das6402.c

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/*
   Some comments on the code..

   - it shouldn't be necessary to use outb_p().

   - ignoreirq creates a race condition.  It needs to be fixed.

 */

/*
   comedi/drivers/das6402.c
   An experimental driver for Computerboards' DAS6402 I/O card

   Copyright (C) 1999 Oystein Svendsen <[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: das6402
Description: Keithley Metrabyte DAS6402 (& compatibles)
Author: Oystein Svendsen <[email protected]>
Status: bitrotten
Devices: [Keithley Metrabyte] DAS6402 (das6402)

This driver has suffered bitrot.
*/

#include <linux/interrupt.h>
#include "../comedidev.h"

#include <linux/ioport.h>

#define DAS6402_SIZE 16

#define N_WORDS (3000*64)

#define STOP    0
#define START   1

#define SCANL 0x3f00
#define BYTE unsigned char
#define WORD unsigned short

/*----- register 8 ----*/
#define CLRINT 0x01
#define CLRXTR 0x02
#define CLRXIN 0x04
#define EXTEND 0x10
#define ARMED 0x20      /* enable conting of post sample conv */
#define POSTMODE 0x40
#define MHZ 0x80        /* 10 MHz clock */
/*---------------------*/

/*----- register 9 ----*/
#define IRQ (0x04 << 4)     /* these two are                         */
#define IRQV 10         /*               dependent on each other */

#define CONVSRC 0x03        /* trig src is Intarnal pacer */
#define BURSTEN 0x04        /* enable burst */
#define XINTE 0x08      /* use external int. trig */
#define INTE 0x80       /* enable analog interrupts */
/*---------------------*/

/*----- register 10 ---*/
#define TGEN 0x01       /* Use pin DI1 for externl trigging? */
#define TGSEL 0x02      /* Use edge triggering */
#define TGPOL 0x04      /* active edge is falling */
#define PRETRIG 0x08        /* pretrig */
/*---------------------*/

/*----- register 11 ---*/
#define EOB 0x0c
#define FIFOHFULL 0x08
#define GAIN 0x01
#define FIFONEPTY 0x04
#define MODE 0x10
#define SEM 0x20
#define BIP 0x40
/*---------------------*/

#define M0 0x00
#define M2 0x04

#define C0 0x00
#define C1 0x40
#define C2 0x80
#define RWLH 0x30

struct das6402_private {
    int ai_bytes_to_read;

    int das6402_ignoreirq;
};
#define devpriv ((struct das6402_private *)dev->private)

static void das6402_ai_fifo_dregs(struct comedi_device *dev,
                  struct comedi_subdevice *s)
{
    while (1) {
        if (!(inb(dev->iobase + 8) & 0x01))
            return;
        comedi_buf_put(s->async, inw(dev->iobase));
    }
}

static void das6402_setcounter(struct comedi_device *dev)
{
    BYTE p;
    unsigned short ctrlwrd;

    /* set up counter0 first, mode 0 */
    p = M0 | C0 | RWLH;
    outb_p(p, dev->iobase + 15);
    ctrlwrd = 2000;
    p = (BYTE) (0xff & ctrlwrd);
    outb_p(p, dev->iobase + 12);
    p = (BYTE) (0xff & (ctrlwrd >> 8));
    outb_p(p, dev->iobase + 12);

    /* set up counter1, mode 2 */
    p = M2 | C1 | RWLH;
    outb_p(p, dev->iobase + 15);
    ctrlwrd = 10;
    p = (BYTE) (0xff & ctrlwrd);
    outb_p(p, dev->iobase + 13);
    p = (BYTE) (0xff & (ctrlwrd >> 8));
    outb_p(p, dev->iobase + 13);

    /* set up counter1, mode 2 */
    p = M2 | C2 | RWLH;
    outb_p(p, dev->iobase + 15);
    ctrlwrd = 1000;
    p = (BYTE) (0xff & ctrlwrd);
    outb_p(p, dev->iobase + 14);
    p = (BYTE) (0xff & (ctrlwrd >> 8));
    outb_p(p, dev->iobase + 14);
}

static irqreturn_t intr_handler(int irq, void *d)
{
    struct comedi_device *dev = d;
    struct comedi_subdevice *s = &dev->subdevices[0];

    if (!dev->attached || devpriv->das6402_ignoreirq) {
        dev_warn(dev->class_dev, "BUG: spurious interrupt\n");
        return IRQ_HANDLED;
    }
#ifdef DEBUG
    printk("das6402: interrupt! das6402_irqcount=%i\n",
           devpriv->das6402_irqcount);
    printk("das6402: iobase+2=%i\n", inw_p(dev->iobase + 2));
#endif

    das6402_ai_fifo_dregs(dev, s);

    if (s->async->buf_write_count >= devpriv->ai_bytes_to_read) {
        outw_p(SCANL, dev->iobase + 2); /* clears the fifo */
        outb(0x07, dev->iobase + 8);    /* clears all flip-flops */
#ifdef DEBUG
        printk("das6402: Got %i samples\n\n",
               devpriv->das6402_wordsread - diff);
#endif
        s->async->events |= COMEDI_CB_EOA;
        comedi_event(dev, s);
    }

    outb(0x01, dev->iobase + 8);    /* clear only the interrupt flip-flop */

    comedi_event(dev, s);
    return IRQ_HANDLED;
}

#if 0
static void das6402_ai_fifo_read(struct comedi_device *dev, short *data, int n)
{
    int i;

    for (i = 0; i < n; i++)
        data[i] = inw(dev->iobase);
}
#endif

static int das6402_ai_cancel(struct comedi_device *dev,
                 struct comedi_subdevice *s)
{
    /*
     *  This function should reset the board from whatever condition it
     *  is in (i.e., acquiring data), to a non-active state.
     */

    devpriv->das6402_ignoreirq = 1;
    dev_dbg(dev->class_dev, "Stopping acquisition\n");
    devpriv->das6402_ignoreirq = 1;
    outb_p(0x02, dev->iobase + 10); /* disable external trigging */
    outw_p(SCANL, dev->iobase + 2); /* resets the card fifo */
    outb_p(0, dev->iobase + 9); /* disables interrupts */

    outw_p(SCANL, dev->iobase + 2);

    return 0;
}

#ifdef unused
static int das6402_ai_mode2(struct comedi_device *dev,
                struct comedi_subdevice *s, comedi_trig * it)
{
    devpriv->das6402_ignoreirq = 1;
    dev_dbg(dev->class_dev, "Starting acquisition\n");
    outb_p(0x03, dev->iobase + 10); /* enable external trigging */
    outw_p(SCANL, dev->iobase + 2); /* resets the card fifo */
    outb_p(IRQ | CONVSRC | BURSTEN | INTE, dev->iobase + 9);

    devpriv->ai_bytes_to_read = it->n * sizeof(short);

    /* um... ignoreirq is a nasty race condition */
    devpriv->das6402_ignoreirq = 0;

    outw_p(SCANL, dev->iobase + 2);

    return 0;
}
#endif

static int board_init(struct comedi_device *dev)
{
    BYTE b;

    devpriv->das6402_ignoreirq = 1;

    outb(0x07, dev->iobase + 8);

    /* register 11  */
    outb_p(MODE, dev->iobase + 11);
    b = BIP | SEM | MODE | GAIN | FIFOHFULL;
    outb_p(b, dev->iobase + 11);

    /* register 8   */
    outb_p(EXTEND, dev->iobase + 8);
    b = EXTEND | MHZ;
    outb_p(b, dev->iobase + 8);
    b = MHZ | CLRINT | CLRXTR | CLRXIN;
    outb_p(b, dev->iobase + 8);

    /* register 9    */
    b = IRQ | CONVSRC | BURSTEN | INTE;
    outb_p(b, dev->iobase + 9);

    /* register 10   */
    b = TGSEL | TGEN;
    outb_p(b, dev->iobase + 10);

    b = 0x07;
    outb_p(b, dev->iobase + 8);

    das6402_setcounter(dev);

    outw_p(SCANL, dev->iobase + 2); /* reset card fifo */

    devpriv->das6402_ignoreirq = 0;

    return 0;
}

static int das6402_attach(struct comedi_device *dev,
              struct comedi_devconfig *it)
{
    unsigned int irq;
    unsigned long iobase;
    int ret;
    struct comedi_subdevice *s;

    dev->board_name = "das6402";

    iobase = it->options[0];
    if (iobase == 0)
        iobase = 0x300;

    if (!request_region(iobase, DAS6402_SIZE, "das6402")) {
        dev_err(dev->class_dev, "I/O port conflict\n");
        return -EIO;
    }
    dev->iobase = iobase;

    /* should do a probe here */

    irq = it->options[0];
    dev_dbg(dev->class_dev, "( irq = %u )\n", irq);
    ret = request_irq(irq, intr_handler, 0, "das6402", dev);
    if (ret < 0)
        return ret;

    dev->irq = irq;
    ret = alloc_private(dev, sizeof(struct das6402_private));
    if (ret < 0)
        return ret;

    ret = comedi_alloc_subdevices(dev, 1);
    if (ret)
        return ret;

    /* ai subdevice */
    s = &dev->subdevices[0];
    s->type = COMEDI_SUBD_AI;
    s->subdev_flags = SDF_READABLE | SDF_GROUND;
    s->n_chan = 8;
    /* s->trig[2]=das6402_ai_mode2; */
    s->cancel = das6402_ai_cancel;
    s->maxdata = (1 << 12) - 1;
    s->len_chanlist = 16;   /* ? */
    s->range_table = &range_unknown;

    board_init(dev);

    return 0;
}

static void das6402_detach(struct comedi_device *dev)
{
    if (dev->irq)
        free_irq(dev->irq, dev);
    if (dev->iobase)
        release_region(dev->iobase, DAS6402_SIZE);
}

static struct comedi_driver das6402_driver = {
    .driver_name    = "das6402",
    .module     = THIS_MODULE,
    .attach     = das6402_attach,
    .detach     = das6402_detach,
};
module_comedi_driver(das6402_driver)

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