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 <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 static int i2c_acpi_find_match_adapter(struct device *dev, const void *data)
 402 {
 403         struct i2c_adapter *adapter = i2c_verify_adapter(dev);
 404
 405         if (!adapter)
 406                 return 0;
 407
 408         return ACPI_HANDLE(dev) == (acpi_handle)data;
 409 }
 410
 411 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 412 {
 413         struct device *dev;
 414
 415         dev = bus_find_device(&i2c_bus_type, NULL, handle,
 416                               i2c_acpi_find_match_adapter);
 417
 418         return dev ? i2c_verify_adapter(dev) : NULL;
 419 }
 420 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 421
 422 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 423 {
 424         struct device *dev;
 425         struct i2c_client *client;
 426
 427         dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
 428         if (!dev)
 429                 return NULL;
 430
 431         client = i2c_verify_client(dev);
 432         if (!client)
 433                 put_device(dev);
 434
 435         return client;
 436 }
 437
 438 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
 439                            void *arg)
 440 {
 441         struct acpi_device *adev = arg;
 442         struct i2c_board_info info;
 443         acpi_handle adapter_handle;
 444         struct i2c_adapter *adapter;
 445         struct i2c_client *client;
 446
 447         switch (value) {
 448         case ACPI_RECONFIG_DEVICE_ADD:
 449                 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
 450                         break;
 451
 452                 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
 453                 if (!adapter)
 454                         break;
 455
 456                 i2c_acpi_register_device(adapter, adev, &info);
 457                 break;
 458         case ACPI_RECONFIG_DEVICE_REMOVE:
 459                 if (!acpi_device_enumerated(adev))
 460                         break;
 461
 462                 client = i2c_acpi_find_client_by_adev(adev);
 463                 if (!client)
 464                         break;
 465
 466                 i2c_unregister_device(client);
 467                 put_device(&client->dev);
 468                 break;
 469         }
 470
 471         return NOTIFY_OK;
 472 }
 473
 474 struct notifier_block i2c_acpi_notifier = {
 475         .notifier_call = i2c_acpi_notify,
 476 };
 477
 478 /**
 479  * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
 480  * @dev:     Device owning the ACPI resources to get the client from
 481  * @index:   Index of ACPI resource to get
 482  * @info:    describes the I2C device; note this is modified (addr gets set)
 483  * Context: can sleep
 484  *
 485  * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
 486  * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
 487  * resources, in that case this function can be used to create an i2c-client
 488  * for other I2cSerialBus resources in the Current Resource Settings table.
 489  *
 490  * Also see i2c_new_client_device, which this function calls to create the
 491  * i2c-client.
 492  *
 493  * Returns a pointer to the new i2c-client, or error pointer in case of failure.
 494  * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
 495  */
 496 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
 497                                        struct i2c_board_info *info)
 498 {
 499         struct acpi_device *adev = ACPI_COMPANION(dev);
 500         struct i2c_acpi_lookup lookup;
 501         struct i2c_adapter *adapter;
 502         LIST_HEAD(resource_list);
 503         int ret;
 504
 505         memset(&lookup, 0, sizeof(lookup));
 506         lookup.info = info;
 507         lookup.device_handle = acpi_device_handle(adev);
 508         lookup.index = index;
 509
 510         ret = acpi_dev_get_resources(adev, &resource_list,
 511                                      i2c_acpi_fill_info, &lookup);
 512         if (ret < 0)
 513                 return ERR_PTR(ret);
 514
 515         acpi_dev_free_resource_list(&resource_list);
 516
 517         if (!info->addr)
 518                 return ERR_PTR(-EADDRNOTAVAIL);
 519
 520         adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
 521         if (!adapter)
 522                 return ERR_PTR(-EPROBE_DEFER);
 523
 524         return i2c_new_client_device(adapter, info);
 525 }
 526 EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
 527
 528 #ifdef CONFIG_ACPI_I2C_OPREGION
 529 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
 530                 u8 cmd, u8 *data, u8 data_len)
 531 {
 532
 533         struct i2c_msg msgs[2];
 534         int ret;
 535         u8 *buffer;
 536
 537         buffer = kzalloc(data_len, GFP_KERNEL);
 538         if (!buffer)
 539                 return AE_NO_MEMORY;
 540
 541         msgs[0].addr = client->addr;
 542         msgs[0].flags = client->flags;
 543         msgs[0].len = 1;
 544         msgs[0].buf = &cmd;
 545
 546         msgs[1].addr = client->addr;
 547         msgs[1].flags = client->flags | I2C_M_RD;
 548         msgs[1].len = data_len;
 549         msgs[1].buf = buffer;
 550
 551         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 552         if (ret < 0) {
 553                 /* Getting a NACK is unfortunately normal with some DSTDs */
 554                 if (ret == -EREMOTEIO)
 555                         dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 556                                 data_len, client->addr, cmd, ret);
 557                 else
 558                         dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 559                                 data_len, client->addr, cmd, ret);
 560         /* 2 transfers must have completed successfully */
 561         } else if (ret == 2) {
 562                 memcpy(data, buffer, data_len);
 563                 ret = 0;
 564         } else {
 565                 ret = -EIO;
 566         }
 567
 568         kfree(buffer);
 569         return ret;
 570 }
 571
 572 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
 573                 u8 cmd, u8 *data, u8 data_len)
 574 {
 575
 576         struct i2c_msg msgs[1];
 577         u8 *buffer;
 578         int ret = AE_OK;
 579
 580         buffer = kzalloc(data_len + 1, GFP_KERNEL);
 581         if (!buffer)
 582                 return AE_NO_MEMORY;
 583
 584         buffer[0] = cmd;
 585         memcpy(buffer + 1, data, data_len);
 586
 587         msgs[0].addr = client->addr;
 588         msgs[0].flags = client->flags;
 589         msgs[0].len = data_len + 1;
 590         msgs[0].buf = buffer;
 591
 592         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 593
 594         kfree(buffer);
 595
 596         if (ret < 0) {
 597                 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
 598                 return ret;
 599         }
 600
 601         /* 1 transfer must have completed successfully */
 602         return (ret == 1) ? 0 : -EIO;
 603 }
 604
 605 static acpi_status
 606 i2c_acpi_space_handler(u32 function, acpi_physical_address command,
 607                         u32 bits, u64 *value64,
 608                         void *handler_context, void *region_context)
 609 {
 610         struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
 611         struct i2c_acpi_handler_data *data = handler_context;
 612         struct acpi_connection_info *info = &data->info;
 613         struct acpi_resource_i2c_serialbus *sb;
 614         struct i2c_adapter *adapter = data->adapter;
 615         struct i2c_client *client;
 616         struct acpi_resource *ares;
 617         u32 accessor_type = function >> 16;
 618         u8 action = function & ACPI_IO_MASK;
 619         acpi_status ret;
 620         int status;
 621
 622         ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
 623         if (ACPI_FAILURE(ret))
 624                 return ret;
 625
 626         client = kzalloc(sizeof(*client), GFP_KERNEL);
 627         if (!client) {
 628                 ret = AE_NO_MEMORY;
 629                 goto err;
 630         }
 631
 632         if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
 633                 ret = AE_BAD_PARAMETER;
 634                 goto err;
 635         }
 636
 637         client->adapter = adapter;
 638         client->addr = sb->slave_address;
 639
 640         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
 641                 client->flags |= I2C_CLIENT_TEN;
 642
 643         switch (accessor_type) {
 644         case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
 645                 if (action == ACPI_READ) {
 646                         status = i2c_smbus_read_byte(client);
 647                         if (status >= 0) {
 648                                 gsb->bdata = status;
 649                                 status = 0;
 650                         }
 651                 } else {
 652                         status = i2c_smbus_write_byte(client, gsb->bdata);
 653                 }
 654                 break;
 655
 656         case ACPI_GSB_ACCESS_ATTRIB_BYTE:
 657                 if (action == ACPI_READ) {
 658                         status = i2c_smbus_read_byte_data(client, command);
 659                         if (status >= 0) {
 660                                 gsb->bdata = status;
 661                                 status = 0;
 662                         }
 663                 } else {
 664                         status = i2c_smbus_write_byte_data(client, command,
 665                                         gsb->bdata);
 666                 }
 667                 break;
 668
 669         case ACPI_GSB_ACCESS_ATTRIB_WORD:
 670                 if (action == ACPI_READ) {
 671                         status = i2c_smbus_read_word_data(client, command);
 672                         if (status >= 0) {
 673                                 gsb->wdata = status;
 674                                 status = 0;
 675                         }
 676                 } else {
 677                         status = i2c_smbus_write_word_data(client, command,
 678                                         gsb->wdata);
 679                 }
 680                 break;
 681
 682         case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
 683                 if (action == ACPI_READ) {
 684                         status = i2c_smbus_read_block_data(client, command,
 685                                         gsb->data);
 686                         if (status >= 0) {
 687                                 gsb->len = status;
 688                                 status = 0;
 689                         }
 690                 } else {
 691                         status = i2c_smbus_write_block_data(client, command,
 692                                         gsb->len, gsb->data);
 693                 }
 694                 break;
 695
 696         case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
 697                 if (action == ACPI_READ) {
 698                         status = acpi_gsb_i2c_read_bytes(client, command,
 699                                         gsb->data, info->access_length);
 700                 } else {
 701                         status = acpi_gsb_i2c_write_bytes(client, command,
 702                                         gsb->data, info->access_length);
 703                 }
 704                 break;
 705
 706         default:
 707                 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
 708                          accessor_type, client->addr);
 709                 ret = AE_BAD_PARAMETER;
 710                 goto err;
 711         }
 712
 713         gsb->status = status;
 714
 715  err:
 716         kfree(client);
 717         ACPI_FREE(ares);
 718         return ret;
 719 }
 720
 721
 722 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
 723 {
 724         acpi_handle handle;
 725         struct i2c_acpi_handler_data *data;
 726         acpi_status status;
 727
 728         if (!adapter->dev.parent)
 729                 return -ENODEV;
 730
 731         handle = ACPI_HANDLE(adapter->dev.parent);
 732
 733         if (!handle)
 734                 return -ENODEV;
 735
 736         data = kzalloc(sizeof(struct i2c_acpi_handler_data),
 737                             GFP_KERNEL);
 738         if (!data)
 739                 return -ENOMEM;
 740
 741         data->adapter = adapter;
 742         status = acpi_bus_attach_private_data(handle, (void *)data);
 743         if (ACPI_FAILURE(status)) {
 744                 kfree(data);
 745                 return -ENOMEM;
 746         }
 747
 748         status = acpi_install_address_space_handler(handle,
 749                                 ACPI_ADR_SPACE_GSBUS,
 750                                 &i2c_acpi_space_handler,
 751                                 NULL,
 752                                 data);
 753         if (ACPI_FAILURE(status)) {
 754                 dev_err(&adapter->dev, "Error installing i2c space handler\n");
 755                 acpi_bus_detach_private_data(handle);
 756                 kfree(data);
 757                 return -ENOMEM;
 758         }
 759
 760         return 0;
 761 }
 762
 763 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
 764 {
 765         acpi_handle handle;
 766         struct i2c_acpi_handler_data *data;
 767         acpi_status status;
 768
 769         if (!adapter->dev.parent)
 770                 return;
 771
 772         handle = ACPI_HANDLE(adapter->dev.parent);
 773
 774         if (!handle)
 775                 return;
 776
 777         acpi_remove_address_space_handler(handle,
 778                                 ACPI_ADR_SPACE_GSBUS,
 779                                 &i2c_acpi_space_handler);
 780
 781         status = acpi_bus_get_private_data(handle, (void **)&data);
 782         if (ACPI_SUCCESS(status))
 783                 kfree(data);
 784
 785         acpi_bus_detach_private_data(handle);
 786 }
 787 #endif /* CONFIG_ACPI_I2C_OPREGION */