u-boot/arch/x86/lib/pcat_timer.c
Simon Glass d0b6f247a1 x86: Re-enable PCAT timer 2 for beeping
While we don't want PCAT timers for timing, we want timer 2 so that we can
still make a beep. Re-purpose the PCAT driver for this, and enable it in
coreboot.

Signed-off-by: Simon Glass <sjg@chromium.org>
2013-05-13 13:33:21 -07:00

43 lines
1.3 KiB
C

/*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <asm/io.h>
#include <asm/i8254.h>
#define TIMER2_VALUE 0x0a8e /* 440Hz */
int pcat_timer_init(void)
{
/*
* initialize 2, used to drive the speaker
* (to start a beep: write 3 to port 0x61,
* to stop it again: write 0)
*/
outb(PIT_CMD_CTR2 | PIT_CMD_BOTH | PIT_CMD_MODE3,
PIT_BASE + PIT_COMMAND);
outb(TIMER2_VALUE & 0xff, PIT_BASE + PIT_T2);
outb(TIMER2_VALUE >> 8, PIT_BASE + PIT_T2);
return 0;
}