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

Last change on this file since 55 was 55, checked in by Tim Harvey, 2 years ago

rincon: added latest u-boot source

restored form server backup

Signed-off-by: Tim Harvey <tharvey@…>

File size: 3.1 KB
Line 
1/*
2 * U-boot - interrupts.c Interrupt related routines
3 *
4 * Copyright (c) 2005-2008 Analog Devices Inc.
5 *
6 * This file is based on interrupts.c
7 * Copyright 1996 Roman Zippel
8 * Copyright 1999 D. Jeff Dionne <jeff@uclinux.org>
9 * Copyright 2000-2001 Lineo, Inc. D. Jefff Dionne <jeff@lineo.ca>
10 * Copyright 2002 Arcturus Networks Inc. MaTed <mated@sympatico.ca>
11 * Copyright 2003 Metrowerks/Motorola
12 * Copyright 2003 Bas Vermeulen <bas@buyways.nl>,
13 *                      BuyWays B.V. (www.buyways.nl)
14 *
15 * (C) Copyright 2000-2004
16 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
17 *
18 * Licensed under the GPL-2 or later.
19 */
20
21#include <common.h>
22#include <config.h>
23#include <asm/blackfin.h>
24#include "cpu.h"
25
26static ulong timestamp;
27static ulong last_time;
28static int int_flag;
29
30int irq_flags;                  /* needed by asm-blackfin/system.h */
31
32/* Functions just to satisfy the linker */
33
34/*
35 * This function is derived from PowerPC code (read timebase as long long).
36 * On Blackfin it just returns the timer value.
37 */
38unsigned long long get_ticks(void)
39{
40        return get_timer(0);
41}
42
43/*
44 * This function is derived from PowerPC code (timebase clock frequency).
45 * On Blackfin it returns the number of timer ticks per second.
46 */
47ulong get_tbclk(void)
48{
49        ulong tbclk;
50
51        tbclk = CFG_HZ;
52        return tbclk;
53}
54
55void enable_interrupts(void)
56{
57        local_irq_restore(int_flag);
58}
59
60int disable_interrupts(void)
61{
62        local_irq_save(int_flag);
63        return 1;
64}
65
66void udelay(unsigned long usec)
67{
68        unsigned long delay, start, stop;
69        unsigned long cclk;
70        cclk = (CONFIG_CCLK_HZ);
71
72        while (usec > 1) {
73                /*
74                 * how many clock ticks to delay?
75                 *  - request(in useconds) * clock_ticks(Hz) / useconds/second
76                 */
77                if (usec < 1000) {
78                        delay = (usec * (cclk / 244)) >> 12;
79                        usec = 0;
80                } else {
81                        delay = (1000 * (cclk / 244)) >> 12;
82                        usec -= 1000;
83                }
84
85                asm volatile (" %0 = CYCLES;" : "=r" (start));
86                do {
87                        asm volatile (" %0 = CYCLES; " : "=r" (stop));
88                } while (stop - start < delay);
89        }
90
91        return;
92}
93
94#define MAX_TIM_LOAD    0xFFFFFFFF
95int timer_init(void)
96{
97        *pTCNTL = 0x1;
98        *pTSCALE = 0x0;
99        *pTCOUNT = MAX_TIM_LOAD;
100        *pTPERIOD = MAX_TIM_LOAD;
101        *pTCNTL = 0x7;
102        asm("CSYNC;");
103
104        timestamp = 0;
105        last_time = 0;
106
107        return 0;
108}
109
110/*
111 * Any network command or flash
112 * command is started get_timer shall
113 * be called before TCOUNT gets reset,
114 * to implement the accurate timeouts.
115 *
116 * How ever milliconds doesn't return
117 * the number that has been elapsed from
118 * the last reset.
119 *
120 * As get_timer is used in the u-boot
121 * only for timeouts this should be
122 * sufficient
123 */
124ulong get_timer(ulong base)
125{
126        ulong milisec;
127
128        /* Number of clocks elapsed */
129        ulong clocks = (MAX_TIM_LOAD - (*pTCOUNT));
130
131        /*
132         * Find if the TCOUNT is reset
133         * timestamp gives the number of times
134         * TCOUNT got reset
135         */
136        if (clocks < last_time)
137                timestamp++;
138        last_time = clocks;
139
140        /* Get the number of milliseconds */
141        milisec = clocks / (CONFIG_CCLK_HZ / 1000);
142
143        /*
144         * Find the number of millisonds that
145         * got elapsed before this TCOUNT cycle
146         */
147        milisec += timestamp * (MAX_TIM_LOAD / (CONFIG_CCLK_HZ / 1000));
148
149        return (milisec - base);
150}
151
152void reset_timer(void)
153{
154        timestamp = 0;
155}
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