delay_impl.hpp.in

/*
 * Copyright (c) 2020, Niklas Hauser
 *
 * This file is part of the modm project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
// ----------------------------------------------------------------------------

#pragma once

/// @cond
#include <util/delay.h>
#include <modm/architecture/utils.hpp>

#define MODM_DELAY_NS_IS_ACCURATE 0

namespace modm
{

modm_always_inline void
delay_ns(uint32_t ns)
{
	__builtin_constant_p(ns) ? ({
		// ns is a constant value, we can let the compiler do the work
		const uint32_t cycles = uint32_t(ceil(fabs((F_CPU * double(ns)) / 1e9)));
		__builtin_avr_delay_cycles(cycles);
	}) : ({
		const uint16_t loops = ns >> {{ shift }};
		if (loops) _delay_loop_2(loops);
	});
}
modm_always_inline void
delay_us(uint32_t us)
{
	__builtin_constant_p(us) ? ({
		// ns is a constant value, we can let the compiler do the work
		const uint32_t cycles = uint32_t(ceil(fabs((F_CPU * double(us)) / 1e6)));
		__builtin_avr_delay_cycles(cycles);
	}) : ({
%% if f_cpu <= 6000000
		constexpr int32_t cycles = (F_CPU / 1e6);
		for (int32_t _us = us; _us > 0; _us -= cycles)
			__builtin_avr_delay_cycles(1);
%% else
		constexpr int32_t cycles = (F_CPU / 1e6) - 6;
		for (uint32_t _us = us; _us; _us--)
			__builtin_avr_delay_cycles(cycles);
%% endif
	});
}
modm_always_inline void
delay_ms(uint32_t ms)
{
	__builtin_constant_p(ms) ? ({
		// ns is a constant value, we can let the compiler do the work
		const uint32_t cycles = uint32_t(ceil(fabs((F_CPU * double(ms)) / 1e3)));
		__builtin_avr_delay_cycles(cycles);
	}) : ({
		while(ms--) __builtin_avr_delay_cycles((F_CPU / 1e3) - 10);
	});
}

}   // namespace modm
/// @endcond