From 8c63d47651f77d9fb887cad433370b866eb0a193 Mon Sep 17 00:00:00 2001 From: Graeme Russ Date: Tue, 24 Feb 2009 21:14:45 +1100 Subject: Implement SC520 timers Signed-off-by: Graeme Russ --- lib_i386/timer.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 lib_i386/timer.c (limited to 'lib_i386/timer.c') diff --git a/lib_i386/timer.c b/lib_i386/timer.c new file mode 100644 index 000000000..5cb1f54fb --- /dev/null +++ b/lib_i386/timer.c @@ -0,0 +1,107 @@ +/* + * (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 +#include +#include +#include +#include + +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; +} -- cgit v1.2.3