linux/drivers/comedi/drivers/comedi_parport.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * comedi_parport.c
 * Comedi driver for standard parallel port
 *
 * For more information see:
 *	http://retired.beyondlogic.org/spp/parallel.htm
 *
 * COMEDI - Linux Control and Measurement Device Interface
 * Copyright (C) 1998,2001 David A. Schleef <[email protected]>
 */

/*
 * Driver: comedi_parport
 * Description: Standard PC parallel port
 * Author: ds
 * Status: works in immediate mode
 * Devices: [standard] parallel port (comedi_parport)
 * Updated: Tue, 30 Apr 2002 21:11:45 -0700
 *
 * A cheap and easy way to get a few more digital I/O lines. Steal
 * additional parallel ports from old computers or your neighbors'
 * computers.
 *
 * Option list:
 *   0: I/O port base for the parallel port.
 *   1: IRQ (optional)
 *
 * Parallel Port Lines:
 *
 *	 pin   subdev  chan  type  name
 *	-----  ------  ----  ----  --------------
 *	  1      2       0    DO   strobe
 *	  2      0       0    DIO  data 0
 *	  3      0       1    DIO  data 1
 *	  4      0       2    DIO  data 2
 *	  5      0       3    DIO  data 3
 *	  6      0       4    DIO  data 4
 *	  7      0       5    DIO  data 5
 *	  8      0       6    DIO  data 6
 *	  9      0       7    DIO  data 7
 *	 10      1       3    DI   ack
 *	 11      1       4    DI   busy
 *	 12      1       2    DI   paper out
 *	 13      1       1    DI   select in
 *	 14      2       1    DO   auto LF
 *	 15      1       0    DI   error
 *	 16      2       2    DO   init
 *	 17      2       3    DO   select printer
 *	18-25                      ground
 *
 * When an IRQ is configured subdevice 3 pretends to be a digital
 * input subdevice, but it always returns 0 when read. However, if
 * you run a command with scan_begin_src=TRIG_EXT, it uses pin 10
 * as a external trigger, which can be used to wake up tasks.
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/comedi/comedidev.h>

/*
 * Register map
 */
#define PARPORT_DATA_REG …
#define PARPORT_STATUS_REG …
#define PARPORT_CTRL_REG …
#define PARPORT_CTRL_IRQ_ENA …
#define PARPORT_CTRL_BIDIR_ENA …

static int parport_data_reg_insn_bits(struct comedi_device *dev,
				      struct comedi_subdevice *s,
				      struct comedi_insn *insn,
				      unsigned int *data)
{ … }

static int parport_data_reg_insn_config(struct comedi_device *dev,
					struct comedi_subdevice *s,
					struct comedi_insn *insn,
					unsigned int *data)
{ … }

static int parport_status_reg_insn_bits(struct comedi_device *dev,
					struct comedi_subdevice *s,
					struct comedi_insn *insn,
					unsigned int *data)
{ … }

static int parport_ctrl_reg_insn_bits(struct comedi_device *dev,
				      struct comedi_subdevice *s,
				      struct comedi_insn *insn,
				      unsigned int *data)
{ … }

static int parport_intr_insn_bits(struct comedi_device *dev,
				  struct comedi_subdevice *s,
				  struct comedi_insn *insn,
				  unsigned int *data)
{ … }

static int parport_intr_cmdtest(struct comedi_device *dev,
				struct comedi_subdevice *s,
				struct comedi_cmd *cmd)
{ … }

static int parport_intr_cmd(struct comedi_device *dev,
			    struct comedi_subdevice *s)
{ … }

static int parport_intr_cancel(struct comedi_device *dev,
			       struct comedi_subdevice *s)
{ … }

static irqreturn_t parport_interrupt(int irq, void *d)
{ … }

static int parport_attach(struct comedi_device *dev,
			  struct comedi_devconfig *it)
{ … }

static struct comedi_driver parport_driver = …;
module_comedi_driver(…);

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;