osd-contiki/cpu/pico-rv32/dev/clock.c
2016-04-15 09:54:44 +02:00

221 lines
6.6 KiB
C

/*
* Copyright (c) 2016, Dr. Ralf Schlatterbeck Open Source Consulting
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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.
*
* This file is part of the Contiki operating system.
*
*/
/**
* \brief This module contains PicoRV32-specific code to implement
* the Contiki core clock functions.
*
* \author Ralf Schlatterbeck <rsc@runtux.com>.
*
*/
/** \addtogroup picorv32
* @{
*/
/**
* \defgroup picorv32clock PicoRV32 clock implementation
* @{
*/
/**
* \file
* This file contains PicoRV32-specific code to implement the Contiki
* core clock functions.
*
*/
/**
* These routines define the PicoRV32-specific calls declared in
* /core/sys/clock.h CLOCK_SECOND is the number of ticks per second.
* It is defined through CONF_CLOCK_SECOND in the contiki-conf.h for
* each platform.
* The usual AVR defaults are 128 or 125 ticks per second, counting a
* prescaled CPU clock using the 8 bit timer0.
*
* clock_time_t is usually declared by the platform as an unsigned 16
* bit data type, thus intervals up to 512 or 524 seconds can be
* measured with ~8 millisecond precision.
* For longer intervals the 32 bit clock_seconds() is available.
*/
#include "sys/clock.h"
#include "sys/etimer.h"
#include <stdio.h> // FIXME
static volatile clock_time_t count;
volatile unsigned long seconds;
long sleepseconds;
/*---------------------------------------------------------------------------*/
/**
* No need to init
*/
void
clock_init(void)
{
}
/*---------------------------------------------------------------------------*/
/**
* Return the tick counter. We use the full 64bit counter which makes
* computation of seconds etc. easier later.
*/
#define MAX_MEASURE 40
static clock_time_t measure [MAX_MEASURE];
static volatile int counter = 0;
void print_clocks (void)
{
static int done = 0;
int i;
clock_time_t big = 0x1234567890098765LL;
if (done || counter < MAX_MEASURE) {
return;
}
for (i=0; i<counter; i++) {
clock_time_t tmp = measure [i];
uint32_t *p = (uint32_t *)(measure + i);
printf (">%016llx< ", tmp);
printf (">>%08lx%08lx<< ", (uint32_t)(tmp>>32), (uint32_t)tmp);
printf (">>>%08lx%08lx<<<\n", p [1], p [0]); /* little endian */
}
printf ("counter: %d\n", counter);
printf ("Sizes: %u %u\n", sizeof (uint32_t), sizeof (clock_time_t));
printf ("Test: %016llx\n", big);
printf ("Test: %08lx%08lx\n", (uint32_t)(big>>32), (uint32_t)big);
if (counter == MAX_MEASURE) {
done = 1;
}
}
clock_time_t
clock_time(void)
{
clock_time_t tmp;
int i = counter;
asm ("1: rdcycleh t1\n"
"rdcycle t0\n"
"rdcycleh t2\n"
"bne t1,t2,1b\n"
"sw t0,0(%1)\n"
"sw t0,4(%1)\n"
: "=r" (tmp)
: "r" (&tmp)
: "t0", "t1", "t2"
);
if (i < MAX_MEASURE) {
measure [i++] = tmp;
counter = i;
}
return tmp;
}
/*---------------------------------------------------------------------------*/
/**
* Return seconds, default is time since startup.
* The comparison avoids the need to disable clock interrupts for an atomic
* read of the four-byte variable.
*/
unsigned long
clock_seconds(void)
{
unsigned long tmp;
do {
tmp = seconds;
} while(tmp != seconds);
return tmp;
}
/*---------------------------------------------------------------------------*/
/**
* Set seconds, e.g. to a standard epoch for an absolute date/time.
*/
void
clock_set_seconds(unsigned long sec)
{
seconds = sec;
}
/*---------------------------------------------------------------------------*/
/*
* Wait for a number of clock ticks.
*/
void
clock_wait(clock_time_t t)
{
clock_time_t endticks = clock_time() + t;
while (clock_time () < endticks)
{;}
}
/*---------------------------------------------------------------------------*/
void
clock_delay_usec(uint16_t dt)
{
}
/*---------------------------------------------------------------------------*/
/**
* Delay up to 65535 milliseconds.
* \param howlong How many milliseconds to delay.
*
* Neither interrupts nor the watchdog timer is disabled over the delay.
* Platforms are not required to implement this call.
* \note This will break for CPUs clocked above 260 MHz.
*/
void
clock_delay_msec(uint16_t howlong)
{
#if F_CPU>=16000000
while(howlong--) clock_delay_usec(1000);
#elif F_CPU>=8000000
uint16_t i=996;
while(howlong--) {clock_delay_usec(i);i=999;}
#elif F_CPU>=4000000
uint16_t i=992;
while(howlong--) {clock_delay_usec(i);i=999;}
#elif F_CPU>=2000000
uint16_t i=989;
while(howlong--) {clock_delay_usec(i);i=999;}
#else
uint16_t i=983;
while(howlong--) {clock_delay_usec(i);i=999;}
#endif
}
/*---------------------------------------------------------------------------*/
/**
* Adjust the system current clock time.
* \param howmany How many ticks to add
*
* Typically used to add ticks after an MCU sleep
* clock_seconds will increment if necessary to reflect the tick addition.
* Leap ticks or seconds can (rarely) be introduced if the ISR is not blocked.
*/
void
clock_adjust_ticks(clock_time_t howmany)
{
}
/** @} */
/** @} */