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_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         acpi_handle handle;
 268
 269         if (!has_acpi_companion(&adap->dev))
 270                 return;
 271
 272         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 273                                      I2C_ACPI_MAX_SCAN_DEPTH,
 274                                      i2c_acpi_add_device, NULL,
 275                                      adap, NULL);
 276         if (ACPI_FAILURE(status))
 277                 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
 278
 279         if (!adap->dev.parent)
 280                 return;
 281
 282         handle = ACPI_HANDLE(adap->dev.parent);
 283         if (!handle)
 284                 return;
 285
 286         acpi_walk_dep_device_list(handle);
 287 }
 288
 289 const struct acpi_device_id *
 290 i2c_acpi_match_device(const struct acpi_device_id *matches,
 291                       struct i2c_client *client)
 292 {
 293         if (!(client && matches))
 294                 return NULL;
 295
 296         return acpi_match_device(matches, &client->dev);
 297 }
 298
 299 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
 300         /*
 301          * These Silead touchscreen controllers only work at 400KHz, for
 302          * some reason they do not work at 100KHz. On some devices the ACPI
 303          * tables list another device at their bus as only being capable
 304          * of 100KHz, testing has shown that these other devices work fine
 305          * at 400KHz (as can be expected of any recent i2c hw) so we force
 306          * the speed of the bus to 400 KHz if a Silead device is present.
 307          */
 308         { "MSSL1680", 0 },
 309         {}
 310 };
 311
 312 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
 313                                            void *data, void **return_value)
 314 {
 315         struct i2c_acpi_lookup *lookup = data;
 316         struct acpi_device *adev;
 317
 318         if (acpi_bus_get_device(handle, &adev))
 319                 return AE_OK;
 320
 321         if (i2c_acpi_do_lookup(adev, lookup))
 322                 return AE_OK;
 323
 324         if (lookup->search_handle != lookup->adapter_handle)
 325                 return AE_OK;
 326
 327         if (lookup->speed <= lookup->min_speed)
 328                 lookup->min_speed = lookup->speed;
 329
 330         if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
 331                 lookup->force_speed = 400000;
 332
 333         return AE_OK;
 334 }
 335
 336 /**
 337  * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
 338  * @dev: The device owning the bus
 339  *
 340  * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
 341  * devices connected to this bus and use the speed of slowest device.
 342  *
 343  * Returns the speed in Hz or zero
 344  */
 345 u32 i2c_acpi_find_bus_speed(struct device *dev)
 346 {
 347         struct i2c_acpi_lookup lookup;
 348         struct i2c_board_info dummy;
 349         acpi_status status;
 350
 351         if (!has_acpi_companion(dev))
 352                 return 0;
 353
 354         memset(&lookup, 0, sizeof(lookup));
 355         lookup.search_handle = ACPI_HANDLE(dev);
 356         lookup.min_speed = UINT_MAX;
 357         lookup.info = &dummy;
 358         lookup.index = -1;
 359
 360         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 361                                      I2C_ACPI_MAX_SCAN_DEPTH,
 362                                      i2c_acpi_lookup_speed, NULL,
 363                                      &lookup, NULL);
 364
 365         if (ACPI_FAILURE(status)) {
 366                 dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
 367                 return 0;
 368         }
 369
 370         if (lookup.force_speed) {
 371                 if (lookup.force_speed != lookup.min_speed)
 372                         dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
 373                                  lookup.min_speed, lookup.force_speed);
 374                 return lookup.force_speed;
 375         } else if (lookup.min_speed != UINT_MAX) {
 376                 return lookup.min_speed;
 377         } else {
 378                 return 0;
 379         }
 380 }
 381 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
 382
 383 static int i2c_acpi_find_match_adapter(struct device *dev, const void *data)
 384 {
 385         struct i2c_adapter *adapter = i2c_verify_adapter(dev);
 386
 387         if (!adapter)
 388                 return 0;
 389
 390         return ACPI_HANDLE(dev) == (acpi_handle)data;
 391 }
 392
 393 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 394 {
 395         struct device *dev;
 396
 397         dev = bus_find_device(&i2c_bus_type, NULL, handle,
 398                               i2c_acpi_find_match_adapter);
 399
 400         return dev ? i2c_verify_adapter(dev) : NULL;
 401 }
 402 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 403
 404 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 405 {
 406         struct device *dev;
 407         struct i2c_client *client;
 408
 409         dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
 410         if (!dev)
 411                 return NULL;
 412
 413         client = i2c_verify_client(dev);
 414         if (!client)
 415                 put_device(dev);
 416
 417         return client;
 418 }
 419
 420 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
 421                            void *arg)
 422 {
 423         struct acpi_device *adev = arg;
 424         struct i2c_board_info info;
 425         acpi_handle adapter_handle;
 426         struct i2c_adapter *adapter;
 427         struct i2c_client *client;
 428
 429         switch (value) {
 430         case ACPI_RECONFIG_DEVICE_ADD:
 431                 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
 432                         break;
 433
 434                 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
 435                 if (!adapter)
 436                         break;
 437
 438                 i2c_acpi_register_device(adapter, adev, &info);
 439                 put_device(&adapter->dev);
 440                 break;
 441         case ACPI_RECONFIG_DEVICE_REMOVE:
 442                 if (!acpi_device_enumerated(adev))
 443                         break;
 444
 445                 client = i2c_acpi_find_client_by_adev(adev);
 446                 if (!client)
 447                         break;
 448
 449                 i2c_unregister_device(client);
 450                 put_device(&client->dev);
 451                 break;
 452         }
 453
 454         return NOTIFY_OK;
 455 }
 456
 457 struct notifier_block i2c_acpi_notifier = {
 458         .notifier_call = i2c_acpi_notify,
 459 };
 460
 461 /**
 462  * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
 463  * @dev:     Device owning the ACPI resources to get the client from
 464  * @index:   Index of ACPI resource to get
 465  * @info:    describes the I2C device; note this is modified (addr gets set)
 466  * Context: can sleep
 467  *
 468  * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
 469  * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
 470  * resources, in that case this function can be used to create an i2c-client
 471  * for other I2cSerialBus resources in the Current Resource Settings table.
 472  *
 473  * Also see i2c_new_device, which this function calls to create the i2c-client.
 474  *
 475  * Returns a pointer to the new i2c-client, or error pointer in case of failure.
 476  * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
 477  */
 478 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
 479                                        struct i2c_board_info *info)
 480 {
 481         struct i2c_acpi_lookup lookup;
 482         struct i2c_adapter *adapter;
 483         struct i2c_client *client;
 484         struct acpi_device *adev;
 485         LIST_HEAD(resource_list);
 486         int ret;
 487
 488         adev = ACPI_COMPANION(dev);
 489         if (!adev)
 490                 return ERR_PTR(-EINVAL);
 491
 492         memset(&lookup, 0, sizeof(lookup));
 493         lookup.info = info;
 494         lookup.device_handle = acpi_device_handle(adev);
 495         lookup.index = index;
 496
 497         ret = acpi_dev_get_resources(adev, &resource_list,
 498                                      i2c_acpi_fill_info, &lookup);
 499         if (ret < 0)
 500                 return ERR_PTR(ret);
 501
 502         acpi_dev_free_resource_list(&resource_list);
 503
 504         if (!info->addr)
 505                 return ERR_PTR(-EADDRNOTAVAIL);
 506
 507         adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
 508         if (!adapter)
 509                 return ERR_PTR(-EPROBE_DEFER);
 510
 511         client = i2c_new_device(adapter, info);
 512         if (!client)
 513                 return ERR_PTR(-ENODEV);
 514
 515         return client;
 516 }
 517 EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
 518
 519 #ifdef CONFIG_ACPI_I2C_OPREGION
 520 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
 521                 u8 cmd, u8 *data, u8 data_len)
 522 {
 523
 524         struct i2c_msg msgs[2];
 525         int ret;
 526         u8 *buffer;
 527
 528         buffer = kzalloc(data_len, GFP_KERNEL);
 529         if (!buffer)
 530                 return AE_NO_MEMORY;
 531
 532         msgs[0].addr = client->addr;
 533         msgs[0].flags = client->flags;
 534         msgs[0].len = 1;
 535         msgs[0].buf = &cmd;
 536
 537         msgs[1].addr = client->addr;
 538         msgs[1].flags = client->flags | I2C_M_RD;
 539         msgs[1].len = data_len;
 540         msgs[1].buf = buffer;
 541
 542         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 543         if (ret < 0) {
 544                 /* Getting a NACK is unfortunately normal with some DSTDs */
 545                 if (ret == -EREMOTEIO)
 546                         dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 547                                 data_len, client->addr, cmd, ret);
 548                 else
 549                         dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 550                                 data_len, client->addr, cmd, ret);
 551         /* 2 transfers must have completed successfully */
 552         } else if (ret == 2) {
 553                 memcpy(data, buffer, data_len);
 554                 ret = 0;
 555         } else {
 556                 ret = -EIO;
 557         }
 558
 559         kfree(buffer);
 560         return ret;
 561 }
 562
 563 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
 564                 u8 cmd, u8 *data, u8 data_len)
 565 {
 566
 567         struct i2c_msg msgs[1];
 568         u8 *buffer;
 569         int ret = AE_OK;
 570
 571         buffer = kzalloc(data_len + 1, GFP_KERNEL);
 572         if (!buffer)
 573                 return AE_NO_MEMORY;
 574
 575         buffer[0] = cmd;
 576         memcpy(buffer + 1, data, data_len);
 577
 578         msgs[0].addr = client->addr;
 579         msgs[0].flags = client->flags;
 580         msgs[0].len = data_len + 1;
 581         msgs[0].buf = buffer;
 582
 583         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 584
 585         kfree(buffer);
 586
 587         if (ret < 0) {
 588                 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
 589                 return ret;
 590         }
 591
 592         /* 1 transfer must have completed successfully */
 593         return (ret == 1) ? 0 : -EIO;
 594 }
 595
 596 static acpi_status
 597 i2c_acpi_space_handler(u32 function, acpi_physical_address command,
 598                         u32 bits, u64 *value64,
 599                         void *handler_context, void *region_context)
 600 {
 601         struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
 602         struct i2c_acpi_handler_data *data = handler_context;
 603         struct acpi_connection_info *info = &data->info;
 604         struct acpi_resource_i2c_serialbus *sb;
 605         struct i2c_adapter *adapter = data->adapter;
 606         struct i2c_client *client;
 607         struct acpi_resource *ares;
 608         u32 accessor_type = function >> 16;
 609         u8 action = function & ACPI_IO_MASK;
 610         acpi_status ret;
 611         int status;
 612
 613         ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
 614         if (ACPI_FAILURE(ret))
 615                 return ret;
 616
 617         client = kzalloc(sizeof(*client), GFP_KERNEL);
 618         if (!client) {
 619                 ret = AE_NO_MEMORY;
 620                 goto err;
 621         }
 622
 623         if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
 624                 ret = AE_BAD_PARAMETER;
 625                 goto err;
 626         }
 627
 628         client->adapter = adapter;
 629         client->addr = sb->slave_address;
 630
 631         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
 632                 client->flags |= I2C_CLIENT_TEN;
 633
 634         switch (accessor_type) {
 635         case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
 636                 if (action == ACPI_READ) {
 637                         status = i2c_smbus_read_byte(client);
 638                         if (status >= 0) {
 639                                 gsb->bdata = status;
 640                                 status = 0;
 641                         }
 642                 } else {
 643                         status = i2c_smbus_write_byte(client, gsb->bdata);
 644                 }
 645                 break;
 646
 647         case ACPI_GSB_ACCESS_ATTRIB_BYTE:
 648                 if (action == ACPI_READ) {
 649                         status = i2c_smbus_read_byte_data(client, command);
 650                         if (status >= 0) {
 651                                 gsb->bdata = status;
 652                                 status = 0;
 653                         }
 654                 } else {
 655                         status = i2c_smbus_write_byte_data(client, command,
 656                                         gsb->bdata);
 657                 }
 658                 break;
 659
 660         case ACPI_GSB_ACCESS_ATTRIB_WORD:
 661                 if (action == ACPI_READ) {
 662                         status = i2c_smbus_read_word_data(client, command);
 663                         if (status >= 0) {
 664                                 gsb->wdata = status;
 665                                 status = 0;
 666                         }
 667                 } else {
 668                         status = i2c_smbus_write_word_data(client, command,
 669                                         gsb->wdata);
 670                 }
 671                 break;
 672
 673         case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
 674                 if (action == ACPI_READ) {
 675                         status = i2c_smbus_read_block_data(client, command,
 676                                         gsb->data);
 677                         if (status >= 0) {
 678                                 gsb->len = status;
 679                                 status = 0;
 680                         }
 681                 } else {
 682                         status = i2c_smbus_write_block_data(client, command,
 683                                         gsb->len, gsb->data);
 684                 }
 685                 break;
 686
 687         case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
 688                 if (action == ACPI_READ) {
 689                         status = acpi_gsb_i2c_read_bytes(client, command,
 690                                         gsb->data, info->access_length);
 691                 } else {
 692                         status = acpi_gsb_i2c_write_bytes(client, command,
 693                                         gsb->data, info->access_length);
 694                 }
 695                 break;
 696
 697         default:
 698                 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
 699                          accessor_type, client->addr);
 700                 ret = AE_BAD_PARAMETER;
 701                 goto err;
 702         }
 703
 704         gsb->status = status;
 705
 706  err:
 707         kfree(client);
 708         ACPI_FREE(ares);
 709         return ret;
 710 }
 711
 712
 713 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
 714 {
 715         acpi_handle handle;
 716         struct i2c_acpi_handler_data *data;
 717         acpi_status status;
 718
 719         if (!adapter->dev.parent)
 720                 return -ENODEV;
 721
 722         handle = ACPI_HANDLE(adapter->dev.parent);
 723
 724         if (!handle)
 725                 return -ENODEV;
 726
 727         data = kzalloc(sizeof(struct i2c_acpi_handler_data),
 728                             GFP_KERNEL);
 729         if (!data)
 730                 return -ENOMEM;
 731
 732         data->adapter = adapter;
 733         status = acpi_bus_attach_private_data(handle, (void *)data);
 734         if (ACPI_FAILURE(status)) {
 735                 kfree(data);
 736                 return -ENOMEM;
 737         }
 738
 739         status = acpi_install_address_space_handler(handle,
 740                                 ACPI_ADR_SPACE_GSBUS,
 741                                 &i2c_acpi_space_handler,
 742                                 NULL,
 743                                 data);
 744         if (ACPI_FAILURE(status)) {
 745                 dev_err(&adapter->dev, "Error installing i2c space handler\n");
 746                 acpi_bus_detach_private_data(handle);
 747                 kfree(data);
 748                 return -ENOMEM;
 749         }
 750
 751         return 0;
 752 }
 753
 754 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
 755 {
 756         acpi_handle handle;
 757         struct i2c_acpi_handler_data *data;
 758         acpi_status status;
 759
 760         if (!adapter->dev.parent)
 761                 return;
 762
 763         handle = ACPI_HANDLE(adapter->dev.parent);
 764
 765         if (!handle)
 766                 return;
 767
 768         acpi_remove_address_space_handler(handle,
 769                                 ACPI_ADR_SPACE_GSBUS,
 770                                 &i2c_acpi_space_handler);
 771
 772         status = acpi_bus_get_private_data(handle, (void **)&data);
 773         if (ACPI_SUCCESS(status))
 774                 kfree(data);
 775
 776         acpi_bus_detach_private_data(handle);
 777 }
 778 #endif /* CONFIG_ACPI_I2C_OPREGION */