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108 lines
2.4 KiB
C
108 lines
2.4 KiB
C
/*
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* (C) Copyright 2002
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* Daniel Engström, Omicron Ceti AB, daniel@omicron.se.
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#include <common.h>
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#include <malloc.h>
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#include <asm/io.h>
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#include <asm/i8254.h>
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#include <asm/ibmpc.h>
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struct timer_isr_function {
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struct timer_isr_function *next;
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timer_fnc_t *isr_func;
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};
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static struct timer_isr_function *first_timer_isr = NULL;
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static volatile unsigned long system_ticks = 0;
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/*
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* register_timer_isr() allows multiple architecture and board specific
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* functions to be called every millisecond. Keep the execution time of
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* each function as low as possible
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*/
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int register_timer_isr (timer_fnc_t *isr_func)
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{
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struct timer_isr_function *new_func;
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struct timer_isr_function *temp;
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int flag;
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new_func = malloc(sizeof(struct timer_isr_function));
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if (new_func == NULL)
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return 1;
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new_func->isr_func = isr_func;
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new_func->next = NULL;
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/*
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* Don't allow timer interrupts while the
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* linked list is being modified
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*/
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flag = disable_interrupts ();
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if (first_timer_isr == NULL) {
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first_timer_isr = new_func;
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} else {
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temp = first_timer_isr;
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while (temp->next != NULL)
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temp = temp->next;
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temp->next = new_func;
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}
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if (flag)
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enable_interrupts ();
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return 0;
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}
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/*
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* timer_isr() MUST be the registered interrupt handler for
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*/
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void timer_isr(void *unused)
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{
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struct timer_isr_function *temp = first_timer_isr;
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system_ticks++;
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/* Execute each registered function */
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while (temp != NULL) {
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temp->isr_func ();
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temp = temp->next;
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}
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}
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void reset_timer (void)
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{
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system_ticks = 0;
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}
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ulong get_timer (ulong base)
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{
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return (system_ticks - base);
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}
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void set_timer (ulong t)
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{
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system_ticks = t;
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}
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