interrupts.c
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/*
* U-boot - interrupts.c Interrupt related routines
*
* Copyright (c) 2005-2008 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.
*
* Licensed under the GPL-2 or later.
*/
#include <common.h>
#include <config.h>
#include <watchdog.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 Blackfin 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 Blackfin it returns the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
ulong tbclk;
tbclk = CONFIG_SYS_HZ;
return tbclk;
}
void enable_interrupts(void)
{
local_irq_restore(int_flag);
}
int disable_interrupts(void)
{
local_irq_save(int_flag);
return 1;
}
void __udelay(unsigned long usec)
{
unsigned long delay, start, stop;
unsigned long cclk;
cclk = (CONFIG_CCLK_HZ);
while (usec > 1) {
WATCHDOG_RESET();
/*
* 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;
}
#define MAX_TIM_LOAD 0xFFFFFFFF
int timer_init(void)
{
*pTCNTL = 0x1;
CSYNC();
*pTSCALE = 0x0;
*pTCOUNT = MAX_TIM_LOAD;
*pTPERIOD = MAX_TIM_LOAD;
*pTCNTL = 0x7;
CSYNC();
timestamp = 0;
last_time = 0;
return 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)
{
timer_init();
}