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/* mbed Microcontroller Library
* Copyright (c) 2006-2013 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stddef.h>
#include "us_ticker_api.h"
#include "PeripheralNames.h"
#include "fsl_pit_hal.h"
#include "fsl_sim_hal.h"
#include "fsl_clock_manager.h"
static int us_ticker_inited = 0;
void us_ticker_init(void) {
if (us_ticker_inited) {
return;
}
us_ticker_inited = 1;
//Common for ticker/timer
uint32_t busClock;
CLOCK_SYS_EnablePitClock(0);
PIT_HAL_Enable(PIT_BASE);
CLOCK_SYS_GetFreq(kBusClock, &busClock);
//Timer
PIT_HAL_SetTimerPeriodByCount(PIT_BASE, 0, busClock / 1000000 - 1);
PIT_HAL_SetTimerPeriodByCount(PIT_BASE, 1, 0xFFFFFFFF);
PIT_HAL_SetTimerChainCmd(PIT_BASE, 1, true);
PIT_HAL_StartTimer(PIT_BASE, 0);
PIT_HAL_StartTimer(PIT_BASE, 1);
//Ticker
PIT_HAL_SetTimerPeriodByCount(PIT_BASE, 2, busClock / 1000000 - 1);
PIT_HAL_SetTimerChainCmd(PIT_BASE, 3, true);
NVIC_SetVector(PIT3_IRQn, (uint32_t)us_ticker_irq_handler);
NVIC_EnableIRQ(PIT3_IRQn);
}
uint32_t us_ticker_read() {
if (!us_ticker_inited) {
us_ticker_init();
}
return ~(PIT_HAL_ReadTimerCount(PIT_BASE, 1));
}
void us_ticker_disable_interrupt(void) {
PIT_HAL_SetIntCmd(PIT_BASE, 3, false);
}
void us_ticker_clear_interrupt(void) {
PIT_HAL_ClearIntFlag(PIT_BASE, 3);
}
void us_ticker_set_interrupt(timestamp_t timestamp) {
int delta = (int)(timestamp - us_ticker_read());
if (delta <= 0) {
// This event was in the past:
us_ticker_irq_handler();
return;
}
PIT_HAL_StopTimer(PIT_BASE, 3);
PIT_HAL_StopTimer(PIT_BASE, 2);
PIT_HAL_SetTimerPeriodByCount(PIT_BASE, 3, (uint32_t)delta);
PIT_HAL_SetIntCmd(PIT_BASE, 3, true);
PIT_HAL_StartTimer(PIT_BASE, 3);
PIT_HAL_StartTimer(PIT_BASE, 2);
}
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