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 } 231 232 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level, 233 void *data, void **return_value) 234 { 235 struct i2c_adapter *adapter = data; 236 struct acpi_device *adev; 237 struct i2c_board_info info; 238 239 if (acpi_bus_get_device(handle, &adev)) 240 return AE_OK; 241 242 if (i2c_acpi_get_info(adev, &info, adapter, NULL)) 243 return AE_OK; 244 245 i2c_acpi_register_device(adapter, adev, &info); 246 247 return AE_OK; 248 } 249 250 #define I2C_ACPI_MAX_SCAN_DEPTH 32 251 252 /** 253 * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter 254 * @adap: pointer to adapter 255 * 256 * Enumerate all I2C slave devices behind this adapter by walking the ACPI 257 * namespace. When a device is found it will be added to the Linux device 258 * model and bound to the corresponding ACPI handle. 259 */ 260 void i2c_acpi_register_devices(struct i2c_adapter *adap) 261 { 262 struct acpi_device *adev; 263 acpi_status status; 264 265 if (!has_acpi_companion(&adap->dev)) 266 return; 267 268 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 269 I2C_ACPI_MAX_SCAN_DEPTH, 270 i2c_acpi_add_device, NULL, 271 adap, NULL); 272 if (ACPI_FAILURE(status)) 273 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n"); 274 275 if (!adap->dev.parent) 276 return; 277 278 adev = ACPI_COMPANION(adap->dev.parent); 279 if (!adev) 280 return; 281 282 acpi_dev_clear_dependencies(adev); 283 } 284 285 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = { 286 /* 287 * These Silead touchscreen controllers only work at 400KHz, for 288 * some reason they do not work at 100KHz. On some devices the ACPI 289 * tables list another device at their bus as only being capable 290 * of 100KHz, testing has shown that these other devices work fine 291 * at 400KHz (as can be expected of any recent i2c hw) so we force 292 * the speed of the bus to 400 KHz if a Silead device is present. 293 */ 294 { "MSSL1680", 0 }, 295 {} 296 }; 297 298 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level, 299 void *data, void **return_value) 300 { 301 struct i2c_acpi_lookup *lookup = data; 302 struct acpi_device *adev; 303 304 if (acpi_bus_get_device(handle, &adev)) 305 return AE_OK; 306 307 if (i2c_acpi_do_lookup(adev, lookup)) 308 return AE_OK; 309 310 if (lookup->search_handle != lookup->adapter_handle) 311 return AE_OK; 312 313 if (lookup->speed <= lookup->min_speed) 314 lookup->min_speed = lookup->speed; 315 316 if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0) 317 lookup->force_speed = I2C_MAX_FAST_MODE_FREQ; 318 319 return AE_OK; 320 } 321 322 /** 323 * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI 324 * @dev: The device owning the bus 325 * 326 * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves 327 * devices connected to this bus and use the speed of slowest device. 328 * 329 * Returns the speed in Hz or zero 330 */ 331 u32 i2c_acpi_find_bus_speed(struct device *dev) 332 { 333 struct i2c_acpi_lookup lookup; 334 struct i2c_board_info dummy; 335 acpi_status status; 336 337 if (!has_acpi_companion(dev)) 338 return 0; 339 340 memset(&lookup, 0, sizeof(lookup)); 341 lookup.search_handle = ACPI_HANDLE(dev); 342 lookup.min_speed = UINT_MAX; 343 lookup.info = &dummy; 344 lookup.index = -1; 345 346 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 347 I2C_ACPI_MAX_SCAN_DEPTH, 348 i2c_acpi_lookup_speed, NULL, 349 &lookup, NULL); 350 351 if (ACPI_FAILURE(status)) { 352 dev_warn(dev, "unable to find I2C bus speed from ACPI\n"); 353 return 0; 354 } 355 356 if (lookup.force_speed) { 357 if (lookup.force_speed != lookup.min_speed) 358 dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n", 359 lookup.min_speed, lookup.force_speed); 360 return lookup.force_speed; 361 } else if (lookup.min_speed != UINT_MAX) { 362 return lookup.min_speed; 363 } else { 364 return 0; 365 } 366 } 367 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed); 368 369 static int i2c_acpi_find_match_adapter(struct device *dev, const void *data) 370 { 371 struct i2c_adapter *adapter = i2c_verify_adapter(dev); 372 373 if (!adapter) 374 return 0; 375 376 return ACPI_HANDLE(dev) == (acpi_handle)data; 377 } 378 379 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 380 { 381 struct device *dev; 382 383 dev = bus_find_device(&i2c_bus_type, NULL, handle, 384 i2c_acpi_find_match_adapter); 385 386 return dev ? i2c_verify_adapter(dev) : NULL; 387 } 388 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle); 389 390 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev) 391 { 392 struct device *dev; 393 struct i2c_client *client; 394 395 dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev); 396 if (!dev) 397 return NULL; 398 399 client = i2c_verify_client(dev); 400 if (!client) 401 put_device(dev); 402 403 return client; 404 } 405 406 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value, 407 void *arg) 408 { 409 struct acpi_device *adev = arg; 410 struct i2c_board_info info; 411 acpi_handle adapter_handle; 412 struct i2c_adapter *adapter; 413 struct i2c_client *client; 414 415 switch (value) { 416 case ACPI_RECONFIG_DEVICE_ADD: 417 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle)) 418 break; 419 420 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle); 421 if (!adapter) 422 break; 423 424 i2c_acpi_register_device(adapter, adev, &info); 425 break; 426 case ACPI_RECONFIG_DEVICE_REMOVE: 427 if (!acpi_device_enumerated(adev)) 428 break; 429 430 client = i2c_acpi_find_client_by_adev(adev); 431 if (!client) 432 break; 433 434 i2c_unregister_device(client); 435 put_device(&client->dev); 436 break; 437 } 438 439 return NOTIFY_OK; 440 } 441 442 struct notifier_block i2c_acpi_notifier = { 443 .notifier_call = i2c_acpi_notify, 444 }; 445 446 /** 447 * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource 448 * @dev: Device owning the ACPI resources to get the client from 449 * @index: Index of ACPI resource to get 450 * @info: describes the I2C device; note this is modified (addr gets set) 451 * Context: can sleep 452 * 453 * By default the i2c subsys creates an i2c-client for the first I2cSerialBus 454 * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus 455 * resources, in that case this function can be used to create an i2c-client 456 * for other I2cSerialBus resources in the Current Resource Settings table. 457 * 458 * Also see i2c_new_client_device, which this function calls to create the 459 * i2c-client. 460 * 461 * Returns a pointer to the new i2c-client, or error pointer in case of failure. 462 * Specifically, -EPROBE_DEFER is returned if the adapter is not found. 463 */ 464 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 465 struct i2c_board_info *info) 466 { 467 struct acpi_device *adev = ACPI_COMPANION(dev); 468 struct i2c_acpi_lookup lookup; 469 struct i2c_adapter *adapter; 470 LIST_HEAD(resource_list); 471 int ret; 472 473 memset(&lookup, 0, sizeof(lookup)); 474 lookup.info = info; 475 lookup.device_handle = acpi_device_handle(adev); 476 lookup.index = index; 477 478 ret = acpi_dev_get_resources(adev, &resource_list, 479 i2c_acpi_fill_info, &lookup); 480 if (ret < 0) 481 return ERR_PTR(ret); 482 483 acpi_dev_free_resource_list(&resource_list); 484 485 if (!info->addr) 486 return ERR_PTR(-EADDRNOTAVAIL); 487 488 adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle); 489 if (!adapter) 490 return ERR_PTR(-EPROBE_DEFER); 491 492 return i2c_new_client_device(adapter, info); 493 } 494 EXPORT_SYMBOL_GPL(i2c_acpi_new_device); 495 496 #ifdef CONFIG_ACPI_I2C_OPREGION 497 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client, 498 u8 cmd, u8 *data, u8 data_len) 499 { 500 501 struct i2c_msg msgs[2]; 502 int ret; 503 u8 *buffer; 504 505 buffer = kzalloc(data_len, GFP_KERNEL); 506 if (!buffer) 507 return AE_NO_MEMORY; 508 509 msgs[0].addr = client->addr; 510 msgs[0].flags = client->flags; 511 msgs[0].len = 1; 512 msgs[0].buf = &cmd; 513 514 msgs[1].addr = client->addr; 515 msgs[1].flags = client->flags | I2C_M_RD; 516 msgs[1].len = data_len; 517 msgs[1].buf = buffer; 518 519 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 520 if (ret < 0) { 521 /* Getting a NACK is unfortunately normal with some DSTDs */ 522 if (ret == -EREMOTEIO) 523 dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n", 524 data_len, client->addr, cmd, ret); 525 else 526 dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n", 527 data_len, client->addr, cmd, ret); 528 /* 2 transfers must have completed successfully */ 529 } else if (ret == 2) { 530 memcpy(data, buffer, data_len); 531 ret = 0; 532 } else { 533 ret = -EIO; 534 } 535 536 kfree(buffer); 537 return ret; 538 } 539 540 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client, 541 u8 cmd, u8 *data, u8 data_len) 542 { 543 544 struct i2c_msg msgs[1]; 545 u8 *buffer; 546 int ret = AE_OK; 547 548 buffer = kzalloc(data_len + 1, GFP_KERNEL); 549 if (!buffer) 550 return AE_NO_MEMORY; 551 552 buffer[0] = cmd; 553 memcpy(buffer + 1, data, data_len); 554 555 msgs[0].addr = client->addr; 556 msgs[0].flags = client->flags; 557 msgs[0].len = data_len + 1; 558 msgs[0].buf = buffer; 559 560 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 561 562 kfree(buffer); 563 564 if (ret < 0) { 565 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret); 566 return ret; 567 } 568 569 /* 1 transfer must have completed successfully */ 570 return (ret == 1) ? 0 : -EIO; 571 } 572 573 static acpi_status 574 i2c_acpi_space_handler(u32 function, acpi_physical_address command, 575 u32 bits, u64 *value64, 576 void *handler_context, void *region_context) 577 { 578 struct gsb_buffer *gsb = (struct gsb_buffer *)value64; 579 struct i2c_acpi_handler_data *data = handler_context; 580 struct acpi_connection_info *info = &data->info; 581 struct acpi_resource_i2c_serialbus *sb; 582 struct i2c_adapter *adapter = data->adapter; 583 struct i2c_client *client; 584 struct acpi_resource *ares; 585 u32 accessor_type = function >> 16; 586 u8 action = function & ACPI_IO_MASK; 587 acpi_status ret; 588 int status; 589 590 ret = acpi_buffer_to_resource(info->connection, info->length, &ares); 591 if (ACPI_FAILURE(ret)) 592 return ret; 593 594 client = kzalloc(sizeof(*client), GFP_KERNEL); 595 if (!client) { 596 ret = AE_NO_MEMORY; 597 goto err; 598 } 599 600 if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) { 601 ret = AE_BAD_PARAMETER; 602 goto err; 603 } 604 605 client->adapter = adapter; 606 client->addr = sb->slave_address; 607 608 if (sb->access_mode == ACPI_I2C_10BIT_MODE) 609 client->flags |= I2C_CLIENT_TEN; 610 611 switch (accessor_type) { 612 case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV: 613 if (action == ACPI_READ) { 614 status = i2c_smbus_read_byte(client); 615 if (status >= 0) { 616 gsb->bdata = status; 617 status = 0; 618 } 619 } else { 620 status = i2c_smbus_write_byte(client, gsb->bdata); 621 } 622 break; 623 624 case ACPI_GSB_ACCESS_ATTRIB_BYTE: 625 if (action == ACPI_READ) { 626 status = i2c_smbus_read_byte_data(client, command); 627 if (status >= 0) { 628 gsb->bdata = status; 629 status = 0; 630 } 631 } else { 632 status = i2c_smbus_write_byte_data(client, command, 633 gsb->bdata); 634 } 635 break; 636 637 case ACPI_GSB_ACCESS_ATTRIB_WORD: 638 if (action == ACPI_READ) { 639 status = i2c_smbus_read_word_data(client, command); 640 if (status >= 0) { 641 gsb->wdata = status; 642 status = 0; 643 } 644 } else { 645 status = i2c_smbus_write_word_data(client, command, 646 gsb->wdata); 647 } 648 break; 649 650 case ACPI_GSB_ACCESS_ATTRIB_BLOCK: 651 if (action == ACPI_READ) { 652 status = i2c_smbus_read_block_data(client, command, 653 gsb->data); 654 if (status >= 0) { 655 gsb->len = status; 656 status = 0; 657 } 658 } else { 659 status = i2c_smbus_write_block_data(client, command, 660 gsb->len, gsb->data); 661 } 662 break; 663 664 case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE: 665 if (action == ACPI_READ) { 666 status = acpi_gsb_i2c_read_bytes(client, command, 667 gsb->data, info->access_length); 668 } else { 669 status = acpi_gsb_i2c_write_bytes(client, command, 670 gsb->data, info->access_length); 671 } 672 break; 673 674 default: 675 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n", 676 accessor_type, client->addr); 677 ret = AE_BAD_PARAMETER; 678 goto err; 679 } 680 681 gsb->status = status; 682 683 err: 684 kfree(client); 685 ACPI_FREE(ares); 686 return ret; 687 } 688 689 690 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) 691 { 692 acpi_handle handle; 693 struct i2c_acpi_handler_data *data; 694 acpi_status status; 695 696 if (!adapter->dev.parent) 697 return -ENODEV; 698 699 handle = ACPI_HANDLE(adapter->dev.parent); 700 701 if (!handle) 702 return -ENODEV; 703 704 data = kzalloc(sizeof(struct i2c_acpi_handler_data), 705 GFP_KERNEL); 706 if (!data) 707 return -ENOMEM; 708 709 data->adapter = adapter; 710 status = acpi_bus_attach_private_data(handle, (void *)data); 711 if (ACPI_FAILURE(status)) { 712 kfree(data); 713 return -ENOMEM; 714 } 715 716 status = acpi_install_address_space_handler(handle, 717 ACPI_ADR_SPACE_GSBUS, 718 &i2c_acpi_space_handler, 719 NULL, 720 data); 721 if (ACPI_FAILURE(status)) { 722 dev_err(&adapter->dev, "Error installing i2c space handler\n"); 723 acpi_bus_detach_private_data(handle); 724 kfree(data); 725 return -ENOMEM; 726 } 727 728 return 0; 729 } 730 731 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) 732 { 733 acpi_handle handle; 734 struct i2c_acpi_handler_data *data; 735 acpi_status status; 736 737 if (!adapter->dev.parent) 738 return; 739 740 handle = ACPI_HANDLE(adapter->dev.parent); 741 742 if (!handle) 743 return; 744 745 acpi_remove_address_space_handler(handle, 746 ACPI_ADR_SPACE_GSBUS, 747 &i2c_acpi_space_handler); 748 749 status = acpi_bus_get_private_data(handle, (void **)&data); 750 if (ACPI_SUCCESS(status)) 751 kfree(data); 752 753 acpi_bus_detach_private_data(handle); 754 } 755 #endif /* CONFIG_ACPI_I2C_OPREGION */ 756