MdeModulePkg/Bus/I2c/I2cDxe/I2cHost.c

   1 /** @file
   2   This file implements I2C Host Protocol which provides callers with the ability to
   3   do I/O transactions to all of the devices on the I2C bus.
   4
   5   Copyright (c) 2014, Hewlett-Packard Development Company, L.P.<BR>
   6   Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8
   9 **/
  10
  11 #include "I2cDxe.h"
  12
  13 EFI_DRIVER_BINDING_PROTOCOL  gI2cHostDriverBinding = {
  14   I2cHostDriverSupported,
  15   I2cHostDriverStart,
  16   I2cHostDriverStop,
  17   0x10,
  18   NULL,
  19   NULL
  20 };
  21
  22 //
  23 // Driver name table
  24 //
  25 GLOBAL_REMOVE_IF_UNREFERENCED EFI_UNICODE_STRING_TABLE  mI2cHostDriverNameTable[] = {
  26   { "eng;en", L"I2c Host Driver" },
  27   { NULL,     NULL               }
  28 };
  29
  30 //
  31 // EFI Component Name Protocol
  32 //
  33 GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME_PROTOCOL  gI2cHostComponentName = {
  34   (EFI_COMPONENT_NAME_GET_DRIVER_NAME)I2cHostComponentNameGetDriverName,
  35   (EFI_COMPONENT_NAME_GET_CONTROLLER_NAME)I2cHostComponentNameGetControllerName,
  36   "eng"
  37 };
  38
  39 //
  40 // EFI Component Name 2 Protocol
  41 //
  42 GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME2_PROTOCOL  gI2cHostComponentName2 = {
  43   I2cHostComponentNameGetDriverName,
  44   I2cHostComponentNameGetControllerName,
  45   "en"
  46 };
  47
  48 /**
  49   Retrieves a Unicode string that is the user readable name of the driver.
  50
  51   This function retrieves the user readable name of a driver in the form of a
  52   Unicode string. If the driver specified by This has a user readable name in
  53   the language specified by Language, then a pointer to the driver name is
  54   returned in DriverName, and EFI_SUCCESS is returned. If the driver specified
  55   by This does not support the language specified by Language,
  56   then EFI_UNSUPPORTED is returned.
  57
  58   @param  This[in]              A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
  59                                 EFI_COMPONENT_NAME_PROTOCOL instance.
  60
  61   @param  Language[in]          A pointer to a Null-terminated ASCII string
  62                                 array indicating the language. This is the
  63                                 language of the driver name that the caller is
  64                                 requesting, and it must match one of the
  65                                 languages specified in SupportedLanguages. The
  66                                 number of languages supported by a driver is up
  67                                 to the driver writer. Language is specified
  68                                 in RFC 4646 or ISO 639-2 language code format.
  69
  70   @param  DriverName[out]       A pointer to the Unicode string to return.
  71                                 This Unicode string is the name of the
  72                                 driver specified by This in the language
  73                                 specified by Language.
  74
  75   @retval EFI_SUCCESS           The Unicode string for the Driver specified by
  76                                 This and the language specified by Language was
  77                                 returned in DriverName.
  78
  79   @retval EFI_INVALID_PARAMETER Language is NULL.
  80
  81   @retval EFI_INVALID_PARAMETER DriverName is NULL.
  82
  83   @retval EFI_UNSUPPORTED       The driver specified by This does not support
  84                                 the language specified by Language.
  85
  86 **/
  87 EFI_STATUS
  88 EFIAPI
  89 I2cHostComponentNameGetDriverName (
  90   IN  EFI_COMPONENT_NAME2_PROTOCOL  *This,
  91   IN  CHAR8                         *Language,
  92   OUT CHAR16                        **DriverName
  93   )
  94 {
  95   return LookupUnicodeString2 (
  96            Language,
  97            This->SupportedLanguages,
  98            mI2cHostDriverNameTable,
  99            DriverName,
 100            (BOOLEAN)(This != &gI2cHostComponentName2)
 101            );
 102 }
 103
 104 /**
 105   Retrieves a Unicode string that is the user readable name of the controller
 106   that is being managed by a driver.
 107
 108   This function retrieves the user readable name of the controller specified by
 109   ControllerHandle and ChildHandle in the form of a Unicode string. If the
 110   driver specified by This has a user readable name in the language specified by
 111   Language, then a pointer to the controller name is returned in ControllerName,
 112   and EFI_SUCCESS is returned.  If the driver specified by This is not currently
 113   managing the controller specified by ControllerHandle and ChildHandle,
 114   then EFI_UNSUPPORTED is returned.  If the driver specified by This does not
 115   support the language specified by Language, then EFI_UNSUPPORTED is returned.
 116
 117   @param  This[in]              A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
 118                                 EFI_COMPONENT_NAME_PROTOCOL instance.
 119
 120   @param  ControllerHandle[in]  The handle of a controller that the driver
 121                                 specified by This is managing.  This handle
 122                                 specifies the controller whose name is to be
 123                                 returned.
 124
 125   @param  ChildHandle[in]       The handle of the child controller to retrieve
 126                                 the name of.  This is an optional parameter that
 127                                 may be NULL.  It will be NULL for device
 128                                 drivers.  It will also be NULL for a bus drivers
 129                                 that wish to retrieve the name of the bus
 130                                 controller.  It will not be NULL for a bus
 131                                 driver that wishes to retrieve the name of a
 132                                 child controller.
 133
 134   @param  Language[in]          A pointer to a Null-terminated ASCII string
 135                                 array indicating the language.  This is the
 136                                 language of the driver name that the caller is
 137                                 requesting, and it must match one of the
 138                                 languages specified in SupportedLanguages. The
 139                                 number of languages supported by a driver is up
 140                                 to the driver writer. Language is specified in
 141                                 RFC 4646 or ISO 639-2 language code format.
 142
 143   @param  ControllerName[out]   A pointer to the Unicode string to return.
 144                                 This Unicode string is the name of the
 145                                 controller specified by ControllerHandle and
 146                                 ChildHandle in the language specified by
 147                                 Language from the point of view of the driver
 148                                 specified by This.
 149
 150   @retval EFI_SUCCESS           The Unicode string for the user readable name in
 151                                 the language specified by Language for the
 152                                 driver specified by This was returned in
 153                                 DriverName.
 154
 155   @retval EFI_INVALID_PARAMETER ControllerHandle is NULL.
 156
 157   @retval EFI_INVALID_PARAMETER ChildHandle is not NULL and it is not a valid
 158                                 EFI_HANDLE.
 159
 160   @retval EFI_INVALID_PARAMETER Language is NULL.
 161
 162   @retval EFI_INVALID_PARAMETER ControllerName is NULL.
 163
 164   @retval EFI_UNSUPPORTED       The driver specified by This is not currently
 165                                 managing the controller specified by
 166                                 ControllerHandle and ChildHandle.
 167
 168   @retval EFI_UNSUPPORTED       The driver specified by This does not support
 169                                 the language specified by Language.
 170
 171 **/
 172 EFI_STATUS
 173 EFIAPI
 174 I2cHostComponentNameGetControllerName (
 175   IN  EFI_COMPONENT_NAME2_PROTOCOL  *This,
 176   IN  EFI_HANDLE                    ControllerHandle,
 177   IN  EFI_HANDLE                    ChildHandle        OPTIONAL,
 178   IN  CHAR8                         *Language,
 179   OUT CHAR16                        **ControllerName
 180   )
 181 {
 182   return EFI_UNSUPPORTED;
 183 }
 184
 185 /**
 186   Tests to see if this driver supports a given controller. If a child device is provided,
 187   it further tests to see if this driver supports creating a handle for the specified child device.
 188
 189   This function checks to see if the driver specified by This supports the device specified by
 190   ControllerHandle. Drivers will typically use the device path attached to
 191   ControllerHandle and/or the services from the bus I/O abstraction attached to
 192   ControllerHandle to determine if the driver supports ControllerHandle. This function
 193   may be called many times during platform initialization. In order to reduce boot times, the tests
 194   performed by this function must be very small, and take as little time as possible to execute. This
 195   function must not change the state of any hardware devices, and this function must be aware that the
 196   device specified by ControllerHandle may already be managed by the same driver or a
 197   different driver. This function must match its calls to AllocatePages() with FreePages(),
 198   AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().
 199   Since ControllerHandle may have been previously started by the same driver, if a protocol is
 200   already in the opened state, then it must not be closed with CloseProtocol(). This is required
 201   to guarantee the state of ControllerHandle is not modified by this function.
 202
 203   @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
 204   @param[in]  ControllerHandle     The handle of the controller to test. This handle
 205                                    must support a protocol interface that supplies
 206                                    an I/O abstraction to the driver.
 207   @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This
 208                                    parameter is ignored by device drivers, and is optional for bus
 209                                    drivers. For bus drivers, if this parameter is not NULL, then
 210                                    the bus driver must determine if the bus controller specified
 211                                    by ControllerHandle and the child controller specified
 212                                    by RemainingDevicePath are both supported by this
 213                                    bus driver.
 214
 215   @retval EFI_SUCCESS              The device specified by ControllerHandle and
 216                                    RemainingDevicePath is supported by the driver specified by This.
 217   @retval EFI_ALREADY_STARTED      The device specified by ControllerHandle and
 218                                    RemainingDevicePath is already being managed by the driver
 219                                    specified by This.
 220   @retval EFI_ACCESS_DENIED        The device specified by ControllerHandle and
 221                                    RemainingDevicePath is already being managed by a different
 222                                    driver or an application that requires exclusive access.
 223                                    Currently not implemented.
 224   @retval EFI_UNSUPPORTED          The device specified by ControllerHandle and
 225                                    RemainingDevicePath is not supported by the driver specified by This.
 226 **/
 227 EFI_STATUS
 228 EFIAPI
 229 I2cHostDriverSupported (
 230   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
 231   IN EFI_HANDLE                   Controller,
 232   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
 233   )
 234 {
 235   EFI_I2C_MASTER_PROTOCOL                        *I2cMaster;
 236   EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL  *I2cBusConfigurationManagement;
 237   EFI_STATUS                                     Status;
 238
 239   //
 240   //  Locate I2C Bus Configuration Management Protocol
 241   //
 242   Status = gBS->OpenProtocol (
 243                   Controller,
 244                   &gEfiI2cBusConfigurationManagementProtocolGuid,
 245                   (VOID **)&I2cBusConfigurationManagement,
 246                   This->DriverBindingHandle,
 247                   Controller,
 248                   EFI_OPEN_PROTOCOL_BY_DRIVER
 249                   );
 250   if (EFI_ERROR (Status)) {
 251     return Status;
 252   }
 253
 254   //
 255   // Close the protocol because we don't use it here
 256   //
 257   gBS->CloseProtocol (
 258          Controller,
 259          &gEfiI2cBusConfigurationManagementProtocolGuid,
 260          This->DriverBindingHandle,
 261          Controller
 262          );
 263
 264   //
 265   //  Locate I2C Master Protocol
 266   //
 267   Status = gBS->OpenProtocol (
 268                   Controller,
 269                   &gEfiI2cMasterProtocolGuid,
 270                   (VOID **)&I2cMaster,
 271                   This->DriverBindingHandle,
 272                   Controller,
 273                   EFI_OPEN_PROTOCOL_GET_PROTOCOL
 274                   );
 275   if (EFI_ERROR (Status)) {
 276     return Status;
 277   }
 278
 279   return EFI_SUCCESS;
 280 }
 281
 282 /**
 283   Starts a device controller or a bus controller.
 284
 285   The Start() function is designed to be invoked from the EFI boot service ConnectController().
 286   As a result, much of the error checking on the parameters to Start() has been moved into this
 287   common boot service. It is legal to call Start() from other locations,
 288   but the following calling restrictions must be followed, or the system behavior will not be deterministic.
 289   1. ControllerHandle must be a valid EFI_HANDLE.
 290   2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
 291      EFI_DEVICE_PATH_PROTOCOL.
 292   3. Prior to calling Start(), the Supported() function for the driver specified by This must
 293      have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.
 294
 295   @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
 296   @param[in]  ControllerHandle     The handle of the controller to start. This handle
 297                                    must support a protocol interface that supplies
 298                                    an I/O abstraction to the driver.
 299   @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This
 300                                    parameter is ignored by device drivers, and is optional for bus
 301                                    drivers. For a bus driver, if this parameter is NULL, then handles
 302                                    for all the children of Controller are created by this driver.
 303                                    If this parameter is not NULL and the first Device Path Node is
 304                                    not the End of Device Path Node, then only the handle for the
 305                                    child device specified by the first Device Path Node of
 306                                    RemainingDevicePath is created by this driver.
 307                                    If the first Device Path Node of RemainingDevicePath is
 308                                    the End of Device Path Node, no child handle is created by this
 309                                    driver.
 310
 311   @retval EFI_SUCCESS              The device was started.
 312   @retval EFI_DEVICE_ERROR         The device could not be started due to a device error.Currently not implemented.
 313   @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.
 314   @retval Others                   The driver failed to start the device.
 315
 316 **/
 317 EFI_STATUS
 318 EFIAPI
 319 I2cHostDriverStart (
 320   IN EFI_DRIVER_BINDING_PROTOCOL  *This,
 321   IN EFI_HANDLE                   Controller,
 322   IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
 323   )
 324 {
 325   EFI_STATUS                                     Status;
 326   EFI_I2C_MASTER_PROTOCOL                        *I2cMaster;
 327   EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL  *I2cBusConfigurationManagement;
 328   I2C_HOST_CONTEXT                               *I2cHostContext;
 329
 330   I2cMaster                     = NULL;
 331   I2cHostContext                = NULL;
 332   I2cBusConfigurationManagement = NULL;
 333
 334   //
 335   // Locate I2C Bus Configuration Management Protocol
 336   //
 337   Status = gBS->OpenProtocol (
 338                   Controller,
 339                   &gEfiI2cBusConfigurationManagementProtocolGuid,
 340                   (VOID **)&I2cBusConfigurationManagement,
 341                   This->DriverBindingHandle,
 342                   Controller,
 343                   EFI_OPEN_PROTOCOL_BY_DRIVER
 344                   );
 345   if (EFI_ERROR (Status)) {
 346     DEBUG ((DEBUG_ERROR, "I2cHost: Open I2C bus configuration error, Status = %r\n", Status));
 347     return Status;
 348   }
 349
 350   //
 351   // Locate I2C Master Protocol
 352   //
 353   Status = gBS->OpenProtocol (
 354                   Controller,
 355                   &gEfiI2cMasterProtocolGuid,
 356                   (VOID **)&I2cMaster,
 357                   This->DriverBindingHandle,
 358                   Controller,
 359                   EFI_OPEN_PROTOCOL_GET_PROTOCOL
 360                   );
 361   if (EFI_ERROR (Status)) {
 362     DEBUG ((DEBUG_ERROR, "I2cHost: Open I2C master error, Status = %r\n", Status));
 363     goto Exit;
 364   }
 365
 366   //
 367   // Allocate the I2C Host Context structure
 368   //
 369   I2cHostContext = AllocateZeroPool (sizeof (I2C_HOST_CONTEXT));
 370   if (I2cHostContext == NULL) {
 371     DEBUG ((DEBUG_ERROR, "I2cHost: there is no enough memory to allocate.\n"));
 372     Status = EFI_OUT_OF_RESOURCES;
 373     goto Exit;
 374   }
 375
 376   //
 377   // Initialize the context structure for the current I2C Controller
 378   //
 379   I2cHostContext->Signature                     = I2C_HOST_SIGNATURE;
 380   I2cHostContext->I2cMaster                     = I2cMaster;
 381   I2cHostContext->I2cBusConfigurationManagement = I2cBusConfigurationManagement;
 382   I2cHostContext->I2cBusConfiguration           = (UINTN)-1;
 383   InitializeListHead (&I2cHostContext->RequestList);
 384
 385   //
 386   // Reset the controller
 387   //
 388   Status = I2cMaster->Reset (I2cMaster);
 389   if (EFI_ERROR (Status)) {
 390     DEBUG ((DEBUG_ERROR, "I2cHost: I2C controller reset failed!\n"));
 391     goto Exit;
 392   }
 393
 394   //
 395   // Create the I2C transaction complete event
 396   //
 397   Status = gBS->CreateEvent (
 398                   EVT_NOTIFY_SIGNAL,
 399                   TPL_I2C_SYNC,
 400                   I2cHostRequestCompleteEvent,
 401                   I2cHostContext,
 402                   &I2cHostContext->I2cEvent
 403                   );
 404   if (EFI_ERROR (Status)) {
 405     DEBUG ((DEBUG_ERROR, "I2cHost: create complete event error, Status = %r\n", Status));
 406     goto Exit;
 407   }
 408
 409   //
 410   // Get the bus management event
 411   //
 412   Status = gBS->CreateEvent (
 413                   EVT_NOTIFY_SIGNAL,
 414                   TPL_I2C_SYNC,
 415                   I2cHostI2cBusConfigurationAvailable,
 416                   I2cHostContext,
 417                   &I2cHostContext->I2cBusConfigurationEvent
 418                   );
 419   if (EFI_ERROR (Status)) {
 420     DEBUG ((DEBUG_ERROR, "I2cHost: create bus available event error, Status = %r\n", Status));
 421     goto Exit;
 422   }
 423
 424   //
 425   // Build the I2C host protocol for the current I2C controller
 426   //
 427   I2cHostContext->I2cHost.QueueRequest              = I2cHostQueueRequest;
 428   I2cHostContext->I2cHost.I2cControllerCapabilities = I2cMaster->I2cControllerCapabilities;
 429
 430   //
 431   //  Install the driver protocol
 432   //
 433   Status = gBS->InstallMultipleProtocolInterfaces (
 434                   &Controller,
 435                   &gEfiI2cHostProtocolGuid,
 436                   &I2cHostContext->I2cHost,
 437                   NULL
 438                   );
 439 Exit:
 440   if (EFI_ERROR (Status)) {
 441     DEBUG ((DEBUG_ERROR, "I2cHost: Start() function failed, Status = %r\n", Status));
 442     if (I2cBusConfigurationManagement != NULL) {
 443       gBS->CloseProtocol (
 444              Controller,
 445              &gEfiI2cBusConfigurationManagementProtocolGuid,
 446              This->DriverBindingHandle,
 447              Controller
 448              );
 449     }
 450
 451     if ((I2cHostContext != NULL) && (I2cHostContext->I2cEvent != NULL)) {
 452       gBS->CloseEvent (I2cHostContext->I2cEvent);
 453       I2cHostContext->I2cEvent = NULL;
 454     }
 455
 456     if ((I2cHostContext != NULL) && (I2cHostContext->I2cBusConfigurationEvent != NULL)) {
 457       gBS->CloseEvent (I2cHostContext->I2cBusConfigurationEvent);
 458       I2cHostContext->I2cBusConfigurationEvent = NULL;
 459     }
 460
 461     //
 462     //  Release the context structure upon failure
 463     //
 464     if (I2cHostContext != NULL) {
 465       FreePool (I2cHostContext);
 466     }
 467   }
 468
 469   //
 470   //  Return the operation status.
 471   //
 472   return Status;
 473 }
 474
 475 /**
 476   Stops a device controller or a bus controller.
 477
 478   The Stop() function is designed to be invoked from the EFI boot service DisconnectController().
 479   As a result, much of the error checking on the parameters to Stop() has been moved
 480   into this common boot service. It is legal to call Stop() from other locations,
 481   but the following calling restrictions must be followed, or the system behavior will not be deterministic.
 482   1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
 483      same driver's Start() function.
 484   2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
 485      EFI_HANDLE. In addition, all of these handles must have been created in this driver's
 486      Start() function, and the Start() function must have called OpenProtocol() on
 487      ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
 488
 489   @param[in]  This              A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
 490   @param[in]  ControllerHandle  A handle to the device being stopped. The handle must
 491                                 support a bus specific I/O protocol for the driver
 492                                 to use to stop the device.
 493   @param[in]  NumberOfChildren  The number of child device handles in ChildHandleBuffer.
 494   @param[in]  ChildHandleBuffer An array of child handles to be freed. May be NULL
 495                                 if NumberOfChildren is 0.
 496
 497   @retval EFI_SUCCESS           The device was stopped.
 498   @retval EFI_DEVICE_ERROR      The device could not be stopped due to a device error.
 499
 500 **/
 501 EFI_STATUS
 502 EFIAPI
 503 I2cHostDriverStop (
 504   IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
 505   IN  EFI_HANDLE                   Controller,
 506   IN  UINTN                        NumberOfChildren,
 507   IN  EFI_HANDLE                   *ChildHandleBuffer
 508   )
 509 {
 510   EFI_STATUS             Status;
 511   I2C_HOST_CONTEXT       *I2cHostContext;
 512   EFI_I2C_HOST_PROTOCOL  *I2cHost;
 513   EFI_TPL                TplPrevious;
 514
 515   TplPrevious = EfiGetCurrentTpl ();
 516   if (TplPrevious > TPL_I2C_SYNC) {
 517     DEBUG ((DEBUG_ERROR, "I2cHost: TPL %d is too high in Stop.\n", TplPrevious));
 518     return EFI_DEVICE_ERROR;
 519   }
 520
 521   Status = gBS->OpenProtocol (
 522                   Controller,
 523                   &gEfiI2cHostProtocolGuid,
 524                   (VOID **)&I2cHost,
 525                   This->DriverBindingHandle,
 526                   Controller,
 527                   EFI_OPEN_PROTOCOL_GET_PROTOCOL
 528                   );
 529
 530   if (EFI_ERROR (Status)) {
 531     return EFI_DEVICE_ERROR;
 532   }
 533
 534   I2cHostContext = I2C_HOST_CONTEXT_FROM_PROTOCOL (I2cHost);
 535
 536   //
 537   // Raise TPL for critical section
 538   //
 539   TplPrevious = gBS->RaiseTPL (TPL_I2C_SYNC);
 540
 541   //
 542   // If there is pending request or pending bus configuration, do not stop
 543   //
 544   Status = EFI_DEVICE_ERROR;
 545   if (  (!I2cHostContext->I2cBusConfigurationManagementPending)
 546      && IsListEmpty (&I2cHostContext->RequestList))
 547   {
 548     //
 549     //  Remove the I2C host protocol
 550     //
 551     Status = gBS->UninstallMultipleProtocolInterfaces (
 552                     Controller,
 553                     &gEfiI2cHostProtocolGuid,
 554                     I2cHost,
 555                     NULL
 556                     );
 557   }
 558
 559   //
 560   // Leave critical section
 561   //
 562   gBS->RestoreTPL (TplPrevious);
 563   if (!EFI_ERROR (Status)) {
 564     gBS->CloseProtocol (
 565            Controller,
 566            &gEfiI2cBusConfigurationManagementProtocolGuid,
 567            This->DriverBindingHandle,
 568            Controller
 569            );
 570
 571     //
 572     // Release I2c Host resources
 573     //
 574     if (I2cHostContext->I2cBusConfigurationEvent != NULL) {
 575       gBS->CloseEvent (I2cHostContext->I2cBusConfigurationEvent);
 576       I2cHostContext->I2cBusConfigurationEvent = NULL;
 577     }
 578
 579     if (I2cHostContext->I2cEvent != NULL) {
 580       gBS->CloseEvent (I2cHostContext->I2cEvent);
 581       I2cHostContext->I2cEvent = NULL;
 582     }
 583
 584     FreePool (I2cHostContext);
 585   }
 586
 587   //
 588   //  Return the stop status
 589   //
 590   return Status;
 591 }
 592
 593 /**
 594   Handle the I2C bus configuration available event
 595
 596   This routine is called at TPL_I2C_SYNC.
 597
 598   @param[in] Event    Address of an EFI_EVENT handle
 599   @param[in] Context  Address of an I2C_HOST_CONTEXT structure
 600
 601 **/
 602 VOID
 603 EFIAPI
 604 I2cHostI2cBusConfigurationAvailable (
 605   IN EFI_EVENT  Event,
 606   IN VOID       *Context
 607   )
 608 {
 609   I2C_HOST_CONTEXT         *I2cHostContext;
 610   EFI_I2C_MASTER_PROTOCOL  *I2cMaster;
 611   I2C_REQUEST              *I2cRequest;
 612   LIST_ENTRY               *EntryHeader;
 613   LIST_ENTRY               *Entry;
 614   EFI_STATUS               Status;
 615
 616   //
 617   // Mark this I2C bus configuration management operation as complete
 618   //
 619   I2cHostContext = (I2C_HOST_CONTEXT *)Context;
 620   I2cMaster      = I2cHostContext->I2cMaster;
 621   ASSERT (I2cMaster != NULL);
 622   //
 623   // Clear flag to indicate I2C bus configuration is finished
 624   //
 625   I2cHostContext->I2cBusConfigurationManagementPending = FALSE;
 626
 627   //
 628   //  Validate the completion status
 629   //
 630   if (EFI_ERROR (I2cHostContext->Status)) {
 631     //
 632     // Setting I2C bus configuration failed before
 633     //
 634     I2cHostRequestComplete (I2cHostContext, I2cHostContext->Status);
 635
 636     //
 637     // Unknown I2C bus configuration
 638     // Force next operation to enable the I2C bus configuration
 639     //
 640     I2cHostContext->I2cBusConfiguration = (UINTN)-1;
 641
 642     //
 643     // Do not continue current I2C request
 644     //
 645     return;
 646   }
 647
 648   //
 649   // Get the first request in the link with FIFO order
 650   //
 651   EntryHeader = &I2cHostContext->RequestList;
 652   Entry       = GetFirstNode (EntryHeader);
 653   I2cRequest  = I2C_REQUEST_FROM_ENTRY (Entry);
 654
 655   //
 656   // Update the I2C bus configuration of the current I2C request
 657   //
 658   I2cHostContext->I2cBusConfiguration = I2cRequest->I2cBusConfiguration;
 659
 660   //
 661   // Start an I2C operation on the host, the status is returned by I2cHostContext->Status
 662   //
 663   Status = I2cMaster->StartRequest (
 664                         I2cMaster,
 665                         I2cRequest->SlaveAddress,
 666                         I2cRequest->RequestPacket,
 667                         I2cHostContext->I2cEvent,
 668                         &I2cHostContext->Status
 669                         );
 670
 671   if (EFI_ERROR (Status)) {
 672     DEBUG ((DEBUG_ERROR, "I2cHostI2cBusConfigurationAvailable: Error starting I2C operation, %r\n", Status));
 673   }
 674 }
 675
 676 /**
 677   Complete the current request
 678
 679   This routine is called at TPL_I2C_SYNC.
 680
 681   @param[in] I2cHostContext  Address of an I2C_HOST_CONTEXT structure.
 682   @param[in] Status          Status of the I2C operation.
 683
 684   @return This routine returns the input status value.
 685
 686 **/
 687 EFI_STATUS
 688 I2cHostRequestComplete (
 689   I2C_HOST_CONTEXT  *I2cHostContext,
 690   EFI_STATUS        Status
 691   )
 692 {
 693   I2C_REQUEST  *I2cRequest;
 694   LIST_ENTRY   *EntryHeader;
 695   LIST_ENTRY   *Entry;
 696
 697   //
 698   // Remove the current I2C request from the list
 699   //
 700   EntryHeader = &I2cHostContext->RequestList;
 701   Entry       = GetFirstNode (EntryHeader);
 702   I2cRequest  = I2C_REQUEST_FROM_ENTRY (Entry);
 703
 704   //
 705   // Save the status for QueueRequest
 706   //
 707   if ( NULL != I2cRequest->Status ) {
 708     *I2cRequest->Status = Status;
 709   }
 710
 711   //
 712   //  Notify the user of the I2C request completion
 713   //
 714   if ( NULL != I2cRequest->Event ) {
 715     gBS->SignalEvent (I2cRequest->Event);
 716   }
 717
 718   //
 719   // Done with this request, remove the current request from list
 720   //
 721   RemoveEntryList (&I2cRequest->Link);
 722   FreePool (I2cRequest->RequestPacket);
 723   FreePool (I2cRequest);
 724
 725   //
 726   // If there is more I2C request, start next one
 727   //
 728   if (!IsListEmpty (EntryHeader)) {
 729     I2cHostRequestEnable (I2cHostContext);
 730   }
 731
 732   return Status;
 733 }
 734
 735 /**
 736   Handle the bus available event
 737
 738   This routine is called at TPL_I2C_SYNC.
 739
 740   @param[in] Event    Address of an EFI_EVENT handle
 741   @param[in] Context  Address of an I2C_HOST_CONTEXT structure
 742
 743 **/
 744 VOID
 745 EFIAPI
 746 I2cHostRequestCompleteEvent (
 747   IN EFI_EVENT  Event,
 748   IN VOID       *Context
 749   )
 750 {
 751   I2C_HOST_CONTEXT  *I2cHostContext;
 752
 753   //
 754   // Handle the completion event
 755   //
 756   I2cHostContext = (I2C_HOST_CONTEXT *)Context;
 757   I2cHostRequestComplete (I2cHostContext, I2cHostContext->Status);
 758 }
 759
 760 /**
 761   Enable access to the I2C bus configuration
 762
 763   @param[in] I2cHostContext     Address of an I2C_HOST_CONTEXT structure
 764
 765   @retval EFI_SUCCESS           The operation completed successfully.
 766   @retval EFI_ABORTED           The request did not complete because the driver
 767                                 was shutdown.
 768   @retval EFI_BAD_BUFFER_SIZE   The WriteBytes or ReadBytes buffer size is too large.
 769   @retval EFI_DEVICE_ERROR      There was an I2C error (NACK) during the operation.
 770                                 This could indicate the slave device is not present.
 771   @retval EFI_INVALID_PARAMETER RequestPacket is NULL
 772   @retval EFI_NO_MAPPING        Invalid I2cBusConfiguration value
 773   @retval EFI_NO_RESPONSE       The I2C device is not responding to the
 774                                 slave address.  EFI_DEVICE_ERROR may also be
 775                                 returned if the controller can not distinguish
 776                                 when the NACK occurred.
 777   @retval EFI_NOT_FOUND         I2C slave address exceeds maximum address
 778   @retval EFI_NOT_READY         I2C bus is busy or operation pending, wait for
 779                                 the event and then read status.
 780   @retval EFI_OUT_OF_RESOURCES  Insufficient memory for I2C operation
 781   @retval EFI_TIMEOUT           The transaction did not complete within an internally
 782                                 specified timeout period.
 783
 784 **/
 785 EFI_STATUS
 786 I2cHostRequestEnable (
 787   I2C_HOST_CONTEXT  *I2cHostContext
 788   )
 789 {
 790   UINTN                                                I2cBusConfiguration;
 791   CONST EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL  *I2cBusConfigurationManagement;
 792   I2C_REQUEST                                          *I2cRequest;
 793   EFI_STATUS                                           Status;
 794   EFI_TPL                                              TplPrevious;
 795   LIST_ENTRY                                           *EntryHeader;
 796   LIST_ENTRY                                           *Entry;
 797
 798   //
 799   //  Assume pending request
 800   //
 801   Status = EFI_NOT_READY;
 802
 803   I2cBusConfigurationManagement = I2cHostContext->I2cBusConfigurationManagement;
 804
 805   //
 806   //  Validate the I2c bus configuration
 807   //
 808   EntryHeader = &I2cHostContext->RequestList;
 809   Entry       = GetFirstNode (EntryHeader);
 810   I2cRequest  = I2C_REQUEST_FROM_ENTRY (Entry);
 811
 812   I2cBusConfiguration = I2cRequest->I2cBusConfiguration;
 813
 814   if (I2cHostContext->I2cBusConfiguration != I2cBusConfiguration ) {
 815     //
 816     // Set flag to indicate I2C bus configuration is in progress
 817     //
 818     I2cHostContext->I2cBusConfigurationManagementPending = TRUE;
 819     //
 820     //  Update bus configuration for this device's requesting bus configuration
 821     //
 822     Status = I2cBusConfigurationManagement->EnableI2cBusConfiguration (
 823                                               I2cBusConfigurationManagement,
 824                                               I2cBusConfiguration,
 825                                               I2cHostContext->I2cBusConfigurationEvent,
 826                                               &I2cHostContext->Status
 827                                               );
 828   } else {
 829     //
 830     //  I2C bus configuration is same, no need change configuration and start I2c transaction directly
 831     //
 832     TplPrevious = gBS->RaiseTPL (TPL_I2C_SYNC);
 833
 834     //
 835     //  Same I2C bus configuration
 836     //
 837     I2cHostContext->Status = EFI_SUCCESS;
 838     I2cHostI2cBusConfigurationAvailable (I2cHostContext->I2cBusConfigurationEvent, I2cHostContext);
 839
 840     //
 841     //  Release the thread synchronization
 842     //
 843     gBS->RestoreTPL (TplPrevious);
 844   }
 845
 846   return Status;
 847 }
 848
 849 /**
 850   Queue an I2C operation for execution on the I2C controller.
 851
 852   This routine must be called at or below TPL_NOTIFY.  For synchronous
 853   requests this routine must be called at or below TPL_CALLBACK.
 854
 855   N.B. The typical consumers of this API are the I2C bus driver and
 856   on rare occasions the I2C test application.  Extreme care must be
 857   taken by other consumers of this API to prevent confusing the
 858   third party I2C drivers due to a state change at the I2C device
 859   which the third party I2C drivers did not initiate.  I2C platform
 860   drivers may use this API within these guidelines.
 861
 862   This layer uses the concept of I2C bus configurations to describe
 863   the I2C bus.  An I2C bus configuration is defined as a unique
 864   setting of the multiplexers and switches in the I2C bus which
 865   enable access to one or more I2C devices.  When using a switch
 866   to divide a bus, due to speed differences, the I2C platform layer
 867   would define an I2C bus configuration for the I2C devices on each
 868   side of the switch.  When using a multiplexer, the I2C platform
 869   layer defines an I2C bus configuration for each of the selector
 870   values required to control the multiplexer.  See Figure 1 in the
 871   <a href="http://www.nxp.com/documents/user_manual/UM10204.pdf">I<sup>2</sup>C
 872   Specification</a> for a complex I2C bus configuration.
 873
 874   The I2C host driver processes all operations in FIFO order.  Prior to
 875   performing the operation, the I2C host driver calls the I2C platform
 876   driver to reconfigure the switches and multiplexers in the I2C bus
 877   enabling access to the specified I2C device.  The I2C platform driver
 878   also selects the maximum bus speed for the device.  After the I2C bus
 879   is configured, the I2C host driver calls the I2C port driver to
 880   initialize the I2C controller and start the I2C operation.
 881
 882   @param[in] This             Address of an EFI_I2C_HOST_PROTOCOL instance.
 883   @param[in] I2cBusConfiguration  I2C bus configuration to access the I2C
 884                                   device.
 885   @param[in] SlaveAddress     Address of the device on the I2C bus.
 886   @param[in] Event            Event to set for asynchronous operations,
 887                               NULL for synchronous operations
 888   @param[in] RequestPacket    Address of an EFI_I2C_REQUEST_PACKET
 889                               structure describing the I2C operation
 890   @param[out] I2cStatus       Optional buffer to receive the I2C operation
 891                               completion status
 892
 893   @retval EFI_SUCCESS           The operation completed successfully.
 894   @retval EFI_BAD_BUFFER_SIZE   The WriteBytes or ReadBytes buffer size is too large.
 895   @retval EFI_DEVICE_ERROR      There was an I2C error (NACK) during the operation.
 896                                 This could indicate the slave device is not present.
 897   @retval EFI_INVALID_PARAMETER RequestPacket is NULL
 898   @retval EFI_INVALID_PARAMETER TPL is too high
 899   @retval EFI_NO_MAPPING        Invalid I2cBusConfiguration value
 900   @retval EFI_NO_RESPONSE       The I2C device is not responding to the
 901                                 slave address.  EFI_DEVICE_ERROR may also be
 902                                 returned if the controller can not distinguish
 903                                 when the NACK occurred.
 904   @retval EFI_NOT_FOUND         I2C slave address exceeds maximum address
 905   @retval EFI_NOT_READY         I2C bus is busy or operation pending, wait for
 906                                 the event and then read status pointed to by
 907                                 the request packet.
 908   @retval EFI_OUT_OF_RESOURCES  Insufficient memory for I2C operation
 909   @retval EFI_TIMEOUT           The transaction did not complete within an internally
 910                                 specified timeout period.
 911
 912 **/
 913 EFI_STATUS
 914 EFIAPI
 915 I2cHostQueueRequest (
 916   IN CONST EFI_I2C_HOST_PROTOCOL  *This,
 917   IN UINTN                        I2cBusConfiguration,
 918   IN UINTN                        SlaveAddress,
 919   IN EFI_EVENT                    Event            OPTIONAL,
 920   IN EFI_I2C_REQUEST_PACKET       *RequestPacket,
 921   OUT EFI_STATUS                  *I2cStatus       OPTIONAL
 922   )
 923 {
 924   EFI_STATUS        Status;
 925   EFI_EVENT         SyncEvent;
 926   EFI_TPL           TplPrevious;
 927   I2C_REQUEST       *I2cRequest;
 928   I2C_HOST_CONTEXT  *I2cHostContext;
 929   BOOLEAN           FirstRequest;
 930   UINTN             RequestPacketSize;
 931   UINTN             StartBit;
 932
 933   SyncEvent    = NULL;
 934   FirstRequest = FALSE;
 935   Status       = EFI_SUCCESS;
 936
 937   if (RequestPacket == NULL) {
 938     return EFI_INVALID_PARAMETER;
 939   }
 940
 941   if ((SlaveAddress & I2C_ADDRESSING_10_BIT) != 0) {
 942     //
 943     // 10-bit address, bits 0-9 are used for 10-bit I2C slave addresses,
 944     // bits 10-30 are reserved bits and must be zero
 945     //
 946     StartBit = 10;
 947   } else {
 948     //
 949     // 7-bit address, Bits 0-6 are used for 7-bit I2C slave addresses,
 950     // bits 7-30 are reserved bits and must be zero
 951     //
 952     StartBit = 7;
 953   }
 954
 955   if (BitFieldRead32 ((UINT32)SlaveAddress, StartBit, 30) != 0) {
 956     //
 957     // Reserved bit set in the SlaveAddress parameter
 958     //
 959     return EFI_NOT_FOUND;
 960   }
 961
 962   I2cHostContext = I2C_HOST_CONTEXT_FROM_PROTOCOL (This);
 963
 964   if (Event == NULL) {
 965     //
 966     // For synchronous transaction, register an event used to wait for finishing synchronous transaction
 967     //
 968     Status = gBS->CreateEvent (
 969                     0,
 970                     TPL_I2C_SYNC,
 971                     NULL,
 972                     NULL,
 973                     &SyncEvent
 974                     );
 975     if (EFI_ERROR (Status)) {
 976       return Status;
 977     }
 978   }
 979
 980   //
 981   // TPL should be at or below TPL_NOTIFY.
 982   // For synchronous requests this routine must be called at or below TPL_CALLBACK.
 983   //
 984   TplPrevious = EfiGetCurrentTpl ();
 985   if ((TplPrevious > TPL_I2C_SYNC) || ((Event == NULL) && (TplPrevious > TPL_CALLBACK))) {
 986     DEBUG ((DEBUG_ERROR, "ERROR - TPL %d is too high!\n", TplPrevious));
 987     return EFI_INVALID_PARAMETER;
 988   }
 989
 990   //
 991   // Allocate the request structure
 992   //
 993   I2cRequest = AllocateZeroPool (sizeof (I2C_REQUEST));
 994   if (I2cRequest == NULL) {
 995     DEBUG ((DEBUG_ERROR, "WARNING - Failed to allocate I2C_REQUEST!\n"));
 996     return EFI_OUT_OF_RESOURCES;
 997   }
 998
 999   //
1000   // Initialize the request
1001   //
1002   I2cRequest->Signature           = I2C_REQUEST_SIGNATURE;
1003   I2cRequest->I2cBusConfiguration = I2cBusConfiguration;
1004   I2cRequest->SlaveAddress        = SlaveAddress;
1005   I2cRequest->Event               = (Event == NULL) ? SyncEvent : Event;
1006   I2cRequest->Status              = I2cStatus;
1007
1008   //
1009   // Copy request packet into private buffer, as RequestPacket may be freed during asynchronous transaction
1010   //
1011   RequestPacketSize         = sizeof (UINTN) + RequestPacket->OperationCount * sizeof (EFI_I2C_OPERATION);
1012   I2cRequest->RequestPacket = AllocateZeroPool (RequestPacketSize);
1013   ASSERT (I2cRequest->RequestPacket != NULL);
1014   CopyMem (I2cRequest->RequestPacket, RequestPacket, RequestPacketSize);
1015
1016   //
1017   // Synchronize with the other threads
1018   //
1019   gBS->RaiseTPL (TPL_I2C_SYNC);
1020
1021   FirstRequest = IsListEmpty (&I2cHostContext->RequestList);
1022
1023   //
1024   // Insert new I2C request in the list
1025   //
1026   InsertTailList (&I2cHostContext->RequestList, &I2cRequest->Link);
1027
1028   //
1029   // Release the thread synchronization
1030   //
1031   gBS->RestoreTPL (TplPrevious);
1032
1033   if (FirstRequest) {
1034     //
1035     // Start the first I2C request, then the subsequent of I2C request will continue
1036     //
1037     Status = I2cHostRequestEnable (I2cHostContext);
1038   }
1039
1040   if (Event != NULL) {
1041     //
1042     // For asynchronous, return EFI_SUCCESS indicating that the asynchronously I2C transaction was queued.
1043     // No real I2C operation status in I2cStatus
1044     //
1045     return EFI_SUCCESS;
1046   }
1047
1048   //
1049   // For synchronous transaction, wait for the operation completion
1050   //
1051   do {
1052     Status = gBS->CheckEvent (SyncEvent);
1053   } while (Status == EFI_NOT_READY);
1054
1055   //
1056   // Get the I2C operation status
1057   //
1058   Status = I2cHostContext->Status;
1059
1060   //
1061   // Return the I2C operation status
1062   //
1063   if (I2cStatus != NULL) {
1064     *I2cStatus = Status;
1065   }
1066
1067   //
1068   // Close the event if necessary
1069   //
1070   if (SyncEvent != NULL) {
1071     gBS->CloseEvent (SyncEvent);
1072   }
1073
1074   return Status;
1075 }
1076
1077 /**
1078   The user Entry Point for I2C host module. The user code starts with this function.
1079
1080   @param[in] ImageHandle    The firmware allocated handle for the EFI image.
1081   @param[in] SystemTable    A pointer to the EFI System Table.
1082
1083   @retval EFI_SUCCESS       The entry point is executed successfully.
1084   @retval other             Some error occurs when executing this entry point.
1085
1086 **/
1087 EFI_STATUS
1088 EFIAPI
1089 InitializeI2cHost (
1090   IN EFI_HANDLE        ImageHandle,
1091   IN EFI_SYSTEM_TABLE  *SystemTable
1092   )
1093 {
1094   EFI_STATUS  Status;
1095
1096   //
1097   // Install driver model protocol(s).
1098   //
1099   Status = EfiLibInstallDriverBindingComponentName2 (
1100              ImageHandle,
1101              SystemTable,
1102              &gI2cHostDriverBinding,
1103              ImageHandle,
1104              &gI2cHostComponentName,
1105              &gI2cHostComponentName2
1106              );
1107   ASSERT_EFI_ERROR (Status);
1108   return Status;
1109 }
1110
1111 /**
1112   This is the unload handle for I2C host module.
1113
1114   Disconnect the driver specified by ImageHandle from all the devices in the handle database.
1115   Uninstall all the protocols installed in the driver entry point.
1116
1117   @param[in] ImageHandle           The drivers' driver image.
1118
1119   @retval    EFI_SUCCESS           The image is unloaded.
1120   @retval    Others                Failed to unload the image.
1121
1122 **/
1123 EFI_STATUS
1124 EFIAPI
1125 I2cHostUnload (
1126   IN EFI_HANDLE  ImageHandle
1127   )
1128 {
1129   EFI_STATUS                    Status;
1130   EFI_HANDLE                    *DeviceHandleBuffer;
1131   UINTN                         DeviceHandleCount;
1132   UINTN                         Index;
1133   EFI_COMPONENT_NAME_PROTOCOL   *ComponentName;
1134   EFI_COMPONENT_NAME2_PROTOCOL  *ComponentName2;
1135
1136   //
1137   // Get the list of all I2C Controller handles in the handle database.
1138   // If there is an error getting the list, then the unload
1139   // operation fails.
1140   //
1141   Status = gBS->LocateHandleBuffer (
1142                   ByProtocol,
1143                   &gEfiI2cHostProtocolGuid,
1144                   NULL,
1145                   &DeviceHandleCount,
1146                   &DeviceHandleBuffer
1147                   );
1148
1149   if (!EFI_ERROR (Status)) {
1150     //
1151     // Disconnect the driver specified by ImageHandle from all
1152     // the devices in the handle database.
1153     //
1154     for (Index = 0; Index < DeviceHandleCount; Index++) {
1155       Status = gBS->DisconnectController (
1156                       DeviceHandleBuffer[Index],
1157                       ImageHandle,
1158                       NULL
1159                       );
1160       if (EFI_ERROR (Status)) {
1161         goto Done;
1162       }
1163     }
1164   }
1165
1166   //
1167   // Uninstall all the protocols installed in the driver entry point
1168   //
1169   Status = gBS->UninstallMultipleProtocolInterfaces (
1170                   gI2cHostDriverBinding.DriverBindingHandle,
1171                   &gEfiDriverBindingProtocolGuid,
1172                   &gI2cHostDriverBinding,
1173                   NULL
1174                   );
1175   ASSERT_EFI_ERROR (Status);
1176
1177   //
1178   // Note we have to one by one uninstall the following protocols.
1179   // It's because some of them are optionally installed based on
1180   // the following PCD settings.
1181   //   gEfiMdePkgTokenSpaceGuid.PcdDriverDiagnosticsDisable
1182   //   gEfiMdePkgTokenSpaceGuid.PcdComponentNameDisable
1183   //   gEfiMdePkgTokenSpaceGuid.PcdDriverDiagnostics2Disable
1184   //   gEfiMdePkgTokenSpaceGuid.PcdComponentName2Disable
1185   //
1186   Status = gBS->HandleProtocol (
1187                   gI2cHostDriverBinding.DriverBindingHandle,
1188                   &gEfiComponentNameProtocolGuid,
1189                   (VOID **)&ComponentName
1190                   );
1191   if (!EFI_ERROR (Status)) {
1192     gBS->UninstallProtocolInterface (
1193            gI2cHostDriverBinding.DriverBindingHandle,
1194            &gEfiComponentNameProtocolGuid,
1195            ComponentName
1196            );
1197   }
1198
1199   Status = gBS->HandleProtocol (
1200                   gI2cHostDriverBinding.DriverBindingHandle,
1201                   &gEfiComponentName2ProtocolGuid,
1202                   (VOID **)&ComponentName2
1203                   );
1204   if (!EFI_ERROR (Status)) {
1205     gBS->UninstallProtocolInterface (
1206            gI2cHostDriverBinding.DriverBindingHandle,
1207            &gEfiComponentName2ProtocolGuid,
1208            ComponentName2
1209            );
1210   }
1211
1212   Status = EFI_SUCCESS;
1213
1214 Done:
1215   //
1216   // Free the buffer containing the list of handles from the handle database
1217   //
1218   if (DeviceHandleBuffer != NULL) {
1219     gBS->FreePool (DeviceHandleBuffer);
1220   }
1221
1222   return Status;
1223 }