diff options
Diffstat (limited to 'roms/u-boot/arch/x86/include/asm/i8254.h')
| -rw-r--r-- | roms/u-boot/arch/x86/include/asm/i8254.h | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/roms/u-boot/arch/x86/include/asm/i8254.h b/roms/u-boot/arch/x86/include/asm/i8254.h new file mode 100644 index 000000000..d769daf85 --- /dev/null +++ b/roms/u-boot/arch/x86/include/asm/i8254.h @@ -0,0 +1,56 @@ +/* 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_ */ |