u-boot/cpu/bf537/interrupts.c

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/*
* 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 <asm/machdep.h>
#include <asm/irq.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)
{
restore_flags(int_flag);
}
int disable_interrupts(void)
{
save_and_cli(int_flag);
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;
}