iPXE
bitbash.c
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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 }
struct bit_basher_operations * op
Bit-bashing operations.
Definition: bitbash.h:57
Bit-bashing interfaces.
int(* read)(struct bit_basher *basher, unsigned int bit_id)
Read input bit.
Definition: bitbash.h:51
A bit-bashing interface.
Definition: bitbash.h:55
int read_bit(struct bit_basher *basher, unsigned int bit_id)
Read input bit.
Definition: bitbash.c:60
void(* write)(struct bit_basher *basher, unsigned int bit_id, unsigned long data)
Set/clear output bit.
Definition: bitbash.h:41
FILE_LICENCE(GPL2_OR_LATER_OR_UBDL)
struct arbelprm_port_state_change_st data
Message.
Definition: arbel.h:12
void write_bit(struct bit_basher *basher, unsigned int bit_id, unsigned long data)
Set/clear output bit.
Definition: bitbash.c:44