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			160 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			160 lines
		
	
	
		
			3.2 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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	bfin_write_TCNTL(0x1);
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	CSYNC();
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	bfin_write_TSCALE(0x0);
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	bfin_write_TCOUNT(MAX_TIM_LOAD);
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	bfin_write_TPERIOD(MAX_TIM_LOAD);
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	bfin_write_TCNTL(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 - bfin_read_TCOUNT());
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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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