Lee Kai Xuan / mbed-os

mbed-os

Fork of mbed-os by erkin yucel

targets/TARGET_STM/TARGET_STM32F1/us_ticker.c@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

Who changed what in which revision?

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elessair 0:f269e3021894 1 /* mbed Microcontroller Library
elessair 0:f269e3021894 2 * Copyright (c) 2014, STMicroelectronics
elessair 0:f269e3021894 3 * All rights reserved.
elessair 0:f269e3021894 4 *
elessair 0:f269e3021894 5 * Redistribution and use in source and binary forms, with or without
elessair 0:f269e3021894 6 * modification, are permitted provided that the following conditions are met:
elessair 0:f269e3021894 7 *
elessair 0:f269e3021894 8 * 1. Redistributions of source code must retain the above copyright notice,
elessair 0:f269e3021894 9 * this list of conditions and the following disclaimer.
elessair 0:f269e3021894 10 * 2. Redistributions in binary form must reproduce the above copyright notice,
elessair 0:f269e3021894 11 * this list of conditions and the following disclaimer in the documentation
elessair 0:f269e3021894 12 * and/or other materials provided with the distribution.
elessair 0:f269e3021894 13 * 3. Neither the name of STMicroelectronics nor the names of its contributors
elessair 0:f269e3021894 14 * may be used to endorse or promote products derived from this software
elessair 0:f269e3021894 15 * without specific prior written permission.
elessair 0:f269e3021894 16 *
elessair 0:f269e3021894 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
elessair 0:f269e3021894 18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
elessair 0:f269e3021894 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
elessair 0:f269e3021894 20 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
elessair 0:f269e3021894 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
elessair 0:f269e3021894 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
elessair 0:f269e3021894 23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
elessair 0:f269e3021894 24 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
elessair 0:f269e3021894 25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
elessair 0:f269e3021894 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
elessair 0:f269e3021894 27 */
elessair 0:f269e3021894 28 #include <stddef.h>
elessair 0:f269e3021894 29 #include "us_ticker_api.h"
elessair 0:f269e3021894 30 #include "PeripheralNames.h"
elessair 0:f269e3021894 31
elessair 0:f269e3021894 32 // Timer selection
elessair 0:f269e3021894 33 #define TIM_MST TIM4
elessair 0:f269e3021894 34
elessair 0:f269e3021894 35 static TIM_HandleTypeDef TimMasterHandle;
elessair 0:f269e3021894 36 static int us_ticker_inited = 0;
elessair 0:f269e3021894 37
elessair 0:f269e3021894 38 volatile uint32_t SlaveCounter = 0;
elessair 0:f269e3021894 39 volatile uint32_t oc_int_part = 0;
elessair 0:f269e3021894 40 volatile uint16_t oc_rem_part = 0;
elessair 0:f269e3021894 41 volatile uint16_t cnt_val = 0;
elessair 0:f269e3021894 42
elessair 0:f269e3021894 43 void set_compare(uint16_t count)
elessair 0:f269e3021894 44 {
elessair 0:f269e3021894 45 TimMasterHandle.Instance = TIM_MST;
elessair 0:f269e3021894 46 // Set new output compare value
elessair 0:f269e3021894 47 __HAL_TIM_SetCompare(&TimMasterHandle, TIM_CHANNEL_1, count);
elessair 0:f269e3021894 48 // Enable IT
elessair 0:f269e3021894 49 __HAL_TIM_ENABLE_IT(&TimMasterHandle, TIM_IT_CC1);
elessair 0:f269e3021894 50 }
elessair 0:f269e3021894 51
elessair 0:f269e3021894 52 void us_ticker_init(void)
elessair 0:f269e3021894 53 {
elessair 0:f269e3021894 54 if (us_ticker_inited) return;
elessair 0:f269e3021894 55 us_ticker_inited = 1;
elessair 0:f269e3021894 56
elessair 0:f269e3021894 57 HAL_InitTick(0); // The passed value is not used
elessair 0:f269e3021894 58 }
elessair 0:f269e3021894 59
elessair 0:f269e3021894 60 uint32_t us_ticker_read()
elessair 0:f269e3021894 61 {
elessair 0:f269e3021894 62 uint32_t counter;
elessair 0:f269e3021894 63 if (!us_ticker_inited) us_ticker_init();
elessair 0:f269e3021894 64
elessair 0:f269e3021894 65 //Current value of TIM_MST->CNT is stored in cnt_val and is
elessair 0:f269e3021894 66 //updated in interrupt context
elessair 0:f269e3021894 67 counter = (uint32_t)(SlaveCounter << 16);
elessair 0:f269e3021894 68 counter += cnt_val;
elessair 0:f269e3021894 69
elessair 0:f269e3021894 70 return counter;
elessair 0:f269e3021894 71 }
elessair 0:f269e3021894 72
elessair 0:f269e3021894 73 void us_ticker_set_interrupt(timestamp_t timestamp)
elessair 0:f269e3021894 74 {
elessair 0:f269e3021894 75 int delta = (int)((uint32_t)timestamp - us_ticker_read());
elessair 0:f269e3021894 76 uint16_t cval = TIM_MST->CNT;
elessair 0:f269e3021894 77
elessair 0:f269e3021894 78 if (delta <= 0) { // This event was in the past
elessair 0:f269e3021894 79 us_ticker_irq_handler();
elessair 0:f269e3021894 80 } else {
elessair 0:f269e3021894 81 oc_int_part = (uint32_t)(delta >> 16);
elessair 0:f269e3021894 82 oc_rem_part = (uint16_t)(delta & 0xFFFF);
elessair 0:f269e3021894 83 if (oc_rem_part <= (0xFFFF - cval)) {
elessair 0:f269e3021894 84 set_compare(cval + oc_rem_part);
elessair 0:f269e3021894 85 oc_rem_part = 0;
elessair 0:f269e3021894 86 } else {
elessair 0:f269e3021894 87 set_compare(0xFFFF);
elessair 0:f269e3021894 88 oc_rem_part = oc_rem_part - (0xFFFF - cval);
elessair 0:f269e3021894 89 }
elessair 0:f269e3021894 90 }
elessair 0:f269e3021894 91 }
elessair 0:f269e3021894 92
elessair 0:f269e3021894 93 void us_ticker_disable_interrupt(void)
elessair 0:f269e3021894 94 {
elessair 0:f269e3021894 95 TimMasterHandle.Instance = TIM_MST;
elessair 0:f269e3021894 96 __HAL_TIM_DISABLE_IT(&TimMasterHandle, TIM_IT_CC1);
elessair 0:f269e3021894 97 }
elessair 0:f269e3021894 98
elessair 0:f269e3021894 99 void us_ticker_clear_interrupt(void)
elessair 0:f269e3021894 100 {
elessair 0:f269e3021894 101 TimMasterHandle.Instance = TIM_MST;
elessair 0:f269e3021894 102 if (__HAL_TIM_GET_FLAG(&TimMasterHandle, TIM_FLAG_CC1) == SET) {
elessair 0:f269e3021894 103 __HAL_TIM_CLEAR_FLAG(&TimMasterHandle, TIM_FLAG_CC1);
elessair 0:f269e3021894 104 }
elessair 0:f269e3021894 105 }