teralytic / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed by teralytic

targets/hal/TARGET_STM/TARGET_STM32L0/us_ticker.c@148:4802eb17e82b, 2016-10-17 (annotated)

Committer:
rodriguise
Date:
Mon Oct 17 18:47:01 2016 +0000
Revision:
148:4802eb17e82b
Parent:
144:ef7eb2e8f9f7 
backup

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2015, STMicroelectronics
<> 144:ef7eb2e8f9f7 3 * All rights reserved.
<> 144:ef7eb2e8f9f7 4 *
<> 144:ef7eb2e8f9f7 5 * Redistribution and use in source and binary forms, with or without
<> 144:ef7eb2e8f9f7 6 * modification, are permitted provided that the following conditions are met:
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * 1. Redistributions of source code must retain the above copyright notice,
<> 144:ef7eb2e8f9f7 9 * this list of conditions and the following disclaimer.
<> 144:ef7eb2e8f9f7 10 * 2. Redistributions in binary form must reproduce the above copyright notice,
<> 144:ef7eb2e8f9f7 11 * this list of conditions and the following disclaimer in the documentation
<> 144:ef7eb2e8f9f7 12 * and/or other materials provided with the distribution.
<> 144:ef7eb2e8f9f7 13 * 3. Neither the name of STMicroelectronics nor the names of its contributors
<> 144:ef7eb2e8f9f7 14 * may be used to endorse or promote products derived from this software
<> 144:ef7eb2e8f9f7 15 * without specific prior written permission.
<> 144:ef7eb2e8f9f7 16 *
<> 144:ef7eb2e8f9f7 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
<> 144:ef7eb2e8f9f7 18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
<> 144:ef7eb2e8f9f7 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
<> 144:ef7eb2e8f9f7 20 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
<> 144:ef7eb2e8f9f7 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
<> 144:ef7eb2e8f9f7 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
<> 144:ef7eb2e8f9f7 23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
<> 144:ef7eb2e8f9f7 24 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
<> 144:ef7eb2e8f9f7 25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
<> 144:ef7eb2e8f9f7 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
<> 144:ef7eb2e8f9f7 27 */
<> 144:ef7eb2e8f9f7 28 #include <stddef.h>
<> 144:ef7eb2e8f9f7 29 #include <stdbool.h>
<> 144:ef7eb2e8f9f7 30 #include "us_ticker_api.h"
<> 144:ef7eb2e8f9f7 31 #include "PeripheralNames.h"
<> 144:ef7eb2e8f9f7 32
<> 144:ef7eb2e8f9f7 33 // Timer selection
<> 144:ef7eb2e8f9f7 34 #define TIM_MST TIM21
<> 144:ef7eb2e8f9f7 35
<> 144:ef7eb2e8f9f7 36 static TIM_HandleTypeDef TimMasterHandle;
<> 144:ef7eb2e8f9f7 37 static int us_ticker_inited = 0;
<> 144:ef7eb2e8f9f7 38
<> 144:ef7eb2e8f9f7 39 volatile uint16_t SlaveCounter = 0;
<> 144:ef7eb2e8f9f7 40 volatile uint32_t oc_int_part = 0;
<> 144:ef7eb2e8f9f7 41 volatile uint16_t oc_rem_part = 0;
<> 144:ef7eb2e8f9f7 42
<> 144:ef7eb2e8f9f7 43 void set_compare(uint16_t count)
<> 144:ef7eb2e8f9f7 44 {
<> 144:ef7eb2e8f9f7 45 TimMasterHandle.Instance = TIM_MST;
<> 144:ef7eb2e8f9f7 46 // Set new output compare value
<> 144:ef7eb2e8f9f7 47 __HAL_TIM_SetCompare(&TimMasterHandle, TIM_CHANNEL_1, count);
<> 144:ef7eb2e8f9f7 48 // Enable IT
<> 144:ef7eb2e8f9f7 49 __HAL_TIM_ENABLE_IT(&TimMasterHandle, TIM_IT_CC1);
<> 144:ef7eb2e8f9f7 50 }
<> 144:ef7eb2e8f9f7 51
<> 144:ef7eb2e8f9f7 52 void us_ticker_init(void)
<> 144:ef7eb2e8f9f7 53 {
<> 144:ef7eb2e8f9f7 54 if (us_ticker_inited) return;
<> 144:ef7eb2e8f9f7 55 us_ticker_inited = 1;
<> 144:ef7eb2e8f9f7 56
<> 144:ef7eb2e8f9f7 57 HAL_InitTick(0); // The passed value is not used
<> 144:ef7eb2e8f9f7 58 }
<> 144:ef7eb2e8f9f7 59
<> 144:ef7eb2e8f9f7 60 uint32_t us_ticker_read()
<> 144:ef7eb2e8f9f7 61 {
<> 144:ef7eb2e8f9f7 62 volatile uint16_t cntH_old, cntH, cntL;
<> 144:ef7eb2e8f9f7 63
<> 144:ef7eb2e8f9f7 64 if (!us_ticker_inited) us_ticker_init();
<> 144:ef7eb2e8f9f7 65
<> 144:ef7eb2e8f9f7 66 do {
<> 144:ef7eb2e8f9f7 67 // For some reason on L0xx series we need to read and clear the
<> 144:ef7eb2e8f9f7 68 // overflow flag which give extra time to propelry handle possible
<> 144:ef7eb2e8f9f7 69 // hiccup after ~60s
<> 144:ef7eb2e8f9f7 70 if (__HAL_TIM_GET_FLAG(&TimMasterHandle, TIM_FLAG_CC1OF) == SET) {
<> 144:ef7eb2e8f9f7 71 __HAL_TIM_CLEAR_FLAG(&TimMasterHandle, TIM_FLAG_CC1OF);
<> 144:ef7eb2e8f9f7 72 }
<> 144:ef7eb2e8f9f7 73 cntH_old = SlaveCounter;
<> 144:ef7eb2e8f9f7 74 if (__HAL_TIM_GET_FLAG(&TimMasterHandle, TIM_FLAG_UPDATE) == SET) {
<> 144:ef7eb2e8f9f7 75 cntH_old += 1;
<> 144:ef7eb2e8f9f7 76 }
<> 144:ef7eb2e8f9f7 77 cntL = TIM_MST->CNT;
<> 144:ef7eb2e8f9f7 78
<> 144:ef7eb2e8f9f7 79 cntH = SlaveCounter;
<> 144:ef7eb2e8f9f7 80 if (__HAL_TIM_GET_FLAG(&TimMasterHandle, TIM_FLAG_UPDATE) == SET) {
<> 144:ef7eb2e8f9f7 81 cntH += 1;
<> 144:ef7eb2e8f9f7 82 }
<> 144:ef7eb2e8f9f7 83 } while(cntH_old != cntH);
<> 144:ef7eb2e8f9f7 84
<> 144:ef7eb2e8f9f7 85 // Glue the upper and lower part together to get a 32 bit timer
<> 144:ef7eb2e8f9f7 86 return (uint32_t)(cntH << 16 | cntL);
<> 144:ef7eb2e8f9f7 87 }
<> 144:ef7eb2e8f9f7 88
<> 144:ef7eb2e8f9f7 89 void us_ticker_set_interrupt(timestamp_t timestamp)
<> 144:ef7eb2e8f9f7 90 {
<> 144:ef7eb2e8f9f7 91 int delta = (int)((uint32_t)timestamp - us_ticker_read());
<> 144:ef7eb2e8f9f7 92 uint16_t cval = TIM_MST->CNT;
<> 144:ef7eb2e8f9f7 93
<> 144:ef7eb2e8f9f7 94 if (delta <= 0) { // This event was in the past
<> 144:ef7eb2e8f9f7 95 us_ticker_irq_handler();
<> 144:ef7eb2e8f9f7 96 } else {
<> 144:ef7eb2e8f9f7 97 oc_int_part = (uint32_t)(delta >> 16);
<> 144:ef7eb2e8f9f7 98 oc_rem_part = (uint16_t)(delta & 0xFFFF);
<> 144:ef7eb2e8f9f7 99 if (oc_rem_part <= (0xFFFF - cval)) {
<> 144:ef7eb2e8f9f7 100 set_compare(cval + oc_rem_part);
<> 144:ef7eb2e8f9f7 101 oc_rem_part = 0;
<> 144:ef7eb2e8f9f7 102 } else {
<> 144:ef7eb2e8f9f7 103 set_compare(0xFFFF);
<> 144:ef7eb2e8f9f7 104 oc_rem_part = oc_rem_part - (0xFFFF - cval);
<> 144:ef7eb2e8f9f7 105 }
<> 144:ef7eb2e8f9f7 106 }
<> 144:ef7eb2e8f9f7 107 }
<> 144:ef7eb2e8f9f7 108
<> 144:ef7eb2e8f9f7 109 void us_ticker_disable_interrupt(void)
<> 144:ef7eb2e8f9f7 110 {
<> 144:ef7eb2e8f9f7 111 TimMasterHandle.Instance = TIM_MST;
<> 144:ef7eb2e8f9f7 112 __HAL_TIM_DISABLE_IT(&TimMasterHandle, TIM_IT_CC1);
<> 144:ef7eb2e8f9f7 113 }
<> 144:ef7eb2e8f9f7 114
<> 144:ef7eb2e8f9f7 115 void us_ticker_clear_interrupt(void)
<> 144:ef7eb2e8f9f7 116 {
<> 144:ef7eb2e8f9f7 117 TimMasterHandle.Instance = TIM_MST;
<> 144:ef7eb2e8f9f7 118 if (__HAL_TIM_GET_FLAG(&TimMasterHandle, TIM_FLAG_CC1) == SET) {
<> 144:ef7eb2e8f9f7 119 __HAL_TIM_CLEAR_FLAG(&TimMasterHandle, TIM_FLAG_CC1);
<> 144:ef7eb2e8f9f7 120 }
<> 144:ef7eb2e8f9f7 121 }