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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (c) 2010 Thomas Martitz
*
* 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <stdlib.h>
#include <time.h>
#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <pthread.h>
#include "config.h"
#include "system.h"
#include "kernel.h"
#include "button.h"
#include "audio.h"
#include "panic.h"
#include "timer.h"
/* Forward-declaration */
void interrupt(void);
static pthread_cond_t wfi_cond = PTHREAD_COND_INITIALIZER;
static pthread_mutex_t wfi_mtx = PTHREAD_MUTEX_INITIALIZER;
/*
* call tick tasks and wake the scheduler up */
void timer_signal(union sigval arg)
{
(void)arg;
call_tick_tasks();
interrupt();
}
/*
* wait on the sem which the signal handler posts to save cpu time (aka sleep)
*
* other mechanisms could use them as well */
void wait_for_interrupt(void)
{
pthread_cond_wait(&wfi_cond, &wfi_mtx);
}
/*
* Wakeup the kernel, if sleeping (shall not be called from a signal handler) */
void interrupt(void)
{
pthread_cond_signal(&wfi_cond);
}
/*
* setup a hrtimer to send a signal to our process every tick
*
* WARNING for Android: JNI calls are not permitted from tick tasks, as the
* underlying thread is not attached to the Java VM
*
* Can be possibly be attached if it really needs to be. but let's
* keep this leightweight
*/
void tick_start(unsigned int interval_in_ms)
{
int ret = 0;
timer_t timerid;
struct itimerspec ts;
sigevent_t sigev;
/* initializing in the declaration causes some weird warnings */
memset(&sigev, 0, sizeof(sigevent_t));
sigev.sigev_notify = SIGEV_THREAD,
sigev.sigev_notify_function = timer_signal;
ts.it_value.tv_sec = ts.it_interval.tv_sec = 0;
ts.it_value.tv_nsec = ts.it_interval.tv_nsec = interval_in_ms*1000*1000;
/* add the timer */
ret |= timer_create(CLOCK_REALTIME, &sigev, &timerid);
ret |= timer_settime(timerid, 0, &ts, NULL);
/* Grab the mutex already now and leave it to this thread. We don't
* care about race conditions when signaling the condition (because
* they are not critical), but a mutex is necessary due to the API */
pthread_mutex_lock(&wfi_mtx);
if (ret != 0)
panicf("%s(): %s\n", __func__, strerror(errno));
}
#define cycles_to_microseconds(cycles) \
((int)((10000*cycles)/(TIMER_FREQ / 100)))
static timer_t timer_tid;
static int timer_prio = -1;
void (*global_unreg_callback)(void);
void (*global_timer_callback)(void);
static void timer_cb(union sigval arg)
{
/* check for spurious callbacks [arg.sival_ptr] */
if (global_timer_callback && global_timer_callback == arg.sival_ptr)
global_timer_callback();
}
bool timer_register(int reg_prio, void (*unregister_callback)(void),
long cycles, void (*timer_callback)(void))
{
int ret = 0;
struct itimerspec ts;
sigevent_t sigev;
long in_us = cycles_to_microseconds(cycles);
if (reg_prio <= timer_prio || in_us <= 0)
return false;
if(timer_prio >= 0)
{
if (global_unreg_callback) /* timer has callback user needs to unreg */
global_unreg_callback();
else /* no callback -- delete timer */
timer_delete(timer_tid);
}
memset(&sigev, 0, sizeof(sigevent_t));
sigev.sigev_notify = SIGEV_THREAD,
sigev.sigev_notify_function = timer_cb;
sigev.sigev_value.sival_ptr = timer_callback; /* store cb to check later */
div_t q = div(in_us, 1000000);
ts.it_value.tv_sec = ts.it_interval.tv_sec = q.quot;
ts.it_value.tv_nsec = ts.it_interval.tv_nsec = q.rem*1000;
/* add the timer */
ret |= timer_create(CLOCK_REALTIME, &sigev, &timer_tid);
ret |= timer_settime(timer_tid, 0, &ts, NULL);
global_timer_callback = timer_callback;
global_unreg_callback = unregister_callback;
timer_prio = reg_prio;
return ret == 0;
}
bool timer_set_period(long cycles)
{
struct itimerspec ts;
long in_us = cycles_to_microseconds(cycles);
div_t q = div(in_us, 1000000);
ts.it_value.tv_sec = ts.it_interval.tv_sec = q.quot;
ts.it_value.tv_nsec = ts.it_interval.tv_nsec = q.rem*1000;
return timer_settime(timer_tid, 0, &ts, NULL) == 0;
}
void timer_unregister(void)
{
timer_delete(timer_tid);
timer_prio = -1;
global_unreg_callback = NULL;
global_timer_callback = NULL;
}
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