63 lines
1.8 KiB
C
63 lines
1.8 KiB
C
/*
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* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*
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* You can also choose to distribute this program under the terms of
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* the Unmodified Binary Distribution Licence (as given in the file
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* COPYING.UBDL), provided that you have satisfied its requirements.
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*/
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FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
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#include <ipxe/bitbash.h>
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/** @file
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*
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* Bit-bashing interfaces
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*
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*/
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/**
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* Set/clear output bit
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*
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* @v basher Bit-bashing interface
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* @v bit_id Bit number
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* @v data Value to write
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*
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* If @c data is 0, a logic 0 will be written. If @c data is
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* non-zero, a logic 1 will be written.
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*/
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void write_bit ( struct bit_basher *basher, unsigned int bit_id,
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unsigned long data ) {
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basher->op->write ( basher, bit_id, ( data ? -1UL : 0 ) );
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}
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/**
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* Read input bit
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*
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* @v basher Bit-bashing interface
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* @v bit_id Bit number
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* @ret data Value read
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*
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* @c data will always be either 0 or -1UL. The idea is that the
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* caller can simply binary-AND the returned value with whatever mask
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* it needs to apply.
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*/
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int read_bit ( struct bit_basher *basher, unsigned int bit_id ) {
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return ( basher->op->read ( basher, bit_id ) ? -1UL : 0 );
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}
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