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removed posix real-time extension timers from cpu

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This commit is contained in:
Ludwig Ortmann 2013-04-03 18:53:19 +02:00
parent 671cb6560f
commit 2f74d35709
2 changed files with 96 additions and 49 deletions
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141
cpu/native/hwtimer_cpu.c
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@ -1,8 +1,11 @@
/**
* Native CPU hwtimer_arch.h implementation
*
* Uses POSIX real-time extension timers to mimic hardware timers.
* XXX: see hwtimer_isr_timer()
* Uses POSIX realtime clock and POSIX itimer to mimic hardware.
* Since there is only 1 itmer per process and RIOT needs several
* hardware timers, hwtimers are being multiplexed onto the itimer.
*
* XXX: does not scale well with number of timers (overhead: O(N)).
*
* Copyright (C) 2013 Ludwig Ortmann
*
@ -18,6 +21,7 @@
*/
#include <time.h>
#include <sys/time.h>
#include <signal.h>
#include <stdint.h>
#include <err.h>
@ -31,17 +35,30 @@
#include "debug.h"
static unsigned long native_hwtimer_now;
static int native_hwtimer_irq[ARCH_MAXTIMERS];
static timer_t native_hwtimer_timer[ARCH_MAXTIMERS];
static struct itimerval native_hwtimer[ARCH_MAXTIMERS];
static int native_hwtimer_isset[ARCH_MAXTIMERS];
static int next_timer;
static void (*int_handler)(int);
/**
* sets timespec to given ticks
* sets timeval to given ticks
*/
void ticks2ts(unsigned long ticks, struct timespec *tp)
void ticks2tv(unsigned long ticks, struct timeval *tp)
{
tp->tv_sec = ticks / HWTIMER_SPEED;
tp->tv_nsec = (ticks % HWTIMER_SPEED)*1000 ;
tp->tv_usec = (ticks % HWTIMER_SPEED) ;
}
/**
* returns ticks for give timeval
*/
unsigned long tv2ticks(struct timeval *tp)
{
/* TODO: check for overflow */
return((tp->tv_sec * HWTIMER_SPEED) + (tp->tv_usec));
}
/**
@ -54,22 +71,72 @@ unsigned long ts2ticks(struct timespec *tp)
}
/**
* native timer signal handler,
* set next_timer to the next lowest enabled timer index
*/
void schedule_timer(void)
{
int l = next_timer;
for (
int i = ((next_timer +1) % ARCH_MAXTIMERS);
i != next_timer;
i = ((i+1) % ARCH_MAXTIMERS)
)
{
if ( native_hwtimer_isset[l] != 1 ) {
/* make sure we dont compare to garbage in the following
* if condition */
l = i;
}
if (
( native_hwtimer_isset[i] == 1 ) &&
( tv2ticks(&(native_hwtimer[i].it_value)) < tv2ticks(&(native_hwtimer[l].it_value)) )
)
{
/* set l to the lowest active time */
l = i;
}
}
next_timer = l;
/* l could still point to some unused (garbage) timer if no timers
* are set at all */
if (native_hwtimer_isset[next_timer] == 1) {
if (setitimer(ITIMER_REAL, &native_hwtimer[next_timer], NULL) == -1) {
err(1, "schedule_timer");
}
else {
DEBUG("schedule_timer(): set next timer.\n");
}
}
else {
DEBUG("schedule_timer(): no next timer!? This looks suspicous.\n");
// TODO: unset timer.
}
}
/**
* native timer signal handler
*
* XXX: Calls callback for all timers whenever any timer finishes.
* set new system timer, call timer interrupt handler
*/
void hwtimer_isr_timer()
{
int i;
DEBUG("hwtimer_isr_timer()\n");
for (int i = 0; i<ARCH_MAXTIMERS; i++) {
if (native_hwtimer_irq[i] == 1) {
DEBUG("hwtimer_isr_timer(): calling hwtimer.int_handler(%i)\n", i);
int_handler(i);
}
if (timer_getoverrun(native_hwtimer_timer[i]) > 0 ) {
errx(1, "XXX: unhandled hwtimer situation");
}
i = next_timer;
native_hwtimer_isset[next_timer] = 0;
schedule_timer();
if (native_hwtimer_irq[i] == 1) {
DEBUG("hwtimer_isr_timer(): calling hwtimer.int_handler(%i)\n", i);
int_handler(i);
}
else {
DEBUG("hwtimer_isr_timer(): this should not have happened");
}
}
@ -93,39 +160,27 @@ void hwtimer_arch_disable_interrupt(void)
void hwtimer_arch_unset(short timer)
{
struct itimerspec its;
DEBUG("hwtimer_arch_unset(%d)\n", timer);
native_hwtimer_irq[timer] = 0;
its.it_interval.tv_nsec = 0;
its.it_interval.tv_sec = 0;
its.it_value.tv_nsec = 0;
its.it_value.tv_sec = 0;
if( (timer_settime(native_hwtimer_timer[timer], 0, &its, NULL)) == -1) {
err(1, "hwtimer_arch_unset: timer_settime");
}
native_hwtimer_isset[timer] = 0;
schedule_timer();
return;
}
void hwtimer_arch_set(unsigned long offset, short timer)
{
struct itimerspec its;
DEBUG("hwtimer_arch_set(%li, %i)\n", offset, timer);
native_hwtimer_irq[timer] = 1;
native_hwtimer_isset[timer] = 1;
ticks2ts(offset, &its.it_value);
DEBUG("hwtimer_arch_set(): that is %lis %lins from now\n", its.it_value.tv_sec, its.it_value.tv_nsec);
ticks2tv(offset, &(native_hwtimer[timer].it_value));
DEBUG("hwtimer_arch_set(): that is %lis %lius from now\n",
native_hwtimer[timer].it_value.tv_sec,
native_hwtimer[timer].it_value.tv_usec);
its.it_interval.tv_sec = 0;
its.it_interval.tv_nsec = 0;
if (timer_settime(native_hwtimer_timer[timer], 0, &its, NULL) == -1) {
err(1, "hwtimer_arch_unset: timer_settime");
}
schedule_timer();
return;
}
@ -155,24 +210,18 @@ unsigned long hwtimer_arch_now(void)
void hwtimer_arch_init(void (*handler)(int), uint32_t fcpu)
{
struct sigevent sev;
DEBUG("hwtimer_arch_init()\n");
hwtimer_arch_disable_interrupt();
int_handler = handler;
sev.sigev_notify = SIGEV_SIGNAL;
for (int i = 0; i<ARCH_MAXTIMERS; i++) {
native_hwtimer_irq[i] = 0;
//sev.sigev_signo = _SIG_TIMER + i;;
sev.sigev_signo = SIGALRM;
//sev.sigev_value.sival_ptr = &native_hwtimer_timer[i];
if (timer_create(CLOCK_REALTIME, &sev, &native_hwtimer_timer[i]) == -1) {
err(1, "timer_create");
}
native_hwtimer_isset[i] = 0;
native_hwtimer[i].it_interval.tv_sec = 0;
native_hwtimer[i].it_interval.tv_usec = 0;
}
hwtimer_arch_enable_interrupt();
return;
}

4
cpu/native/include/cpu-conf.h
View File

@ -24,9 +24,7 @@
#define KERNEL_CONF_STACKSIZE_IDLE 4096
#define NATIVE_ISR_STACKSIZE 8192
#define _SIG_UNDEF SIGRTMIN + 0
#define _SIG_TIMER SIGRTMIN + 10 // check hwtimer_cpu.h for compliance
#define _SIG_LTC4150 SIGRTMIN + 20
#define _SIG_LTC4150 SIGRTMIN + 0
/* TODO: check for overflow (SIGRTMAX) */