PcAtChipsetPkg/8254TimerDxe/Timer.h

   1 /** @file
   2   Private data structures
   3
   4 Copyright (c) 2005 - 2010, Intel Corporation. All rights reserved. <BR>
   5 This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12 **/
  13
  14 #ifndef _TIMER_H_
  15 #define _TIMER_H_
  16
  17 #include <PiDxe.h>
  18
  19 #include <Protocol/Cpu.h>
  20 #include <Protocol/Legacy8259.h>
  21 #include <Protocol/Timer.h>
  22
  23 #include <Library/UefiBootServicesTableLib.h>
  24 #include <Library/BaseLib.h>
  25 #include <Library/DebugLib.h>
  26 #include <Library/IoLib.h>
  27
  28 //
  29 // The PCAT 8253/8254 has an input clock at 1.193182 MHz and Timer 0 is
  30 // initialized as a 16 bit free running counter that generates an interrupt(IRQ0)
  31 // each time the counter rolls over.
  32 //
  33 //   65536 counts
  34 // ---------------- * 1,000,000 uS/S = 54925.4 uS = 549254 * 100 ns
  35 //   1,193,182 Hz
  36 //
  37 // The default timer tick duration is set to 10 ms = 100000 100 ns units
  38 //
  39 #define DEFAULT_TIMER_TICK_DURATION 100000
  40 #define TIMER_CONTROL_PORT          0x43
  41 #define TIMER0_COUNT_PORT           0x40
  42
  43 //
  44 // Function Prototypes
  45 //
  46 /**
  47   Initialize the Timer Architectural Protocol driver
  48
  49   @param ImageHandle     ImageHandle of the loaded driver
  50   @param SystemTable     Pointer to the System Table
  51
  52   @retval EFI_SUCCESS            Timer Architectural Protocol created
  53   @retval EFI_OUT_OF_RESOURCES   Not enough resources available to initialize driver.
  54   @retval EFI_DEVICE_ERROR       A device error occured attempting to initialize the driver.
  55
  56 **/
  57 EFI_STATUS
  58 EFIAPI
  59 TimerDriverInitialize (
  60   IN EFI_HANDLE        ImageHandle,
  61   IN EFI_SYSTEM_TABLE  *SystemTable
  62   )
  63 ;
  64
  65 /**
  66
  67   This function adjusts the period of timer interrupts to the value specified
  68   by TimerPeriod.  If the timer period is updated, then the selected timer
  69   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
  70   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
  71   If an error occurs while attempting to update the timer period, then the
  72   timer hardware will be put back in its state prior to this call, and
  73   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
  74   is disabled.  This is not the same as disabling the CPU's interrupts.
  75   Instead, it must either turn off the timer hardware, or it must adjust the
  76   interrupt controller so that a CPU interrupt is not generated when the timer
  77   interrupt fires.
  78
  79
  80   @param This            The EFI_TIMER_ARCH_PROTOCOL instance.
  81   @param TimerPeriod     The rate to program the timer interrupt in 100 nS units.  If
  82                          the timer hardware is not programmable, then EFI_UNSUPPORTED is
  83                          returned.  If the timer is programmable, then the timer period
  84                          will be rounded up to the nearest timer period that is supported
  85                          by the timer hardware.  If TimerPeriod is set to 0, then the
  86                          timer interrupts will be disabled.
  87
  88   @retval        EFI_SUCCESS       The timer period was changed.
  89   @retval        EFI_UNSUPPORTED   The platform cannot change the period of the timer interrupt.
  90   @retval        EFI_DEVICE_ERROR  The timer period could not be changed due to a device error.
  91
  92 **/
  93 EFI_STATUS
  94 EFIAPI
  95 TimerDriverRegisterHandler (
  96   IN EFI_TIMER_ARCH_PROTOCOL  *This,
  97   IN EFI_TIMER_NOTIFY         NotifyFunction
  98   )
  99 ;
 100
 101 /**
 102
 103   This function adjusts the period of timer interrupts to the value specified
 104   by TimerPeriod.  If the timer period is updated, then the selected timer
 105   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
 106   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
 107   If an error occurs while attempting to update the timer period, then the
 108   timer hardware will be put back in its state prior to this call, and
 109   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 110   is disabled.  This is not the same as disabling the CPU's interrupts.
 111   Instead, it must either turn off the timer hardware, or it must adjust the
 112   interrupt controller so that a CPU interrupt is not generated when the timer
 113   interrupt fires.
 114
 115
 116   @param This            The EFI_TIMER_ARCH_PROTOCOL instance.
 117   @param TimerPeriod     The rate to program the timer interrupt in 100 nS units.  If
 118                          the timer hardware is not programmable, then EFI_UNSUPPORTED is
 119                          returned.  If the timer is programmable, then the timer period
 120                          will be rounded up to the nearest timer period that is supported
 121                          by the timer hardware.  If TimerPeriod is set to 0, then the
 122                          timer interrupts will be disabled.
 123
 124   @retval        EFI_SUCCESS       The timer period was changed.
 125   @retval        EFI_UNSUPPORTED   The platform cannot change the period of the timer interrupt.
 126   @retval        EFI_DEVICE_ERROR  The timer period could not be changed due to a device error.
 127
 128 **/
 129 EFI_STATUS
 130 EFIAPI
 131 TimerDriverSetTimerPeriod (
 132   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 133   IN UINT64                   TimerPeriod
 134   )
 135 ;
 136
 137 /**
 138
 139   This function retrieves the period of timer interrupts in 100 ns units,
 140   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 141   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 142   returned, then the timer is currently disabled.
 143
 144
 145   @param This            The EFI_TIMER_ARCH_PROTOCOL instance.
 146   @param TimerPeriod     A pointer to the timer period to retrieve in 100 ns units.  If
 147                          0 is returned, then the timer is currently disabled.
 148
 149   @retval EFI_SUCCESS            The timer period was returned in TimerPeriod.
 150   @retval EFI_INVALID_PARAMETER  TimerPeriod is NULL.
 151
 152 **/
 153 EFI_STATUS
 154 EFIAPI
 155 TimerDriverGetTimerPeriod (
 156   IN EFI_TIMER_ARCH_PROTOCOL   *This,
 157   OUT UINT64                   *TimerPeriod
 158   )
 159 ;
 160
 161 /**
 162
 163   This function generates a soft timer interrupt. If the platform does not support soft
 164   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 165   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 166   service, then a soft timer interrupt will be generated. If the timer interrupt is
 167   enabled when this service is called, then the registered handler will be invoked. The
 168   registered handler should not be able to distinguish a hardware-generated timer
 169   interrupt from a software-generated timer interrupt.
 170
 171
 172   @param This              The EFI_TIMER_ARCH_PROTOCOL instance.
 173
 174   @retval EFI_SUCCESS       The soft timer interrupt was generated.
 175   @retval EFI_UNSUPPORTEDT  The platform does not support the generation of soft timer interrupts.
 176
 177 **/
 178 EFI_STATUS
 179 EFIAPI
 180 TimerDriverGenerateSoftInterrupt (
 181   IN EFI_TIMER_ARCH_PROTOCOL  *This
 182   )
 183 ;
 184
 185 #endif