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_resource_count(struct acpi_resource *ares, void *data) 73 { 74 struct acpi_resource_i2c_serialbus *sb; 75 int *count = data; 76 77 if (i2c_acpi_get_i2c_resource(ares, &sb)) 78 *count = *count + 1; 79 80 return 1; 81 } 82 83 /** 84 * i2c_acpi_client_count - Count the number of I2cSerialBus resources 85 * @adev: ACPI device 86 * 87 * Returns the number of I2cSerialBus resources in the ACPI-device's 88 * resource-list; or a negative error code. 89 */ 90 int i2c_acpi_client_count(struct acpi_device *adev) 91 { 92 int ret, count = 0; 93 LIST_HEAD(r); 94 95 ret = acpi_dev_get_resources(adev, &r, i2c_acpi_resource_count, &count); 96 if (ret < 0) 97 return ret; 98 99 acpi_dev_free_resource_list(&r); 100 return count; 101 } 102 EXPORT_SYMBOL_GPL(i2c_acpi_client_count); 103 104 static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data) 105 { 106 struct i2c_acpi_lookup *lookup = data; 107 struct i2c_board_info *info = lookup->info; 108 struct acpi_resource_i2c_serialbus *sb; 109 acpi_status status; 110 111 if (info->addr || !i2c_acpi_get_i2c_resource(ares, &sb)) 112 return 1; 113 114 if (lookup->index != -1 && lookup->n++ != lookup->index) 115 return 1; 116 117 status = acpi_get_handle(lookup->device_handle, 118 sb->resource_source.string_ptr, 119 &lookup->adapter_handle); 120 if (ACPI_FAILURE(status)) 121 return 1; 122 123 info->addr = sb->slave_address; 124 lookup->speed = sb->connection_speed; 125 if (sb->access_mode == ACPI_I2C_10BIT_MODE) 126 info->flags |= I2C_CLIENT_TEN; 127 128 return 1; 129 } 130 131 static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = { 132 /* 133 * ACPI video acpi_devices, which are handled by the acpi-video driver 134 * sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these. 135 */ 136 { ACPI_VIDEO_HID, 0 }, 137 {} 138 }; 139 140 static int i2c_acpi_do_lookup(struct acpi_device *adev, 141 struct i2c_acpi_lookup *lookup) 142 { 143 struct i2c_board_info *info = lookup->info; 144 struct list_head resource_list; 145 int ret; 146 147 if (acpi_bus_get_status(adev) || !adev->status.present) 148 return -EINVAL; 149 150 if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0) 151 return -ENODEV; 152 153 memset(info, 0, sizeof(*info)); 154 lookup->device_handle = acpi_device_handle(adev); 155 156 /* Look up for I2cSerialBus resource */ 157 INIT_LIST_HEAD(&resource_list); 158 ret = acpi_dev_get_resources(adev, &resource_list, 159 i2c_acpi_fill_info, lookup); 160 acpi_dev_free_resource_list(&resource_list); 161 162 if (ret < 0 || !info->addr) 163 return -EINVAL; 164 165 return 0; 166 } 167 168 static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data) 169 { 170 int *irq = data; 171 struct resource r; 172 173 if (*irq <= 0 && acpi_dev_resource_interrupt(ares, 0, &r)) 174 *irq = i2c_dev_irq_from_resources(&r, 1); 175 176 return 1; /* No need to add resource to the list */ 177 } 178 179 /** 180 * i2c_acpi_get_irq - get device IRQ number from ACPI 181 * @client: Pointer to the I2C client device 182 * 183 * Find the IRQ number used by a specific client device. 184 * 185 * Return: The IRQ number or an error code. 186 */ 187 int i2c_acpi_get_irq(struct i2c_client *client) 188 { 189 struct acpi_device *adev = ACPI_COMPANION(&client->dev); 190 struct list_head resource_list; 191 int irq = -ENOENT; 192 int ret; 193 194 INIT_LIST_HEAD(&resource_list); 195 196 ret = acpi_dev_get_resources(adev, &resource_list, 197 i2c_acpi_add_resource, &irq); 198 if (ret < 0) 199 return ret; 200 201 acpi_dev_free_resource_list(&resource_list); 202 203 if (irq == -ENOENT) 204 irq = acpi_dev_gpio_irq_get(adev, 0); 205 206 return irq; 207 } 208 209 static int i2c_acpi_get_info(struct acpi_device *adev, 210 struct i2c_board_info *info, 211 struct i2c_adapter *adapter, 212 acpi_handle *adapter_handle) 213 { 214 struct i2c_acpi_lookup lookup; 215 int ret; 216 217 memset(&lookup, 0, sizeof(lookup)); 218 lookup.info = info; 219 lookup.index = -1; 220 221 if (acpi_device_enumerated(adev)) 222 return -EINVAL; 223 224 ret = i2c_acpi_do_lookup(adev, &lookup); 225 if (ret) 226 return ret; 227 228 if (adapter) { 229 /* The adapter must match the one in I2cSerialBus() connector */ 230 if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle) 231 return -ENODEV; 232 } else { 233 struct acpi_device *adapter_adev; 234 235 /* The adapter must be present */ 236 if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev)) 237 return -ENODEV; 238 if (acpi_bus_get_status(adapter_adev) || 239 !adapter_adev->status.present) 240 return -ENODEV; 241 } 242 243 info->fwnode = acpi_fwnode_handle(adev); 244 if (adapter_handle) 245 *adapter_handle = lookup.adapter_handle; 246 247 acpi_set_modalias(adev, dev_name(&adev->dev), info->type, 248 sizeof(info->type)); 249 250 return 0; 251 } 252 253 static void i2c_acpi_register_device(struct i2c_adapter *adapter, 254 struct acpi_device *adev, 255 struct i2c_board_info *info) 256 { 257 adev->power.flags.ignore_parent = true; 258 acpi_device_set_enumerated(adev); 259 260 if (IS_ERR(i2c_new_client_device(adapter, info))) 261 adev->power.flags.ignore_parent = false; 262 } 263 264 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level, 265 void *data, void **return_value) 266 { 267 struct i2c_adapter *adapter = data; 268 struct acpi_device *adev; 269 struct i2c_board_info info; 270 271 if (acpi_bus_get_device(handle, &adev)) 272 return AE_OK; 273 274 if (i2c_acpi_get_info(adev, &info, adapter, NULL)) 275 return AE_OK; 276 277 i2c_acpi_register_device(adapter, adev, &info); 278 279 return AE_OK; 280 } 281 282 #define I2C_ACPI_MAX_SCAN_DEPTH 32 283 284 /** 285 * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter 286 * @adap: pointer to adapter 287 * 288 * Enumerate all I2C slave devices behind this adapter by walking the ACPI 289 * namespace. When a device is found it will be added to the Linux device 290 * model and bound to the corresponding ACPI handle. 291 */ 292 void i2c_acpi_register_devices(struct i2c_adapter *adap) 293 { 294 struct acpi_device *adev; 295 acpi_status status; 296 297 if (!has_acpi_companion(&adap->dev)) 298 return; 299 300 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 301 I2C_ACPI_MAX_SCAN_DEPTH, 302 i2c_acpi_add_device, NULL, 303 adap, NULL); 304 if (ACPI_FAILURE(status)) 305 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n"); 306 307 if (!adap->dev.parent) 308 return; 309 310 adev = ACPI_COMPANION(adap->dev.parent); 311 if (!adev) 312 return; 313 314 acpi_dev_clear_dependencies(adev); 315 } 316 317 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = { 318 /* 319 * These Silead touchscreen controllers only work at 400KHz, for 320 * some reason they do not work at 100KHz. On some devices the ACPI 321 * tables list another device at their bus as only being capable 322 * of 100KHz, testing has shown that these other devices work fine 323 * at 400KHz (as can be expected of any recent i2c hw) so we force 324 * the speed of the bus to 400 KHz if a Silead device is present. 325 */ 326 { "MSSL1680", 0 }, 327 {} 328 }; 329 330 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level, 331 void *data, void **return_value) 332 { 333 struct i2c_acpi_lookup *lookup = data; 334 struct acpi_device *adev; 335 336 if (acpi_bus_get_device(handle, &adev)) 337 return AE_OK; 338 339 if (i2c_acpi_do_lookup(adev, lookup)) 340 return AE_OK; 341 342 if (lookup->search_handle != lookup->adapter_handle) 343 return AE_OK; 344 345 if (lookup->speed <= lookup->min_speed) 346 lookup->min_speed = lookup->speed; 347 348 if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0) 349 lookup->force_speed = I2C_MAX_FAST_MODE_FREQ; 350 351 return AE_OK; 352 } 353 354 /** 355 * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI 356 * @dev: The device owning the bus 357 * 358 * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves 359 * devices connected to this bus and use the speed of slowest device. 360 * 361 * Returns the speed in Hz or zero 362 */ 363 u32 i2c_acpi_find_bus_speed(struct device *dev) 364 { 365 struct i2c_acpi_lookup lookup; 366 struct i2c_board_info dummy; 367 acpi_status status; 368 369 if (!has_acpi_companion(dev)) 370 return 0; 371 372 memset(&lookup, 0, sizeof(lookup)); 373 lookup.search_handle = ACPI_HANDLE(dev); 374 lookup.min_speed = UINT_MAX; 375 lookup.info = &dummy; 376 lookup.index = -1; 377 378 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 379 I2C_ACPI_MAX_SCAN_DEPTH, 380 i2c_acpi_lookup_speed, NULL, 381 &lookup, NULL); 382 383 if (ACPI_FAILURE(status)) { 384 dev_warn(dev, "unable to find I2C bus speed from ACPI\n"); 385 return 0; 386 } 387 388 if (lookup.force_speed) { 389 if (lookup.force_speed != lookup.min_speed) 390 dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n", 391 lookup.min_speed, lookup.force_speed); 392 return lookup.force_speed; 393 } else if (lookup.min_speed != UINT_MAX) { 394 return lookup.min_speed; 395 } else { 396 return 0; 397 } 398 } 399 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed); 400 401 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 402 { 403 struct i2c_adapter *adapter; 404 struct device *dev; 405 406 dev = bus_find_device(&i2c_bus_type, NULL, handle, device_match_acpi_handle); 407 if (!dev) 408 return NULL; 409 410 adapter = i2c_verify_adapter(dev); 411 if (!adapter) 412 put_device(dev); 413 414 return adapter; 415 } 416 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle); 417 418 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev) 419 { 420 struct device *dev; 421 struct i2c_client *client; 422 423 dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev); 424 if (!dev) 425 return NULL; 426 427 client = i2c_verify_client(dev); 428 if (!client) 429 put_device(dev); 430 431 return client; 432 } 433 434 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value, 435 void *arg) 436 { 437 struct acpi_device *adev = arg; 438 struct i2c_board_info info; 439 acpi_handle adapter_handle; 440 struct i2c_adapter *adapter; 441 struct i2c_client *client; 442 443 switch (value) { 444 case ACPI_RECONFIG_DEVICE_ADD: 445 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle)) 446 break; 447 448 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle); 449 if (!adapter) 450 break; 451 452 i2c_acpi_register_device(adapter, adev, &info); 453 put_device(&adapter->dev); 454 break; 455 case ACPI_RECONFIG_DEVICE_REMOVE: 456 if (!acpi_device_enumerated(adev)) 457 break; 458 459 client = i2c_acpi_find_client_by_adev(adev); 460 if (!client) 461 break; 462 463 i2c_unregister_device(client); 464 put_device(&client->dev); 465 break; 466 } 467 468 return NOTIFY_OK; 469 } 470 471 struct notifier_block i2c_acpi_notifier = { 472 .notifier_call = i2c_acpi_notify, 473 }; 474 475 /** 476 * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource 477 * @dev: Device owning the ACPI resources to get the client from 478 * @index: Index of ACPI resource to get 479 * @info: describes the I2C device; note this is modified (addr gets set) 480 * Context: can sleep 481 * 482 * By default the i2c subsys creates an i2c-client for the first I2cSerialBus 483 * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus 484 * resources, in that case this function can be used to create an i2c-client 485 * for other I2cSerialBus resources in the Current Resource Settings table. 486 * 487 * Also see i2c_new_client_device, which this function calls to create the 488 * i2c-client. 489 * 490 * Returns a pointer to the new i2c-client, or error pointer in case of failure. 491 * Specifically, -EPROBE_DEFER is returned if the adapter is not found. 492 */ 493 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 494 struct i2c_board_info *info) 495 { 496 struct acpi_device *adev = ACPI_COMPANION(dev); 497 struct i2c_acpi_lookup lookup; 498 struct i2c_adapter *adapter; 499 LIST_HEAD(resource_list); 500 int ret; 501 502 memset(&lookup, 0, sizeof(lookup)); 503 lookup.info = info; 504 lookup.device_handle = acpi_device_handle(adev); 505 lookup.index = index; 506 507 ret = acpi_dev_get_resources(adev, &resource_list, 508 i2c_acpi_fill_info, &lookup); 509 if (ret < 0) 510 return ERR_PTR(ret); 511 512 acpi_dev_free_resource_list(&resource_list); 513 514 if (!info->addr) 515 return ERR_PTR(-EADDRNOTAVAIL); 516 517 adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle); 518 if (!adapter) 519 return ERR_PTR(-EPROBE_DEFER); 520 521 return i2c_new_client_device(adapter, info); 522 } 523 EXPORT_SYMBOL_GPL(i2c_acpi_new_device); 524 525 bool i2c_acpi_waive_d0_probe(struct device *dev) 526 { 527 struct i2c_driver *driver = to_i2c_driver(dev->driver); 528 struct acpi_device *adev = ACPI_COMPANION(dev); 529 530 return driver->flags & I2C_DRV_ACPI_WAIVE_D0_PROBE && 531 adev && adev->power.state_for_enumeration >= adev->power.state; 532 } 533 EXPORT_SYMBOL_GPL(i2c_acpi_waive_d0_probe); 534 535 #ifdef CONFIG_ACPI_I2C_OPREGION 536 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client, 537 u8 cmd, u8 *data, u8 data_len) 538 { 539 540 struct i2c_msg msgs[2]; 541 int ret; 542 u8 *buffer; 543 544 buffer = kzalloc(data_len, GFP_KERNEL); 545 if (!buffer) 546 return AE_NO_MEMORY; 547 548 msgs[0].addr = client->addr; 549 msgs[0].flags = client->flags; 550 msgs[0].len = 1; 551 msgs[0].buf = &cmd; 552 553 msgs[1].addr = client->addr; 554 msgs[1].flags = client->flags | I2C_M_RD; 555 msgs[1].len = data_len; 556 msgs[1].buf = buffer; 557 558 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 559 if (ret < 0) { 560 /* Getting a NACK is unfortunately normal with some DSTDs */ 561 if (ret == -EREMOTEIO) 562 dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n", 563 data_len, client->addr, cmd, ret); 564 else 565 dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n", 566 data_len, client->addr, cmd, ret); 567 /* 2 transfers must have completed successfully */ 568 } else if (ret == 2) { 569 memcpy(data, buffer, data_len); 570 ret = 0; 571 } else { 572 ret = -EIO; 573 } 574 575 kfree(buffer); 576 return ret; 577 } 578 579 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client, 580 u8 cmd, u8 *data, u8 data_len) 581 { 582 583 struct i2c_msg msgs[1]; 584 u8 *buffer; 585 int ret = AE_OK; 586 587 buffer = kzalloc(data_len + 1, GFP_KERNEL); 588 if (!buffer) 589 return AE_NO_MEMORY; 590 591 buffer[0] = cmd; 592 memcpy(buffer + 1, data, data_len); 593 594 msgs[0].addr = client->addr; 595 msgs[0].flags = client->flags; 596 msgs[0].len = data_len + 1; 597 msgs[0].buf = buffer; 598 599 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 600 601 kfree(buffer); 602 603 if (ret < 0) { 604 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret); 605 return ret; 606 } 607 608 /* 1 transfer must have completed successfully */ 609 return (ret == 1) ? 0 : -EIO; 610 } 611 612 static acpi_status 613 i2c_acpi_space_handler(u32 function, acpi_physical_address command, 614 u32 bits, u64 *value64, 615 void *handler_context, void *region_context) 616 { 617 struct gsb_buffer *gsb = (struct gsb_buffer *)value64; 618 struct i2c_acpi_handler_data *data = handler_context; 619 struct acpi_connection_info *info = &data->info; 620 struct acpi_resource_i2c_serialbus *sb; 621 struct i2c_adapter *adapter = data->adapter; 622 struct i2c_client *client; 623 struct acpi_resource *ares; 624 u32 accessor_type = function >> 16; 625 u8 action = function & ACPI_IO_MASK; 626 acpi_status ret; 627 int status; 628 629 ret = acpi_buffer_to_resource(info->connection, info->length, &ares); 630 if (ACPI_FAILURE(ret)) 631 return ret; 632 633 client = kzalloc(sizeof(*client), GFP_KERNEL); 634 if (!client) { 635 ret = AE_NO_MEMORY; 636 goto err; 637 } 638 639 if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) { 640 ret = AE_BAD_PARAMETER; 641 goto err; 642 } 643 644 client->adapter = adapter; 645 client->addr = sb->slave_address; 646 647 if (sb->access_mode == ACPI_I2C_10BIT_MODE) 648 client->flags |= I2C_CLIENT_TEN; 649 650 switch (accessor_type) { 651 case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV: 652 if (action == ACPI_READ) { 653 status = i2c_smbus_read_byte(client); 654 if (status >= 0) { 655 gsb->bdata = status; 656 status = 0; 657 } 658 } else { 659 status = i2c_smbus_write_byte(client, gsb->bdata); 660 } 661 break; 662 663 case ACPI_GSB_ACCESS_ATTRIB_BYTE: 664 if (action == ACPI_READ) { 665 status = i2c_smbus_read_byte_data(client, command); 666 if (status >= 0) { 667 gsb->bdata = status; 668 status = 0; 669 } 670 } else { 671 status = i2c_smbus_write_byte_data(client, command, 672 gsb->bdata); 673 } 674 break; 675 676 case ACPI_GSB_ACCESS_ATTRIB_WORD: 677 if (action == ACPI_READ) { 678 status = i2c_smbus_read_word_data(client, command); 679 if (status >= 0) { 680 gsb->wdata = status; 681 status = 0; 682 } 683 } else { 684 status = i2c_smbus_write_word_data(client, command, 685 gsb->wdata); 686 } 687 break; 688 689 case ACPI_GSB_ACCESS_ATTRIB_BLOCK: 690 if (action == ACPI_READ) { 691 status = i2c_smbus_read_block_data(client, command, 692 gsb->data); 693 if (status >= 0) { 694 gsb->len = status; 695 status = 0; 696 } 697 } else { 698 status = i2c_smbus_write_block_data(client, command, 699 gsb->len, gsb->data); 700 } 701 break; 702 703 case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE: 704 if (action == ACPI_READ) { 705 status = acpi_gsb_i2c_read_bytes(client, command, 706 gsb->data, info->access_length); 707 } else { 708 status = acpi_gsb_i2c_write_bytes(client, command, 709 gsb->data, info->access_length); 710 } 711 break; 712 713 default: 714 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n", 715 accessor_type, client->addr); 716 ret = AE_BAD_PARAMETER; 717 goto err; 718 } 719 720 gsb->status = status; 721 722 err: 723 kfree(client); 724 ACPI_FREE(ares); 725 return ret; 726 } 727 728 729 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) 730 { 731 acpi_handle handle; 732 struct i2c_acpi_handler_data *data; 733 acpi_status status; 734 735 if (!adapter->dev.parent) 736 return -ENODEV; 737 738 handle = ACPI_HANDLE(adapter->dev.parent); 739 740 if (!handle) 741 return -ENODEV; 742 743 data = kzalloc(sizeof(struct i2c_acpi_handler_data), 744 GFP_KERNEL); 745 if (!data) 746 return -ENOMEM; 747 748 data->adapter = adapter; 749 status = acpi_bus_attach_private_data(handle, (void *)data); 750 if (ACPI_FAILURE(status)) { 751 kfree(data); 752 return -ENOMEM; 753 } 754 755 status = acpi_install_address_space_handler(handle, 756 ACPI_ADR_SPACE_GSBUS, 757 &i2c_acpi_space_handler, 758 NULL, 759 data); 760 if (ACPI_FAILURE(status)) { 761 dev_err(&adapter->dev, "Error installing i2c space handler\n"); 762 acpi_bus_detach_private_data(handle); 763 kfree(data); 764 return -ENOMEM; 765 } 766 767 return 0; 768 } 769 770 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) 771 { 772 acpi_handle handle; 773 struct i2c_acpi_handler_data *data; 774 acpi_status status; 775 776 if (!adapter->dev.parent) 777 return; 778 779 handle = ACPI_HANDLE(adapter->dev.parent); 780 781 if (!handle) 782 return; 783 784 acpi_remove_address_space_handler(handle, 785 ACPI_ADR_SPACE_GSBUS, 786 &i2c_acpi_space_handler); 787 788 status = acpi_bus_get_private_data(handle, (void **)&data); 789 if (ACPI_SUCCESS(status)) 790 kfree(data); 791 792 acpi_bus_detach_private_data(handle); 793 } 794 #endif /* CONFIG_ACPI_I2C_OPREGION */ 795