ladybird/Kernel/Devices/PCSpeaker.cpp
Hendiadyoin1 62f9377656 Kernel: Move special sections into Sections.h
This also removes a lot of CPU.h includes infavor for Sections.h
2021-06-24 00:38:23 +02:00

25 lines
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C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Devices/PCSpeaker.h>
#include <Kernel/IO.h>
#include <Kernel/Time/PIT.h>
void PCSpeaker::tone_on(int frequency)
{
IO::out8(PIT_CTL, TIMER2_SELECT | WRITE_WORD | MODE_SQUARE_WAVE);
u16 timer_reload = BASE_FREQUENCY / frequency;
IO::out8(TIMER2_CTL, LSB(timer_reload));
IO::out8(TIMER2_CTL, MSB(timer_reload));
IO::out8(0x61, IO::in8(0x61) | 3);
}
void PCSpeaker::tone_off()
{
IO::out8(0x61, IO::in8(0x61) & ~3);
}