | return -ENODATA; |
| 187 | } |
| 188 | EXPORT_SYMBOL_GPL(acpi_dev_get_property); |
| 189 | |
| 190 | /** |
| 191 | * acpi_dev_get_property_array - return an ACPI array property with given name |
| 192 | * @adev: ACPI device to get property |
| 193 | * @name: Name of the property |
| 194 | * @type: Expected type of array elements |
| 195 | * @obj: Location to store a pointer to the property value (if not NULL) |
| 196 | * |
| 197 | * Look up an array property with @name and store a pointer to the resulting |
| 198 | * ACPI object at the location pointed to by @obj if found. |
| 199 | * |
| 200 | * Callers must not attempt to free the returned objects. Those objects will be |
| 201 | * freed by the ACPI core automatically during the removal of @adev. |
| 202 | * |
| 203 | * Return: %0 if array property (package) with @name has been found (success), |
| 204 | * %-EINVAL if the arguments are invalid, |
| 205 | * %-ENODATA if the property doesn't exist, |
| 206 | * %-EPROTO if the property is not a package or the type of its elements |
| 207 | * doesn't match @type. |
| 208 | */ |
| 209 | int acpi_dev_get_property_array(struct acpi_device *adev, const char *name, |
| 210 | acpi_object_type type, |
| 211 | const union acpi_object **obj) |
| 212 | { |
| 213 | const union acpi_object *prop; |
| 214 | int ret, i; |
| 215 | |
| 216 | ret = acpi_dev_get_property(adev, name, ACPI_TYPE_PACKAGE, &prop); |
| 217 | if (ret) |
| 218 | return ret; |
| 219 | |
| 220 | if (type != ACPI_TYPE_ANY) { |
| 221 | /* Check that all elements are of correct type. */ |
| 222 | for (i = 0; i < prop->package.count; i++) |
| 223 | if (prop->package.elements[i].type != type) |
| 224 | return -EPROTO; |
| 225 | } |
| 226 | if (obj) |
| 227 | *obj = prop; |
| 228 | |
| 229 | return 0; |
| 230 | } |
| 231 | EXPORT_SYMBOL_GPL(acpi_dev_get_property_array); |
| 232 | |
| 233 | /** |
| 234 | * acpi_dev_get_property_reference - returns handle to the referenced object |
| 235 | * @adev: ACPI device to get property |
| 236 | * @name: Name of the property |
| 237 | * @size_prop: Name of the "size" property in referenced object |
| 238 | * @index: Index of the reference to return |
| 239 | * @args: Location to store the returned reference with optional arguments |
| 240 | * |
| 241 | * Find property with @name, verifify that it is a package containing at least |
| 242 | * one object reference and if so, store the ACPI device object pointer to the |
| 243 | * target object in @args->adev. |
| 244 | * |
| 245 | * If the reference includes arguments (@size_prop is not %NULL) follow the |
| 246 | * reference and check whether or not there is an integer property @size_prop |
| 247 | * under the target object and if so, whether or not its value matches the |
| 248 | * number of arguments that follow the reference. If there's more than one |
| 249 | * reference in the property value package, @index is used to select the one to |
| 250 | * return. |
| 251 | * |
| 252 | * Return: %0 on success, negative error code on failure. |
| 253 | */ |
| 254 | int acpi_dev_get_property_reference(struct acpi_device *adev, const char *name, |
| 255 | const char *size_prop, size_t index, |
| 256 | struct acpi_reference_args *args) |
| 257 | { |
| 258 | const union acpi_object *element, *end; |
| 259 | const union acpi_object *obj; |
| 260 | struct acpi_device *device; |
| 261 | int ret, idx = 0; |
| 262 | |
| 263 | ret = acpi_dev_get_property(adev, name, ACPI_TYPE_ANY, &obj); |
| 264 | if (ret) |
| 265 | return ret; |
| 266 | |
| 267 | /* |
| 268 | * The simplest case is when the value is a single reference. Just |
| 269 | * return that reference then. |
| 270 | */ |
| 271 | if (obj->type == ACPI_TYPE_LOCAL_REFERENCE) { |
| 272 | if (size_prop || index) |
| 273 | return -EINVAL; |
| 274 | |
| 275 | ret = acpi_bus_get_device(obj->reference.handle, &device); |
| 276 | if (ret) |
| 277 | return ret; |
| 278 | |
| 279 | args->adev = device; |
| 280 | args->nargs = 0; |
| 281 | return 0; |
| 282 | } |
| 283 | |
| 284 | /* |
| 285 | * If it is not a single reference, then it is a package of |
| 286 | * references followed by number of ints as follows: |
| 287 | * |
| 288 | * Package () { REF, INT, REF, INT, INT } |
| 289 | * |
| 290 | * The index argument is then used to determine which reference |
| 291 | * the caller wants (along with the arguments). |
| 292 | */ |
| 293 | if (obj->type != ACPI_TYPE_PACKAGE || index >= obj->package.count) |
| 294 | return -EPROTO; |
| 295 | |
| 296 | element = obj->package.elements; |
| 297 | end = element + obj->package.count; |
| 298 | |
| 299 | while (element < end) { |
| 300 | u32 nargs, i; |
| 301 | |
| 302 | if (element->type != ACPI_TYPE_LOCAL_REFERENCE) |
| 303 | return -EPROTO; |
| 304 | |
| 305 | ret = acpi_bus_get_device(element->reference.handle, &device); |
| 306 | if (ret) |
| 307 | return -ENODEV; |
| 308 | |
| 309 | element++; |
| 310 | nargs = 0; |
| 311 | |
| 312 | if (size_prop) { |
| 313 | const union acpi_object *prop; |
| 314 | |
| 315 | /* |
| 316 | * Find out how many arguments the refenced object |
| 317 | * expects by reading its size_prop property. |
| 318 | */ |
| 319 | ret = acpi_dev_get_property(device, size_prop, |
| 320 | ACPI_TYPE_INTEGER, &prop); |
| 321 | if (ret) |
| 322 | return ret; |
| 323 | |
| 324 | nargs = prop->integer.value; |
| 325 | if (nargs > MAX_ACPI_REFERENCE_ARGS |
| 326 | || element + nargs > end) |
| 327 | return -EPROTO; |
| 328 | |
| 329 | /* |
| 330 | * Skip to the start of the arguments and verify |
| 331 | * that they all are in fact integers. |
| 332 | */ |
| 333 | for (i = 0; i < nargs; i++) |
| 334 | if (element[i].type != ACPI_TYPE_INTEGER) |
| 335 | return -EPROTO; |
| 336 | } else { |
| 337 | /* assume following integer elements are all args */ |
| 338 | for (i = 0; element + i < end; i++) { |
| 339 | int type = element[i].type; |
| 340 | |
| 341 | if (type == ACPI_TYPE_INTEGER) |
| 342 | nargs++; |
| 343 | else if (type == ACPI_TYPE_LOCAL_REFERENCE) |
| 344 | break; |
| 345 | else |
| 346 | return -EPROTO; |
| 347 | } |
| 348 | } |
| 349 | |
| 350 | if (idx++ == index) { |
| 351 | args->adev = device; |
| 352 | args->nargs = nargs; |
| 353 | for (i = 0; i < nargs; i++) |
| 354 | args->args[i] = element[i].integer.value; |
| 355 | |
| 356 | return 0; |
| 357 | } |
| 358 | |
| 359 | element += nargs; |
| 360 | } |
| 361 | |
| 362 | return -EPROTO; |
| 363 | } |
| 364 | EXPORT_SYMBOL_GPL(acpi_dev_get_property_reference); |
Rafael J. Wysocki | b31384f | 2014-11-04 01:28:56 +0100 | [diff] [blame^] | 365 | |
| 366 | int acpi_dev_prop_get(struct acpi_device *adev, const char *propname, |
| 367 | void **valptr) |
| 368 | { |
| 369 | return acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY, |
| 370 | (const union acpi_object **)valptr); |
| 371 | } |
| 372 | |
| 373 | int acpi_dev_prop_read_single(struct acpi_device *adev, const char *propname, |
| 374 | enum dev_prop_type proptype, void *val) |
| 375 | { |
| 376 | const union acpi_object *obj; |
| 377 | int ret; |
| 378 | |
| 379 | if (!val) |
| 380 | return -EINVAL; |
| 381 | |
| 382 | if (proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64) { |
| 383 | ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_INTEGER, &obj); |
| 384 | if (ret) |
| 385 | return ret; |
| 386 | |
| 387 | switch (proptype) { |
| 388 | case DEV_PROP_U8: |
| 389 | if (obj->integer.value > U8_MAX) |
| 390 | return -EOVERFLOW; |
| 391 | *(u8 *)val = obj->integer.value; |
| 392 | break; |
| 393 | case DEV_PROP_U16: |
| 394 | if (obj->integer.value > U16_MAX) |
| 395 | return -EOVERFLOW; |
| 396 | *(u16 *)val = obj->integer.value; |
| 397 | break; |
| 398 | case DEV_PROP_U32: |
| 399 | if (obj->integer.value > U32_MAX) |
| 400 | return -EOVERFLOW; |
| 401 | *(u32 *)val = obj->integer.value; |
| 402 | break; |
| 403 | default: |
| 404 | *(u64 *)val = obj->integer.value; |
| 405 | break; |
| 406 | } |
| 407 | } else if (proptype == DEV_PROP_STRING) { |
| 408 | ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_STRING, &obj); |
| 409 | if (ret) |
| 410 | return ret; |
| 411 | |
| 412 | *(char **)val = obj->string.pointer; |
| 413 | } else { |
| 414 | ret = -EINVAL; |
| 415 | } |
| 416 | return ret; |
| 417 | } |
| 418 | |
| 419 | static int acpi_copy_property_array_u8(const union acpi_object *items, u8 *val, |
| 420 | size_t nval) |
| 421 | { |
| 422 | int i; |
| 423 | |
| 424 | for (i = 0; i < nval; i++) { |
| 425 | if (items[i].type != ACPI_TYPE_INTEGER) |
| 426 | return -EPROTO; |
| 427 | if (items[i].integer.value > U8_MAX) |
| 428 | return -EOVERFLOW; |
| 429 | |
| 430 | val[i] = items[i].integer.value; |
| 431 | } |
| 432 | return 0; |
| 433 | } |
| 434 | |
| 435 | static int acpi_copy_property_array_u16(const union acpi_object *items, |
| 436 | u16 *val, size_t nval) |
| 437 | { |
| 438 | int i; |
| 439 | |
| 440 | for (i = 0; i < nval; i++) { |
| 441 | if (items[i].type != ACPI_TYPE_INTEGER) |
| 442 | return -EPROTO; |
| 443 | if (items[i].integer.value > U16_MAX) |
| 444 | return -EOVERFLOW; |
| 445 | |
| 446 | val[i] = items[i].integer.value; |
| 447 | } |
| 448 | return 0; |
| 449 | } |
| 450 | |
| 451 | static int acpi_copy_property_array_u32(const union acpi_object *items, |
| 452 | u32 *val, size_t nval) |
| 453 | { |
| 454 | int i; |
| 455 | |
| 456 | for (i = 0; i < nval; i++) { |
| 457 | if (items[i].type != ACPI_TYPE_INTEGER) |
| 458 | return -EPROTO; |
| 459 | if (items[i].integer.value > U32_MAX) |
| 460 | return -EOVERFLOW; |
| 461 | |
| 462 | val[i] = items[i].integer.value; |
| 463 | } |
| 464 | return 0; |
| 465 | } |
| 466 | |
| 467 | static int acpi_copy_property_array_u64(const union acpi_object *items, |
| 468 | u64 *val, size_t nval) |
| 469 | { |
| 470 | int i; |
| 471 | |
| 472 | for (i = 0; i < nval; i++) { |
| 473 | if (items[i].type != ACPI_TYPE_INTEGER) |
| 474 | return -EPROTO; |
| 475 | |
| 476 | val[i] = items[i].integer.value; |
| 477 | } |
| 478 | return 0; |
| 479 | } |
| 480 | |
| 481 | static int acpi_copy_property_array_string(const union acpi_object *items, |
| 482 | char **val, size_t nval) |
| 483 | { |
| 484 | int i; |
| 485 | |
| 486 | for (i = 0; i < nval; i++) { |
| 487 | if (items[i].type != ACPI_TYPE_STRING) |
| 488 | return -EPROTO; |
| 489 | |
| 490 | val[i] = items[i].string.pointer; |
| 491 | } |
| 492 | return 0; |
| 493 | } |
| 494 | |
| 495 | int acpi_dev_prop_read(struct acpi_device *adev, const char *propname, |
| 496 | enum dev_prop_type proptype, void *val, size_t nval) |
| 497 | { |
| 498 | const union acpi_object *obj; |
| 499 | const union acpi_object *items; |
| 500 | int ret; |
| 501 | |
| 502 | if (val && nval == 1) { |
| 503 | ret = acpi_dev_prop_read_single(adev, propname, proptype, val); |
| 504 | if (!ret) |
| 505 | return ret; |
| 506 | } |
| 507 | |
| 508 | ret = acpi_dev_get_property_array(adev, propname, ACPI_TYPE_ANY, &obj); |
| 509 | if (ret) |
| 510 | return ret; |
| 511 | |
| 512 | if (!val) |
| 513 | return obj->package.count; |
| 514 | else if (nval <= 0) |
| 515 | return -EINVAL; |
| 516 | |
| 517 | if (nval > obj->package.count) |
| 518 | return -EOVERFLOW; |
| 519 | |
| 520 | items = obj->package.elements; |
| 521 | switch (proptype) { |
| 522 | case DEV_PROP_U8: |
| 523 | ret = acpi_copy_property_array_u8(items, (u8 *)val, nval); |
| 524 | break; |
| 525 | case DEV_PROP_U16: |
| 526 | ret = acpi_copy_property_array_u16(items, (u16 *)val, nval); |
| 527 | break; |
| 528 | case DEV_PROP_U32: |
| 529 | ret = acpi_copy_property_array_u32(items, (u32 *)val, nval); |
| 530 | break; |
| 531 | case DEV_PROP_U64: |
| 532 | ret = acpi_copy_property_array_u64(items, (u64 *)val, nval); |
| 533 | break; |
| 534 | case DEV_PROP_STRING: |
| 535 | ret = acpi_copy_property_array_string(items, (char **)val, nval); |
| 536 | break; |
| 537 | default: |
| 538 | ret = -EINVAL; |
| 539 | break; |
| 540 | } |
| 541 | return ret; |
| 542 | } |