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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 <time.h>
#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <semaphore.h>
#include "config.h"
#include "system.h"
#include "button.h"
#include "audio.h"
#include "panic.h"
static sem_t wfi_sem;
/*
* call tick tasks and wake the scheduler up */
void timer_signal(int sig)
{
(void)sig;
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)
{
sem_wait(&wfi_sem);
}
void interrupt(void)
{
int s;
/* unless idling, we usually have more interrupt() than wait_for_interrupt()
* don't post unecessarily because wait_for_interrupt() would need to
* decrement for each wasted sem_post(), instead of sleeping directly */
sem_getvalue(&wfi_sem, &s);
if (s <= 0)
sem_post(&wfi_sem);
}
/*
* setup a hrtimer to send a signal to our process every tick */
void tick_start(unsigned int interval_in_ms)
{
int ret = 0;
sigset_t proc_set;
timer_t timerid;
struct itimerspec ts;
sigevent_t sigev = {
.sigev_notify = SIGEV_SIGNAL,
.sigev_signo = SIGUSR2,
};
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 signal handler */
signal(SIGUSR2, timer_signal);
/* add the timer */
ret |= timer_create(CLOCK_REALTIME, &sigev, &timerid);
ret |= timer_settime(timerid, 0, &ts, NULL);
/* unblock SIGUSR2 so the handler can run */
ret |= sigprocmask(0, NULL, &proc_set);
ret |= sigdelset(&proc_set, SIGUSR2);
ret |= sigprocmask(SIG_SETMASK, &proc_set, NULL);
ret |= sem_init(&wfi_sem, 0, 0);
if (ret != 0)
panicf("%s(): %s\n", __func__, strerror(errno));
}
bool timer_register(int reg_prio, void (*unregister_callback)(void),
long cycles, void (*timer_callback)(void))
{
(void)reg_prio;
(void)unregister_callback;
(void)cycles;
(void)timer_callback;
return false;
}
bool timer_set_period(long cycles)
{
(void)cycles;
return false;
}
void timer_unregister(void)
{
}
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