reactos/drivers/parallel/parport/hardware.h

   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_ */