xref: /openbmc/u-boot/arch/powerpc/lib/ticks.S (revision f51cdaf1)
1/*
2 * (C) Copyright 2000, 2001
3 * Erik Theisen, Wave 7 Optics, etheisen@mindspring.com.
4 *  base on code by
5 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
6 *
7 * See file CREDITS for list of people who contributed to this
8 * project.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of
13 * the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23 * MA 02111-1307 USA
24 */
25
26#include <ppc_asm.tmpl>
27#include <ppc_defs.h>
28#include <config.h>
29#include <watchdog.h>
30
31/*
32 * unsigned long long get_ticks(void);
33 *
34 * read timebase as "long long"
35 */
36	.globl	get_ticks
37get_ticks:
381:	mftbu	r3
39	mftb	r4
40	mftbu	r5
41	cmp	0,r3,r5
42	bne	1b
43	blr
44
45/*
46 * Delay for a number of ticks
47 */
48	.globl	wait_ticks
49wait_ticks:
50	mflr	r8		/* save link register */
51	mr	r7, r3		/* save tick count */
52	bl	get_ticks	/* Get start time */
53
54	/* Calculate end time */
55	addc    r7, r4, r7	/* Compute end time lower */
56	addze	r6, r3		/*     and end time upper */
57
58	WATCHDOG_RESET		/* Trigger watchdog, if needed */
591:	bl	get_ticks	/* Get current time */
60	subfc	r4, r4, r7	/* Subtract current time from end time */
61	subfe.	r3, r3, r6
62	bge	1b		/* Loop until time expired */
63
64	mtlr	r8		/* restore link register */
65	blr
66