1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Linux I2C core ACPI support code 4 * 5 * Copyright (C) 2014 Intel Corp, Author: Lan Tianyu <tianyu.lan@intel.com> 6 */ 7 8 #include <linux/acpi.h> 9 #include <linux/device.h> 10 #include <linux/err.h> 11 #include <linux/i2c.h> 12 #include <linux/list.h> 13 #include <linux/module.h> 14 #include <linux/slab.h> 15 16 #include "i2c-core.h" 17 18 struct i2c_acpi_handler_data { 19 struct acpi_connection_info info; 20 struct i2c_adapter *adapter; 21 }; 22 23 struct gsb_buffer { 24 u8 status; 25 u8 len; 26 union { 27 u16 wdata; 28 u8 bdata; 29 u8 data[0]; 30 }; 31 } __packed; 32 33 struct i2c_acpi_lookup { 34 struct i2c_board_info *info; 35 acpi_handle adapter_handle; 36 acpi_handle device_handle; 37 acpi_handle search_handle; 38 int n; 39 int index; 40 u32 speed; 41 u32 min_speed; 42 u32 force_speed; 43 }; 44 45 /** 46 * i2c_acpi_get_i2c_resource - Gets I2cSerialBus resource if type matches 47 * @ares: ACPI resource 48 * @i2c: Pointer to I2cSerialBus resource will be returned here 49 * 50 * Checks if the given ACPI resource is of type I2cSerialBus. 51 * In this case, returns a pointer to it to the caller. 52 * 53 * Returns true if resource type is of I2cSerialBus, otherwise false. 54 */ 55 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 56 struct acpi_resource_i2c_serialbus **i2c) 57 { 58 struct acpi_resource_i2c_serialbus *sb; 59 60 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) 61 return false; 62 63 sb = &ares->data.i2c_serial_bus; 64 if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) 65 return false; 66 67 *i2c = sb; 68 return true; 69 } 70 EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource); 71 72 static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data) 73 { 74 struct i2c_acpi_lookup *lookup = data; 75 struct i2c_board_info *info = lookup->info; 76 struct acpi_resource_i2c_serialbus *sb; 77 acpi_status status; 78 79 if (info->addr || !i2c_acpi_get_i2c_resource(ares, &sb)) 80 return 1; 81 82 if (lookup->index != -1 && lookup->n++ != lookup->index) 83 return 1; 84 85 status = acpi_get_handle(lookup->device_handle, 86 sb->resource_source.string_ptr, 87 &lookup->adapter_handle); 88 if (ACPI_FAILURE(status)) 89 return 1; 90 91 info->addr = sb->slave_address; 92 lookup->speed = sb->connection_speed; 93 if (sb->access_mode == ACPI_I2C_10BIT_MODE) 94 info->flags |= I2C_CLIENT_TEN; 95 96 return 1; 97 } 98 99 static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = { 100 /* 101 * ACPI video acpi_devices, which are handled by the acpi-video driver 102 * sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these. 103 */ 104 { ACPI_VIDEO_HID, 0 }, 105 {} 106 }; 107 108 static int i2c_acpi_do_lookup(struct acpi_device *adev, 109 struct i2c_acpi_lookup *lookup) 110 { 111 struct i2c_board_info *info = lookup->info; 112 struct list_head resource_list; 113 int ret; 114 115 if (acpi_bus_get_status(adev) || !adev->status.present) 116 return -EINVAL; 117 118 if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0) 119 return -ENODEV; 120 121 memset(info, 0, sizeof(*info)); 122 lookup->device_handle = acpi_device_handle(adev); 123 124 /* Look up for I2cSerialBus resource */ 125 INIT_LIST_HEAD(&resource_list); 126 ret = acpi_dev_get_resources(adev, &resource_list, 127 i2c_acpi_fill_info, lookup); 128 acpi_dev_free_resource_list(&resource_list); 129 130 if (ret < 0 || !info->addr) 131 return -EINVAL; 132 133 return 0; 134 } 135 136 static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data) 137 { 138 int *irq = data; 139 struct resource r; 140 141 if (*irq <= 0 && acpi_dev_resource_interrupt(ares, 0, &r)) 142 *irq = i2c_dev_irq_from_resources(&r, 1); 143 144 return 1; /* No need to add resource to the list */ 145 } 146 147 /** 148 * i2c_acpi_get_irq - get device IRQ number from ACPI 149 * @client: Pointer to the I2C client device 150 * 151 * Find the IRQ number used by a specific client device. 152 * 153 * Return: The IRQ number or an error code. 154 */ 155 int i2c_acpi_get_irq(struct i2c_client *client) 156 { 157 struct acpi_device *adev = ACPI_COMPANION(&client->dev); 158 struct list_head resource_list; 159 int irq = -ENOENT; 160 int ret; 161 162 INIT_LIST_HEAD(&resource_list); 163 164 ret = acpi_dev_get_resources(adev, &resource_list, 165 i2c_acpi_add_resource, &irq); 166 if (ret < 0) 167 return ret; 168 169 acpi_dev_free_resource_list(&resource_list); 170 171 if (irq == -ENOENT) 172 irq = acpi_dev_gpio_irq_get(adev, 0); 173 174 return irq; 175 } 176 177 static int i2c_acpi_get_info(struct acpi_device *adev, 178 struct i2c_board_info *info, 179 struct i2c_adapter *adapter, 180 acpi_handle *adapter_handle) 181 { 182 struct i2c_acpi_lookup lookup; 183 int ret; 184 185 memset(&lookup, 0, sizeof(lookup)); 186 lookup.info = info; 187 lookup.index = -1; 188 189 if (acpi_device_enumerated(adev)) 190 return -EINVAL; 191 192 ret = i2c_acpi_do_lookup(adev, &lookup); 193 if (ret) 194 return ret; 195 196 if (adapter) { 197 /* The adapter must match the one in I2cSerialBus() connector */ 198 if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle) 199 return -ENODEV; 200 } else { 201 struct acpi_device *adapter_adev; 202 203 /* The adapter must be present */ 204 if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev)) 205 return -ENODEV; 206 if (acpi_bus_get_status(adapter_adev) || 207 !adapter_adev->status.present) 208 return -ENODEV; 209 } 210 211 info->fwnode = acpi_fwnode_handle(adev); 212 if (adapter_handle) 213 *adapter_handle = lookup.adapter_handle; 214 215 acpi_set_modalias(adev, dev_name(&adev->dev), info->type, 216 sizeof(info->type)); 217 218 return 0; 219 } 220 221 static void i2c_acpi_register_device(struct i2c_adapter *adapter, 222 struct acpi_device *adev, 223 struct i2c_board_info *info) 224 { 225 adev->power.flags.ignore_parent = true; 226 acpi_device_set_enumerated(adev); 227 228 if (IS_ERR(i2c_new_client_device(adapter, info))) { 229 adev->power.flags.ignore_parent = false; 230 dev_err(&adapter->dev, 231 "failed to add I2C device %s from ACPI\n", 232 dev_name(&adev->dev)); 233 } 234 } 235 236 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level, 237 void *data, void **return_value) 238 { 239 struct i2c_adapter *adapter = data; 240 struct acpi_device *adev; 241 struct i2c_board_info info; 242 243 if (acpi_bus_get_device(handle, &adev)) 244 return AE_OK; 245 246 if (i2c_acpi_get_info(adev, &info, adapter, NULL)) 247 return AE_OK; 248 249 i2c_acpi_register_device(adapter, adev, &info); 250 251 return AE_OK; 252 } 253 254 #define I2C_ACPI_MAX_SCAN_DEPTH 32 255 256 /** 257 * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter 258 * @adap: pointer to adapter 259 * 260 * Enumerate all I2C slave devices behind this adapter by walking the ACPI 261 * namespace. When a device is found it will be added to the Linux device 262 * model and bound to the corresponding ACPI handle. 263 */ 264 void i2c_acpi_register_devices(struct i2c_adapter *adap) 265 { 266 acpi_status status; 267 268 if (!has_acpi_companion(&adap->dev)) 269 return; 270 271 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 272 I2C_ACPI_MAX_SCAN_DEPTH, 273 i2c_acpi_add_device, NULL, 274 adap, NULL); 275 if (ACPI_FAILURE(status)) 276 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n"); 277 } 278 279 const struct acpi_device_id * 280 i2c_acpi_match_device(const struct acpi_device_id *matches, 281 struct i2c_client *client) 282 { 283 if (!(client && matches)) 284 return NULL; 285 286 return acpi_match_device(matches, &client->dev); 287 } 288 289 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = { 290 /* 291 * These Silead touchscreen controllers only work at 400KHz, for 292 * some reason they do not work at 100KHz. On some devices the ACPI 293 * tables list another device at their bus as only being capable 294 * of 100KHz, testing has shown that these other devices work fine 295 * at 400KHz (as can be expected of any recent i2c hw) so we force 296 * the speed of the bus to 400 KHz if a Silead device is present. 297 */ 298 { "MSSL1680", 0 }, 299 {} 300 }; 301 302 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level, 303 void *data, void **return_value) 304 { 305 struct i2c_acpi_lookup *lookup = data; 306 struct acpi_device *adev; 307 308 if (acpi_bus_get_device(handle, &adev)) 309 return AE_OK; 310 311 if (i2c_acpi_do_lookup(adev, lookup)) 312 return AE_OK; 313 314 if (lookup->search_handle != lookup->adapter_handle) 315 return AE_OK; 316 317 if (lookup->speed <= lookup->min_speed) 318 lookup->min_speed = lookup->speed; 319 320 if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0) 321 lookup->force_speed = I2C_MAX_FAST_MODE_FREQ; 322 323 return AE_OK; 324 } 325 326 /** 327 * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI 328 * @dev: The device owning the bus 329 * 330 * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves 331 * devices connected to this bus and use the speed of slowest device. 332 * 333 * Returns the speed in Hz or zero 334 */ 335 u32 i2c_acpi_find_bus_speed(struct device *dev) 336 { 337 struct i2c_acpi_lookup lookup; 338 struct i2c_board_info dummy; 339 acpi_status status; 340 341 if (!has_acpi_companion(dev)) 342 return 0; 343 344 memset(&lookup, 0, sizeof(lookup)); 345 lookup.search_handle = ACPI_HANDLE(dev); 346 lookup.min_speed = UINT_MAX; 347 lookup.info = &dummy; 348 lookup.index = -1; 349 350 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 351 I2C_ACPI_MAX_SCAN_DEPTH, 352 i2c_acpi_lookup_speed, NULL, 353 &lookup, NULL); 354 355 if (ACPI_FAILURE(status)) { 356 dev_warn(dev, "unable to find I2C bus speed from ACPI\n"); 357 return 0; 358 } 359 360 if (lookup.force_speed) { 361 if (lookup.force_speed != lookup.min_speed) 362 dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n", 363 lookup.min_speed, lookup.force_speed); 364 return lookup.force_speed; 365 } else if (lookup.min_speed != UINT_MAX) { 366 return lookup.min_speed; 367 } else { 368 return 0; 369 } 370 } 371 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed); 372 373 static int i2c_acpi_find_match_adapter(struct device *dev, const void *data) 374 { 375 struct i2c_adapter *adapter = i2c_verify_adapter(dev); 376 377 if (!adapter) 378 return 0; 379 380 return ACPI_HANDLE(dev) == (acpi_handle)data; 381 } 382 383 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 384 { 385 struct device *dev; 386 387 dev = bus_find_device(&i2c_bus_type, NULL, handle, 388 i2c_acpi_find_match_adapter); 389 390 return dev ? i2c_verify_adapter(dev) : NULL; 391 } 392 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle); 393 394 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev) 395 { 396 struct device *dev; 397 struct i2c_client *client; 398 399 dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev); 400 if (!dev) 401 return NULL; 402 403 client = i2c_verify_client(dev); 404 if (!client) 405 put_device(dev); 406 407 return client; 408 } 409 410 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value, 411 void *arg) 412 { 413 struct acpi_device *adev = arg; 414 struct i2c_board_info info; 415 acpi_handle adapter_handle; 416 struct i2c_adapter *adapter; 417 struct i2c_client *client; 418 419 switch (value) { 420 case ACPI_RECONFIG_DEVICE_ADD: 421 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle)) 422 break; 423 424 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle); 425 if (!adapter) 426 break; 427 428 i2c_acpi_register_device(adapter, adev, &info); 429 break; 430 case ACPI_RECONFIG_DEVICE_REMOVE: 431 if (!acpi_device_enumerated(adev)) 432 break; 433 434 client = i2c_acpi_find_client_by_adev(adev); 435 if (!client) 436 break; 437 438 i2c_unregister_device(client); 439 put_device(&client->dev); 440 break; 441 } 442 443 return NOTIFY_OK; 444 } 445 446 struct notifier_block i2c_acpi_notifier = { 447 .notifier_call = i2c_acpi_notify, 448 }; 449 450 /** 451 * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource 452 * @dev: Device owning the ACPI resources to get the client from 453 * @index: Index of ACPI resource to get 454 * @info: describes the I2C device; note this is modified (addr gets set) 455 * Context: can sleep 456 * 457 * By default the i2c subsys creates an i2c-client for the first I2cSerialBus 458 * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus 459 * resources, in that case this function can be used to create an i2c-client 460 * for other I2cSerialBus resources in the Current Resource Settings table. 461 * 462 * Also see i2c_new_client_device, which this function calls to create the 463 * i2c-client. 464 * 465 * Returns a pointer to the new i2c-client, or error pointer in case of failure. 466 * Specifically, -EPROBE_DEFER is returned if the adapter is not found. 467 */ 468 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 469 struct i2c_board_info *info) 470 { 471 struct i2c_acpi_lookup lookup; 472 struct i2c_adapter *adapter; 473 struct acpi_device *adev; 474 LIST_HEAD(resource_list); 475 int ret; 476 477 adev = ACPI_COMPANION(dev); 478 if (!adev) 479 return ERR_PTR(-EINVAL); 480 481 memset(&lookup, 0, sizeof(lookup)); 482 lookup.info = info; 483 lookup.device_handle = acpi_device_handle(adev); 484 lookup.index = index; 485 486 ret = acpi_dev_get_resources(adev, &resource_list, 487 i2c_acpi_fill_info, &lookup); 488 if (ret < 0) 489 return ERR_PTR(ret); 490 491 acpi_dev_free_resource_list(&resource_list); 492 493 if (!info->addr) 494 return ERR_PTR(-EADDRNOTAVAIL); 495 496 adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle); 497 if (!adapter) 498 return ERR_PTR(-EPROBE_DEFER); 499 500 return i2c_new_client_device(adapter, info); 501 } 502 EXPORT_SYMBOL_GPL(i2c_acpi_new_device); 503 504 #ifdef CONFIG_ACPI_I2C_OPREGION 505 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client, 506 u8 cmd, u8 *data, u8 data_len) 507 { 508 509 struct i2c_msg msgs[2]; 510 int ret; 511 u8 *buffer; 512 513 buffer = kzalloc(data_len, GFP_KERNEL); 514 if (!buffer) 515 return AE_NO_MEMORY; 516 517 msgs[0].addr = client->addr; 518 msgs[0].flags = client->flags; 519 msgs[0].len = 1; 520 msgs[0].buf = &cmd; 521 522 msgs[1].addr = client->addr; 523 msgs[1].flags = client->flags | I2C_M_RD; 524 msgs[1].len = data_len; 525 msgs[1].buf = buffer; 526 527 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 528 if (ret < 0) { 529 /* Getting a NACK is unfortunately normal with some DSTDs */ 530 if (ret == -EREMOTEIO) 531 dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n", 532 data_len, client->addr, cmd, ret); 533 else 534 dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n", 535 data_len, client->addr, cmd, ret); 536 /* 2 transfers must have completed successfully */ 537 } else if (ret == 2) { 538 memcpy(data, buffer, data_len); 539 ret = 0; 540 } else { 541 ret = -EIO; 542 } 543 544 kfree(buffer); 545 return ret; 546 } 547 548 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client, 549 u8 cmd, u8 *data, u8 data_len) 550 { 551 552 struct i2c_msg msgs[1]; 553 u8 *buffer; 554 int ret = AE_OK; 555 556 buffer = kzalloc(data_len + 1, GFP_KERNEL); 557 if (!buffer) 558 return AE_NO_MEMORY; 559 560 buffer[0] = cmd; 561 memcpy(buffer + 1, data, data_len); 562 563 msgs[0].addr = client->addr; 564 msgs[0].flags = client->flags; 565 msgs[0].len = data_len + 1; 566 msgs[0].buf = buffer; 567 568 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 569 570 kfree(buffer); 571 572 if (ret < 0) { 573 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret); 574 return ret; 575 } 576 577 /* 1 transfer must have completed successfully */ 578 return (ret == 1) ? 0 : -EIO; 579 } 580 581 static acpi_status 582 i2c_acpi_space_handler(u32 function, acpi_physical_address command, 583 u32 bits, u64 *value64, 584 void *handler_context, void *region_context) 585 { 586 struct gsb_buffer *gsb = (struct gsb_buffer *)value64; 587 struct i2c_acpi_handler_data *data = handler_context; 588 struct acpi_connection_info *info = &data->info; 589 struct acpi_resource_i2c_serialbus *sb; 590 struct i2c_adapter *adapter = data->adapter; 591 struct i2c_client *client; 592 struct acpi_resource *ares; 593 u32 accessor_type = function >> 16; 594 u8 action = function & ACPI_IO_MASK; 595 acpi_status ret; 596 int status; 597 598 ret = acpi_buffer_to_resource(info->connection, info->length, &ares); 599 if (ACPI_FAILURE(ret)) 600 return ret; 601 602 client = kzalloc(sizeof(*client), GFP_KERNEL); 603 if (!client) { 604 ret = AE_NO_MEMORY; 605 goto err; 606 } 607 608 if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) { 609 ret = AE_BAD_PARAMETER; 610 goto err; 611 } 612 613 client->adapter = adapter; 614 client->addr = sb->slave_address; 615 616 if (sb->access_mode == ACPI_I2C_10BIT_MODE) 617 client->flags |= I2C_CLIENT_TEN; 618 619 switch (accessor_type) { 620 case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV: 621 if (action == ACPI_READ) { 622 status = i2c_smbus_read_byte(client); 623 if (status >= 0) { 624 gsb->bdata = status; 625 status = 0; 626 } 627 } else { 628 status = i2c_smbus_write_byte(client, gsb->bdata); 629 } 630 break; 631 632 case ACPI_GSB_ACCESS_ATTRIB_BYTE: 633 if (action == ACPI_READ) { 634 status = i2c_smbus_read_byte_data(client, command); 635 if (status >= 0) { 636 gsb->bdata = status; 637 status = 0; 638 } 639 } else { 640 status = i2c_smbus_write_byte_data(client, command, 641 gsb->bdata); 642 } 643 break; 644 645 case ACPI_GSB_ACCESS_ATTRIB_WORD: 646 if (action == ACPI_READ) { 647 status = i2c_smbus_read_word_data(client, command); 648 if (status >= 0) { 649 gsb->wdata = status; 650 status = 0; 651 } 652 } else { 653 status = i2c_smbus_write_word_data(client, command, 654 gsb->wdata); 655 } 656 break; 657 658 case ACPI_GSB_ACCESS_ATTRIB_BLOCK: 659 if (action == ACPI_READ) { 660 status = i2c_smbus_read_block_data(client, command, 661 gsb->data); 662 if (status >= 0) { 663 gsb->len = status; 664 status = 0; 665 } 666 } else { 667 status = i2c_smbus_write_block_data(client, command, 668 gsb->len, gsb->data); 669 } 670 break; 671 672 case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE: 673 if (action == ACPI_READ) { 674 status = acpi_gsb_i2c_read_bytes(client, command, 675 gsb->data, info->access_length); 676 } else { 677 status = acpi_gsb_i2c_write_bytes(client, command, 678 gsb->data, info->access_length); 679 } 680 break; 681 682 default: 683 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n", 684 accessor_type, client->addr); 685 ret = AE_BAD_PARAMETER; 686 goto err; 687 } 688 689 gsb->status = status; 690 691 err: 692 kfree(client); 693 ACPI_FREE(ares); 694 return ret; 695 } 696 697 698 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) 699 { 700 acpi_handle handle; 701 struct i2c_acpi_handler_data *data; 702 acpi_status status; 703 704 if (!adapter->dev.parent) 705 return -ENODEV; 706 707 handle = ACPI_HANDLE(adapter->dev.parent); 708 709 if (!handle) 710 return -ENODEV; 711 712 data = kzalloc(sizeof(struct i2c_acpi_handler_data), 713 GFP_KERNEL); 714 if (!data) 715 return -ENOMEM; 716 717 data->adapter = adapter; 718 status = acpi_bus_attach_private_data(handle, (void *)data); 719 if (ACPI_FAILURE(status)) { 720 kfree(data); 721 return -ENOMEM; 722 } 723 724 status = acpi_install_address_space_handler(handle, 725 ACPI_ADR_SPACE_GSBUS, 726 &i2c_acpi_space_handler, 727 NULL, 728 data); 729 if (ACPI_FAILURE(status)) { 730 dev_err(&adapter->dev, "Error installing i2c space handler\n"); 731 acpi_bus_detach_private_data(handle); 732 kfree(data); 733 return -ENOMEM; 734 } 735 736 acpi_walk_dep_device_list(handle); 737 return 0; 738 } 739 740 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) 741 { 742 acpi_handle handle; 743 struct i2c_acpi_handler_data *data; 744 acpi_status status; 745 746 if (!adapter->dev.parent) 747 return; 748 749 handle = ACPI_HANDLE(adapter->dev.parent); 750 751 if (!handle) 752 return; 753 754 acpi_remove_address_space_handler(handle, 755 ACPI_ADR_SPACE_GSBUS, 756 &i2c_acpi_space_handler); 757 758 status = acpi_bus_get_private_data(handle, (void **)&data); 759 if (ACPI_SUCCESS(status)) 760 kfree(data); 761 762 acpi_bus_detach_private_data(handle); 763 } 764 #endif /* CONFIG_ACPI_I2C_OPREGION */ 765