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Aubrey Li65458982007-03-20 18:16:24 +08001/*
2 * U-boot - interrupts.c Interrupt related routines
3 *
Aubrey Li155fd762007-04-05 18:31:18 +08004 * Copyright (c) 2005-2007 Analog Devices Inc.
Aubrey Li65458982007-03-20 18:16:24 +08005 *
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 * See file CREDITS for list of people who contributed to this
19 * project.
20 *
21 * This program is free software; you can redistribute it and/or
22 * modify it under the terms of the GNU General Public License as
23 * published by the Free Software Foundation; either version 2 of
24 * the License, or (at your option) any later version.
25 *
26 * This program is distributed in the hope that it will be useful,
27 * but WITHOUT ANY WARRANTY; without even the implied warranty of
28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
29 * GNU General Public License for more details.
30 *
31 * You should have received a copy of the GNU General Public License
32 * along with this program; if not, write to the Free Software
Aubrey Li155fd762007-04-05 18:31:18 +080033 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
34 * MA 02110-1301 USA
Aubrey Li65458982007-03-20 18:16:24 +080035 */
36
37#include <common.h>
38#include <asm/machdep.h>
39#include <asm/irq.h>
40#include <config.h>
41#include <asm/blackfin.h>
42#include "cpu.h"
43
44static ulong timestamp;
45static ulong last_time;
46static int int_flag;
47
48int irq_flags; /* needed by asm-blackfin/system.h */
49
50/* Functions just to satisfy the linker */
51
52/*
53 * This function is derived from PowerPC code (read timebase as long long).
54 * On BF561 it just returns the timer value.
55 */
56unsigned long long get_ticks(void)
57{
58 return get_timer(0);
59}
60
61/*
62 * This function is derived from PowerPC code (timebase clock frequency).
63 * On BF561 it returns the number of timer ticks per second.
64 */
65ulong get_tbclk(void)
66{
67 ulong tbclk;
68
69 tbclk = CFG_HZ;
70 return tbclk;
71}
72
73void enable_interrupts(void)
74{
75 restore_flags(int_flag);
76}
77
78int disable_interrupts(void)
79{
80 save_and_cli(int_flag);
81 return 1;
82}
83
84int interrupt_init(void)
85{
86 return (0);
87}
88
89void udelay(unsigned long usec)
90{
91 unsigned long delay, start, stop;
92 unsigned long cclk;
93 cclk = (CONFIG_CCLK_HZ);
94
95 while (usec > 1) {
96 /*
97 * how many clock ticks to delay?
98 * - request(in useconds) * clock_ticks(Hz) / useconds/second
99 */
100 if (usec < 1000) {
101 delay = (usec * (cclk / 244)) >> 12;
102 usec = 0;
103 } else {
104 delay = (1000 * (cclk / 244)) >> 12;
105 usec -= 1000;
106 }
107
108 asm volatile (" %0 = CYCLES;":"=r" (start));
109 do {
110 asm volatile (" %0 = CYCLES; ":"=r" (stop));
111 } while (stop - start < delay);
112 }
113
114 return;
115}
116
117void timer_init(void)
118{
119 *pTCNTL = 0x1;
120 *pTSCALE = 0x0;
121 *pTCOUNT = MAX_TIM_LOAD;
122 *pTPERIOD = MAX_TIM_LOAD;
123 *pTCNTL = 0x7;
124 asm("CSYNC;");
125
126 timestamp = 0;
127 last_time = 0;
128}
129
130/*
131 * Any network command or flash
132 * command is started get_timer shall
133 * be called before TCOUNT gets reset,
134 * to implement the accurate timeouts.
135 *
136 * How ever milliconds doesn't return
137 * the number that has been elapsed from
138 * the last reset.
139 *
140 * As get_timer is used in the u-boot
141 * only for timeouts this should be
142 * sufficient
143 */
144ulong get_timer(ulong base)
145{
146 ulong milisec;
147
148 /* Number of clocks elapsed */
149 ulong clocks = (MAX_TIM_LOAD - (*pTCOUNT));
150
151 /*
152 * Find if the TCOUNT is reset
153 * timestamp gives the number of times
154 * TCOUNT got reset
155 */
156 if (clocks < last_time)
157 timestamp++;
158 last_time = clocks;
159
160 /* Get the number of milliseconds */
161 milisec = clocks / (CONFIG_CCLK_HZ / 1000);
162
163 /*
164 * Find the number of millisonds
165 * that got elapsed before this TCOUNT
166 * cycle
167 */
168 milisec += timestamp * (MAX_TIM_LOAD / (CONFIG_CCLK_HZ / 1000));
169
170 return (milisec - base);
171}