dt2817.c

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/*
    comedi/drivers/dt2817.c
    Hardware driver for Data Translation DT2817

    COMEDI - Linux Control and Measurement Device Interface
    Copyright (C) 1998 David A. Schleef <[email protected]>

    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_dio_insn_config(struct comedi_device *dev,
                  struct comedi_subdevice *s,
                  struct comedi_insn *insn, unsigned int *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(struct comedi_device *dev,
                struct comedi_subdevice *s,
                struct comedi_insn *insn, unsigned int *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 insn->n;
}

static int dt2817_attach(struct comedi_device *dev, struct comedi_devconfig *it)
{
    int ret;
    struct comedi_subdevice *s;
    unsigned long iobase;

    iobase = it->options[0];
    printk(KERN_INFO "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";

    ret = comedi_alloc_subdevices(dev, 1);
    if (ret)
        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(KERN_INFO "\n");

    return 0;
}

static void dt2817_detach(struct comedi_device *dev)
{
    if (dev->iobase)
        release_region(dev->iobase, DT2817_SIZE);
}

static struct comedi_driver dt2817_driver = {
    .driver_name    = "dt2817",
    .module     = THIS_MODULE,
    .attach     = dt2817_attach,
    .detach     = dt2817_detach,
};
module_comedi_driver(dt2817_driver);

MODULE_AUTHOR("Comedi http://www.comedi.org");
MODULE_DESCRIPTION("Comedi low-level driver");
MODULE_LICENSE("GPL");