Linux 2.6.38-rc4

[linux-2.6/next.git] / sound / drivers / portman2x4.c

/*
 *   Driver for Midiman Portman2x4 parallel port midi interface
 *
 *   Copyright (c) by Levent Guendogdu <levon@feature-it.com>
 *
 *   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.
 *
 * ChangeLog
 * Jan 24 2007 Matthias Koenig <mkoenig@suse.de>
 *      - cleanup and rewrite
 * Sep 30 2004 Tobias Gehrig <tobias@gehrig.tk>
 *      - source code cleanup
 * Sep 03 2004 Tobias Gehrig <tobias@gehrig.tk>
 *      - fixed compilation problem with alsa 1.0.6a (removed MODULE_CLASSES,
 *        MODULE_PARM_SYNTAX and changed MODULE_DEVICES to
 *        MODULE_SUPPORTED_DEVICE)
 * Mar 24 2004 Tobias Gehrig <tobias@gehrig.tk>
 *      - added 2.6 kernel support
 * Mar 18 2004 Tobias Gehrig <tobias@gehrig.tk>
 *      - added parport_unregister_driver to the startup routine if the driver fails to detect a portman
 *      - added support for all 4 output ports in portman_putmidi
 * Mar 17 2004 Tobias Gehrig <tobias@gehrig.tk>
 *      - added checks for opened input device in interrupt handler
 * Feb 20 2004 Tobias Gehrig <tobias@gehrig.tk>
 *      - ported from alsa 0.5 to 1.0
 */

#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/parport.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/rawmidi.h>
#include <sound/control.h>

#define CARD_NAME "Portman 2x4"
#define DRIVER_NAME "portman"
#define PLATFORM_DRIVER "snd_portman2x4"

static int index[SNDRV_CARDS]  = SNDRV_DEFAULT_IDX;
static char *id[SNDRV_CARDS]   = SNDRV_DEFAULT_STR;
static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;

static struct platform_device *platform_devices[SNDRV_CARDS]; 
static int device_count;

module_param_array(index, int, NULL, S_IRUGO);
MODULE_PARM_DESC(index, "Index value for " CARD_NAME " soundcard.");
module_param_array(id, charp, NULL, S_IRUGO);
MODULE_PARM_DESC(id, "ID string for " CARD_NAME " soundcard.");
module_param_array(enable, bool, NULL, S_IRUGO);
MODULE_PARM_DESC(enable, "Enable " CARD_NAME " soundcard.");

MODULE_AUTHOR("Levent Guendogdu, Tobias Gehrig, Matthias Koenig");
MODULE_DESCRIPTION("Midiman Portman2x4");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{Midiman,Portman2x4}}");

/*********************************************************************
 * Chip specific
 *********************************************************************/
#define PORTMAN_NUM_INPUT_PORTS 2
#define PORTMAN_NUM_OUTPUT_PORTS 4

struct portman {
        spinlock_t reg_lock;
        struct snd_card *card;
        struct snd_rawmidi *rmidi;
        struct pardevice *pardev;
        int pardev_claimed;

        int open_count;
        int mode[PORTMAN_NUM_INPUT_PORTS];
        struct snd_rawmidi_substream *midi_input[PORTMAN_NUM_INPUT_PORTS];
};

static int portman_free(struct portman *pm)
{
        kfree(pm);
        return 0;
}

static int __devinit portman_create(struct snd_card *card, 
                                    struct pardevice *pardev, 
                                    struct portman **rchip)
{
        struct portman *pm;

        *rchip = NULL;

        pm = kzalloc(sizeof(struct portman), GFP_KERNEL);
        if (pm == NULL) 
                return -ENOMEM;

        /* Init chip specific data */
        spin_lock_init(&pm->reg_lock);
        pm->card = card;
        pm->pardev = pardev;

        *rchip = pm;

        return 0;
}

/*********************************************************************
 * HW related constants
 *********************************************************************/

/* Standard PC parallel port status register equates. */
#define PP_STAT_BSY     0x80    /* Busy status.  Inverted. */
#define PP_STAT_ACK     0x40    /* Acknowledge.  Non-Inverted. */
#define PP_STAT_POUT    0x20    /* Paper Out.    Non-Inverted. */
#define PP_STAT_SEL     0x10    /* Select.       Non-Inverted. */
#define PP_STAT_ERR     0x08    /* Error.        Non-Inverted. */

/* Standard PC parallel port command register equates. */
#define PP_CMD_IEN      0x10    /* IRQ Enable.   Non-Inverted. */
#define PP_CMD_SELI     0x08    /* Select Input. Inverted. */
#define PP_CMD_INIT     0x04    /* Init Printer. Non-Inverted. */
#define PP_CMD_FEED     0x02    /* Auto Feed.    Inverted. */
#define PP_CMD_STB      0x01    /* Strobe.       Inverted. */

/* Parallel Port Command Register as implemented by PCP2x4. */
#define INT_EN          PP_CMD_IEN      /* Interrupt enable. */
#define STROBE          PP_CMD_STB      /* Command strobe. */

/* The parallel port command register field (b1..b3) selects the 
 * various "registers" within the PC/P 2x4.  These are the internal
 * address of these "registers" that must be written to the parallel
 * port command register.
 */
#define RXDATA0         (0 << 1)        /* PCP RxData channel 0. */
#define RXDATA1         (1 << 1)        /* PCP RxData channel 1. */
#define GEN_CTL         (2 << 1)        /* PCP General Control Register. */
#define SYNC_CTL        (3 << 1)        /* PCP Sync Control Register. */
#define TXDATA0         (4 << 1)        /* PCP TxData channel 0. */
#define TXDATA1         (5 << 1)        /* PCP TxData channel 1. */
#define TXDATA2         (6 << 1)        /* PCP TxData channel 2. */
#define TXDATA3         (7 << 1)        /* PCP TxData channel 3. */

/* Parallel Port Status Register as implemented by PCP2x4. */
#define ESTB            PP_STAT_POUT    /* Echoed strobe. */
#define INT_REQ         PP_STAT_ACK     /* Input data int request. */
#define BUSY            PP_STAT_ERR     /* Interface Busy. */

/* Parallel Port Status Register BUSY and SELECT lines are multiplexed
 * between several functions.  Depending on which 2x4 "register" is
 * currently selected (b1..b3), the BUSY and SELECT lines are
 * assigned as follows:
 *
 *   SELECT LINE:                                                    A3 A2 A1
 *                                                                   --------
 */
#define RXAVAIL         PP_STAT_SEL     /* Rx Available, channel 0.   0 0 0 */
//  RXAVAIL1    PP_STAT_SEL             /* Rx Available, channel 1.   0 0 1 */
#define SYNC_STAT       PP_STAT_SEL     /* Reserved - Sync Status.    0 1 0 */
//                                      /* Reserved.                  0 1 1 */
#define TXEMPTY         PP_STAT_SEL     /* Tx Empty, channel 0.       1 0 0 */
//      TXEMPTY1        PP_STAT_SEL     /* Tx Empty, channel 1.       1 0 1 */
//  TXEMPTY2    PP_STAT_SEL             /* Tx Empty, channel 2.       1 1 0 */
//  TXEMPTY3    PP_STAT_SEL             /* Tx Empty, channel 3.       1 1 1 */

/*   BUSY LINE:                                                      A3 A2 A1
 *                                                                   --------
 */
#define RXDATA          PP_STAT_BSY     /* Rx Input Data, channel 0.  0 0 0 */
//      RXDATA1         PP_STAT_BSY     /* Rx Input Data, channel 1.  0 0 1 */
#define SYNC_DATA       PP_STAT_BSY     /* Reserved - Sync Data.      0 1 0 */
                                        /* Reserved.                  0 1 1 */
#define DATA_ECHO       PP_STAT_BSY     /* Parallel Port Data Echo.   1 0 0 */
#define A0_ECHO         PP_STAT_BSY     /* Address 0 Echo.            1 0 1 */
#define A1_ECHO         PP_STAT_BSY     /* Address 1 Echo.            1 1 0 */
#define A2_ECHO         PP_STAT_BSY     /* Address 2 Echo.            1 1 1 */

#define PORTMAN2X4_MODE_INPUT_TRIGGERED  0x01

/*********************************************************************
 * Hardware specific functions
 *********************************************************************/
static inline void portman_write_command(struct portman *pm, u8 value)
{
        parport_write_control(pm->pardev->port, value);
}

static inline u8 portman_read_command(struct portman *pm)
{
        return parport_read_control(pm->pardev->port);
}

static inline u8 portman_read_status(struct portman *pm)
{
        return parport_read_status(pm->pardev->port);
}

static inline u8 portman_read_data(struct portman *pm)
{
        return parport_read_data(pm->pardev->port);
}

static inline void portman_write_data(struct portman *pm, u8 value)
{
        parport_write_data(pm->pardev->port, value);
}

static void portman_write_midi(struct portman *pm, 
                               int port, u8 mididata)
{
        int command = ((port + 4) << 1);

        /* Get entering data byte and port number in BL and BH respectively.
         * Set up Tx Channel address field for use with PP Cmd Register.
         * Store address field in BH register.
         * Inputs:      AH = Output port number (0..3).
         *              AL = Data byte.
         *    command = TXDATA0 | INT_EN;
         * Align port num with address field (b1...b3),
         * set address for TXDatax, Strobe=0
         */
        command |= INT_EN;

        /* Disable interrupts so that the process is not interrupted, then 
         * write the address associated with the current Tx channel to the 
         * PP Command Reg.  Do not set the Strobe signal yet.
         */

        do {
                portman_write_command(pm, command);

                /* While the address lines settle, write parallel output data to 
                 * PP Data Reg.  This has no effect until Strobe signal is asserted.
                 */

                portman_write_data(pm, mididata);
                
                /* If PCP channel's TxEmpty is set (TxEmpty is read through the PP
                 * Status Register), then go write data.  Else go back and wait.
                 */
        } while ((portman_read_status(pm) & TXEMPTY) != TXEMPTY);

        /* TxEmpty is set.  Maintain PC/P destination address and assert
         * Strobe through the PP Command Reg.  This will Strobe data into
         * the PC/P transmitter and set the PC/P BUSY signal.
         */

        portman_write_command(pm, command | STROBE);

        /* Wait for strobe line to settle and echo back through hardware.
         * Once it has echoed back, assume that the address and data lines
         * have settled!
         */

        while ((portman_read_status(pm) & ESTB) == 0)
                cpu_relax();

        /* Release strobe and immediately re-allow interrupts. */
        portman_write_command(pm, command);

        while ((portman_read_status(pm) & ESTB) == ESTB)
                cpu_relax();

        /* PC/P BUSY is now set.  We must wait until BUSY resets itself.
         * We'll reenable ints while we're waiting.
         */

        while ((portman_read_status(pm) & BUSY) == BUSY)
                cpu_relax();

        /* Data sent. */
}


/*
 *  Read MIDI byte from port
 *  Attempt to read input byte from specified hardware input port (0..).
 *  Return -1 if no data
 */
static int portman_read_midi(struct portman *pm, int port)
{
        unsigned char midi_data = 0;
        unsigned char cmdout;   /* Saved address+IE bit. */

        /* Make sure clocking edge is down before starting... */
        portman_write_data(pm, 0);      /* Make sure edge is down. */

        /* Set destination address to PCP. */
        cmdout = (port << 1) | INT_EN;  /* Address + IE + No Strobe. */
        portman_write_command(pm, cmdout);

        while ((portman_read_status(pm) & ESTB) == ESTB)
                cpu_relax();    /* Wait for strobe echo. */

        /* After the address lines settle, check multiplexed RxAvail signal.
         * If data is available, read it.
         */
        if ((portman_read_status(pm) & RXAVAIL) == 0)
                return -1;      /* No data. */

        /* Set the Strobe signal to enable the Rx clocking circuitry. */
        portman_write_command(pm, cmdout | STROBE);     /* Write address+IE+Strobe. */

        while ((portman_read_status(pm) & ESTB) == 0)
                cpu_relax(); /* Wait for strobe echo. */

        /* The first data bit (msb) is already sitting on the input line. */
        midi_data = (portman_read_status(pm) & 128);
        portman_write_data(pm, 1);      /* Cause rising edge, which shifts data. */

        /* Data bit 6. */
        portman_write_data(pm, 0);      /* Cause falling edge while data settles. */
        midi_data |= (portman_read_status(pm) >> 1) & 64;
        portman_write_data(pm, 1);      /* Cause rising edge, which shifts data. */

        /* Data bit 5. */
        portman_write_data(pm, 0);      /* Cause falling edge while data settles. */
        midi_data |= (portman_read_status(pm) >> 2) & 32;
        portman_write_data(pm, 1);      /* Cause rising edge, which shifts data. */

        /* Data bit 4. */
        portman_write_data(pm, 0);      /* Cause falling edge while data settles. */
        midi_data |= (portman_read_status(pm) >> 3) & 16;
        portman_write_data(pm, 1);      /* Cause rising edge, which shifts data. */

        /* Data bit 3. */
        portman_write_data(pm, 0);      /* Cause falling edge while data settles. */
        midi_data |= (portman_read_status(pm) >> 4) & 8;
        portman_write_data(pm, 1);      /* Cause rising edge, which shifts data. */

        /* Data bit 2. */
        portman_write_data(pm, 0);      /* Cause falling edge while data settles. */
        midi_data |= (portman_read_status(pm) >> 5) & 4;
        portman_write_data(pm, 1);      /* Cause rising edge, which shifts data. */

        /* Data bit 1. */
        portman_write_data(pm, 0);      /* Cause falling edge while data settles. */
        midi_data |= (portman_read_status(pm) >> 6) & 2;
        portman_write_data(pm, 1);      /* Cause rising edge, which shifts data. */

        /* Data bit 0. */
        portman_write_data(pm, 0);      /* Cause falling edge while data settles. */
        midi_data |= (portman_read_status(pm) >> 7) & 1;
        portman_write_data(pm, 1);      /* Cause rising edge, which shifts data. */
        portman_write_data(pm, 0);      /* Return data clock low. */


        /* De-assert Strobe and return data. */
        portman_write_command(pm, cmdout);      /* Output saved address+IE. */

        /* Wait for strobe echo. */
        while ((portman_read_status(pm) & ESTB) == ESTB)
                cpu_relax();

        return (midi_data & 255);       /* Shift back and return value. */
}

/*
 *  Checks if any input data on the given channel is available
 *  Checks RxAvail 
 */
static int portman_data_avail(struct portman *pm, int channel)
{
        int command = INT_EN;
        switch (channel) {
        case 0:
                command |= RXDATA0;
                break;
        case 1:
                command |= RXDATA1;
                break;
        }
        /* Write hardware (assumme STROBE=0) */
        portman_write_command(pm, command);
        /* Check multiplexed RxAvail signal */
        if ((portman_read_status(pm) & RXAVAIL) == RXAVAIL)
                return 1;       /* Data available */

        /* No Data available */
        return 0;
}


/*
 *  Flushes any input
 */
static void portman_flush_input(struct portman *pm, unsigned char port)
{
        /* Local variable for counting things */
        unsigned int i = 0;
        unsigned char command = 0;

        switch (port) {
        case 0:
                command = RXDATA0;
                break;
        case 1:
                command = RXDATA1;
                break;
        default:
                snd_printk(KERN_WARNING
                           "portman_flush_input() Won't flush port %i\n",
                           port);
                return;
        }

        /* Set address for specified channel in port and allow to settle. */
        portman_write_command(pm, command);

        /* Assert the Strobe and wait for echo back. */
        portman_write_command(pm, command | STROBE);

        /* Wait for ESTB */
        while ((portman_read_status(pm) & ESTB) == 0)
                cpu_relax();

        /* Output clock cycles to the Rx circuitry. */
        portman_write_data(pm, 0);

        /* Flush 250 bits... */
        for (i = 0; i < 250; i++) {
                portman_write_data(pm, 1);
                portman_write_data(pm, 0);
        }

        /* Deassert the Strobe signal of the port and wait for it to settle. */
        portman_write_command(pm, command | INT_EN);

        /* Wait for settling */
        while ((portman_read_status(pm) & ESTB) == ESTB)
                cpu_relax();
}

static int portman_probe(struct parport *p)
{
        /* Initialize the parallel port data register.  Will set Rx clocks
         * low in case we happen to be addressing the Rx ports at this time.
         */
        /* 1 */
        parport_write_data(p, 0);

        /* Initialize the parallel port command register, thus initializing
         * hardware handshake lines to midi box:
         *
         *                                  Strobe = 0
         *                                  Interrupt Enable = 0            
         */
        /* 2 */
        parport_write_control(p, 0);

        /* Check if Portman PC/P 2x4 is out there. */
        /* 3 */
        parport_write_control(p, RXDATA0);      /* Write Strobe=0 to command reg. */

        /* Check for ESTB to be clear */
        /* 4 */
        if ((parport_read_status(p) & ESTB) == ESTB)
                return 1;       /* CODE 1 - Strobe Failure. */

        /* Set for RXDATA0 where no damage will be done. */
        /* 5 */
        parport_write_control(p, RXDATA0 + STROBE);     /* Write Strobe=1 to command reg. */

        /* 6 */
        if ((parport_read_status(p) & ESTB) != ESTB)
                return 1;       /* CODE 1 - Strobe Failure. */

        /* 7 */
        parport_write_control(p, 0);    /* Reset Strobe=0. */

        /* Check if Tx circuitry is functioning properly.  If initialized 
         * unit TxEmpty is false, send out char and see if if goes true.
         */
        /* 8 */
        parport_write_control(p, TXDATA0);      /* Tx channel 0, strobe off. */

        /* If PCP channel's TxEmpty is set (TxEmpty is read through the PP
         * Status Register), then go write data.  Else go back and wait.
         */
        /* 9 */
        if ((parport_read_status(p) & TXEMPTY) == 0)
                return 2;

        /* Return OK status. */
        return 0;
}

static int portman_device_init(struct portman *pm)
{
        portman_flush_input(pm, 0);
        portman_flush_input(pm, 1);

        return 0;
}

/*********************************************************************
 * Rawmidi
 *********************************************************************/
static int snd_portman_midi_open(struct snd_rawmidi_substream *substream)
{
        return 0;
}

static int snd_portman_midi_close(struct snd_rawmidi_substream *substream)
{
        return 0;
}

static void snd_portman_midi_input_trigger(struct snd_rawmidi_substream *substream,
                                           int up)
{
        struct portman *pm = substream->rmidi->private_data;
        unsigned long flags;

        spin_lock_irqsave(&pm->reg_lock, flags);
        if (up)
                pm->mode[substream->number] |= PORTMAN2X4_MODE_INPUT_TRIGGERED;
        else
                pm->mode[substream->number] &= ~PORTMAN2X4_MODE_INPUT_TRIGGERED;
        spin_unlock_irqrestore(&pm->reg_lock, flags);
}

static void snd_portman_midi_output_trigger(struct snd_rawmidi_substream *substream,
                                            int up)
{
        struct portman *pm = substream->rmidi->private_data;
        unsigned long flags;
        unsigned char byte;

        spin_lock_irqsave(&pm->reg_lock, flags);
        if (up) {
                while ((snd_rawmidi_transmit(substream, &byte, 1) == 1))
                        portman_write_midi(pm, substream->number, byte);
        }
        spin_unlock_irqrestore(&pm->reg_lock, flags);
}

static struct snd_rawmidi_ops snd_portman_midi_output = {
        .open =         snd_portman_midi_open,
        .close =        snd_portman_midi_close,
        .trigger =      snd_portman_midi_output_trigger,
};

static struct snd_rawmidi_ops snd_portman_midi_input = {
        .open =         snd_portman_midi_open,
        .close =        snd_portman_midi_close,
        .trigger =      snd_portman_midi_input_trigger,
};

/* Create and initialize the rawmidi component */
static int __devinit snd_portman_rawmidi_create(struct snd_card *card)
{
        struct portman *pm = card->private_data;
        struct snd_rawmidi *rmidi;
        struct snd_rawmidi_substream *substream;
        int err;
        
        err = snd_rawmidi_new(card, CARD_NAME, 0, 
                              PORTMAN_NUM_OUTPUT_PORTS, 
                              PORTMAN_NUM_INPUT_PORTS, 
                              &rmidi);
        if (err < 0) 
                return err;

        rmidi->private_data = pm;
        strcpy(rmidi->name, CARD_NAME);
        rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
                            SNDRV_RAWMIDI_INFO_INPUT |
                            SNDRV_RAWMIDI_INFO_DUPLEX;

        pm->rmidi = rmidi;

        /* register rawmidi ops */
        snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, 
                            &snd_portman_midi_output);
        snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, 
                            &snd_portman_midi_input);

        /* name substreams */
        /* output */
        list_for_each_entry(substream,
                            &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams,
                            list) {
                sprintf(substream->name,
                        "Portman2x4 %d", substream->number+1);
        }
        /* input */
        list_for_each_entry(substream,
                            &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams,
                            list) {
                pm->midi_input[substream->number] = substream;
                sprintf(substream->name,
                        "Portman2x4 %d", substream->number+1);
        }

        return err;
}

/*********************************************************************
 * parport stuff
 *********************************************************************/
static void snd_portman_interrupt(void *userdata)
{
        unsigned char midivalue = 0;
        struct portman *pm = ((struct snd_card*)userdata)->private_data;

        spin_lock(&pm->reg_lock);

        /* While any input data is waiting */
        while ((portman_read_status(pm) & INT_REQ) == INT_REQ) {
                /* If data available on channel 0, 
                   read it and stuff it into the queue. */
                if (portman_data_avail(pm, 0)) {
                        /* Read Midi */
                        midivalue = portman_read_midi(pm, 0);
                        /* put midi into queue... */
                        if (pm->mode[0] & PORTMAN2X4_MODE_INPUT_TRIGGERED)
                                snd_rawmidi_receive(pm->midi_input[0],
                                                    &midivalue, 1);

                }
                /* If data available on channel 1, 
                   read it and stuff it into the queue. */
                if (portman_data_avail(pm, 1)) {
                        /* Read Midi */
                        midivalue = portman_read_midi(pm, 1);
                        /* put midi into queue... */
                        if (pm->mode[1] & PORTMAN2X4_MODE_INPUT_TRIGGERED)
                                snd_rawmidi_receive(pm->midi_input[1],
                                                    &midivalue, 1);
                }

        }

        spin_unlock(&pm->reg_lock);
}

static int __devinit snd_portman_probe_port(struct parport *p)
{
        struct pardevice *pardev;
        int res;

        pardev = parport_register_device(p, DRIVER_NAME,
                                         NULL, NULL, NULL,
                                         0, NULL);
        if (!pardev)
                return -EIO;
        
        if (parport_claim(pardev)) {
                parport_unregister_device(pardev);
                return -EIO;
        }

        res = portman_probe(p);

        parport_release(pardev);
        parport_unregister_device(pardev);

        return res ? -EIO : 0;
}

static void __devinit snd_portman_attach(struct parport *p)
{
        struct platform_device *device;

        device = platform_device_alloc(PLATFORM_DRIVER, device_count);
        if (!device)
                return;

        /* Temporary assignment to forward the parport */
        platform_set_drvdata(device, p);

        if (platform_device_add(device) < 0) {
                platform_device_put(device);
                return;
        }

        /* Since we dont get the return value of probe
         * We need to check if device probing succeeded or not */
        if (!platform_get_drvdata(device)) {
                platform_device_unregister(device);
                return;
        }

        /* register device in global table */
        platform_devices[device_count] = device;
        device_count++;
}

static void snd_portman_detach(struct parport *p)
{
        /* nothing to do here */
}

static struct parport_driver portman_parport_driver = {
        .name   = "portman2x4",
        .attach = snd_portman_attach,
        .detach = snd_portman_detach
};

/*********************************************************************
 * platform stuff
 *********************************************************************/
static void snd_portman_card_private_free(struct snd_card *card)
{
        struct portman *pm = card->private_data;
        struct pardevice *pardev = pm->pardev;

        if (pardev) {
                if (pm->pardev_claimed)
                        parport_release(pardev);
                parport_unregister_device(pardev);
        }

        portman_free(pm);
}

static int __devinit snd_portman_probe(struct platform_device *pdev)
{
        struct pardevice *pardev;
        struct parport *p;
        int dev = pdev->id;
        struct snd_card *card = NULL;
        struct portman *pm = NULL;
        int err;

        p = platform_get_drvdata(pdev);
        platform_set_drvdata(pdev, NULL);

        if (dev >= SNDRV_CARDS)
                return -ENODEV;
        if (!enable[dev]) 
                return -ENOENT;

        if ((err = snd_portman_probe_port(p)) < 0)
                return err;

        err = snd_card_create(index[dev], id[dev], THIS_MODULE, 0, &card);
        if (err < 0) {
                snd_printd("Cannot create card\n");
                return err;
        }
        strcpy(card->driver, DRIVER_NAME);
        strcpy(card->shortname, CARD_NAME);
        sprintf(card->longname,  "%s at 0x%lx, irq %i", 
                card->shortname, p->base, p->irq);

        pardev = parport_register_device(p,                     /* port */
                                         DRIVER_NAME,           /* name */
                                         NULL,                  /* preempt */
                                         NULL,                  /* wakeup */
                                         snd_portman_interrupt, /* ISR */
                                         PARPORT_DEV_EXCL,      /* flags */
                                         (void *)card);         /* private */
        if (pardev == NULL) {
                snd_printd("Cannot register pardevice\n");
                err = -EIO;
                goto __err;
        }

        if ((err = portman_create(card, pardev, &pm)) < 0) {
                snd_printd("Cannot create main component\n");
                parport_unregister_device(pardev);
                goto __err;
        }
        card->private_data = pm;
        card->private_free = snd_portman_card_private_free;
        
        if ((err = snd_portman_rawmidi_create(card)) < 0) {
                snd_printd("Creating Rawmidi component failed\n");
                goto __err;
        }

        /* claim parport */
        if (parport_claim(pardev)) {
                snd_printd("Cannot claim parport 0x%lx\n", pardev->port->base);
                err = -EIO;
                goto __err;
        }
        pm->pardev_claimed = 1;

        /* init device */
        if ((err = portman_device_init(pm)) < 0)
                goto __err;

        platform_set_drvdata(pdev, card);

        snd_card_set_dev(card, &pdev->dev);

        /* At this point card will be usable */
        if ((err = snd_card_register(card)) < 0) {
                snd_printd("Cannot register card\n");
                goto __err;
        }

        snd_printk(KERN_INFO "Portman 2x4 on 0x%lx\n", p->base);
        return 0;

__err:
        snd_card_free(card);
        return err;
}

static int __devexit snd_portman_remove(struct platform_device *pdev)
{
        struct snd_card *card = platform_get_drvdata(pdev);

        if (card)
                snd_card_free(card);

        return 0;
}


static struct platform_driver snd_portman_driver = {
        .probe  = snd_portman_probe,
        .remove = __devexit_p(snd_portman_remove),
        .driver = {
                .name = PLATFORM_DRIVER
        }
};

/*********************************************************************
 * module init stuff
 *********************************************************************/
static void snd_portman_unregister_all(void)
{
        int i;

        for (i = 0; i < SNDRV_CARDS; ++i) {
                if (platform_devices[i]) {
                        platform_device_unregister(platform_devices[i]);
                        platform_devices[i] = NULL;
                }
        }               
        platform_driver_unregister(&snd_portman_driver);
        parport_unregister_driver(&portman_parport_driver);
}

static int __init snd_portman_module_init(void)
{
        int err;

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

        if (parport_register_driver(&portman_parport_driver) != 0) {
                platform_driver_unregister(&snd_portman_driver);
                return -EIO;
        }

        if (device_count == 0) {
                snd_portman_unregister_all();
                return -ENODEV;
        }

        return 0;
}

static void __exit snd_portman_module_exit(void)
{
        snd_portman_unregister_all();
}

module_init(snd_portman_module_init);
module_exit(snd_portman_module_exit);