Staging: comedi: add dt2817 driver

/*

    comedi/drivers/dt2817.c

    Hardware driver for Data Translation DT2817

    COMEDI - Linux Control and Measurement Device Interface

    Copyright (C) 1998 David A. Schleef <ds@schleef.org>

    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation; either version 2 of the License, or

    (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with this program; if not, write to the Free Software

    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

/*

Driver: dt2817

Description: Data Translation DT2817

Author: ds

Status: complete

Devices: [Data Translation] DT2817 (dt2817)

A very simple digital I/O card.  Four banks of 8 lines, each bank

is configurable for input or output.  One wonders why it takes a

50 page manual to describe this thing.

The driver (which, btw, is much less than 50 pages) has 1 subdevice

with 32 channels, configurable in groups of 8.

Configuration options:

  [0] - I/O port base base address

*/

#include "../comedidev.h"

#include <linux/ioport.h>

#define DT2817_SIZE 5

#define DT2817_CR 0

#define DT2817_DATA 1

static int dt2817_attach(comedi_device * dev, comedi_devconfig * it);

static int dt2817_detach(comedi_device * dev);

static comedi_driver driver_dt2817 = {

      driver_name:"dt2817",

      module:THIS_MODULE,

      attach:dt2817_attach,

      detach:dt2817_detach,

};

COMEDI_INITCLEANUP(driver_dt2817);

static int dt2817_dio_insn_config(comedi_device * dev, comedi_subdevice * s,

	comedi_insn * insn, lsampl_t * data)

{

	int mask;

	int chan;

	int oe = 0;

	if (insn->n != 1)

		return -EINVAL;

	chan = CR_CHAN(insn->chanspec);

	if (chan < 8) {

		mask = 0xff;

	} else if (chan < 16) {

		mask = 0xff00;

	} else if (chan < 24) {

		mask = 0xff0000;

	} else

		mask = 0xff000000;

	if (data[0])

		s->io_bits |= mask;

	else

		s->io_bits &= ~mask;

	if (s->io_bits & 0x000000ff)

		oe |= 0x1;

	if (s->io_bits & 0x0000ff00)

		oe |= 0x2;

	if (s->io_bits & 0x00ff0000)

		oe |= 0x4;

	if (s->io_bits & 0xff000000)

		oe |= 0x8;

	outb(oe, dev->iobase + DT2817_CR);

	return 1;

}

static int dt2817_dio_insn_bits(comedi_device * dev, comedi_subdevice * s,

	comedi_insn * insn, lsampl_t * data)

{

	unsigned int changed;

	/* It's questionable whether it is more important in

	 * a driver like this to be deterministic or fast.

	 * We choose fast. */

	if (data[0]) {

		changed = s->state;

		s->state &= ~data[0];

		s->state |= (data[0] & data[1]);

		changed ^= s->state;

		changed &= s->io_bits;

		if (changed & 0x000000ff)

			outb(s->state & 0xff, dev->iobase + DT2817_DATA + 0);

		if (changed & 0x0000ff00)

			outb((s->state >> 8) & 0xff,

				dev->iobase + DT2817_DATA + 1);

		if (changed & 0x00ff0000)

			outb((s->state >> 16) & 0xff,

				dev->iobase + DT2817_DATA + 2);

		if (changed & 0xff000000)

			outb((s->state >> 24) & 0xff,

				dev->iobase + DT2817_DATA + 3);

	}

	data[1] = inb(dev->iobase + DT2817_DATA + 0);

	data[1] |= (inb(dev->iobase + DT2817_DATA + 1) << 8);

	data[1] |= (inb(dev->iobase + DT2817_DATA + 2) << 16);

	data[1] |= (inb(dev->iobase + DT2817_DATA + 3) << 24);

	return 2;

}

static int dt2817_attach(comedi_device * dev, comedi_devconfig * it)

{

	int ret;

	comedi_subdevice *s;

	unsigned long iobase;

	iobase = it->options[0];

	printk("comedi%d: dt2817: 0x%04lx ", dev->minor, iobase);

	if (!request_region(iobase, DT2817_SIZE, "dt2817")) {

		printk("I/O port conflict\n");

		return -EIO;

	}

	dev->iobase = iobase;

	dev->board_name = "dt2817";

	if ((ret = alloc_subdevices(dev, 1)) < 0)

		return ret;

	s = dev->subdevices + 0;

	s->n_chan = 32;

	s->type = COMEDI_SUBD_DIO;

	s->subdev_flags = SDF_READABLE | SDF_WRITABLE;

	s->range_table = &range_digital;

	s->maxdata = 1;

	s->insn_bits = dt2817_dio_insn_bits;

	s->insn_config = dt2817_dio_insn_config;

	s->state = 0;

	outb(0, dev->iobase + DT2817_CR);

	printk("\n");

	return 0;

}

static int dt2817_detach(comedi_device * dev)

{

	printk("comedi%d: dt2817: remove\n", dev->minor);

	if (dev->iobase)

		release_region(dev->iobase, DT2817_SIZE);

	return 0;

}