mirror of https://github.com/ARMmbed/mbed-os.git
130 lines
3.9 KiB
C
130 lines
3.9 KiB
C
/* mbed Microcontroller Library
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* Copyright (c) 2006-2016 ARM Limited
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <stddef.h>
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#include "us_ticker_api.h"
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#include "PeripheralNames.h"
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#include "hal_tick.h"
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// A 16-bit timer is used
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#if TIM_MST_16BIT
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TIM_HandleTypeDef TimMasterHandle;
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volatile uint32_t SlaveCounter = 0;
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volatile uint32_t oc_int_part = 0;
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volatile uint16_t oc_rem_part = 0;
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volatile uint8_t tim_it_update; // TIM_IT_UPDATE event flag set in timer_irq_handler()
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volatile uint32_t tim_it_counter = 0; // Time stamp to be updated by timer_irq_handler()
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static int us_ticker_inited = 0;
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void set_compare(uint16_t count)
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{
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TimMasterHandle.Instance = TIM_MST;
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// Set new output compare value
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__HAL_TIM_SetCompare(&TimMasterHandle, TIM_CHANNEL_1, count);
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// Enable IT
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__HAL_TIM_ENABLE_IT(&TimMasterHandle, TIM_IT_CC1);
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}
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void us_ticker_init(void)
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{
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if (us_ticker_inited) return;
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us_ticker_inited = 1;
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TimMasterHandle.Instance = TIM_MST;
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HAL_InitTick(0); // The passed value is not used
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}
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uint32_t us_ticker_read()
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{
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uint32_t counter;
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TimMasterHandle.Instance = TIM_MST;
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if (!us_ticker_inited) us_ticker_init();
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#if defined(TARGET_STM32L0)
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uint16_t cntH_old, cntH, cntL;
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do {
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// For some reason on L0xx series we need to read and clear the
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// overflow flag which give extra time to propelry handle possible
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// hiccup after ~60s
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if (__HAL_TIM_GET_FLAG(&TimMasterHandle, TIM_FLAG_CC1OF) == SET) {
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__HAL_TIM_CLEAR_FLAG(&TimMasterHandle, TIM_FLAG_CC1OF);
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}
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cntH_old = SlaveCounter;
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if (__HAL_TIM_GET_FLAG(&TimMasterHandle, TIM_FLAG_UPDATE) == SET) {
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cntH_old += 1;
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}
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cntL = TIM_MST->CNT;
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cntH = SlaveCounter;
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if (__HAL_TIM_GET_FLAG(&TimMasterHandle, TIM_FLAG_UPDATE) == SET) {
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cntH += 1;
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}
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} while(cntH_old != cntH);
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// Glue the upper and lower part together to get a 32 bit timer
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return (uint32_t)(cntH << 16 | cntL);
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#else
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tim_it_update = 0; // Clear TIM_IT_UPDATE event flag
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counter = TIM_MST->CNT + (uint32_t)(SlaveCounter << 16); // Calculate new time stamp
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if (tim_it_update == 1) {
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return tim_it_counter; // In case of TIM_IT_UPDATE return the time stamp that was calculated in timer_irq_handler()
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}
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else {
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return counter; // Otherwise return the time stamp calculated here
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}
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#endif
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}
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void us_ticker_set_interrupt(timestamp_t timestamp)
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{
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int delta = (int)((uint32_t)timestamp - us_ticker_read());
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uint16_t cval = TIM_MST->CNT;
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if (delta <= 0) { // This event was in the past
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us_ticker_irq_handler();
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} else {
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oc_int_part = (uint32_t)(delta >> 16);
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oc_rem_part = (uint16_t)(delta & 0xFFFF);
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if (oc_rem_part <= (0xFFFF - cval)) {
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set_compare(cval + oc_rem_part);
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oc_rem_part = 0;
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} else {
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set_compare(0xFFFF);
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oc_rem_part = oc_rem_part - (0xFFFF - cval);
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}
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}
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}
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void us_ticker_disable_interrupt(void)
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{
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TimMasterHandle.Instance = TIM_MST;
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__HAL_TIM_DISABLE_IT(&TimMasterHandle, TIM_IT_CC1);
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}
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void us_ticker_clear_interrupt(void)
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{
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TimMasterHandle.Instance = TIM_MST;
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if (__HAL_TIM_GET_FLAG(&TimMasterHandle, TIM_FLAG_CC1) == SET) {
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__HAL_TIM_CLEAR_FLAG(&TimMasterHandle, TIM_FLAG_CC1);
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}
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}
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#endif // TIM_MST_16BIT
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