drivers/i2c/i2c-core-acpi.c

   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 <[email protected]>
   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))
 148                 return -EINVAL;
 149
 150         if (!acpi_dev_ready_for_enumeration(adev))
 151                 return -ENODEV;
 152
 153         if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)
 154                 return -ENODEV;
 155
 156         memset(info, 0, sizeof(*info));
 157         lookup->device_handle = acpi_device_handle(adev);
 158
 159         /* Look up for I2cSerialBus resource */
 160         INIT_LIST_HEAD(&resource_list);
 161         ret = acpi_dev_get_resources(adev, &resource_list,
 162                                      i2c_acpi_fill_info, lookup);
 163         acpi_dev_free_resource_list(&resource_list);
 164
 165         if (ret < 0 || !info->addr)
 166                 return -EINVAL;
 167
 168         return 0;
 169 }
 170
 171 static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
 172 {
 173         int *irq = data;
 174         struct resource r;
 175
 176         if (*irq <= 0 && acpi_dev_resource_interrupt(ares, 0, &r))
 177                 *irq = i2c_dev_irq_from_resources(&r, 1);
 178
 179         return 1; /* No need to add resource to the list */
 180 }
 181
 182 /**
 183  * i2c_acpi_get_irq - get device IRQ number from ACPI
 184  * @client: Pointer to the I2C client device
 185  *
 186  * Find the IRQ number used by a specific client device.
 187  *
 188  * Return: The IRQ number or an error code.
 189  */
 190 int i2c_acpi_get_irq(struct i2c_client *client)
 191 {
 192         struct acpi_device *adev = ACPI_COMPANION(&client->dev);
 193         struct list_head resource_list;
 194         int irq = -ENOENT;
 195         int ret;
 196
 197         INIT_LIST_HEAD(&resource_list);
 198
 199         ret = acpi_dev_get_resources(adev, &resource_list,
 200                                      i2c_acpi_add_resource, &irq);
 201         if (ret < 0)
 202                 return ret;
 203
 204         acpi_dev_free_resource_list(&resource_list);
 205
 206         if (irq == -ENOENT)
 207                 irq = acpi_dev_gpio_irq_get(adev, 0);
 208
 209         return irq;
 210 }
 211
 212 static int i2c_acpi_get_info(struct acpi_device *adev,
 213                              struct i2c_board_info *info,
 214                              struct i2c_adapter *adapter,
 215                              acpi_handle *adapter_handle)
 216 {
 217         struct i2c_acpi_lookup lookup;
 218         int ret;
 219
 220         memset(&lookup, 0, sizeof(lookup));
 221         lookup.info = info;
 222         lookup.index = -1;
 223
 224         if (acpi_device_enumerated(adev))
 225                 return -EINVAL;
 226
 227         ret = i2c_acpi_do_lookup(adev, &lookup);
 228         if (ret)
 229                 return ret;
 230
 231         if (adapter) {
 232                 /* The adapter must match the one in I2cSerialBus() connector */
 233                 if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
 234                         return -ENODEV;
 235         } else {
 236                 struct acpi_device *adapter_adev;
 237
 238                 /* The adapter must be present */
 239                 adapter_adev = acpi_fetch_acpi_dev(lookup.adapter_handle);
 240                 if (!adapter_adev)
 241                         return -ENODEV;
 242                 if (acpi_bus_get_status(adapter_adev) ||
 243                     !adapter_adev->status.present)
 244                         return -ENODEV;
 245         }
 246
 247         info->fwnode = acpi_fwnode_handle(adev);
 248         if (adapter_handle)
 249                 *adapter_handle = lookup.adapter_handle;
 250
 251         acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
 252                           sizeof(info->type));
 253
 254         return 0;
 255 }
 256
 257 static void i2c_acpi_register_device(struct i2c_adapter *adapter,
 258                                      struct acpi_device *adev,
 259                                      struct i2c_board_info *info)
 260 {
 261         /*
 262          * Skip registration on boards where the ACPI tables are
 263          * known to contain bogus I2C devices.
 264          */
 265         if (acpi_quirk_skip_i2c_client_enumeration(adev))
 266                 return;
 267
 268         adev->power.flags.ignore_parent = true;
 269         acpi_device_set_enumerated(adev);
 270
 271         if (IS_ERR(i2c_new_client_device(adapter, info)))
 272                 adev->power.flags.ignore_parent = false;
 273 }
 274
 275 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
 276                                        void *data, void **return_value)
 277 {
 278         struct i2c_adapter *adapter = data;
 279         struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 280         struct i2c_board_info info;
 281
 282         if (!adev || i2c_acpi_get_info(adev, &info, adapter, NULL))
 283                 return AE_OK;
 284
 285         i2c_acpi_register_device(adapter, adev, &info);
 286
 287         return AE_OK;
 288 }
 289
 290 #define I2C_ACPI_MAX_SCAN_DEPTH 32
 291
 292 /**
 293  * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
 294  * @adap: pointer to adapter
 295  *
 296  * Enumerate all I2C slave devices behind this adapter by walking the ACPI
 297  * namespace. When a device is found it will be added to the Linux device
 298  * model and bound to the corresponding ACPI handle.
 299  */
 300 void i2c_acpi_register_devices(struct i2c_adapter *adap)
 301 {
 302         struct acpi_device *adev;
 303         acpi_status status;
 304
 305         if (!has_acpi_companion(&adap->dev))
 306                 return;
 307
 308         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 309                                      I2C_ACPI_MAX_SCAN_DEPTH,
 310                                      i2c_acpi_add_device, NULL,
 311                                      adap, NULL);
 312         if (ACPI_FAILURE(status))
 313                 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
 314
 315         if (!adap->dev.parent)
 316                 return;
 317
 318         adev = ACPI_COMPANION(adap->dev.parent);
 319         if (!adev)
 320                 return;
 321
 322         acpi_dev_clear_dependencies(adev);
 323 }
 324
 325 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
 326         /*
 327          * These Silead touchscreen controllers only work at 400KHz, for
 328          * some reason they do not work at 100KHz. On some devices the ACPI
 329          * tables list another device at their bus as only being capable
 330          * of 100KHz, testing has shown that these other devices work fine
 331          * at 400KHz (as can be expected of any recent i2c hw) so we force
 332          * the speed of the bus to 400 KHz if a Silead device is present.
 333          */
 334         { "MSSL1680", 0 },
 335         {}
 336 };
 337
 338 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
 339                                            void *data, void **return_value)
 340 {
 341         struct i2c_acpi_lookup *lookup = data;
 342         struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 343
 344         if (!adev || i2c_acpi_do_lookup(adev, lookup))
 345                 return AE_OK;
 346
 347         if (lookup->search_handle != lookup->adapter_handle)
 348                 return AE_OK;
 349
 350         if (lookup->speed <= lookup->min_speed)
 351                 lookup->min_speed = lookup->speed;
 352
 353         if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
 354                 lookup->force_speed = I2C_MAX_FAST_MODE_FREQ;
 355
 356         return AE_OK;
 357 }
 358
 359 /**
 360  * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
 361  * @dev: The device owning the bus
 362  *
 363  * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
 364  * devices connected to this bus and use the speed of slowest device.
 365  *
 366  * Returns the speed in Hz or zero
 367  */
 368 u32 i2c_acpi_find_bus_speed(struct device *dev)
 369 {
 370         struct i2c_acpi_lookup lookup;
 371         struct i2c_board_info dummy;
 372         acpi_status status;
 373
 374         if (!has_acpi_companion(dev))
 375                 return 0;
 376
 377         memset(&lookup, 0, sizeof(lookup));
 378         lookup.search_handle = ACPI_HANDLE(dev);
 379         lookup.min_speed = UINT_MAX;
 380         lookup.info = &dummy;
 381         lookup.index = -1;
 382
 383         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 384                                      I2C_ACPI_MAX_SCAN_DEPTH,
 385                                      i2c_acpi_lookup_speed, NULL,
 386                                      &lookup, NULL);
 387
 388         if (ACPI_FAILURE(status)) {
 389                 dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
 390                 return 0;
 391         }
 392
 393         if (lookup.force_speed) {
 394                 if (lookup.force_speed != lookup.min_speed)
 395                         dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
 396                                  lookup.min_speed, lookup.force_speed);
 397                 return lookup.force_speed;
 398         } else if (lookup.min_speed != UINT_MAX) {
 399                 return lookup.min_speed;
 400         } else {
 401                 return 0;
 402         }
 403 }
 404 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
 405
 406 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 407 {
 408         struct i2c_adapter *adapter;
 409         struct device *dev;
 410
 411         dev = bus_find_device(&i2c_bus_type, NULL, handle, device_match_acpi_handle);
 412         if (!dev)
 413                 return NULL;
 414
 415         adapter = i2c_verify_adapter(dev);
 416         if (!adapter)
 417                 put_device(dev);
 418
 419         return adapter;
 420 }
 421 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 422
 423 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 424 {
 425         struct device *dev;
 426         struct i2c_client *client;
 427
 428         dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
 429         if (!dev)
 430                 return NULL;
 431
 432         client = i2c_verify_client(dev);
 433         if (!client)
 434                 put_device(dev);
 435
 436         return client;
 437 }
 438
 439 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
 440                            void *arg)
 441 {
 442         struct acpi_device *adev = arg;
 443         struct i2c_board_info info;
 444         acpi_handle adapter_handle;
 445         struct i2c_adapter *adapter;
 446         struct i2c_client *client;
 447
 448         switch (value) {
 449         case ACPI_RECONFIG_DEVICE_ADD:
 450                 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
 451                         break;
 452
 453                 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
 454                 if (!adapter)
 455                         break;
 456
 457                 i2c_acpi_register_device(adapter, adev, &info);
 458                 put_device(&adapter->dev);
 459                 break;
 460         case ACPI_RECONFIG_DEVICE_REMOVE:
 461                 if (!acpi_device_enumerated(adev))
 462                         break;
 463
 464                 client = i2c_acpi_find_client_by_adev(adev);
 465                 if (!client)
 466                         break;
 467
 468                 i2c_unregister_device(client);
 469                 put_device(&client->dev);
 470                 break;
 471         }
 472
 473         return NOTIFY_OK;
 474 }
 475
 476 struct notifier_block i2c_acpi_notifier = {
 477         .notifier_call = i2c_acpi_notify,
 478 };
 479
 480 /**
 481  * i2c_acpi_new_device_by_fwnode - Create i2c-client for the Nth I2cSerialBus resource
 482  * @fwnode:  fwnode with the ACPI resources to get the client from
 483  * @index:   Index of ACPI resource to get
 484  * @info:    describes the I2C device; note this is modified (addr gets set)
 485  * Context: can sleep
 486  *
 487  * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
 488  * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
 489  * resources, in that case this function can be used to create an i2c-client
 490  * for other I2cSerialBus resources in the Current Resource Settings table.
 491  *
 492  * Also see i2c_new_client_device, which this function calls to create the
 493  * i2c-client.
 494  *
 495  * Returns a pointer to the new i2c-client, or error pointer in case of failure.
 496  * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
 497  */
 498 struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
 499                                                  int index,
 500                                                  struct i2c_board_info *info)
 501 {
 502         struct i2c_acpi_lookup lookup;
 503         struct i2c_adapter *adapter;
 504         struct acpi_device *adev;
 505         LIST_HEAD(resource_list);
 506         int ret;
 507
 508         adev = to_acpi_device_node(fwnode);
 509         if (!adev)
 510                 return ERR_PTR(-ENODEV);
 511
 512         memset(&lookup, 0, sizeof(lookup));
 513         lookup.info = info;
 514         lookup.device_handle = acpi_device_handle(adev);
 515         lookup.index = index;
 516
 517         ret = acpi_dev_get_resources(adev, &resource_list,
 518                                      i2c_acpi_fill_info, &lookup);
 519         if (ret < 0)
 520                 return ERR_PTR(ret);
 521
 522         acpi_dev_free_resource_list(&resource_list);
 523
 524         if (!info->addr)
 525                 return ERR_PTR(-EADDRNOTAVAIL);
 526
 527         adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
 528         if (!adapter)
 529                 return ERR_PTR(-EPROBE_DEFER);
 530
 531         return i2c_new_client_device(adapter, info);
 532 }
 533 EXPORT_SYMBOL_GPL(i2c_acpi_new_device_by_fwnode);
 534
 535 bool i2c_acpi_waive_d0_probe(struct device *dev)
 536 {
 537         struct i2c_driver *driver = to_i2c_driver(dev->driver);
 538         struct acpi_device *adev = ACPI_COMPANION(dev);
 539
 540         return driver->flags & I2C_DRV_ACPI_WAIVE_D0_PROBE &&
 541                 adev && adev->power.state_for_enumeration >= adev->power.state;
 542 }
 543 EXPORT_SYMBOL_GPL(i2c_acpi_waive_d0_probe);
 544
 545 #ifdef CONFIG_ACPI_I2C_OPREGION
 546 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
 547                 u8 cmd, u8 *data, u8 data_len)
 548 {
 549
 550         struct i2c_msg msgs[2];
 551         int ret;
 552         u8 *buffer;
 553
 554         buffer = kzalloc(data_len, GFP_KERNEL);
 555         if (!buffer)
 556                 return AE_NO_MEMORY;
 557
 558         msgs[0].addr = client->addr;
 559         msgs[0].flags = client->flags;
 560         msgs[0].len = 1;
 561         msgs[0].buf = &cmd;
 562
 563         msgs[1].addr = client->addr;
 564         msgs[1].flags = client->flags | I2C_M_RD;
 565         msgs[1].len = data_len;
 566         msgs[1].buf = buffer;
 567
 568         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 569         if (ret < 0) {
 570                 /* Getting a NACK is unfortunately normal with some DSTDs */
 571                 if (ret == -EREMOTEIO)
 572                         dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 573                                 data_len, client->addr, cmd, ret);
 574                 else
 575                         dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 576                                 data_len, client->addr, cmd, ret);
 577         /* 2 transfers must have completed successfully */
 578         } else if (ret == 2) {
 579                 memcpy(data, buffer, data_len);
 580                 ret = 0;
 581         } else {
 582                 ret = -EIO;
 583         }
 584
 585         kfree(buffer);
 586         return ret;
 587 }
 588
 589 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
 590                 u8 cmd, u8 *data, u8 data_len)
 591 {
 592
 593         struct i2c_msg msgs[1];
 594         u8 *buffer;
 595         int ret = AE_OK;
 596
 597         buffer = kzalloc(data_len + 1, GFP_KERNEL);
 598         if (!buffer)
 599                 return AE_NO_MEMORY;
 600
 601         buffer[0] = cmd;
 602         memcpy(buffer + 1, data, data_len);
 603
 604         msgs[0].addr = client->addr;
 605         msgs[0].flags = client->flags;
 606         msgs[0].len = data_len + 1;
 607         msgs[0].buf = buffer;
 608
 609         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 610
 611         kfree(buffer);
 612
 613         if (ret < 0) {
 614                 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
 615                 return ret;
 616         }
 617
 618         /* 1 transfer must have completed successfully */
 619         return (ret == 1) ? 0 : -EIO;
 620 }
 621
 622 static acpi_status
 623 i2c_acpi_space_handler(u32 function, acpi_physical_address command,
 624                         u32 bits, u64 *value64,
 625                         void *handler_context, void *region_context)
 626 {
 627         struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
 628         struct i2c_acpi_handler_data *data = handler_context;
 629         struct acpi_connection_info *info = &data->info;
 630         struct acpi_resource_i2c_serialbus *sb;
 631         struct i2c_adapter *adapter = data->adapter;
 632         struct i2c_client *client;
 633         struct acpi_resource *ares;
 634         u32 accessor_type = function >> 16;
 635         u8 action = function & ACPI_IO_MASK;
 636         acpi_status ret;
 637         int status;
 638
 639         ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
 640         if (ACPI_FAILURE(ret))
 641                 return ret;
 642
 643         client = kzalloc(sizeof(*client), GFP_KERNEL);
 644         if (!client) {
 645                 ret = AE_NO_MEMORY;
 646                 goto err;
 647         }
 648
 649         if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
 650                 ret = AE_BAD_PARAMETER;
 651                 goto err;
 652         }
 653
 654         client->adapter = adapter;
 655         client->addr = sb->slave_address;
 656
 657         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
 658                 client->flags |= I2C_CLIENT_TEN;
 659
 660         switch (accessor_type) {
 661         case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
 662                 if (action == ACPI_READ) {
 663                         status = i2c_smbus_read_byte(client);
 664                         if (status >= 0) {
 665                                 gsb->bdata = status;
 666                                 status = 0;
 667                         }
 668                 } else {
 669                         status = i2c_smbus_write_byte(client, gsb->bdata);
 670                 }
 671                 break;
 672
 673         case ACPI_GSB_ACCESS_ATTRIB_BYTE:
 674                 if (action == ACPI_READ) {
 675                         status = i2c_smbus_read_byte_data(client, command);
 676                         if (status >= 0) {
 677                                 gsb->bdata = status;
 678                                 status = 0;
 679                         }
 680                 } else {
 681                         status = i2c_smbus_write_byte_data(client, command,
 682                                         gsb->bdata);
 683                 }
 684                 break;
 685
 686         case ACPI_GSB_ACCESS_ATTRIB_WORD:
 687                 if (action == ACPI_READ) {
 688                         status = i2c_smbus_read_word_data(client, command);
 689                         if (status >= 0) {
 690                                 gsb->wdata = status;
 691                                 status = 0;
 692                         }
 693                 } else {
 694                         status = i2c_smbus_write_word_data(client, command,
 695                                         gsb->wdata);
 696                 }
 697                 break;
 698
 699         case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
 700                 if (action == ACPI_READ) {
 701                         status = i2c_smbus_read_block_data(client, command,
 702                                         gsb->data);
 703                         if (status >= 0) {
 704                                 gsb->len = status;
 705                                 status = 0;
 706                         }
 707                 } else {
 708                         status = i2c_smbus_write_block_data(client, command,
 709                                         gsb->len, gsb->data);
 710                 }
 711                 break;
 712
 713         case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
 714                 if (action == ACPI_READ) {
 715                         status = acpi_gsb_i2c_read_bytes(client, command,
 716                                         gsb->data, info->access_length);
 717                 } else {
 718                         status = acpi_gsb_i2c_write_bytes(client, command,
 719                                         gsb->data, info->access_length);
 720                 }
 721                 break;
 722
 723         default:
 724                 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
 725                          accessor_type, client->addr);
 726                 ret = AE_BAD_PARAMETER;
 727                 goto err;
 728         }
 729
 730         gsb->status = status;
 731
 732  err:
 733         kfree(client);
 734         ACPI_FREE(ares);
 735         return ret;
 736 }
 737
 738
 739 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
 740 {
 741         acpi_handle handle;
 742         struct i2c_acpi_handler_data *data;
 743         acpi_status status;
 744
 745         if (!adapter->dev.parent)
 746                 return -ENODEV;
 747
 748         handle = ACPI_HANDLE(adapter->dev.parent);
 749
 750         if (!handle)
 751                 return -ENODEV;
 752
 753         data = kzalloc(sizeof(struct i2c_acpi_handler_data),
 754                             GFP_KERNEL);
 755         if (!data)
 756                 return -ENOMEM;
 757
 758         data->adapter = adapter;
 759         status = acpi_bus_attach_private_data(handle, (void *)data);
 760         if (ACPI_FAILURE(status)) {
 761                 kfree(data);
 762                 return -ENOMEM;
 763         }
 764
 765         status = acpi_install_address_space_handler(handle,
 766                                 ACPI_ADR_SPACE_GSBUS,
 767                                 &i2c_acpi_space_handler,
 768                                 NULL,
 769                                 data);
 770         if (ACPI_FAILURE(status)) {
 771                 dev_err(&adapter->dev, "Error installing i2c space handler\n");
 772                 acpi_bus_detach_private_data(handle);
 773                 kfree(data);
 774                 return -ENOMEM;
 775         }
 776
 777         return 0;
 778 }
 779
 780 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
 781 {
 782         acpi_handle handle;
 783         struct i2c_acpi_handler_data *data;
 784         acpi_status status;
 785
 786         if (!adapter->dev.parent)
 787                 return;
 788
 789         handle = ACPI_HANDLE(adapter->dev.parent);
 790
 791         if (!handle)
 792                 return;
 793
 794         acpi_remove_address_space_handler(handle,
 795                                 ACPI_ADR_SPACE_GSBUS,
 796                                 &i2c_acpi_space_handler);
 797
 798         status = acpi_bus_get_private_data(handle, (void **)&data);
 799         if (ACPI_SUCCESS(status))
 800                 kfree(data);
 801
 802         acpi_bus_detach_private_data(handle);
 803 }
 804 #endif /* CONFIG_ACPI_I2C_OPREGION */