linux/drivers/i2c/i2c-core-acpi.c
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   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
  18struct i2c_acpi_handler_data {
  19        struct acpi_connection_info info;
  20        struct i2c_adapter *adapter;
  21};
  22
  23struct gsb_buffer {
  24        u8      status;
  25        u8      len;
  26        union {
  27                u16     wdata;
  28                u8      bdata;
  29                u8      data[0];
  30        };
  31} __packed;
  32
  33struct 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 */
  55bool 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}
  70EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource);
  71
  72static 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
  99static 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
 108static 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
 136static 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 */
 155int 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
 177static 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
 221static 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
 232static 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 */
 260void i2c_acpi_register_devices(struct i2c_adapter *adap)
 261{
 262        struct acpi_device *adev;
 263        acpi_status status;
 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        adev = ACPI_COMPANION(adap->dev.parent);
 279        if (!adev)
 280                return;
 281
 282        acpi_dev_clear_dependencies(adev);
 283}
 284
 285static 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
 298static 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 */
 331u32 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}
 367EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
 368
 369static 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
 379struct 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}
 388EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 389
 390static 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
 406static 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
 442struct 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 */
 464struct 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}
 494EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
 495
 496#ifdef CONFIG_ACPI_I2C_OPREGION
 497static 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
 540static 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
 573static acpi_status
 574i2c_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
 690int 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
 731void 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 */
 756