2 * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
20 FILE_LICENCE ( GPL2_OR_LATER );
22 #include <ipxe/bitbash.h>
26 * Bit-bashing interfaces
31 * Set/clear output bit
33 * @v basher Bit-bashing interface
34 * @v bit_id Bit number
35 * @v data Value to write
37 * If @c data is 0, a logic 0 will be written. If @c data is
38 * non-zero, a logic 1 will be written.
40 void write_bit ( struct bit_basher *basher, unsigned int bit_id,
41 unsigned long data ) {
42 basher->op->write ( basher, bit_id, ( data ? -1UL : 0 ) );
48 * @v basher Bit-bashing interface
49 * @v bit_id Bit number
50 * @ret data Value read
52 * @c data will always be either 0 or -1UL. The idea is that the
53 * caller can simply binary-AND the returned value with whatever mask
56 int read_bit ( struct bit_basher *basher, unsigned int bit_id ) {
57 return ( basher->op->read ( basher, bit_id ) ? -1UL : 0 );