mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-12 22:33:18 +00:00
79a5be820d
Adjust the code to allow beeping at different frequencies, using a calculated value for timer 2. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
56 lines
1.7 KiB
C
56 lines
1.7 KiB
C
/* 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_ */
|