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_fill_info(struct acpi_resource *ares, void *data)
  73 {
  74         struct i2c_acpi_lookup *lookup = data;
  75         struct i2c_board_info *info = lookup->info;
  76         struct acpi_resource_i2c_serialbus *sb;
  77         acpi_status status;
  78
  79         if (info->addr || !i2c_acpi_get_i2c_resource(ares, &sb))
  80                 return 1;
  81
  82         if (lookup->index != -1 && lookup->n++ != lookup->index)
  83                 return 1;
  84
  85         status = acpi_get_handle(lookup->device_handle,
  86                                  sb->resource_source.string_ptr,
  87                                  &lookup->adapter_handle);
  88         if (ACPI_FAILURE(status))
  89                 return 1;
  90
  91         info->addr = sb->slave_address;
  92         lookup->speed = sb->connection_speed;
  93         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
  94                 info->flags |= I2C_CLIENT_TEN;
  95
  96         return 1;
  97 }
  98
  99 static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
 100         /*
 101          * ACPI video acpi_devices, which are handled by the acpi-video driver
 102          * sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these.
 103          */
 104         { ACPI_VIDEO_HID, 0 },
 105         {}
 106 };
 107
 108 static int i2c_acpi_do_lookup(struct acpi_device *adev,
 109                               struct i2c_acpi_lookup *lookup)
 110 {
 111         struct i2c_board_info *info = lookup->info;
 112         struct list_head resource_list;
 113         int ret;
 114
 115         if (acpi_bus_get_status(adev) || !adev->status.present)
 116                 return -EINVAL;
 117
 118         if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)
 119                 return -ENODEV;
 120
 121         memset(info, 0, sizeof(*info));
 122         lookup->device_handle = acpi_device_handle(adev);
 123
 124         /* Look up for I2cSerialBus resource */
 125         INIT_LIST_HEAD(&resource_list);
 126         ret = acpi_dev_get_resources(adev, &resource_list,
 127                                      i2c_acpi_fill_info, lookup);
 128         acpi_dev_free_resource_list(&resource_list);
 129
 130         if (ret < 0 || !info->addr)
 131                 return -EINVAL;
 132
 133         return 0;
 134 }
 135
 136 static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
 137 {
 138         int *irq = data;
 139         struct resource r;
 140
 141         if (*irq <= 0 && acpi_dev_resource_interrupt(ares, 0, &r))
 142                 *irq = i2c_dev_irq_from_resources(&r, 1);
 143
 144         return 1; /* No need to add resource to the list */
 145 }
 146
 147 /**
 148  * i2c_acpi_get_irq - get device IRQ number from ACPI
 149  * @client: Pointer to the I2C client device
 150  *
 151  * Find the IRQ number used by a specific client device.
 152  *
 153  * Return: The IRQ number or an error code.
 154  */
 155 int i2c_acpi_get_irq(struct i2c_client *client)
 156 {
 157         struct acpi_device *adev = ACPI_COMPANION(&client->dev);
 158         struct list_head resource_list;
 159         int irq = -ENOENT;
 160         int ret;
 161
 162         INIT_LIST_HEAD(&resource_list);
 163
 164         ret = acpi_dev_get_resources(adev, &resource_list,
 165                                      i2c_acpi_add_resource, &irq);
 166         if (ret < 0)
 167                 return ret;
 168
 169         acpi_dev_free_resource_list(&resource_list);
 170
 171         if (irq == -ENOENT)
 172                 irq = acpi_dev_gpio_irq_get(adev, 0);
 173
 174         return irq;
 175 }
 176
 177 static int i2c_acpi_get_info(struct acpi_device *adev,
 178                              struct i2c_board_info *info,
 179                              struct i2c_adapter *adapter,
 180                              acpi_handle *adapter_handle)
 181 {
 182         struct i2c_acpi_lookup lookup;
 183         int ret;
 184
 185         memset(&lookup, 0, sizeof(lookup));
 186         lookup.info = info;
 187         lookup.index = -1;
 188
 189         if (acpi_device_enumerated(adev))
 190                 return -EINVAL;
 191
 192         ret = i2c_acpi_do_lookup(adev, &lookup);
 193         if (ret)
 194                 return ret;
 195
 196         if (adapter) {
 197                 /* The adapter must match the one in I2cSerialBus() connector */
 198                 if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
 199                         return -ENODEV;
 200         } else {
 201                 struct acpi_device *adapter_adev;
 202
 203                 /* The adapter must be present */
 204                 if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
 205                         return -ENODEV;
 206                 if (acpi_bus_get_status(adapter_adev) ||
 207                     !adapter_adev->status.present)
 208                         return -ENODEV;
 209         }
 210
 211         info->fwnode = acpi_fwnode_handle(adev);
 212         if (adapter_handle)
 213                 *adapter_handle = lookup.adapter_handle;
 214
 215         acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
 216                           sizeof(info->type));
 217
 218         return 0;
 219 }
 220
 221 static void i2c_acpi_register_device(struct i2c_adapter *adapter,
 222                                      struct acpi_device *adev,
 223                                      struct i2c_board_info *info)
 224 {
 225         adev->power.flags.ignore_parent = true;
 226         acpi_device_set_enumerated(adev);
 227
 228         if (!i2c_new_device(adapter, info)) {
 229                 adev->power.flags.ignore_parent = false;
 230                 dev_err(&adapter->dev,
 231                         "failed to add I2C device %s from ACPI\n",
 232                         dev_name(&adev->dev));
 233         }
 234 }
 235
 236 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
 237                                        void *data, void **return_value)
 238 {
 239         struct i2c_adapter *adapter = data;
 240         struct acpi_device *adev;
 241         struct i2c_board_info info;
 242
 243         if (acpi_bus_get_device(handle, &adev))
 244                 return AE_OK;
 245
 246         if (i2c_acpi_get_info(adev, &info, adapter, NULL))
 247                 return AE_OK;
 248
 249         i2c_acpi_register_device(adapter, adev, &info);
 250
 251         return AE_OK;
 252 }
 253
 254 #define I2C_ACPI_MAX_SCAN_DEPTH 32
 255
 256 /**
 257  * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
 258  * @adap: pointer to adapter
 259  *
 260  * Enumerate all I2C slave devices behind this adapter by walking the ACPI
 261  * namespace. When a device is found it will be added to the Linux device
 262  * model and bound to the corresponding ACPI handle.
 263  */
 264 void i2c_acpi_register_devices(struct i2c_adapter *adap)
 265 {
 266         acpi_status status;
 267
 268         if (!has_acpi_companion(&adap->dev))
 269                 return;
 270
 271         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 272                                      I2C_ACPI_MAX_SCAN_DEPTH,
 273                                      i2c_acpi_add_device, NULL,
 274                                      adap, NULL);
 275         if (ACPI_FAILURE(status))
 276                 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
 277 }
 278
 279 const struct acpi_device_id *
 280 i2c_acpi_match_device(const struct acpi_device_id *matches,
 281                       struct i2c_client *client)
 282 {
 283         if (!(client && matches))
 284                 return NULL;
 285
 286         return acpi_match_device(matches, &client->dev);
 287 }
 288
 289 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
 290         /*
 291          * These Silead touchscreen controllers only work at 400KHz, for
 292          * some reason they do not work at 100KHz. On some devices the ACPI
 293          * tables list another device at their bus as only being capable
 294          * of 100KHz, testing has shown that these other devices work fine
 295          * at 400KHz (as can be expected of any recent i2c hw) so we force
 296          * the speed of the bus to 400 KHz if a Silead device is present.
 297          */
 298         { "MSSL1680", 0 },
 299         {}
 300 };
 301
 302 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
 303                                            void *data, void **return_value)
 304 {
 305         struct i2c_acpi_lookup *lookup = data;
 306         struct acpi_device *adev;
 307
 308         if (acpi_bus_get_device(handle, &adev))
 309                 return AE_OK;
 310
 311         if (i2c_acpi_do_lookup(adev, lookup))
 312                 return AE_OK;
 313
 314         if (lookup->search_handle != lookup->adapter_handle)
 315                 return AE_OK;
 316
 317         if (lookup->speed <= lookup->min_speed)
 318                 lookup->min_speed = lookup->speed;
 319
 320         if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
 321                 lookup->force_speed = 400000;
 322
 323         return AE_OK;
 324 }
 325
 326 /**
 327  * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
 328  * @dev: The device owning the bus
 329  *
 330  * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
 331  * devices connected to this bus and use the speed of slowest device.
 332  *
 333  * Returns the speed in Hz or zero
 334  */
 335 u32 i2c_acpi_find_bus_speed(struct device *dev)
 336 {
 337         struct i2c_acpi_lookup lookup;
 338         struct i2c_board_info dummy;
 339         acpi_status status;
 340
 341         if (!has_acpi_companion(dev))
 342                 return 0;
 343
 344         memset(&lookup, 0, sizeof(lookup));
 345         lookup.search_handle = ACPI_HANDLE(dev);
 346         lookup.min_speed = UINT_MAX;
 347         lookup.info = &dummy;
 348         lookup.index = -1;
 349
 350         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 351                                      I2C_ACPI_MAX_SCAN_DEPTH,
 352                                      i2c_acpi_lookup_speed, NULL,
 353                                      &lookup, NULL);
 354
 355         if (ACPI_FAILURE(status)) {
 356                 dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
 357                 return 0;
 358         }
 359
 360         if (lookup.force_speed) {
 361                 if (lookup.force_speed != lookup.min_speed)
 362                         dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
 363                                  lookup.min_speed, lookup.force_speed);
 364                 return lookup.force_speed;
 365         } else if (lookup.min_speed != UINT_MAX) {
 366                 return lookup.min_speed;
 367         } else {
 368                 return 0;
 369         }
 370 }
 371 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
 372
 373 static int i2c_acpi_find_match_adapter(struct device *dev, const void *data)
 374 {
 375         struct i2c_adapter *adapter = i2c_verify_adapter(dev);
 376
 377         if (!adapter)
 378                 return 0;
 379
 380         return ACPI_HANDLE(dev) == (acpi_handle)data;
 381 }
 382
 383 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 384 {
 385         struct device *dev;
 386
 387         dev = bus_find_device(&i2c_bus_type, NULL, handle,
 388                               i2c_acpi_find_match_adapter);
 389
 390         return dev ? i2c_verify_adapter(dev) : NULL;
 391 }
 392 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 393
 394 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 395 {
 396         struct device *dev;
 397
 398         dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
 399         return dev ? i2c_verify_client(dev) : NULL;
 400 }
 401
 402 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
 403                            void *arg)
 404 {
 405         struct acpi_device *adev = arg;
 406         struct i2c_board_info info;
 407         acpi_handle adapter_handle;
 408         struct i2c_adapter *adapter;
 409         struct i2c_client *client;
 410
 411         switch (value) {
 412         case ACPI_RECONFIG_DEVICE_ADD:
 413                 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
 414                         break;
 415
 416                 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
 417                 if (!adapter)
 418                         break;
 419
 420                 i2c_acpi_register_device(adapter, adev, &info);
 421                 break;
 422         case ACPI_RECONFIG_DEVICE_REMOVE:
 423                 if (!acpi_device_enumerated(adev))
 424                         break;
 425
 426                 client = i2c_acpi_find_client_by_adev(adev);
 427                 if (!client)
 428                         break;
 429
 430                 i2c_unregister_device(client);
 431                 put_device(&client->dev);
 432                 break;
 433         }
 434
 435         return NOTIFY_OK;
 436 }
 437
 438 struct notifier_block i2c_acpi_notifier = {
 439         .notifier_call = i2c_acpi_notify,
 440 };
 441
 442 /**
 443  * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
 444  * @dev:     Device owning the ACPI resources to get the client from
 445  * @index:   Index of ACPI resource to get
 446  * @info:    describes the I2C device; note this is modified (addr gets set)
 447  * Context: can sleep
 448  *
 449  * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
 450  * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
 451  * resources, in that case this function can be used to create an i2c-client
 452  * for other I2cSerialBus resources in the Current Resource Settings table.
 453  *
 454  * Also see i2c_new_device, which this function calls to create the i2c-client.
 455  *
 456  * Returns a pointer to the new i2c-client, or error pointer in case of failure.
 457  * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
 458  */
 459 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
 460                                        struct i2c_board_info *info)
 461 {
 462         struct i2c_acpi_lookup lookup;
 463         struct i2c_adapter *adapter;
 464         struct i2c_client *client;
 465         struct acpi_device *adev;
 466         LIST_HEAD(resource_list);
 467         int ret;
 468
 469         adev = ACPI_COMPANION(dev);
 470         if (!adev)
 471                 return ERR_PTR(-EINVAL);
 472
 473         memset(&lookup, 0, sizeof(lookup));
 474         lookup.info = info;
 475         lookup.device_handle = acpi_device_handle(adev);
 476         lookup.index = index;
 477
 478         ret = acpi_dev_get_resources(adev, &resource_list,
 479                                      i2c_acpi_fill_info, &lookup);
 480         if (ret < 0)
 481                 return ERR_PTR(ret);
 482
 483         acpi_dev_free_resource_list(&resource_list);
 484
 485         if (!info->addr)
 486                 return ERR_PTR(-EADDRNOTAVAIL);
 487
 488         adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
 489         if (!adapter)
 490                 return ERR_PTR(-EPROBE_DEFER);
 491
 492         client = i2c_new_device(adapter, info);
 493         if (!client)
 494                 return ERR_PTR(-ENODEV);
 495
 496         return client;
 497 }
 498 EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
 499
 500 #ifdef CONFIG_ACPI_I2C_OPREGION
 501 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
 502                 u8 cmd, u8 *data, u8 data_len)
 503 {
 504
 505         struct i2c_msg msgs[2];
 506         int ret;
 507         u8 *buffer;
 508
 509         buffer = kzalloc(data_len, GFP_KERNEL);
 510         if (!buffer)
 511                 return AE_NO_MEMORY;
 512
 513         msgs[0].addr = client->addr;
 514         msgs[0].flags = client->flags;
 515         msgs[0].len = 1;
 516         msgs[0].buf = &cmd;
 517
 518         msgs[1].addr = client->addr;
 519         msgs[1].flags = client->flags | I2C_M_RD;
 520         msgs[1].len = data_len;
 521         msgs[1].buf = buffer;
 522
 523         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 524         if (ret < 0) {
 525                 /* Getting a NACK is unfortunately normal with some DSTDs */
 526                 if (ret == -EREMOTEIO)
 527                         dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 528                                 data_len, client->addr, cmd, ret);
 529                 else
 530                         dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 531                                 data_len, client->addr, cmd, ret);
 532         /* 2 transfers must have completed successfully */
 533         } else if (ret == 2) {
 534                 memcpy(data, buffer, data_len);
 535                 ret = 0;
 536         } else {
 537                 ret = -EIO;
 538         }
 539
 540         kfree(buffer);
 541         return ret;
 542 }
 543
 544 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
 545                 u8 cmd, u8 *data, u8 data_len)
 546 {
 547
 548         struct i2c_msg msgs[1];
 549         u8 *buffer;
 550         int ret = AE_OK;
 551
 552         buffer = kzalloc(data_len + 1, GFP_KERNEL);
 553         if (!buffer)
 554                 return AE_NO_MEMORY;
 555
 556         buffer[0] = cmd;
 557         memcpy(buffer + 1, data, data_len);
 558
 559         msgs[0].addr = client->addr;
 560         msgs[0].flags = client->flags;
 561         msgs[0].len = data_len + 1;
 562         msgs[0].buf = buffer;
 563
 564         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 565
 566         kfree(buffer);
 567
 568         if (ret < 0) {
 569                 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
 570                 return ret;
 571         }
 572
 573         /* 1 transfer must have completed successfully */
 574         return (ret == 1) ? 0 : -EIO;
 575 }
 576
 577 static acpi_status
 578 i2c_acpi_space_handler(u32 function, acpi_physical_address command,
 579                         u32 bits, u64 *value64,
 580                         void *handler_context, void *region_context)
 581 {
 582         struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
 583         struct i2c_acpi_handler_data *data = handler_context;
 584         struct acpi_connection_info *info = &data->info;
 585         struct acpi_resource_i2c_serialbus *sb;
 586         struct i2c_adapter *adapter = data->adapter;
 587         struct i2c_client *client;
 588         struct acpi_resource *ares;
 589         u32 accessor_type = function >> 16;
 590         u8 action = function & ACPI_IO_MASK;
 591         acpi_status ret;
 592         int status;
 593
 594         ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
 595         if (ACPI_FAILURE(ret))
 596                 return ret;
 597
 598         client = kzalloc(sizeof(*client), GFP_KERNEL);
 599         if (!client) {
 600                 ret = AE_NO_MEMORY;
 601                 goto err;
 602         }
 603
 604         if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
 605                 ret = AE_BAD_PARAMETER;
 606                 goto err;
 607         }
 608
 609         client->adapter = adapter;
 610         client->addr = sb->slave_address;
 611
 612         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
 613                 client->flags |= I2C_CLIENT_TEN;
 614
 615         switch (accessor_type) {
 616         case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
 617                 if (action == ACPI_READ) {
 618                         status = i2c_smbus_read_byte(client);
 619                         if (status >= 0) {
 620                                 gsb->bdata = status;
 621                                 status = 0;
 622                         }
 623                 } else {
 624                         status = i2c_smbus_write_byte(client, gsb->bdata);
 625                 }
 626                 break;
 627
 628         case ACPI_GSB_ACCESS_ATTRIB_BYTE:
 629                 if (action == ACPI_READ) {
 630                         status = i2c_smbus_read_byte_data(client, command);
 631                         if (status >= 0) {
 632                                 gsb->bdata = status;
 633                                 status = 0;
 634                         }
 635                 } else {
 636                         status = i2c_smbus_write_byte_data(client, command,
 637                                         gsb->bdata);
 638                 }
 639                 break;
 640
 641         case ACPI_GSB_ACCESS_ATTRIB_WORD:
 642                 if (action == ACPI_READ) {
 643                         status = i2c_smbus_read_word_data(client, command);
 644                         if (status >= 0) {
 645                                 gsb->wdata = status;
 646                                 status = 0;
 647                         }
 648                 } else {
 649                         status = i2c_smbus_write_word_data(client, command,
 650                                         gsb->wdata);
 651                 }
 652                 break;
 653
 654         case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
 655                 if (action == ACPI_READ) {
 656                         status = i2c_smbus_read_block_data(client, command,
 657                                         gsb->data);
 658                         if (status >= 0) {
 659                                 gsb->len = status;
 660                                 status = 0;
 661                         }
 662                 } else {
 663                         status = i2c_smbus_write_block_data(client, command,
 664                                         gsb->len, gsb->data);
 665                 }
 666                 break;
 667
 668         case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
 669                 if (action == ACPI_READ) {
 670                         status = acpi_gsb_i2c_read_bytes(client, command,
 671                                         gsb->data, info->access_length);
 672                 } else {
 673                         status = acpi_gsb_i2c_write_bytes(client, command,
 674                                         gsb->data, info->access_length);
 675                 }
 676                 break;
 677
 678         default:
 679                 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
 680                          accessor_type, client->addr);
 681                 ret = AE_BAD_PARAMETER;
 682                 goto err;
 683         }
 684
 685         gsb->status = status;
 686
 687  err:
 688         kfree(client);
 689         ACPI_FREE(ares);
 690         return ret;
 691 }
 692
 693
 694 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
 695 {
 696         acpi_handle handle;
 697         struct i2c_acpi_handler_data *data;
 698         acpi_status status;
 699
 700         if (!adapter->dev.parent)
 701                 return -ENODEV;
 702
 703         handle = ACPI_HANDLE(adapter->dev.parent);
 704
 705         if (!handle)
 706                 return -ENODEV;
 707
 708         data = kzalloc(sizeof(struct i2c_acpi_handler_data),
 709                             GFP_KERNEL);
 710         if (!data)
 711                 return -ENOMEM;
 712
 713         data->adapter = adapter;
 714         status = acpi_bus_attach_private_data(handle, (void *)data);
 715         if (ACPI_FAILURE(status)) {
 716                 kfree(data);
 717                 return -ENOMEM;
 718         }
 719
 720         status = acpi_install_address_space_handler(handle,
 721                                 ACPI_ADR_SPACE_GSBUS,
 722                                 &i2c_acpi_space_handler,
 723                                 NULL,
 724                                 data);
 725         if (ACPI_FAILURE(status)) {
 726                 dev_err(&adapter->dev, "Error installing i2c space handler\n");
 727                 acpi_bus_detach_private_data(handle);
 728                 kfree(data);
 729                 return -ENOMEM;
 730         }
 731
 732         acpi_walk_dep_device_list(handle);
 733         return 0;
 734 }
 735
 736 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
 737 {
 738         acpi_handle handle;
 739         struct i2c_acpi_handler_data *data;
 740         acpi_status status;
 741
 742         if (!adapter->dev.parent)
 743                 return;
 744
 745         handle = ACPI_HANDLE(adapter->dev.parent);
 746
 747         if (!handle)
 748                 return;
 749
 750         acpi_remove_address_space_handler(handle,
 751                                 ACPI_ADR_SPACE_GSBUS,
 752                                 &i2c_acpi_space_handler);
 753
 754         status = acpi_bus_get_private_data(handle, (void **)&data);
 755         if (ACPI_SUCCESS(status))
 756                 kfree(data);
 757
 758         acpi_bus_detach_private_data(handle);
 759 }
 760 #endif /* CONFIG_ACPI_I2C_OPREGION */