/*
   * usr/include/linux/lp.h c.1991-1992 James Wiegand
   * many modifications copyright (C) 1992 Michael K. Johnson
   * Interrupt support added 1993 Nigel Gamble
   * Removed 8255 status defines from inside __KERNEL__ Marcelo Tosatti 
   */

  #ifndef _LINUX_LP_H
  #define _LINUX_LP_H

  
  #include <linux/wait.h>

  #include <linux/mutex.h>

  #include <uapi/linux/lp.h>

  
  /* Magic numbers for defining port-device mappings */
  #define LP_PARPORT_UNSPEC -4
  #define LP_PARPORT_AUTO -3
  #define LP_PARPORT_OFF -2
  #define LP_PARPORT_NONE -1
  
  #define LP_F(minor)	lp_table[(minor)].flags		/* flags for busy, etc. */
  #define LP_CHAR(minor)	lp_table[(minor)].chars		/* busy timeout */
  #define LP_TIME(minor)	lp_table[(minor)].time		/* wait time */
  #define LP_WAIT(minor)	lp_table[(minor)].wait		/* strobe wait */
  #define LP_IRQ(minor)	lp_table[(minor)].dev->port->irq /* interrupt # */
  					/* PARPORT_IRQ_NONE means polled */
  #ifdef LP_STATS
  #define LP_STAT(minor)	lp_table[(minor)].stats		/* statistics area */
  #endif
  #define LP_BUFFER_SIZE PAGE_SIZE
  
  #define LP_BASE(x)	lp_table[(x)].dev->port->base
  
  #ifdef LP_STATS
  struct lp_stats {
  	unsigned long chars;
  	unsigned long sleeps;
  	unsigned int maxrun;
  	unsigned int maxwait;
  	unsigned int meanwait;
  	unsigned int mdev;
  };
  #endif
  
  struct lp_struct {
  	struct pardevice *dev;
  	unsigned long flags;
  	unsigned int chars;
  	unsigned int time;
  	unsigned int wait;
  	char *lp_buffer;
  #ifdef LP_STATS
  	unsigned int lastcall;
  	unsigned int runchars;
  	struct lp_stats stats;
  #endif
  	wait_queue_head_t waitq;
  	unsigned int last_error;

  	struct mutex port_mutex;

  	wait_queue_head_t dataq;
  	long timeout;
  	unsigned int best_mode;
  	unsigned int current_mode;
  	unsigned long bits;
  };
  
  /*
   * The following constants describe the various signals of the printer port
   * hardware.  Note that the hardware inverts some signals and that some
   * signals are active low.  An example is LP_STROBE, which must be programmed
   * with 1 for being active and 0 for being inactive, because the strobe signal
   * gets inverted, but it is also active low.
   */
  
  
  /* 
   * defines for 8255 control port
   * base + 2 
   * accessed with LP_C(minor)
   */
  #define LP_PINTEN	0x10  /* high to read data in or-ed with data out */
  #define LP_PSELECP	0x08  /* inverted output, active low */
  #define LP_PINITP	0x04  /* unchanged output, active low */
  #define LP_PAUTOLF	0x02  /* inverted output, active low */
  #define LP_PSTROBE	0x01  /* short high output on raising edge */
  
  /* 
   * the value written to ports to test existence. PC-style ports will 
   * return the value written. AT-style ports will return 0. so why not
   * make them the same ? 
   */
  #define LP_DUMMY	0x00
  
  /*
   * This is the port delay time, in microseconds.
   * It is used only in the lp_init() and lp_reset() routine.
   */
  #define LP_DELAY 	50
  
  #endif