1/** @file
2  Private data structures
3
4Copyright (c) 2005 - 2012, Intel Corporation. All rights reserved.<BR>
5This program and the accompanying materials
6are licensed and made available under the terms and conditions of the BSD License
7which accompanies this distribution.  The full text of the license may be found at
8http://opensource.org/licenses/bsd-license.php
9
10THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11WITHOUT 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
38//
39// The maximum tick duration for 8254 timer
40//
41#define MAX_TIMER_TICK_DURATION     549254
42//
43// The default timer tick duration is set to 10 ms = 100000 100 ns units
44//
45#define DEFAULT_TIMER_TICK_DURATION 100000
46#define TIMER_CONTROL_PORT          0x43
47#define TIMER0_COUNT_PORT           0x40
48
49//
50// Function Prototypes
51//
52/**
53  Initialize the Timer Architectural Protocol driver
54
55  @param ImageHandle     ImageHandle of the loaded driver
56  @param SystemTable     Pointer to the System Table
57
58  @retval EFI_SUCCESS            Timer Architectural Protocol created
59  @retval EFI_OUT_OF_RESOURCES   Not enough resources available to initialize driver.
60  @retval EFI_DEVICE_ERROR       A device error occured attempting to initialize the driver.
61
62**/
63EFI_STATUS
64EFIAPI
65TimerDriverInitialize (
66  IN EFI_HANDLE        ImageHandle,
67  IN EFI_SYSTEM_TABLE  *SystemTable
68  )
69;
70
71/**
72
73  This function adjusts the period of timer interrupts to the value specified
74  by TimerPeriod.  If the timer period is updated, then the selected timer
75  period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
76  the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
77  If an error occurs while attempting to update the timer period, then the
78  timer hardware will be put back in its state prior to this call, and
79  EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
80  is disabled.  This is not the same as disabling the CPU's interrupts.
81  Instead, it must either turn off the timer hardware, or it must adjust the
82  interrupt controller so that a CPU interrupt is not generated when the timer
83  interrupt fires.
84
85
86  @param This            The EFI_TIMER_ARCH_PROTOCOL instance.
87  @param NotifyFunction  The rate to program the timer interrupt in 100 nS units.  If
88                         the timer hardware is not programmable, then EFI_UNSUPPORTED is
89                         returned.  If the timer is programmable, then the timer period
90                         will be rounded up to the nearest timer period that is supported
91                         by the timer hardware.  If TimerPeriod is set to 0, then the
92                         timer interrupts will be disabled.
93
94  @retval        EFI_SUCCESS       The timer period was changed.
95  @retval        EFI_UNSUPPORTED   The platform cannot change the period of the timer interrupt.
96  @retval        EFI_DEVICE_ERROR  The timer period could not be changed due to a device error.
97
98**/
99EFI_STATUS
100EFIAPI
101TimerDriverRegisterHandler (
102  IN EFI_TIMER_ARCH_PROTOCOL  *This,
103  IN EFI_TIMER_NOTIFY         NotifyFunction
104  )
105;
106
107/**
108
109  This function adjusts the period of timer interrupts to the value specified
110  by TimerPeriod.  If the timer period is updated, then the selected timer
111  period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
112  the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
113  If an error occurs while attempting to update the timer period, then the
114  timer hardware will be put back in its state prior to this call, and
115  EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
116  is disabled.  This is not the same as disabling the CPU's interrupts.
117  Instead, it must either turn off the timer hardware, or it must adjust the
118  interrupt controller so that a CPU interrupt is not generated when the timer
119  interrupt fires.
120
121
122  @param This            The EFI_TIMER_ARCH_PROTOCOL instance.
123  @param TimerPeriod     The rate to program the timer interrupt in 100 nS units.  If
124                         the timer hardware is not programmable, then EFI_UNSUPPORTED is
125                         returned.  If the timer is programmable, then the timer period
126                         will be rounded up to the nearest timer period that is supported
127                         by the timer hardware.  If TimerPeriod is set to 0, then the
128                         timer interrupts will be disabled.
129
130  @retval        EFI_SUCCESS       The timer period was changed.
131  @retval        EFI_UNSUPPORTED   The platform cannot change the period of the timer interrupt.
132  @retval        EFI_DEVICE_ERROR  The timer period could not be changed due to a device error.
133
134**/
135EFI_STATUS
136EFIAPI
137TimerDriverSetTimerPeriod (
138  IN EFI_TIMER_ARCH_PROTOCOL  *This,
139  IN UINT64                   TimerPeriod
140  )
141;
142
143/**
144
145  This function retrieves the period of timer interrupts in 100 ns units,
146  returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
147  is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
148  returned, then the timer is currently disabled.
149
150
151  @param This            The EFI_TIMER_ARCH_PROTOCOL instance.
152  @param TimerPeriod     A pointer to the timer period to retrieve in 100 ns units.  If
153                         0 is returned, then the timer is currently disabled.
154
155  @retval EFI_SUCCESS            The timer period was returned in TimerPeriod.
156  @retval EFI_INVALID_PARAMETER  TimerPeriod is NULL.
157
158**/
159EFI_STATUS
160EFIAPI
161TimerDriverGetTimerPeriod (
162  IN EFI_TIMER_ARCH_PROTOCOL   *This,
163  OUT UINT64                   *TimerPeriod
164  )
165;
166
167/**
168
169  This function generates a soft timer interrupt. If the platform does not support soft
170  timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
171  If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
172  service, then a soft timer interrupt will be generated. If the timer interrupt is
173  enabled when this service is called, then the registered handler will be invoked. The
174  registered handler should not be able to distinguish a hardware-generated timer
175  interrupt from a software-generated timer interrupt.
176
177
178  @param This              The EFI_TIMER_ARCH_PROTOCOL instance.
179
180  @retval EFI_SUCCESS       The soft timer interrupt was generated.
181  @retval EFI_UNSUPPORTEDT  The platform does not support the generation of soft timer interrupts.
182
183**/
184EFI_STATUS
185EFIAPI
186TimerDriverGenerateSoftInterrupt (
187  IN EFI_TIMER_ARCH_PROTOCOL  *This
188  )
189;
190
191#endif
192