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_ */ 42