drivers/i2c/i2c-core-acpi.c

   1 /*
   2  * Linux I2C core ACPI support code
   3  *
   4  * Copyright (C) 2014 Intel Corp, Author: Lan Tianyu <tianyu.lan@intel.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  */
  11
  12 #include <linux/acpi.h>
  13 #include <linux/device.h>
  14 #include <linux/err.h>
  15 #include <linux/i2c.h>
  16 #include <linux/list.h>
  17 #include <linux/module.h>
  18 #include <linux/slab.h>
  19
  20 #include "i2c-core.h"
  21
  22 struct i2c_acpi_handler_data {
  23         struct acpi_connection_info info;
  24         struct i2c_adapter *adapter;
  25 };
  26
  27 struct gsb_buffer {
  28         u8      status;
  29         u8      len;
  30         union {
  31                 u16     wdata;
  32                 u8      bdata;
  33                 u8      data[0];
  34         };
  35 } __packed;
  36
  37 struct i2c_acpi_lookup {
  38         struct i2c_board_info *info;
  39         acpi_handle adapter_handle;
  40         acpi_handle device_handle;
  41         acpi_handle search_handle;
  42         int n;
  43         int index;
  44         u32 speed;
  45         u32 min_speed;
  46         u32 force_speed;
  47 };
  48
  49 static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
  50 {
  51         struct i2c_acpi_lookup *lookup = data;
  52         struct i2c_board_info *info = lookup->info;
  53         struct acpi_resource_i2c_serialbus *sb;
  54         acpi_status status;
  55
  56         if (info->addr || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
  57                 return 1;
  58
  59         sb = &ares->data.i2c_serial_bus;
  60         if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
  61                 return 1;
  62
  63         if (lookup->index != -1 && lookup->n++ != lookup->index)
  64                 return 1;
  65
  66         status = acpi_get_handle(lookup->device_handle,
  67                                  sb->resource_source.string_ptr,
  68                                  &lookup->adapter_handle);
  69         if (!ACPI_SUCCESS(status))
  70                 return 1;
  71
  72         info->addr = sb->slave_address;
  73         lookup->speed = sb->connection_speed;
  74         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
  75                 info->flags |= I2C_CLIENT_TEN;
  76
  77         return 1;
  78 }
  79
  80 static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
  81         /*
  82          * ACPI video acpi_devices, which are handled by the acpi-video driver
  83          * sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these.
  84          */
  85         { ACPI_VIDEO_HID, 0 },
  86         {}
  87 };
  88
  89 static int i2c_acpi_do_lookup(struct acpi_device *adev,
  90                               struct i2c_acpi_lookup *lookup)
  91 {
  92         struct i2c_board_info *info = lookup->info;
  93         struct list_head resource_list;
  94         int ret;
  95
  96         if (acpi_bus_get_status(adev) || !adev->status.present ||
  97             acpi_device_enumerated(adev))
  98                 return -EINVAL;
  99
 100         if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)
 101                 return -ENODEV;
 102
 103         memset(info, 0, sizeof(*info));
 104         lookup->device_handle = acpi_device_handle(adev);
 105
 106         /* Look up for I2cSerialBus resource */
 107         INIT_LIST_HEAD(&resource_list);
 108         ret = acpi_dev_get_resources(adev, &resource_list,
 109                                      i2c_acpi_fill_info, lookup);
 110         acpi_dev_free_resource_list(&resource_list);
 111
 112         if (ret < 0 || !info->addr)
 113                 return -EINVAL;
 114
 115         return 0;
 116 }
 117
 118 static int i2c_acpi_get_info(struct acpi_device *adev,
 119                              struct i2c_board_info *info,
 120                              struct i2c_adapter *adapter,
 121                              acpi_handle *adapter_handle)
 122 {
 123         struct list_head resource_list;
 124         struct resource_entry *entry;
 125         struct i2c_acpi_lookup lookup;
 126         int ret;
 127
 128         memset(&lookup, 0, sizeof(lookup));
 129         lookup.info = info;
 130         lookup.index = -1;
 131
 132         ret = i2c_acpi_do_lookup(adev, &lookup);
 133         if (ret)
 134                 return ret;
 135
 136         if (adapter) {
 137                 /* The adapter must match the one in I2cSerialBus() connector */
 138                 if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
 139                         return -ENODEV;
 140         } else {
 141                 struct acpi_device *adapter_adev;
 142
 143                 /* The adapter must be present */
 144                 if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
 145                         return -ENODEV;
 146                 if (acpi_bus_get_status(adapter_adev) ||
 147                     !adapter_adev->status.present)
 148                         return -ENODEV;
 149         }
 150
 151         info->fwnode = acpi_fwnode_handle(adev);
 152         if (adapter_handle)
 153                 *adapter_handle = lookup.adapter_handle;
 154
 155         /* Then fill IRQ number if any */
 156         INIT_LIST_HEAD(&resource_list);
 157         ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
 158         if (ret < 0)
 159                 return -EINVAL;
 160
 161         resource_list_for_each_entry(entry, &resource_list) {
 162                 if (resource_type(entry->res) == IORESOURCE_IRQ) {
 163                         info->irq = entry->res->start;
 164                         break;
 165                 }
 166         }
 167
 168         acpi_dev_free_resource_list(&resource_list);
 169
 170         acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
 171                           sizeof(info->type));
 172
 173         return 0;
 174 }
 175
 176 static void i2c_acpi_register_device(struct i2c_adapter *adapter,
 177                                      struct acpi_device *adev,
 178                                      struct i2c_board_info *info)
 179 {
 180         adev->power.flags.ignore_parent = true;
 181         acpi_device_set_enumerated(adev);
 182
 183         if (!i2c_new_device(adapter, info)) {
 184                 adev->power.flags.ignore_parent = false;
 185                 dev_err(&adapter->dev,
 186                         "failed to add I2C device %s from ACPI\n",
 187                         dev_name(&adev->dev));
 188         }
 189 }
 190
 191 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
 192                                        void *data, void **return_value)
 193 {
 194         struct i2c_adapter *adapter = data;
 195         struct acpi_device *adev;
 196         struct i2c_board_info info;
 197
 198         if (acpi_bus_get_device(handle, &adev))
 199                 return AE_OK;
 200
 201         if (i2c_acpi_get_info(adev, &info, adapter, NULL))
 202                 return AE_OK;
 203
 204         i2c_acpi_register_device(adapter, adev, &info);
 205
 206         return AE_OK;
 207 }
 208
 209 #define I2C_ACPI_MAX_SCAN_DEPTH 32
 210
 211 /**
 212  * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
 213  * @adap: pointer to adapter
 214  *
 215  * Enumerate all I2C slave devices behind this adapter by walking the ACPI
 216  * namespace. When a device is found it will be added to the Linux device
 217  * model and bound to the corresponding ACPI handle.
 218  */
 219 void i2c_acpi_register_devices(struct i2c_adapter *adap)
 220 {
 221         acpi_status status;
 222
 223         if (!has_acpi_companion(&adap->dev))
 224                 return;
 225
 226         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 227                                      I2C_ACPI_MAX_SCAN_DEPTH,
 228                                      i2c_acpi_add_device, NULL,
 229                                      adap, NULL);
 230         if (ACPI_FAILURE(status))
 231                 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
 232 }
 233
 234 const struct acpi_device_id *
 235 i2c_acpi_match_device(const struct acpi_device_id *matches,
 236                       struct i2c_client *client)
 237 {
 238         if (!(client && matches))
 239                 return NULL;
 240
 241         return acpi_match_device(matches, &client->dev);
 242 }
 243
 244 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
 245         /*
 246          * These Silead touchscreen controllers only work at 400KHz, for
 247          * some reason they do not work at 100KHz. On some devices the ACPI
 248          * tables list another device at their bus as only being capable
 249          * of 100KHz, testing has shown that these other devices work fine
 250          * at 400KHz (as can be expected of any recent i2c hw) so we force
 251          * the speed of the bus to 400 KHz if a Silead device is present.
 252          */
 253         { "MSSL1680", 0 },
 254         {}
 255 };
 256
 257 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
 258                                            void *data, void **return_value)
 259 {
 260         struct i2c_acpi_lookup *lookup = data;
 261         struct acpi_device *adev;
 262
 263         if (acpi_bus_get_device(handle, &adev))
 264                 return AE_OK;
 265
 266         if (i2c_acpi_do_lookup(adev, lookup))
 267                 return AE_OK;
 268
 269         if (lookup->search_handle != lookup->adapter_handle)
 270                 return AE_OK;
 271
 272         if (lookup->speed <= lookup->min_speed)
 273                 lookup->min_speed = lookup->speed;
 274
 275         if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
 276                 lookup->force_speed = 400000;
 277
 278         return AE_OK;
 279 }
 280
 281 /**
 282  * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
 283  * @dev: The device owning the bus
 284  *
 285  * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
 286  * devices connected to this bus and use the speed of slowest device.
 287  *
 288  * Returns the speed in Hz or zero
 289  */
 290 u32 i2c_acpi_find_bus_speed(struct device *dev)
 291 {
 292         struct i2c_acpi_lookup lookup;
 293         struct i2c_board_info dummy;
 294         acpi_status status;
 295
 296         if (!has_acpi_companion(dev))
 297                 return 0;
 298
 299         memset(&lookup, 0, sizeof(lookup));
 300         lookup.search_handle = ACPI_HANDLE(dev);
 301         lookup.min_speed = UINT_MAX;
 302         lookup.info = &dummy;
 303         lookup.index = -1;
 304
 305         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 306                                      I2C_ACPI_MAX_SCAN_DEPTH,
 307                                      i2c_acpi_lookup_speed, NULL,
 308                                      &lookup, NULL);
 309
 310         if (ACPI_FAILURE(status)) {
 311                 dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
 312                 return 0;
 313         }
 314
 315         if (lookup.force_speed) {
 316                 if (lookup.force_speed != lookup.min_speed)
 317                         dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
 318                                  lookup.min_speed, lookup.force_speed);
 319                 return lookup.force_speed;
 320         } else if (lookup.min_speed != UINT_MAX) {
 321                 return lookup.min_speed;
 322         } else {
 323                 return 0;
 324         }
 325 }
 326 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
 327
 328 static int i2c_acpi_find_match_adapter(struct device *dev, void *data)
 329 {
 330         struct i2c_adapter *adapter = i2c_verify_adapter(dev);
 331
 332         if (!adapter)
 333                 return 0;
 334
 335         return ACPI_HANDLE(dev) == (acpi_handle)data;
 336 }
 337
 338 static int i2c_acpi_find_match_device(struct device *dev, void *data)
 339 {
 340         return ACPI_COMPANION(dev) == data;
 341 }
 342
 343 static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 344 {
 345         struct device *dev;
 346
 347         dev = bus_find_device(&i2c_bus_type, NULL, handle,
 348                               i2c_acpi_find_match_adapter);
 349         return dev ? i2c_verify_adapter(dev) : NULL;
 350 }
 351
 352 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 353 {
 354         struct device *dev;
 355         struct i2c_client *client;
 356
 357         dev = bus_find_device(&i2c_bus_type, NULL, adev,
 358                               i2c_acpi_find_match_device);
 359         if (!dev)
 360                 return NULL;
 361
 362         client = i2c_verify_client(dev);
 363         if (!client)
 364                 put_device(dev);
 365
 366         return client;
 367 }
 368
 369 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
 370                            void *arg)
 371 {
 372         struct acpi_device *adev = arg;
 373         struct i2c_board_info info;
 374         acpi_handle adapter_handle;
 375         struct i2c_adapter *adapter;
 376         struct i2c_client *client;
 377
 378         switch (value) {
 379         case ACPI_RECONFIG_DEVICE_ADD:
 380                 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
 381                         break;
 382
 383                 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
 384                 if (!adapter)
 385                         break;
 386
 387                 i2c_acpi_register_device(adapter, adev, &info);
 388                 break;
 389         case ACPI_RECONFIG_DEVICE_REMOVE:
 390                 if (!acpi_device_enumerated(adev))
 391                         break;
 392
 393                 client = i2c_acpi_find_client_by_adev(adev);
 394                 if (!client)
 395                         break;
 396
 397                 i2c_unregister_device(client);
 398                 put_device(&client->dev);
 399                 break;
 400         }
 401
 402         return NOTIFY_OK;
 403 }
 404
 405 struct notifier_block i2c_acpi_notifier = {
 406         .notifier_call = i2c_acpi_notify,
 407 };
 408
 409 /**
 410  * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
 411  * @dev:     Device owning the ACPI resources to get the client from
 412  * @index:   Index of ACPI resource to get
 413  * @info:    describes the I2C device; note this is modified (addr gets set)
 414  * Context: can sleep
 415  *
 416  * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
 417  * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
 418  * resources, in that case this function can be used to create an i2c-client
 419  * for other I2cSerialBus resources in the Current Resource Settings table.
 420  *
 421  * Also see i2c_new_device, which this function calls to create the i2c-client.
 422  *
 423  * Returns a pointer to the new i2c-client, or NULL if the adapter is not found.
 424  */
 425 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
 426                                        struct i2c_board_info *info)
 427 {
 428         struct i2c_acpi_lookup lookup;
 429         struct i2c_adapter *adapter;
 430         struct acpi_device *adev;
 431         LIST_HEAD(resource_list);
 432         int ret;
 433
 434         adev = ACPI_COMPANION(dev);
 435         if (!adev)
 436                 return NULL;
 437
 438         memset(&lookup, 0, sizeof(lookup));
 439         lookup.info = info;
 440         lookup.device_handle = acpi_device_handle(adev);
 441         lookup.index = index;
 442
 443         ret = acpi_dev_get_resources(adev, &resource_list,
 444                                      i2c_acpi_fill_info, &lookup);
 445         acpi_dev_free_resource_list(&resource_list);
 446
 447         if (ret < 0 || !info->addr)
 448                 return NULL;
 449
 450         adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
 451         if (!adapter)
 452                 return NULL;
 453
 454         return i2c_new_device(adapter, info);
 455 }
 456 EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
 457
 458 #ifdef CONFIG_ACPI_I2C_OPREGION
 459 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
 460                 u8 cmd, u8 *data, u8 data_len)
 461 {
 462
 463         struct i2c_msg msgs[2];
 464         int ret;
 465         u8 *buffer;
 466
 467         buffer = kzalloc(data_len, GFP_KERNEL);
 468         if (!buffer)
 469                 return AE_NO_MEMORY;
 470
 471         msgs[0].addr = client->addr;
 472         msgs[0].flags = client->flags;
 473         msgs[0].len = 1;
 474         msgs[0].buf = &cmd;
 475
 476         msgs[1].addr = client->addr;
 477         msgs[1].flags = client->flags | I2C_M_RD;
 478         msgs[1].len = data_len;
 479         msgs[1].buf = buffer;
 480
 481         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 482         if (ret < 0) {
 483                 /* Getting a NACK is unfortunately normal with some DSTDs */
 484                 if (ret == -EREMOTEIO)
 485                         dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 486                                 data_len, client->addr, cmd, ret);
 487                 else
 488                         dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 489                                 data_len, client->addr, cmd, ret);
 490         /* 2 transfers must have completed successfully */
 491         } else if (ret == 2) {
 492                 memcpy(data, buffer, data_len);
 493                 ret = 0;
 494         } else {
 495                 ret = -EIO;
 496         }
 497
 498         kfree(buffer);
 499         return ret;
 500 }
 501
 502 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
 503                 u8 cmd, u8 *data, u8 data_len)
 504 {
 505
 506         struct i2c_msg msgs[1];
 507         u8 *buffer;
 508         int ret = AE_OK;
 509
 510         buffer = kzalloc(data_len + 1, GFP_KERNEL);
 511         if (!buffer)
 512                 return AE_NO_MEMORY;
 513
 514         buffer[0] = cmd;
 515         memcpy(buffer + 1, data, data_len);
 516
 517         msgs[0].addr = client->addr;
 518         msgs[0].flags = client->flags;
 519         msgs[0].len = data_len + 1;
 520         msgs[0].buf = buffer;
 521
 522         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 523
 524         kfree(buffer);
 525
 526         if (ret < 0) {
 527                 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
 528                 return ret;
 529         }
 530
 531         /* 1 transfer must have completed successfully */
 532         return (ret == 1) ? 0 : -EIO;
 533 }
 534
 535 static acpi_status
 536 i2c_acpi_space_handler(u32 function, acpi_physical_address command,
 537                         u32 bits, u64 *value64,
 538                         void *handler_context, void *region_context)
 539 {
 540         struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
 541         struct i2c_acpi_handler_data *data = handler_context;
 542         struct acpi_connection_info *info = &data->info;
 543         struct acpi_resource_i2c_serialbus *sb;
 544         struct i2c_adapter *adapter = data->adapter;
 545         struct i2c_client *client;
 546         struct acpi_resource *ares;
 547         u32 accessor_type = function >> 16;
 548         u8 action = function & ACPI_IO_MASK;
 549         acpi_status ret;
 550         int status;
 551
 552         ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
 553         if (ACPI_FAILURE(ret))
 554                 return ret;
 555
 556         client = kzalloc(sizeof(*client), GFP_KERNEL);
 557         if (!client) {
 558                 ret = AE_NO_MEMORY;
 559                 goto err;
 560         }
 561
 562         if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) {
 563                 ret = AE_BAD_PARAMETER;
 564                 goto err;
 565         }
 566
 567         sb = &ares->data.i2c_serial_bus;
 568         if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) {
 569                 ret = AE_BAD_PARAMETER;
 570                 goto err;
 571         }
 572
 573         client->adapter = adapter;
 574         client->addr = sb->slave_address;
 575
 576         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
 577                 client->flags |= I2C_CLIENT_TEN;
 578
 579         switch (accessor_type) {
 580         case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
 581                 if (action == ACPI_READ) {
 582                         status = i2c_smbus_read_byte(client);
 583                         if (status >= 0) {
 584                                 gsb->bdata = status;
 585                                 status = 0;
 586                         }
 587                 } else {
 588                         status = i2c_smbus_write_byte(client, gsb->bdata);
 589                 }
 590                 break;
 591
 592         case ACPI_GSB_ACCESS_ATTRIB_BYTE:
 593                 if (action == ACPI_READ) {
 594                         status = i2c_smbus_read_byte_data(client, command);
 595                         if (status >= 0) {
 596                                 gsb->bdata = status;
 597                                 status = 0;
 598                         }
 599                 } else {
 600                         status = i2c_smbus_write_byte_data(client, command,
 601                                         gsb->bdata);
 602                 }
 603                 break;
 604
 605         case ACPI_GSB_ACCESS_ATTRIB_WORD:
 606                 if (action == ACPI_READ) {
 607                         status = i2c_smbus_read_word_data(client, command);
 608                         if (status >= 0) {
 609                                 gsb->wdata = status;
 610                                 status = 0;
 611                         }
 612                 } else {
 613                         status = i2c_smbus_write_word_data(client, command,
 614                                         gsb->wdata);
 615                 }
 616                 break;
 617
 618         case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
 619                 if (action == ACPI_READ) {
 620                         status = i2c_smbus_read_block_data(client, command,
 621                                         gsb->data);
 622                         if (status >= 0) {
 623                                 gsb->len = status;
 624                                 status = 0;
 625                         }
 626                 } else {
 627                         status = i2c_smbus_write_block_data(client, command,
 628                                         gsb->len, gsb->data);
 629                 }
 630                 break;
 631
 632         case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
 633                 if (action == ACPI_READ) {
 634                         status = acpi_gsb_i2c_read_bytes(client, command,
 635                                         gsb->data, info->access_length);
 636                 } else {
 637                         status = acpi_gsb_i2c_write_bytes(client, command,
 638                                         gsb->data, info->access_length);
 639                 }
 640                 break;
 641
 642         default:
 643                 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
 644                          accessor_type, client->addr);
 645                 ret = AE_BAD_PARAMETER;
 646                 goto err;
 647         }
 648
 649         gsb->status = status;
 650
 651  err:
 652         kfree(client);
 653         ACPI_FREE(ares);
 654         return ret;
 655 }
 656
 657
 658 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
 659 {
 660         acpi_handle handle;
 661         struct i2c_acpi_handler_data *data;
 662         acpi_status status;
 663
 664         if (!adapter->dev.parent)
 665                 return -ENODEV;
 666
 667         handle = ACPI_HANDLE(adapter->dev.parent);
 668
 669         if (!handle)
 670                 return -ENODEV;
 671
 672         data = kzalloc(sizeof(struct i2c_acpi_handler_data),
 673                             GFP_KERNEL);
 674         if (!data)
 675                 return -ENOMEM;
 676
 677         data->adapter = adapter;
 678         status = acpi_bus_attach_private_data(handle, (void *)data);
 679         if (ACPI_FAILURE(status)) {
 680                 kfree(data);
 681                 return -ENOMEM;
 682         }
 683
 684         status = acpi_install_address_space_handler(handle,
 685                                 ACPI_ADR_SPACE_GSBUS,
 686                                 &i2c_acpi_space_handler,
 687                                 NULL,
 688                                 data);
 689         if (ACPI_FAILURE(status)) {
 690                 dev_err(&adapter->dev, "Error installing i2c space handler\n");
 691                 acpi_bus_detach_private_data(handle);
 692                 kfree(data);
 693                 return -ENOMEM;
 694         }
 695
 696         acpi_walk_dep_device_list(handle);
 697         return 0;
 698 }
 699
 700 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
 701 {
 702         acpi_handle handle;
 703         struct i2c_acpi_handler_data *data;
 704         acpi_status status;
 705
 706         if (!adapter->dev.parent)
 707                 return;
 708
 709         handle = ACPI_HANDLE(adapter->dev.parent);
 710
 711         if (!handle)
 712                 return;
 713
 714         acpi_remove_address_space_handler(handle,
 715                                 ACPI_ADR_SPACE_GSBUS,
 716                                 &i2c_acpi_space_handler);
 717
 718         status = acpi_bus_get_private_data(handle, (void **)&data);
 719         if (ACPI_SUCCESS(status))
 720                 kfree(data);
 721
 722         acpi_bus_detach_private_data(handle);
 723 }
 724 #endif /* CONFIG_ACPI_I2C_OPREGION */