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/**
* Native CPU lpm.h implementation
*
* Uses system calls to emulate CPU power modes.
*
* Copyright (C) 2013 Ludwig Ortmann <ludwig.ortmann@fu-berlin.de>
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License. See the file LICENSE in the top level directory for more
* details.
*
* @ingroup lpm
* @ingroup native_cpu
* @{
* @file
* @author Ludwig Ortmann <ludwig.ortmann@fu-berlin.de>
* @}
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#ifdef MODULE_UART0
#include <sys/select.h>
#include <errno.h>
#endif
#include <err.h>
#include "lpm.h"
#include "debug.h"
#include "cpu.h"
#include "native_internal.h"
#ifdef MODULE_UART0
#include "board_internal.h"
#endif
static enum lpm_mode native_lpm;
void lpm_init(void)
{
DEBUG("lpm_init()\n");
native_lpm = LPM_ON;
return;
}
void _native_lpm_sleep(void)
{
#ifdef MODULE_UART0
int nfds;
/* set fds */
FD_ZERO(&_native_rfds);
nfds = _native_set_uart_fds();
nfds++;
_native_in_syscall++; // no switching here
nfds = select(nfds, &_native_rfds, NULL, NULL, NULL);
_native_in_syscall--;
DEBUG("_native_lpm_sleep: returned: %i\n", nfds);
if (nfds != -1) {
/* uart ready, handle input */
/* TODO: switch to ISR context */
_native_handle_uart0_input();
}
else if ((errno == EAGAIN) || (errno == EWOULDBLOCK)) {
/* would block / resource unavailable .. it appears a
* contended socket can show this behavior sometimes */
_native_in_syscall++;
warn("_native_lpm_sleep: select()");
_native_in_syscall--;
return;
}
else if (errno != EINTR) {
/* select failed for reason other than signal */
err(EXIT_FAILURE, "lpm_set(): select()");
}
/* otherwise select was interrupted because of a signal, continue below */
#else
_native_in_syscall++; // no switching here
real_pause();
_native_in_syscall--;
#endif
if (_native_sigpend > 0) {
DEBUG("\n\n\t\treturn from syscall, calling native_irq_handler\n\n");
_native_in_syscall++;
_native_syscall_leave();
}
}
/**
* LPM_IDLE uses sleep() to wait for interrupts
* LPM_OFF exits process
* other modes not supported at the moment
*/
enum lpm_mode lpm_set(enum lpm_mode target)
{
enum lpm_mode last_lpm;
//DEBUG("lpm_set(%i)\n", target);
last_lpm = native_lpm;
native_lpm = target;
switch(native_lpm) { /* @contiki :-p */
case LPM_ON:
break;
case LPM_IDLE:
//DEBUG("lpm_set(): pause()\n");
//pause();
_native_lpm_sleep();
break;
/* XXX: unfinished modes: */
case LPM_SLEEP:
/*TODO: implement*/
printf("XXX: lpm_set(): LPM_SLEEP not implemented\n");
//sigsuspend();
case LPM_POWERDOWN:
/*TODO: implement*/
printf("XXX: lpm_set(): LPM_POWERDOWN not implemented\n");
//sigsuspend();
case LPM_OFF:
printf("lpm_set(): exit()\n");
exit(0);
default:
DEBUG("XXX: unsupported power mode: %i\n", native_lpm);
exit(1);
}
return last_lpm;
}
void lpm_awake(void)
{
DEBUG("XXX: lpm_awake()\n");
native_lpm = LPM_ON;
return;
}
void lpm_begin_awake(void)
{
DEBUG("XXX: lpm_begin_awake()\n");
return;
}
void lpm_end_awake(void)
{
DEBUG("XXX: lpm_end_awake()\n");
native_lpm = LPM_ON;
return;
}
enum lpm_mode lpm_get(void)
{
return native_lpm;
}