- Drop all '@brief's, they're not needed as we use JAVADOC_AUTOBRIEF. The first sentence of every description will be treated as the '@brief' automatically. - Also, put all documentation/descriptions on top of the Doxygen-comments, and put the '@foo' keywords at the bottom of the comments for consistency. - Change comments for SEEK_SET/SEEK_CUR/SEEK_END from '/**@def' to '/**<' in order to make them appear in the output. - Drop all explicit '@struct' lines (which are optional; Doxygen will figure out that it's a struct if the comment is right before the struct). - Fix various typos, whitespace issues, etc. - Fix incorrect @param variable names, e.g. change '@param n foobar' to '@param s foobar' if the variable is named 's'. Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de> Acked-by: Uwe Hermann <uwe@hermann-uwe.de> git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3555 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
		
			
				
	
	
		
			123 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			123 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * This file is part of the libpayload project.
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 *
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 * Copyright (C) 2008 Advanced Micro Devices, Inc.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. The name of the author may not be used to endorse or promote products
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 *    derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 */
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/**
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 * @file i386/timer.c
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 * i386 specific timer routines
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 */
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#include <libpayload.h>
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#include <arch/rdtsc.h>
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/**
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 * @ingroup arch
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 * Global variable containing the speed of the processor in KHz.
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 */
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u32 cpu_khz;
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/**
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 * Calculate the speed of the processor for use in delays.
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 *
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 * @return The CPU speed in kHz.
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 */
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unsigned int get_cpu_speed(void)
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{
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	unsigned long long start, end;
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	/* Set up the PPC port - disable the speaker, enable the T2 gate. */
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	outb((inb(0x61) & ~0x02) | 0x01, 0x61);
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	/* Set the PIT to Mode 0, counter 2, word access. */
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	outb(0xB0, 0x43);
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	/* Load the counter with 0xffff. */
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	outb(0xff, 0x42);
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	outb(0xff, 0x42);
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	/* Read the number of ticks during the period. */
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	start = rdtsc();
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	while (!(inb(0x61) & 0x20)) ;
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	end = rdtsc();
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	/*
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	 * The clock rate is 1193180 Hz, the number of milliseconds for a
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	 * period of 0xffff is 1193180 / (0xFFFF * 1000) or .0182.
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	 * Multiply that by the number of measured clocks to get the kHz value.
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	 */
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	cpu_khz = (unsigned int)((end - start) * 1193180U / (1000 * 0xffff));
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	return cpu_khz;
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}
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static inline void _delay(unsigned int delta)
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{
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	unsigned long long timeout = rdtsc() + delta;
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	while (rdtsc() < timeout) ;
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}
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/**
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 * Delay for a specified number of nanoseconds.
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 *
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 * @param n Number of nanoseconds to delay for.
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 */
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void ndelay(unsigned int n)
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{
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	_delay(n * cpu_khz / 1000000);
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}
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/**
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 * Delay for a specified number of microseconds.
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 *
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 * @param n Number of microseconds to delay for.
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 */
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void udelay(unsigned int n)
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{
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	_delay(n * cpu_khz / 1000);
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}
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/**
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 * Delay for a specified number of milliseconds.
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 *
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 * @param m Number of milliseconds to delay for.
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 */
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void mdelay(unsigned int m)
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{
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	_delay(m * cpu_khz);
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}
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/**
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 * Delay for a specified number of seconds.
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 *
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 * @param s Number of seconds to delay for.
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 */
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void delay(unsigned int s)
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{
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	_delay(s * cpu_khz * 1000);
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}
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