xref: /netbsd-src/sys/arch/mmeye/stand/boot/clock.c (revision 1caa7e3dc2a9f2b3891966cb13d9a7452957a51a)
1 /*	$NetBSD: clock.c,v 1.1 2011/03/03 05:59:37 kiyohara Exp $	*/
2 /*
3  * Copyright (c) 2011 KIYOHARA Takashi
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
19  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
24  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  * POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <lib/libsa/stand.h>
29 
30 #include <sh3/devreg.h>
31 #include <sh3/tmureg.h>
32 
33 #include "boot.h"
34 
35 void
tmu_init(void)36 tmu_init(void)
37 {
38 
39 	/* Enable TMU channel 0. */
40 	_reg_write_1(SH_(TOCR), TOCR_TCOE);
41 	_reg_write_2(SH_(TCR0), TCR_TPSC_P4);
42 	_reg_bset_1(SH_(TSTR), TSTR_STR0);
43 }
44 
45 void
delay(int n)46 delay(int n)
47 {
48 	int t1, t2, x;
49 
50 	x = n * 11;
51 	t1 = _reg_read_4(SH_(TCNT0));
52 	while (x > 0) {
53 		t2 = _reg_read_4(SH_(TCNT0));
54 		if (t2 > t1)
55 			x -= (t2 - t1 - 1);
56 		else
57 			x -= (t1 - t2);
58 		t1 = t2;
59 	}
60 }
61