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https://github.com/brain-hackers/u-boot-brain
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3eb90bad65
According to the PPC reference implementation the udelay() function is responsible for resetting the watchdog timer as frequently as needed. Most other architectures do not meet that requirement, so long-running operations might result in a watchdog reset. This patch adds a generic udelay() function which takes care of resetting the watchdog before calling an architecture-specific __udelay(). Signed-off-by: Ingo van Lil <inguin@gmx.de>
160 lines
3.1 KiB
C
160 lines
3.1 KiB
C
/*
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* U-boot - interrupts.c Interrupt related routines
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*
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* Copyright (c) 2005-2008 Analog Devices Inc.
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*
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* This file is based on interrupts.c
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* Copyright 1996 Roman Zippel
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* Copyright 1999 D. Jeff Dionne <jeff@uclinux.org>
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* Copyright 2000-2001 Lineo, Inc. D. Jefff Dionne <jeff@lineo.ca>
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* Copyright 2002 Arcturus Networks Inc. MaTed <mated@sympatico.ca>
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* Copyright 2003 Metrowerks/Motorola
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* Copyright 2003 Bas Vermeulen <bas@buyways.nl>,
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* BuyWays B.V. (www.buyways.nl)
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*
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* (C) Copyright 2000-2004
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* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
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*
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* Licensed under the GPL-2 or later.
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*/
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#include <common.h>
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#include <config.h>
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#include <watchdog.h>
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#include <asm/blackfin.h>
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#include "cpu.h"
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static ulong timestamp;
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static ulong last_time;
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static int int_flag;
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int irq_flags; /* needed by asm-blackfin/system.h */
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/* Functions just to satisfy the linker */
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/*
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* This function is derived from PowerPC code (read timebase as long long).
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* On Blackfin it just returns the timer value.
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*/
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unsigned long long get_ticks(void)
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{
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return get_timer(0);
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}
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/*
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* This function is derived from PowerPC code (timebase clock frequency).
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* On Blackfin it returns the number of timer ticks per second.
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*/
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ulong get_tbclk(void)
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{
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ulong tbclk;
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tbclk = CONFIG_SYS_HZ;
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return tbclk;
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}
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void enable_interrupts(void)
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{
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local_irq_restore(int_flag);
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}
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int disable_interrupts(void)
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{
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local_irq_save(int_flag);
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return 1;
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}
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void __udelay(unsigned long usec)
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{
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unsigned long delay, start, stop;
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unsigned long cclk;
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cclk = (CONFIG_CCLK_HZ);
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while (usec > 1) {
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WATCHDOG_RESET();
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/*
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* how many clock ticks to delay?
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* - request(in useconds) * clock_ticks(Hz) / useconds/second
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*/
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if (usec < 1000) {
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delay = (usec * (cclk / 244)) >> 12;
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usec = 0;
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} else {
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delay = (1000 * (cclk / 244)) >> 12;
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usec -= 1000;
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}
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asm volatile (" %0 = CYCLES;" : "=r" (start));
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do {
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asm volatile (" %0 = CYCLES; " : "=r" (stop));
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} while (stop - start < delay);
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}
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return;
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}
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#define MAX_TIM_LOAD 0xFFFFFFFF
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int timer_init(void)
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{
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*pTCNTL = 0x1;
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CSYNC();
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*pTSCALE = 0x0;
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*pTCOUNT = MAX_TIM_LOAD;
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*pTPERIOD = MAX_TIM_LOAD;
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*pTCNTL = 0x7;
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CSYNC();
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timestamp = 0;
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last_time = 0;
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return 0;
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}
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/*
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* Any network command or flash
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* command is started get_timer shall
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* be called before TCOUNT gets reset,
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* to implement the accurate timeouts.
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*
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* How ever milliconds doesn't return
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* the number that has been elapsed from
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* the last reset.
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*
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* As get_timer is used in the u-boot
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* only for timeouts this should be
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* sufficient
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*/
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ulong get_timer(ulong base)
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{
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ulong milisec;
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/* Number of clocks elapsed */
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ulong clocks = (MAX_TIM_LOAD - (*pTCOUNT));
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/*
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* Find if the TCOUNT is reset
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* timestamp gives the number of times
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* TCOUNT got reset
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*/
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if (clocks < last_time)
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timestamp++;
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last_time = clocks;
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/* Get the number of milliseconds */
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milisec = clocks / (CONFIG_CCLK_HZ / 1000);
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/*
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* Find the number of millisonds that
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* got elapsed before this TCOUNT cycle
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*/
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milisec += timestamp * (MAX_TIM_LOAD / (CONFIG_CCLK_HZ / 1000));
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return (milisec - base);
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}
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void reset_timer(void)
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{
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timer_init();
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}
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