1 /** @file 2 Timer Architectural Protocol as defined in PI Specification VOLUME 2 DXE 3 4 This code is used to provide the timer tick for the DXE core. 5 6 Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR> 7 This program and the accompanying materials 8 are licensed and made available under the terms and conditions of the BSD License 9 which accompanies this distribution. The full text of the license may be found at 10 http://opensource.org/licenses/bsd-license.php 11 12 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 13 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 14 15 **/ 16 17 #ifndef __ARCH_PROTOCOL_TIMER_H__ 18 #define __ARCH_PROTOCOL_TIMER_H__ 19 20 /// 21 /// Global ID for the Timer Architectural Protocol 22 /// 23 #define EFI_TIMER_ARCH_PROTOCOL_GUID \ 24 { 0x26baccb3, 0x6f42, 0x11d4, {0xbc, 0xe7, 0x0, 0x80, 0xc7, 0x3c, 0x88, 0x81 } } 25 26 /// 27 /// Declare forward reference for the Timer Architectural Protocol 28 /// 29 typedef struct _EFI_TIMER_ARCH_PROTOCOL EFI_TIMER_ARCH_PROTOCOL; 30 31 /** 32 This function of this type is called when a timer interrupt fires. This 33 function executes at TPL_HIGH_LEVEL. The DXE Core will register a function 34 of this type to be called for the timer interrupt, so it can know how much 35 time has passed. This information is used to signal timer based events. 36 37 @param Time Time since the last timer interrupt in 100 ns units. This will 38 typically be TimerPeriod, but if a timer interrupt is missed, and the 39 EFI_TIMER_ARCH_PROTOCOL driver can detect missed interrupts, then Time 40 will contain the actual amount of time since the last interrupt. 41 42 None. 43 44 **/ 45 typedef 46 VOID 47 (EFIAPI *EFI_TIMER_NOTIFY)( 48 IN UINT64 Time 49 ); 50 51 /** 52 This function registers the handler NotifyFunction so it is called every time 53 the timer interrupt fires. It also passes the amount of time since the last 54 handler call to the NotifyFunction. If NotifyFunction is NULL, then the 55 handler is unregistered. If the handler is registered, then EFI_SUCCESS is 56 returned. If the CPU does not support registering a timer interrupt handler, 57 then EFI_UNSUPPORTED is returned. If an attempt is made to register a handler 58 when a handler is already registered, then EFI_ALREADY_STARTED is returned. 59 If an attempt is made to unregister a handler when a handler is not registered, 60 then EFI_INVALID_PARAMETER is returned. If an error occurs attempting to 61 register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR 62 is returned. 63 64 @param This The EFI_TIMER_ARCH_PROTOCOL instance. 65 @param NotifyFunction The function to call when a timer interrupt fires. This 66 function executes at TPL_HIGH_LEVEL. The DXE Core will 67 register a handler for the timer interrupt, so it can know 68 how much time has passed. This information is used to 69 signal timer based events. NULL will unregister the handler. 70 71 @retval EFI_SUCCESS The timer handler was registered. 72 @retval EFI_UNSUPPORTED The platform does not support timer interrupts. 73 @retval EFI_ALREADY_STARTED NotifyFunction is not NULL, and a handler is already 74 registered. 75 @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not 76 previously registered. 77 @retval EFI_DEVICE_ERROR The timer handler could not be registered. 78 79 **/ 80 typedef 81 EFI_STATUS 82 (EFIAPI *EFI_TIMER_REGISTER_HANDLER)( 83 IN EFI_TIMER_ARCH_PROTOCOL *This, 84 IN EFI_TIMER_NOTIFY NotifyFunction 85 ); 86 87 /** 88 This function adjusts the period of timer interrupts to the value specified 89 by TimerPeriod. If the timer period is updated, then the selected timer 90 period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If 91 the timer hardware is not programmable, then EFI_UNSUPPORTED is returned. 92 If an error occurs while attempting to update the timer period, then the 93 timer hardware will be put back in its state prior to this call, and 94 EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt 95 is disabled. This is not the same as disabling the CPU's interrupts. 96 Instead, it must either turn off the timer hardware, or it must adjust the 97 interrupt controller so that a CPU interrupt is not generated when the timer 98 interrupt fires. 99 100 @param This The EFI_TIMER_ARCH_PROTOCOL instance. 101 @param TimerPeriod The rate to program the timer interrupt in 100 nS units. If 102 the timer hardware is not programmable, then EFI_UNSUPPORTED is 103 returned. If the timer is programmable, then the timer period 104 will be rounded up to the nearest timer period that is supported 105 by the timer hardware. If TimerPeriod is set to 0, then the 106 timer interrupts will be disabled. 107 108 @retval EFI_SUCCESS The timer period was changed. 109 @retval EFI_UNSUPPORTED The platform cannot change the period of the timer interrupt. 110 @retval EFI_DEVICE_ERROR The timer period could not be changed due to a device error. 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 This function retrieves the period of timer interrupts in 100 ns units, 122 returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod 123 is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is 124 returned, then the timer is currently disabled. 125 126 @param This The EFI_TIMER_ARCH_PROTOCOL instance. 127 @param TimerPeriod A pointer to the timer period to retrieve in 100 ns units. If 128 0 is returned, then the timer is currently disabled. 129 130 @retval EFI_SUCCESS The timer period was returned in TimerPeriod. 131 @retval EFI_INVALID_PARAMETER TimerPeriod is NULL. 132 133 **/ 134 typedef 135 EFI_STATUS 136 (EFIAPI *EFI_TIMER_GET_TIMER_PERIOD)( 137 IN EFI_TIMER_ARCH_PROTOCOL *This, 138 OUT UINT64 *TimerPeriod 139 ); 140 141 /** 142 This function generates a soft timer interrupt. If the platform does not support soft 143 timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned. 144 If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler() 145 service, then a soft timer interrupt will be generated. If the timer interrupt is 146 enabled when this service is called, then the registered handler will be invoked. The 147 registered handler should not be able to distinguish a hardware-generated timer 148 interrupt from a software-generated timer interrupt. 149 150 @param This The EFI_TIMER_ARCH_PROTOCOL instance. 151 152 @retval EFI_SUCCESS The soft timer interrupt was generated. 153 @retval EFI_UNSUPPORTED The platform does not support the generation of soft timer interrupts. 154 155 **/ 156 typedef 157 EFI_STATUS 158 (EFIAPI *EFI_TIMER_GENERATE_SOFT_INTERRUPT)( 159 IN EFI_TIMER_ARCH_PROTOCOL *This 160 ); 161 162 163 /// 164 /// This protocol provides the services to initialize a periodic timer 165 /// interrupt, and to register a handler that is called each time the timer 166 /// interrupt fires. It may also provide a service to adjust the rate of the 167 /// periodic timer interrupt. When a timer interrupt occurs, the handler is 168 /// passed the amount of time that has passed since the previous timer 169 /// interrupt. 170 /// 171 struct _EFI_TIMER_ARCH_PROTOCOL { 172 EFI_TIMER_REGISTER_HANDLER RegisterHandler; 173 EFI_TIMER_SET_TIMER_PERIOD SetTimerPeriod; 174 EFI_TIMER_GET_TIMER_PERIOD GetTimerPeriod; 175 EFI_TIMER_GENERATE_SOFT_INTERRUPT GenerateSoftInterrupt; 176 }; 177 178 extern EFI_GUID gEfiTimerArchProtocolGuid; 179 180 #endif 181
