summaryrefslogtreecommitdiff
path: root/cpu/bf537/interrupts.c
blob: 853fa492c758d1d19a4221f880d261d549f39f5d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/*
 * U-boot - interrupts.c Interrupt related routines
 *
 * Copyright (c) 2005-2007 Analog Devices Inc.
 *
 * This file is based on interrupts.c
 * Copyright 1996 Roman Zippel
 * Copyright 1999 D. Jeff Dionne <jeff@uclinux.org>
 * Copyright 2000-2001 Lineo, Inc. D. Jefff Dionne <jeff@lineo.ca>
 * Copyright 2002 Arcturus Networks Inc. MaTed <mated@sympatico.ca>
 * Copyright 2003 Metrowerks/Motorola
 * Copyright 2003 Bas Vermeulen <bas@buyways.nl>,
 *			BuyWays B.V. (www.buyways.nl)
 *
 * (C) Copyright 2000-2004
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.

 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 * MA 02110-1301 USA
 */

#include <common.h>
#include <config.h>
#include <asm/blackfin.h>
#include "cpu.h"

static ulong timestamp;
static ulong last_time;
static int int_flag;

int irq_flags;			/* needed by asm-blackfin/system.h */

/* Functions just to satisfy the linker */

/*
 * This function is derived from PowerPC code (read timebase as long long).
 * On BF533 it just returns the timer value.
 */
unsigned long long get_ticks(void)
{
	return get_timer(0);
}

/*
 * This function is derived from PowerPC code (timebase clock frequency).
 * On BF533 it returns the number of timer ticks per second.
 */
ulong get_tbclk (void)
{
	ulong tbclk;

	tbclk = CFG_HZ;
	return tbclk;
}

void enable_interrupts(void)
{
}

int disable_interrupts(void)
{
	return 1;
}

int interrupt_init(void)
{
	return (0);
}

void udelay(unsigned long usec)
{
	unsigned long delay, start, stop;
	unsigned long cclk;
	cclk = (CONFIG_CCLK_HZ);

	while (usec > 1) {
		/*
		 * how many clock ticks to delay?
		 *  - request(in useconds) * clock_ticks(Hz) / useconds/second
		 */
		if (usec < 1000) {
			delay = (usec * (cclk / 244)) >> 12;
			usec = 0;
		} else {
			delay = (1000 * (cclk / 244)) >> 12;
			usec -= 1000;
		}

		asm volatile (" %0 = CYCLES;":"=r" (start));
		do {
			asm volatile (" %0 = CYCLES; ":"=r" (stop));
		} while (stop - start < delay);
	}

	return;
}

void timer_init(void)
{
	*pTCNTL = 0x1;
	*pTSCALE = 0x0;
	*pTCOUNT = MAX_TIM_LOAD;
	*pTPERIOD = MAX_TIM_LOAD;
	*pTCNTL = 0x7;
	asm("CSYNC;");

	timestamp = 0;
	last_time = 0;
}

/* Any network command or flash
 * command is started get_timer shall
 * be called before TCOUNT gets reset,
 * to implement the accurate timeouts.
 *
 * How ever milliconds doesn't return
 * the number that has been elapsed from
 * the last reset.
 *
 *  As get_timer is used in the u-boot
 *  only for timeouts this should be
 *  sufficient
 */
ulong get_timer(ulong base)
{
	ulong milisec;

	/* Number of clocks elapsed */
	ulong clocks = (MAX_TIM_LOAD - (*pTCOUNT));

	/**
	 * Find if the TCOUNT is reset
	 * timestamp gives the number of times
	 * TCOUNT got reset
	 */
	if (clocks < last_time)
		timestamp++;
	last_time = clocks;

	/* Get the number of milliseconds */
	milisec = clocks / (CONFIG_CCLK_HZ / 1000);

	/**
	 * Find the number of millisonds
	 * that got elapsed before this TCOUNT cycle
	 */
	milisec += timestamp * (MAX_TIM_LOAD / (CONFIG_CCLK_HZ / 1000));

	return (milisec - base);
}

void reset_timer (void)
{
	timestamp = 0;
}