include/linux/lp.h

1 /* SPDX-License-Identifier: GPL-2.0 */
3  * usr/include/linux/lp.h c.1991-1992 James Wiegand
16 /* Magic numbers for defining port-device mappings */
17 #define LP_PARPORT_UNSPEC -4
18 #define LP_PARPORT_AUTO -3
19 #define LP_PARPORT_OFF -2
20 #define LP_PARPORT_NONE -1
26 #define LP_IRQ(minor)	lp_table[(minor)].dev->port->irq /* interrupt # */
33 #define LP_BASE(x)	lp_table[(x)].dev->port->base
71  * signals are active low.  An example is LP_STROBE, which must be programmed
72  * with 1 for being active and 0 for being inactive, because the strobe signal
73  * gets inverted, but it is also active low.
82 #define LP_PINTEN	0x10  /* high to read data in or-ed with data out */
83 #define LP_PSELECP	0x08  /* inverted output, active low */
84 #define LP_PINITP	0x04  /* unchanged output, active low */
85 #define LP_PAUTOLF	0x02  /* inverted output, active low */
89  * the value written to ports to test existence. PC-style ports will
90  * return the value written. AT-style ports will return 0. so why not