source: SVN/rincon/u-boot/cpu/lh7a40x/interrupts.c @ 55

Last change on this file since 55 was 55, checked in by Tim Harvey, 22 months ago

rincon: added latest u-boot source

restored form server backup

Signed-off-by: Tim Harvey <tharvey@…>

File size: 3.7 KB
Line 
1/*
2 * (C) Copyright 2002
3 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
4 * Marius Groeger <mgroeger@sysgo.de>
5 *
6 * (C) Copyright 2002
7 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
8 * Alex Zuepke <azu@sysgo.de>
9 *
10 * (C) Copyright 2002
11 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
12 *
13 * See file CREDITS for list of people who contributed to this
14 * project.
15 *
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License as
18 * published by the Free Software Foundation; either version 2 of
19 * the License, or (at your option) any later version.
20 *
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24 * GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
29 * MA 02111-1307 USA
30 */
31
32#include <common.h>
33#include <arm920t.h>
34#include <lh7a40x.h>
35
36static ulong timer_load_val = 0;
37
38/* macro to read the 16 bit timer */
39static inline ulong READ_TIMER(void)
40{
41        lh7a40x_timers_t* timers = LH7A40X_TIMERS_PTR;
42        lh7a40x_timer_t* timer = &timers->timer1;
43
44        return (timer->value & 0x0000ffff);
45}
46
47static ulong timestamp;
48static ulong lastdec;
49
50int interrupt_init (void)
51{
52        lh7a40x_timers_t* timers = LH7A40X_TIMERS_PTR;
53        lh7a40x_timer_t* timer = &timers->timer1;
54
55        /* a periodic timer using the 508kHz source */
56        timer->control = (TIMER_PER | TIMER_CLK508K);
57
58        if (timer_load_val == 0) {
59                /*
60                 * 10ms period with 508.469kHz clock = 5084
61                 */
62                timer_load_val = CFG_HZ/100;
63        }
64
65        /* load value for 10 ms timeout */
66        lastdec = timer->load = timer_load_val;
67
68        /* auto load, start timer */
69        timer->control = timer->control | TIMER_EN;
70        timestamp = 0;
71
72        return (0);
73}
74
75/*
76 * timer without interrupts
77 */
78
79void reset_timer (void)
80{
81        reset_timer_masked ();
82}
83
84ulong get_timer (ulong base)
85{
86        return (get_timer_masked() - base);
87}
88
89void set_timer (ulong t)
90{
91        timestamp = t;
92}
93
94void udelay (unsigned long usec)
95{
96        ulong tmo,tmp;
97
98        /* normalize */
99        if (usec >= 1000) {
100                tmo = usec / 1000;
101                tmo *= CFG_HZ;
102                tmo /= 1000;
103        }
104        else {
105                if (usec > 1) {
106                        tmo = usec * CFG_HZ;
107                        tmo /= (1000*1000);
108                }
109                else
110                        tmo = 1;
111        }
112
113        /* check for rollover during this delay */
114        tmp = get_timer (0);
115        if ((tmp + tmo) < tmp )
116                reset_timer_masked();  /* timer would roll over */
117        else
118                tmo += tmp;
119
120        while (get_timer_masked () < tmo);
121}
122
123void reset_timer_masked (void)
124{
125        /* reset time */
126        lastdec = READ_TIMER();
127        timestamp = 0;
128}
129
130ulong get_timer_masked (void)
131{
132        ulong now = READ_TIMER();
133
134        if (lastdec >= now) {
135                /* normal mode */
136                timestamp += (lastdec - now);
137        } else {
138                /* we have an overflow ... */
139                timestamp += ((lastdec + timer_load_val) - now);
140        }
141        lastdec = now;
142
143        return timestamp;
144}
145
146void udelay_masked (unsigned long usec)
147{
148        ulong tmo;
149        ulong endtime;
150        signed long diff;
151
152        /* normalize */
153        if (usec >= 1000) {
154                tmo = usec / 1000;
155                tmo *= CFG_HZ;
156                tmo /= 1000;
157        } else {
158                if (usec > 1) {
159                        tmo = usec * CFG_HZ;
160                        tmo /= (1000*1000);
161                } else {
162                        tmo = 1;
163                }
164        }
165
166        endtime = get_timer_masked () + tmo;
167
168        do {
169                ulong now = get_timer_masked ();
170                diff = endtime - now;
171        } while (diff >= 0);
172}
173
174/*
175 * This function is derived from PowerPC code (read timebase as long long).
176 * On ARM it just returns the timer value.
177 */
178unsigned long long get_ticks(void)
179{
180        return get_timer(0);
181}
182
183/*
184 * This function is derived from PowerPC code (timebase clock frequency).
185 * On ARM it returns the number of timer ticks per second.
186 */
187ulong get_tbclk (void)
188{
189        ulong tbclk;
190
191        tbclk = timer_load_val * 100;
192
193        return tbclk;
194}
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