source: SVN/rincon/u-boot/cpu/arm1136/omap24xx/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: 4.4 KB
Line 
1/*
2 * (C) Copyright 2004
3 * Texas Instruments
4 * Richard Woodruff <r-woodruff2@ti.com>
5 *
6 * (C) Copyright 2002
7 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
8 * Marius Groeger <mgroeger@sysgo.de>
9 * Alex Zuepke <azu@sysgo.de>
10 *
11 * (C) Copyright 2002
12 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
13 *
14 * See file CREDITS for list of people who contributed to this
15 * project.
16 *
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License as
19 * published by the Free Software Foundation; either version 2 of
20 * the License, or (at your option) any later version.
21 *
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
25 * GNU General Public License for more details.
26 *
27 * You should have received a copy of the GNU General Public License
28 * along with this program; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
30 * MA 02111-1307 USA
31 */
32
33#include <common.h>
34#include <asm/arch/bits.h>
35#include <asm/arch/omap2420.h>
36
37#define TIMER_LOAD_VAL 0
38
39/* macro to read the 32 bit timer */
40#define READ_TIMER (*((volatile ulong *)(CFG_TIMERBASE+TCRR)))
41
42static ulong timestamp;
43static ulong lastinc;
44
45/* nothing really to do with interrupts, just starts up a counter. */
46int interrupt_init (void)
47{
48        int32_t val;
49
50        /* Start the counter ticking up */
51        *((int32_t *) (CFG_TIMERBASE + TLDR)) = TIMER_LOAD_VAL; /* reload value on overflow*/
52        val = (CFG_PVT << 2) | BIT5 | BIT1 | BIT0;              /* mask to enable timer*/
53        *((int32_t *) (CFG_TIMERBASE + TCLR)) = val;    /* start timer */
54
55        reset_timer_masked(); /* init the timestamp and lastinc value */
56
57        return(0);
58}
59/*
60 * timer without interrupts
61 */
62void reset_timer (void)
63{
64        reset_timer_masked ();
65}
66
67ulong get_timer (ulong base)
68{
69        return get_timer_masked () - base;
70}
71
72void set_timer (ulong t)
73{
74        timestamp = t;
75}
76
77/* delay x useconds AND perserve advance timstamp value */
78void udelay (unsigned long usec)
79{
80        ulong tmo, tmp;
81
82        if (usec >= 1000) {                     /* if "big" number, spread normalization to seconds */
83                tmo = usec / 1000;              /* start to normalize for usec to ticks per sec */
84                tmo *= CFG_HZ;                  /* find number of "ticks" to wait to achieve target */
85                tmo /= 1000;                    /* finish normalize. */
86        } else {                                        /* else small number, don't kill it prior to HZ multiply */
87                tmo = usec * CFG_HZ;
88                tmo /= (1000*1000);
89        }
90
91        tmp = get_timer (0);            /* get current timestamp */
92        if ( (tmo + tmp + 1) < tmp )/* if setting this forward will roll time stamp */
93                reset_timer_masked ();  /* reset "advancing" timestamp to 0, set lastinc value */
94        else
95                tmo     += tmp;                         /* else, set advancing stamp wake up time */
96        while (get_timer_masked () < tmo)/* loop till event */
97                /*NOP*/;
98}
99
100void reset_timer_masked (void)
101{
102        /* reset time */
103        lastinc = READ_TIMER;           /* capture current incrementer value time */
104        timestamp = 0;                          /* start "advancing" time stamp from 0 */
105}
106
107ulong get_timer_masked (void)
108{
109        ulong now = READ_TIMER;         /* current tick value */
110
111        if (now >= lastinc)                     /* normal mode (non roll) */
112                timestamp += (now - lastinc); /* move stamp fordward with absoulte diff ticks */
113        else                                            /* we have rollover of incrementer */
114                timestamp += (0xFFFFFFFF - lastinc) + now;
115        lastinc = now;
116        return timestamp;
117}
118
119/* waits specified delay value and resets timestamp */
120void udelay_masked (unsigned long usec)
121{
122        ulong tmo;
123        ulong endtime;
124        signed long diff;
125
126        if (usec >= 1000) {                     /* if "big" number, spread normalization to seconds */
127                tmo = usec / 1000;              /* start to normalize for usec to ticks per sec */
128                tmo *= CFG_HZ;                  /* find number of "ticks" to wait to achieve target */
129                tmo /= 1000;                    /* finish normalize. */
130        } else {                                        /* else small number, don't kill it prior to HZ multiply */
131                tmo = usec * CFG_HZ;
132                tmo /= (1000*1000);
133        }
134        endtime = get_timer_masked () + tmo;
135
136        do {
137                ulong now = get_timer_masked ();
138                diff = endtime - now;
139        } while (diff >= 0);
140}
141
142/*
143 * This function is derived from PowerPC code (read timebase as long long).
144 * On ARM it just returns the timer value.
145 */
146unsigned long long get_ticks(void)
147{
148        return get_timer(0);
149}
150/*
151 * This function is derived from PowerPC code (timebase clock frequency).
152 * On ARM it returns the number of timer ticks per second.
153 */
154ulong get_tbclk (void)
155{
156        ulong tbclk;
157        tbclk = CFG_HZ;
158        return tbclk;
159}
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