osd-contiki/cpu/arm/aducrf101/clock.c
2014-07-23 16:21:53 -04:00

92 lines
3 KiB
C

/**
* Copyright (c) 2014, Analog Devices, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted (subject to the limitations in the
* disclaimer below) provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* - Neither the name of Analog Devices, Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE
* GRANTED BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT
* HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \author Jim Paris <jim.paris@rigado.com>
*/
#include <aducrf101-contiki.h>
#include <sys/clock.h>
#include <sys/etimer.h>
static volatile clock_time_t current_clock = 0;
static volatile unsigned long current_seconds = 0;
static unsigned int second_countdown = CLOCK_SECOND;
void
SysTick_Handler(void)
{
current_clock++;
if(etimer_pending()) {
etimer_request_poll();
}
if(--second_countdown == 0) {
current_seconds++;
second_countdown = CLOCK_SECOND;
}
}
/*---------------------------------------------------------------------------*/
void
clock_init()
{
SysTick_Config(F_CPU / CLOCK_SECOND);
}
/*---------------------------------------------------------------------------*/
clock_time_t
clock_time(void)
{
return current_clock;
}
/*---------------------------------------------------------------------------*/
unsigned long
clock_seconds(void)
{
return current_seconds;
}
/*---------------------------------------------------------------------------*/
void
clock_delay_usec(uint16_t usec)
{
/* Delay by watching the SysTick value change. */
int32_t remaining = (int32_t)usec * F_CPU / 1000000;
int32_t old = SysTick->VAL;
while(remaining > 0) {
int32_t new = SysTick->VAL;
if(new > old) { /* wraparound */
old += SysTick->LOAD;
}
remaining -= (old - new);
old = new;
}
}