mirror of
https://github.com/smaeul/u-boot.git
synced 2025-11-04 05:50:17 +00:00
80de049561
Use the same way that Linux does for quick TSC calibration via PIT when calibration via MSR fails. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Acked-by: Simon Glass <sjg@chromium.org>
43 lines
1.3 KiB
C
43 lines
1.3 KiB
C
/*
|
|
* (C) Copyright 2002
|
|
* Daniel Engström, Omicron Ceti AB, daniel@omicron.se.
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
|
|
/* i8254.h Intel 8254 PIT registers */
|
|
|
|
|
|
#ifndef _ASMI386_I8254_H_
|
|
#define _ASMI386_I8954_H_ 1
|
|
|
|
|
|
#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 1193182ul
|
|
|
|
#endif
|