lp.h

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/*
 * 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