mirror of https://github.com/acidanthera/audk.git
81 lines
3.2 KiB
C
81 lines
3.2 KiB
C
/** @file
|
|
Metronome Architectural Protocol as defined in PI SPEC VOLUME 2 DXE
|
|
|
|
This code abstracts the DXE core to provide delay services.
|
|
|
|
Copyright (c) 2006 - 2018, 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.
|
|
|
|
**/
|
|
|
|
#ifndef __ARCH_PROTOCOL_METRONOME_H__
|
|
#define __ARCH_PROTOCOL_METRONOME_H__
|
|
|
|
///
|
|
/// Global ID for the Metronome Architectural Protocol
|
|
///
|
|
#define EFI_METRONOME_ARCH_PROTOCOL_GUID \
|
|
{ 0x26baccb2, 0x6f42, 0x11d4, {0xbc, 0xe7, 0x0, 0x80, 0xc7, 0x3c, 0x88, 0x81 } }
|
|
|
|
///
|
|
/// Declare forward reference for the Metronome Architectural Protocol
|
|
///
|
|
typedef struct _EFI_METRONOME_ARCH_PROTOCOL EFI_METRONOME_ARCH_PROTOCOL;
|
|
|
|
/**
|
|
The WaitForTick() function waits for the number of ticks specified by
|
|
TickNumber from a known time source in the platform. If TickNumber of
|
|
ticks are detected, then EFI_SUCCESS is returned. The actual time passed
|
|
between entry of this function and the first tick is between 0 and
|
|
TickPeriod 100 nS units. If you want to guarantee that at least TickPeriod
|
|
time has elapsed, wait for two ticks. This function waits for a hardware
|
|
event to determine when a tick occurs. It is possible for interrupt
|
|
processing, or exception processing to interrupt the execution of the
|
|
WaitForTick() function. Depending on the hardware source for the ticks, it
|
|
is possible for a tick to be missed. This function cannot guarantee that
|
|
ticks will not be missed. If a timeout occurs waiting for the specified
|
|
number of ticks, then EFI_TIMEOUT is returned.
|
|
|
|
@param This The EFI_METRONOME_ARCH_PROTOCOL instance.
|
|
@param TickNumber Number of ticks to wait.
|
|
|
|
@retval EFI_SUCCESS The wait for the number of ticks specified by TickNumber
|
|
succeeded.
|
|
@retval EFI_TIMEOUT A timeout occurred waiting for the specified number of ticks.
|
|
|
|
**/
|
|
typedef
|
|
EFI_STATUS
|
|
(EFIAPI *EFI_METRONOME_WAIT_FOR_TICK)(
|
|
IN EFI_METRONOME_ARCH_PROTOCOL *This,
|
|
IN UINT32 TickNumber
|
|
);
|
|
|
|
///
|
|
/// This protocol provides access to a known time source in the platform to the
|
|
/// core. The core uses this known time source to produce core services that
|
|
/// require calibrated delays.
|
|
///
|
|
struct _EFI_METRONOME_ARCH_PROTOCOL {
|
|
EFI_METRONOME_WAIT_FOR_TICK WaitForTick;
|
|
|
|
///
|
|
/// The period of platform's known time source in 100 nS units.
|
|
/// This value on any platform must be at least 10 uS, and must not
|
|
/// exceed 200 uS. The value in this field is a constant that must
|
|
/// not be modified after the Metronome architectural protocol is
|
|
/// installed. All consumers must treat this as a read-only field.
|
|
///
|
|
UINT32 TickPeriod;
|
|
};
|
|
|
|
extern EFI_GUID gEfiMetronomeArchProtocolGuid;
|
|
|
|
#endif
|