// 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 <ds@schleef.org>
*/
/*
* 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 0x00
#define PARPORT_STATUS_REG 0x01
#define PARPORT_CTRL_REG 0x02
#define PARPORT_CTRL_IRQ_ENA BIT(4)
#define PARPORT_CTRL_BIDIR_ENA BIT(5)
static int parport_data_reg_insn_bits(
struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
unsigned int *data)
{
if (comedi_dio_update_state(s, data))
outb(s->state, dev->iobase + PARPORT_DATA_REG);
data[1] = inb(dev->iobase + PARPORT_DATA_REG);
return insn->n;
}
static int parport_data_reg_insn_config(
struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
unsigned int *data)
{
unsigned int ctrl;
int ret;
ret = comedi_dio_insn_config(dev, s, insn, data, 0xff);
if (ret)
return ret;
ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
if (s->io_bits)
ctrl &= ~PARPORT_CTRL_BIDIR_ENA;
else
ctrl |= PARPORT_CTRL_BIDIR_ENA;
outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
return insn->n;
}
static int parport_status_reg_insn_bits(
struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
unsigned int *data)
{
data[1] = inb(dev->iobase + PARPORT_STATUS_REG) >> 3;
return insn->n;
}
static int parport_ctrl_reg_insn_bits(
struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
unsigned int *data)
{
unsigned int ctrl;
if (comedi_dio_update_state(s, data)) {
ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
ctrl &= (PARPORT_CTRL_IRQ_ENA | PARPORT_CTRL_BIDIR_ENA);
ctrl |= s->state;
outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
}
data[1] = s->state;
return insn->n;
}
static int parport_intr_insn_bits(
struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
unsigned int *data)
{
data[1] = 0;
return insn->n;
}
static int parport_intr_cmdtest(
struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_cmd *cmd)
{
int err = 0;
/* Step 1 : check if triggers are trivially valid */
err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW);
err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_NONE);
if (err)
return 1;
/* Step 2a : make sure trigger sources are unique */
/* Step 2b : and mutually compatible */
/* Step 3: check if arguments are trivially valid */
err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
err |= comedi_check_trigger_arg_is(&cmd->convert_arg, 0);
err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
cmd->chanlist_len);
err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);
if (err)
return 3;
/* Step 4: fix up any arguments */
/* Step 5: check channel list if it exists */
return 0;
}
static int parport_intr_cmd(
struct comedi_device *dev,
struct comedi_subdevice *s)
{
unsigned int ctrl;
ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
ctrl |= PARPORT_CTRL_IRQ_ENA;
outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
return 0;
}
static int parport_intr_cancel(
struct comedi_device *dev,
struct comedi_subdevice *s)
{
unsigned int ctrl;
ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
ctrl &= ~PARPORT_CTRL_IRQ_ENA;
outb(ctrl, dev->iobase + PARPORT_CTRL_REG);
return 0;
}
static irqreturn_t parport_interrupt(
int irq,
void *d)
{
struct comedi_device *dev = d;
struct comedi_subdevice *s = dev->read_subdev;
unsigned int ctrl;
unsigned short val = 0;
ctrl = inb(dev->iobase + PARPORT_CTRL_REG);
if (!(ctrl & PARPORT_CTRL_IRQ_ENA))
return IRQ_NONE;
comedi_buf_write_samples(s, &val, 1);
comedi_handle_events(dev, s);
return IRQ_HANDLED;
}
static int parport_attach(
struct comedi_device *dev,
struct comedi_devconfig *it)
{
struct comedi_subdevice *s;
int ret;
ret = comedi_request_region(dev, it->options[0], 0x03);
if (ret)
return ret;
if (it->options[1]) {
ret = request_irq(it->options[1], parport_interrupt, 0,
dev->board_name, dev);
if (ret == 0)
dev->irq = it->options[1];
}
ret = comedi_alloc_subdevices(dev, dev->irq ? 4 : 3);
if (ret)
return ret;
/* Digial I/O subdevice - Parallel port DATA register */
s = &dev->subdevices[0];
s->type = COMEDI_SUBD_DIO;
s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
s->n_chan = 8;
s->maxdata = 1;
s->range_table = &range_digital;
s->insn_bits = parport_data_reg_insn_bits;
s->insn_config = parport_data_reg_insn_config;
/* Digial Input subdevice - Parallel port STATUS register */
s = &dev->subdevices[1];
s->type = COMEDI_SUBD_DI;
s->subdev_flags = SDF_READABLE;
s->n_chan = 5;
s->maxdata = 1;
s->range_table = &range_digital;
s->insn_bits = parport_status_reg_insn_bits;
/* Digial Output subdevice - Parallel port CONTROL register */
s = &dev->subdevices[2];
s->type = COMEDI_SUBD_DO;
s->subdev_flags = SDF_WRITABLE;
s->n_chan = 4;
s->maxdata = 1;
s->range_table = &range_digital;
s->insn_bits = parport_ctrl_reg_insn_bits;
if (dev->irq) {
/* Digial Input subdevice - Interrupt support */
s = &dev->subdevices[3];
dev->read_subdev = s;
s->type = COMEDI_SUBD_DI;
s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
s->n_chan = 1;
s->maxdata = 1;
s->range_table = &range_digital;
s->insn_bits = parport_intr_insn_bits;
s->len_chanlist = 1;
s->do_cmdtest = parport_intr_cmdtest;
s->do_cmd = parport_intr_cmd;
s->cancel = parport_intr_cancel;
}
outb(0, dev->iobase + PARPORT_DATA_REG);
outb(0, dev->iobase + PARPORT_CTRL_REG);
return 0;
}
static struct comedi_driver parport_driver = {
.driver_name =
"comedi_parport",
.module = THIS_MODULE,
.attach = parport_attach,
.detach = comedi_legacy_detach,
};
module_comedi_driver(parport_driver);
MODULE_AUTHOR(
"Comedi https://www.comedi.org");
MODULE_DESCRIPTION(
"Comedi: Standard parallel port driver");
MODULE_LICENSE(
"GPL");
