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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, daniel@omicron.se.
*/
/* i8254.h Intel 8254 PIT registers */
#ifndef _ASMI386_I8254_H_
#define _ASMI386_I8954_H_
#define PIT_T0 0x00 /* PIT channel 0 count/status */
#define PIT_T1 0x01 /* PIT channel 1 count/status */
#define PIT_T2 0x02 /* PIT channel 2 count/status */
#define PIT_COMMAND 0x03 /* PIT mode control, latch and read back */
/* PIT Command Register Bit Definitions */
#define PIT_CMD_CTR0 0x00 /* Select PIT counter 0 */
#define PIT_CMD_CTR1 0x40 /* Select PIT counter 1 */
#define PIT_CMD_CTR2 0x80 /* Select PIT counter 2 */
#define PIT_CMD_LATCH 0x00 /* Counter Latch Command */
#define PIT_CMD_LOW 0x10 /* Access counter bits 7-0 */
#define PIT_CMD_HIGH 0x20 /* Access counter bits 15-8 */
#define PIT_CMD_BOTH 0x30 /* Access counter bits 15-0 in two accesses */
#define PIT_CMD_MODE0 0x00 /* Select mode 0 */
#define PIT_CMD_MODE1 0x02 /* Select mode 1 */
#define PIT_CMD_MODE2 0x04 /* Select mode 2 */
#define PIT_CMD_MODE3 0x06 /* Select mode 3 */
#define PIT_CMD_MODE4 0x08 /* Select mode 4 */
#define PIT_CMD_MODE5 0x0a /* Select mode 5 */
/* The clock frequency of the i8253/i8254 PIT */
#define PIT_TICK_RATE 1193182
/**
* i8254_enable_beep() - Start a beep using the PCAT timer
*
* This starts beeping using the legacy i8254 timer. The beep may be silenced
* after a delay with i8254_disable_beep().
*
* @frequency_hz: Frequency of beep in Hz
* @return 0 if OK, -EINVAL if frequency_hz is 0
*/
int i8254_enable_beep(uint frequency_hz);
/**
* i8254_disable_beep() - Disable the bepper
*
* This stops any existing beep
*/
void i8254_disable_beep(void);
#endif /* _ASMI386_I8954_H_ */
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