TianoCore EDK2 master
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#include <Uefi.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/DevicePathLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/TimerLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/UefiLib.h>
#include <Protocol/DriverBinding.h>
#include <Protocol/I2cEnumerate.h>
#include <Protocol/I2cHost.h>
#include <Protocol/I2cIo.h>
#include <Protocol/I2cMaster.h>
#include <Protocol/I2cBusConfigurationManagement.h>
#include <Protocol/LoadedImage.h>
Go to the source code of this file.
Data Structures | |
struct | I2C_BUS_CONTEXT |
struct | I2C_DEVICE_CONTEXT |
struct | I2C_REQUEST |
struct | I2C_HOST_CONTEXT |
Macros | |
#define | I2C_DEVICE_SIGNATURE SIGNATURE_32 ('I', '2', 'C', 'D') |
#define | I2C_HOST_SIGNATURE SIGNATURE_32 ('I', '2', 'C', 'H') |
#define | I2C_REQUEST_SIGNATURE SIGNATURE_32 ('I', '2', 'C', 'R') |
#define | TPL_I2C_SYNC TPL_NOTIFY |
#define | I2C_DEVICE_CONTEXT_FROM_PROTOCOL(a) CR (a, I2C_DEVICE_CONTEXT, I2cIo, I2C_DEVICE_SIGNATURE) |
#define | I2C_REQUEST_FROM_ENTRY(a) CR (a, I2C_REQUEST, Link, I2C_REQUEST_SIGNATURE); |
#define | I2C_HOST_CONTEXT_FROM_PROTOCOL(a) CR (a, I2C_HOST_CONTEXT, I2cHost, I2C_HOST_SIGNATURE) |
Private data structures for the I2C DXE driver.
This file defines common data structures, macro definitions and some module internal function header files.
Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent
Definition in file I2cDxe.h.
#define I2C_DEVICE_CONTEXT_FROM_PROTOCOL | ( | a | ) | CR (a, I2C_DEVICE_CONTEXT, I2cIo, I2C_DEVICE_SIGNATURE) |
#define I2C_DEVICE_SIGNATURE SIGNATURE_32 ('I', '2', 'C', 'D') |
#define I2C_HOST_CONTEXT_FROM_PROTOCOL | ( | a | ) | CR (a, I2C_HOST_CONTEXT, I2cHost, I2C_HOST_SIGNATURE) |
#define I2C_HOST_SIGNATURE SIGNATURE_32 ('I', '2', 'C', 'H') |
#define I2C_REQUEST_FROM_ENTRY | ( | a | ) | CR (a, I2C_REQUEST, Link, I2C_REQUEST_SIGNATURE); |
#define I2C_REQUEST_SIGNATURE SIGNATURE_32 ('I', '2', 'C', 'R') |
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 | ||
) |
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.
This[in] | A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or EFI_COMPONENT_NAME_PROTOCOL instance. |
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. |
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. |
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. |
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. |
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. |
EFI_INVALID_PARAMETER | ControllerHandle is NULL. |
EFI_INVALID_PARAMETER | ChildHandle is not NULL and it is not a valid EFI_HANDLE. |
EFI_INVALID_PARAMETER | Language is NULL. |
EFI_INVALID_PARAMETER | ControllerName is NULL. |
EFI_UNSUPPORTED | The driver specified by This is not currently managing the controller specified by ControllerHandle and ChildHandle. |
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 | ||
) |
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.
This[in] | A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or EFI_COMPONENT_NAME_PROTOCOL instance. |
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. |
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. |
EFI_SUCCESS | The Unicode string for the Driver specified by This and the language specified by Language was returned in DriverName. |
EFI_INVALID_PARAMETER | Language is NULL. |
EFI_INVALID_PARAMETER | DriverName is NULL. |
EFI_UNSUPPORTED | The driver specified by This does not support the language specified by Language. |
EFI_STATUS I2cBusDevicePathAppend | ( | IN I2C_DEVICE_CONTEXT * | I2cDeviceContext, |
IN BOOLEAN | BuildControllerNode | ||
) |
Create a path for the I2C device
Append the I2C slave path to the I2C master controller path.
[in] | I2cDeviceContext | Address of an I2C_DEVICE_CONTEXT structure. |
[in] | BuildControllerNode | Flag to build controller node in device path. |
EFI_SUCCESS | The I2C device path is built successfully. |
EFI_STATUS EFIAPI I2cBusDriverStart | ( | IN EFI_DRIVER_BINDING_PROTOCOL * | This, |
IN EFI_HANDLE | Controller, | ||
IN EFI_DEVICE_PATH_PROTOCOL * | RemainingDevicePath | ||
) |
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.
[in] | This | A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance. |
[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. |
[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. |
EFI_SUCCESS | The device was started. |
EFI_DEVICE_ERROR | The device could not be started due to a device error.Currently not implemented. |
EFI_OUT_OF_RESOURCES | The request could not be completed due to a lack of resources. |
Others | The driver failed to start the device. |
EFI_STATUS EFIAPI I2cBusDriverStop | ( | IN EFI_DRIVER_BINDING_PROTOCOL * | This, |
IN EFI_HANDLE | Controller, | ||
IN UINTN | NumberOfChildren, | ||
IN EFI_HANDLE * | ChildHandleBuffer | ||
) |
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.
[in] | This | A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance. |
[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. |
[in] | NumberOfChildren | The number of child device handles in ChildHandleBuffer. |
[in] | ChildHandleBuffer | An array of child handles to be freed. May be NULL if NumberOfChildren is 0. |
EFI_SUCCESS | The device was stopped. |
EFI_DEVICE_ERROR | The device could not be stopped due to a device error. |
EFI_STATUS EFIAPI I2cBusDriverSupported | ( | IN EFI_DRIVER_BINDING_PROTOCOL * | This, |
IN EFI_HANDLE | Controller, | ||
IN EFI_DEVICE_PATH_PROTOCOL * | RemainingDevicePath | ||
) |
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.
[in] | This | A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance. |
[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. |
[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. |
EFI_SUCCESS | The device specified by ControllerHandle and RemainingDevicePath is supported by the driver specified by This. |
EFI_ALREADY_STARTED | The device specified by ControllerHandle and RemainingDevicePath is already being managed by the driver specified by This. |
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. |
EFI_UNSUPPORTED | The device specified by ControllerHandle and RemainingDevicePath is not supported by the driver specified by This. |
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 | ||
) |
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:
[in] | This | Pointer to an EFI_I2C_IO_PROTOCOL structure. |
[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.
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. 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.
[in] | Event | Event to signal for asynchronous transactions, NULL for synchronous transactions |
[in] | RequestPacket | Pointer to an EFI_I2C_REQUEST_PACKET structure describing the I2C transaction |
[out] | I2cStatus | Optional buffer to receive the I2C transaction completion status |
EFI_SUCCESS | The asynchronous transaction was successfully queued when Event is not NULL. |
EFI_SUCCESS | The transaction completed successfully when Event is NULL. |
EFI_BAD_BUFFER_SIZE | The RequestPacket->LengthInBytes value is too large. |
EFI_DEVICE_ERROR | There was an I2C error (NACK) during the transaction. |
EFI_INVALID_PARAMETER | RequestPacket is NULL |
EFI_NO_MAPPING | The EFI_I2C_HOST_PROTOCOL could not set the bus configuration required to access this I2C device. |
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. |
EFI_OUT_OF_RESOURCES | Insufficient memory for I2C transaction |
EFI_UNSUPPORTED | The controller does not support the requested transaction. |
EFI_STATUS EFIAPI I2cBusUnload | ( | IN EFI_HANDLE | ImageHandle | ) |
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.
[in] | ImageHandle | The drivers' driver image. |
EFI_SUCCESS | The image is unloaded. |
Others | Failed to unload the image. |
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 | ||
) |
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.
This[in] | A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or EFI_COMPONENT_NAME_PROTOCOL instance. |
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. |
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. |
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. |
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. |
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. |
EFI_INVALID_PARAMETER | ControllerHandle is NULL. |
EFI_INVALID_PARAMETER | ChildHandle is not NULL and it is not a valid EFI_HANDLE. |
EFI_INVALID_PARAMETER | Language is NULL. |
EFI_INVALID_PARAMETER | ControllerName is NULL. |
EFI_UNSUPPORTED | The driver specified by This is not currently managing the controller specified by ControllerHandle and ChildHandle. |
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 | ||
) |
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.
This[in] | A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or EFI_COMPONENT_NAME_PROTOCOL instance. |
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. |
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. |
EFI_SUCCESS | The Unicode string for the Driver specified by This and the language specified by Language was returned in DriverName. |
EFI_INVALID_PARAMETER | Language is NULL. |
EFI_INVALID_PARAMETER | DriverName is NULL. |
EFI_UNSUPPORTED | The driver specified by This does not support the language specified by Language. |
EFI_STATUS EFIAPI I2cHostDriverStart | ( | IN EFI_DRIVER_BINDING_PROTOCOL * | This, |
IN EFI_HANDLE | Controller, | ||
IN EFI_DEVICE_PATH_PROTOCOL * | RemainingDevicePath | ||
) |
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.
[in] | This | A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance. |
[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. |
[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. |
EFI_SUCCESS | The device was started. |
EFI_DEVICE_ERROR | The device could not be started due to a device error.Currently not implemented. |
EFI_OUT_OF_RESOURCES | The request could not be completed due to a lack of resources. |
Others | The driver failed to start the device. |
EFI_STATUS EFIAPI I2cHostDriverStop | ( | IN EFI_DRIVER_BINDING_PROTOCOL * | This, |
IN EFI_HANDLE | Controller, | ||
IN UINTN | NumberOfChildren, | ||
IN EFI_HANDLE * | ChildHandleBuffer | ||
) |
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.
[in] | This | A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance. |
[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. |
[in] | NumberOfChildren | The number of child device handles in ChildHandleBuffer. |
[in] | ChildHandleBuffer | An array of child handles to be freed. May be NULL if NumberOfChildren is 0. |
EFI_SUCCESS | The device was stopped. |
EFI_DEVICE_ERROR | The device could not be stopped due to a device error. |
EFI_STATUS EFIAPI I2cHostDriverSupported | ( | IN EFI_DRIVER_BINDING_PROTOCOL * | This, |
IN EFI_HANDLE | Controller, | ||
IN EFI_DEVICE_PATH_PROTOCOL * | RemainingDevicePath | ||
) |
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.
[in] | This | A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance. |
[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. |
[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. |
EFI_SUCCESS | The device specified by ControllerHandle and RemainingDevicePath is supported by the driver specified by This. |
EFI_ALREADY_STARTED | The device specified by ControllerHandle and RemainingDevicePath is already being managed by the driver specified by This. |
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. |
EFI_UNSUPPORTED | The device specified by ControllerHandle and RemainingDevicePath is not supported by the driver specified by This. |
Handle the I2C bus configuration available event
This routine is called at TPL_I2C_SYNC.
[in] | Event | Address of an EFI_EVENT handle |
[in] | Context | Address of an I2C_HOST_CONTEXT structure |
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 | ||
) |
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 I2C Specification 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.
[in] | This | Address of an EFI_I2C_HOST_PROTOCOL instance. |
[in] | I2cBusConfiguration | I2C bus configuration to access the I2C device. |
[in] | SlaveAddress | Address of the device on the I2C bus. |
[in] | Event | Event to set for asynchronous operations, NULL for synchronous operations |
[in] | RequestPacket | Address of an EFI_I2C_REQUEST_PACKET structure describing the I2C operation |
[out] | I2cStatus | Optional buffer to receive the I2C operation completion status |
EFI_SUCCESS | The operation completed successfully. |
EFI_ABORTED | The request did not complete because the driver was shutdown. |
EFI_BAD_BUFFER_SIZE | The WriteBytes or ReadBytes buffer size is too large. |
EFI_DEVICE_ERROR | There was an I2C error (NACK) during the operation. This could indicate the slave device is not present. |
EFI_INVALID_PARAMETER | RequestPacket is NULL |
EFI_INVALID_PARAMETER | TPL is too high |
EFI_NO_MAPPING | Invalid I2cBusConfiguration value |
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. |
EFI_NOT_FOUND | I2C slave address exceeds maximum address |
EFI_NOT_READY | I2C bus is busy or operation pending, wait for the event and then read status pointed to by the request packet. |
EFI_OUT_OF_RESOURCES | Insufficient memory for I2C operation |
EFI_TIMEOUT | The transaction did not complete within an internally specified timeout period. |
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 I2C Specification 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.
[in] | This | Address of an EFI_I2C_HOST_PROTOCOL instance. |
[in] | I2cBusConfiguration | I2C bus configuration to access the I2C device. |
[in] | SlaveAddress | Address of the device on the I2C bus. |
[in] | Event | Event to set for asynchronous operations, NULL for synchronous operations |
[in] | RequestPacket | Address of an EFI_I2C_REQUEST_PACKET structure describing the I2C operation |
[out] | I2cStatus | Optional buffer to receive the I2C operation completion status |
EFI_SUCCESS | The operation completed successfully. |
EFI_BAD_BUFFER_SIZE | The WriteBytes or ReadBytes buffer size is too large. |
EFI_DEVICE_ERROR | There was an I2C error (NACK) during the operation. This could indicate the slave device is not present. |
EFI_INVALID_PARAMETER | RequestPacket is NULL |
EFI_INVALID_PARAMETER | TPL is too high |
EFI_NO_MAPPING | Invalid I2cBusConfiguration value |
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. |
EFI_NOT_FOUND | I2C slave address exceeds maximum address |
EFI_NOT_READY | I2C bus is busy or operation pending, wait for the event and then read status pointed to by the request packet. |
EFI_OUT_OF_RESOURCES | Insufficient memory for I2C operation |
EFI_TIMEOUT | The transaction did not complete within an internally specified timeout period. |
EFI_STATUS I2cHostRequestComplete | ( | I2C_HOST_CONTEXT * | I2cHostContext, |
EFI_STATUS | Status | ||
) |
Complete the current request
[in] | I2cHost | Address of an I2C_HOST_CONTEXT structure. |
[in] | Status | Status of the I2C operation. |
Complete the current request
This routine is called at TPL_I2C_SYNC.
[in] | I2cHostContext | Address of an I2C_HOST_CONTEXT structure. |
[in] | Status | Status of the I2C operation. |
Handle the bus available event
This routine is called at TPL_I2C_SYNC.
[in] | Event | Address of an EFI_EVENT handle |
[in] | Context | Address of an I2C_HOST_CONTEXT structure |
EFI_STATUS I2cHostRequestEnable | ( | I2C_HOST_CONTEXT * | I2cHostContext | ) |
Enable access to the I2C bus configuration
[in] | I2cHostContext | Address of an I2C_HOST_CONTEXT structure |
EFI_SUCCESS | The operation completed successfully. |
EFI_ABORTED | The request did not complete because the driver was shutdown. |
EFI_BAD_BUFFER_SIZE | The WriteBytes or ReadBytes buffer size is too large. |
EFI_DEVICE_ERROR | There was an I2C error (NACK) during the operation. This could indicate the slave device is not present. |
EFI_INVALID_PARAMETER | RequestPacket is NULL |
EFI_NO_MAPPING | Invalid I2cBusConfiguration value |
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. |
EFI_NOT_FOUND | I2C slave address exceeds maximum address |
EFI_NOT_READY | I2C bus is busy or operation pending, wait for the event and then read status. |
EFI_OUT_OF_RESOURCES | Insufficient memory for I2C operation |
EFI_TIMEOUT | The transaction did not complete within an internally specified timeout period. |
EFI_STATUS EFIAPI I2cHostUnload | ( | IN EFI_HANDLE | ImageHandle | ) |
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.
[in] | ImageHandle | The drivers' driver image. |
EFI_SUCCESS | The image is unloaded. |
Others | Failed to unload the image. |
EFI_STATUS EFIAPI InitializeI2cBus | ( | IN EFI_HANDLE | ImageHandle, |
IN EFI_SYSTEM_TABLE * | SystemTable | ||
) |
The user entry point for the I2C bus module. The user code starts with this function.
[in] | ImageHandle | The firmware allocated handle for the EFI image. |
[in] | SystemTable | A pointer to the EFI System Table. |
EFI_SUCCESS | The entry point is executed successfully. |
other | Some error occurs when executing this entry point. |
EFI_STATUS EFIAPI InitializeI2cHost | ( | IN EFI_HANDLE | ImageHandle, |
IN EFI_SYSTEM_TABLE * | SystemTable | ||
) |
The user Entry Point for I2C host module. The user code starts with this function.
[in] | ImageHandle | The firmware allocated handle for the EFI image. |
[in] | SystemTable | A pointer to the EFI System Table. |
EFI_SUCCESS | The entry point is executed successfully. |
other | Some error occurs when executing this entry point. |
EFI_STATUS RegisterI2cDevice | ( | IN I2C_BUS_CONTEXT * | I2cBusContext, |
IN EFI_HANDLE | Controller, | ||
IN EFI_DEVICE_PATH_PROTOCOL * | RemainingDevicePath | ||
) |
Start the I2C driver
This routine allocates the necessary resources for the driver.
This routine is called by I2cBusDriverStart to complete the driver initialization.
[in] | I2cBus | Address of an I2C_BUS_CONTEXT structure |
[in] | Controller | Handle to the controller |
[in] | RemainingDevicePath | A pointer to the remaining portion of a device path. |
EFI_SUCCESS | Driver API properly initialized |
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.
[in] | I2cBusContext | Address of an I2C_BUS_CONTEXT structure |
[in] | Controller | Handle to the controller |
[in] | RemainingDevicePath | A pointer to the remaining portion of a device path. |
EFI_SUCCESS | The bus is successfully configured |
VOID ReleaseI2cDeviceContext | ( | IN I2C_DEVICE_CONTEXT * | I2cDeviceContext | ) |
EFI_STATUS UnRegisterI2cDevice | ( | IN EFI_DRIVER_BINDING_PROTOCOL * | This, |
IN EFI_HANDLE | Controller, | ||
IN EFI_HANDLE | Handle | ||
) |
Unregister an I2C device.
This function removes the protocols installed on the controller handle and frees the resources allocated for the I2C device.
This | The pointer to EFI_DRIVER_BINDING_PROTOCOL instance. |
Controller | The controller handle of the I2C device. |
Handle | The child handle. |
EFI_SUCCESS | The I2C device is successfully unregistered. |
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