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 (IS_ERR(i2c_new_client_device(adapter, info)))
 229                 adev->power.flags.ignore_parent = false;
 230 }
 231
 232 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
 233                                        void *data, void **return_value)
 234 {
 235         struct i2c_adapter *adapter = data;
 236         struct acpi_device *adev;
 237         struct i2c_board_info info;
 238
 239         if (acpi_bus_get_device(handle, &adev))
 240                 return AE_OK;
 241
 242         if (i2c_acpi_get_info(adev, &info, adapter, NULL))
 243                 return AE_OK;
 244
 245         i2c_acpi_register_device(adapter, adev, &info);
 246
 247         return AE_OK;
 248 }
 249
 250 #define I2C_ACPI_MAX_SCAN_DEPTH 32
 251
 252 /**
 253  * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
 254  * @adap: pointer to adapter
 255  *
 256  * Enumerate all I2C slave devices behind this adapter by walking the ACPI
 257  * namespace. When a device is found it will be added to the Linux device
 258  * model and bound to the corresponding ACPI handle.
 259  */
 260 void i2c_acpi_register_devices(struct i2c_adapter *adap)
 261 {
 262         acpi_status status;
 263         acpi_handle handle;
 264
 265         if (!has_acpi_companion(&adap->dev))
 266                 return;
 267
 268         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 269                                      I2C_ACPI_MAX_SCAN_DEPTH,
 270                                      i2c_acpi_add_device, NULL,
 271                                      adap, NULL);
 272         if (ACPI_FAILURE(status))
 273                 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
 274
 275         if (!adap->dev.parent)
 276                 return;
 277
 278         handle = ACPI_HANDLE(adap->dev.parent);
 279         if (!handle)
 280                 return;
 281
 282         acpi_walk_dep_device_list(handle);
 283 }
 284
 285 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
 286         /*
 287          * These Silead touchscreen controllers only work at 400KHz, for
 288          * some reason they do not work at 100KHz. On some devices the ACPI
 289          * tables list another device at their bus as only being capable
 290          * of 100KHz, testing has shown that these other devices work fine
 291          * at 400KHz (as can be expected of any recent i2c hw) so we force
 292          * the speed of the bus to 400 KHz if a Silead device is present.
 293          */
 294         { "MSSL1680", 0 },
 295         {}
 296 };
 297
 298 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
 299                                            void *data, void **return_value)
 300 {
 301         struct i2c_acpi_lookup *lookup = data;
 302         struct acpi_device *adev;
 303
 304         if (acpi_bus_get_device(handle, &adev))
 305                 return AE_OK;
 306
 307         if (i2c_acpi_do_lookup(adev, lookup))
 308                 return AE_OK;
 309
 310         if (lookup->search_handle != lookup->adapter_handle)
 311                 return AE_OK;
 312
 313         if (lookup->speed <= lookup->min_speed)
 314                 lookup->min_speed = lookup->speed;
 315
 316         if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
 317                 lookup->force_speed = I2C_MAX_FAST_MODE_FREQ;
 318
 319         return AE_OK;
 320 }
 321
 322 /**
 323  * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
 324  * @dev: The device owning the bus
 325  *
 326  * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
 327  * devices connected to this bus and use the speed of slowest device.
 328  *
 329  * Returns the speed in Hz or zero
 330  */
 331 u32 i2c_acpi_find_bus_speed(struct device *dev)
 332 {
 333         struct i2c_acpi_lookup lookup;
 334         struct i2c_board_info dummy;
 335         acpi_status status;
 336
 337         if (!has_acpi_companion(dev))
 338                 return 0;
 339
 340         memset(&lookup, 0, sizeof(lookup));
 341         lookup.search_handle = ACPI_HANDLE(dev);
 342         lookup.min_speed = UINT_MAX;
 343         lookup.info = &dummy;
 344         lookup.index = -1;
 345
 346         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 347                                      I2C_ACPI_MAX_SCAN_DEPTH,
 348                                      i2c_acpi_lookup_speed, NULL,
 349                                      &lookup, NULL);
 350
 351         if (ACPI_FAILURE(status)) {
 352                 dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
 353                 return 0;
 354         }
 355
 356         if (lookup.force_speed) {
 357                 if (lookup.force_speed != lookup.min_speed)
 358                         dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
 359                                  lookup.min_speed, lookup.force_speed);
 360                 return lookup.force_speed;
 361         } else if (lookup.min_speed != UINT_MAX) {
 362                 return lookup.min_speed;
 363         } else {
 364                 return 0;
 365         }
 366 }
 367 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
 368
 369 static int i2c_acpi_find_match_adapter(struct device *dev, const void *data)
 370 {
 371         struct i2c_adapter *adapter = i2c_verify_adapter(dev);
 372
 373         if (!adapter)
 374                 return 0;
 375
 376         return ACPI_HANDLE(dev) == (acpi_handle)data;
 377 }
 378
 379 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 380 {
 381         struct device *dev;
 382
 383         dev = bus_find_device(&i2c_bus_type, NULL, handle,
 384                               i2c_acpi_find_match_adapter);
 385
 386         return dev ? i2c_verify_adapter(dev) : NULL;
 387 }
 388 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 389
 390 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 391 {
 392         struct device *dev;
 393         struct i2c_client *client;
 394
 395         dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
 396         if (!dev)
 397                 return NULL;
 398
 399         client = i2c_verify_client(dev);
 400         if (!client)
 401                 put_device(dev);
 402
 403         return client;
 404 }
 405
 406 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
 407                            void *arg)
 408 {
 409         struct acpi_device *adev = arg;
 410         struct i2c_board_info info;
 411         acpi_handle adapter_handle;
 412         struct i2c_adapter *adapter;
 413         struct i2c_client *client;
 414
 415         switch (value) {
 416         case ACPI_RECONFIG_DEVICE_ADD:
 417                 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
 418                         break;
 419
 420                 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
 421                 if (!adapter)
 422                         break;
 423
 424                 i2c_acpi_register_device(adapter, adev, &info);
 425                 break;
 426         case ACPI_RECONFIG_DEVICE_REMOVE:
 427                 if (!acpi_device_enumerated(adev))
 428                         break;
 429
 430                 client = i2c_acpi_find_client_by_adev(adev);
 431                 if (!client)
 432                         break;
 433
 434                 i2c_unregister_device(client);
 435                 put_device(&client->dev);
 436                 break;
 437         }
 438
 439         return NOTIFY_OK;
 440 }
 441
 442 struct notifier_block i2c_acpi_notifier = {
 443         .notifier_call = i2c_acpi_notify,
 444 };
 445
 446 /**
 447  * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
 448  * @dev:     Device owning the ACPI resources to get the client from
 449  * @index:   Index of ACPI resource to get
 450  * @info:    describes the I2C device; note this is modified (addr gets set)
 451  * Context: can sleep
 452  *
 453  * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
 454  * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
 455  * resources, in that case this function can be used to create an i2c-client
 456  * for other I2cSerialBus resources in the Current Resource Settings table.
 457  *
 458  * Also see i2c_new_client_device, which this function calls to create the
 459  * i2c-client.
 460  *
 461  * Returns a pointer to the new i2c-client, or error pointer in case of failure.
 462  * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
 463  */
 464 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
 465                                        struct i2c_board_info *info)
 466 {
 467         struct acpi_device *adev = ACPI_COMPANION(dev);
 468         struct i2c_acpi_lookup lookup;
 469         struct i2c_adapter *adapter;
 470         LIST_HEAD(resource_list);
 471         int ret;
 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         return i2c_new_client_device(adapter, info);
 493 }
 494 EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
 495
 496 #ifdef CONFIG_ACPI_I2C_OPREGION
 497 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
 498                 u8 cmd, u8 *data, u8 data_len)
 499 {
 500
 501         struct i2c_msg msgs[2];
 502         int ret;
 503         u8 *buffer;
 504
 505         buffer = kzalloc(data_len, GFP_KERNEL);
 506         if (!buffer)
 507                 return AE_NO_MEMORY;
 508
 509         msgs[0].addr = client->addr;
 510         msgs[0].flags = client->flags;
 511         msgs[0].len = 1;
 512         msgs[0].buf = &cmd;
 513
 514         msgs[1].addr = client->addr;
 515         msgs[1].flags = client->flags | I2C_M_RD;
 516         msgs[1].len = data_len;
 517         msgs[1].buf = buffer;
 518
 519         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 520         if (ret < 0) {
 521                 /* Getting a NACK is unfortunately normal with some DSTDs */
 522                 if (ret == -EREMOTEIO)
 523                         dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 524                                 data_len, client->addr, cmd, ret);
 525                 else
 526                         dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 527                                 data_len, client->addr, cmd, ret);
 528         /* 2 transfers must have completed successfully */
 529         } else if (ret == 2) {
 530                 memcpy(data, buffer, data_len);
 531                 ret = 0;
 532         } else {
 533                 ret = -EIO;
 534         }
 535
 536         kfree(buffer);
 537         return ret;
 538 }
 539
 540 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
 541                 u8 cmd, u8 *data, u8 data_len)
 542 {
 543
 544         struct i2c_msg msgs[1];
 545         u8 *buffer;
 546         int ret = AE_OK;
 547
 548         buffer = kzalloc(data_len + 1, GFP_KERNEL);
 549         if (!buffer)
 550                 return AE_NO_MEMORY;
 551
 552         buffer[0] = cmd;
 553         memcpy(buffer + 1, data, data_len);
 554
 555         msgs[0].addr = client->addr;
 556         msgs[0].flags = client->flags;
 557         msgs[0].len = data_len + 1;
 558         msgs[0].buf = buffer;
 559
 560         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 561
 562         kfree(buffer);
 563
 564         if (ret < 0) {
 565                 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
 566                 return ret;
 567         }
 568
 569         /* 1 transfer must have completed successfully */
 570         return (ret == 1) ? 0 : -EIO;
 571 }
 572
 573 static acpi_status
 574 i2c_acpi_space_handler(u32 function, acpi_physical_address command,
 575                         u32 bits, u64 *value64,
 576                         void *handler_context, void *region_context)
 577 {
 578         struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
 579         struct i2c_acpi_handler_data *data = handler_context;
 580         struct acpi_connection_info *info = &data->info;
 581         struct acpi_resource_i2c_serialbus *sb;
 582         struct i2c_adapter *adapter = data->adapter;
 583         struct i2c_client *client;
 584         struct acpi_resource *ares;
 585         u32 accessor_type = function >> 16;
 586         u8 action = function & ACPI_IO_MASK;
 587         acpi_status ret;
 588         int status;
 589
 590         ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
 591         if (ACPI_FAILURE(ret))
 592                 return ret;
 593
 594         client = kzalloc(sizeof(*client), GFP_KERNEL);
 595         if (!client) {
 596                 ret = AE_NO_MEMORY;
 597                 goto err;
 598         }
 599
 600         if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
 601                 ret = AE_BAD_PARAMETER;
 602                 goto err;
 603         }
 604
 605         client->adapter = adapter;
 606         client->addr = sb->slave_address;
 607
 608         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
 609                 client->flags |= I2C_CLIENT_TEN;
 610
 611         switch (accessor_type) {
 612         case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
 613                 if (action == ACPI_READ) {
 614                         status = i2c_smbus_read_byte(client);
 615                         if (status >= 0) {
 616                                 gsb->bdata = status;
 617                                 status = 0;
 618                         }
 619                 } else {
 620                         status = i2c_smbus_write_byte(client, gsb->bdata);
 621                 }
 622                 break;
 623
 624         case ACPI_GSB_ACCESS_ATTRIB_BYTE:
 625                 if (action == ACPI_READ) {
 626                         status = i2c_smbus_read_byte_data(client, command);
 627                         if (status >= 0) {
 628                                 gsb->bdata = status;
 629                                 status = 0;
 630                         }
 631                 } else {
 632                         status = i2c_smbus_write_byte_data(client, command,
 633                                         gsb->bdata);
 634                 }
 635                 break;
 636
 637         case ACPI_GSB_ACCESS_ATTRIB_WORD:
 638                 if (action == ACPI_READ) {
 639                         status = i2c_smbus_read_word_data(client, command);
 640                         if (status >= 0) {
 641                                 gsb->wdata = status;
 642                                 status = 0;
 643                         }
 644                 } else {
 645                         status = i2c_smbus_write_word_data(client, command,
 646                                         gsb->wdata);
 647                 }
 648                 break;
 649
 650         case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
 651                 if (action == ACPI_READ) {
 652                         status = i2c_smbus_read_block_data(client, command,
 653                                         gsb->data);
 654                         if (status >= 0) {
 655                                 gsb->len = status;
 656                                 status = 0;
 657                         }
 658                 } else {
 659                         status = i2c_smbus_write_block_data(client, command,
 660                                         gsb->len, gsb->data);
 661                 }
 662                 break;
 663
 664         case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
 665                 if (action == ACPI_READ) {
 666                         status = acpi_gsb_i2c_read_bytes(client, command,
 667                                         gsb->data, info->access_length);
 668                 } else {
 669                         status = acpi_gsb_i2c_write_bytes(client, command,
 670                                         gsb->data, info->access_length);
 671                 }
 672                 break;
 673
 674         default:
 675                 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
 676                          accessor_type, client->addr);
 677                 ret = AE_BAD_PARAMETER;
 678                 goto err;
 679         }
 680
 681         gsb->status = status;
 682
 683  err:
 684         kfree(client);
 685         ACPI_FREE(ares);
 686         return ret;
 687 }
 688
 689
 690 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
 691 {
 692         acpi_handle handle;
 693         struct i2c_acpi_handler_data *data;
 694         acpi_status status;
 695
 696         if (!adapter->dev.parent)
 697                 return -ENODEV;
 698
 699         handle = ACPI_HANDLE(adapter->dev.parent);
 700
 701         if (!handle)
 702                 return -ENODEV;
 703
 704         data = kzalloc(sizeof(struct i2c_acpi_handler_data),
 705                             GFP_KERNEL);
 706         if (!data)
 707                 return -ENOMEM;
 708
 709         data->adapter = adapter;
 710         status = acpi_bus_attach_private_data(handle, (void *)data);
 711         if (ACPI_FAILURE(status)) {
 712                 kfree(data);
 713                 return -ENOMEM;
 714         }
 715
 716         status = acpi_install_address_space_handler(handle,
 717                                 ACPI_ADR_SPACE_GSBUS,
 718                                 &i2c_acpi_space_handler,
 719                                 NULL,
 720                                 data);
 721         if (ACPI_FAILURE(status)) {
 722                 dev_err(&adapter->dev, "Error installing i2c space handler\n");
 723                 acpi_bus_detach_private_data(handle);
 724                 kfree(data);
 725                 return -ENOMEM;
 726         }
 727
 728         return 0;
 729 }
 730
 731 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
 732 {
 733         acpi_handle handle;
 734         struct i2c_acpi_handler_data *data;
 735         acpi_status status;
 736
 737         if (!adapter->dev.parent)
 738                 return;
 739
 740         handle = ACPI_HANDLE(adapter->dev.parent);
 741
 742         if (!handle)
 743                 return;
 744
 745         acpi_remove_address_space_handler(handle,
 746                                 ACPI_ADR_SPACE_GSBUS,
 747                                 &i2c_acpi_space_handler);
 748
 749         status = acpi_bus_get_private_data(handle, (void **)&data);
 750         if (ACPI_SUCCESS(status))
 751                 kfree(data);
 752
 753         acpi_bus_detach_private_data(handle);
 754 }
 755 #endif /* CONFIG_ACPI_I2C_OPREGION */