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                 DECLARE_FLEX_ARRAY(u8, data);
  30         };
  31 } __packed;
  32
  33 struct i2c_acpi_lookup {
  34         struct i2c_board_info *info;
  35         acpi_handle adapter_handle;
  36         acpi_handle device_handle;
  37         acpi_handle search_handle;
  38         int n;
  39         int index;
  40         u32 speed;
  41         u32 min_speed;
  42         u32 force_speed;
  43 };
  44
  45 /**
  46  * i2c_acpi_get_i2c_resource - Gets I2cSerialBus resource if type matches
  47  * @ares:       ACPI resource
  48  * @i2c:        Pointer to I2cSerialBus resource will be returned here
  49  *
  50  * Checks if the given ACPI resource is of type I2cSerialBus.
  51  * In this case, returns a pointer to it to the caller.
  52  *
  53  * Returns true if resource type is of I2cSerialBus, otherwise false.
  54  */
  55 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
  56                                struct acpi_resource_i2c_serialbus **i2c)
  57 {
  58         struct acpi_resource_i2c_serialbus *sb;
  59
  60         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
  61                 return false;
  62
  63         sb = &ares->data.i2c_serial_bus;
  64         if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
  65                 return false;
  66
  67         *i2c = sb;
  68         return true;
  69 }
  70 EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource);
  71
  72 static int i2c_acpi_resource_count(struct acpi_resource *ares, void *data)
  73 {
  74         struct acpi_resource_i2c_serialbus *sb;
  75         int *count = data;
  76
  77         if (i2c_acpi_get_i2c_resource(ares, &sb))
  78                 *count = *count + 1;
  79
  80         return 1;
  81 }
  82
  83 /**
  84  * i2c_acpi_client_count - Count the number of I2cSerialBus resources
  85  * @adev:       ACPI device
  86  *
  87  * Returns the number of I2cSerialBus resources in the ACPI-device's
  88  * resource-list; or a negative error code.
  89  */
  90 int i2c_acpi_client_count(struct acpi_device *adev)
  91 {
  92         int ret, count = 0;
  93         LIST_HEAD(r);
  94
  95         ret = acpi_dev_get_resources(adev, &r, i2c_acpi_resource_count, &count);
  96         if (ret < 0)
  97                 return ret;
  98
  99         acpi_dev_free_resource_list(&r);
 100         return count;
 101 }
 102 EXPORT_SYMBOL_GPL(i2c_acpi_client_count);
 103
 104 static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
 105 {
 106         struct i2c_acpi_lookup *lookup = data;
 107         struct i2c_board_info *info = lookup->info;
 108         struct acpi_resource_i2c_serialbus *sb;
 109         acpi_status status;
 110
 111         if (info->addr || !i2c_acpi_get_i2c_resource(ares, &sb))
 112                 return 1;
 113
 114         if (lookup->index != -1 && lookup->n++ != lookup->index)
 115                 return 1;
 116
 117         status = acpi_get_handle(lookup->device_handle,
 118                                  sb->resource_source.string_ptr,
 119                                  &lookup->adapter_handle);
 120         if (ACPI_FAILURE(status))
 121                 return 1;
 122
 123         info->addr = sb->slave_address;
 124         lookup->speed = sb->connection_speed;
 125         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
 126                 info->flags |= I2C_CLIENT_TEN;
 127
 128         return 1;
 129 }
 130
 131 static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
 132         /*
 133          * ACPI video acpi_devices, which are handled by the acpi-video driver
 134          * sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these.
 135          */
 136         { ACPI_VIDEO_HID, 0 },
 137         {}
 138 };
 139
 140 struct i2c_acpi_irq_context {
 141         int irq;
 142         bool wake_capable;
 143 };
 144
 145 static int i2c_acpi_do_lookup(struct acpi_device *adev,
 146                               struct i2c_acpi_lookup *lookup)
 147 {
 148         struct i2c_board_info *info = lookup->info;
 149         struct list_head resource_list;
 150         int ret;
 151
 152         if (acpi_bus_get_status(adev))
 153                 return -EINVAL;
 154
 155         if (!acpi_dev_ready_for_enumeration(adev))
 156                 return -ENODEV;
 157
 158         if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)
 159                 return -ENODEV;
 160
 161         memset(info, 0, sizeof(*info));
 162         lookup->device_handle = acpi_device_handle(adev);
 163
 164         /* Look up for I2cSerialBus resource */
 165         INIT_LIST_HEAD(&resource_list);
 166         ret = acpi_dev_get_resources(adev, &resource_list,
 167                                      i2c_acpi_fill_info, lookup);
 168         acpi_dev_free_resource_list(&resource_list);
 169
 170         if (ret < 0 || !info->addr)
 171                 return -EINVAL;
 172
 173         return 0;
 174 }
 175
 176 static int i2c_acpi_add_irq_resource(struct acpi_resource *ares, void *data)
 177 {
 178         struct i2c_acpi_irq_context *irq_ctx = data;
 179         struct resource r;
 180
 181         if (irq_ctx->irq > 0)
 182                 return 1;
 183
 184         if (!acpi_dev_resource_interrupt(ares, 0, &r))
 185                 return 1;
 186
 187         irq_ctx->irq = i2c_dev_irq_from_resources(&r, 1);
 188         irq_ctx->wake_capable = r.flags & IORESOURCE_IRQ_WAKECAPABLE;
 189
 190         return 1; /* No need to add resource to the list */
 191 }
 192
 193 /**
 194  * i2c_acpi_get_irq - get device IRQ number from ACPI
 195  * @client: Pointer to the I2C client device
 196  * @wake_capable: Set to true if the IRQ is wake capable
 197  *
 198  * Find the IRQ number used by a specific client device.
 199  *
 200  * Return: The IRQ number or an error code.
 201  */
 202 int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable)
 203 {
 204         struct acpi_device *adev = ACPI_COMPANION(&client->dev);
 205         struct list_head resource_list;
 206         struct i2c_acpi_irq_context irq_ctx = {
 207                 .irq = -ENOENT,
 208         };
 209         int ret;
 210
 211         INIT_LIST_HEAD(&resource_list);
 212
 213         ret = acpi_dev_get_resources(adev, &resource_list,
 214                                      i2c_acpi_add_irq_resource, &irq_ctx);
 215         if (ret < 0)
 216                 return ret;
 217
 218         acpi_dev_free_resource_list(&resource_list);
 219
 220         if (irq_ctx.irq == -ENOENT)
 221                 irq_ctx.irq = acpi_dev_gpio_irq_wake_get(adev, 0, &irq_ctx.wake_capable);
 222
 223         if (irq_ctx.irq < 0)
 224                 return irq_ctx.irq;
 225
 226         if (wake_capable)
 227                 *wake_capable = irq_ctx.wake_capable;
 228
 229         return irq_ctx.irq;
 230 }
 231
 232 static int i2c_acpi_get_info(struct acpi_device *adev,
 233                              struct i2c_board_info *info,
 234                              struct i2c_adapter *adapter,
 235                              acpi_handle *adapter_handle)
 236 {
 237         struct i2c_acpi_lookup lookup;
 238         int ret;
 239
 240         memset(&lookup, 0, sizeof(lookup));
 241         lookup.info = info;
 242         lookup.index = -1;
 243
 244         if (acpi_device_enumerated(adev))
 245                 return -EINVAL;
 246
 247         ret = i2c_acpi_do_lookup(adev, &lookup);
 248         if (ret)
 249                 return ret;
 250
 251         if (adapter) {
 252                 /* The adapter must match the one in I2cSerialBus() connector */
 253                 if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
 254                         return -ENODEV;
 255         } else {
 256                 struct acpi_device *adapter_adev;
 257
 258                 /* The adapter must be present */
 259                 adapter_adev = acpi_fetch_acpi_dev(lookup.adapter_handle);
 260                 if (!adapter_adev)
 261                         return -ENODEV;
 262                 if (acpi_bus_get_status(adapter_adev) ||
 263                     !adapter_adev->status.present)
 264                         return -ENODEV;
 265         }
 266
 267         info->fwnode = acpi_fwnode_handle(adev);
 268         if (adapter_handle)
 269                 *adapter_handle = lookup.adapter_handle;
 270
 271         acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
 272                           sizeof(info->type));
 273
 274         return 0;
 275 }
 276
 277 static void i2c_acpi_register_device(struct i2c_adapter *adapter,
 278                                      struct acpi_device *adev,
 279                                      struct i2c_board_info *info)
 280 {
 281         /*
 282          * Skip registration on boards where the ACPI tables are
 283          * known to contain bogus I2C devices.
 284          */
 285         if (acpi_quirk_skip_i2c_client_enumeration(adev))
 286                 return;
 287
 288         adev->power.flags.ignore_parent = true;
 289         acpi_device_set_enumerated(adev);
 290
 291         if (IS_ERR(i2c_new_client_device(adapter, info)))
 292                 adev->power.flags.ignore_parent = false;
 293 }
 294
 295 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
 296                                        void *data, void **return_value)
 297 {
 298         struct i2c_adapter *adapter = data;
 299         struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 300         struct i2c_board_info info;
 301
 302         if (!adev || i2c_acpi_get_info(adev, &info, adapter, NULL))
 303                 return AE_OK;
 304
 305         i2c_acpi_register_device(adapter, adev, &info);
 306
 307         return AE_OK;
 308 }
 309
 310 #define I2C_ACPI_MAX_SCAN_DEPTH 32
 311
 312 /**
 313  * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
 314  * @adap: pointer to adapter
 315  *
 316  * Enumerate all I2C slave devices behind this adapter by walking the ACPI
 317  * namespace. When a device is found it will be added to the Linux device
 318  * model and bound to the corresponding ACPI handle.
 319  */
 320 void i2c_acpi_register_devices(struct i2c_adapter *adap)
 321 {
 322         struct acpi_device *adev;
 323         acpi_status status;
 324
 325         if (!has_acpi_companion(&adap->dev))
 326                 return;
 327
 328         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 329                                      I2C_ACPI_MAX_SCAN_DEPTH,
 330                                      i2c_acpi_add_device, NULL,
 331                                      adap, NULL);
 332         if (ACPI_FAILURE(status))
 333                 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
 334
 335         if (!adap->dev.parent)
 336                 return;
 337
 338         adev = ACPI_COMPANION(adap->dev.parent);
 339         if (!adev)
 340                 return;
 341
 342         acpi_dev_clear_dependencies(adev);
 343 }
 344
 345 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
 346         /*
 347          * These Silead touchscreen controllers only work at 400KHz, for
 348          * some reason they do not work at 100KHz. On some devices the ACPI
 349          * tables list another device at their bus as only being capable
 350          * of 100KHz, testing has shown that these other devices work fine
 351          * at 400KHz (as can be expected of any recent i2c hw) so we force
 352          * the speed of the bus to 400 KHz if a Silead device is present.
 353          */
 354         { "MSSL1680", 0 },
 355         {}
 356 };
 357
 358 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
 359                                            void *data, void **return_value)
 360 {
 361         struct i2c_acpi_lookup *lookup = data;
 362         struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 363
 364         if (!adev || i2c_acpi_do_lookup(adev, lookup))
 365                 return AE_OK;
 366
 367         if (lookup->search_handle != lookup->adapter_handle)
 368                 return AE_OK;
 369
 370         if (lookup->speed <= lookup->min_speed)
 371                 lookup->min_speed = lookup->speed;
 372
 373         if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
 374                 lookup->force_speed = I2C_MAX_FAST_MODE_FREQ;
 375
 376         return AE_OK;
 377 }
 378
 379 /**
 380  * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
 381  * @dev: The device owning the bus
 382  *
 383  * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
 384  * devices connected to this bus and use the speed of slowest device.
 385  *
 386  * Returns the speed in Hz or zero
 387  */
 388 u32 i2c_acpi_find_bus_speed(struct device *dev)
 389 {
 390         struct i2c_acpi_lookup lookup;
 391         struct i2c_board_info dummy;
 392         acpi_status status;
 393
 394         if (!has_acpi_companion(dev))
 395                 return 0;
 396
 397         memset(&lookup, 0, sizeof(lookup));
 398         lookup.search_handle = ACPI_HANDLE(dev);
 399         lookup.min_speed = UINT_MAX;
 400         lookup.info = &dummy;
 401         lookup.index = -1;
 402
 403         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 404                                      I2C_ACPI_MAX_SCAN_DEPTH,
 405                                      i2c_acpi_lookup_speed, NULL,
 406                                      &lookup, NULL);
 407
 408         if (ACPI_FAILURE(status)) {
 409                 dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
 410                 return 0;
 411         }
 412
 413         if (lookup.force_speed) {
 414                 if (lookup.force_speed != lookup.min_speed)
 415                         dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
 416                                  lookup.min_speed, lookup.force_speed);
 417                 return lookup.force_speed;
 418         } else if (lookup.min_speed != UINT_MAX) {
 419                 return lookup.min_speed;
 420         } else {
 421                 return 0;
 422         }
 423 }
 424 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
 425
 426 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 427 {
 428         struct i2c_adapter *adapter;
 429         struct device *dev;
 430
 431         dev = bus_find_device(&i2c_bus_type, NULL, handle, device_match_acpi_handle);
 432         if (!dev)
 433                 return NULL;
 434
 435         adapter = i2c_verify_adapter(dev);
 436         if (!adapter)
 437                 put_device(dev);
 438
 439         return adapter;
 440 }
 441 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 442
 443 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 444 {
 445         return i2c_find_device_by_fwnode(acpi_fwnode_handle(adev));
 446 }
 447
 448 static struct i2c_adapter *i2c_acpi_find_adapter_by_adev(struct acpi_device *adev)
 449 {
 450         return i2c_find_adapter_by_fwnode(acpi_fwnode_handle(adev));
 451 }
 452
 453 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
 454                            void *arg)
 455 {
 456         struct acpi_device *adev = arg;
 457         struct i2c_board_info info;
 458         acpi_handle adapter_handle;
 459         struct i2c_adapter *adapter;
 460         struct i2c_client *client;
 461
 462         switch (value) {
 463         case ACPI_RECONFIG_DEVICE_ADD:
 464                 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
 465                         break;
 466
 467                 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
 468                 if (!adapter)
 469                         break;
 470
 471                 i2c_acpi_register_device(adapter, adev, &info);
 472                 put_device(&adapter->dev);
 473                 break;
 474         case ACPI_RECONFIG_DEVICE_REMOVE:
 475                 if (!acpi_device_enumerated(adev))
 476                         break;
 477
 478                 client = i2c_acpi_find_client_by_adev(adev);
 479                 if (client) {
 480                         i2c_unregister_device(client);
 481                         put_device(&client->dev);
 482                 }
 483
 484                 adapter = i2c_acpi_find_adapter_by_adev(adev);
 485                 if (adapter) {
 486                         acpi_unbind_one(&adapter->dev);
 487                         put_device(&adapter->dev);
 488                 }
 489
 490                 break;
 491         }
 492
 493         return NOTIFY_OK;
 494 }
 495
 496 struct notifier_block i2c_acpi_notifier = {
 497         .notifier_call = i2c_acpi_notify,
 498 };
 499
 500 /**
 501  * i2c_acpi_new_device_by_fwnode - Create i2c-client for the Nth I2cSerialBus resource
 502  * @fwnode:  fwnode with the ACPI resources to get the client from
 503  * @index:   Index of ACPI resource to get
 504  * @info:    describes the I2C device; note this is modified (addr gets set)
 505  * Context: can sleep
 506  *
 507  * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
 508  * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
 509  * resources, in that case this function can be used to create an i2c-client
 510  * for other I2cSerialBus resources in the Current Resource Settings table.
 511  *
 512  * Also see i2c_new_client_device, which this function calls to create the
 513  * i2c-client.
 514  *
 515  * Returns a pointer to the new i2c-client, or error pointer in case of failure.
 516  * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
 517  */
 518 struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
 519                                                  int index,
 520                                                  struct i2c_board_info *info)
 521 {
 522         struct i2c_acpi_lookup lookup;
 523         struct i2c_adapter *adapter;
 524         struct acpi_device *adev;
 525         LIST_HEAD(resource_list);
 526         int ret;
 527
 528         adev = to_acpi_device_node(fwnode);
 529         if (!adev)
 530                 return ERR_PTR(-ENODEV);
 531
 532         memset(&lookup, 0, sizeof(lookup));
 533         lookup.info = info;
 534         lookup.device_handle = acpi_device_handle(adev);
 535         lookup.index = index;
 536
 537         ret = acpi_dev_get_resources(adev, &resource_list,
 538                                      i2c_acpi_fill_info, &lookup);
 539         if (ret < 0)
 540                 return ERR_PTR(ret);
 541
 542         acpi_dev_free_resource_list(&resource_list);
 543
 544         if (!info->addr)
 545                 return ERR_PTR(-EADDRNOTAVAIL);
 546
 547         adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
 548         if (!adapter)
 549                 return ERR_PTR(-EPROBE_DEFER);
 550
 551         return i2c_new_client_device(adapter, info);
 552 }
 553 EXPORT_SYMBOL_GPL(i2c_acpi_new_device_by_fwnode);
 554
 555 bool i2c_acpi_waive_d0_probe(struct device *dev)
 556 {
 557         struct i2c_driver *driver = to_i2c_driver(dev->driver);
 558         struct acpi_device *adev = ACPI_COMPANION(dev);
 559
 560         return driver->flags & I2C_DRV_ACPI_WAIVE_D0_PROBE &&
 561                 adev && adev->power.state_for_enumeration >= adev->power.state;
 562 }
 563 EXPORT_SYMBOL_GPL(i2c_acpi_waive_d0_probe);
 564
 565 #ifdef CONFIG_ACPI_I2C_OPREGION
 566 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
 567                 u8 cmd, u8 *data, u8 data_len)
 568 {
 569
 570         struct i2c_msg msgs[2];
 571         int ret;
 572         u8 *buffer;
 573
 574         buffer = kzalloc(data_len, GFP_KERNEL);
 575         if (!buffer)
 576                 return AE_NO_MEMORY;
 577
 578         msgs[0].addr = client->addr;
 579         msgs[0].flags = client->flags;
 580         msgs[0].len = 1;
 581         msgs[0].buf = &cmd;
 582
 583         msgs[1].addr = client->addr;
 584         msgs[1].flags = client->flags | I2C_M_RD;
 585         msgs[1].len = data_len;
 586         msgs[1].buf = buffer;
 587
 588         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 589         if (ret < 0) {
 590                 /* Getting a NACK is unfortunately normal with some DSTDs */
 591                 if (ret == -EREMOTEIO)
 592                         dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 593                                 data_len, client->addr, cmd, ret);
 594                 else
 595                         dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 596                                 data_len, client->addr, cmd, ret);
 597         /* 2 transfers must have completed successfully */
 598         } else if (ret == 2) {
 599                 memcpy(data, buffer, data_len);
 600                 ret = 0;
 601         } else {
 602                 ret = -EIO;
 603         }
 604
 605         kfree(buffer);
 606         return ret;
 607 }
 608
 609 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
 610                 u8 cmd, u8 *data, u8 data_len)
 611 {
 612
 613         struct i2c_msg msgs[1];
 614         u8 *buffer;
 615         int ret = AE_OK;
 616
 617         buffer = kzalloc(data_len + 1, GFP_KERNEL);
 618         if (!buffer)
 619                 return AE_NO_MEMORY;
 620
 621         buffer[0] = cmd;
 622         memcpy(buffer + 1, data, data_len);
 623
 624         msgs[0].addr = client->addr;
 625         msgs[0].flags = client->flags;
 626         msgs[0].len = data_len + 1;
 627         msgs[0].buf = buffer;
 628
 629         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 630
 631         kfree(buffer);
 632
 633         if (ret < 0) {
 634                 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
 635                 return ret;
 636         }
 637
 638         /* 1 transfer must have completed successfully */
 639         return (ret == 1) ? 0 : -EIO;
 640 }
 641
 642 static acpi_status
 643 i2c_acpi_space_handler(u32 function, acpi_physical_address command,
 644                         u32 bits, u64 *value64,
 645                         void *handler_context, void *region_context)
 646 {
 647         struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
 648         struct i2c_acpi_handler_data *data = handler_context;
 649         struct acpi_connection_info *info = &data->info;
 650         struct acpi_resource_i2c_serialbus *sb;
 651         struct i2c_adapter *adapter = data->adapter;
 652         struct i2c_client *client;
 653         struct acpi_resource *ares;
 654         u32 accessor_type = function >> 16;
 655         u8 action = function & ACPI_IO_MASK;
 656         acpi_status ret;
 657         int status;
 658
 659         ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
 660         if (ACPI_FAILURE(ret))
 661                 return ret;
 662
 663         client = kzalloc(sizeof(*client), GFP_KERNEL);
 664         if (!client) {
 665                 ret = AE_NO_MEMORY;
 666                 goto err;
 667         }
 668
 669         if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
 670                 ret = AE_BAD_PARAMETER;
 671                 goto err;
 672         }
 673
 674         client->adapter = adapter;
 675         client->addr = sb->slave_address;
 676
 677         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
 678                 client->flags |= I2C_CLIENT_TEN;
 679
 680         switch (accessor_type) {
 681         case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
 682                 if (action == ACPI_READ) {
 683                         status = i2c_smbus_read_byte(client);
 684                         if (status >= 0) {
 685                                 gsb->bdata = status;
 686                                 status = 0;
 687                         }
 688                 } else {
 689                         status = i2c_smbus_write_byte(client, gsb->bdata);
 690                 }
 691                 break;
 692
 693         case ACPI_GSB_ACCESS_ATTRIB_BYTE:
 694                 if (action == ACPI_READ) {
 695                         status = i2c_smbus_read_byte_data(client, command);
 696                         if (status >= 0) {
 697                                 gsb->bdata = status;
 698                                 status = 0;
 699                         }
 700                 } else {
 701                         status = i2c_smbus_write_byte_data(client, command,
 702                                         gsb->bdata);
 703                 }
 704                 break;
 705
 706         case ACPI_GSB_ACCESS_ATTRIB_WORD:
 707                 if (action == ACPI_READ) {
 708                         status = i2c_smbus_read_word_data(client, command);
 709                         if (status >= 0) {
 710                                 gsb->wdata = status;
 711                                 status = 0;
 712                         }
 713                 } else {
 714                         status = i2c_smbus_write_word_data(client, command,
 715                                         gsb->wdata);
 716                 }
 717                 break;
 718
 719         case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
 720                 if (action == ACPI_READ) {
 721                         status = i2c_smbus_read_block_data(client, command,
 722                                         gsb->data);
 723                         if (status >= 0) {
 724                                 gsb->len = status;
 725                                 status = 0;
 726                         }
 727                 } else {
 728                         status = i2c_smbus_write_block_data(client, command,
 729                                         gsb->len, gsb->data);
 730                 }
 731                 break;
 732
 733         case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
 734                 if (action == ACPI_READ) {
 735                         status = acpi_gsb_i2c_read_bytes(client, command,
 736                                         gsb->data, info->access_length);
 737                 } else {
 738                         status = acpi_gsb_i2c_write_bytes(client, command,
 739                                         gsb->data, info->access_length);
 740                 }
 741                 break;
 742
 743         default:
 744                 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
 745                          accessor_type, client->addr);
 746                 ret = AE_BAD_PARAMETER;
 747                 goto err;
 748         }
 749
 750         gsb->status = status;
 751
 752  err:
 753         kfree(client);
 754         ACPI_FREE(ares);
 755         return ret;
 756 }
 757
 758
 759 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
 760 {
 761         acpi_handle handle;
 762         struct i2c_acpi_handler_data *data;
 763         acpi_status status;
 764
 765         if (!adapter->dev.parent)
 766                 return -ENODEV;
 767
 768         handle = ACPI_HANDLE(adapter->dev.parent);
 769
 770         if (!handle)
 771                 return -ENODEV;
 772
 773         data = kzalloc(sizeof(struct i2c_acpi_handler_data),
 774                             GFP_KERNEL);
 775         if (!data)
 776                 return -ENOMEM;
 777
 778         data->adapter = adapter;
 779         status = acpi_bus_attach_private_data(handle, (void *)data);
 780         if (ACPI_FAILURE(status)) {
 781                 kfree(data);
 782                 return -ENOMEM;
 783         }
 784
 785         status = acpi_install_address_space_handler(handle,
 786                                 ACPI_ADR_SPACE_GSBUS,
 787                                 &i2c_acpi_space_handler,
 788                                 NULL,
 789                                 data);
 790         if (ACPI_FAILURE(status)) {
 791                 dev_err(&adapter->dev, "Error installing i2c space handler\n");
 792                 acpi_bus_detach_private_data(handle);
 793                 kfree(data);
 794                 return -ENOMEM;
 795         }
 796
 797         return 0;
 798 }
 799
 800 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
 801 {
 802         acpi_handle handle;
 803         struct i2c_acpi_handler_data *data;
 804         acpi_status status;
 805
 806         if (!adapter->dev.parent)
 807                 return;
 808
 809         handle = ACPI_HANDLE(adapter->dev.parent);
 810
 811         if (!handle)
 812                 return;
 813
 814         acpi_remove_address_space_handler(handle,
 815                                 ACPI_ADR_SPACE_GSBUS,
 816                                 &i2c_acpi_space_handler);
 817
 818         status = acpi_bus_get_private_data(handle, (void **)&data);
 819         if (ACPI_SUCCESS(status))
 820                 kfree(data);
 821
 822         acpi_bus_detach_private_data(handle);
 823 }
 824 #endif /* CONFIG_ACPI_I2C_OPREGION */