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/* (C) 2008 by Holger Hans Peter Freyther <zecke@selfish.org>
* (C) 2010 by Harald Welte <laforge@gnumonks.org>
* All Rights Reserved
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include <stdint.h>
#include <debug.h>
#include <osmocore/linuxlist.h>
#include <comm/timer.h>
#include <calypso/timer.h>
#include <calypso/irq.h>
#include <keypad.h>
static LLIST_HEAD(timer_list);
unsigned long volatile jiffies;
#define TIMER_HZ 100
#define time_after(a,b) \
(typecheck(unsigned long, a) && \
typecheck(unsigned long, b) && \
((long)(b) - (long)(a) < 0))
#define time_before(a,b) time_after(b,a)
void add_timer(struct timer_list *timer)
{
struct timer_list *list_timer;
/* TODO: Optimize and remember the closest item... */
timer->active = 1;
/* this might be called from within update_timers */
llist_for_each_entry(list_timer, &timer_list, entry)
if (timer == list_timer)
return;
timer->in_list = 1;
llist_add(&timer->entry, &timer_list);
}
void schedule_timer(struct timer_list *timer, int milliseconds)
{
timer->expires = jiffies + ((milliseconds * TIMER_HZ) / 1000);
add_timer(timer);
}
void del_timer(struct timer_list *timer)
{
if (timer->in_list) {
timer->active = 0;
timer->in_list = 0;
llist_del(&timer->entry);
}
}
int timer_pending(struct timer_list *timer)
{
return timer->active;
}
#if 0
/*
* if we have a nearest time return the delta between the current
* time and the time of the nearest timer.
* If the nearest timer timed out return NULL and then we will
* dispatch everything after the select
*/
struct timeval *nearest_timer()
{
struct timeval current_time;
if (s_nearest_time.tv_sec == 0 && s_nearest_time.tv_usec == 0)
return NULL;
if (gettimeofday(¤t_time, NULL) == -1)
return NULL;
unsigned long long nearestTime = s_nearest_time.tv_sec * MICRO_SECONDS + s_nearest_time.tv_usec;
unsigned long long currentTime = current_time.tv_sec * MICRO_SECONDS + current_time.tv_usec;
if (nearestTime < currentTime) {
s_select_time.tv_sec = 0;
s_select_time.tv_usec = 0;
} else {
s_select_time.tv_sec = (nearestTime - currentTime) / MICRO_SECONDS;
s_select_time.tv_usec = (nearestTime - currentTime) % MICRO_SECONDS;
}
return &s_select_time;
}
/*
* Find the nearest time and update s_nearest_time
*/
void prepare_timers()
{
struct timer_list *timer, *nearest_timer = NULL;
llist_for_each_entry(timer, &timer_list, entry) {
if (!nearest_timer || time_before(timer->expires, nearest_timer->expires)) {
nearest_timer = timer;
}
}
if (nearest_timer) {
s_nearest_time = nearest_timer->timeout;
} else {
memset(&s_nearest_time, 0, sizeof(struct timeval));
}
}
#endif
/*
* fire all timers... and remove them
*/
int update_timers(void)
{
struct timer_list *timer, *tmp;
int work = 0;
/*
* The callbacks might mess with our list and in this case
* even llist_for_each_entry_safe is not safe to use. To allow
* del_timer, add_timer, schedule_timer to be called from within
* the callback we jump through some loops.
*
* First we set the handled flag of each active timer to zero,
* then we iterate over the list and execute the callbacks. As the
* list might have been changed (specially the next) from within
* the callback we have to start over again. Once every callback
* is dispatched we will remove the non-active from the list.
*
* TODO: If this is a performance issue we can poison a global
* variable in add_timer and del_timer and only then restart.
*/
llist_for_each_entry(timer, &timer_list, entry) {
timer->handled = 0;
}
restart:
llist_for_each_entry(timer, &timer_list, entry) {
if (!timer->handled && time_before(timer->expires, jiffies)) {
timer->handled = 1;
timer->active = 0;
(*timer->cb)(timer->data);
work = 1;
goto restart;
}
}
llist_for_each_entry_safe(timer, tmp, &timer_list, entry) {
timer->handled = 0;
if (!timer->active) {
del_timer(timer);
}
}
return work;
}
int timer_check(void)
{
struct timer_list *timer;
int i = 0;
llist_for_each_entry(timer, &timer_list, entry) {
i++;
}
return i;
}
static void timer_irq(enum irq_nr irq)
{
/* we only increment jiffies here. FIXME: does this need to be atomic? */
jiffies++;
keypad_poll();
}
void timer_init(void)
{
/* configure TIMER2 for our purpose */
hwtimer_enable(2, 1);
/* The timer runs at 13MHz / 32, i.e. 406.25kHz */
#if (TIMER_HZ == 100)
hwtimer_load(2, 4062);
hwtimer_config(2, 0, 1);
#elif (TIMER_HZ == 10)
/* prescaler 4, 1015 ticks until expiry */
hwtimer_load(2, 1015);
hwtimer_config(2, 4, 1);
#endif
hwtimer_enable(2, 1);
/* register interrupt handler with default priority, EDGE triggered */
irq_register_handler(IRQ_TIMER2, &timer_irq);
irq_config(IRQ_TIMER2, 0, 1, -1);
irq_enable(IRQ_TIMER2);
}
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