mirror of
https://github.com/oliverschmidt/contiki.git
synced 2024-11-12 03:04:57 +00:00
40f49948e6
This commit adds cpu, platform and example files, providing support for running Contiki on TI's cc2538 DK
228 lines
6.9 KiB
C
228 lines
6.9 KiB
C
/*
|
|
* Copyright (c) 2012, Texas Instruments Incorporated - http://www.ti.com/
|
|
* 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 copyright holder 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 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 HOLDER 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.
|
|
*/
|
|
/**
|
|
* \addtogroup cc2538
|
|
* @{
|
|
*
|
|
* \defgroup cc2538-clock cc2538 Clock
|
|
*
|
|
* Implementation of the clock module for the cc2538
|
|
*
|
|
* To implement the clock functionality, we use the SysTick peripheral on the
|
|
* cortex-M3. We run the system clock at 16 MHz and we set the SysTick to give
|
|
* us 128 interrupts / sec
|
|
* @{
|
|
*
|
|
* \file
|
|
* Clock driver implementation for the TI cc2538
|
|
*/
|
|
#include "contiki.h"
|
|
#include "systick.h"
|
|
#include "reg.h"
|
|
#include "cpu.h"
|
|
#include "dev/gptimer.h"
|
|
#include "dev/sys-ctrl.h"
|
|
|
|
#include "sys/energest.h"
|
|
|
|
#include <stdint.h>
|
|
/*---------------------------------------------------------------------------*/
|
|
#define RELOAD_VALUE (125000 - 1) /** Fire 128 times / sec */
|
|
|
|
static volatile clock_time_t count;
|
|
static volatile unsigned long secs = 0;
|
|
static volatile uint8_t second_countdown = CLOCK_SECOND;
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* \brief Arch-specific implementation of clock_init for the cc2538
|
|
*
|
|
* We initialise the SysTick to fire 128 interrupts per second, giving us a
|
|
* value of 128 for CLOCK_SECOND
|
|
*
|
|
* We also initialise GPT0:Timer A, which is used by clock_delay_usec().
|
|
* We use 16-bit range (individual), count-down, one-shot, no interrupts.
|
|
* The system clock is at 16MHz giving us 62.5 nano sec ticks for Timer A.
|
|
* Prescaled by 16 gives us a very convenient 1 tick per usec
|
|
*/
|
|
void
|
|
clock_init(void)
|
|
{
|
|
count = 0;
|
|
|
|
REG(SYSTICK_STRELOAD) = RELOAD_VALUE;
|
|
|
|
/* System clock source, Enable */
|
|
REG(SYSTICK_STCTRL) |= SYSTICK_STCTRL_CLK_SRC | SYSTICK_STCTRL_ENABLE;
|
|
|
|
/* Enable the SysTick Interrupt */
|
|
REG(SYSTICK_STCTRL) |= SYSTICK_STCTRL_INTEN;
|
|
|
|
/*
|
|
* Remove the clock gate to enable GPT0 and then initialise it
|
|
* We only use GPT0 for clock_delay_usec. We initialise it here so we can
|
|
* have it ready when it's needed
|
|
*/
|
|
REG(SYS_CTRL_RCGCGPT) |= SYS_CTRL_RCGCGPT_GPT0;
|
|
|
|
/* Make sure GPT0 is off */
|
|
REG(GPT_0_BASE | GPTIMER_CTL) = 0;
|
|
|
|
|
|
/* 16-bit */
|
|
REG(GPT_0_BASE | GPTIMER_CFG) = 0x04;
|
|
|
|
/* One-Shot, Count Down, No Interrupts */
|
|
REG(GPT_0_BASE | GPTIMER_TAMR) = GPTIMER_TAMR_TAMR_ONE_SHOT;
|
|
|
|
/* Prescale by 16 (thus, value 15 in TAPR) */
|
|
REG(GPT_0_BASE | GPTIMER_TAPR) = 0x0F;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
CCIF clock_time_t
|
|
clock_time(void)
|
|
{
|
|
return count;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
clock_set_seconds(unsigned long sec)
|
|
{
|
|
secs = sec;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
CCIF unsigned long
|
|
clock_seconds(void)
|
|
{
|
|
return secs;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
clock_wait(clock_time_t i)
|
|
{
|
|
clock_time_t start;
|
|
|
|
start = clock_time();
|
|
while(clock_time() - start < (clock_time_t)i);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* \brief Arch-specific implementation of clock_delay_usec for the cc2538
|
|
* \param len Delay \e len uSecs
|
|
*
|
|
* See clock_init() for GPT0 Timer A's configuration
|
|
*/
|
|
void
|
|
clock_delay_usec(uint16_t len)
|
|
{
|
|
REG(GPT_0_BASE | GPTIMER_TAILR) = len;
|
|
REG(GPT_0_BASE | GPTIMER_CTL) |= GPTIMER_CTL_TAEN;
|
|
|
|
/* One-Shot mode: TAEN will be cleared when the timer reaches 0 */
|
|
while(REG(GPT_0_BASE | GPTIMER_CTL) & GPTIMER_CTL_TAEN);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* \brief Obsolete delay function but we implement it here since some code
|
|
* still uses it
|
|
*/
|
|
void
|
|
clock_delay(unsigned int i)
|
|
{
|
|
clock_delay_usec(i);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* \brief Adjust the clock by moving it forward by a number of ticks
|
|
* \param ticks The number of ticks
|
|
*
|
|
* This function is useful when coming out of PM1/2, during which the system
|
|
* clock is stopped. We adjust the clock by moving it forward by a number of
|
|
* ticks equal to the deep sleep duration. We update the seconds counter if
|
|
* we have to and we also do some housekeeping so that the next second will
|
|
* increment when it is meant to.
|
|
*
|
|
* \note This function is only meant to be used by lpm_exit(). Applications
|
|
* should really avoid calling this
|
|
*/
|
|
void
|
|
clock_adjust(clock_time_t ticks)
|
|
{
|
|
/* Halt the SysTick while adjusting */
|
|
REG(SYSTICK_STCTRL) &= ~SYSTICK_STCTRL_ENABLE;
|
|
|
|
/* Moving forward by more than a second? */
|
|
secs += ticks >> 7;
|
|
|
|
/* Increment tick count */
|
|
count += ticks;
|
|
|
|
/*
|
|
* Update internal second countdown so that next second change will actually
|
|
* happen when it's meant to happen.
|
|
*/
|
|
second_countdown -= ticks;
|
|
|
|
if(second_countdown == 0 || second_countdown > 128) {
|
|
secs++;
|
|
second_countdown -= 128;
|
|
}
|
|
|
|
/* Re-Start the SysTick */
|
|
REG(SYSTICK_STCTRL) |= SYSTICK_STCTRL_ENABLE;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/**
|
|
* \brief The clock Interrupt Service Routine. It polls the etimer process
|
|
* if an etimer has expired. It also updates the software clock tick and
|
|
* seconds counter since reset.
|
|
*/
|
|
void
|
|
clock_isr(void)
|
|
{
|
|
ENERGEST_ON(ENERGEST_TYPE_IRQ);
|
|
count++;
|
|
if(etimer_pending()) {
|
|
etimer_request_poll();
|
|
}
|
|
|
|
if(--second_countdown == 0) {
|
|
secs++;
|
|
second_countdown = CLOCK_SECOND;
|
|
}
|
|
ENERGEST_OFF(ENERGEST_TYPE_IRQ);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
|
|
/**
|
|
* @}
|
|
* @}
|
|
*/
|