ReactOS  0.4.15-dev-1206-g731eddf
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_ */