3 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
5 * SPDX-License-Identifier: GPL-2.0+
10 #include <asm/i8254.h>
12 #define TIMER2_VALUE 0x0a8e /* 440Hz */
14 int pcat_timer_init(void)
17 * Initialize counter 2, used to drive the speaker.
18 * To start a beep, set both bit0 and bit1 of port 0x61.
19 * To stop it, clear both bit0 and bit1 of port 0x61.
21 outb(PIT_CMD_CTR2 | PIT_CMD_BOTH | PIT_CMD_MODE3,
22 PIT_BASE + PIT_COMMAND);
23 outb(TIMER2_VALUE & 0xff, PIT_BASE + PIT_T2);
24 outb(TIMER2_VALUE >> 8, PIT_BASE + PIT_T2);