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47 lines
1.4 KiB
47 lines
1.4 KiB
/* |
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* Copyright (C) Siddharth Bharat Purohit 2017 |
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* This file is free software: you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License as published by the |
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* Free Software Foundation, either version 3 of the License, or |
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* (at your option) any later version. |
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* |
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* This file is distributed in the hope that it will be useful, but |
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* WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
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* See the GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License along |
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* with this program. If not, see <http://www.gnu.org/licenses/>. |
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*/ |
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// High Resolution Timer |
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#include "ch.h" |
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#include "hal.h" |
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#include "hrt.h" |
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#include <stdint.h> |
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static uint64_t timer_base = 0; |
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uint64_t hrt_micros() |
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{ |
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static volatile uint64_t last_micros; |
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/* |
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use chSysGetStatusAndLockX() to prevent an interrupt while |
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allowing this call from any context |
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*/ |
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syssts_t sts = chSysGetStatusAndLockX(); |
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uint64_t micros; |
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micros = timer_base + (uint64_t)chVTGetSystemTimeX(); |
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// we are doing this to avoid an additional interupt routing |
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// since we are definitely going to get called atleast once in |
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// a full timer period |
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if (last_micros > micros) { |
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const uint64_t step = ST2US(1ULL<<CH_CFG_ST_RESOLUTION); |
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timer_base += step; |
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micros += step; |
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} |
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last_micros = micros; |
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chSysRestoreStatusX(sts); |
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return micros; |
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}
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