/*
 * cpia_pp CPiA Parallel Port driver
 *
 * Supports CPiA based parallel port Video Camera's.
 *
 * (C) Copyright 1999 Bas Huisman <bhuism@cs.utwente.nl>
 * (C) Copyright 1999-2000 Scott J. Bertin <sbertin@securenym.net>,
 * (C) Copyright 1999-2000 Peter Pregler <Peter_Pregler@email.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.
 */

/* define _CPIA_DEBUG_ for verbose debug output (see cpia.h) */
/* #define _CPIA_DEBUG_  1 */


#include <linux/module.h>
#include <linux/init.h>

#include <linux/kernel.h>
#include <linux/parport.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/sched.h>

#include <linux/kmod.h>

/* #define _CPIA_DEBUG_         define for verbose debug output */
#include "cpia.h"

static int cpia_pp_open(void *privdata);
static int cpia_pp_registerCallback(void *privdata, void (*cb) (void *cbdata),
                                    void *cbdata);
static int cpia_pp_transferCmd(void *privdata, u8 *command, u8 *data);
static int cpia_pp_streamStart(void *privdata);
static int cpia_pp_streamStop(void *privdata);
static int cpia_pp_streamRead(void *privdata, u8 *buffer, int noblock);
static int cpia_pp_close(void *privdata);


#define ABOUT "Parallel port driver for Vision CPiA based cameras"

#define PACKET_LENGTH  8

/* Magic numbers for defining port-device mappings */
#define PPCPIA_PARPORT_UNSPEC -4
#define PPCPIA_PARPORT_AUTO -3
#define PPCPIA_PARPORT_OFF -2
#define PPCPIA_PARPORT_NONE -1

static int parport_nr[PARPORT_MAX] = {[0 ... PARPORT_MAX - 1] = PPCPIA_PARPORT_UNSPEC};
static char *parport[PARPORT_MAX] = {NULL,};

MODULE_AUTHOR("B. Huisman <bhuism@cs.utwente.nl> & Peter Pregler <Peter_Pregler@email.com>");
MODULE_DESCRIPTION("Parallel port driver for Vision CPiA based cameras");
MODULE_LICENSE("GPL");

module_param_array(parport, charp, NULL, 0);
MODULE_PARM_DESC(parport, "'auto' or a list of parallel port numbers. Just like lp.");

struct pp_cam_entry {
        struct pardevice *pdev;
        struct parport *port;
        struct work_struct cb_task;
        void (*cb_func)(void *cbdata);
        void *cb_data;
        int open_count;
        wait_queue_head_t wq_stream;
        /* image state flags */
        int image_ready;        /* we got an interrupt */
        int image_complete;     /* we have seen 4 EOI */

        int streaming; /* we are in streaming mode */
        int stream_irq;
};

static struct cpia_camera_ops cpia_pp_ops =
{
        cpia_pp_open,
        cpia_pp_registerCallback,
        cpia_pp_transferCmd,
        cpia_pp_streamStart,
        cpia_pp_streamStop,
        cpia_pp_streamRead,
        cpia_pp_close,
        1,
        THIS_MODULE
};

static LIST_HEAD(cam_list);
static spinlock_t cam_list_lock_pp;

/* FIXME */
static void cpia_parport_enable_irq( struct parport *port ) {
        parport_enable_irq(port);
        mdelay(10);
        return;
}

static void cpia_parport_disable_irq( struct parport *port ) {
        parport_disable_irq(port);
        mdelay(10);
        return;
}

/* Special CPiA PPC modes: These are invoked by using the 1284 Extensibility
 * Link Flag during negotiation */
#define UPLOAD_FLAG  0x08
#define NIBBLE_TRANSFER 0x01
#define ECP_TRANSFER 0x03

#define PARPORT_CHUNK_SIZE      PAGE_SIZE


static void cpia_pp_run_callback(struct work_struct *work)
{
        void (*cb_func)(void *cbdata);
        void *cb_data;
        struct pp_cam_entry *cam;

        cam = container_of(work, struct pp_cam_entry, cb_task);
        cb_func = cam->cb_func;
        cb_data = cam->cb_data;

        cb_func(cb_data);
}

/****************************************************************************
 *
 *  CPiA-specific  low-level parport functions for nibble uploads
 *
 ***************************************************************************/
/*  CPiA nonstandard "Nibble" mode (no nDataAvail signal after each byte). */
/* The standard kernel parport_ieee1284_read_nibble() fails with the CPiA... */

static size_t cpia_read_nibble (struct parport *port,
                         void *buffer, size_t len,
                         int flags)
{
        /* adapted verbatim, with one change, from
           parport_ieee1284_read_nibble() in drivers/parport/ieee1284-ops.c */

        unsigned char *buf = buffer;
        int i;
        unsigned char byte = 0;

        len *= 2; /* in nibbles */
        for (i=0; i < len; i++) {
                unsigned char nibble;

                /* The CPiA firmware suppresses the use of nDataAvail (nFault LO)
                 * after every second nibble to signal that more
                 * data is available.  (the total number of Bytes that
                 * should be sent is known; if too few are received, an error
                 * will be recorded after a timeout).
                 * This is incompatible with parport_ieee1284_read_nibble(),
                 * which expects to find nFault LO after every second nibble.
                 */

                /* Solution: modify cpia_read_nibble to only check for
                 * nDataAvail before the first nibble is sent.
                 */

                /* Does the error line indicate end of data? */
                if (((i /*& 1*/) == 0) &&
                    (parport_read_status(port) & PARPORT_STATUS_ERROR)) {
                        DBG("%s: No more nibble data (%d bytes)\n",
                            port->name, i/2);
                        goto end_of_data;
                }

                /* Event 7: Set nAutoFd low. */
                parport_frob_control (port,
                                      PARPORT_CONTROL_AUTOFD,
                                      PARPORT_CONTROL_AUTOFD);

                /* Event 9: nAck goes low. */
                port->ieee1284.phase = IEEE1284_PH_REV_DATA;
                if (parport_wait_peripheral (port,
                                             PARPORT_STATUS_ACK, 0)) {
                        /* Timeout -- no more data? */
                                 DBG("%s: Nibble timeout at event 9 (%d bytes)\n",
                                 port->name, i/2);
                        parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);
                        break;
                }


                /* Read a nibble. */
                nibble = parport_read_status (port) >> 3;
                nibble &= ~8;
                if ((nibble & 0x10) == 0)
                        nibble |= 8;
                nibble &= 0xf;

                /* Event 10: Set nAutoFd high. */
                parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);

                /* Event 11: nAck goes high. */
                if (parport_wait_peripheral (port,
                                             PARPORT_STATUS_ACK,
                                             PARPORT_STATUS_ACK)) {
                        /* Timeout -- no more data? */
                        DBG("%s: Nibble timeout at event 11\n",
                                 port->name);
                        break;
                }

                if (i & 1) {
                        /* Second nibble */
                        byte |= nibble << 4;
                        *buf++ = byte;
                } else
                        byte = nibble;
        }

        if (i == len) {
                /* Read the last nibble without checking data avail. */
                if (parport_read_status (port) & PARPORT_STATUS_ERROR) {
                end_of_data:
                        /* Go to reverse idle phase. */
                        parport_frob_control (port,
                                              PARPORT_CONTROL_AUTOFD,
                                              PARPORT_CONTROL_AUTOFD);
                        port->physport->ieee1284.phase = IEEE1284_PH_REV_IDLE;
                }
                else
                        port->physport->ieee1284.phase = IEEE1284_PH_HBUSY_DAVAIL;
        }

        return i/2;
}

/* CPiA nonstandard "Nibble Stream" mode (2 nibbles per cycle, instead of 1)
 * (See CPiA Data sheet p. 31)
 *
 * "Nibble Stream" mode used by CPiA for uploads to non-ECP ports is a
 * nonstandard variant of nibble mode which allows the same (mediocre)
 * data flow of 8 bits per cycle as software-enabled ECP by TRISTATE-capable
 * parallel ports, but works also for  non-TRISTATE-capable ports.
 * (Standard nibble mode only send 4 bits per cycle)
 *
 */

static size_t cpia_read_nibble_stream(struct parport *port,
                               void *buffer, size_t len,
                               int flags)
{
        int i;
        unsigned char *buf = buffer;
        int endseen = 0;

        for (i=0; i < len; i++) {
                unsigned char nibble[2], byte = 0;
                int j;

                /* Image Data is complete when 4 consecutive EOI bytes (0xff) are seen */
                if (endseen > 3 )
                        break;

                /* Event 7: Set nAutoFd low. */
                parport_frob_control (port,
                                      PARPORT_CONTROL_AUTOFD,
                                      PARPORT_CONTROL_AUTOFD);

                /* Event 9: nAck goes low. */
                port->ieee1284.phase = IEEE1284_PH_REV_DATA;
                if (parport_wait_peripheral (port,
                                             PARPORT_STATUS_ACK, 0)) {
                        /* Timeout -- no more data? */
                                 DBG("%s: Nibble timeout at event 9 (%d bytes)\n",
                                 port->name, i/2);
                        parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);
                        break;
                }

                /* Read lower nibble */
                nibble[0] = parport_read_status (port) >>3;

                /* Event 10: Set nAutoFd high. */
                parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);

                /* Event 11: nAck goes high. */
                if (parport_wait_peripheral (port,
                                             PARPORT_STATUS_ACK,
                                             PARPORT_STATUS_ACK)) {
                        /* Timeout -- no more data? */
                        DBG("%s: Nibble timeout at event 11\n",
                                 port->name);
                        break;
                }

                /* Read upper nibble */
                nibble[1] = parport_read_status (port) >>3;

                /* reassemble the byte */
                for (j = 0; j < 2 ; j++ ) {
                        nibble[j] &= ~8;
                        if ((nibble[j] & 0x10) == 0)
                                nibble[j] |= 8;
                        nibble[j] &= 0xf;
                }
                byte = (nibble[0] |(nibble[1] << 4));
                *buf++ = byte;

                if(byte == EOI)
                  endseen++;
                else
                  endseen = 0;
        }
        return i;
}

/****************************************************************************
 *
 *  EndTransferMode
 *
 ***************************************************************************/
static void EndTransferMode(struct pp_cam_entry *cam)
{
        parport_negotiate(cam->port, IEEE1284_MODE_COMPAT);
}

/****************************************************************************
 *
 *  ForwardSetup
 *
 ***************************************************************************/
static int ForwardSetup(struct pp_cam_entry *cam)
{
        int retry;

        /* The CPiA uses ECP protocol for Downloads from the Host to the camera.
         * This will be software-emulated if ECP hardware is not present
         */

        /* the usual camera maximum response time is 10ms, but after receiving
         * some commands, it needs up to 40ms. (Data Sheet p. 32)*/

        for(retry = 0; retry < 4; ++retry) {
                if(!parport_negotiate(cam->port, IEEE1284_MODE_ECP)) {
                        break;
                }
                mdelay(10);
        }
        if(retry == 4) {
                DBG("Unable to negotiate IEEE1284 ECP Download mode\n");
                return -1;
        }
        return 0;
}
/****************************************************************************
 *
 *  ReverseSetup
 *
 ***************************************************************************/
static int ReverseSetup(struct pp_cam_entry *cam, int extensibility)
{
        int retry;
        int upload_mode, mode = IEEE1284_MODE_ECP;
        int transfer_mode = ECP_TRANSFER;

        if (!(cam->port->modes & PARPORT_MODE_ECP) &&
             !(cam->port->modes & PARPORT_MODE_TRISTATE)) {
                mode = IEEE1284_MODE_NIBBLE;
                transfer_mode = NIBBLE_TRANSFER;
        }

        upload_mode = mode;
        if(extensibility) mode = UPLOAD_FLAG|transfer_mode|IEEE1284_EXT_LINK;

        /* the usual camera maximum response time is 10ms, but after
         * receiving some commands, it needs up to 40ms. */

        for(retry = 0; retry < 4; ++retry) {
                if(!parport_negotiate(cam->port, mode)) {
                        break;
                }
                mdelay(10);
        }
        if(retry == 4) {
                if(extensibility)
                        DBG("Unable to negotiate upload extensibility mode\n");
                else
                        DBG("Unable to negotiate upload mode\n");
                return -1;
        }
        if(extensibility) cam->port->ieee1284.mode = upload_mode;
        return 0;
}

/****************************************************************************
 *
 *  WritePacket
 *
 ***************************************************************************/
static int WritePacket(struct pp_cam_entry *cam, const u8 *packet, size_t size)
{
        int retval=0;
        int size_written;

        if (packet == NULL) {
                return -EINVAL;
        }
        if (ForwardSetup(cam)) {
                DBG("Write failed in setup\n");
                return -EIO;
        }
        size_written = parport_write(cam->port, packet, size);
        if(size_written != size) {
                DBG("Write failed, wrote %d/%d\n", size_written, size);
                retval = -EIO;
        }
        EndTransferMode(cam);
        return retval;
}

/****************************************************************************
 *
 *  ReadPacket
 *
 ***************************************************************************/
static int ReadPacket(struct pp_cam_entry *cam, u8 *packet, size_t size)
{
        int retval=0;

        if (packet == NULL) {
                return -EINVAL;
        }
        if (ReverseSetup(cam, 0)) {
                return -EIO;
        }

        /* support for CPiA variant nibble reads */
        if(cam->port->ieee1284.mode == IEEE1284_MODE_NIBBLE) {
                if(cpia_read_nibble(cam->port, packet, size, 0) != size)
                        retval = -EIO;
        } else {
                if(parport_read(cam->port, packet, size) != size)
                        retval = -EIO;
        }
        EndTransferMode(cam);
        return retval;
}

/****************************************************************************
 *
 *  cpia_pp_streamStart
 *
 ***************************************************************************/
static int cpia_pp_streamStart(void *privdata)
{
        struct pp_cam_entry *cam = privdata;
        DBG("\n");
        cam->streaming=1;
        cam->image_ready=0;
        //if (ReverseSetup(cam,1)) return -EIO;
        if(cam->stream_irq) cpia_parport_enable_irq(cam->port);
        return 0;
}

/****************************************************************************
 *
 *  cpia_pp_streamStop
 *
 ***************************************************************************/
static int cpia_pp_streamStop(void *privdata)
{
        struct pp_cam_entry *cam = privdata;

        DBG("\n");
        cam->streaming=0;
        cpia_parport_disable_irq(cam->port);
        //EndTransferMode(cam);

        return 0;
}

/****************************************************************************
 *
 *  cpia_pp_streamRead
 *
 ***************************************************************************/
static int cpia_pp_read(struct parport *port, u8 *buffer, int len)
{
        int bytes_read;

        /* support for CPiA variant "nibble stream" reads */
        if(port->ieee1284.mode == IEEE1284_MODE_NIBBLE)
                bytes_read = cpia_read_nibble_stream(port,buffer,len,0);
        else {
                int new_bytes;
                for(bytes_read=0; bytes_read<len; bytes_read += new_bytes) {
                        new_bytes = parport_read(port, buffer+bytes_read,
                                                 len-bytes_read);
                        if(new_bytes < 0) break;
                }
        }
        return bytes_read;
}

static int cpia_pp_streamRead(void *privdata, u8 *buffer, int noblock)
{
        struct pp_cam_entry *cam = privdata;
        int read_bytes = 0;
        int i, endseen, block_size, new_bytes;

        if(cam == NULL) {
                DBG("Internal driver error: cam is NULL\n");
                return -EINVAL;
        }
        if(buffer == NULL) {
                DBG("Internal driver error: buffer is NULL\n");
                return -EINVAL;
        }
        //if(cam->streaming) DBG("%d / %d\n", cam->image_ready, noblock);
        if( cam->stream_irq ) {
                DBG("%d\n", cam->image_ready);
                cam->image_ready--;
        }
        cam->image_complete=0;
        if (0/*cam->streaming*/) {
                if(!cam->image_ready) {
                        if(noblock) return -EWOULDBLOCK;
                        interruptible_sleep_on(&cam->wq_stream);
                        if( signal_pending(current) ) return -EINTR;
                        DBG("%d\n", cam->image_ready);
                }
        } else {
                if (ReverseSetup(cam, 1)) {
                        DBG("unable to ReverseSetup\n");
                        return -EIO;
                }
        }
        endseen = 0;
        block_size = PARPORT_CHUNK_SIZE;
        while( !cam->image_complete ) {
                cond_resched();

                new_bytes = cpia_pp_read(cam->port, buffer, block_size );
                if( new_bytes <= 0 ) {
                        break;
                }
                i=-1;
                while(++i<new_bytes && endseen<4) {
                        if(*buffer==EOI) {
                                endseen++;
                        } else {
                                endseen=0;
                        }
                        buffer++;
                }
                read_bytes += i;
                if( endseen==4 ) {
                        cam->image_complete=1;
                        break;
                }
                if( CPIA_MAX_IMAGE_SIZE-read_bytes <= PARPORT_CHUNK_SIZE ) {
                        block_size=CPIA_MAX_IMAGE_SIZE-read_bytes;
                }
        }
        EndTransferMode(cam);
        return cam->image_complete ? read_bytes : -EIO;
}
/****************************************************************************
 *
 *  cpia_pp_transferCmd
 *
 ***************************************************************************/
static int cpia_pp_transferCmd(void *privdata, u8 *command, u8 *data)
{
        int err;
        int retval=0;
        int databytes;
        struct pp_cam_entry *cam = privdata;

        if(cam == NULL) {
                DBG("Internal driver error: cam is NULL\n");
                return -EINVAL;
        }
        if(command == NULL) {
                DBG("Internal driver error: command is NULL\n");
                return -EINVAL;
        }
        databytes = (((int)command[7])<<8) | command[6];
        if ((err = WritePacket(cam, command, PACKET_LENGTH)) < 0) {
                DBG("Error writing command\n");
                return err;
        }
        if(command[0] == DATA_IN) {
                u8 buffer[8];
                if(data == NULL) {
                        DBG("Internal driver error: data is NULL\n");
                        return -EINVAL;
                }
                if((err = ReadPacket(cam, buffer, 8)) < 0) {
                        DBG("Error reading command result\n");
                       return err;
                }
                memcpy(data, buffer, databytes);
        } else if(command[0] == DATA_OUT) {
                if(databytes > 0) {
                        if(data == NULL) {
                                DBG("Internal driver error: data is NULL\n");
                                retval = -EINVAL;
                        } else {
                                if((err=WritePacket(cam, data, databytes)) < 0){
                                        DBG("Error writing command data\n");
                                        return err;
                                }
                        }
                }
        } else {
                DBG("Unexpected first byte of command: %x\n", command[0]);
                retval = -EINVAL;
        }
        return retval;
}

/****************************************************************************
 *
 *  cpia_pp_open
 *
 ***************************************************************************/
static int cpia_pp_open(void *privdata)
{
        struct pp_cam_entry *cam = (struct pp_cam_entry *)privdata;

        if (cam == NULL)
                return -EINVAL;

        if(cam->open_count == 0) {
                if (parport_claim(cam->pdev)) {
                        DBG("failed to claim the port\n");
                        return -EBUSY;
                }
                parport_negotiate(cam->port, IEEE1284_MODE_COMPAT);
                parport_data_forward(cam->port);
                parport_write_control(cam->port, PARPORT_CONTROL_SELECT);
                udelay(50);
                parport_write_control(cam->port,
                                      PARPORT_CONTROL_SELECT
                                      | PARPORT_CONTROL_INIT);
        }

        ++cam->open_count;

        return 0;
}

/****************************************************************************
 *
 *  cpia_pp_registerCallback
 *
 ***************************************************************************/
static int cpia_pp_registerCallback(void *privdata, void (*cb)(void *cbdata), void *cbdata)
{
        struct pp_cam_entry *cam = privdata;
        int retval = 0;

        if(cam->port->irq != PARPORT_IRQ_NONE) {
                cam->cb_func = cb;
                cam->cb_data = cbdata;
                INIT_WORK(&cam->cb_task, cpia_pp_run_callback);
        } else {
                retval = -1;
        }
        return retval;
}

/****************************************************************************
 *
 *  cpia_pp_close
 *
 ***************************************************************************/
static int cpia_pp_close(void *privdata)
{
        struct pp_cam_entry *cam = privdata;
        if (--cam->open_count == 0) {
                parport_release(cam->pdev);
        }
        return 0;
}

/****************************************************************************
 *
 *  cpia_pp_register
 *
 ***************************************************************************/
static int cpia_pp_register(struct parport *port)
{
        struct pardevice *pdev = NULL;
        struct pp_cam_entry *cam;
        struct cam_data *cpia;

        if (!(port->modes & PARPORT_MODE_PCSPP)) {
                LOG("port is not supported by CPiA driver\n");
                return -ENXIO;
        }

        cam = kzalloc(sizeof(struct pp_cam_entry), GFP_KERNEL);
        if (cam == NULL) {
                LOG("failed to allocate camera structure\n");
                return -ENOMEM;
        }

        pdev = parport_register_device(port, "cpia_pp", NULL, NULL,
                                       NULL, 0, cam);

        if (!pdev) {
                LOG("failed to parport_register_device\n");
                kfree(cam);
                return -ENXIO;
        }

        cam->pdev = pdev;
        cam->port = port;
        init_waitqueue_head(&cam->wq_stream);

        cam->streaming = 0;
        cam->stream_irq = 0;

        if((cpia = cpia_register_camera(&cpia_pp_ops, cam)) == NULL) {
                LOG("failed to cpia_register_camera\n");
                parport_unregister_device(pdev);
                kfree(cam);
                return -ENXIO;
        }
        spin_lock( &cam_list_lock_pp );
        list_add( &cpia->cam_data_list, &cam_list );
        spin_unlock( &cam_list_lock_pp );

        return 0;
}

static void cpia_pp_detach (struct parport *port)
{
        struct list_head *tmp;
        struct cam_data *cpia = NULL;
        struct pp_cam_entry *cam;

        spin_lock( &cam_list_lock_pp );
        list_for_each (tmp, &cam_list) {
                cpia = list_entry(tmp, struct cam_data, cam_data_list);
                cam = (struct pp_cam_entry *) cpia->lowlevel_data;
                if (cam && cam->port->number == port->number) {
                        list_del(&cpia->cam_data_list);
                        break;
                }
                cpia = NULL;
        }
        spin_unlock( &cam_list_lock_pp );

        if (!cpia) {
                DBG("cpia_pp_detach failed to find cam_data in cam_list\n");
                return;
        }

        cam = (struct pp_cam_entry *) cpia->lowlevel_data;
        cpia_unregister_camera(cpia);
        if(cam->open_count > 0)
                cpia_pp_close(cam);
        parport_unregister_device(cam->pdev);
        cpia->lowlevel_data = NULL;
        kfree(cam);
}

static void cpia_pp_attach (struct parport *port)
{
        unsigned int i;

        switch (parport_nr[0])
        {
        case PPCPIA_PARPORT_UNSPEC:
        case PPCPIA_PARPORT_AUTO:
                if (port->probe_info[0].class != PARPORT_CLASS_MEDIA ||
                    port->probe_info[0].cmdset == NULL ||
                    strncmp(port->probe_info[0].cmdset, "CPIA_1", 6) != 0)
                        return;

                cpia_pp_register(port);

                break;

        default:
                for (i = 0; i < PARPORT_MAX; ++i) {
                        if (port->number == parport_nr[i]) {
                                cpia_pp_register(port);
                                break;
                        }
                }
                break;
        }
}

static struct parport_driver cpia_pp_driver = {
        .name = "cpia_pp",
        .attach = cpia_pp_attach,
        .detach = cpia_pp_detach,
};

static int __init cpia_pp_init(void)
{
        printk(KERN_INFO "%s v%d.%d.%d\n",ABOUT,
               CPIA_PP_MAJ_VER,CPIA_PP_MIN_VER,CPIA_PP_PATCH_VER);

        if(parport_nr[0] == PPCPIA_PARPORT_OFF) {
                printk("  disabled\n");
                return 0;
        }

        spin_lock_init( &cam_list_lock_pp );

        if (parport_register_driver (&cpia_pp_driver)) {
                LOG ("unable to register with parport\n");
                return -EIO;
        }
        return 0;
}

static int __init cpia_init(void)
{
        if (parport[0]) {
                /* The user gave some parameters.  Let's see what they were. */
                if (!strncmp(parport[0], "auto", 4)) {
                        parport_nr[0] = PPCPIA_PARPORT_AUTO;
                } else {
                        int n;
                        for (n = 0; n < PARPORT_MAX && parport[n]; n++) {
                                if (!strncmp(parport[n], "none", 4)) {
                                        parport_nr[n] = PPCPIA_PARPORT_NONE;
                                } else {
                                        char *ep;
                                        unsigned long r = simple_strtoul(parport[n], &ep, 0);
                                        if (ep != parport[n]) {
                                                parport_nr[n] = r;
                                        } else {
                                                LOG("bad port specifier `%s'\n", parport[n]);
                                                return -ENODEV;
                                        }
                                }
                        }
                }
        }
        return cpia_pp_init();
}

static void __exit cpia_cleanup(void)
{
        parport_unregister_driver(&cpia_pp_driver);
        return;
}

module_init(cpia_init);
module_exit(cpia_cleanup);