EdkCompatibilityPkg/Foundation/Core/Dxe/ArchProtocol/Timer/Timer.h

   1 /*++
   2
   3 Copyright (c) 2004, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   Timer.h
  15
  16 Abstract:
  17
  18   Timer Architectural Protocol as defined in the DXE CIS
  19
  20   This code is used to provide the timer tick for the DXE core.
  21
  22 --*/
  23
  24 #ifndef _ARCH_PROTOCOL_TIMER_H_
  25 #define _ARCH_PROTOCOL_TIMER_H_
  26
  27 //
  28 // Global ID for the Timer Architectural Protocol
  29 //
  30 #define EFI_TIMER_ARCH_PROTOCOL_GUID \
  31   { 0x26baccb3, 0x6f42, 0x11d4, 0xbc, 0xe7, 0x0, 0x80, 0xc7, 0x3c, 0x88, 0x81 }
  32
  33 //
  34 // Declare forward reference for the Timer Architectural Protocol
  35 //
  36 EFI_FORWARD_DECLARATION (EFI_TIMER_ARCH_PROTOCOL);
  37
  38 typedef
  39 VOID
  40 (EFIAPI *EFI_TIMER_NOTIFY) (
  41   IN UINT64  Time
  42   );
  43 /*++
  44
  45 Routine Description:
  46
  47   This function of this type is called when a timer interrupt fires.  This
  48   function executes at TPL_HIGH_LEVEL.  The DXE Core will register a funtion
  49   of tyis type to be called for the timer interrupt, so it can know how much
  50   time has passed.  This information is used to signal timer based events.
  51
  52 Arguments:
  53
  54   Time - Time since the last timer interrupt in 100 ns units.  This will
  55          typically be TimerPeriod, but if a timer interrupt is missed, and the
  56          EFI_TIMER_ARCH_PROTOCOL driver can detect missed interrupts, then Time
  57          will contain the actual amount of time since the last interrupt.
  58
  59 Returns:
  60
  61   None.
  62
  63 --*/
  64
  65 typedef
  66 EFI_STATUS
  67 (EFIAPI *EFI_TIMER_REGISTER_HANDLER) (
  68   IN EFI_TIMER_ARCH_PROTOCOL    *This,
  69   IN EFI_TIMER_NOTIFY           NotifyFunction
  70 );
  71 /*++
  72
  73 Routine Description:
  74
  75   This function registers the handler NotifyFunction so it is called every time
  76   the timer interrupt fires.  It also passes the amount of time since the last
  77   handler call to the NotifyFunction.  If NotifyFunction is NULL, then the
  78   handler is unregistered.  If the handler is registered, then EFI_SUCCESS is
  79   returned.  If the CPU does not support registering a timer interrupt handler,
  80   then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler
  81   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
  82   If an attempt is made to unregister a handler when a handler is not registered,
  83   then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to
  84   register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
  85   is returned.
  86
  87 Arguments:
  88
  89   This           - The EFI_TIMER_ARCH_PROTOCOL instance.
  90
  91   NotifyFunction - The function to call when a timer interrupt fires.  This
  92                    function executes at TPL_HIGH_LEVEL.  The DXE Core will
  93                    register a handler for the timer interrupt, so it can know
  94                    how much time has passed.  This information is used to
  95                    signal timer based events.  NULL will unregister the handler.
  96
  97 Returns:
  98
  99   EFI_SUCCESS           - The timer handler was registered.
 100
 101   EFI_UNSUPPORTED       - The platform does not support timer interrupts.
 102
 103   EFI_ALREADY_STARTED   - NotifyFunction is not NULL, and a handler is already
 104                           registered.
 105
 106   EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not
 107                           previously registered.
 108
 109   EFI_DEVICE_ERROR      - The timer handler could not be registered.
 110
 111 --*/
 112
 113 typedef
 114 EFI_STATUS
 115 (EFIAPI *EFI_TIMER_SET_TIMER_PERIOD) (
 116   IN EFI_TIMER_ARCH_PROTOCOL    *This,
 117   IN UINT64                     TimerPeriod
 118   );
 119 /*++
 120
 121 Routine Description:
 122
 123   This function adjusts the period of timer interrupts to the value specified
 124   by TimerPeriod.  If the timer period is updated, then the selected timer
 125   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
 126   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
 127   If an error occurs while attempting to update the timer period, then the
 128   timer hardware will be put back in its state prior to this call, and
 129   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 130   is disabled.  This is not the same as disabling the CPU's interrupts.
 131   Instead, it must either turn off the timer hardware, or it must adjust the
 132   interrupt controller so that a CPU interrupt is not generated when the timer
 133   interrupt fires.
 134
 135 Arguments:
 136
 137   This        - The EFI_TIMER_ARCH_PROTOCOL instance.
 138
 139   TimerPeriod - The rate to program the timer interrupt in 100 nS units.  If
 140                 the timer hardware is not programmable, then EFI_UNSUPPORTED is
 141                 returned.  If the timer is programmable, then the timer period
 142                 will be rounded up to the nearest timer period that is supported
 143                 by the timer hardware.  If TimerPeriod is set to 0, then the
 144                 timer interrupts will be disabled.
 145
 146 Returns:
 147
 148   EFI_SUCCESS      - The timer period was changed.
 149
 150   EFI_UNSUPPORTED  - The platform cannot change the period of the timer interrupt.
 151
 152   EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.
 153
 154 --*/
 155
 156 typedef
 157 EFI_STATUS
 158 (EFIAPI *EFI_TIMER_GET_TIMER_PERIOD) (
 159   IN EFI_TIMER_ARCH_PROTOCOL    *This,
 160   OUT UINT64                     *TimerPeriod
 161   );
 162 /*++
 163
 164 Routine Description:
 165
 166   This function retrieves the period of timer interrupts in 100 ns units,
 167   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 168   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 169   returned, then the timer is currently disabled.
 170
 171 Arguments:
 172
 173   This        - The EFI_TIMER_ARCH_PROTOCOL instance.
 174
 175   TimerPeriod - A pointer to the timer period to retrieve in 100 ns units.  If
 176                 0 is returned, then the timer is currently disabled.
 177
 178 Returns:
 179
 180   EFI_SUCCESS           - The timer period was returned in TimerPeriod.
 181
 182   EFI_INVALID_PARAMETER - TimerPeriod is NULL.
 183
 184 --*/
 185
 186 typedef
 187 EFI_STATUS
 188 (EFIAPI *EFI_TIMER_GENERATE_SOFT_INTERRUPT) (
 189   IN EFI_TIMER_ARCH_PROTOCOL    *This
 190   );
 191 /*++
 192
 193 Routine Description:
 194
 195   This function generates a soft timer interrupt. If the platform does not support soft
 196   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 197   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 198   service, then a soft timer interrupt will be generated. If the timer interrupt is
 199   enabled when this service is called, then the registered handler will be invoked. The
 200   registered handler should not be able to distinguish a hardware-generated timer
 201   interrupt from a software-generated timer interrupt.
 202
 203 Arguments:
 204
 205   This  -  The EFI_TIMER_ARCH_PROTOCOL instance.
 206
 207 Returns:
 208
 209   EFI_SUCCESS       - The soft timer interrupt was generated.
 210
 211   EFI_UNSUPPORTEDT  - The platform does not support the generation of soft timer interrupts.
 212
 213 --*/
 214
 215 //
 216 // Interface stucture for the Timer Architectural Protocol
 217 //
 218 typedef struct _EFI_TIMER_ARCH_PROTOCOL {
 219   EFI_TIMER_REGISTER_HANDLER          RegisterHandler;
 220   EFI_TIMER_SET_TIMER_PERIOD          SetTimerPeriod;
 221   EFI_TIMER_GET_TIMER_PERIOD          GetTimerPeriod;
 222   EFI_TIMER_GENERATE_SOFT_INTERRUPT   GenerateSoftInterrupt;
 223 } EFI_TIMER_ARCH_PROTOCOL;
 224
 225 /*++
 226
 227   Protocol Description:
 228     This protocol provides the services to initialize a periodic timer
 229     interrupt, and to register a handler that is called each time the timer
 230     interrupt fires.  It may also provide a service to adjust the rate of the
 231     periodic timer interrupt.  When a timer interrupt occurs, the handler is
 232     passed the amount of time that has passed since the previous timer
 233     interrupt.
 234
 235   Parameters:
 236
 237     RegisterHandler - Registers a handler that will be called each time the
 238                       timer interrupt fires.  TimerPeriod defines the minimum
 239                       time between timer interrupts, so TimerPeriod will also
 240                       be the minimum time between calls to the registered
 241                       handler.
 242
 243     SetTimerPeriod  - Sets the period of the timer interrupt in 100 nS units.
 244                       This function is optional, and may return EFI_UNSUPPORTED.
 245                       If this function is supported, then the timer period will
 246                       be rounded up to the nearest supported timer period.
 247
 248     GetTimerPeriod  - Retrieves the period of the timer interrupt in 100 nS units.
 249
 250     GenerateSoftInterrupt -
 251                       Generates a soft timer interrupt that simulates the firing of
 252                       the timer interrupt. This service can be used to invoke the
 253                       registered handler if the timer interrupt has been masked for
 254                       a period of time.
 255
 256 --*/
 257
 258 extern EFI_GUID gEfiTimerArchProtocolGuid;
 259
 260 #endif