freebsd-dev/sys/boot/arm/at91/libat91/getc.c

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/*-
* Copyright (c) 2006 M. Warner Losh. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This software is derived from software provided by kwikbyte without
* copyright as follows:
*
* No warranty, expressed or implied, is included with this software. It is
* provided "AS IS" and no warranty of any kind including statutory or aspects
* relating to merchantability or fitness for any purpose is provided. All
* intellectual property rights of others is maintained with the respective
* owners. This software is not copyrighted and is intended for reference
* only.
*
* $FreeBSD$
*/
#include "at91rm9200.h"
#include "at91rm9200_lowlevel.h"
#include "lib.h"
/*
* int getc(int seconds)
*
* Reads a character from the DBGU port, if one is available within about
* seconds seconds. It assumes that DBGU has already been initialized.
*/
int
getc(int seconds)
{
AT91PS_USART pUSART = (AT91PS_USART)AT91C_BASE_DBGU;
unsigned thisSecond;
// Clamp to 20s
if (seconds > 20)
seconds = 20;
thisSecond = GetSeconds();
seconds = thisSecond + seconds;
do {
if ((pUSART->US_CSR & AT91C_US_RXRDY))
return (pUSART->US_RHR & 0xFF);
thisSecond = GetSeconds();
} while (thisSecond != seconds);
return (-1);
}