[golan] Add various new PCI device IDs
[ipxe.git] / src / drivers / bitbash / bitbash.c
1 /*
2 * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
3 *
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.
8 *
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.
13 *
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
17 * 02110-1301, USA.
18 *
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
22 */
23
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25
26 #include <ipxe/bitbash.h>
27
28 /** @file
29 *
30 * Bit-bashing interfaces
31 *
32 */
33
34 /**
35 * Set/clear output bit
36 *
37 * @v basher Bit-bashing interface
38 * @v bit_id Bit number
39 * @v data Value to write
40 *
41 * If @c data is 0, a logic 0 will be written. If @c data is
42 * non-zero, a logic 1 will be written.
43 */
44 void write_bit ( struct bit_basher *basher, unsigned int bit_id,
45 unsigned long data ) {
46 basher->op->write ( basher, bit_id, ( data ? -1UL : 0 ) );
47 }
48
49 /**
50 * Read input bit
51 *
52 * @v basher Bit-bashing interface
53 * @v bit_id Bit number
54 * @ret data Value read
55 *
56 * @c data will always be either 0 or -1UL. The idea is that the
57 * caller can simply binary-AND the returned value with whatever mask
58 * it needs to apply.
59 */
60 int read_bit ( struct bit_basher *basher, unsigned int bit_id ) {
61 return ( basher->op->read ( basher, bit_id ) ? -1UL : 0 );
62 }