mirror of
https://github.com/firewalkwithm3/qmk_firmware.git
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0a1bf7f6aa
* Support using a timer for wait_us() on ChibiOS-based boards (#12198) There are spare GPT timers that can be used to get a more accurate wait_ms() time. This is required for the matrix scan unselect delay (30µs) to be shorter than the system tick rate of 100µs. This is limited to the maximum GPT duration of 65535 so values above that will automatically use the previous implementation based on the system tick. Using a specific timer means it can't be shared by another thread at the same time so when wait_us() is called from anything other than the main thread it will use the system tick implementation too. * Update tmk_core/common/chibios/wait.c * Update tmk_core/common/chibios/wait.c Co-authored-by: Joel Challis <git@zvecr.com>
42 lines
1.3 KiB
C
42 lines
1.3 KiB
C
/* Copyright 2021 QMK
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the 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 program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* 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
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <ch.h>
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#include <hal.h>
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#include "_wait.h"
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#ifdef WAIT_US_TIMER
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void wait_us(uint16_t duration) {
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static const GPTConfig gpt_cfg = {1000000, NULL, 0, 0}; /* 1MHz timer, no callback */
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if (duration == 0) {
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duration = 1;
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}
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/*
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* Only use this timer on the main thread;
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* other threads need to use their own timer.
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*/
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if (chThdGetSelfX() == &ch.mainthread && duration < (1ULL << (sizeof(gptcnt_t) * 8))) {
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gptStart(&WAIT_US_TIMER, &gpt_cfg);
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gptPolledDelay(&WAIT_US_TIMER, duration);
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} else {
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chThdSleepMicroseconds(duration);
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}
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}
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#endif
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