diff options
Diffstat (limited to 'MdeModulePkg/Bus/I2c/I2cDxe/I2cBus.c')
| -rw-r--r-- | MdeModulePkg/Bus/I2c/I2cDxe/I2cBus.c | 1468 |
1 files changed, 1468 insertions, 0 deletions
diff --git a/MdeModulePkg/Bus/I2c/I2cDxe/I2cBus.c b/MdeModulePkg/Bus/I2c/I2cDxe/I2cBus.c new file mode 100644 index 0000000000..3da1474edc --- /dev/null +++ b/MdeModulePkg/Bus/I2c/I2cDxe/I2cBus.c @@ -0,0 +1,1468 @@ +/** @file
+ This file implements I2C IO Protocol which enables the user to manipulate a single
+ I2C device independent of the host controller and I2C design.
+
+ Copyright (c) 2013, Intel Corporation. All rights reserved.<BR>
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include "I2cDxe.h"
+
+//
+// EFI_DRIVER_BINDING_PROTOCOL instance
+//
+EFI_DRIVER_BINDING_PROTOCOL gI2cBusDriverBinding = {
+ I2cBusDriverSupported,
+ I2cBusDriverStart,
+ I2cBusDriverStop,
+ 0x10,
+ NULL,
+ NULL
+};
+
+//
+// Template for I2C Bus Child Device.
+//
+I2C_DEVICE_CONTEXT gI2cDeviceContextTemplate = {
+ I2C_DEVICE_SIGNATURE,
+ NULL,
+ { // I2cIo Protocol
+ I2cBusQueueRequest, // QueueRequest
+ NULL, // DeviceGuid
+ 0, // DeviceIndex
+ 0, // HardwareRevision
+ NULL // I2cControllerCapabilities
+ },
+ NULL, // DevicePath
+ NULL, // I2cDevice
+ NULL, // I2cBusContext
+};
+
+//
+// Template for controller device path node.
+//
+CONTROLLER_DEVICE_PATH gControllerDevicePathTemplate = {
+ {
+ HARDWARE_DEVICE_PATH,
+ HW_CONTROLLER_DP,
+ {
+ (UINT8) (sizeof (CONTROLLER_DEVICE_PATH)),
+ (UINT8) ((sizeof (CONTROLLER_DEVICE_PATH)) >> 8)
+ }
+ },
+ 0
+};
+
+//
+// Template for vendor device path node.
+//
+VENDOR_DEVICE_PATH gVendorDevicePathTemplate = {
+ {
+ HARDWARE_DEVICE_PATH,
+ HW_VENDOR_DP,
+ {
+ (UINT8) (sizeof (VENDOR_DEVICE_PATH)),
+ (UINT8) ((sizeof (VENDOR_DEVICE_PATH)) >> 8)
+ }
+ },
+ { 0x0, 0x0, 0x0, { 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 }}
+};
+
+//
+// Driver name table
+//
+GLOBAL_REMOVE_IF_UNREFERENCED EFI_UNICODE_STRING_TABLE mI2cBusDriverNameTable[] = {
+ { "eng;en", (CHAR16 *) L"I2C Bus Driver" },
+ { NULL , NULL }
+};
+
+//
+// EFI Component Name Protocol
+//
+GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME_PROTOCOL gI2cBusComponentName = {
+ (EFI_COMPONENT_NAME_GET_DRIVER_NAME) I2cBusComponentNameGetDriverName,
+ (EFI_COMPONENT_NAME_GET_CONTROLLER_NAME) I2cBusComponentNameGetControllerName,
+ "eng"
+};
+
+//
+// EFI Component Name 2 Protocol
+//
+GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME2_PROTOCOL gI2cBusComponentName2 = {
+ I2cBusComponentNameGetDriverName,
+ I2cBusComponentNameGetControllerName,
+ "en"
+};
+
+/**
+ Retrieves a Unicode string that is the user readable name of the driver.
+
+ This function retrieves the user readable name of a driver in the form of a
+ Unicode string. If the driver specified by This has a user readable name in
+ the language specified by Language, then a pointer to the driver name is
+ returned in DriverName, and EFI_SUCCESS is returned. If the driver specified
+ by This does not support the language specified by Language,
+ then EFI_UNSUPPORTED is returned.
+
+ @param This[in] A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
+ EFI_COMPONENT_NAME_PROTOCOL instance.
+
+ @param Language[in] A pointer to a Null-terminated ASCII string
+ array indicating the language. This is the
+ language of the driver name that the caller is
+ requesting, and it must match one of the
+ languages specified in SupportedLanguages. The
+ number of languages supported by a driver is up
+ to the driver writer. Language is specified
+ in RFC 4646 or ISO 639-2 language code format.
+
+ @param DriverName[out] A pointer to the Unicode string to return.
+ This Unicode string is the name of the
+ driver specified by This in the language
+ specified by Language.
+
+ @retval EFI_SUCCESS The Unicode string for the Driver specified by
+ This and the language specified by Language was
+ returned in DriverName.
+
+ @retval EFI_INVALID_PARAMETER Language is NULL.
+
+ @retval EFI_INVALID_PARAMETER DriverName is NULL.
+
+ @retval EFI_UNSUPPORTED The driver specified by This does not support
+ the language specified by Language.
+
+**/
+EFI_STATUS
+EFIAPI
+I2cBusComponentNameGetDriverName (
+ IN EFI_COMPONENT_NAME2_PROTOCOL *This,
+ IN CHAR8 *Language,
+ OUT CHAR16 **DriverName
+ )
+{
+ return LookupUnicodeString2 (
+ Language,
+ This->SupportedLanguages,
+ mI2cBusDriverNameTable,
+ DriverName,
+ (BOOLEAN)(This != &gI2cBusComponentName2)
+ );
+}
+
+/**
+ Retrieves a Unicode string that is the user readable name of the controller
+ that is being managed by a driver.
+
+ This function retrieves the user readable name of the controller specified by
+ ControllerHandle and ChildHandle in the form of a Unicode string. If the
+ driver specified by This has a user readable name in the language specified by
+ Language, then a pointer to the controller name is returned in ControllerName,
+ and EFI_SUCCESS is returned. If the driver specified by This is not currently
+ managing the controller specified by ControllerHandle and ChildHandle,
+ then EFI_UNSUPPORTED is returned. If the driver specified by This does not
+ support the language specified by Language, then EFI_UNSUPPORTED is returned.
+
+ @param This[in] A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
+ EFI_COMPONENT_NAME_PROTOCOL instance.
+
+ @param ControllerHandle[in] The handle of a controller that the driver
+ specified by This is managing. This handle
+ specifies the controller whose name is to be
+ returned.
+
+ @param ChildHandle[in] The handle of the child controller to retrieve
+ the name of. This is an optional parameter that
+ may be NULL. It will be NULL for device
+ drivers. It will also be NULL for a bus drivers
+ that wish to retrieve the name of the bus
+ controller. It will not be NULL for a bus
+ driver that wishes to retrieve the name of a
+ child controller.
+
+ @param Language[in] A pointer to a Null-terminated ASCII string
+ array indicating the language. This is the
+ language of the driver name that the caller is
+ requesting, and it must match one of the
+ languages specified in SupportedLanguages. The
+ number of languages supported by a driver is up
+ to the driver writer. Language is specified in
+ RFC 4646 or ISO 639-2 language code format.
+
+ @param ControllerName[out] A pointer to the Unicode string to return.
+ This Unicode string is the name of the
+ controller specified by ControllerHandle and
+ ChildHandle in the language specified by
+ Language from the point of view of the driver
+ specified by This.
+
+ @retval EFI_SUCCESS The Unicode string for the user readable name in
+ the language specified by Language for the
+ driver specified by This was returned in
+ DriverName.
+
+ @retval EFI_INVALID_PARAMETER ControllerHandle is NULL.
+
+ @retval EFI_INVALID_PARAMETER ChildHandle is not NULL and it is not a valid
+ EFI_HANDLE.
+
+ @retval EFI_INVALID_PARAMETER Language is NULL.
+
+ @retval EFI_INVALID_PARAMETER ControllerName is NULL.
+
+ @retval EFI_UNSUPPORTED The driver specified by This is not currently
+ managing the controller specified by
+ ControllerHandle and ChildHandle.
+
+ @retval EFI_UNSUPPORTED The driver specified by This does not support
+ the language specified by Language.
+
+**/
+EFI_STATUS
+EFIAPI
+I2cBusComponentNameGetControllerName (
+ IN EFI_COMPONENT_NAME2_PROTOCOL *This,
+ IN EFI_HANDLE ControllerHandle,
+ IN EFI_HANDLE ChildHandle OPTIONAL,
+ IN CHAR8 *Language,
+ OUT CHAR16 **ControllerName
+ )
+{
+ return EFI_UNSUPPORTED;
+}
+
+/**
+ Check if the child of I2C controller has been created.
+
+ @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
+ @param[in] Controller I2C controller handle.
+ @param[in] RemainingDevicePath A pointer to the remaining portion of a device path.
+ @param[in] RemainingHasControllerNode Indicate if RemainingDevicePath contains CONTROLLER_DEVICE_PATH.
+ @param[in] RemainingControllerNumber Controller number in CONTROLLER_DEVICE_PATH.
+
+ @retval EFI_SUCCESS The child of I2C controller is not created.
+ @retval Others The child of I2C controller has been created or other errors happen.
+
+**/
+EFI_STATUS
+CheckRemainingDevicePath (
+ IN EFI_DRIVER_BINDING_PROTOCOL *This,
+ IN EFI_HANDLE Controller,
+ IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath,
+ IN BOOLEAN RemainingHasControllerNode,
+ IN UINT32 RemainingControllerNumber
+ )
+{
+ EFI_STATUS Status;
+ EFI_DEVICE_PATH_PROTOCOL *SystemDevicePath;
+ EFI_OPEN_PROTOCOL_INFORMATION_ENTRY *OpenInfoBuffer;
+ UINTN EntryCount;
+ UINTN Index;
+ BOOLEAN SystemHasControllerNode;
+ UINT32 SystemControllerNumber;
+
+ SystemHasControllerNode = FALSE;
+ SystemControllerNumber = 0;
+
+ Status = gBS->OpenProtocolInformation (
+ Controller,
+ &gEfiI2cHostProtocolGuid,
+ &OpenInfoBuffer,
+ &EntryCount
+ );
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ for (Index = 0; Index < EntryCount; Index++) {
+ if ((OpenInfoBuffer[Index].Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) != 0) {
+ Status = gBS->OpenProtocol (
+ OpenInfoBuffer[Index].ControllerHandle,
+ &gEfiDevicePathProtocolGuid,
+ (VOID **) &SystemDevicePath,
+ This->DriverBindingHandle,
+ Controller,
+ EFI_OPEN_PROTOCOL_GET_PROTOCOL
+ );
+ if (!EFI_ERROR (Status)) {
+ //
+ // Find vendor device path node and compare
+ //
+ while (!IsDevicePathEnd (SystemDevicePath)) {
+ if ((DevicePathType (SystemDevicePath) == HARDWARE_DEVICE_PATH) &&
+ (DevicePathSubType (SystemDevicePath) == HW_VENDOR_DP)) {
+ //
+ // Check if vendor device path is same between system device path and remaining device path
+ //
+ if (CompareMem (SystemDevicePath, RemainingDevicePath, sizeof (VENDOR_DEVICE_PATH)) == 0) {
+ //
+ // Get controller node appended after vendor node
+ //
+ SystemDevicePath = NextDevicePathNode (SystemDevicePath);
+ if ((DevicePathType (SystemDevicePath) == HARDWARE_DEVICE_PATH) &&
+ (DevicePathSubType (SystemDevicePath) == HW_CONTROLLER_DP)) {
+ SystemHasControllerNode = TRUE;
+ SystemControllerNumber = ((CONTROLLER_DEVICE_PATH *) SystemDevicePath)->ControllerNumber;
+ } else {
+ SystemHasControllerNode = FALSE;
+ SystemControllerNumber = 0;
+ }
+ if (((SystemHasControllerNode) && (!RemainingHasControllerNode) && (SystemControllerNumber == 0)) ||
+ ((!SystemHasControllerNode) && (RemainingHasControllerNode) && (RemainingControllerNumber == 0)) ||
+ ((SystemHasControllerNode) && (RemainingHasControllerNode) && (SystemControllerNumber == RemainingControllerNumber)) ||
+ ((!SystemHasControllerNode) && (!RemainingHasControllerNode))) {
+ DEBUG ((EFI_D_ERROR, "This I2C device has been already started.\n"));
+ Status = EFI_UNSUPPORTED;
+ break;
+ }
+ }
+ }
+ SystemDevicePath = NextDevicePathNode (SystemDevicePath);
+ }
+ if (EFI_ERROR (Status)) {
+ break;
+ }
+ }
+ }
+ }
+ FreePool (OpenInfoBuffer);
+ return Status;
+}
+
+/**
+ Tests to see if this driver supports a given controller. If a child device is provided,
+ it further tests to see if this driver supports creating a handle for the specified child device.
+
+ This function checks to see if the driver specified by This supports the device specified by
+ ControllerHandle. Drivers will typically use the device path attached to
+ ControllerHandle and/or the services from the bus I/O abstraction attached to
+ ControllerHandle to determine if the driver supports ControllerHandle. This function
+ may be called many times during platform initialization. In order to reduce boot times, the tests
+ performed by this function must be very small, and take as little time as possible to execute. This
+ function must not change the state of any hardware devices, and this function must be aware that the
+ device specified by ControllerHandle may already be managed by the same driver or a
+ different driver. This function must match its calls to AllocatePages() with FreePages(),
+ AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().
+ Since ControllerHandle may have been previously started by the same driver, if a protocol is
+ already in the opened state, then it must not be closed with CloseProtocol(). This is required
+ to guarantee the state of ControllerHandle is not modified by this function.
+
+ @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
+ @param[in] ControllerHandle The handle of the controller to test. This handle
+ must support a protocol interface that supplies
+ an I/O abstraction to the driver.
+ @param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This
+ parameter is ignored by device drivers, and is optional for bus
+ drivers. For bus drivers, if this parameter is not NULL, then
+ the bus driver must determine if the bus controller specified
+ by ControllerHandle and the child controller specified
+ by RemainingDevicePath are both supported by this
+ bus driver.
+
+ @retval EFI_SUCCESS The device specified by ControllerHandle and
+ RemainingDevicePath is supported by the driver specified by This.
+ @retval EFI_ALREADY_STARTED The device specified by ControllerHandle and
+ RemainingDevicePath is already being managed by the driver
+ specified by This.
+ @retval EFI_ACCESS_DENIED The device specified by ControllerHandle and
+ RemainingDevicePath is already being managed by a different
+ driver or an application that requires exclusive access.
+ Currently not implemented.
+ @retval EFI_UNSUPPORTED The device specified by ControllerHandle and
+ RemainingDevicePath is not supported by the driver specified by This.
+**/
+EFI_STATUS
+EFIAPI
+I2cBusDriverSupported (
+ IN EFI_DRIVER_BINDING_PROTOCOL *This,
+ IN EFI_HANDLE Controller,
+ IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
+ )
+{
+ EFI_STATUS Status;
+ EFI_I2C_ENUMERATE_PROTOCOL *I2cEnumerate;
+ EFI_I2C_HOST_PROTOCOL *I2cHost;
+ EFI_DEVICE_PATH_PROTOCOL *ParentDevicePath;
+ EFI_DEVICE_PATH_PROTOCOL *DevPathNode;
+ BOOLEAN RemainingHasControllerNode;
+ UINT32 RemainingControllerNumber;
+
+ RemainingHasControllerNode = FALSE;
+ RemainingControllerNumber = 0;
+
+ //
+ // Determine if the I2c Enumerate Protocol is available
+ //
+ Status = gBS->OpenProtocol (
+ Controller,
+ &gEfiI2cEnumerateProtocolGuid,
+ (VOID **) &I2cEnumerate,
+ This->DriverBindingHandle,
+ Controller,
+ EFI_OPEN_PROTOCOL_BY_DRIVER
+ );
+ if ((EFI_ERROR (Status)) && (Status != EFI_ALREADY_STARTED)) {
+ return Status;
+ }
+
+ if (!EFI_ERROR (Status)) {
+ gBS->CloseProtocol (
+ Controller,
+ &gEfiI2cEnumerateProtocolGuid,
+ This->DriverBindingHandle,
+ Controller
+ );
+ }
+
+ Status = gBS->OpenProtocol (
+ Controller,
+ &gEfiDevicePathProtocolGuid,
+ (VOID **) &ParentDevicePath,
+ This->DriverBindingHandle,
+ Controller,
+ EFI_OPEN_PROTOCOL_BY_DRIVER
+ );
+
+ if ((EFI_ERROR (Status)) && (Status != EFI_ALREADY_STARTED)) {
+ return Status;
+ }
+
+ if (!EFI_ERROR (Status)) {
+ gBS->CloseProtocol (
+ Controller,
+ &gEfiDevicePathProtocolGuid,
+ This->DriverBindingHandle,
+ Controller
+ );
+ }
+
+ if ((RemainingDevicePath != NULL) && !IsDevicePathEnd (RemainingDevicePath)) {
+ //
+ // Check if the first node of RemainingDevicePath is a hardware vendor device path
+ //
+ if ((DevicePathType (RemainingDevicePath) != HARDWARE_DEVICE_PATH) ||
+ (DevicePathSubType (RemainingDevicePath) != HW_VENDOR_DP)) {
+ return EFI_UNSUPPORTED;
+ }
+ //
+ // Check if the second node of RemainingDevicePath is a controller node
+ //
+ DevPathNode = NextDevicePathNode (RemainingDevicePath);
+ if (!IsDevicePathEnd (DevPathNode)) {
+ if ((DevicePathType (DevPathNode) != HARDWARE_DEVICE_PATH) ||
+ (DevicePathSubType (DevPathNode) != HW_CONTROLLER_DP)) {
+ return EFI_UNSUPPORTED;
+ } else {
+ RemainingHasControllerNode = TRUE;
+ RemainingControllerNumber = ((CONTROLLER_DEVICE_PATH *) DevPathNode)->ControllerNumber;
+ }
+ }
+ }
+
+ //
+ // Determine if the I2C Host Protocol is available
+ //
+ Status = gBS->OpenProtocol (
+ Controller,
+ &gEfiI2cHostProtocolGuid,
+ (VOID **) &I2cHost,
+ This->DriverBindingHandle,
+ Controller,
+ EFI_OPEN_PROTOCOL_BY_DRIVER
+ );
+
+ if (!EFI_ERROR (Status)) {
+ gBS->CloseProtocol (
+ Controller,
+ &gEfiI2cHostProtocolGuid,
+ This->DriverBindingHandle,
+ Controller
+ );
+ }
+
+
+ if (Status == EFI_ALREADY_STARTED) {
+ if ((RemainingDevicePath == NULL) ||
+ ((RemainingDevicePath != NULL) && IsDevicePathEnd (RemainingDevicePath))) {
+ //
+ // If RemainingDevicePath is NULL or is the End of Device Path Node, return EFI_SUCCESS.
+ //
+ Status = EFI_SUCCESS;
+ } else {
+ //
+ // Test if the child with the RemainingDevicePath has already been created.
+ //
+ Status = CheckRemainingDevicePath (
+ This,
+ Controller,
+ RemainingDevicePath,
+ RemainingHasControllerNode,
+ RemainingControllerNumber
+ );
+ }
+ }
+
+ return Status;
+}
+
+/**
+ Starts a device controller or a bus controller.
+
+ The Start() function is designed to be invoked from the EFI boot service ConnectController().
+ As a result, much of the error checking on the parameters to Start() has been moved into this
+ common boot service. It is legal to call Start() from other locations,
+ but the following calling restrictions must be followed or the system behavior will not be deterministic.
+ 1. ControllerHandle must be a valid EFI_HANDLE.
+ 2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
+ EFI_DEVICE_PATH_PROTOCOL.
+ 3. Prior to calling Start(), the Supported() function for the driver specified by This must
+ have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.
+
+ @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
+ @param[in] ControllerHandle The handle of the controller to start. This handle
+ must support a protocol interface that supplies
+ an I/O abstraction to the driver.
+ @param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This
+ parameter is ignored by device drivers, and is optional for bus
+ drivers. For a bus driver, if this parameter is NULL, then handles
+ for all the children of Controller are created by this driver.
+ If this parameter is not NULL and the first Device Path Node is
+ not the End of Device Path Node, then only the handle for the
+ child device specified by the first Device Path Node of
+ RemainingDevicePath is created by this driver.
+ If the first Device Path Node of RemainingDevicePath is
+ the End of Device Path Node, no child handle is created by this
+ driver.
+
+ @retval EFI_SUCCESS The device was started.
+ @retval EFI_DEVICE_ERROR The device could not be started due to a device error.Currently not implemented.
+ @retval EFI_OUT_OF_RESOURCES The request could not be completed due to a lack of resources.
+ @retval Others The driver failded to start the device.
+
+**/
+EFI_STATUS
+EFIAPI
+I2cBusDriverStart (
+ IN EFI_DRIVER_BINDING_PROTOCOL *This,
+ IN EFI_HANDLE Controller,
+ IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
+ )
+{
+ EFI_I2C_ENUMERATE_PROTOCOL *I2cEnumerate;
+ EFI_I2C_HOST_PROTOCOL *I2cHost;
+ I2C_BUS_CONTEXT *I2cBusContext;
+ EFI_STATUS Status;
+ EFI_DEVICE_PATH_PROTOCOL *ParentDevicePath;
+
+ I2cBusContext = NULL;
+ ParentDevicePath = NULL;
+ I2cEnumerate = NULL;
+ I2cHost = NULL;
+
+ //
+ // Determine if the I2C controller is available
+ //
+ Status = gBS->OpenProtocol (
+ Controller,
+ &gEfiI2cHostProtocolGuid,
+ (VOID**)&I2cHost,
+ This->DriverBindingHandle,
+ Controller,
+ EFI_OPEN_PROTOCOL_BY_DRIVER
+ );
+ if (EFI_ERROR (Status) && (Status != EFI_ALREADY_STARTED)) {
+ DEBUG ((EFI_D_ERROR, "I2cBus: open I2C host error, Status = %r\n", Status));
+ return Status;
+ }
+
+ if (Status == EFI_ALREADY_STARTED) {
+ Status = gBS->OpenProtocol (
+ Controller,
+ &gEfiCallerIdGuid,
+ (VOID **) &I2cBusContext,
+ This->DriverBindingHandle,
+ Controller,
+ EFI_OPEN_PROTOCOL_GET_PROTOCOL
+ );
+ if (EFI_ERROR (Status)) {
+ DEBUG ((EFI_D_ERROR, "I2cBus: open private protocol error, Status = %r.\n", Status));
+ return Status;
+ }
+ }
+
+ //
+ // Get the I2C bus enumeration API
+ //
+ Status = gBS->OpenProtocol (
+ Controller,
+ &gEfiI2cEnumerateProtocolGuid,
+ (VOID**)&I2cEnumerate,
+ This->DriverBindingHandle,
+ Controller,
+ EFI_OPEN_PROTOCOL_BY_DRIVER
+ );
+ if (EFI_ERROR (Status) && (Status != EFI_ALREADY_STARTED)) {
+ DEBUG ((EFI_D_ERROR, "I2cBus: open I2C enumerate error, Status = %r\n", Status));
+ goto Error;
+ }
+
+ Status = gBS->OpenProtocol (
+ Controller,
+ &gEfiDevicePathProtocolGuid,
+ (VOID **) &ParentDevicePath,
+ This->DriverBindingHandle,
+ Controller,
+ EFI_OPEN_PROTOCOL_BY_DRIVER
+ );
+ if (EFI_ERROR (Status) && (Status != EFI_ALREADY_STARTED)) {
+ DEBUG ((EFI_D_ERROR, "I2cBus: open device path error, Status = %r\n", Status));
+ goto Error;
+ }
+
+ if ((RemainingDevicePath != NULL) && IsDevicePathEnd (RemainingDevicePath)) {
+ //
+ // If RemainingDevicePath is the End of Device Path Node,
+ // don't create any child device and return EFI_SUCESS
+ //
+ return EFI_SUCCESS;
+ }
+
+ //
+ // Allocate the buffer for I2C_BUS_CONTEXT if it is not allocated before.
+ //
+ if (I2cBusContext == NULL) {
+ //
+ // Allocate the I2C context structure for the current I2C controller
+ //
+ I2cBusContext = AllocateZeroPool (sizeof (I2C_BUS_CONTEXT));
+ if (I2cBusContext == NULL) {
+ DEBUG ((EFI_D_ERROR, "I2cBus: there is no enough memory to allocate.\n"));
+ Status = EFI_OUT_OF_RESOURCES;
+ goto Error;
+ }
+
+ /*
+ +----------------+
+ .->| I2C_BUS_CONTEXT|<----- This file Protocol (gEfiCallerIdGuid) installed on I2C Controller handle
+ | +----------------+
+ |
+ | +----------------------------+
+ | | I2C_DEVICE_CONTEXT |
+ `--| |
+ | |
+ | I2C IO Protocol Structure | <----- I2C IO Protocol
+ | |
+ +----------------------------+
+
+ */
+ I2cBusContext->I2cHost = I2cHost;
+ I2cBusContext->I2cEnumerate = I2cEnumerate;
+ //
+ // Parent controller used to create children
+ //
+ I2cBusContext->Controller = Controller;
+ //
+ // Parent controller device path used to create children device path
+ //
+ I2cBusContext->ParentDevicePath = ParentDevicePath;
+
+ I2cBusContext->DriverBindingHandle = This->DriverBindingHandle;
+
+ Status = gBS->InstallMultipleProtocolInterfaces (
+ &Controller,
+ &gEfiCallerIdGuid,
+ I2cBusContext,
+ NULL
+ );
+ if (EFI_ERROR (Status)) {
+ DEBUG ((EFI_D_ERROR, "I2cBus: install private protocol error, Status = %r.\n", Status));
+ goto Error;
+ }
+ }
+
+ //
+ // Start the driver
+ //
+ Status = RegisterI2cDevice (I2cBusContext, Controller, RemainingDevicePath);
+
+ return Status;
+
+Error:
+ if (EFI_ERROR (Status)) {
+ DEBUG ((EFI_D_ERROR, "I2cBus: Start() function failed, Status = %r\n", Status));
+ if (ParentDevicePath != NULL) {
+ gBS->CloseProtocol (
+ Controller,
+ &gEfiDevicePathProtocolGuid,
+ This->DriverBindingHandle,
+ Controller
+ );
+ }
+
+ if (I2cHost != NULL) {
+ gBS->CloseProtocol (
+ Controller,
+ &gEfiI2cHostProtocolGuid,
+ This->DriverBindingHandle,
+ Controller
+ );
+ }
+
+ if (I2cEnumerate != NULL) {
+ gBS->CloseProtocol (
+ Controller,
+ &gEfiI2cEnumerateProtocolGuid,
+ This->DriverBindingHandle,
+ Controller
+ );
+ }
+
+ if (I2cBusContext != NULL) {
+ Status = gBS->UninstallMultipleProtocolInterfaces (
+ &Controller,
+ gEfiCallerIdGuid,
+ I2cBusContext,
+ NULL
+ );
+ FreePool (I2cBusContext);
+ }
+ }
+
+ //
+ // Return the operation status.
+ //
+ return Status;
+}
+
+
+/**
+ Stops a device controller or a bus controller.
+
+ The Stop() function is designed to be invoked from the EFI boot service DisconnectController().
+ As a result, much of the error checking on the parameters to Stop() has been moved
+ into this common boot service. It is legal to call Stop() from other locations,
+ but the following calling restrictions must be followed or the system behavior will not be deterministic.
+ 1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
+ same driver's Start() function.
+ 2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
+ EFI_HANDLE. In addition, all of these handles must have been created in this driver's
+ Start() function, and the Start() function must have called OpenProtocol() on
+ ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
+
+ @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
+ @param[in] ControllerHandle A handle to the device being stopped. The handle must
+ support a bus specific I/O protocol for the driver
+ to use to stop the device.
+ @param[in] NumberOfChildren The number of child device handles in ChildHandleBuffer.
+ @param[in] ChildHandleBuffer An array of child handles to be freed. May be NULL
+ if NumberOfChildren is 0.
+
+ @retval EFI_SUCCESS The device was stopped.
+ @retval EFI_DEVICE_ERROR The device could not be stopped due to a device error.
+
+**/
+EFI_STATUS
+EFIAPI
+I2cBusDriverStop (
+ IN EFI_DRIVER_BINDING_PROTOCOL *This,
+ IN EFI_HANDLE Controller,
+ IN UINTN NumberOfChildren,
+ IN EFI_HANDLE *ChildHandleBuffer
+ )
+{
+ I2C_BUS_CONTEXT *I2cBusContext;
+ EFI_STATUS Status;
+ BOOLEAN AllChildrenStopped;
+ UINTN Index;
+
+ if (NumberOfChildren == 0) {
+ gBS->CloseProtocol (
+ Controller,
+ &gEfiDevicePathProtocolGuid,
+ This->DriverBindingHandle,
+ Controller
+ );
+
+ gBS->CloseProtocol (
+ Controller,
+ &gEfiI2cHostProtocolGuid,
+ This->DriverBindingHandle,
+ Controller
+ );
+
+ gBS->CloseProtocol (
+ Controller,
+ &gEfiI2cEnumerateProtocolGuid,
+ This->DriverBindingHandle,
+ Controller
+ );
+
+ Status = gBS->OpenProtocol (
+ Controller,
+ &gEfiCallerIdGuid,
+ (VOID **) &I2cBusContext,
+ This->DriverBindingHandle,
+ Controller,
+ EFI_OPEN_PROTOCOL_GET_PROTOCOL
+ );
+ if (!EFI_ERROR (Status)) {
+ gBS->UninstallMultipleProtocolInterfaces (
+ Controller,
+ &gEfiCallerIdGuid,
+ I2cBusContext,
+ NULL
+ );
+ //
+ // No more child now, free bus context data.
+ //
+ FreePool (I2cBusContext);
+ }
+ return Status;
+ }
+
+ AllChildrenStopped = TRUE;
+
+ for (Index = 0; Index < NumberOfChildren; Index++) {
+
+ Status = UnRegisterI2cDevice (This, Controller, ChildHandleBuffer[Index]);
+ if (EFI_ERROR (Status)) {
+ AllChildrenStopped = FALSE;
+ }
+ }
+
+ if (!AllChildrenStopped) {
+ return EFI_DEVICE_ERROR;
+ }
+ return EFI_SUCCESS;
+}
+
+/**
+ Enumerate the I2C bus
+
+ This routine walks the platform specific data describing the
+ I2C bus to create the I2C devices where driver GUIDs were
+ specified.
+
+ @param[in] I2cBusContext Address of an I2C_BUS_CONTEXT structure
+ @param[in] Controller Handle to the controller
+ @param[in] RemainingDevicePath A pointer to the remaining portion of a device path.
+
+ @retval EFI_SUCCESS The bus is successfully configured
+
+**/
+EFI_STATUS
+RegisterI2cDevice (
+ IN I2C_BUS_CONTEXT *I2cBusContext,
+ IN EFI_HANDLE Controller,
+ IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
+ )
+{
+ I2C_DEVICE_CONTEXT *I2cDeviceContext;
+ EFI_STATUS Status;
+ CONST EFI_I2C_DEVICE *Device;
+ CONST EFI_I2C_DEVICE *TempDevice;
+ UINT32 RemainingPathDeviceIndex;
+ EFI_DEVICE_PATH_PROTOCOL *DevPathNode;
+ BOOLEAN BuildControllerNode;
+ UINTN Count;
+
+ Status = EFI_SUCCESS;
+ BuildControllerNode = TRUE;
+
+ //
+ // Default DeviceIndex
+ //
+ RemainingPathDeviceIndex = 0;
+
+ //
+ // Determine the controller number in Controller Node Device Path when RemainingDevicePath is not NULL.
+ //
+ if (RemainingDevicePath != NULL) {
+ //
+ // Check if there is a controller node appended after vendor node
+ //
+ DevPathNode = NextDevicePathNode (RemainingDevicePath);
+ if ((DevicePathType (DevPathNode) == HARDWARE_DEVICE_PATH) &&
+ (DevicePathSubType(DevPathNode) == HW_CONTROLLER_DP)) {
+ //
+ // RemainingDevicePath != NULL and RemainingDevicePath contains Controller Node,
+ // add Controller Node to Device Path on child handle.
+ //
+ RemainingPathDeviceIndex = ((CONTROLLER_DEVICE_PATH *) DevPathNode)->ControllerNumber;
+ } else {
+ //
+ // RemainingDevicePath != NULL and RemainingDevicePath does not contain Controller Node,
+ // do not add controller node to Device Path on child handle.
+ //
+ BuildControllerNode = FALSE;
+ }
+ }
+
+ //
+ // Walk the list of I2C devices on this bus
+ //
+ Device = NULL;
+ while (TRUE) {
+ //
+ // Get the next I2C device
+ //
+ Status = I2cBusContext->I2cEnumerate->Enumerate (I2cBusContext->I2cEnumerate, &Device);
+ if (EFI_ERROR (Status) || Device == NULL) {
+ if (RemainingDevicePath != NULL) {
+ Status = EFI_NOT_FOUND;
+ } else {
+ Status = EFI_SUCCESS;
+ }
+ break;
+ }
+
+ //
+ // Determine if the device info is valid
+ //
+ if ((Device->DeviceGuid == NULL) || (Device->SlaveAddressCount == 0) || (Device->SlaveAddressArray == NULL)) {
+ DEBUG ((EFI_D_ERROR, "Invalid EFI_I2C_DEVICE reported by I2c Enumerate protocol.\n"));
+ continue;
+ }
+
+ if (RemainingDevicePath == NULL) {
+ if (Device->DeviceIndex == 0) {
+ //
+ // Determine if the controller node is necessary when controller number is zero in I2C device
+ //
+ TempDevice = NULL;
+ Count = 0;
+ while (TRUE) {
+ //
+ // Get the next I2C device
+ //
+ Status = I2cBusContext->I2cEnumerate->Enumerate (I2cBusContext->I2cEnumerate, &TempDevice);
+ if (EFI_ERROR (Status) || TempDevice == NULL) {
+ Status = EFI_SUCCESS;
+ break;
+ }
+ if (CompareGuid (Device->DeviceGuid, TempDevice->DeviceGuid)) {
+ Count++;
+ }
+ }
+ if (Count == 1) {
+ //
+ // RemainingDevicePath == NULL and only DeviceIndex 0 is present on the I2C bus,
+ // do not add Controller Node to Device Path on child handle.
+ //
+ BuildControllerNode = FALSE;
+ }
+ }
+ } else {
+ //
+ // Find I2C device reported in Remaining Device Path
+ //
+ if ((!CompareGuid (&((VENDOR_DEVICE_PATH *)RemainingDevicePath)->Guid, Device->DeviceGuid)) ||
+ (RemainingPathDeviceIndex != Device->DeviceIndex)) {
+ continue;
+ }
+ }
+
+ //
+ // Build the device context for current I2C device.
+ //
+ I2cDeviceContext = NULL;
+ I2cDeviceContext = AllocateCopyPool (sizeof (I2C_DEVICE_CONTEXT), &gI2cDeviceContextTemplate);
+ ASSERT (I2cDeviceContext != NULL);
+ if (I2cDeviceContext == NULL) {
+ continue;
+ }
+
+ //
+ // Initialize the specific device context
+ //
+ I2cDeviceContext->I2cBusContext = I2cBusContext;
+ I2cDeviceContext->I2cDevice = Device;
+ I2cDeviceContext->I2cIo.DeviceGuid = Device->DeviceGuid;
+ I2cDeviceContext->I2cIo.DeviceIndex = Device->DeviceIndex;
+ I2cDeviceContext->I2cIo.HardwareRevision = Device->HardwareRevision;
+ I2cDeviceContext->I2cIo.I2cControllerCapabilities = I2cBusContext->I2cHost->I2cControllerCapabilities;
+
+ //
+ // Build the device path
+ //
+ Status = I2cBusDevicePathAppend (I2cDeviceContext, BuildControllerNode);
+ ASSERT_EFI_ERROR (Status);
+ if (EFI_ERROR (Status)) {
+ continue;
+ }
+
+ //
+ // Install the protocol
+ //
+ Status = gBS->InstallMultipleProtocolInterfaces (
+ &I2cDeviceContext->Handle,
+ &gEfiI2cIoProtocolGuid,
+ &I2cDeviceContext->I2cIo,
+ &gEfiDevicePathProtocolGuid,
+ I2cDeviceContext->DevicePath,
+ NULL );
+ if (EFI_ERROR (Status)) {
+ //
+ // Free resources for this I2C device
+ //
+ ReleaseI2cDeviceContext (I2cDeviceContext);
+ continue;
+ }
+
+ //
+ // Create the child handle
+ //
+ Status = gBS->OpenProtocol (
+ Controller,
+ &gEfiI2cHostProtocolGuid,
+ (VOID **) &I2cBusContext->I2cHost,
+ I2cBusContext->DriverBindingHandle,
+ I2cDeviceContext->Handle,
+ EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
+ );
+ if (EFI_ERROR (Status)) {
+ Status = gBS->UninstallMultipleProtocolInterfaces (
+ I2cDeviceContext->Handle,
+ &gEfiDevicePathProtocolGuid,
+ I2cDeviceContext->DevicePath,
+ &gEfiI2cIoProtocolGuid,
+ &I2cDeviceContext->I2cIo,
+ NULL
+ );
+ //
+ // Free resources for this I2C device
+ //
+ ReleaseI2cDeviceContext (I2cDeviceContext);
+ continue;
+ }
+
+ if (RemainingDevicePath != NULL) {
+ //
+ // Child has been created successfully
+ //
+ break;
+ }
+ }
+
+ return Status;
+}
+
+
+/**
+ Queue an I2C transaction for execution on the I2C device.
+
+ This routine must be called at or below TPL_NOTIFY. For synchronous
+ requests this routine must be called at or below TPL_CALLBACK.
+
+ This routine queues an I2C transaction to the I2C controller for
+ execution on the I2C bus.
+
+ When Event is NULL, QueueRequest() operates synchronously and returns
+ the I2C completion status as its return value.
+
+ When Event is not NULL, QueueRequest() synchronously returns EFI_SUCCESS
+ indicating that the asynchronous I2C transaction was queued. The values
+ above are returned in the buffer pointed to by I2cStatus upon the
+ completion of the I2C transaction when I2cStatus is not NULL.
+
+ The upper layer driver writer provides the following to the platform
+ vendor:
+
+ 1. Vendor specific GUID for the I2C part
+ 2. Guidance on proper construction of the slave address array when the
+ I2C device uses more than one slave address. The I2C bus protocol
+ uses the SlaveAddressIndex to perform relative to physical address
+ translation to access the blocks of hardware within the I2C device.
+
+ @param[in] This Pointer to an EFI_I2C_IO_PROTOCOL structure.
+ @param[in] SlaveAddressIndex Index value into an array of slave addresses
+ for the I2C device. The values in the array
+ are specified by the board designer, with the
+ third party I2C device driver writer providing
+ the slave address order.
+
+ For devices that have a single slave address,
+ this value must be zero. If the I2C device
+ uses more than one slave address then the
+ third party (upper level) I2C driver writer
+ needs to specify the order of entries in the
+ slave address array.
+
+ \ref ThirdPartyI2cDrivers "Third Party I2C
+ Drivers" section in I2cMaster.h.
+ @param[in] Event Event to signal for asynchronous transactions,
+ NULL for synchronous transactions
+ @param[in] RequestPacket Pointer to an EFI_I2C_REQUEST_PACKET structure
+ describing the I2C transaction
+ @param[out] I2cStatus Optional buffer to receive the I2C transaction
+ completion status
+
+ @retval EFI_SUCCESS The asynchronous transaction was successfully
+ queued when Event is not NULL.
+ @retval EFI_SUCCESS The transaction completed successfully when
+ Event is NULL.
+ @retval EFI_ABORTED The request did not complete because the driver
+ binding Stop() routine was called.
+ @retval EFI_BAD_BUFFER_SIZE The RequestPacket->LengthInBytes value is too
+ large.
+ @retval EFI_DEVICE_ERROR There was an I2C error (NACK) during the
+ transaction.
+ @retval EFI_INVALID_PARAMETER RequestPacket is NULL
+ @retval EFI_NOT_FOUND Reserved bit set in the SlaveAddress parameter
+ @retval EFI_NO_MAPPING The EFI_I2C_HOST_PROTOCOL could not set the
+ bus configuration required to access this I2C
+ device.
+ @retval EFI_NO_RESPONSE The I2C device is not responding to the slave
+ address selected by SlaveAddressIndex.
+ EFI_DEVICE_ERROR will be returned if the
+ controller cannot distinguish when the NACK
+ occurred.
+ @retval EFI_OUT_OF_RESOURCES Insufficient memory for I2C transaction
+ @retval EFI_UNSUPPORTED The controller does not support the requested
+ transaction.
+
+**/
+EFI_STATUS
+EFIAPI
+I2cBusQueueRequest (
+ IN CONST EFI_I2C_IO_PROTOCOL *This,
+ IN UINTN SlaveAddressIndex,
+ IN EFI_EVENT Event OPTIONAL,
+ IN EFI_I2C_REQUEST_PACKET *RequestPacket,
+ OUT EFI_STATUS *I2cStatus OPTIONAL
+ )
+{
+ CONST EFI_I2C_DEVICE *I2cDevice;
+ I2C_BUS_CONTEXT *I2cBusContext;
+ CONST EFI_I2C_HOST_PROTOCOL *I2cHost;
+ I2C_DEVICE_CONTEXT *I2cDeviceContext;
+ EFI_STATUS Status;
+
+ if (RequestPacket == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // Validate the I2C slave index
+ //
+ I2cDeviceContext = I2C_DEVICE_CONTEXT_FROM_PROTOCOL (This);
+ I2cDevice = I2cDeviceContext->I2cDevice;
+ if ( SlaveAddressIndex >= I2cDevice->SlaveAddressCount ) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // Locate the I2c Host Protocol to queue request
+ //
+ I2cBusContext = I2cDeviceContext->I2cBusContext;
+ I2cHost = I2cBusContext->I2cHost;
+
+ //
+ // Start the I2C operation
+ //
+ Status = I2cHost->QueueRequest (
+ I2cHost,
+ I2cDevice->I2cBusConfiguration,
+ I2cDevice->SlaveAddressArray [SlaveAddressIndex],
+ Event,
+ RequestPacket,
+ I2cStatus
+ );
+
+ return Status;
+}
+
+/**
+ Release all the resources allocated for the I2C device.
+
+ This function releases all the resources allocated for the I2C device.
+
+ @param I2cDeviceContext The I2C child device involved for the operation.
+
+**/
+VOID
+ReleaseI2cDeviceContext (
+ IN I2C_DEVICE_CONTEXT *I2cDeviceContext
+ )
+{
+ if (I2cDeviceContext == NULL) {
+ return;
+ }
+
+ if (I2cDeviceContext->DevicePath != NULL) {
+ FreePool (I2cDeviceContext->DevicePath);
+ }
+
+ FreePool (I2cDeviceContext);
+}
+
+/**
+ Unregister an I2C device.
+
+ This function removes the protocols installed on the controller handle and
+ frees the resources allocated for the I2C device.
+
+ @param This The pointer to EFI_DRIVER_BINDING_PROTOCOL instance.
+ @param Controller The controller handle of the I2C device.
+ @param Handle The child handle.
+
+ @retval EFI_SUCCESS The I2C device is successfully unregistered.
+ @return Others Some error occurs when unregistering the I2C device.
+
+**/
+EFI_STATUS
+UnRegisterI2cDevice (
+ IN EFI_DRIVER_BINDING_PROTOCOL *This,
+ IN EFI_HANDLE Controller,
+ IN EFI_HANDLE Handle
+ )
+{
+ EFI_STATUS Status;
+ I2C_DEVICE_CONTEXT *I2cDeviceContext;
+ EFI_I2C_IO_PROTOCOL *I2cIo;
+ EFI_I2C_HOST_PROTOCOL *I2cHost;
+
+ I2cIo = NULL;
+
+ Status = gBS->OpenProtocol (
+ Handle,
+ &gEfiI2cIoProtocolGuid,
+ (VOID **) &I2cIo,
+ This->DriverBindingHandle,
+ Controller,
+ EFI_OPEN_PROTOCOL_GET_PROTOCOL
+ );
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ //
+ // Get I2c device context data.
+ //
+ I2cDeviceContext = I2C_DEVICE_CONTEXT_FROM_PROTOCOL (I2cIo);
+
+ //
+ // Close the child handle
+ //
+ gBS->CloseProtocol (
+ Controller,
+ &gEfiI2cHostProtocolGuid,
+ This->DriverBindingHandle,
+ Handle
+ );
+
+ //
+ // The I2C Bus driver installs the I2C Io and Device Path Protocol in the DriverBindingStart().
+ // Here should uninstall them.
+ //
+ Status = gBS->UninstallMultipleProtocolInterfaces (
+ Handle,
+ &gEfiDevicePathProtocolGuid,
+ I2cDeviceContext->DevicePath,
+ &gEfiI2cIoProtocolGuid,
+ &I2cDeviceContext->I2cIo,
+ NULL
+ );
+
+ if (EFI_ERROR (Status)) {
+ //
+ // Keep parent and child relationship
+ //
+ gBS->OpenProtocol (
+ Controller,
+ &gEfiI2cHostProtocolGuid,
+ (VOID **) &I2cHost,
+ This->DriverBindingHandle,
+ Handle,
+ EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
+ );
+ return Status;
+ }
+
+ //
+ // Free resources for this I2C device
+ //
+ ReleaseI2cDeviceContext (I2cDeviceContext);
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Create a path for the I2C device
+
+ Append the I2C slave path to the I2C master controller path.
+
+ @param[in] I2cDeviceContext Address of an I2C_DEVICE_CONTEXT structure.
+ @param[in] BuildControllerNode Flag to build controller node in device path.
+
+ @retval EFI_SUCCESS The I2C device path is built successfully.
+ @return Others It is failed to built device path.
+
+**/
+EFI_STATUS
+I2cBusDevicePathAppend (
+ IN I2C_DEVICE_CONTEXT *I2cDeviceContext,
+ IN BOOLEAN BuildControllerNode
+ )
+{
+ EFI_DEVICE_PATH_PROTOCOL *PreviousDevicePath;
+
+ PreviousDevicePath = NULL;
+
+ //
+ // Build vendor device path
+ //
+ CopyMem (&gVendorDevicePathTemplate.Guid, I2cDeviceContext->I2cDevice->DeviceGuid, sizeof (EFI_GUID));
+ I2cDeviceContext->DevicePath = AppendDevicePathNode (
+ I2cDeviceContext->I2cBusContext->ParentDevicePath,
+ (EFI_DEVICE_PATH_PROTOCOL *) &gVendorDevicePathTemplate
+ );
+ ASSERT (I2cDeviceContext->DevicePath != NULL);
+ if (I2cDeviceContext->DevicePath == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ if ((BuildControllerNode) && (I2cDeviceContext->DevicePath != NULL)) {
+ //
+ // Build the final I2C device path with controller node
+ //
+ PreviousDevicePath = I2cDeviceContext->DevicePath;
+ gControllerDevicePathTemplate.ControllerNumber = I2cDeviceContext->I2cDevice->DeviceIndex;
+ I2cDeviceContext->DevicePath = AppendDevicePathNode (
+ I2cDeviceContext->DevicePath,
+ (EFI_DEVICE_PATH_PROTOCOL *) &gControllerDevicePathTemplate
+ );
+ gBS->FreePool (PreviousDevicePath);
+ ASSERT (I2cDeviceContext->DevicePath != NULL);
+ if (I2cDeviceContext->DevicePath == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ The user entry point for the I2C bus module. The user code starts with
+ this function.
+
+ @param[in] ImageHandle The firmware allocated handle for the EFI image.
+ @param[in] SystemTable A pointer to the EFI System Table.
+
+ @retval EFI_SUCCESS The entry point is executed successfully.
+ @retval other Some error occurs when executing this entry point.
+
+**/
+EFI_STATUS
+EFIAPI
+InitializeI2cBus(
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_STATUS Status;
+
+ //
+ // Install driver model protocol(s).
+ //
+ Status = EfiLibInstallDriverBindingComponentName2 (
+ ImageHandle,
+ SystemTable,
+ &gI2cBusDriverBinding,
+ NULL,
+ &gI2cBusComponentName,
+ &gI2cBusComponentName2
+ );
+ ASSERT_EFI_ERROR (Status);
+
+
+ return Status;
+}
+
+/**
+ This is the unload handle for I2C bus module.
+
+ Disconnect the driver specified by ImageHandle from all the devices in the handle database.
+ Uninstall all the protocols installed in the driver entry point.
+
+ @param[in] ImageHandle The drivers' driver image.
+
+ @retval EFI_SUCCESS The image is unloaded.
+ @retval Others Failed to unload the image.
+
+**/
+EFI_STATUS
+EFIAPI
+I2cBusUnload (
+ IN EFI_HANDLE ImageHandle
+ )
+{
+ EFI_STATUS Status;
+ EFI_HANDLE *DeviceHandleBuffer;
+ UINTN DeviceHandleCount;
+ UINTN Index;
+
+ //
+ // Get the list of all I2C Controller handles in the handle database.
+ // If there is an error getting the list, then the unload
+ // operation fails.
+ //
+ Status = gBS->LocateHandleBuffer (
+ ByProtocol,
+ &gEfiI2cHostProtocolGuid,
+ NULL,
+ &DeviceHandleCount,
+ &DeviceHandleBuffer
+ );
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ //
+ // Disconnect the driver specified by Driver BindingHandle from all
+ // the devices in the handle database.
+ //
+ for (Index = 0; Index < DeviceHandleCount; Index++) {
+ Status = gBS->DisconnectController (
+ DeviceHandleBuffer[Index],
+ gI2cBusDriverBinding.DriverBindingHandle,
+ NULL
+ );
+ if (EFI_ERROR (Status)) {
+ goto Done;
+ }
+ }
+
+ //
+ // Uninstall all the protocols installed in the driver entry point
+ //
+ Status = gBS->UninstallMultipleProtocolInterfaces (
+ gI2cBusDriverBinding.DriverBindingHandle,
+ &gEfiDriverBindingProtocolGuid,
+ &gI2cBusDriverBinding,
+ &gEfiComponentNameProtocolGuid,
+ &gI2cBusComponentName,
+ &gEfiComponentName2ProtocolGuid,
+ &gI2cBusComponentName2,
+ NULL
+ );
+ ASSERT_EFI_ERROR (Status);
+
+Done:
+ //
+ // Free the buffer containing the list of handles from the handle database
+ //
+ if (DeviceHandleBuffer != NULL) {
+ gBS->FreePool (DeviceHandleBuffer);
+ }
+
+ return Status;
+}
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