OvmfPkg/8254TimerDxe/Timer.h

   1 /** @file
   2   Private data structures
   3
   4 Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6 **/
   7
   8 #ifndef _TIMER_H_
   9 #define _TIMER_H_
  10
  11 #include <PiDxe.h>
  12
  13 #include <Protocol/Cpu.h>
  14 #include <Protocol/Legacy8259.h>
  15 #include <Protocol/Timer.h>
  16
  17 #include <Library/UefiBootServicesTableLib.h>
  18 #include <Library/BaseLib.h>
  19 #include <Library/DebugLib.h>
  20 #include <Library/IoLib.h>
  21
  22 //
  23 // The PCAT 8253/8254 has an input clock at 1.193182 MHz and Timer 0 is
  24 // initialized as a 16 bit free running counter that generates an interrupt(IRQ0)
  25 // each time the counter rolls over.
  26 //
  27 //   65536 counts
  28 // ---------------- * 1,000,000 uS/S = 54925.4 uS = 549254 * 100 ns
  29 //   1,193,182 Hz
  30 //
  31
  32 //
  33 // The maximum tick duration for 8254 timer
  34 //
  35 #define MAX_TIMER_TICK_DURATION  549254
  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 /**
  48   Initialize the Timer Architectural Protocol driver
  49
  50   @param ImageHandle     ImageHandle of the loaded driver
  51   @param SystemTable     Pointer to the System Table
  52
  53   @retval EFI_SUCCESS            Timer Architectural Protocol created
  54   @retval EFI_OUT_OF_RESOURCES   Not enough resources available to initialize driver.
  55   @retval EFI_DEVICE_ERROR       A device error occurred attempting to initialize the driver.
  56
  57 **/
  58 EFI_STATUS
  59 EFIAPI
  60 TimerDriverInitialize (
  61   IN EFI_HANDLE        ImageHandle,
  62   IN EFI_SYSTEM_TABLE  *SystemTable
  63   )
  64 ;
  65
  66 /**
  67
  68   This function adjusts the period of timer interrupts to the value specified
  69   by TimerPeriod.  If the timer period is updated, then the selected timer
  70   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
  71   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
  72   If an error occurs while attempting to update the timer period, then the
  73   timer hardware will be put back in its state prior to this call, and
  74   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
  75   is disabled.  This is not the same as disabling the CPU's interrupts.
  76   Instead, it must either turn off the timer hardware, or it must adjust the
  77   interrupt controller so that a CPU interrupt is not generated when the timer
  78   interrupt fires.
  79
  80
  81   @param This            The EFI_TIMER_ARCH_PROTOCOL instance.
  82   @param NotifyFunction  The rate to program the timer interrupt in 100 nS units.  If
  83                          the timer hardware is not programmable, then EFI_UNSUPPORTED is
  84                          returned.  If the timer is programmable, then the timer period
  85                          will be rounded up to the nearest timer period that is supported
  86                          by the timer hardware.  If TimerPeriod is set to 0, then the
  87                          timer interrupts will be disabled.
  88
  89   @retval        EFI_SUCCESS       The timer period was changed.
  90   @retval        EFI_UNSUPPORTED   The platform cannot change the period of the timer interrupt.
  91   @retval        EFI_DEVICE_ERROR  The timer period could not be changed due to a device error.
  92
  93 **/
  94 EFI_STATUS
  95 EFIAPI
  96 TimerDriverRegisterHandler (
  97   IN EFI_TIMER_ARCH_PROTOCOL  *This,
  98   IN EFI_TIMER_NOTIFY         NotifyFunction
  99   )
 100 ;
 101
 102 /**
 103
 104   This function adjusts the period of timer interrupts to the value specified
 105   by TimerPeriod.  If the timer period is updated, then the selected timer
 106   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
 107   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
 108   If an error occurs while attempting to update the timer period, then the
 109   timer hardware will be put back in its state prior to this call, and
 110   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 111   is disabled.  This is not the same as disabling the CPU's interrupts.
 112   Instead, it must either turn off the timer hardware, or it must adjust the
 113   interrupt controller so that a CPU interrupt is not generated when the timer
 114   interrupt fires.
 115
 116
 117   @param This            The EFI_TIMER_ARCH_PROTOCOL instance.
 118   @param TimerPeriod     The rate to program the timer interrupt in 100 nS units.  If
 119                          the timer hardware is not programmable, then EFI_UNSUPPORTED is
 120                          returned.  If the timer is programmable, then the timer period
 121                          will be rounded up to the nearest timer period that is supported
 122                          by the timer hardware.  If TimerPeriod is set to 0, then the
 123                          timer interrupts will be disabled.
 124
 125   @retval        EFI_SUCCESS       The timer period was changed.
 126   @retval        EFI_UNSUPPORTED   The platform cannot change the period of the timer interrupt.
 127   @retval        EFI_DEVICE_ERROR  The timer period could not be changed due to a device error.
 128
 129 **/
 130 EFI_STATUS
 131 EFIAPI
 132 TimerDriverSetTimerPeriod (
 133   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 134   IN UINT64                   TimerPeriod
 135   )
 136 ;
 137
 138 /**
 139
 140   This function retrieves the period of timer interrupts in 100 ns units,
 141   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 142   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 143   returned, then the timer is currently disabled.
 144
 145
 146   @param This            The EFI_TIMER_ARCH_PROTOCOL instance.
 147   @param TimerPeriod     A pointer to the timer period to retrieve in 100 ns units.  If
 148                          0 is returned, then the timer is currently disabled.
 149
 150   @retval EFI_SUCCESS            The timer period was returned in TimerPeriod.
 151   @retval EFI_INVALID_PARAMETER  TimerPeriod is NULL.
 152
 153 **/
 154 EFI_STATUS
 155 EFIAPI
 156 TimerDriverGetTimerPeriod (
 157   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 158   OUT UINT64                  *TimerPeriod
 159   )
 160 ;
 161
 162 /**
 163
 164   This function generates a soft timer interrupt. If the platform does not support soft
 165   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 166   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 167   service, then a soft timer interrupt will be generated. If the timer interrupt is
 168   enabled when this service is called, then the registered handler will be invoked. The
 169   registered handler should not be able to distinguish a hardware-generated timer
 170   interrupt from a software-generated timer interrupt.
 171
 172
 173   @param This              The EFI_TIMER_ARCH_PROTOCOL instance.
 174
 175   @retval EFI_SUCCESS       The soft timer interrupt was generated.
 176   @retval EFI_UNSUPPORTED   The platform does not support the generation of soft timer interrupts.
 177
 178 **/
 179 EFI_STATUS
 180 EFIAPI
 181 TimerDriverGenerateSoftInterrupt (
 182   IN EFI_TIMER_ARCH_PROTOCOL  *This
 183   )
 184 ;
 185
 186 #endif