mirror of https://github.com/acidanthera/audk.git
170 lines
7.2 KiB
C
170 lines
7.2 KiB
C
/*++
|
|
|
|
Copyright (c) 2004 - 2014, 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 that 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.
|
|
|
|
|
|
|
|
|
|
**/
|
|
|
|
#ifndef __I2C_BUS_H__
|
|
#define __I2C_BUS_H__
|
|
|
|
#include <Protocol/I2cHostMcg.h>
|
|
|
|
//
|
|
// I2C bus protocol
|
|
//
|
|
typedef struct _EFI_I2C_BUS_PROTOCOL EFI_I2C_BUS_PROTOCOL;
|
|
|
|
|
|
/**
|
|
Perform an I2C operation on the device
|
|
|
|
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 third party I2C
|
|
drivers. 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 routine queues an operation to the I2C controller for execution
|
|
on the I2C bus.
|
|
|
|
As an upper layer driver writer, the following need to be provided
|
|
to the platform vendor:
|
|
|
|
1. ACPI CID value or string - this is used to connect the upper layer
|
|
driver to the device.
|
|
2. Slave address array guidance when the I2C device uses more than one
|
|
slave address. This is used to access the blocks of hardware within
|
|
the I2C device.
|
|
|
|
@param[in] This Address of an EFI_I2C_BUS_PROTOCOL
|
|
structure
|
|
@param[in] SlaveAddressIndex Index into an array of slave addresses for
|
|
the I2C device. The values in the array are
|
|
specified by the board designer, with the
|
|
I2C device driver writer providing the slave
|
|
address order.
|
|
|
|
For devices that have a single slave address,
|
|
this value must be zero. If the I2C device
|
|
uses more than one slave address then the third
|
|
party (upper level) I2C driver writer needs to
|
|
specify the order of entries in the slave address
|
|
array.
|
|
|
|
\ref ThirdPartyI2cDrivers "Third Party I2C Drivers"
|
|
section in I2cMaster.h.
|
|
@param[in] Event Event to 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_ACCESS_DENIED Invalid SlaveAddressIndex value
|
|
@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_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.
|
|
|
|
**/
|
|
typedef
|
|
EFI_STATUS
|
|
(EFIAPI *EFI_I2C_BUS_START_REQUEST) (
|
|
IN CONST EFI_I2C_BUS_PROTOCOL *This,
|
|
IN UINTN SlaveAddressIndex,
|
|
IN EFI_EVENT Event OPTIONAL,
|
|
IN CONST EFI_I2C_REQUEST_PACKET *RequestPacket,
|
|
OUT EFI_STATUS *I2cStatus OPTIONAL
|
|
);
|
|
|
|
//
|
|
// The I2C bus protocol enables access to a specific device on the I2C bus.
|
|
//
|
|
// Each I2C device is described as an ACPI node (HID, UID and CID) within the
|
|
// platform layer. The I2C bus protocol enumerates the I2C devices in the
|
|
// platform and creates a unique handle and device path for each I2C device.
|
|
//
|
|
// I2C slave addressing is abstracted to validate addresses and limit operation
|
|
// to the specified I2C device. The third party providing the I2C device support
|
|
// provides an ordered list of slave addresses for the I2C device to the team
|
|
// building the platform layer. The platform team must preserve the order of the
|
|
// supplied list. SlaveAddressCount is the number of entries in this list or
|
|
// array within the platform layer. The third party device support references
|
|
// a slave address using an index into the list or array in the range of zero
|
|
// to SlaveAddressCount - 1.
|
|
//
|
|
struct _EFI_I2C_BUS_PROTOCOL {
|
|
//
|
|
// Start an I2C operation on the bus
|
|
//
|
|
EFI_I2C_BUS_START_REQUEST StartRequest;
|
|
|
|
//
|
|
// The maximum number of slave addresses for the I2C device. The caller may
|
|
// validate this value as a check on the platform layer's configuration. Slave
|
|
// address selection uses an index value in the range of zero to SlaveAddressCount - 1.
|
|
//
|
|
UINTN SlaveAddressCount;
|
|
|
|
//
|
|
// Hardware revision - Matches the ACPI _HRV value
|
|
//
|
|
// The HardwareRevision value allows a single driver to support multiple hardware
|
|
// revisions and implement the necessary workarounds for limitations within the
|
|
// hardware.
|
|
//
|
|
UINT32 HardwareRevision;
|
|
|
|
//
|
|
// The maximum number of bytes the I2C host controller
|
|
// is able to receive from the I2C bus.
|
|
//
|
|
UINT32 MaximumReceiveBytes;
|
|
|
|
//
|
|
// The maximum number of bytes the I2C host controller
|
|
// is able to send on the I2C bus.
|
|
//
|
|
UINT32 MaximumTransmitBytes;
|
|
|
|
//
|
|
// The maximum number of bytes in the I2C bus transaction.
|
|
//
|
|
UINT32 MaximumTotalBytes;
|
|
};
|
|
|
|
//
|
|
// GUID for the I2C bus protocol
|
|
//
|
|
extern EFI_GUID gEfiI2cBusProtocolGuid;
|
|
|
|
#endif // __I2C_BUS_H__
|