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/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <gpxe/bitbash.h>
/** @file
*
* Bit-bashing interfaces
*
*/
/**
* Set/clear output bit
*
* @v basher Bit-bashing interface
* @v bit_id Bit number
* @v data Value to write
*
* If @c data is 0, a logic 0 will be written. If @c data is
* non-zero, a logic 1 will be written.
*/
void write_bit ( struct bit_basher *basher, unsigned int bit_id,
unsigned long data ) {
basher->op->write ( basher, bit_id, ( data ? -1UL : 0 ) );
}
/**
* Read input bit
*
* @v basher Bit-bashing interface
* @v bit_id Bit number
* @ret data Value read
*
* @c data will always be either 0 or -1UL. The idea is that the
* caller can simply binary-AND the returned value with whatever mask
* it needs to apply.
*/
int read_bit ( struct bit_basher *basher, unsigned int bit_id ) {
return ( basher->op->read ( basher, bit_id ) ? -1UL : 0 );
}
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