qmk_firmware/platforms/avr/_wait.h

74 lines
3.2 KiB
C
Raw Blame History

This file contains invisible Unicode characters!

This file contains invisible Unicode characters that may be processed differently from what appears below. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to reveal hidden characters.

/* 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
// Need to disable GCC's "maybe-uninitialized" warning for this file, as it causes issues when running `KEEP_INTERMEDIATES=yes`.
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
#include <util/delay.h>
#pragma GCC diagnostic pop
// 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)