Ermanno Brusadin / mbed

mbed library sources

Dependents:   FRDM-KL46Z_LCD_Test FRDM-KL46Z_LCD_Test FRDM-KL46Z_Plantilla FRDM-KL46Z_Plantilla ... more

common/us_ticker_api.c@0:6bc4ac881c8e, 2016-07-28 (annotated)

Committer:
ebrus
Date:
Thu Jul 28 15:56:34 2016 +0000
Revision:
0:6bc4ac881c8e
1;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ebrus 0:6bc4ac881c8e 1 /* mbed Microcontroller Library
ebrus 0:6bc4ac881c8e 2 * Copyright (c) 2006-2013 ARM Limited
ebrus 0:6bc4ac881c8e 3 *
ebrus 0:6bc4ac881c8e 4 * Licensed under the Apache License, Version 2.0 (the "License");
ebrus 0:6bc4ac881c8e 5 * you may not use this file except in compliance with the License.
ebrus 0:6bc4ac881c8e 6 * You may obtain a copy of the License at
ebrus 0:6bc4ac881c8e 7 *
ebrus 0:6bc4ac881c8e 8 * http://www.apache.org/licenses/LICENSE-2.0
ebrus 0:6bc4ac881c8e 9 *
ebrus 0:6bc4ac881c8e 10 * Unless required by applicable law or agreed to in writing, software
ebrus 0:6bc4ac881c8e 11 * distributed under the License is distributed on an "AS IS" BASIS,
ebrus 0:6bc4ac881c8e 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
ebrus 0:6bc4ac881c8e 13 * See the License for the specific language governing permissions and
ebrus 0:6bc4ac881c8e 14 * limitations under the License.
ebrus 0:6bc4ac881c8e 15 */
ebrus 0:6bc4ac881c8e 16 #include <stddef.h>
ebrus 0:6bc4ac881c8e 17 #include "us_ticker_api.h"
ebrus 0:6bc4ac881c8e 18 #include "cmsis.h"
ebrus 0:6bc4ac881c8e 19
ebrus 0:6bc4ac881c8e 20 static ticker_event_handler event_handler;
ebrus 0:6bc4ac881c8e 21 static ticker_event_t *head = NULL;
ebrus 0:6bc4ac881c8e 22
ebrus 0:6bc4ac881c8e 23 void us_ticker_set_handler(ticker_event_handler handler) {
ebrus 0:6bc4ac881c8e 24 us_ticker_init();
ebrus 0:6bc4ac881c8e 25
ebrus 0:6bc4ac881c8e 26 event_handler = handler;
ebrus 0:6bc4ac881c8e 27 }
ebrus 0:6bc4ac881c8e 28
ebrus 0:6bc4ac881c8e 29 void us_ticker_irq_handler(void) {
ebrus 0:6bc4ac881c8e 30 us_ticker_clear_interrupt();
ebrus 0:6bc4ac881c8e 31
ebrus 0:6bc4ac881c8e 32 /* Go through all the pending TimerEvents */
ebrus 0:6bc4ac881c8e 33 while (1) {
ebrus 0:6bc4ac881c8e 34 if (head == NULL) {
ebrus 0:6bc4ac881c8e 35 // There are no more TimerEvents left, so disable matches.
ebrus 0:6bc4ac881c8e 36 us_ticker_disable_interrupt();
ebrus 0:6bc4ac881c8e 37 return;
ebrus 0:6bc4ac881c8e 38 }
ebrus 0:6bc4ac881c8e 39
ebrus 0:6bc4ac881c8e 40 if ((int)(head->timestamp - us_ticker_read()) <= 0) {
ebrus 0:6bc4ac881c8e 41 // This event was in the past:
ebrus 0:6bc4ac881c8e 42 // point to the following one and execute its handler
ebrus 0:6bc4ac881c8e 43 ticker_event_t *p = head;
ebrus 0:6bc4ac881c8e 44 head = head->next;
ebrus 0:6bc4ac881c8e 45 if (event_handler != NULL) {
ebrus 0:6bc4ac881c8e 46 event_handler(p->id); // NOTE: the handler can set new events
ebrus 0:6bc4ac881c8e 47 }
ebrus 0:6bc4ac881c8e 48 /* Note: We continue back to examining the head because calling the
ebrus 0:6bc4ac881c8e 49 * event handler may have altered the chain of pending events. */
ebrus 0:6bc4ac881c8e 50 } else {
ebrus 0:6bc4ac881c8e 51 // This event and the following ones in the list are in the future:
ebrus 0:6bc4ac881c8e 52 // set it as next interrupt and return
ebrus 0:6bc4ac881c8e 53 us_ticker_set_interrupt(head->timestamp);
ebrus 0:6bc4ac881c8e 54 return;
ebrus 0:6bc4ac881c8e 55 }
ebrus 0:6bc4ac881c8e 56 }
ebrus 0:6bc4ac881c8e 57 }
ebrus 0:6bc4ac881c8e 58
ebrus 0:6bc4ac881c8e 59 void us_ticker_insert_event(ticker_event_t *obj, timestamp_t timestamp, uint32_t id) {
ebrus 0:6bc4ac881c8e 60 /* disable interrupts for the duration of the function */
ebrus 0:6bc4ac881c8e 61 __disable_irq();
ebrus 0:6bc4ac881c8e 62
ebrus 0:6bc4ac881c8e 63 // initialise our data
ebrus 0:6bc4ac881c8e 64 obj->timestamp = timestamp;
ebrus 0:6bc4ac881c8e 65 obj->id = id;
ebrus 0:6bc4ac881c8e 66
ebrus 0:6bc4ac881c8e 67 /* Go through the list until we either reach the end, or find
ebrus 0:6bc4ac881c8e 68 an element this should come before (which is possibly the
ebrus 0:6bc4ac881c8e 69 head). */
ebrus 0:6bc4ac881c8e 70 ticker_event_t *prev = NULL, *p = head;
ebrus 0:6bc4ac881c8e 71 while (p != NULL) {
ebrus 0:6bc4ac881c8e 72 /* check if we come before p */
ebrus 0:6bc4ac881c8e 73 if ((int)(timestamp - p->timestamp) <= 0) {
ebrus 0:6bc4ac881c8e 74 break;
ebrus 0:6bc4ac881c8e 75 }
ebrus 0:6bc4ac881c8e 76 /* go to the next element */
ebrus 0:6bc4ac881c8e 77 prev = p;
ebrus 0:6bc4ac881c8e 78 p = p->next;
ebrus 0:6bc4ac881c8e 79 }
ebrus 0:6bc4ac881c8e 80 /* if prev is NULL we're at the head */
ebrus 0:6bc4ac881c8e 81 if (prev == NULL) {
ebrus 0:6bc4ac881c8e 82 head = obj;
ebrus 0:6bc4ac881c8e 83 us_ticker_set_interrupt(timestamp);
ebrus 0:6bc4ac881c8e 84 } else {
ebrus 0:6bc4ac881c8e 85 prev->next = obj;
ebrus 0:6bc4ac881c8e 86 }
ebrus 0:6bc4ac881c8e 87 /* if we're at the end p will be NULL, which is correct */
ebrus 0:6bc4ac881c8e 88 obj->next = p;
ebrus 0:6bc4ac881c8e 89
ebrus 0:6bc4ac881c8e 90 __enable_irq();
ebrus 0:6bc4ac881c8e 91 }
ebrus 0:6bc4ac881c8e 92
ebrus 0:6bc4ac881c8e 93 void us_ticker_remove_event(ticker_event_t *obj) {
ebrus 0:6bc4ac881c8e 94 __disable_irq();
ebrus 0:6bc4ac881c8e 95
ebrus 0:6bc4ac881c8e 96 // remove this object from the list
ebrus 0:6bc4ac881c8e 97 if (head == obj) {
ebrus 0:6bc4ac881c8e 98 // first in the list, so just drop me
ebrus 0:6bc4ac881c8e 99 head = obj->next;
ebrus 0:6bc4ac881c8e 100 if (head == NULL) {
ebrus 0:6bc4ac881c8e 101 us_ticker_disable_interrupt();
ebrus 0:6bc4ac881c8e 102 } else {
ebrus 0:6bc4ac881c8e 103 us_ticker_set_interrupt(head->timestamp);
ebrus 0:6bc4ac881c8e 104 }
ebrus 0:6bc4ac881c8e 105 } else {
ebrus 0:6bc4ac881c8e 106 // find the object before me, then drop me
ebrus 0:6bc4ac881c8e 107 ticker_event_t* p = head;
ebrus 0:6bc4ac881c8e 108 while (p != NULL) {
ebrus 0:6bc4ac881c8e 109 if (p->next == obj) {
ebrus 0:6bc4ac881c8e 110 p->next = obj->next;
ebrus 0:6bc4ac881c8e 111 break;
ebrus 0:6bc4ac881c8e 112 }
ebrus 0:6bc4ac881c8e 113 p = p->next;
ebrus 0:6bc4ac881c8e 114 }
ebrus 0:6bc4ac881c8e 115 }
ebrus 0:6bc4ac881c8e 116
ebrus 0:6bc4ac881c8e 117 __enable_irq();
ebrus 0:6bc4ac881c8e 118 }