/* mbed Microcontroller Library * Copyright (c) 2018 ARM Limited * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #if DEVICE_LPTICKER #include "lp_ticker_api.h" #include "fsl_gpt.h" #include "cmsis.h" const ticker_info_t* lp_ticker_get_info() { static const ticker_info_t info = { 32768, // 32kHz 32 // 32 bit counter }; return &info; } static bool lp_ticker_inited = false; static void gpt_isr(void) { GPT_ClearStatusFlags(GPT2, kGPT_OutputCompare1Flag); GPT_DisableInterrupts(GPT2, kGPT_OutputCompare1InterruptEnable); lp_ticker_irq_handler(); } /** Initialize the low power ticker * */ void lp_ticker_init(void) { gpt_config_t gptConfig; if (!lp_ticker_inited) { /* Setup GPT */ GPT_GetDefaultConfig(&gptConfig); /* Use 32kHz drive */ gptConfig.clockSource = kGPT_ClockSource_LowFreq; gptConfig.enableFreeRun = true; gptConfig.enableMode = false; gptConfig.enableRunInDoze = true; GPT_Init(GPT2, &gptConfig); GPT_EnableInterrupts(GPT2, kGPT_OutputCompare1InterruptEnable); NVIC_ClearPendingIRQ(GPT2_IRQn); NVIC_SetVector(GPT2_IRQn, (uint32_t)gpt_isr); EnableIRQ(GPT2_IRQn); GPT_StartTimer(GPT2); lp_ticker_inited = true; } else { GPT_DisableInterrupts(GPT2, kGPT_OutputCompare1InterruptEnable); } } /** Read the current counter * * @return The current timer's counter value in ticks */ uint32_t lp_ticker_read(void) { return GPT_GetCurrentTimerCount(GPT2); } /** Set interrupt for specified timestamp * * @param timestamp The time in ticks to be set */ void lp_ticker_set_interrupt(timestamp_t timestamp) { if (timestamp == 0) { timestamp = 1; } GPT_StopTimer(GPT2); GPT_SetOutputCompareValue(GPT2, kGPT_OutputCompare_Channel1, timestamp); GPT_ClearStatusFlags(GPT2, kGPT_OutputCompare1Flag); GPT_EnableInterrupts(GPT2, kGPT_OutputCompare1InterruptEnable); GPT_StartTimer(GPT2); } void lp_ticker_fire_interrupt(void) { NVIC_SetPendingIRQ(GPT2_IRQn); } /** Disable low power ticker interrupt * */ void lp_ticker_disable_interrupt(void) { GPT_DisableInterrupts(GPT2, kGPT_OutputCompare1InterruptEnable); } /** Clear the low power ticker interrupt * */ void lp_ticker_clear_interrupt(void) { GPT_ClearStatusFlags(GPT2, kGPT_OutputCompare1Flag); } void lp_ticker_free(void) { GPT_DisableInterrupts(GPT2, kGPT_OutputCompare1InterruptEnable); NVIC_DisableIRQ(GPT2_IRQn); } #endif /* DEVICE_LPTICKER */