1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
|
/*
* (C) Copyright 2008,2009
* Graeme Russ, <graeme.russ@gmail.com>
*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <malloc.h>
#include <asm/io.h>
#include <asm/i8254.h>
#include <asm/ibmpc.h>
struct timer_isr_function {
struct timer_isr_function *next;
timer_fnc_t *isr_func;
};
static struct timer_isr_function *first_timer_isr = NULL;
static volatile unsigned long system_ticks = 0;
/*
* register_timer_isr() allows multiple architecture and board specific
* functions to be called every millisecond. Keep the execution time of
* each function as low as possible
*/
int register_timer_isr (timer_fnc_t *isr_func)
{
struct timer_isr_function *new_func;
struct timer_isr_function *temp;
int flag;
new_func = malloc(sizeof(struct timer_isr_function));
if (new_func == NULL)
return 1;
new_func->isr_func = isr_func;
new_func->next = NULL;
/*
* Don't allow timer interrupts while the
* linked list is being modified
*/
flag = disable_interrupts ();
if (first_timer_isr == NULL) {
first_timer_isr = new_func;
} else {
temp = first_timer_isr;
while (temp->next != NULL)
temp = temp->next;
temp->next = new_func;
}
if (flag)
enable_interrupts ();
return 0;
}
/*
* timer_isr() MUST be the registered interrupt handler for
*/
void timer_isr(void *unused)
{
struct timer_isr_function *temp = first_timer_isr;
system_ticks++;
/* Execute each registered function */
while (temp != NULL) {
temp->isr_func ();
temp = temp->next;
}
}
void reset_timer (void)
{
system_ticks = 0;
}
ulong get_timer (ulong base)
{
return (system_ticks - base);
}
void set_timer (ulong t)
{
system_ticks = t;
}
|
