/* * Useful info describing the parallel port device. * * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet * Copyright (C) 2001 O'Reilly & Associates * * The source code in this file can be freely used, adapted, * and redistributed in source or binary form, so long as an * acknowledgment appears in derived source files.  The citation * should list that the code comes from the book "Linux Device * Drivers" by Alessandro Rubini and Jonathan Corbet, published * by O'Reilly & Associates.   No warranty is attached; * we cannot take responsibility for errors or fitness for use. * *//* * Register offsets */#define SP_DATA    0x00#define SP_STATUS  0x01#define SP_CONTROL 0x02#define SP_NPORTS     3/* * Status register bits. */#define SP_SR_BUSY 	0x80#define SP_SR_ACK	0x40#define SP_SR_PAPER	0x20#define SP_SR_ONLINE	0x10#define SP_SR_ERR	0x08/* * Control register. */#define SP_CR_IRQ	0x10#define SP_CR_SELECT	0x08#define SP_CR_INIT	0x04#define SP_CR_AUTOLF	0x02#define SP_CR_STROBE	0x01/* * Minimum space before waking up a writer. */#define SP_MIN_SPACE	PAGE_SIZE/2