Yihui Xiong / BLE_NODE_TEST

Test code for Grove Node BLE

Dependencies:   BLE_API nRF51822

Fork of BLE_LoopbackUART by Bluetooth Low Energy

mbed-src/targets/hal/TARGET_NORDIC/TARGET_MCU_NRF51822/us_ticker.c@10:22480ac31879, 2014-11-27 (annotated)

Committer:
yihui
Date:
Thu Nov 27 09:30:36 2014 +0000
Revision:
10:22480ac31879
Parent:
9:05f0b5a3a70a 
change to new revision hardware

Who changed what in which revision?

UserRevisionLine numberNew contents of line
yihui 9:05f0b5a3a70a 1 /* mbed Microcontroller Library
yihui 9:05f0b5a3a70a 2 * Copyright (c) 2013 Nordic Semiconductor
yihui 9:05f0b5a3a70a 3 *
yihui 9:05f0b5a3a70a 4 * Licensed under the Apache License, Version 2.0 (the "License");
yihui 9:05f0b5a3a70a 5 * you may not use this file except in compliance with the License.
yihui 9:05f0b5a3a70a 6 * You may obtain a copy of the License at
yihui 9:05f0b5a3a70a 7 *
yihui 9:05f0b5a3a70a 8 * http://www.apache.org/licenses/LICENSE-2.0
yihui 9:05f0b5a3a70a 9 *
yihui 9:05f0b5a3a70a 10 * Unless required by applicable law or agreed to in writing, software
yihui 9:05f0b5a3a70a 11 * distributed under the License is distributed on an "AS IS" BASIS,
yihui 9:05f0b5a3a70a 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
yihui 9:05f0b5a3a70a 13 * See the License for the specific language governing permissions and
yihui 9:05f0b5a3a70a 14 * limitations under the License.
yihui 9:05f0b5a3a70a 15 */
yihui 9:05f0b5a3a70a 16 #include <stddef.h>
yihui 9:05f0b5a3a70a 17 #include "us_ticker_api.h"
yihui 9:05f0b5a3a70a 18 #include "cmsis.h"
yihui 9:05f0b5a3a70a 19 #include "PeripheralNames.h"
yihui 9:05f0b5a3a70a 20 #include "app_timer.h"
yihui 9:05f0b5a3a70a 21
yihui 9:05f0b5a3a70a 22 static bool us_ticker_inited = false;
yihui 9:05f0b5a3a70a 23 static volatile bool us_ticker_appTimerRunning = false;
yihui 9:05f0b5a3a70a 24 static app_timer_id_t us_ticker_appTimerID = TIMER_NULL;
yihui 9:05f0b5a3a70a 25
yihui 9:05f0b5a3a70a 26 void us_ticker_init(void)
yihui 9:05f0b5a3a70a 27 {
yihui 9:05f0b5a3a70a 28 if (us_ticker_inited) {
yihui 9:05f0b5a3a70a 29 return;
yihui 9:05f0b5a3a70a 30 }
yihui 9:05f0b5a3a70a 31
yihui 9:05f0b5a3a70a 32 APP_TIMER_INIT(0 /*CFG_TIMER_PRESCALER*/ , 1 /*CFG_TIMER_MAX_INSTANCE*/, 1 /*CFG_TIMER_OPERATION_QUEUE_SIZE*/, false /*CFG_SCHEDULER_ENABLE*/);
yihui 9:05f0b5a3a70a 33
yihui 9:05f0b5a3a70a 34 us_ticker_inited = true;
yihui 9:05f0b5a3a70a 35 }
yihui 9:05f0b5a3a70a 36
yihui 9:05f0b5a3a70a 37 uint32_t us_ticker_read()
yihui 9:05f0b5a3a70a 38 {
yihui 9:05f0b5a3a70a 39 if (!us_ticker_inited) {
yihui 9:05f0b5a3a70a 40 us_ticker_init();
yihui 9:05f0b5a3a70a 41 }
yihui 9:05f0b5a3a70a 42
yihui 9:05f0b5a3a70a 43 timestamp_t value;
yihui 9:05f0b5a3a70a 44 app_timer_cnt_get(&value); /* This returns the RTC counter (which is fed by the 32khz crystal clock source) */
yihui 9:05f0b5a3a70a 45 return ((value * 1000000) / (uint32_t)APP_TIMER_CLOCK_FREQ); /* Return a pseudo microsecond counter value.
yihui 9:05f0b5a3a70a 46 * This is only as precise as the 32khz low-freq
yihui 9:05f0b5a3a70a 47 * clock source, but could be adequate.*/
yihui 9:05f0b5a3a70a 48 }
yihui 9:05f0b5a3a70a 49
yihui 9:05f0b5a3a70a 50 /* An adaptor to interface us_ticker_irq_handler with the app_timer callback.
yihui 9:05f0b5a3a70a 51 * Needed because the irq_handler() doesn't take any parameter.*/
yihui 9:05f0b5a3a70a 52 static void us_ticker_app_timer_callback(void *context)
yihui 9:05f0b5a3a70a 53 {
yihui 9:05f0b5a3a70a 54 us_ticker_appTimerRunning = false;
yihui 9:05f0b5a3a70a 55 us_ticker_irq_handler();
yihui 9:05f0b5a3a70a 56 }
yihui 9:05f0b5a3a70a 57
yihui 9:05f0b5a3a70a 58 void us_ticker_set_interrupt(timestamp_t timestamp)
yihui 9:05f0b5a3a70a 59 {
yihui 9:05f0b5a3a70a 60 if (!us_ticker_inited) {
yihui 9:05f0b5a3a70a 61 us_ticker_init();
yihui 9:05f0b5a3a70a 62 }
yihui 9:05f0b5a3a70a 63
yihui 9:05f0b5a3a70a 64 if (us_ticker_appTimerID == TIMER_NULL) {
yihui 9:05f0b5a3a70a 65 if (app_timer_create(&us_ticker_appTimerID, APP_TIMER_MODE_SINGLE_SHOT, us_ticker_app_timer_callback) != NRF_SUCCESS) {
yihui 9:05f0b5a3a70a 66 /* placeholder to do something to recover from error */
yihui 9:05f0b5a3a70a 67 return;
yihui 9:05f0b5a3a70a 68 }
yihui 9:05f0b5a3a70a 69 }
yihui 9:05f0b5a3a70a 70
yihui 9:05f0b5a3a70a 71 if (us_ticker_appTimerRunning) {
yihui 9:05f0b5a3a70a 72 return;
yihui 9:05f0b5a3a70a 73 }
yihui 9:05f0b5a3a70a 74
yihui 9:05f0b5a3a70a 75 timestamp_t currentCounter64;
yihui 9:05f0b5a3a70a 76 app_timer_cnt_get(&currentCounter64);
yihui 9:05f0b5a3a70a 77 uint32_t currentCounter = currentCounter64 & MAX_RTC_COUNTER_VAL;
yihui 9:05f0b5a3a70a 78 uint32_t targetCounter = ((uint32_t)((timestamp * (uint64_t)APP_TIMER_CLOCK_FREQ) / 1000000) + 1) & MAX_RTC_COUNTER_VAL;
yihui 9:05f0b5a3a70a 79 uint32_t ticksToCount = (targetCounter >= currentCounter) ?
yihui 9:05f0b5a3a70a 80 (targetCounter - currentCounter) : (MAX_RTC_COUNTER_VAL + 1) - (currentCounter - targetCounter);
yihui 9:05f0b5a3a70a 81 if (ticksToCount < APP_TIMER_MIN_TIMEOUT_TICKS) { /* Honour the minimum value of the timeout_ticks parameter of app_timer_start() */
yihui 9:05f0b5a3a70a 82 ticksToCount = APP_TIMER_MIN_TIMEOUT_TICKS;
yihui 9:05f0b5a3a70a 83 }
yihui 9:05f0b5a3a70a 84
yihui 9:05f0b5a3a70a 85 uint32_t rc;
yihui 9:05f0b5a3a70a 86 rc = app_timer_start(us_ticker_appTimerID, ticksToCount, NULL /*p_context*/);
yihui 9:05f0b5a3a70a 87 if (rc != NRF_SUCCESS) {
yihui 9:05f0b5a3a70a 88 /* placeholder to do something to recover from error */
yihui 9:05f0b5a3a70a 89 return;
yihui 9:05f0b5a3a70a 90 }
yihui 9:05f0b5a3a70a 91 us_ticker_appTimerRunning = true;
yihui 9:05f0b5a3a70a 92 }
yihui 9:05f0b5a3a70a 93
yihui 9:05f0b5a3a70a 94 void us_ticker_disable_interrupt(void)
yihui 9:05f0b5a3a70a 95 {
yihui 9:05f0b5a3a70a 96 if (us_ticker_appTimerRunning) {
yihui 9:05f0b5a3a70a 97 app_timer_stop(us_ticker_appTimerID);
yihui 9:05f0b5a3a70a 98 }
yihui 9:05f0b5a3a70a 99 }
yihui 9:05f0b5a3a70a 100
yihui 9:05f0b5a3a70a 101 void us_ticker_clear_interrupt(void)
yihui 9:05f0b5a3a70a 102 {
yihui 9:05f0b5a3a70a 103 if (us_ticker_appTimerRunning) {
yihui 9:05f0b5a3a70a 104 app_timer_stop(us_ticker_appTimerID);
yihui 9:05f0b5a3a70a 105 }
yihui 9:05f0b5a3a70a 106 }