cregit-Linux how code gets into the kernel

Release 4.12 include/linux/lp.h

Directory: include/linux
 * 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_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 */


#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;

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;
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


Overall Contributors

Linus Torvalds (pre-git)22490.69%1780.95%
Linus Torvalds124.86%14.76%
Dave Jones52.02%14.76%
David Howells41.62%14.76%
Matthias Kaehlcke20.81%14.76%
Directory: include/linux
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