qmk_firmware/platforms/avr/_wait.h

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/* Copyright 2021 QMK
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <util/delay.h>
// http://ww1.microchip.com/downloads/en/devicedoc/atmel-0856-avr-instruction-set-manual.pdf
// page 22: Table 4-2.Arithmetic and Logic Instructions
/*
for (uint16_t i = times; i > 0; i--) {
__builtin_avr_delay_cycles(1);
}
.L3: sbiw r24,0 // loop step 1
brne .L4 // loop step 2
ret
.L4: nop // __builtin_avr_delay_cycles(1);
sbiw r24,1 // loop step 3
rjmp .L3 // loop step 4
*/
#define AVR_sbiw_clocks 2
#define AVR_rjmp_clocks 2
#define AVR_brne_clocks 2
#define AVR_WAIT_LOOP_OVERHEAD (AVR_sbiw_clocks + AVR_brne_clocks + AVR_sbiw_clocks + AVR_rjmp_clocks)
#define wait_ms(ms) \
do { \
if (__builtin_constant_p(ms)) { \
_delay_ms(ms); \
} else { \
for (uint16_t i = ms; i > 0; i--) { \
_delay_ms(1); \
} \
} \
} while (0)
#define wait_us(us) \
do { \
if (__builtin_constant_p(us)) { \
_delay_us(us); \
} else { \
for (uint16_t i = us; i > 0; i--) { \
__builtin_avr_delay_cycles((F_CPU / 1000000) - AVR_WAIT_LOOP_OVERHEAD); \
} \
} \
} while (0)
#define wait_cpuclock(n) __builtin_avr_delay_cycles(n)
#define CPU_CLOCK F_CPU
/* The AVR series GPIOs have a one clock read delay for changes in the digital input signal.
* But here's more margin to make it two clocks. */
#ifndef GPIO_INPUT_PIN_DELAY
# define GPIO_INPUT_PIN_DELAY 2
#endif
#define waitInputPinDelay() wait_cpuclock(GPIO_INPUT_PIN_DELAY)