mirror of https://github.com/ARMmbed/mbed-os.git
83 lines
2.2 KiB
C
83 lines
2.2 KiB
C
/* mbed Microcontroller Library
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* Copyright (c) 2006-2018 ARM Limited
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#if DEVICE_USTICKER
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#include "hal/us_ticker_api.h"
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#include "us_ticker_defines.h"
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// This variable is set to 1 at the of mbed_sdk_init function.
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// The ticker_read_us function must not be called until the mbed_sdk_init is terminated.
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extern int mbed_sdk_inited;
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// Defined in us_ticker.c
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void init_16bit_timer(void);
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void init_32bit_timer(void);
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#if TIM_MST_BIT_WIDTH <= 16
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static uint16_t prev_time;
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#else
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static uint32_t prev_time;
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#endif
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static uint32_t total_ticks;
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static uint16_t prev_tick_remainder;
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// Overwrite default HAL functions defined as "weak"
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HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority)
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{
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#if TIM_MST_BIT_WIDTH == 16
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init_16bit_timer();
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#else
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init_32bit_timer();
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#endif
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return HAL_OK;
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}
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uint32_t HAL_GetTick()
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{
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uint32_t new_time = us_ticker_read();
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uint32_t elapsed_time = (((new_time - prev_time) & US_TICKER_MASK) + prev_tick_remainder);
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prev_time = new_time;
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uint32_t elapsed_ticks;
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// Speed optimisation for small time intervals, avoiding a potentially-slow C library divide.
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if (TIM_MST_BIT_WIDTH <= 16 || elapsed_time < 65536) {
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elapsed_ticks = 0;
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while (elapsed_time >= 1000) {
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elapsed_ticks++;
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elapsed_time -= 1000;
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}
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prev_tick_remainder = elapsed_time;
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} else {
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elapsed_ticks = elapsed_time / 1000;
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prev_tick_remainder = elapsed_time % 1000;
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}
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total_ticks += elapsed_ticks;
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return total_ticks;
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}
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void HAL_SuspendTick(void)
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{
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// Do nothing
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}
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void HAL_ResumeTick(void)
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{
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// Do nothing
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}
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#endif /* DEVICE_USTICKER */
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