ReactOS 0.4.15-dev-8419-g7f0e8a3
hardware.h
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1/*
2 * COPYRIGHT: See COPYING in the top level directory
3 * PROJECT: Parallel Port Function Driver
4 * FILE: drivers/parallel/parport/hardware.h
5 * PURPOSE: Hardware definitions
6 */
7
8#ifndef _HARDWARE_H_
9#define _HARDWARE_H_
10
11/*
12 * The following constants describe the various signals of the printer port
13 * hardware. Note that the hardware inverts some signals and that some
14 * signals are active low. An example is LP_STROBE, which must be programmed
15 * with 1 for being active and 0 for being inactive, because the strobe signal
16 * gets inverted, but it is also active low.
17 */
18
19/*
20 * bit defines for 8255 status port
21 * base + 1
22 * accessed with LP_S(minor), which gets the byte...
23 */
24#define LP_PBUSY 0x80 /* inverted input, active high */
25#define LP_PACK 0x40 /* unchanged input, active low */
26#define LP_POUTPA 0x20 /* unchanged input, active high */
27#define LP_PSELECD 0x10 /* unchanged input, active high */
28#define LP_PERRORP 0x08 /* unchanged input, active low */
29
30/*
31 * defines for 8255 control port
32 * base + 2
33 * accessed with LP_C(minor)
34 */
35#define LP_PINTEN 0x10
36#define LP_PSELECP 0x08 /* inverted output, active low */
37#define LP_PINITP 0x04 /* unchanged output, active low */
38#define LP_PAUTOLF 0x02 /* inverted output, active low */
39#define LP_PSTROBE 0x01 /* inverted output, active low */
40
41#endif /* _HARDWARE_H_ */