mtpav.c

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/*
 *      MOTU Midi Timepiece ALSA Main routines
 *      Copyright by Michael T. Mayers (c) Jan 09, 2000
 *      mail: [email protected]
 *      Thanks to John Galbraith
 *
 *      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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 *
 *      This driver is for the 'Mark Of The Unicorn' (MOTU)
 *      MidiTimePiece AV multiport MIDI interface 
 *
 *      IOPORTS
 *      -------
 *      8 MIDI Ins and 8 MIDI outs
 *      Video Sync In (BNC), Word Sync Out (BNC), 
 *      ADAT Sync Out (DB9)
 *      SMPTE in/out (1/4")
 *      2 programmable pedal/footswitch inputs and 4 programmable MIDI controller knobs.
 *      Macintosh RS422 serial port
 *      RS422 "network" port for ganging multiple MTP's
 *      PC Parallel Port ( which this driver currently uses )
 *
 *      MISC FEATURES
 *      -------------
 *      Hardware MIDI routing, merging, and filtering   
 *      MIDI Synchronization to Video, ADAT, SMPTE and other Clock sources
 *      128 'scene' memories, recallable from MIDI program change
 *
 *
 * ChangeLog
 * Jun 11 2001  Takashi Iwai <[email protected]>
 *      - Recoded & debugged
 *      - Added timer interrupt for midi outputs
 *      - hwports is between 1 and 8, which specifies the number of hardware ports.
 *        The three global ports, computer, adat and broadcast ports, are created
 *        always after h/w and remote ports.
 *
 */

#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/moduleparam.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/rawmidi.h>
#include <linux/delay.h>

/*
 *      globals
 */
MODULE_AUTHOR("Michael T. Mayers");
MODULE_DESCRIPTION("MOTU MidiTimePiece AV multiport MIDI");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{MOTU,MidiTimePiece AV multiport MIDI}}");

// io resources
#define MTPAV_IOBASE        0x378
#define MTPAV_IRQ       7
#define MTPAV_MAX_PORTS     8

static int index = SNDRV_DEFAULT_IDX1;
static char *id = SNDRV_DEFAULT_STR1;
static long port = MTPAV_IOBASE;    /* 0x378, 0x278 */
static int irq = MTPAV_IRQ;     /* 7, 5 */
static int hwports = MTPAV_MAX_PORTS;   /* use hardware ports 1-8 */

module_param(index, int, 0444);
MODULE_PARM_DESC(index, "Index value for MotuMTPAV MIDI.");
module_param(id, charp, 0444);
MODULE_PARM_DESC(id, "ID string for MotuMTPAV MIDI.");
module_param(port, long, 0444);
MODULE_PARM_DESC(port, "Parallel port # for MotuMTPAV MIDI.");
module_param(irq, int, 0444);
MODULE_PARM_DESC(irq, "Parallel IRQ # for MotuMTPAV MIDI.");
module_param(hwports, int, 0444);
MODULE_PARM_DESC(hwports, "Hardware ports # for MotuMTPAV MIDI.");

static struct platform_device *device;

/*
 *      defines
 */
//#define USE_FAKE_MTP //       don't actually read/write to MTP device (for debugging without an actual unit) (does not work yet)

// parallel port usage masks
#define SIGS_BYTE 0x08
#define SIGS_RFD 0x80
#define SIGS_IRQ 0x40
#define SIGS_IN0 0x10
#define SIGS_IN1 0x20

#define SIGC_WRITE 0x04
#define SIGC_READ 0x08
#define SIGC_INTEN 0x10

#define DREG 0
#define SREG 1
#define CREG 2

//
#define MTPAV_MODE_INPUT_OPENED     0x01
#define MTPAV_MODE_OUTPUT_OPENED    0x02
#define MTPAV_MODE_INPUT_TRIGGERED  0x04
#define MTPAV_MODE_OUTPUT_TRIGGERED 0x08

#define NUMPORTS (0x12+1)


/*
 */

struct mtpav_port {
    u8 number;
    u8 hwport;
    u8 mode;
    u8 running_status;
    struct snd_rawmidi_substream *input;
    struct snd_rawmidi_substream *output;
};

struct mtpav {
    struct snd_card *card;
    unsigned long port;
    struct resource *res_port;
    int irq;            /* interrupt (for inputs) */
    spinlock_t spinlock;
    int share_irq;          /* number of accesses to input interrupts */
    int istimer;            /* number of accesses to timer interrupts */
    struct timer_list timer;    /* timer interrupts for outputs */
    struct snd_rawmidi *rmidi;
    int num_ports;      /* number of hw ports (1-8) */
    struct mtpav_port ports[NUMPORTS];  /* all ports including computer, adat and bc */

    u32 inmidiport;     /* selected input midi port */
    u32 inmidistate;    /* during midi command 0xf5 */

    u32 outmidihwport;  /* selected output midi hw port */
};


/*
 * possible hardware ports (selected by 0xf5 port message)
 *      0x00        all ports
 *      0x01 .. 0x08    this MTP's ports 1..8
 *      0x09 .. 0x10    networked MTP's ports (9..16)
 *      0x11            networked MTP's computer port
 *      0x63            to ADAT
 *
 * mappig:
 *  subdevice 0 - (X-1)    ports
 *            X - (2*X-1)  networked ports
 *            X            computer
 *            X+1          ADAT
 *            X+2          all ports
 *
 *  where X = chip->num_ports
 */

#define MTPAV_PIDX_COMPUTER 0
#define MTPAV_PIDX_ADAT     1
#define MTPAV_PIDX_BROADCAST    2


static int translate_subdevice_to_hwport(struct mtpav *chip, int subdev)
{
    if (subdev < 0)
        return 0x01; /* invalid - use port 0 as default */
    else if (subdev < chip->num_ports)
        return subdev + 1; /* single mtp port */
    else if (subdev < chip->num_ports * 2)
        return subdev - chip->num_ports + 0x09; /* remote port */
    else if (subdev == chip->num_ports * 2 + MTPAV_PIDX_COMPUTER)
        return 0x11; /* computer port */
    else if (subdev == chip->num_ports + MTPAV_PIDX_ADAT)
        return 0x63;        /* ADAT */
    return 0; /* all ports */
}

static int translate_hwport_to_subdevice(struct mtpav *chip, int hwport)
{
    int p;
    if (hwport <= 0x00) /* all ports */
        return chip->num_ports + MTPAV_PIDX_BROADCAST;
    else if (hwport <= 0x08) { /* single port */
        p = hwport - 1;
        if (p >= chip->num_ports)
            p = 0;
        return p;
    } else if (hwport <= 0x10) { /* remote port */
        p = hwport - 0x09 + chip->num_ports;
        if (p >= chip->num_ports * 2)
            p = chip->num_ports;
        return p;
    } else if (hwport == 0x11)  /* computer port */
        return chip->num_ports + MTPAV_PIDX_COMPUTER;
    else  /* ADAT */
        return chip->num_ports + MTPAV_PIDX_ADAT;
}


/*
 */

static u8 snd_mtpav_getreg(struct mtpav *chip, u16 reg)
{
    u8 rval = 0;

    if (reg == SREG) {
        rval = inb(chip->port + SREG);
        rval = (rval & 0xf8);
    } else if (reg == CREG) {
        rval = inb(chip->port + CREG);
        rval = (rval & 0x1c);
    }

    return rval;
}

/*
 */

static inline void snd_mtpav_mputreg(struct mtpav *chip, u16 reg, u8 val)
{
    if (reg == DREG || reg == CREG)
        outb(val, chip->port + reg);
}

/*
 */

static void snd_mtpav_wait_rfdhi(struct mtpav *chip)
{
    int counts = 10000;
    u8 sbyte;

    sbyte = snd_mtpav_getreg(chip, SREG);
    while (!(sbyte & SIGS_RFD) && counts--) {
        sbyte = snd_mtpav_getreg(chip, SREG);
        udelay(10);
    }
}

static void snd_mtpav_send_byte(struct mtpav *chip, u8 byte)
{
    u8 tcbyt;
    u8 clrwrite;
    u8 setwrite;

    snd_mtpav_wait_rfdhi(chip);


    tcbyt = snd_mtpav_getreg(chip, CREG);
    clrwrite = tcbyt & (SIGC_WRITE ^ 0xff);
    setwrite = tcbyt | SIGC_WRITE;

    snd_mtpav_mputreg(chip, DREG, byte);
    snd_mtpav_mputreg(chip, CREG, clrwrite);    // clear write bit

    snd_mtpav_mputreg(chip, CREG, setwrite);    // set write bit

}


/*
 */

/* call this with spin lock held */
static void snd_mtpav_output_port_write(struct mtpav *mtp_card,
                    struct mtpav_port *portp,
                    struct snd_rawmidi_substream *substream)
{
    u8 outbyte;

    // Get the outbyte first, so we can emulate running status if
    // necessary
    if (snd_rawmidi_transmit(substream, &outbyte, 1) != 1)
        return;

    // send port change command if necessary

    if (portp->hwport != mtp_card->outmidihwport) {
        mtp_card->outmidihwport = portp->hwport;

        snd_mtpav_send_byte(mtp_card, 0xf5);
        snd_mtpav_send_byte(mtp_card, portp->hwport);
        /*
        snd_printk(KERN_DEBUG "new outport: 0x%x\n",
               (unsigned int) portp->hwport);
        */
        if (!(outbyte & 0x80) && portp->running_status)
            snd_mtpav_send_byte(mtp_card, portp->running_status);
    }

    // send data

    do {
        if (outbyte & 0x80)
            portp->running_status = outbyte;
        
        snd_mtpav_send_byte(mtp_card, outbyte);
    } while (snd_rawmidi_transmit(substream, &outbyte, 1) == 1);
}

static void snd_mtpav_output_write(struct snd_rawmidi_substream *substream)
{
    struct mtpav *mtp_card = substream->rmidi->private_data;
    struct mtpav_port *portp = &mtp_card->ports[substream->number];
    unsigned long flags;

    spin_lock_irqsave(&mtp_card->spinlock, flags);
    snd_mtpav_output_port_write(mtp_card, portp, substream);
    spin_unlock_irqrestore(&mtp_card->spinlock, flags);
}


/*
 *      mtpav control
 */

static void snd_mtpav_portscan(struct mtpav *chip)  // put mtp into smart routing mode
{
    u8 p;

    for (p = 0; p < 8; p++) {
        snd_mtpav_send_byte(chip, 0xf5);
        snd_mtpav_send_byte(chip, p);
        snd_mtpav_send_byte(chip, 0xfe);
    }
}

/*
 */

static int snd_mtpav_input_open(struct snd_rawmidi_substream *substream)
{
    struct mtpav *mtp_card = substream->rmidi->private_data;
    struct mtpav_port *portp = &mtp_card->ports[substream->number];
    unsigned long flags;

    spin_lock_irqsave(&mtp_card->spinlock, flags);
    portp->mode |= MTPAV_MODE_INPUT_OPENED;
    portp->input = substream;
    if (mtp_card->share_irq++ == 0)
        snd_mtpav_mputreg(mtp_card, CREG, (SIGC_INTEN | SIGC_WRITE));   // enable pport interrupts
    spin_unlock_irqrestore(&mtp_card->spinlock, flags);
    return 0;
}

/*
 */

static int snd_mtpav_input_close(struct snd_rawmidi_substream *substream)
{
    struct mtpav *mtp_card = substream->rmidi->private_data;
    struct mtpav_port *portp = &mtp_card->ports[substream->number];
    unsigned long flags;

    spin_lock_irqsave(&mtp_card->spinlock, flags);
    portp->mode &= ~MTPAV_MODE_INPUT_OPENED;
    portp->input = NULL;
    if (--mtp_card->share_irq == 0)
        snd_mtpav_mputreg(mtp_card, CREG, 0);   // disable pport interrupts
    spin_unlock_irqrestore(&mtp_card->spinlock, flags);
    return 0;
}

/*
 */

static void snd_mtpav_input_trigger(struct snd_rawmidi_substream *substream, int up)
{
    struct mtpav *mtp_card = substream->rmidi->private_data;
    struct mtpav_port *portp = &mtp_card->ports[substream->number];
    unsigned long flags;

    spin_lock_irqsave(&mtp_card->spinlock, flags);
    if (up)
        portp->mode |= MTPAV_MODE_INPUT_TRIGGERED;
    else
        portp->mode &= ~MTPAV_MODE_INPUT_TRIGGERED;
    spin_unlock_irqrestore(&mtp_card->spinlock, flags);

}


/*
 * timer interrupt for outputs
 */

static void snd_mtpav_output_timer(unsigned long data)
{
    unsigned long flags;
    struct mtpav *chip = (struct mtpav *)data;
    int p;

    spin_lock_irqsave(&chip->spinlock, flags);
    /* reprogram timer */
    chip->timer.expires = 1 + jiffies;
    add_timer(&chip->timer);
    /* process each port */
    for (p = 0; p <= chip->num_ports * 2 + MTPAV_PIDX_BROADCAST; p++) {
        struct mtpav_port *portp = &chip->ports[p];
        if ((portp->mode & MTPAV_MODE_OUTPUT_TRIGGERED) && portp->output)
            snd_mtpav_output_port_write(chip, portp, portp->output);
    }
    spin_unlock_irqrestore(&chip->spinlock, flags);
}

/* spinlock held! */
static void snd_mtpav_add_output_timer(struct mtpav *chip)
{
    chip->timer.expires = 1 + jiffies;
    add_timer(&chip->timer);
}

/* spinlock held! */
static void snd_mtpav_remove_output_timer(struct mtpav *chip)
{
    del_timer(&chip->timer);
}

/*
 */

static int snd_mtpav_output_open(struct snd_rawmidi_substream *substream)
{
    struct mtpav *mtp_card = substream->rmidi->private_data;
    struct mtpav_port *portp = &mtp_card->ports[substream->number];
    unsigned long flags;

    spin_lock_irqsave(&mtp_card->spinlock, flags);
    portp->mode |= MTPAV_MODE_OUTPUT_OPENED;
    portp->output = substream;
    spin_unlock_irqrestore(&mtp_card->spinlock, flags);
    return 0;
};

/*
 */

static int snd_mtpav_output_close(struct snd_rawmidi_substream *substream)
{
    struct mtpav *mtp_card = substream->rmidi->private_data;
    struct mtpav_port *portp = &mtp_card->ports[substream->number];
    unsigned long flags;

    spin_lock_irqsave(&mtp_card->spinlock, flags);
    portp->mode &= ~MTPAV_MODE_OUTPUT_OPENED;
    portp->output = NULL;
    spin_unlock_irqrestore(&mtp_card->spinlock, flags);
    return 0;
};

/*
 */

static void snd_mtpav_output_trigger(struct snd_rawmidi_substream *substream, int up)
{
    struct mtpav *mtp_card = substream->rmidi->private_data;
    struct mtpav_port *portp = &mtp_card->ports[substream->number];
    unsigned long flags;

    spin_lock_irqsave(&mtp_card->spinlock, flags);
    if (up) {
        if (! (portp->mode & MTPAV_MODE_OUTPUT_TRIGGERED)) {
            if (mtp_card->istimer++ == 0)
                snd_mtpav_add_output_timer(mtp_card);
            portp->mode |= MTPAV_MODE_OUTPUT_TRIGGERED;
        }
    } else {
        portp->mode &= ~MTPAV_MODE_OUTPUT_TRIGGERED;
        if (--mtp_card->istimer == 0)
            snd_mtpav_remove_output_timer(mtp_card);
    }
    spin_unlock_irqrestore(&mtp_card->spinlock, flags);

    if (up)
        snd_mtpav_output_write(substream);
}

/*
 * midi interrupt for inputs
 */

static void snd_mtpav_inmidi_process(struct mtpav *mcrd, u8 inbyte)
{
    struct mtpav_port *portp;

    if ((int)mcrd->inmidiport > mcrd->num_ports * 2 + MTPAV_PIDX_BROADCAST)
        return;

    portp = &mcrd->ports[mcrd->inmidiport];
    if (portp->mode & MTPAV_MODE_INPUT_TRIGGERED)
        snd_rawmidi_receive(portp->input, &inbyte, 1);
}

static void snd_mtpav_inmidi_h(struct mtpav *mcrd, u8 inbyte)
{
    if (inbyte >= 0xf8) {
        /* real-time midi code */
        snd_mtpav_inmidi_process(mcrd, inbyte);
        return;
    }

    if (mcrd->inmidistate == 0) {   // awaiting command
        if (inbyte == 0xf5) // MTP port #
            mcrd->inmidistate = 1;
        else
            snd_mtpav_inmidi_process(mcrd, inbyte);
    } else if (mcrd->inmidistate) {
        mcrd->inmidiport = translate_hwport_to_subdevice(mcrd, inbyte);
        mcrd->inmidistate = 0;
    }
}

static void snd_mtpav_read_bytes(struct mtpav *mcrd)
{
    u8 clrread, setread;
    u8 mtp_read_byte;
    u8 sr, cbyt;
    int i;

    u8 sbyt = snd_mtpav_getreg(mcrd, SREG);

    /* printk(KERN_DEBUG "snd_mtpav_read_bytes() sbyt: 0x%x\n", sbyt); */

    if (!(sbyt & SIGS_BYTE))
        return;

    cbyt = snd_mtpav_getreg(mcrd, CREG);
    clrread = cbyt & (SIGC_READ ^ 0xff);
    setread = cbyt | SIGC_READ;

    do {

        mtp_read_byte = 0;
        for (i = 0; i < 4; i++) {
            snd_mtpav_mputreg(mcrd, CREG, setread);
            sr = snd_mtpav_getreg(mcrd, SREG);
            snd_mtpav_mputreg(mcrd, CREG, clrread);

            sr &= SIGS_IN0 | SIGS_IN1;
            sr >>= 4;
            mtp_read_byte |= sr << (i * 2);
        }

        snd_mtpav_inmidi_h(mcrd, mtp_read_byte);

        sbyt = snd_mtpav_getreg(mcrd, SREG);

    } while (sbyt & SIGS_BYTE);
}

static irqreturn_t snd_mtpav_irqh(int irq, void *dev_id)
{
    struct mtpav *mcard = dev_id;

    spin_lock(&mcard->spinlock);
    snd_mtpav_read_bytes(mcard);
    spin_unlock(&mcard->spinlock);
    return IRQ_HANDLED;
}

/*
 * get ISA resources
 */
static int __devinit snd_mtpav_get_ISA(struct mtpav * mcard)
{
    if ((mcard->res_port = request_region(port, 3, "MotuMTPAV MIDI")) == NULL) {
        snd_printk(KERN_ERR "MTVAP port 0x%lx is busy\n", port);
        return -EBUSY;
    }
    mcard->port = port;
    if (request_irq(irq, snd_mtpav_irqh, 0, "MOTU MTPAV", mcard)) {
        snd_printk(KERN_ERR "MTVAP IRQ %d busy\n", irq);
        return -EBUSY;
    }
    mcard->irq = irq;
    return 0;
}


/*
 */

static struct snd_rawmidi_ops snd_mtpav_output = {
    .open =     snd_mtpav_output_open,
    .close =    snd_mtpav_output_close,
    .trigger =  snd_mtpav_output_trigger,
};

static struct snd_rawmidi_ops snd_mtpav_input = {
    .open =     snd_mtpav_input_open,
    .close =    snd_mtpav_input_close,
    .trigger =  snd_mtpav_input_trigger,
};


/*
 * get RAWMIDI resources
 */

static void __devinit snd_mtpav_set_name(struct mtpav *chip,
                      struct snd_rawmidi_substream *substream)
{
    if (substream->number >= 0 && substream->number < chip->num_ports)
        sprintf(substream->name, "MTP direct %d", (substream->number % chip->num_ports) + 1);
    else if (substream->number >= 8 && substream->number < chip->num_ports * 2)
        sprintf(substream->name, "MTP remote %d", (substream->number % chip->num_ports) + 1);
    else if (substream->number == chip->num_ports * 2)
        strcpy(substream->name, "MTP computer");
    else if (substream->number == chip->num_ports * 2 + 1)
        strcpy(substream->name, "MTP ADAT");
    else
        strcpy(substream->name, "MTP broadcast");
}

static int __devinit snd_mtpav_get_RAWMIDI(struct mtpav *mcard)
{
    int rval;
    struct snd_rawmidi *rawmidi;
    struct snd_rawmidi_substream *substream;
    struct list_head *list;

    if (hwports < 1)
        hwports = 1;
    else if (hwports > 8)
        hwports = 8;
    mcard->num_ports = hwports;

    if ((rval = snd_rawmidi_new(mcard->card, "MotuMIDI", 0,
                    mcard->num_ports * 2 + MTPAV_PIDX_BROADCAST + 1,
                    mcard->num_ports * 2 + MTPAV_PIDX_BROADCAST + 1,
                    &mcard->rmidi)) < 0)
        return rval;
    rawmidi = mcard->rmidi;
    rawmidi->private_data = mcard;

    list_for_each(list, &rawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams) {
        substream = list_entry(list, struct snd_rawmidi_substream, list);
        snd_mtpav_set_name(mcard, substream);
        substream->ops = &snd_mtpav_input;
    }
    list_for_each(list, &rawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams) {
        substream = list_entry(list, struct snd_rawmidi_substream, list);
        snd_mtpav_set_name(mcard, substream);
        substream->ops = &snd_mtpav_output;
        mcard->ports[substream->number].hwport = translate_subdevice_to_hwport(mcard, substream->number);
    }
    rawmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT | SNDRV_RAWMIDI_INFO_INPUT |
                   SNDRV_RAWMIDI_INFO_DUPLEX;
    sprintf(rawmidi->name, "MTP AV MIDI");
    return 0;
}

/*
 */

static void snd_mtpav_free(struct snd_card *card)
{
    struct mtpav *crd = card->private_data;
    unsigned long flags;

    spin_lock_irqsave(&crd->spinlock, flags);
    if (crd->istimer > 0)
        snd_mtpav_remove_output_timer(crd);
    spin_unlock_irqrestore(&crd->spinlock, flags);
    if (crd->irq >= 0)
        free_irq(crd->irq, (void *)crd);
    release_and_free_resource(crd->res_port);
}

/*
 */
static int __devinit snd_mtpav_probe(struct platform_device *dev)
{
    struct snd_card *card;
    int err;
    struct mtpav *mtp_card;

    err = snd_card_create(index, id, THIS_MODULE, sizeof(*mtp_card), &card);
    if (err < 0)
        return err;

    mtp_card = card->private_data;
    spin_lock_init(&mtp_card->spinlock);
    init_timer(&mtp_card->timer);
    mtp_card->card = card;
    mtp_card->irq = -1;
    mtp_card->share_irq = 0;
    mtp_card->inmidistate = 0;
    mtp_card->outmidihwport = 0xffffffff;
    init_timer(&mtp_card->timer);
    mtp_card->timer.function = snd_mtpav_output_timer;
    mtp_card->timer.data = (unsigned long) mtp_card;

    card->private_free = snd_mtpav_free;

    err = snd_mtpav_get_RAWMIDI(mtp_card);
    if (err < 0)
        goto __error;

    mtp_card->inmidiport = mtp_card->num_ports + MTPAV_PIDX_BROADCAST;

    err = snd_mtpav_get_ISA(mtp_card);
    if (err < 0)
        goto __error;

    strcpy(card->driver, "MTPAV");
    strcpy(card->shortname, "MTPAV on parallel port");
    snprintf(card->longname, sizeof(card->longname),
         "MTPAV on parallel port at 0x%lx", port);

    snd_mtpav_portscan(mtp_card);

    snd_card_set_dev(card, &dev->dev);
    err = snd_card_register(mtp_card->card);
    if (err < 0)
        goto __error;

    platform_set_drvdata(dev, card);
    printk(KERN_INFO "Motu MidiTimePiece on parallel port irq: %d ioport: 0x%lx\n", irq, port);
    return 0;

 __error:
    snd_card_free(card);
    return err;
}

static int __devexit snd_mtpav_remove(struct platform_device *devptr)
{
    snd_card_free(platform_get_drvdata(devptr));
    platform_set_drvdata(devptr, NULL);
    return 0;
}

#define SND_MTPAV_DRIVER    "snd_mtpav"

static struct platform_driver snd_mtpav_driver = {
    .probe      = snd_mtpav_probe,
    .remove     = __devexit_p(snd_mtpav_remove),
    .driver     = {
        .name   = SND_MTPAV_DRIVER,
        .owner  = THIS_MODULE,
    },
};

static int __init alsa_card_mtpav_init(void)
{
    int err;

    if ((err = platform_driver_register(&snd_mtpav_driver)) < 0)
        return err;

    device = platform_device_register_simple(SND_MTPAV_DRIVER, -1, NULL, 0);
    if (!IS_ERR(device)) {
        if (platform_get_drvdata(device))
            return 0;
        platform_device_unregister(device);
        err = -ENODEV;
    } else
        err = PTR_ERR(device);
    platform_driver_unregister(&snd_mtpav_driver);
    return err;
}

static void __exit alsa_card_mtpav_exit(void)
{
    platform_device_unregister(device);
    platform_driver_unregister(&snd_mtpav_driver);
}

module_init(alsa_card_mtpav_init)
module_exit(alsa_card_mtpav_exit)