2 * (C) Copyright 2008,2009
3 * Graeme Russ, <graeme.russ@gmail.com>
6 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
8 * See file CREDITS for list of people who contributed to this
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation; either version 2 of
14 * the License, or (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
30 #include <asm/i8254.h>
31 #include <asm/ibmpc.h>
33 struct timer_isr_function {
34 struct timer_isr_function *next;
35 timer_fnc_t *isr_func;
38 static struct timer_isr_function *first_timer_isr;
39 static unsigned long system_ticks;
40 static uint64_t base_value;
43 * register_timer_isr() allows multiple architecture and board specific
44 * functions to be called every millisecond. Keep the execution time of
45 * each function as low as possible
47 int register_timer_isr(timer_fnc_t *isr_func)
49 struct timer_isr_function *new_func;
50 struct timer_isr_function *temp;
53 new_func = malloc(sizeof(struct timer_isr_function));
58 new_func->isr_func = isr_func;
59 new_func->next = NULL;
62 * Don't allow timer interrupts while the
63 * linked list is being modified
65 flag = disable_interrupts();
67 if (first_timer_isr == NULL) {
68 first_timer_isr = new_func;
70 temp = first_timer_isr;
71 while (temp->next != NULL)
73 temp->next = new_func;
83 * timer_isr() MUST be the registered interrupt handler for
85 void timer_isr(void *unused)
87 struct timer_isr_function *temp = first_timer_isr;
91 /* Execute each registered function */
92 while (temp != NULL) {
98 ulong get_timer(ulong base)
100 return system_ticks - base;
103 void timer_set_tsc_base(uint64_t new_base)
105 base_value = new_base;
108 uint64_t timer_get_tsc(void)
114 base_value = time_now;
116 return time_now - base_value;