/*======================================================================

    comedi/drivers/quatech_daqp_cs.c

    Quatech DAQP PCMCIA data capture cards COMEDI client driver
    Copyright (C) 2000, 2003 Brent Baccala <baccala@freesoft.org>
    The DAQP interface code in this file is released into the public domain.

    COMEDI - Linux Control and Measurement Device Interface
    Copyright (C) 1998 David A. Schleef <ds@schleef.org>
    http://www.comedi.org/

    quatech_daqp_cs.c 1.10

    Documentation for the DAQP PCMCIA cards can be found on Quatech's site:

                ftp://ftp.quatech.com/Manuals/daqp-208.pdf

    This manual is for both the DAQP-208 and the DAQP-308.

    What works:

        - A/D conversion
            - 8 channels
            - 4 gain ranges
            - ground ref or differential
            - single-shot and timed both supported
        - D/A conversion, single-shot
        - digital I/O

    What doesn't:

        - any kind of triggering - external or D/A channel 1
        - the card's optional expansion board
        - the card's timer (for anything other than A/D conversion)
        - D/A update modes other than immediate (i.e, timed)
        - fancier timing modes
        - setting card's FIFO buffer thresholds to anything but default

======================================================================*/

/*
Driver: quatech_daqp_cs
Description: Quatech DAQP PCMCIA data capture cards
Author: Brent Baccala <baccala@freesoft.org>
Status: works
Devices: [Quatech] DAQP-208 (daqp), DAQP-308
*/

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

#include <pcmcia/cistpl.h>
#include <pcmcia/cisreg.h>
#include <pcmcia/ds.h>

#include <linux/completion.h>

#include "comedi_fc.h"

struct daqp_private {
        int stop;

        enum { semaphore, buffer } interrupt_mode;

        struct completion eos;

        int count;
};

/* The DAQP communicates with the system through a 16 byte I/O window. */

#define DAQP_FIFO_SIZE          4096

#define DAQP_FIFO               0
#define DAQP_SCANLIST           1
#define DAQP_CONTROL            2
#define DAQP_STATUS             2
#define DAQP_DIGITAL_IO         3
#define DAQP_PACER_LOW          4
#define DAQP_PACER_MID          5
#define DAQP_PACER_HIGH         6
#define DAQP_COMMAND            7
#define DAQP_DA                 8
#define DAQP_TIMER              10
#define DAQP_AUX                15

#define DAQP_SCANLIST_DIFFERENTIAL      0x4000
#define DAQP_SCANLIST_GAIN(x)           ((x)<<12)
#define DAQP_SCANLIST_CHANNEL(x)        ((x)<<8)
#define DAQP_SCANLIST_START             0x0080
#define DAQP_SCANLIST_EXT_GAIN(x)       ((x)<<4)
#define DAQP_SCANLIST_EXT_CHANNEL(x)    (x)

#define DAQP_CONTROL_PACER_100kHz       0xc0
#define DAQP_CONTROL_PACER_1MHz         0x80
#define DAQP_CONTROL_PACER_5MHz         0x40
#define DAQP_CONTROL_PACER_EXTERNAL     0x00
#define DAQP_CONTORL_EXPANSION          0x20
#define DAQP_CONTROL_EOS_INT_ENABLE     0x10
#define DAQP_CONTROL_FIFO_INT_ENABLE    0x08
#define DAQP_CONTROL_TRIGGER_ONESHOT    0x00
#define DAQP_CONTROL_TRIGGER_CONTINUOUS 0x04
#define DAQP_CONTROL_TRIGGER_INTERNAL   0x00
#define DAQP_CONTROL_TRIGGER_EXTERNAL   0x02
#define DAQP_CONTROL_TRIGGER_RISING     0x00
#define DAQP_CONTROL_TRIGGER_FALLING    0x01

#define DAQP_STATUS_IDLE                0x80
#define DAQP_STATUS_RUNNING             0x40
#define DAQP_STATUS_EVENTS              0x38
#define DAQP_STATUS_DATA_LOST           0x20
#define DAQP_STATUS_END_OF_SCAN         0x10
#define DAQP_STATUS_FIFO_THRESHOLD      0x08
#define DAQP_STATUS_FIFO_FULL           0x04
#define DAQP_STATUS_FIFO_NEARFULL       0x02
#define DAQP_STATUS_FIFO_EMPTY          0x01

#define DAQP_COMMAND_ARM                0x80
#define DAQP_COMMAND_RSTF               0x40
#define DAQP_COMMAND_RSTQ               0x20
#define DAQP_COMMAND_STOP               0x10
#define DAQP_COMMAND_LATCH              0x08
#define DAQP_COMMAND_100kHz             0x00
#define DAQP_COMMAND_50kHz              0x02
#define DAQP_COMMAND_25kHz              0x04
#define DAQP_COMMAND_FIFO_DATA          0x01
#define DAQP_COMMAND_FIFO_PROGRAM       0x00

#define DAQP_AUX_TRIGGER_TTL            0x00
#define DAQP_AUX_TRIGGER_ANALOG         0x80
#define DAQP_AUX_TRIGGER_PRETRIGGER     0x40
#define DAQP_AUX_TIMER_INT_ENABLE       0x20
#define DAQP_AUX_TIMER_RELOAD           0x00
#define DAQP_AUX_TIMER_PAUSE            0x08
#define DAQP_AUX_TIMER_GO               0x10
#define DAQP_AUX_TIMER_GO_EXTERNAL      0x18
#define DAQP_AUX_TIMER_EXTERNAL_SRC     0x04
#define DAQP_AUX_TIMER_INTERNAL_SRC     0x00
#define DAQP_AUX_DA_DIRECT              0x00
#define DAQP_AUX_DA_OVERFLOW            0x01
#define DAQP_AUX_DA_EXTERNAL            0x02
#define DAQP_AUX_DA_PACER               0x03

#define DAQP_AUX_RUNNING                0x80
#define DAQP_AUX_TRIGGERED              0x40
#define DAQP_AUX_DA_BUFFER              0x20
#define DAQP_AUX_TIMER_OVERFLOW         0x10
#define DAQP_AUX_CONVERSION             0x08
#define DAQP_AUX_DATA_LOST              0x04
#define DAQP_AUX_FIFO_NEARFULL          0x02
#define DAQP_AUX_FIFO_EMPTY             0x01

static const struct comedi_lrange range_daqp_ai = {
        4, {
                BIP_RANGE(10),
                BIP_RANGE(5),
                BIP_RANGE(2.5),
                BIP_RANGE(1.25)
        }
};

/* Cancel a running acquisition */

static int daqp_ai_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
{
        struct daqp_private *devpriv = dev->private;

        if (devpriv->stop)
                return -EIO;

        outb(DAQP_COMMAND_STOP, dev->iobase + DAQP_COMMAND);

        /* flush any linguring data in FIFO - superfluous here */
        /* outb(DAQP_COMMAND_RSTF, dev->iobase+DAQP_COMMAND); */

        devpriv->interrupt_mode = semaphore;

        return 0;
}

/* Interrupt handler
 *
 * Operates in one of two modes.  If devpriv->interrupt_mode is
 * 'semaphore', just signal the devpriv->eos completion and return
 * (one-shot mode).  Otherwise (continuous mode), read data in from
 * the card, transfer it to the buffer provided by the higher-level
 * comedi kernel module, and signal various comedi callback routines,
 * which run pretty quick.
 */
static enum irqreturn daqp_interrupt(int irq, void *dev_id)
{
        struct comedi_device *dev = dev_id;
        struct daqp_private *devpriv = dev->private;
        struct comedi_subdevice *s = dev->read_subdev;
        int loop_limit = 10000;
        int status;

        if (!dev->attached)
                return IRQ_NONE;

        switch (devpriv->interrupt_mode) {
        case semaphore:
                complete(&devpriv->eos);
                break;

        case buffer:
                while (!((status = inb(dev->iobase + DAQP_STATUS))
                         & DAQP_STATUS_FIFO_EMPTY)) {

                        short data;

                        if (status & DAQP_STATUS_DATA_LOST) {
                                s->async->events |=
                                    COMEDI_CB_EOA | COMEDI_CB_OVERFLOW;
                                dev_warn(dev->class_dev, "data lost\n");
                                daqp_ai_cancel(dev, s);
                                break;
                        }

                        data = inb(dev->iobase + DAQP_FIFO);
                        data |= inb(dev->iobase + DAQP_FIFO) << 8;
                        data ^= 0x8000;

                        comedi_buf_put(s->async, data);

                        /* If there's a limit, decrement it
                         * and stop conversion if zero
                         */

                        if (devpriv->count > 0) {
                                devpriv->count--;
                                if (devpriv->count == 0) {
                                        daqp_ai_cancel(dev, s);
                                        s->async->events |= COMEDI_CB_EOA;
                                        break;
                                }
                        }

                        if ((loop_limit--) <= 0)
                                break;
                }

                if (loop_limit <= 0) {
                        dev_warn(dev->class_dev,
                                 "loop_limit reached in daqp_interrupt()\n");
                        daqp_ai_cancel(dev, s);
                        s->async->events |= COMEDI_CB_EOA | COMEDI_CB_ERROR;
                }

                s->async->events |= COMEDI_CB_BLOCK;

                comedi_event(dev, s);
        }
        return IRQ_HANDLED;
}

static void daqp_ai_set_one_scanlist_entry(struct comedi_device *dev,
                                           unsigned int chanspec,
                                           int start)
{
        unsigned int chan = CR_CHAN(chanspec);
        unsigned int range = CR_RANGE(chanspec);
        unsigned int aref = CR_AREF(chanspec);
        unsigned int val;

        val = DAQP_SCANLIST_CHANNEL(chan) | DAQP_SCANLIST_GAIN(range);

        if (aref == AREF_DIFF)
                val |= DAQP_SCANLIST_DIFFERENTIAL;

        if (start)
                val |= DAQP_SCANLIST_START;

        outb(val & 0xff, dev->iobase + DAQP_SCANLIST);
        outb((val >> 8) & 0xff, dev->iobase + DAQP_SCANLIST);
}

/* One-shot analog data acquisition routine */

static int daqp_ai_insn_read(struct comedi_device *dev,
                             struct comedi_subdevice *s,
                             struct comedi_insn *insn, unsigned int *data)
{
        struct daqp_private *devpriv = dev->private;
        int i;
        int v;
        int counter = 10000;

        if (devpriv->stop)
                return -EIO;

        /* Stop any running conversion */
        daqp_ai_cancel(dev, s);

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

        /* Reset scan list queue */
        outb(DAQP_COMMAND_RSTQ, dev->iobase + DAQP_COMMAND);

        /* Program one scan list entry */
        daqp_ai_set_one_scanlist_entry(dev, insn->chanspec, 1);

        /* Reset data FIFO (see page 28 of DAQP User's Manual) */

        outb(DAQP_COMMAND_RSTF, dev->iobase + DAQP_COMMAND);

        /* Set trigger */

        v = DAQP_CONTROL_TRIGGER_ONESHOT | DAQP_CONTROL_TRIGGER_INTERNAL
            | DAQP_CONTROL_PACER_100kHz | DAQP_CONTROL_EOS_INT_ENABLE;

        outb(v, dev->iobase + DAQP_CONTROL);

        /* Reset any pending interrupts (my card has a tendency to require
         * require multiple reads on the status register to achieve this)
         */

        while (--counter
               && (inb(dev->iobase + DAQP_STATUS) & DAQP_STATUS_EVENTS))
                ;
        if (!counter) {
                dev_err(dev->class_dev,
                        "couldn't clear interrupts in status register\n");
                return -1;
        }

        init_completion(&devpriv->eos);
        devpriv->interrupt_mode = semaphore;

        for (i = 0; i < insn->n; i++) {

                /* Start conversion */
                outb(DAQP_COMMAND_ARM | DAQP_COMMAND_FIFO_DATA,
                     dev->iobase + DAQP_COMMAND);

                /* Wait for interrupt service routine to unblock completion */
                /* Maybe could use a timeout here, but it's interruptible */
                if (wait_for_completion_interruptible(&devpriv->eos))
                        return -EINTR;

                data[i] = inb(dev->iobase + DAQP_FIFO);
                data[i] |= inb(dev->iobase + DAQP_FIFO) << 8;
                data[i] ^= 0x8000;
        }

        return insn->n;
}

/* This function converts ns nanoseconds to a counter value suitable
 * for programming the device.  We always use the DAQP's 5 MHz clock,
 * which with its 24-bit counter, allows values up to 84 seconds.
 * Also, the function adjusts ns so that it cooresponds to the actual
 * time that the device will use.
 */

static int daqp_ns_to_timer(unsigned int *ns, int round)
{
        int timer;

        timer = *ns / 200;
        *ns = timer * 200;

        return timer;
}

/* cmdtest tests a particular command to see if it is valid.
 * Using the cmdtest ioctl, a user can create a valid cmd
 * and then have it executed by the cmd ioctl.
 *
 * cmdtest returns 1,2,3,4 or 0, depending on which tests
 * the command passes.
 */

static int daqp_ai_cmdtest(struct comedi_device *dev,
                           struct comedi_subdevice *s, struct comedi_cmd *cmd)
{
        int err = 0;
        int tmp;

        /* Step 1 : check if triggers are trivially valid */

        err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
        err |= cfc_check_trigger_src(&cmd->scan_begin_src,
                                        TRIG_TIMER | TRIG_FOLLOW);
        err |= cfc_check_trigger_src(&cmd->convert_src,
                                        TRIG_TIMER | TRIG_NOW);
        err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
        err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);

        if (err)
                return 1;

        /* Step 2a : make sure trigger sources are unique */

        err |= cfc_check_trigger_is_unique(cmd->scan_begin_src);
        err |= cfc_check_trigger_is_unique(cmd->convert_src);
        err |= cfc_check_trigger_is_unique(cmd->stop_src);

        /* Step 2b : and mutually compatible */

        if (err)
                return 2;

        /* Step 3: check if arguments are trivially valid */

        err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);

#define MAX_SPEED       10000   /* 100 kHz - in nanoseconds */

        if (cmd->scan_begin_src == TRIG_TIMER)
                err |= cfc_check_trigger_arg_min(&cmd->scan_begin_arg,
                                                 MAX_SPEED);

        /* If both scan_begin and convert are both timer values, the only
         * way that can make sense is if the scan time is the number of
         * conversions times the convert time
         */

        if (cmd->scan_begin_src == TRIG_TIMER && cmd->convert_src == TRIG_TIMER
            && cmd->scan_begin_arg != cmd->convert_arg * cmd->scan_end_arg) {
                err |= -EINVAL;
        }

        if (cmd->convert_src == TRIG_TIMER)
                err |= cfc_check_trigger_arg_min(&cmd->convert_arg, MAX_SPEED);

        err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);

        if (cmd->stop_src == TRIG_COUNT)
                err |= cfc_check_trigger_arg_max(&cmd->stop_arg, 0x00ffffff);
        else    /* TRIG_NONE */
                err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);

        if (err)
                return 3;

        /* step 4: fix up any arguments */

        if (cmd->scan_begin_src == TRIG_TIMER) {
                tmp = cmd->scan_begin_arg;
                daqp_ns_to_timer(&cmd->scan_begin_arg,
                                 cmd->flags & TRIG_ROUND_MASK);
                if (tmp != cmd->scan_begin_arg)
                        err++;
        }

        if (cmd->convert_src == TRIG_TIMER) {
                tmp = cmd->convert_arg;
                daqp_ns_to_timer(&cmd->convert_arg,
                                 cmd->flags & TRIG_ROUND_MASK);
                if (tmp != cmd->convert_arg)
                        err++;
        }

        if (err)
                return 4;

        return 0;
}

static int daqp_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
{
        struct daqp_private *devpriv = dev->private;
        struct comedi_cmd *cmd = &s->async->cmd;
        int counter;
        int scanlist_start_on_every_entry;
        int threshold;

        int i;
        int v;

        if (devpriv->stop)
                return -EIO;

        /* Stop any running conversion */
        daqp_ai_cancel(dev, s);

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

        /* Reset scan list queue */
        outb(DAQP_COMMAND_RSTQ, dev->iobase + DAQP_COMMAND);

        /* Program pacer clock
         *
         * There's two modes we can operate in.  If convert_src is
         * TRIG_TIMER, then convert_arg specifies the time between
         * each conversion, so we program the pacer clock to that
         * frequency and set the SCANLIST_START bit on every scanlist
         * entry.  Otherwise, convert_src is TRIG_NOW, which means
         * we want the fastest possible conversions, scan_begin_src
         * is TRIG_TIMER, and scan_begin_arg specifies the time between
         * each scan, so we program the pacer clock to this frequency
         * and only set the SCANLIST_START bit on the first entry.
         */

        if (cmd->convert_src == TRIG_TIMER) {
                counter = daqp_ns_to_timer(&cmd->convert_arg,
                                               cmd->flags & TRIG_ROUND_MASK);
                outb(counter & 0xff, dev->iobase + DAQP_PACER_LOW);
                outb((counter >> 8) & 0xff, dev->iobase + DAQP_PACER_MID);
                outb((counter >> 16) & 0xff, dev->iobase + DAQP_PACER_HIGH);
                scanlist_start_on_every_entry = 1;
        } else {
                counter = daqp_ns_to_timer(&cmd->scan_begin_arg,
                                               cmd->flags & TRIG_ROUND_MASK);
                outb(counter & 0xff, dev->iobase + DAQP_PACER_LOW);
                outb((counter >> 8) & 0xff, dev->iobase + DAQP_PACER_MID);
                outb((counter >> 16) & 0xff, dev->iobase + DAQP_PACER_HIGH);
                scanlist_start_on_every_entry = 0;
        }

        /* Program scan list */
        for (i = 0; i < cmd->chanlist_len; i++) {
                int start = (i == 0 || scanlist_start_on_every_entry);

                daqp_ai_set_one_scanlist_entry(dev, cmd->chanlist[i], start);
        }

        /* Now it's time to program the FIFO threshold, basically the
         * number of samples the card will buffer before it interrupts
         * the CPU.
         *
         * If we don't have a stop count, then use half the size of
         * the FIFO (the manufacturer's recommendation).  Consider
         * that the FIFO can hold 2K samples (4K bytes).  With the
         * threshold set at half the FIFO size, we have a margin of
         * error of 1024 samples.  At the chip's maximum sample rate
         * of 100,000 Hz, the CPU would have to delay interrupt
         * service for a full 10 milliseconds in order to lose data
         * here (as opposed to higher up in the kernel).  I've never
         * seen it happen.  However, for slow sample rates it may
         * buffer too much data and introduce too much delay for the
         * user application.
         *
         * If we have a stop count, then things get more interesting.
         * If the stop count is less than the FIFO size (actually
         * three-quarters of the FIFO size - see below), we just use
         * the stop count itself as the threshold, the card interrupts
         * us when that many samples have been taken, and we kill the
         * acquisition at that point and are done.  If the stop count
         * is larger than that, then we divide it by 2 until it's less
         * than three quarters of the FIFO size (we always leave the
         * top quarter of the FIFO as protection against sluggish CPU
         * interrupt response) and use that as the threshold.  So, if
         * the stop count is 4000 samples, we divide by two twice to
         * get 1000 samples, use that as the threshold, take four
         * interrupts to get our 4000 samples and are done.
         *
         * The algorithm could be more clever.  For example, if 81000
         * samples are requested, we could set the threshold to 1500
         * samples and take 54 interrupts to get 81000.  But 54 isn't
         * a power of two, so this algorithm won't find that option.
         * Instead, it'll set the threshold at 1266 and take 64
         * interrupts to get 81024 samples, of which the last 24 will
         * be discarded... but we won't get the last interrupt until
         * they've been collected.  To find the first option, the
         * computer could look at the prime decomposition of the
         * sample count (81000 = 3^4 * 5^3 * 2^3) and factor it into a
         * threshold (1500 = 3 * 5^3 * 2^2) and an interrupt count (54
         * = 3^3 * 2).  Hmmm... a one-line while loop or prime
         * decomposition of integers... I'll leave it the way it is.
         *
         * I'll also note a mini-race condition before ignoring it in
         * the code.  Let's say we're taking 4000 samples, as before.
         * After 1000 samples, we get an interrupt.  But before that
         * interrupt is completely serviced, another sample is taken
         * and loaded into the FIFO.  Since the interrupt handler
         * empties the FIFO before returning, it will read 1001 samples.
         * If that happens four times, we'll end up taking 4004 samples,
         * not 4000.  The interrupt handler will discard the extra four
         * samples (by halting the acquisition with four samples still
         * in the FIFO), but we will have to wait for them.
         *
         * In short, this code works pretty well, but for either of
         * the two reasons noted, might end up waiting for a few more
         * samples than actually requested.  Shouldn't make too much
         * of a difference.
         */

        /* Save away the number of conversions we should perform, and
         * compute the FIFO threshold (in bytes, not samples - that's
         * why we multiple devpriv->count by 2 = sizeof(sample))
         */

        if (cmd->stop_src == TRIG_COUNT) {
                devpriv->count = cmd->stop_arg * cmd->scan_end_arg;
                threshold = 2 * devpriv->count;
                while (threshold > DAQP_FIFO_SIZE * 3 / 4)
                        threshold /= 2;
        } else {
                devpriv->count = -1;
                threshold = DAQP_FIFO_SIZE / 2;
        }

        /* Reset data FIFO (see page 28 of DAQP User's Manual) */

        outb(DAQP_COMMAND_RSTF, dev->iobase + DAQP_COMMAND);

        /* Set FIFO threshold.  First two bytes are near-empty
         * threshold, which is unused; next two bytes are near-full
         * threshold.  We computed the number of bytes we want in the
         * FIFO when the interrupt is generated, what the card wants
         * is actually the number of available bytes left in the FIFO
         * when the interrupt is to happen.
         */

        outb(0x00, dev->iobase + DAQP_FIFO);
        outb(0x00, dev->iobase + DAQP_FIFO);

        outb((DAQP_FIFO_SIZE - threshold) & 0xff, dev->iobase + DAQP_FIFO);
        outb((DAQP_FIFO_SIZE - threshold) >> 8, dev->iobase + DAQP_FIFO);

        /* Set trigger */

        v = DAQP_CONTROL_TRIGGER_CONTINUOUS | DAQP_CONTROL_TRIGGER_INTERNAL
            | DAQP_CONTROL_PACER_5MHz | DAQP_CONTROL_FIFO_INT_ENABLE;

        outb(v, dev->iobase + DAQP_CONTROL);

        /* Reset any pending interrupts (my card has a tendency to require
         * require multiple reads on the status register to achieve this)
         */
        counter = 100;
        while (--counter
               && (inb(dev->iobase + DAQP_STATUS) & DAQP_STATUS_EVENTS))
                ;
        if (!counter) {
                dev_err(dev->class_dev,
                        "couldn't clear interrupts in status register\n");
                return -1;
        }

        devpriv->interrupt_mode = buffer;

        /* Start conversion */
        outb(DAQP_COMMAND_ARM | DAQP_COMMAND_FIFO_DATA,
             dev->iobase + DAQP_COMMAND);

        return 0;
}

static int daqp_ao_insn_write(struct comedi_device *dev,
                              struct comedi_subdevice *s,
                              struct comedi_insn *insn,
                              unsigned int *data)
{
        struct daqp_private *devpriv = dev->private;
        unsigned int chan = CR_CHAN(insn->chanspec);
        unsigned int val;
        int i;

        if (devpriv->stop)
                return -EIO;

        /* Make sure D/A update mode is direct update */
        outb(0, dev->iobase + DAQP_AUX);

        for (i = 0; i > insn->n; i++) {
                val = data[0];
                val &= 0x0fff;
                val ^= 0x0800;          /* Flip the sign */
                val |= (chan << 12);

                outw(val, dev->iobase + DAQP_DA);
        }

        return insn->n;
}

static int daqp_di_insn_bits(struct comedi_device *dev,
                             struct comedi_subdevice *s,
                             struct comedi_insn *insn,
                             unsigned int *data)
{
        struct daqp_private *devpriv = dev->private;

        if (devpriv->stop)
                return -EIO;

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

        return insn->n;
}

static int daqp_do_insn_bits(struct comedi_device *dev,
                             struct comedi_subdevice *s,
                             struct comedi_insn *insn,
                             unsigned int *data)
{
        struct daqp_private *devpriv = dev->private;
        unsigned int mask = data[0];
        unsigned int bits = data[1];

        if (devpriv->stop)
                return -EIO;

        if (mask) {
                s->state &= ~mask;
                s->state |= (bits & mask);

                outb(s->state, dev->iobase + DAQP_DIGITAL_IO);
        }

        data[1] = s->state;

        return insn->n;
}

static int daqp_auto_attach(struct comedi_device *dev,
                            unsigned long context)
{
        struct pcmcia_device *link = comedi_to_pcmcia_dev(dev);
        struct daqp_private *devpriv;
        struct comedi_subdevice *s;
        int ret;

        devpriv = kzalloc(sizeof(*devpriv), GFP_KERNEL);
        if (!devpriv)
                return -ENOMEM;
        dev->private = devpriv;

        link->config_flags |= CONF_AUTO_SET_IO | CONF_ENABLE_IRQ;
        ret = comedi_pcmcia_enable(dev, NULL);
        if (ret)
                return ret;
        dev->iobase = link->resource[0]->start;

        link->priv = dev;
        ret = pcmcia_request_irq(link, daqp_interrupt);
        if (ret)
                return ret;

        ret = comedi_alloc_subdevices(dev, 4);
        if (ret)
                return ret;

        s = &dev->subdevices[0];
        dev->read_subdev = s;
        s->type         = COMEDI_SUBD_AI;
        s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_DIFF | SDF_CMD_READ;
        s->n_chan       = 8;
        s->len_chanlist = 2048;
        s->maxdata      = 0xffff;
        s->range_table  = &range_daqp_ai;
        s->insn_read    = daqp_ai_insn_read;
        s->do_cmdtest   = daqp_ai_cmdtest;
        s->do_cmd       = daqp_ai_cmd;
        s->cancel       = daqp_ai_cancel;

        s = &dev->subdevices[1];
        s->type         = COMEDI_SUBD_AO;
        s->subdev_flags = SDF_WRITEABLE;
        s->n_chan       = 2;
        s->maxdata      = 0x0fff;
        s->range_table  = &range_bipolar5;
        s->insn_write   = daqp_ao_insn_write;

        s = &dev->subdevices[2];
        s->type         = COMEDI_SUBD_DI;
        s->subdev_flags = SDF_READABLE;
        s->n_chan       = 1;
        s->maxdata      = 1;
        s->insn_bits    = daqp_di_insn_bits;

        s = &dev->subdevices[3];
        s->type         = COMEDI_SUBD_DO;
        s->subdev_flags = SDF_WRITEABLE;
        s->n_chan       = 1;
        s->maxdata      = 1;
        s->insn_bits    = daqp_do_insn_bits;

        return 0;
}

static struct comedi_driver driver_daqp = {
        .driver_name    = "quatech_daqp_cs",
        .module         = THIS_MODULE,
        .auto_attach    = daqp_auto_attach,
        .detach         = comedi_pcmcia_disable,
};

static int daqp_cs_suspend(struct pcmcia_device *link)
{
        struct comedi_device *dev = link->priv;
        struct daqp_private *devpriv = dev ? dev->private : NULL;

        /* Mark the device as stopped, to block IO until later */
        if (devpriv)
                devpriv->stop = 1;

        return 0;
}

static int daqp_cs_resume(struct pcmcia_device *link)
{
        struct comedi_device *dev = link->priv;
        struct daqp_private *devpriv = dev ? dev->private : NULL;

        if (devpriv)
                devpriv->stop = 0;

        return 0;
}

static int daqp_cs_attach(struct pcmcia_device *link)
{
        return comedi_pcmcia_auto_config(link, &driver_daqp);
}

static const struct pcmcia_device_id daqp_cs_id_table[] = {
        PCMCIA_DEVICE_MANF_CARD(0x0137, 0x0027),
        PCMCIA_DEVICE_NULL
};
MODULE_DEVICE_TABLE(pcmcia, daqp_cs_id_table);

static struct pcmcia_driver daqp_cs_driver = {
        .name           = "quatech_daqp_cs",
        .owner          = THIS_MODULE,
        .id_table       = daqp_cs_id_table,
        .probe          = daqp_cs_attach,
        .remove         = comedi_pcmcia_auto_unconfig,
        .suspend        = daqp_cs_suspend,
        .resume         = daqp_cs_resume,
};
module_comedi_pcmcia_driver(driver_daqp, daqp_cs_driver);

MODULE_DESCRIPTION("Comedi driver for Quatech DAQP PCMCIA data capture cards");
MODULE_AUTHOR("Brent Baccala <baccala@freesoft.org>");
MODULE_LICENSE("GPL");