Fawwaz Nadzmy / mbed-STM

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targets/TARGET_Freescale/TARGET_KSDK2_MCUS/TARGET_KL43Z/us_ticker.c@153:9398a535854b, 2016-12-22 (annotated)

Committer:
fwndz
Date:
Thu Dec 22 05:12:40 2016 +0000
Revision:
153:9398a535854b
Parent:
152:9a67f0b066fc 
device target maximize

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 121:7f86b4238bec 1 /* mbed Microcontroller Library
mbed_official 121:7f86b4238bec 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 121:7f86b4238bec 3 *
mbed_official 121:7f86b4238bec 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 121:7f86b4238bec 5 * you may not use this file except in compliance with the License.
mbed_official 121:7f86b4238bec 6 * You may obtain a copy of the License at
mbed_official 121:7f86b4238bec 7 *
mbed_official 121:7f86b4238bec 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 121:7f86b4238bec 9 *
mbed_official 121:7f86b4238bec 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 121:7f86b4238bec 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 121:7f86b4238bec 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 121:7f86b4238bec 13 * See the License for the specific language governing permissions and
mbed_official 121:7f86b4238bec 14 * limitations under the License.
mbed_official 121:7f86b4238bec 15 */
mbed_official 121:7f86b4238bec 16 #include <stddef.h>
mbed_official 121:7f86b4238bec 17 #include "us_ticker_api.h"
mbed_official 121:7f86b4238bec 18 #include "PeripheralNames.h"
mbed_official 121:7f86b4238bec 19 #include "fsl_pit.h"
mbed_official 121:7f86b4238bec 20 #include "fsl_lptmr.h"
mbed_official 121:7f86b4238bec 21 #include "fsl_clock_config.h"
mbed_official 121:7f86b4238bec 22
mbed_official 121:7f86b4238bec 23 static int us_ticker_inited = 0;
mbed_official 121:7f86b4238bec 24
<> 152:9a67f0b066fc 25 void us_ticker_init(void)
<> 152:9a67f0b066fc 26 {
mbed_official 121:7f86b4238bec 27 if (us_ticker_inited) {
mbed_official 121:7f86b4238bec 28 return;
mbed_official 121:7f86b4238bec 29 }
mbed_official 121:7f86b4238bec 30 us_ticker_inited = 1;
mbed_official 121:7f86b4238bec 31
mbed_official 121:7f86b4238bec 32 //Timer uses PIT
mbed_official 121:7f86b4238bec 33 //Common for ticker/timer
mbed_official 121:7f86b4238bec 34 uint32_t busClock;
mbed_official 121:7f86b4238bec 35
mbed_official 121:7f86b4238bec 36 // Structure to initialize PIT
mbed_official 121:7f86b4238bec 37 pit_config_t pitConfig;
mbed_official 121:7f86b4238bec 38
mbed_official 121:7f86b4238bec 39 PIT_GetDefaultConfig(&pitConfig);
mbed_official 121:7f86b4238bec 40 PIT_Init(PIT, &pitConfig);
mbed_official 121:7f86b4238bec 41
mbed_official 121:7f86b4238bec 42 busClock = CLOCK_GetFreq(kCLOCK_BusClk);
mbed_official 121:7f86b4238bec 43
mbed_official 121:7f86b4238bec 44 PIT_SetTimerPeriod(PIT, kPIT_Chnl_0, busClock / 1000000 - 1);
mbed_official 121:7f86b4238bec 45 PIT_SetTimerPeriod(PIT, kPIT_Chnl_1, 0xFFFFFFFF);
mbed_official 121:7f86b4238bec 46 PIT_SetTimerChainMode(PIT, kPIT_Chnl_1, true);
mbed_official 121:7f86b4238bec 47 PIT_StartTimer(PIT, kPIT_Chnl_0);
mbed_official 121:7f86b4238bec 48 PIT_StartTimer(PIT, kPIT_Chnl_1);
mbed_official 121:7f86b4238bec 49
mbed_official 121:7f86b4238bec 50 //Ticker uses LPTMR
mbed_official 121:7f86b4238bec 51 lptmr_config_t lptmrConfig;
mbed_official 121:7f86b4238bec 52 LPTMR_GetDefaultConfig(&lptmrConfig);
mbed_official 121:7f86b4238bec 53 lptmrConfig.prescalerClockSource = kLPTMR_PrescalerClock_0;
mbed_official 121:7f86b4238bec 54 LPTMR_Init(LPTMR0, &lptmrConfig);
mbed_official 121:7f86b4238bec 55
mbed_official 121:7f86b4238bec 56 busClock = CLOCK_GetFreq(kCLOCK_McgInternalRefClk);
mbed_official 121:7f86b4238bec 57 LPTMR_SetTimerPeriod(LPTMR0, busClock / 1000000 - 1);
mbed_official 121:7f86b4238bec 58 /* Set interrupt handler */
mbed_official 121:7f86b4238bec 59 NVIC_SetVector(LPTMR0_IRQn, (uint32_t)us_ticker_irq_handler);
mbed_official 121:7f86b4238bec 60 NVIC_EnableIRQ(LPTMR0_IRQn);
mbed_official 121:7f86b4238bec 61 }
mbed_official 121:7f86b4238bec 62
mbed_official 121:7f86b4238bec 63
<> 152:9a67f0b066fc 64 uint32_t us_ticker_read()
<> 152:9a67f0b066fc 65 {
mbed_official 121:7f86b4238bec 66 if (!us_ticker_inited) {
mbed_official 121:7f86b4238bec 67 us_ticker_init();
mbed_official 121:7f86b4238bec 68 }
mbed_official 121:7f86b4238bec 69
mbed_official 121:7f86b4238bec 70 return ~(PIT_GetCurrentTimerCount(PIT, kPIT_Chnl_1));
mbed_official 121:7f86b4238bec 71 }
mbed_official 121:7f86b4238bec 72
<> 152:9a67f0b066fc 73 void us_ticker_disable_interrupt(void)
<> 152:9a67f0b066fc 74 {
mbed_official 121:7f86b4238bec 75 LPTMR_DisableInterrupts(LPTMR0, kLPTMR_TimerInterruptEnable);
mbed_official 121:7f86b4238bec 76 }
mbed_official 121:7f86b4238bec 77
<> 152:9a67f0b066fc 78 void us_ticker_clear_interrupt(void)
<> 152:9a67f0b066fc 79 {
mbed_official 121:7f86b4238bec 80 LPTMR_ClearStatusFlags(LPTMR0, kLPTMR_TimerCompareFlag);
mbed_official 121:7f86b4238bec 81 }
mbed_official 121:7f86b4238bec 82
<> 152:9a67f0b066fc 83 void us_ticker_set_interrupt(timestamp_t timestamp)
<> 152:9a67f0b066fc 84 {
mbed_official 121:7f86b4238bec 85 int delta = (int)(timestamp - us_ticker_read());
mbed_official 121:7f86b4238bec 86 if (delta <= 0) {
mbed_official 121:7f86b4238bec 87 // This event was in the past.
mbed_official 121:7f86b4238bec 88 // Set the interrupt as pending, but don't process it here.
mbed_official 121:7f86b4238bec 89 // This prevents a recurive loop under heavy load
mbed_official 121:7f86b4238bec 90 // which can lead to a stack overflow.
mbed_official 121:7f86b4238bec 91 NVIC_SetPendingIRQ(LPTMR0_IRQn);
mbed_official 121:7f86b4238bec 92 return;
mbed_official 121:7f86b4238bec 93 }
mbed_official 121:7f86b4238bec 94
mbed_official 121:7f86b4238bec 95 LPTMR_StopTimer(LPTMR0);
mbed_official 121:7f86b4238bec 96 LPTMR_SetTimerPeriod(LPTMR0, (uint32_t)delta);
mbed_official 121:7f86b4238bec 97 LPTMR_EnableInterrupts(LPTMR0, kLPTMR_TimerInterruptEnable);
mbed_official 121:7f86b4238bec 98 LPTMR_StartTimer(LPTMR0);
mbed_official 121:7f86b4238bec 99 }