#include "I2cDxe.h"

Functions
EFI_STATUS EFIAPI	I2cHostComponentNameGetDriverName (IN EFI_COMPONENT_NAME2_PROTOCOL This, IN CHAR8 Language, OUT CHAR16 **DriverName)

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)

EFI_STATUS EFIAPI	I2cHostDriverSupported (IN EFI_DRIVER_BINDING_PROTOCOL This, IN EFI_HANDLE Controller, IN EFI_DEVICE_PATH_PROTOCOL RemainingDevicePath)

EFI_STATUS EFIAPI	I2cHostDriverStart (IN EFI_DRIVER_BINDING_PROTOCOL This, IN EFI_HANDLE Controller, IN EFI_DEVICE_PATH_PROTOCOL RemainingDevicePath)

EFI_STATUS EFIAPI	I2cHostDriverStop (IN EFI_DRIVER_BINDING_PROTOCOL This, IN EFI_HANDLE Controller, IN UINTN NumberOfChildren, IN EFI_HANDLE ChildHandleBuffer)

VOID EFIAPI	I2cHostI2cBusConfigurationAvailable (IN EFI_EVENT Event, IN VOID *Context)

EFI_STATUS	I2cHostRequestComplete (I2C_HOST_CONTEXT *I2cHostContext, EFI_STATUS Status)

VOID EFIAPI	I2cHostRequestCompleteEvent (IN EFI_EVENT Event, IN VOID *Context)

EFI_STATUS	I2cHostRequestEnable (I2C_HOST_CONTEXT *I2cHostContext)

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 EFIAPI	InitializeI2cHost (IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable)

EFI_STATUS EFIAPI	I2cHostUnload (IN EFI_HANDLE ImageHandle)

Variables
EFI_DRIVER_BINDING_PROTOCOL	gI2cHostDriverBinding

GLOBAL_REMOVE_IF_UNREFERENCED EFI_UNICODE_STRING_TABLE	mI2cHostDriverNameTable []

GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME_PROTOCOL	gI2cHostComponentName

GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME2_PROTOCOL	gI2cHostComponentName2

Detailed Description

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) 2014, Hewlett-Packard Development Company, L.P.
Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file I2cHost.c.

Function Documentation

◆ I2cHostComponentNameGetControllerName()

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.

Parameters

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.

Return values

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.

Definition at line 174 of file I2cHost.c.

◆ I2cHostComponentNameGetDriverName()

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.

Parameters

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.

Return values

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.

Definition at line 89 of file I2cHost.c.

◆ I2cHostDriverStart()

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.

ControllerHandle must be a valid EFI_HANDLE.
If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned EFI_DEVICE_PATH_PROTOCOL.
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.

Parameters

[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.

Return values

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.

Definition at line 319 of file I2cHost.c.

◆ I2cHostDriverStop()

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.

ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this same driver's Start() function.
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.

Parameters

[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.

Return values

EFI_SUCCESS	The device was stopped.
EFI_DEVICE_ERROR	The device could not be stopped due to a device error.

Definition at line 503 of file I2cHost.c.

◆ I2cHostDriverSupported()

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.

Parameters

[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.

Return values

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.

Definition at line 229 of file I2cHost.c.

◆ I2cHostI2cBusConfigurationAvailable()

VOID EFIAPI I2cHostI2cBusConfigurationAvailable	(	IN EFI_EVENT	Event,
		IN VOID *	Context
	)

Handle the I2C bus configuration available event

This routine is called at TPL_I2C_SYNC.

Parameters

[in]	Event	Address of an EFI_EVENT handle
[in]	Context	Address of an I2C_HOST_CONTEXT structure

Definition at line 604 of file I2cHost.c.

◆ I2cHostQueueRequest()

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.

Parameters

[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

Return values

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.

Definition at line 915 of file I2cHost.c.

◆ I2cHostRequestComplete()

EFI_STATUS I2cHostRequestComplete	(	I2C_HOST_CONTEXT *	I2cHostContext,
		EFI_STATUS	Status
	)

Complete the current request

This routine is called at TPL_I2C_SYNC.

Parameters

[in]	I2cHostContext	Address of an I2C_HOST_CONTEXT structure.
[in]	Status	Status of the I2C operation.

Returns: This routine returns the input status value.

Definition at line 688 of file I2cHost.c.

◆ I2cHostRequestCompleteEvent()

VOID EFIAPI I2cHostRequestCompleteEvent	(	IN EFI_EVENT	Event,
		IN VOID *	Context
	)

Handle the bus available event

This routine is called at TPL_I2C_SYNC.

Parameters

[in]	Event	Address of an EFI_EVENT handle
[in]	Context	Address of an I2C_HOST_CONTEXT structure

Definition at line 746 of file I2cHost.c.

◆ I2cHostRequestEnable()

EFI_STATUS I2cHostRequestEnable ( I2C_HOST_CONTEXT * I2cHostContext )

Enable access to the I2C bus configuration

Parameters

[in] I2cHostContext Address of an I2C_HOST_CONTEXT structure

Return values

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.

Definition at line 786 of file I2cHost.c.

◆ I2cHostUnload()

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.

Parameters

[in] ImageHandle The drivers' driver image.

Return values

EFI_SUCCESS	The image is unloaded.
Others	Failed to unload the image.

Definition at line 1125 of file I2cHost.c.

◆ InitializeI2cHost()

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.

Parameters

[in]	ImageHandle	The firmware allocated handle for the EFI image.
[in]	SystemTable	A pointer to the EFI System Table.

Return values

EFI_SUCCESS	The entry point is executed successfully.
other	Some error occurs when executing this entry point.

Definition at line 1089 of file I2cHost.c.

Variable Documentation

◆ gI2cHostComponentName

GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME_PROTOCOL gI2cHostComponentName

Initial value:

= {
  (EFI_COMPONENT_NAME_GET_DRIVER_NAME)I2cHostComponentNameGetDriverName,
  (EFI_COMPONENT_NAME_GET_CONTROLLER_NAME)I2cHostComponentNameGetControllerName,
  "eng"
}

Definition at line 33 of file I2cHost.c.

◆ gI2cHostComponentName2

GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME2_PROTOCOL gI2cHostComponentName2

Initial value:

= {
  I2cHostComponentNameGetDriverName,
  I2cHostComponentNameGetControllerName,
  "en"
}

Definition at line 42 of file I2cHost.c.

◆ gI2cHostDriverBinding

EFI_DRIVER_BINDING_PROTOCOL gI2cHostDriverBinding

Initial value:

= {
  I2cHostDriverSupported,
  I2cHostDriverStart,
  I2cHostDriverStop,
  0x10,
  NULL,
  NULL
}

Definition at line 13 of file I2cHost.c.

◆ mI2cHostDriverNameTable

GLOBAL_REMOVE_IF_UNREFERENCED EFI_UNICODE_STRING_TABLE mI2cHostDriverNameTable[]

Initial value:

= {
  { "eng;en", L"I2c Host Driver" },
  { NULL,     NULL               }
}

Definition at line 25 of file I2cHost.c.

Functions

Variables

Detailed Description

Function Documentation

◆ I2cHostComponentNameGetControllerName()

◆ I2cHostComponentNameGetDriverName()

◆ I2cHostDriverStart()

◆ I2cHostDriverStop()

◆ I2cHostDriverSupported()

◆ I2cHostI2cBusConfigurationAvailable()

◆ I2cHostQueueRequest()

◆ I2cHostRequestComplete()

◆ I2cHostRequestCompleteEvent()

◆ I2cHostRequestEnable()

◆ I2cHostUnload()

◆ InitializeI2cHost()

Variable Documentation

◆ gI2cHostComponentName

◆ gI2cHostComponentName2

◆ gI2cHostDriverBinding

◆ mI2cHostDriverNameTable