pc_speaker.c

来自「基于组件方式开发操作系统的OSKIT源代码」· C语言 代码 · 共 39 行

/*
 * Copyright (c) 1999 University of Utah and the Flux Group.
 * All rights reserved.
 * 
 * This file is part of the Flux OSKit.  The OSKit is free software, also known
 * as "open source;" you can redistribute it and/or modify it under the terms
 * of the GNU General Public License (GPL), version 2, as published by the Free
 * Software Foundation (FSF).  To explore alternate licensing terms, contact
 * the University of Utah at [e-mail] or [phone].
 * 
 * The OSKit 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 GPL for more details.  You should have
 * received a copy of the GPL along with the OSKit; see the file COPYING.  If
 * not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
 */
/*
 * Control the standard PC speaker.
 */

#include <oskit/x86/pc/speaker.h>
#include <oskit/x86/pc/isa.h>
#include <oskit/x86/pio.h>
#include <oskit/x86/pc/pit.h>
#include <oskit/x86/pc/keyboard.h>

void
pc_speaker_off(void)
{
	outb(IO_PPI, inb_p(IO_PPI) &~ (K_ENABLETMR2|K_SPKRDATA));
}

void
pc_speaker_on(int hz)
{
	outb(IO_PPI, inb_p(IO_PPI) | (K_ENABLETMR2|K_SPKRDATA));
	pit_set(2, PIT_SQWAVE, (PIT_HZ / hz));
}