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audk/MdeModulePkg/Bus/I2c/I2cDxe/I2cHost.c

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/** @file
This file implements I2C Host Protocol which provides callers with the ability to
do I/O transactions to all of the devices on the I2C bus.
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 gI2cHostDriverBinding = {
I2cHostDriverSupported,
I2cHostDriverStart,
I2cHostDriverStop,
0x10,
NULL,
NULL
};
//
// Driver name table
//
GLOBAL_REMOVE_IF_UNREFERENCED EFI_UNICODE_STRING_TABLE mI2cHostDriverNameTable[] = {
{ "eng;en", L"I2c Host Driver" },
{ NULL , NULL }
};
//
// EFI Component Name Protocol
//
GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME_PROTOCOL gI2cHostComponentName = {
(EFI_COMPONENT_NAME_GET_DRIVER_NAME) I2cHostComponentNameGetDriverName,
(EFI_COMPONENT_NAME_GET_CONTROLLER_NAME) I2cHostComponentNameGetControllerName,
"eng"
};
//
// EFI Component Name 2 Protocol
//
GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME2_PROTOCOL gI2cHostComponentName2 = {
I2cHostComponentNameGetDriverName,
I2cHostComponentNameGetControllerName,
"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
I2cHostComponentNameGetDriverName (
IN EFI_COMPONENT_NAME2_PROTOCOL *This,
IN CHAR8 *Language,
OUT CHAR16 **DriverName
)
{
return LookupUnicodeString2 (
Language,
This->SupportedLanguages,
mI2cHostDriverNameTable,
DriverName,
(BOOLEAN)(This != &gI2cHostComponentName2)
);
}
/**
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
I2cHostComponentNameGetControllerName (
IN EFI_COMPONENT_NAME2_PROTOCOL *This,
IN EFI_HANDLE ControllerHandle,
IN EFI_HANDLE ChildHandle OPTIONAL,
IN CHAR8 *Language,
OUT CHAR16 **ControllerName
)
{
return EFI_UNSUPPORTED;
}
/**
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
I2cHostDriverSupported (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE Controller,
IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
)
{
EFI_I2C_MASTER_PROTOCOL *I2cMaster;
EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL *I2cBusConfigurationManagement;
EFI_STATUS Status;
//
// Locate I2C Bus Configuration Management Protocol
//
Status = gBS->OpenProtocol (
Controller,
&gEfiI2cBusConfigurationManagementProtocolGuid,
(VOID **)&I2cBusConfigurationManagement,
This->DriverBindingHandle,
Controller,
EFI_OPEN_PROTOCOL_BY_DRIVER
);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Close the protocol because we don't use it here
//
gBS->CloseProtocol (
Controller,
&gEfiI2cBusConfigurationManagementProtocolGuid,
This->DriverBindingHandle,
Controller
);
//
// Locate I2C Master Protocol
//
Status = gBS->OpenProtocol (
Controller,
&gEfiI2cMasterProtocolGuid,
(VOID **)&I2cMaster,
This->DriverBindingHandle,
Controller,
EFI_OPEN_PROTOCOL_GET_PROTOCOL
);
if (EFI_ERROR (Status)) {
return Status;
}
return EFI_SUCCESS;
}
/**
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
I2cHostDriverStart (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE Controller,
IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
)
{
EFI_STATUS Status;
EFI_I2C_MASTER_PROTOCOL *I2cMaster;
EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL *I2cBusConfigurationManagement;
I2C_HOST_CONTEXT *I2cHostContext;
I2cMaster = NULL;
I2cHostContext = NULL;
I2cBusConfigurationManagement = NULL;
//
// Locate I2C Bus Configuration Management Protocol
//
Status = gBS->OpenProtocol (
Controller,
&gEfiI2cBusConfigurationManagementProtocolGuid,
(VOID **)&I2cBusConfigurationManagement,
This->DriverBindingHandle,
Controller,
EFI_OPEN_PROTOCOL_BY_DRIVER
);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "I2cHost: Open I2C bus configuration error, Status = %r\n", Status));
return Status;
}
//
// Locate I2C Master Protocol
//
Status = gBS->OpenProtocol (
Controller,
&gEfiI2cMasterProtocolGuid,
(VOID **)&I2cMaster,
This->DriverBindingHandle,
Controller,
EFI_OPEN_PROTOCOL_GET_PROTOCOL
);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "I2cHost: Open I2C master error, Status = %r\n", Status));
goto Exit;
}
//
// Allocate the I2C Host Context structure
//
I2cHostContext = AllocateZeroPool (sizeof (I2C_HOST_CONTEXT));
if (I2cHostContext == NULL) {
DEBUG ((EFI_D_ERROR, "I2cHost: there is no enough memory to allocate.\n"));
Status = EFI_OUT_OF_RESOURCES;
goto Exit;
}
//
// Initialize the context structure for the current I2C Controller
//
I2cHostContext->Signature = I2C_HOST_SIGNATURE;
I2cHostContext->I2cMaster = I2cMaster;
I2cHostContext->I2cBusConfigurationManagement = I2cBusConfigurationManagement;
I2cHostContext->I2cBusConfiguration = (UINTN) -1;
InitializeListHead(&I2cHostContext->RequestList);
//
// Reset the controller
//
Status = I2cMaster->Reset (I2cMaster);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "I2cHost: I2C controller reset failed!\n"));
goto Exit;
}
//
// Create the I2C transaction complete event
//
Status = gBS->CreateEvent (
EVT_NOTIFY_SIGNAL,
TPL_I2C_SYNC,
I2cHostRequestCompleteEvent,
I2cHostContext,
&I2cHostContext->I2cEvent
);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "I2cHost: create complete event error, Status = %r\n", Status));
goto Exit;
}
//
// Get the bus management event
//
Status = gBS->CreateEvent (
EVT_NOTIFY_SIGNAL,
TPL_I2C_SYNC,
I2cHostI2cBusConfigurationAvailable,
I2cHostContext,
&I2cHostContext->I2cBusConfigurationEvent
);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "I2cHost: create bus available event error, Status = %r\n", Status));
goto Exit;
}
//
// Build the I2C host protocol for the current I2C controller
//
I2cHostContext->I2cHost.QueueRequest = I2cHostQueueRequest;
I2cHostContext->I2cHost.I2cControllerCapabilities = I2cMaster->I2cControllerCapabilities;
//
// Install the driver protocol
//
Status = gBS->InstallMultipleProtocolInterfaces (
&Controller,
&gEfiI2cHostProtocolGuid,
&I2cHostContext->I2cHost,
NULL
);
Exit:
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "I2cHost: Start() function failed, Status = %r\n", Status));
if (I2cBusConfigurationManagement != NULL) {
gBS->CloseProtocol (
Controller,
&gEfiI2cBusConfigurationManagementProtocolGuid,
This->DriverBindingHandle,
Controller
);
}
if ((I2cHostContext != NULL) && (I2cHostContext->I2cEvent != NULL)) {
gBS->CloseEvent (I2cHostContext->I2cEvent);
I2cHostContext->I2cEvent = NULL;
}
if ((I2cHostContext != NULL) && (I2cHostContext->I2cBusConfigurationEvent != NULL)) {
gBS->CloseEvent (I2cHostContext->I2cBusConfigurationEvent);
I2cHostContext->I2cBusConfigurationEvent = NULL;
}
//
// Release the context structure upon failure
//
if (I2cHostContext != NULL) {
FreePool (I2cHostContext);
}
}
//
// 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
I2cHostDriverStop (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE Controller,
IN UINTN NumberOfChildren,
IN EFI_HANDLE *ChildHandleBuffer
)
{
EFI_STATUS Status;
I2C_HOST_CONTEXT *I2cHostContext;
EFI_I2C_HOST_PROTOCOL *I2cHost;
EFI_TPL TplPrevious;
TplPrevious = EfiGetCurrentTpl ();
if (TplPrevious > TPL_I2C_SYNC) {
DEBUG ((EFI_D_ERROR, "I2cHost: TPL %d is too high in Stop.\n", TplPrevious));
return EFI_DEVICE_ERROR;
}
Status = gBS->OpenProtocol (
Controller,
&gEfiI2cHostProtocolGuid,
(VOID **) &I2cHost,
This->DriverBindingHandle,
Controller,
EFI_OPEN_PROTOCOL_GET_PROTOCOL
);
if (EFI_ERROR (Status)) {
return EFI_DEVICE_ERROR;
}
I2cHostContext = I2C_HOST_CONTEXT_FROM_PROTOCOL (I2cHost);
//
// Raise TPL for critical section
//
TplPrevious = gBS->RaiseTPL (TPL_I2C_SYNC);
//
// If there is pending request or pending bus configuration, do not stop
//
Status = EFI_DEVICE_ERROR;
if (( !I2cHostContext->I2cBusConfigurationManagementPending )
&& IsListEmpty (&I2cHostContext->RequestList)) {
//
// Remove the I2C host protocol
//
Status = gBS->UninstallMultipleProtocolInterfaces (
Controller,
&gEfiI2cHostProtocolGuid,
I2cHost,
NULL
);
}
//
// Leave critical section
//
gBS->RestoreTPL (TplPrevious);
if (!EFI_ERROR (Status)) {
gBS->CloseProtocol (
Controller,
&gEfiI2cBusConfigurationManagementProtocolGuid,
This->DriverBindingHandle,
Controller
);
//
// Release I2c Host resources
//
if (I2cHostContext->I2cBusConfigurationEvent != NULL) {
gBS->CloseEvent (I2cHostContext->I2cBusConfigurationEvent);
I2cHostContext->I2cBusConfigurationEvent = NULL;
}
if (I2cHostContext->I2cEvent != NULL) {
gBS->CloseEvent (I2cHostContext->I2cEvent);
I2cHostContext->I2cEvent = NULL;
}
FreePool (I2cHostContext);
}
//
// Return the stop status
//
return Status;
}
/**
Handle the I2C bus configuration available event
This routine is called at TPL_I2C_SYNC.
@param[in] Event Address of an EFI_EVENT handle
@param[in] Context Address of an I2C_HOST_CONTEXT structure
**/
VOID
EFIAPI
I2cHostI2cBusConfigurationAvailable (
IN EFI_EVENT Event,
IN VOID *Context
)
{
I2C_HOST_CONTEXT *I2cHostContext;
EFI_I2C_MASTER_PROTOCOL *I2cMaster;
I2C_REQUEST *I2cRequest;
LIST_ENTRY *EntryHeader;
LIST_ENTRY *Entry;
EFI_STATUS Status;
//
// Mark this I2C bus configuration management operation as complete
//
I2cHostContext = (I2C_HOST_CONTEXT *)Context;
I2cMaster = I2cHostContext->I2cMaster;
ASSERT (I2cMaster != NULL);
//
// Clear flag to indicate I2C bus configuration is finished
//
I2cHostContext->I2cBusConfigurationManagementPending = FALSE;
//
// Validate the completion status
//
if (EFI_ERROR (I2cHostContext->Status)) {
//
// Setting I2C bus configuration failed before
//
I2cHostRequestComplete (I2cHostContext, I2cHostContext->Status);
//
// Unknown I2C bus configuration
// Force next operation to enable the I2C bus configuration
//
I2cHostContext->I2cBusConfiguration = (UINTN) -1;
//
// Do not continue current I2C request
//
return;
}
//
// Get the first request in the link with FIFO order
//
EntryHeader = &I2cHostContext->RequestList;
Entry = GetFirstNode (EntryHeader);
I2cRequest = I2C_REQUEST_FROM_ENTRY (Entry);
//
// Update the I2C bus configuration of the current I2C request
//
I2cHostContext->I2cBusConfiguration = I2cRequest->I2cBusConfiguration;
//
// Start an I2C operation on the host, the status is returned by I2cHostContext->Status
//
Status = I2cMaster->StartRequest (
I2cMaster,
I2cRequest->SlaveAddress,
I2cRequest->RequestPacket,
I2cHostContext->I2cEvent,
&I2cHostContext->Status
);
}
/**
Complete the current request
This routine is called at TPL_I2C_SYNC.
@param[in] I2cHostContext Address of an I2C_HOST_CONTEXT structure.
@param[in] Status Status of the I2C operation.
@return This routine returns the input status value.
**/
EFI_STATUS
I2cHostRequestComplete (
I2C_HOST_CONTEXT *I2cHostContext,
EFI_STATUS Status
)
{
I2C_REQUEST *I2cRequest;
LIST_ENTRY *EntryHeader;
LIST_ENTRY *Entry;
//
// Remove the current I2C request from the list
//
EntryHeader = &I2cHostContext->RequestList;
Entry = GetFirstNode (EntryHeader);
I2cRequest = I2C_REQUEST_FROM_ENTRY (Entry);
//
// Save the status for QueueRequest
//
if ( NULL != I2cRequest->Status ) {
*I2cRequest->Status = Status;
}
//
// Notify the user of the I2C request completion
//
if ( NULL != I2cRequest->Event ) {
gBS->SignalEvent (I2cRequest->Event);
}
//
// Done with this request, remove the current request from list
//
RemoveEntryList (&I2cRequest->Link);
FreePool (I2cRequest->RequestPacket);
FreePool (I2cRequest);
//
// If there is more I2C request, start next one
//
if(!IsListEmpty (EntryHeader)) {
I2cHostRequestEnable (I2cHostContext);
}
return Status;
}
/**
Handle the bus available event
This routine is called at TPL_I2C_SYNC.
@param[in] Event Address of an EFI_EVENT handle
@param[in] Context Address of an I2C_HOST_CONTEXT structure
**/
VOID
EFIAPI
I2cHostRequestCompleteEvent (
IN EFI_EVENT Event,
IN VOID *Context
)
{
I2C_HOST_CONTEXT *I2cHostContext;
//
// Handle the completion event
//
I2cHostContext = (I2C_HOST_CONTEXT *)Context;
I2cHostRequestComplete (I2cHostContext, I2cHostContext->Status);
}
/**
Enable access to the I2C bus configuration
@param[in] I2cHostContext Address of an I2C_HOST_CONTEXT structure
@retval EFI_SUCCESS The operation completed successfully.
@retval EFI_ABORTED The request did not complete because the driver
was shutdown.
@retval EFI_BAD_BUFFER_SIZE The WriteBytes or ReadBytes buffer size is too large.
@retval EFI_DEVICE_ERROR There was an I2C error (NACK) during the operation.
This could indicate the slave device is not present.
@retval EFI_INVALID_PARAMETER RequestPacket is NULL
@retval EFI_NO_MAPPING Invalid I2cBusConfiguration value
@retval EFI_NO_RESPONSE The I2C device is not responding to the
slave address. EFI_DEVICE_ERROR may also be
returned if the controller can not distinguish
when the NACK occurred.
@retval EFI_NOT_FOUND I2C slave address exceeds maximum address
@retval EFI_NOT_READY I2C bus is busy or operation pending, wait for
the event and then read status.
@retval EFI_OUT_OF_RESOURCES Insufficient memory for I2C operation
@retval EFI_TIMEOUT The transaction did not complete within an internally
specified timeout period.
**/
EFI_STATUS
I2cHostRequestEnable (
I2C_HOST_CONTEXT *I2cHostContext
)
{
UINTN I2cBusConfiguration;
CONST EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL *I2cBusConfigurationManagement;
I2C_REQUEST *I2cRequest;
EFI_STATUS Status;
EFI_TPL TplPrevious;
LIST_ENTRY *EntryHeader;
LIST_ENTRY *Entry;
//
// Assume pending request
//
Status = EFI_NOT_READY;
I2cBusConfigurationManagement = I2cHostContext->I2cBusConfigurationManagement;
//
// Validate the I2c bus configuration
//
EntryHeader = &I2cHostContext->RequestList;
Entry = GetFirstNode (EntryHeader);
I2cRequest = I2C_REQUEST_FROM_ENTRY (Entry);
I2cBusConfiguration = I2cRequest->I2cBusConfiguration;
if (I2cHostContext->I2cBusConfiguration != I2cBusConfiguration ) {
//
// Set flag to indicate I2C bus configuration is in progress
//
I2cHostContext->I2cBusConfigurationManagementPending = TRUE;
//
// Update bus configuration for this device's requesting bus configuration
//
Status = I2cBusConfigurationManagement->EnableI2cBusConfiguration (
I2cBusConfigurationManagement,
I2cBusConfiguration,
I2cHostContext->I2cBusConfigurationEvent,
&I2cHostContext->Status
);
} else {
//
// I2C bus configuration is same, no need change configuration and start I2c transaction directly
//
TplPrevious = gBS->RaiseTPL ( TPL_I2C_SYNC );
//
// Same I2C bus configuration
//
I2cHostContext->Status = EFI_SUCCESS;
I2cHostI2cBusConfigurationAvailable (I2cHostContext->I2cBusConfigurationEvent, I2cHostContext);
//
// Release the thread synchronization
//
gBS->RestoreTPL ( TplPrevious );
}
return Status;
}
/**
Queue an I2C operation for execution on the I2C controller.
This routine must be called at or below TPL_NOTIFY. For synchronous
requests this routine must be called at or below TPL_CALLBACK.
N.B. The typical consumers of this API are the I2C bus driver and
on rare occasions the I2C test application. Extreme care must be
taken by other consumers of this API to prevent confusing the
third party I2C drivers due to a state change at the I2C device
which the third party I2C drivers did not initiate. I2C platform
drivers may use this API within these guidelines.
This layer uses the concept of I2C bus configurations to describe
the I2C bus. An I2C bus configuration is defined as a unique
setting of the multiplexers and switches in the I2C bus which
enable access to one or more I2C devices. When using a switch
to divide a bus, due to speed differences, the I2C platform layer
would define an I2C bus configuration for the I2C devices on each
side of the switch. When using a multiplexer, the I2C platform
layer defines an I2C bus configuration for each of the selector
values required to control the multiplexer. See Figure 1 in the
<a href="http://www.nxp.com/documents/user_manual/UM10204.pdf">I<sup>2</sup>C
Specification</a> for a complex I2C bus configuration.
The I2C host driver processes all operations in FIFO order. Prior to
performing the operation, the I2C host driver calls the I2C platform
driver to reconfigure the switches and multiplexers in the I2C bus
enabling access to the specified I2C device. The I2C platform driver
also selects the maximum bus speed for the device. After the I2C bus
is configured, the I2C host driver calls the I2C port driver to
initialize the I2C controller and start the I2C operation.
@param[in] This Address of an EFI_I2C_HOST_PROTOCOL instance.
@param[in] I2cBusConfiguration I2C bus configuration to access the I2C
device.
@param[in] SlaveAddress Address of the device on the I2C bus.
@param[in] Event Event to set for asynchronous operations,
NULL for synchronous operations
@param[in] RequestPacket Address of an EFI_I2C_REQUEST_PACKET
structure describing the I2C operation
@param[out] I2cStatus Optional buffer to receive the I2C operation
completion status
@retval EFI_SUCCESS The operation completed successfully.
@retval EFI_ABORTED The request did not complete because the driver
was shutdown.
@retval EFI_BAD_BUFFER_SIZE The WriteBytes or ReadBytes buffer size is too large.
@retval EFI_DEVICE_ERROR There was an I2C error (NACK) during the operation.
This could indicate the slave device is not present.
@retval EFI_INVALID_PARAMETER RequestPacket is NULL
@retval EFI_INVALID_PARAMETER TPL is too high
@retval EFI_NO_MAPPING Invalid I2cBusConfiguration value
@retval EFI_NO_RESPONSE The I2C device is not responding to the
slave address. EFI_DEVICE_ERROR may also be
returned if the controller can not distinguish
when the NACK occurred.
@retval EFI_NOT_FOUND I2C slave address exceeds maximum address
@retval EFI_NOT_READY I2C bus is busy or operation pending, wait for
the event and then read status pointed to by
the request packet.
@retval EFI_OUT_OF_RESOURCES Insufficient memory for I2C operation
@retval EFI_TIMEOUT The transaction did not complete within an internally
specified timeout period.
**/
EFI_STATUS
EFIAPI
I2cHostQueueRequest (
IN CONST EFI_I2C_HOST_PROTOCOL *This,
IN UINTN I2cBusConfiguration,
IN UINTN SlaveAddress,
IN EFI_EVENT Event OPTIONAL,
IN EFI_I2C_REQUEST_PACKET *RequestPacket,
OUT EFI_STATUS *I2cStatus OPTIONAL
)
{
EFI_STATUS Status;
EFI_EVENT SyncEvent;
EFI_TPL TplPrevious;
I2C_REQUEST *I2cRequest;
I2C_HOST_CONTEXT *I2cHostContext;
BOOLEAN FirstRequest;
UINTN RequestPacketSize;
SyncEvent = NULL;
FirstRequest = FALSE;
Status = EFI_SUCCESS;
if (RequestPacket == NULL) {
return EFI_INVALID_PARAMETER;
}
I2cHostContext = I2C_HOST_CONTEXT_FROM_PROTOCOL (This);
if (Event == NULL) {
//
// For synchronous transaction, register an event used to wait for finishing synchronous transaction
//
Status = gBS->CreateEvent (
0,
TPL_I2C_SYNC,
NULL,
NULL,
&SyncEvent
);
if (EFI_ERROR (Status)) {
return Status;
}
}
//
// TPL should be at or below TPL_NOTIFY.
// For synchronous requests this routine must be called at or below TPL_CALLBACK.
//
TplPrevious = EfiGetCurrentTpl ();
if ((TplPrevious > TPL_I2C_SYNC) || ((Event == NULL) && (TplPrevious > TPL_CALLBACK))) {
DEBUG ((EFI_D_ERROR, "ERROR - TPL %d is too high!\n", TplPrevious));
return EFI_INVALID_PARAMETER;
}
//
// Allocate the request structure
//
I2cRequest = AllocateZeroPool (sizeof (I2C_REQUEST));
if (I2cRequest == NULL) {
DEBUG ((EFI_D_ERROR, "WARNING - Failed to allocate I2C_REQUEST!\n"));
return EFI_OUT_OF_RESOURCES;
}
//
// Initialize the request
//
I2cRequest->Signature = I2C_REQUEST_SIGNATURE;
I2cRequest->I2cBusConfiguration = I2cBusConfiguration;
I2cRequest->SlaveAddress = SlaveAddress;
I2cRequest->Event = (Event == NULL) ? SyncEvent : Event;
I2cRequest->Status = I2cStatus;
//
// Copy request packet into private buffer, as RequestPacket may be freed during asynchronous transaction
//
RequestPacketSize = sizeof (UINTN) + RequestPacket->OperationCount * sizeof (EFI_I2C_OPERATION);
I2cRequest->RequestPacket = AllocateZeroPool (RequestPacketSize);
CopyMem (I2cRequest->RequestPacket, RequestPacket, RequestPacketSize);
//
// Synchronize with the other threads
//
gBS->RaiseTPL ( TPL_I2C_SYNC );
FirstRequest = IsListEmpty (&I2cHostContext->RequestList);
//
// Insert new I2C request in the list
//
InsertTailList (&I2cHostContext->RequestList, &I2cRequest->Link);
//
// Release the thread synchronization
//
gBS->RestoreTPL (TplPrevious);
if (FirstRequest) {
//
// Start the first I2C request, then the subsequent of I2C request will continue
//
Status = I2cHostRequestEnable (I2cHostContext);
}
if (Event != NULL) {
//
// For asynchronous, return EFI_SUCCESS indicating that the asynchronously I2C transaction was queued.
// No real I2C operation status in I2cStatus
//
return EFI_SUCCESS;
}
//
// For synchronous transaction, wait for the operation completion
//
do {
Status = gBS->CheckEvent (SyncEvent);
} while (Status == EFI_NOT_READY);
//
// Get the I2C operation status
//
Status = I2cHostContext->Status;
//
// Return the I2C operation status
//
if (I2cStatus != NULL) {
*I2cStatus = Status;
}
//
// Close the event if necessary
//
if (SyncEvent != NULL) {
gBS->CloseEvent (SyncEvent);
}
return Status;
}
/**
The user Entry Point for I2C host 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
InitializeI2cHost(
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
//
// Install driver model protocol(s).
//
Status = EfiLibInstallDriverBindingComponentName2 (
ImageHandle,
SystemTable,
&gI2cHostDriverBinding,
ImageHandle,
&gI2cHostComponentName,
&gI2cHostComponentName2
);
ASSERT_EFI_ERROR (Status);
return Status;
}
/**
This is the unload handle for I2C host 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
I2cHostUnload (
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 ImageHandle from all
// the devices in the handle database.
//
for (Index = 0; Index < DeviceHandleCount; Index++) {
Status = gBS->DisconnectController (
DeviceHandleBuffer[Index],
ImageHandle,
NULL
);
if (EFI_ERROR (Status)) {
goto Done;
}
}
//
// Uninstall all the protocols installed in the driver entry point
//
Status = gBS->UninstallMultipleProtocolInterfaces (
gI2cHostDriverBinding.DriverBindingHandle,
&gEfiDriverBindingProtocolGuid,
&gI2cHostDriverBinding,
&gEfiComponentNameProtocolGuid,
&gI2cHostComponentName,
&gEfiComponentName2ProtocolGuid,
&gI2cHostComponentName2,
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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