zr364xx.c

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/*
 * Zoran 364xx based USB webcam module version 0.73
 *
 * Allows you to use your USB webcam with V4L2 applications
 * This is still in heavy developpement !
 *
 * Copyright (C) 2004  Antoine Jacquet <[email protected]>
 * http://royale.zerezo.com/zr364xx/
 *
 * Heavily inspired by usb-skeleton.c, vicam.c, cpia.c and spca50x.c drivers
 * V4L2 version inspired by meye.c driver
 *
 * Some video buffer code by Lamarque based on s2255drv.c and vivi.c drivers.
 *
 * 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
 */


#include <linux/module.h>
#include <linux/init.h>
#include <linux/usb.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/highmem.h>
#include <media/v4l2-common.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>
#include <media/videobuf-vmalloc.h>


/* Version Information */
#define DRIVER_VERSION "0.7.4"
#define DRIVER_AUTHOR "Antoine Jacquet, http://royale.zerezo.com/"
#define DRIVER_DESC "Zoran 364xx"


/* Camera */
#define FRAMES 1
#define MAX_FRAME_SIZE 200000
#define BUFFER_SIZE 0x1000
#define CTRL_TIMEOUT 500

#define ZR364XX_DEF_BUFS    4
#define ZR364XX_READ_IDLE   0
#define ZR364XX_READ_FRAME  1

/* Debug macro */
#define DBG(fmt, args...) \
    do { \
        if (debug) { \
            printk(KERN_INFO KBUILD_MODNAME " " fmt, ##args); \
        } \
    } while (0)

/*#define FULL_DEBUG 1*/
#ifdef FULL_DEBUG
#define _DBG DBG
#else
#define _DBG(fmt, args...)
#endif

/* Init methods, need to find nicer names for these
 * the exact names of the chipsets would be the best if someone finds it */
#define METHOD0 0
#define METHOD1 1
#define METHOD2 2
#define METHOD3 3


/* Module parameters */
static int debug;
static int mode;


/* Module parameters interface */
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Debug level");
module_param(mode, int, 0644);
MODULE_PARM_DESC(mode, "0 = 320x240, 1 = 160x120, 2 = 640x480");


/* Devices supported by this driver
 * .driver_info contains the init method used by the camera */
static struct usb_device_id device_table[] = {
    {USB_DEVICE(0x08ca, 0x0109), .driver_info = METHOD0 },
    {USB_DEVICE(0x041e, 0x4024), .driver_info = METHOD0 },
    {USB_DEVICE(0x0d64, 0x0108), .driver_info = METHOD0 },
    {USB_DEVICE(0x0546, 0x3187), .driver_info = METHOD0 },
    {USB_DEVICE(0x0d64, 0x3108), .driver_info = METHOD0 },
    {USB_DEVICE(0x0595, 0x4343), .driver_info = METHOD0 },
    {USB_DEVICE(0x0bb0, 0x500d), .driver_info = METHOD0 },
    {USB_DEVICE(0x0feb, 0x2004), .driver_info = METHOD0 },
    {USB_DEVICE(0x055f, 0xb500), .driver_info = METHOD0 },
    {USB_DEVICE(0x08ca, 0x2062), .driver_info = METHOD2 },
    {USB_DEVICE(0x052b, 0x1a18), .driver_info = METHOD1 },
    {USB_DEVICE(0x04c8, 0x0729), .driver_info = METHOD0 },
    {USB_DEVICE(0x04f2, 0xa208), .driver_info = METHOD0 },
    {USB_DEVICE(0x0784, 0x0040), .driver_info = METHOD1 },
    {USB_DEVICE(0x06d6, 0x0034), .driver_info = METHOD0 },
    {USB_DEVICE(0x0a17, 0x0062), .driver_info = METHOD2 },
    {USB_DEVICE(0x06d6, 0x003b), .driver_info = METHOD0 },
    {USB_DEVICE(0x0a17, 0x004e), .driver_info = METHOD2 },
    {USB_DEVICE(0x041e, 0x405d), .driver_info = METHOD2 },
    {USB_DEVICE(0x08ca, 0x2102), .driver_info = METHOD3 },
    {USB_DEVICE(0x06d6, 0x003d), .driver_info = METHOD0 },
    {}          /* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, device_table);

/* frame structure */
struct zr364xx_framei {
    unsigned long ulState;  /* ulState:ZR364XX_READ_IDLE,
                       ZR364XX_READ_FRAME */
    void *lpvbits;      /* image data */
    unsigned long cur_size; /* current data copied to it */
};

/* image buffer structure */
struct zr364xx_bufferi {
    unsigned long dwFrames;         /* number of frames in buffer */
    struct zr364xx_framei frame[FRAMES];    /* array of FRAME structures */
};

struct zr364xx_dmaqueue {
    struct list_head    active;
    struct zr364xx_camera   *cam;
};

struct zr364xx_pipeinfo {
    u32 transfer_size;
    u8 *transfer_buffer;
    u32 state;
    void *stream_urb;
    void *cam;  /* back pointer to zr364xx_camera struct */
    u32 err_count;
    u32 idx;
};

struct zr364xx_fmt {
    char *name;
    u32 fourcc;
    int depth;
};

/* image formats.  */
static const struct zr364xx_fmt formats[] = {
    {
        .name = "JPG",
        .fourcc = V4L2_PIX_FMT_JPEG,
        .depth = 24
    }
};

/* Camera stuff */
struct zr364xx_camera {
    struct usb_device *udev;    /* save off the usb device pointer */
    struct usb_interface *interface;/* the interface for this device */
    struct v4l2_device v4l2_dev;
    struct v4l2_ctrl_handler ctrl_handler;
    struct video_device vdev;   /* v4l video device */
    struct v4l2_fh *owner;      /* owns the streaming */
    int nb;
    struct zr364xx_bufferi      buffer;
    int skip;
    int width;
    int height;
    int method;
    struct mutex lock;

    spinlock_t      slock;
    struct zr364xx_dmaqueue vidq;
    int         last_frame;
    int         cur_frame;
    unsigned long       frame_count;
    int         b_acquire;
    struct zr364xx_pipeinfo pipe[1];

    u8          read_endpoint;

    const struct zr364xx_fmt *fmt;
    struct videobuf_queue   vb_vidq;
    bool was_streaming;
};

/* buffer for one video frame */
struct zr364xx_buffer {
    /* common v4l buffer stuff -- must be first */
    struct videobuf_buffer vb;
    const struct zr364xx_fmt *fmt;
};

/* function used to send initialisation commands to the camera */
static int send_control_msg(struct usb_device *udev, u8 request, u16 value,
                u16 index, unsigned char *cp, u16 size)
{
    int status;

    unsigned char *transfer_buffer = kmalloc(size, GFP_KERNEL);
    if (!transfer_buffer) {
        dev_err(&udev->dev, "kmalloc(%d) failed\n", size);
        return -ENOMEM;
    }

    memcpy(transfer_buffer, cp, size);

    status = usb_control_msg(udev,
                 usb_sndctrlpipe(udev, 0),
                 request,
                 USB_DIR_OUT | USB_TYPE_VENDOR |
                 USB_RECIP_DEVICE, value, index,
                 transfer_buffer, size, CTRL_TIMEOUT);

    kfree(transfer_buffer);
    return status;
}


/* Control messages sent to the camera to initialize it
 * and launch the capture */
typedef struct {
    unsigned int value;
    unsigned int size;
    unsigned char *bytes;
} message;

/* method 0 */
static unsigned char m0d1[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
static unsigned char m0d2[] = { 0, 0, 0, 0, 0, 0 };
static unsigned char m0d3[] = { 0, 0 };
static message m0[] = {
    {0x1f30, 0, NULL},
    {0xd000, 0, NULL},
    {0x3370, sizeof(m0d1), m0d1},
    {0x2000, 0, NULL},
    {0x2f0f, 0, NULL},
    {0x2610, sizeof(m0d2), m0d2},
    {0xe107, 0, NULL},
    {0x2502, 0, NULL},
    {0x1f70, 0, NULL},
    {0xd000, 0, NULL},
    {0x9a01, sizeof(m0d3), m0d3},
    {-1, -1, NULL}
};

/* method 1 */
static unsigned char m1d1[] = { 0xff, 0xff };
static unsigned char m1d2[] = { 0x00, 0x00 };
static message m1[] = {
    {0x1f30, 0, NULL},
    {0xd000, 0, NULL},
    {0xf000, 0, NULL},
    {0x2000, 0, NULL},
    {0x2f0f, 0, NULL},
    {0x2650, 0, NULL},
    {0xe107, 0, NULL},
    {0x2502, sizeof(m1d1), m1d1},
    {0x1f70, 0, NULL},
    {0xd000, 0, NULL},
    {0xd000, 0, NULL},
    {0xd000, 0, NULL},
    {0x9a01, sizeof(m1d2), m1d2},
    {-1, -1, NULL}
};

/* method 2 */
static unsigned char m2d1[] = { 0xff, 0xff };
static message m2[] = {
    {0x1f30, 0, NULL},
    {0xf000, 0, NULL},
    {0x2000, 0, NULL},
    {0x2f0f, 0, NULL},
    {0x2650, 0, NULL},
    {0xe107, 0, NULL},
    {0x2502, sizeof(m2d1), m2d1},
    {0x1f70, 0, NULL},
    {-1, -1, NULL}
};

/* init table */
static message *init[4] = { m0, m1, m2, m2 };


/* JPEG static data in header (Huffman table, etc) */
static unsigned char header1[] = {
    0xFF, 0xD8,
    /*
    0xFF, 0xE0, 0x00, 0x10, 'J', 'F', 'I', 'F',
    0x00, 0x01, 0x01, 0x00, 0x33, 0x8A, 0x00, 0x00, 0x33, 0x88,
    */
    0xFF, 0xDB, 0x00, 0x84
};
static unsigned char header2[] = {
    0xFF, 0xC4, 0x00, 0x1F, 0x00, 0x00, 0x01, 0x05, 0x01, 0x01, 0x01,
    0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B,
    0xFF, 0xC4, 0x00, 0xB5, 0x10, 0x00, 0x02, 0x01, 0x03, 0x03, 0x02,
    0x04, 0x03, 0x05, 0x05, 0x04, 0x04, 0x00, 0x00, 0x01, 0x7D, 0x01,
    0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, 0x21, 0x31, 0x41, 0x06,
    0x13, 0x51, 0x61, 0x07, 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xA1,
    0x08, 0x23, 0x42, 0xB1, 0xC1, 0x15, 0x52, 0xD1, 0xF0, 0x24, 0x33,
    0x62, 0x72, 0x82, 0x09, 0x0A, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x25,
    0x26, 0x27, 0x28, 0x29, 0x2A, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
    0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x53, 0x54,
    0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67,
    0x68, 0x69, 0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A,
    0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x92, 0x93, 0x94,
    0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6,
    0xA7, 0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8,
    0xB9, 0xBA, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA,
    0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xE1, 0xE2,
    0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xF1, 0xF2, 0xF3,
    0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFF, 0xC4, 0x00, 0x1F,
    0x01, 0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
    0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04,
    0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0xFF, 0xC4, 0x00, 0xB5,
    0x11, 0x00, 0x02, 0x01, 0x02, 0x04, 0x04, 0x03, 0x04, 0x07, 0x05,
    0x04, 0x04, 0x00, 0x01, 0x02, 0x77, 0x00, 0x01, 0x02, 0x03, 0x11,
    0x04, 0x05, 0x21, 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
    0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, 0xA1, 0xB1, 0xC1,
    0x09, 0x23, 0x33, 0x52, 0xF0, 0x15, 0x62, 0x72, 0xD1, 0x0A, 0x16,
    0x24, 0x34, 0xE1, 0x25, 0xF1, 0x17, 0x18, 0x19, 0x1A, 0x26, 0x27,
    0x28, 0x29, 0x2A, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x43, 0x44,
    0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x53, 0x54, 0x55, 0x56, 0x57,
    0x58, 0x59, 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A,
    0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x82, 0x83, 0x84,
    0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96,
    0x97, 0x98, 0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8,
    0xA9, 0xAA, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA,
    0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2, 0xD3,
    0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xE2, 0xE3, 0xE4, 0xE5,
    0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
    0xF8, 0xF9, 0xFA, 0xFF, 0xC0, 0x00, 0x11, 0x08, 0x00, 0xF0, 0x01,
    0x40, 0x03, 0x01, 0x21, 0x00, 0x02, 0x11, 0x01, 0x03, 0x11, 0x01,
    0xFF, 0xDA, 0x00, 0x0C, 0x03, 0x01, 0x00, 0x02, 0x11, 0x03, 0x11,
    0x00, 0x3F, 0x00
};
static unsigned char header3;

/* ------------------------------------------------------------------
   Videobuf operations
   ------------------------------------------------------------------*/

static int buffer_setup(struct videobuf_queue *vq, unsigned int *count,
            unsigned int *size)
{
    struct zr364xx_camera *cam = vq->priv_data;

    *size = cam->width * cam->height * (cam->fmt->depth >> 3);

    if (*count == 0)
        *count = ZR364XX_DEF_BUFS;

    if (*size * *count > ZR364XX_DEF_BUFS * 1024 * 1024)
        *count = (ZR364XX_DEF_BUFS * 1024 * 1024) / *size;

    return 0;
}

static void free_buffer(struct videobuf_queue *vq, struct zr364xx_buffer *buf)
{
    _DBG("%s\n", __func__);

    if (in_interrupt())
        BUG();

    videobuf_vmalloc_free(&buf->vb);
    buf->vb.state = VIDEOBUF_NEEDS_INIT;
}

static int buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,
              enum v4l2_field field)
{
    struct zr364xx_camera *cam = vq->priv_data;
    struct zr364xx_buffer *buf = container_of(vb, struct zr364xx_buffer,
                          vb);
    int rc;

    DBG("%s, field=%d, fmt name = %s\n", __func__, field, cam->fmt != NULL ?
        cam->fmt->name : "");
    if (cam->fmt == NULL)
        return -EINVAL;

    buf->vb.size = cam->width * cam->height * (cam->fmt->depth >> 3);

    if (buf->vb.baddr != 0 && buf->vb.bsize < buf->vb.size) {
        DBG("invalid buffer prepare\n");
        return -EINVAL;
    }

    buf->fmt = cam->fmt;
    buf->vb.width = cam->width;
    buf->vb.height = cam->height;
    buf->vb.field = field;

    if (buf->vb.state == VIDEOBUF_NEEDS_INIT) {
        rc = videobuf_iolock(vq, &buf->vb, NULL);
        if (rc < 0)
            goto fail;
    }

    buf->vb.state = VIDEOBUF_PREPARED;
    return 0;
fail:
    free_buffer(vq, buf);
    return rc;
}

static void buffer_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
{
    struct zr364xx_buffer *buf = container_of(vb, struct zr364xx_buffer,
                          vb);
    struct zr364xx_camera *cam = vq->priv_data;

    _DBG("%s\n", __func__);

    buf->vb.state = VIDEOBUF_QUEUED;
    list_add_tail(&buf->vb.queue, &cam->vidq.active);
}

static void buffer_release(struct videobuf_queue *vq,
               struct videobuf_buffer *vb)
{
    struct zr364xx_buffer *buf = container_of(vb, struct zr364xx_buffer,
                          vb);

    _DBG("%s\n", __func__);
    free_buffer(vq, buf);
}

static struct videobuf_queue_ops zr364xx_video_qops = {
    .buf_setup = buffer_setup,
    .buf_prepare = buffer_prepare,
    .buf_queue = buffer_queue,
    .buf_release = buffer_release,
};

/********************/
/* V4L2 integration */
/********************/
static int zr364xx_vidioc_streamon(struct file *file, void *priv,
                   enum v4l2_buf_type type);

static ssize_t zr364xx_read(struct file *file, char __user *buf, size_t count,
                loff_t * ppos)
{
    struct zr364xx_camera *cam = video_drvdata(file);
    int err = 0;

    _DBG("%s\n", __func__);

    if (!buf)
        return -EINVAL;

    if (!count)
        return -EINVAL;

    if (mutex_lock_interruptible(&cam->lock))
        return -ERESTARTSYS;

    err = zr364xx_vidioc_streamon(file, file->private_data,
                V4L2_BUF_TYPE_VIDEO_CAPTURE);
    if (err == 0) {
        DBG("%s: reading %d bytes at pos %d.\n", __func__,
                (int) count, (int) *ppos);

        /* NoMan Sux ! */
        err = videobuf_read_one(&cam->vb_vidq, buf, count, ppos,
                    file->f_flags & O_NONBLOCK);
    }
    mutex_unlock(&cam->lock);
    return err;
}

/* video buffer vmalloc implementation based partly on VIVI driver which is
 *          Copyright (c) 2006 by
 *                  Mauro Carvalho Chehab <mchehab--a.t--infradead.org>
 *                  Ted Walther <ted--a.t--enumera.com>
 *                  John Sokol <sokol--a.t--videotechnology.com>
 *                  http://v4l.videotechnology.com/
 *
 */
static void zr364xx_fillbuff(struct zr364xx_camera *cam,
                 struct zr364xx_buffer *buf,
                 int jpgsize)
{
    int pos = 0;
    struct timeval ts;
    const char *tmpbuf;
    char *vbuf = videobuf_to_vmalloc(&buf->vb);
    unsigned long last_frame;

    if (!vbuf)
        return;

    last_frame = cam->last_frame;
    if (last_frame != -1) {
        tmpbuf = (const char *)cam->buffer.frame[last_frame].lpvbits;
        switch (buf->fmt->fourcc) {
        case V4L2_PIX_FMT_JPEG:
            buf->vb.size = jpgsize;
            memcpy(vbuf, tmpbuf, buf->vb.size);
            break;
        default:
            printk(KERN_DEBUG KBUILD_MODNAME ": unknown format?\n");
        }
        cam->last_frame = -1;
    } else {
        printk(KERN_ERR KBUILD_MODNAME ": =======no frame\n");
        return;
    }
    DBG("%s: Buffer 0x%08lx size= %d\n", __func__,
        (unsigned long)vbuf, pos);
    /* tell v4l buffer was filled */

    buf->vb.field_count = cam->frame_count * 2;
    do_gettimeofday(&ts);
    buf->vb.ts = ts;
    buf->vb.state = VIDEOBUF_DONE;
}

static int zr364xx_got_frame(struct zr364xx_camera *cam, int jpgsize)
{
    struct zr364xx_dmaqueue *dma_q = &cam->vidq;
    struct zr364xx_buffer *buf;
    unsigned long flags = 0;
    int rc = 0;

    DBG("wakeup: %p\n", &dma_q);
    spin_lock_irqsave(&cam->slock, flags);

    if (list_empty(&dma_q->active)) {
        DBG("No active queue to serve\n");
        rc = -1;
        goto unlock;
    }
    buf = list_entry(dma_q->active.next,
             struct zr364xx_buffer, vb.queue);

    if (!waitqueue_active(&buf->vb.done)) {
        /* no one active */
        rc = -1;
        goto unlock;
    }
    list_del(&buf->vb.queue);
    do_gettimeofday(&buf->vb.ts);
    DBG("[%p/%d] wakeup\n", buf, buf->vb.i);
    zr364xx_fillbuff(cam, buf, jpgsize);
    wake_up(&buf->vb.done);
    DBG("wakeup [buf/i] [%p/%d]\n", buf, buf->vb.i);
unlock:
    spin_unlock_irqrestore(&cam->slock, flags);
    return rc;
}

/* this function moves the usb stream read pipe data
 * into the system buffers.
 * returns 0 on success, EAGAIN if more data to process (call this
 * function again).
 */
static int zr364xx_read_video_callback(struct zr364xx_camera *cam,
                    struct zr364xx_pipeinfo *pipe_info,
                    struct urb *purb)
{
    unsigned char *pdest;
    unsigned char *psrc;
    s32 idx = -1;
    struct zr364xx_framei *frm;
    int i = 0;
    unsigned char *ptr = NULL;

    _DBG("buffer to user\n");
    idx = cam->cur_frame;
    frm = &cam->buffer.frame[idx];

    /* swap bytes if camera needs it */
    if (cam->method == METHOD0) {
        u16 *buf = (u16 *)pipe_info->transfer_buffer;
        for (i = 0; i < purb->actual_length/2; i++)
            swab16s(buf + i);
    }

    /* search done.  now find out if should be acquiring */
    if (!cam->b_acquire) {
        /* we found a frame, but this channel is turned off */
        frm->ulState = ZR364XX_READ_IDLE;
        return -EINVAL;
    }

    psrc = (u8 *)pipe_info->transfer_buffer;
    ptr = pdest = frm->lpvbits;

    if (frm->ulState == ZR364XX_READ_IDLE) {
        frm->ulState = ZR364XX_READ_FRAME;
        frm->cur_size = 0;

        _DBG("jpeg header, ");
        memcpy(ptr, header1, sizeof(header1));
        ptr += sizeof(header1);
        header3 = 0;
        memcpy(ptr, &header3, 1);
        ptr++;
        memcpy(ptr, psrc, 64);
        ptr += 64;
        header3 = 1;
        memcpy(ptr, &header3, 1);
        ptr++;
        memcpy(ptr, psrc + 64, 64);
        ptr += 64;
        memcpy(ptr, header2, sizeof(header2));
        ptr += sizeof(header2);
        memcpy(ptr, psrc + 128,
               purb->actual_length - 128);
        ptr += purb->actual_length - 128;
        _DBG("header : %d %d %d %d %d %d %d %d %d\n",
            psrc[0], psrc[1], psrc[2],
            psrc[3], psrc[4], psrc[5],
            psrc[6], psrc[7], psrc[8]);
        frm->cur_size = ptr - pdest;
    } else {
        if (frm->cur_size + purb->actual_length > MAX_FRAME_SIZE) {
            dev_info(&cam->udev->dev,
                 "%s: buffer (%d bytes) too small to hold "
                 "frame data. Discarding frame data.\n",
                 __func__, MAX_FRAME_SIZE);
        } else {
            pdest += frm->cur_size;
            memcpy(pdest, psrc, purb->actual_length);
            frm->cur_size += purb->actual_length;
        }
    }
    /*_DBG("cur_size %lu urb size %d\n", frm->cur_size,
        purb->actual_length);*/

    if (purb->actual_length < pipe_info->transfer_size) {
        _DBG("****************Buffer[%d]full*************\n", idx);
        cam->last_frame = cam->cur_frame;
        cam->cur_frame++;
        /* end of system frame ring buffer, start at zero */
        if (cam->cur_frame == cam->buffer.dwFrames)
            cam->cur_frame = 0;

        /* frame ready */
        /* go back to find the JPEG EOI marker */
        ptr = pdest = frm->lpvbits;
        ptr += frm->cur_size - 2;
        while (ptr > pdest) {
            if (*ptr == 0xFF && *(ptr + 1) == 0xD9
                && *(ptr + 2) == 0xFF)
                break;
            ptr--;
        }
        if (ptr == pdest)
            DBG("No EOI marker\n");

        /* Sometimes there is junk data in the middle of the picture,
         * we want to skip this bogus frames */
        while (ptr > pdest) {
            if (*ptr == 0xFF && *(ptr + 1) == 0xFF
                && *(ptr + 2) == 0xFF)
                break;
            ptr--;
        }
        if (ptr != pdest) {
            DBG("Bogus frame ? %d\n", ++(cam->nb));
        } else if (cam->b_acquire) {
            /* we skip the 2 first frames which are usually buggy */
            if (cam->skip)
                cam->skip--;
            else {
                _DBG("jpeg(%lu): %d %d %d %d %d %d %d %d\n",
                    frm->cur_size,
                    pdest[0], pdest[1], pdest[2], pdest[3],
                    pdest[4], pdest[5], pdest[6], pdest[7]);

                zr364xx_got_frame(cam, frm->cur_size);
            }
        }
        cam->frame_count++;
        frm->ulState = ZR364XX_READ_IDLE;
        frm->cur_size = 0;
    }
    /* done successfully */
    return 0;
}

static int zr364xx_vidioc_querycap(struct file *file, void *priv,
                   struct v4l2_capability *cap)
{
    struct zr364xx_camera *cam = video_drvdata(file);

    strlcpy(cap->driver, DRIVER_DESC, sizeof(cap->driver));
    strlcpy(cap->card, cam->udev->product, sizeof(cap->card));
    strlcpy(cap->bus_info, dev_name(&cam->udev->dev),
        sizeof(cap->bus_info));
    cap->device_caps = V4L2_CAP_VIDEO_CAPTURE |
                V4L2_CAP_READWRITE |
                V4L2_CAP_STREAMING;
    cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;

    return 0;
}

static int zr364xx_vidioc_enum_input(struct file *file, void *priv,
                     struct v4l2_input *i)
{
    if (i->index != 0)
        return -EINVAL;
    strcpy(i->name, DRIVER_DESC " Camera");
    i->type = V4L2_INPUT_TYPE_CAMERA;
    return 0;
}

static int zr364xx_vidioc_g_input(struct file *file, void *priv,
                  unsigned int *i)
{
    *i = 0;
    return 0;
}

static int zr364xx_vidioc_s_input(struct file *file, void *priv,
                  unsigned int i)
{
    if (i != 0)
        return -EINVAL;
    return 0;
}

static int zr364xx_s_ctrl(struct v4l2_ctrl *ctrl)
{
    struct zr364xx_camera *cam =
        container_of(ctrl->handler, struct zr364xx_camera, ctrl_handler);
    int temp;

    switch (ctrl->id) {
    case V4L2_CID_BRIGHTNESS:
        /* hardware brightness */
        send_control_msg(cam->udev, 1, 0x2001, 0, NULL, 0);
        temp = (0x60 << 8) + 127 - ctrl->val;
        send_control_msg(cam->udev, 1, temp, 0, NULL, 0);
        break;
    default:
        return -EINVAL;
    }

    return 0;
}

static int zr364xx_vidioc_enum_fmt_vid_cap(struct file *file,
                       void *priv, struct v4l2_fmtdesc *f)
{
    if (f->index > 0)
        return -EINVAL;
    f->flags = V4L2_FMT_FLAG_COMPRESSED;
    strcpy(f->description, formats[0].name);
    f->pixelformat = formats[0].fourcc;
    return 0;
}

static char *decode_fourcc(__u32 pixelformat, char *buf)
{
    buf[0] = pixelformat & 0xff;
    buf[1] = (pixelformat >> 8) & 0xff;
    buf[2] = (pixelformat >> 16) & 0xff;
    buf[3] = (pixelformat >> 24) & 0xff;
    buf[4] = '\0';
    return buf;
}

static int zr364xx_vidioc_try_fmt_vid_cap(struct file *file, void *priv,
                      struct v4l2_format *f)
{
    struct zr364xx_camera *cam = video_drvdata(file);
    char pixelformat_name[5];

    if (cam == NULL)
        return -ENODEV;

    if (f->fmt.pix.pixelformat != V4L2_PIX_FMT_JPEG) {
        DBG("%s: unsupported pixelformat V4L2_PIX_FMT_%s\n", __func__,
            decode_fourcc(f->fmt.pix.pixelformat, pixelformat_name));
        return -EINVAL;
    }

    if (!(f->fmt.pix.width == 160 && f->fmt.pix.height == 120) &&
        !(f->fmt.pix.width == 640 && f->fmt.pix.height == 480)) {
        f->fmt.pix.width = 320;
        f->fmt.pix.height = 240;
    }

    f->fmt.pix.field = V4L2_FIELD_NONE;
    f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
    f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
    f->fmt.pix.colorspace = V4L2_COLORSPACE_JPEG;
    f->fmt.pix.priv = 0;
    DBG("%s: V4L2_PIX_FMT_%s (%d) ok!\n", __func__,
        decode_fourcc(f->fmt.pix.pixelformat, pixelformat_name),
        f->fmt.pix.field);
    return 0;
}

static int zr364xx_vidioc_g_fmt_vid_cap(struct file *file, void *priv,
                    struct v4l2_format *f)
{
    struct zr364xx_camera *cam;

    if (file == NULL)
        return -ENODEV;
    cam = video_drvdata(file);

    f->fmt.pix.pixelformat = formats[0].fourcc;
    f->fmt.pix.field = V4L2_FIELD_NONE;
    f->fmt.pix.width = cam->width;
    f->fmt.pix.height = cam->height;
    f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
    f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
    f->fmt.pix.colorspace = V4L2_COLORSPACE_JPEG;
    f->fmt.pix.priv = 0;
    return 0;
}

static int zr364xx_vidioc_s_fmt_vid_cap(struct file *file, void *priv,
                    struct v4l2_format *f)
{
    struct zr364xx_camera *cam = video_drvdata(file);
    struct videobuf_queue *q = &cam->vb_vidq;
    char pixelformat_name[5];
    int ret = zr364xx_vidioc_try_fmt_vid_cap(file, cam, f);
    int i;

    if (ret < 0)
        return ret;

    mutex_lock(&q->vb_lock);

    if (videobuf_queue_is_busy(&cam->vb_vidq)) {
        DBG("%s queue busy\n", __func__);
        ret = -EBUSY;
        goto out;
    }

    if (cam->owner) {
        DBG("%s can't change format after started\n", __func__);
        ret = -EBUSY;
        goto out;
    }

    cam->width = f->fmt.pix.width;
    cam->height = f->fmt.pix.height;
    DBG("%s: %dx%d mode selected\n", __func__,
         cam->width, cam->height);
    f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
    f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;
    f->fmt.pix.colorspace = V4L2_COLORSPACE_JPEG;
    f->fmt.pix.priv = 0;
    cam->vb_vidq.field = f->fmt.pix.field;

    if (f->fmt.pix.width == 160 && f->fmt.pix.height == 120)
        mode = 1;
    else if (f->fmt.pix.width == 640 && f->fmt.pix.height == 480)
        mode = 2;
    else
        mode = 0;

    m0d1[0] = mode;
    m1[2].value = 0xf000 + mode;
    m2[1].value = 0xf000 + mode;

    /* special case for METHOD3, the modes are different */
    if (cam->method == METHOD3) {
        switch (mode) {
        case 1:
            m2[1].value = 0xf000 + 4;
            break;
        case 2:
            m2[1].value = 0xf000 + 0;
            break;
        default:
            m2[1].value = 0xf000 + 1;
            break;
        }
    }

    header2[437] = cam->height / 256;
    header2[438] = cam->height % 256;
    header2[439] = cam->width / 256;
    header2[440] = cam->width % 256;

    for (i = 0; init[cam->method][i].size != -1; i++) {
        ret =
            send_control_msg(cam->udev, 1, init[cam->method][i].value,
                     0, init[cam->method][i].bytes,
                     init[cam->method][i].size);
        if (ret < 0) {
            dev_err(&cam->udev->dev,
               "error during resolution change sequence: %d\n", i);
            goto out;
        }
    }

    /* Added some delay here, since opening/closing the camera quickly,
     * like Ekiga does during its startup, can crash the webcam
     */
    mdelay(100);
    cam->skip = 2;
    ret = 0;

out:
    mutex_unlock(&q->vb_lock);

    DBG("%s: V4L2_PIX_FMT_%s (%d) ok!\n", __func__,
        decode_fourcc(f->fmt.pix.pixelformat, pixelformat_name),
        f->fmt.pix.field);
    return ret;
}

static int zr364xx_vidioc_reqbufs(struct file *file, void *priv,
              struct v4l2_requestbuffers *p)
{
    struct zr364xx_camera *cam = video_drvdata(file);

    if (cam->owner && cam->owner != priv)
        return -EBUSY;
    return videobuf_reqbufs(&cam->vb_vidq, p);
}

static int zr364xx_vidioc_querybuf(struct file *file,
                void *priv,
                struct v4l2_buffer *p)
{
    int rc;
    struct zr364xx_camera *cam = video_drvdata(file);
    rc = videobuf_querybuf(&cam->vb_vidq, p);
    return rc;
}

static int zr364xx_vidioc_qbuf(struct file *file,
                void *priv,
                struct v4l2_buffer *p)
{
    int rc;
    struct zr364xx_camera *cam = video_drvdata(file);
    _DBG("%s\n", __func__);
    if (cam->owner && cam->owner != priv)
        return -EBUSY;
    rc = videobuf_qbuf(&cam->vb_vidq, p);
    return rc;
}

static int zr364xx_vidioc_dqbuf(struct file *file,
                void *priv,
                struct v4l2_buffer *p)
{
    int rc;
    struct zr364xx_camera *cam = video_drvdata(file);
    _DBG("%s\n", __func__);
    if (cam->owner && cam->owner != priv)
        return -EBUSY;
    rc = videobuf_dqbuf(&cam->vb_vidq, p, file->f_flags & O_NONBLOCK);
    return rc;
}

static void read_pipe_completion(struct urb *purb)
{
    struct zr364xx_pipeinfo *pipe_info;
    struct zr364xx_camera *cam;
    int pipe;

    pipe_info = purb->context;
    _DBG("%s %p, status %d\n", __func__, purb, purb->status);
    if (pipe_info == NULL) {
        printk(KERN_ERR KBUILD_MODNAME ": no context!\n");
        return;
    }

    cam = pipe_info->cam;
    if (cam == NULL) {
        printk(KERN_ERR KBUILD_MODNAME ": no context!\n");
        return;
    }

    /* if shutting down, do not resubmit, exit immediately */
    if (purb->status == -ESHUTDOWN) {
        DBG("%s, err shutdown\n", __func__);
        pipe_info->err_count++;
        return;
    }

    if (pipe_info->state == 0) {
        DBG("exiting USB pipe\n");
        return;
    }

    if (purb->actual_length < 0 ||
        purb->actual_length > pipe_info->transfer_size) {
        dev_err(&cam->udev->dev, "wrong number of bytes\n");
        return;
    }

    if (purb->status == 0)
        zr364xx_read_video_callback(cam, pipe_info, purb);
    else {
        pipe_info->err_count++;
        DBG("%s: failed URB %d\n", __func__, purb->status);
    }

    pipe = usb_rcvbulkpipe(cam->udev, cam->read_endpoint);

    /* reuse urb */
    usb_fill_bulk_urb(pipe_info->stream_urb, cam->udev,
              pipe,
              pipe_info->transfer_buffer,
              pipe_info->transfer_size,
              read_pipe_completion, pipe_info);

    if (pipe_info->state != 0) {
        purb->status = usb_submit_urb(pipe_info->stream_urb,
                          GFP_ATOMIC);

        if (purb->status)
            dev_err(&cam->udev->dev,
                "error submitting urb (error=%i)\n",
                purb->status);
    } else
        DBG("read pipe complete state 0\n");
}

static int zr364xx_start_readpipe(struct zr364xx_camera *cam)
{
    int pipe;
    int retval;
    struct zr364xx_pipeinfo *pipe_info = cam->pipe;
    pipe = usb_rcvbulkpipe(cam->udev, cam->read_endpoint);
    DBG("%s: start pipe IN x%x\n", __func__, cam->read_endpoint);

    pipe_info->state = 1;
    pipe_info->err_count = 0;
    pipe_info->stream_urb = usb_alloc_urb(0, GFP_KERNEL);
    if (!pipe_info->stream_urb) {
        dev_err(&cam->udev->dev, "ReadStream: Unable to alloc URB\n");
        return -ENOMEM;
    }
    /* transfer buffer allocated in board_init */
    usb_fill_bulk_urb(pipe_info->stream_urb, cam->udev,
              pipe,
              pipe_info->transfer_buffer,
              pipe_info->transfer_size,
              read_pipe_completion, pipe_info);

    DBG("submitting URB %p\n", pipe_info->stream_urb);
    retval = usb_submit_urb(pipe_info->stream_urb, GFP_KERNEL);
    if (retval) {
        printk(KERN_ERR KBUILD_MODNAME ": start read pipe failed\n");
        return retval;
    }

    return 0;
}

static void zr364xx_stop_readpipe(struct zr364xx_camera *cam)
{
    struct zr364xx_pipeinfo *pipe_info;

    if (cam == NULL) {
        printk(KERN_ERR KBUILD_MODNAME ": invalid device\n");
        return;
    }
    DBG("stop read pipe\n");
    pipe_info = cam->pipe;
    if (pipe_info) {
        if (pipe_info->state != 0)
            pipe_info->state = 0;

        if (pipe_info->stream_urb) {
            /* cancel urb */
            usb_kill_urb(pipe_info->stream_urb);
            usb_free_urb(pipe_info->stream_urb);
            pipe_info->stream_urb = NULL;
        }
    }
    return;
}

/* starts acquisition process */
static int zr364xx_start_acquire(struct zr364xx_camera *cam)
{
    int j;

    DBG("start acquire\n");

    cam->last_frame = -1;
    cam->cur_frame = 0;
    for (j = 0; j < FRAMES; j++) {
        cam->buffer.frame[j].ulState = ZR364XX_READ_IDLE;
        cam->buffer.frame[j].cur_size = 0;
    }
    cam->b_acquire = 1;
    return 0;
}

static inline int zr364xx_stop_acquire(struct zr364xx_camera *cam)
{
    cam->b_acquire = 0;
    return 0;
}

static int zr364xx_prepare(struct zr364xx_camera *cam)
{
    int res;
    int i, j;

    for (i = 0; init[cam->method][i].size != -1; i++) {
        res = send_control_msg(cam->udev, 1, init[cam->method][i].value,
                     0, init[cam->method][i].bytes,
                     init[cam->method][i].size);
        if (res < 0) {
            dev_err(&cam->udev->dev,
                "error during open sequence: %d\n", i);
            return res;
        }
    }

    cam->skip = 2;
    cam->last_frame = -1;
    cam->cur_frame = 0;
    cam->frame_count = 0;
    for (j = 0; j < FRAMES; j++) {
        cam->buffer.frame[j].ulState = ZR364XX_READ_IDLE;
        cam->buffer.frame[j].cur_size = 0;
    }
    v4l2_ctrl_handler_setup(&cam->ctrl_handler);
    return 0;
}

static int zr364xx_vidioc_streamon(struct file *file, void *priv,
                   enum v4l2_buf_type type)
{
    struct zr364xx_camera *cam = video_drvdata(file);
    int res;

    DBG("%s\n", __func__);

    if (type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
        return -EINVAL;

    if (cam->owner && cam->owner != priv)
        return -EBUSY;

    res = zr364xx_prepare(cam);
    if (res)
        return res;
    res = videobuf_streamon(&cam->vb_vidq);
    if (res == 0) {
        zr364xx_start_acquire(cam);
        cam->owner = file->private_data;
    }
    return res;
}

static int zr364xx_vidioc_streamoff(struct file *file, void *priv,
                    enum v4l2_buf_type type)
{
    struct zr364xx_camera *cam = video_drvdata(file);

    DBG("%s\n", __func__);
    if (type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
        return -EINVAL;
    if (cam->owner && cam->owner != priv)
        return -EBUSY;
    zr364xx_stop_acquire(cam);
    return videobuf_streamoff(&cam->vb_vidq);
}


/* open the camera */
static int zr364xx_open(struct file *file)
{
    struct zr364xx_camera *cam = video_drvdata(file);
    int err;

    DBG("%s\n", __func__);

    if (mutex_lock_interruptible(&cam->lock))
        return -ERESTARTSYS;

    err = v4l2_fh_open(file);
    if (err)
        goto out;

    /* Added some delay here, since opening/closing the camera quickly,
     * like Ekiga does during its startup, can crash the webcam
     */
    mdelay(100);
    err = 0;

out:
    mutex_unlock(&cam->lock);
    DBG("%s: %d\n", __func__, err);
    return err;
}

static void zr364xx_release(struct v4l2_device *v4l2_dev)
{
    struct zr364xx_camera *cam =
        container_of(v4l2_dev, struct zr364xx_camera, v4l2_dev);
    unsigned long i;

    v4l2_device_unregister(&cam->v4l2_dev);

    videobuf_mmap_free(&cam->vb_vidq);

    /* release sys buffers */
    for (i = 0; i < FRAMES; i++) {
        if (cam->buffer.frame[i].lpvbits) {
            DBG("vfree %p\n", cam->buffer.frame[i].lpvbits);
            vfree(cam->buffer.frame[i].lpvbits);
        }
        cam->buffer.frame[i].lpvbits = NULL;
    }

    v4l2_ctrl_handler_free(&cam->ctrl_handler);
    /* release transfer buffer */
    kfree(cam->pipe->transfer_buffer);
    kfree(cam);
}

/* release the camera */
static int zr364xx_close(struct file *file)
{
    struct zr364xx_camera *cam;
    struct usb_device *udev;
    int i;

    DBG("%s\n", __func__);
    cam = video_drvdata(file);

    mutex_lock(&cam->lock);
    udev = cam->udev;

    if (file->private_data == cam->owner) {
        /* turn off stream */
        if (cam->b_acquire)
            zr364xx_stop_acquire(cam);
        videobuf_streamoff(&cam->vb_vidq);

        for (i = 0; i < 2; i++) {
            send_control_msg(udev, 1, init[cam->method][i].value,
                    0, init[cam->method][i].bytes,
                    init[cam->method][i].size);
        }
        cam->owner = NULL;
    }

    /* Added some delay here, since opening/closing the camera quickly,
     * like Ekiga does during its startup, can crash the webcam
     */
    mdelay(100);
    mutex_unlock(&cam->lock);
    return v4l2_fh_release(file);
}


static int zr364xx_mmap(struct file *file, struct vm_area_struct *vma)
{
    struct zr364xx_camera *cam = video_drvdata(file);
    int ret;

    if (cam == NULL) {
        DBG("%s: cam == NULL\n", __func__);
        return -ENODEV;
    }
    DBG("mmap called, vma=0x%08lx\n", (unsigned long)vma);

    ret = videobuf_mmap_mapper(&cam->vb_vidq, vma);

    DBG("vma start=0x%08lx, size=%ld, ret=%d\n",
        (unsigned long)vma->vm_start,
        (unsigned long)vma->vm_end - (unsigned long)vma->vm_start, ret);
    return ret;
}

static unsigned int zr364xx_poll(struct file *file,
                   struct poll_table_struct *wait)
{
    struct zr364xx_camera *cam = video_drvdata(file);
    struct videobuf_queue *q = &cam->vb_vidq;
    unsigned res = v4l2_ctrl_poll(file, wait);

    _DBG("%s\n", __func__);

    return res | videobuf_poll_stream(file, q, wait);
}

static const struct v4l2_ctrl_ops zr364xx_ctrl_ops = {
    .s_ctrl = zr364xx_s_ctrl,
};

static const struct v4l2_file_operations zr364xx_fops = {
    .owner = THIS_MODULE,
    .open = zr364xx_open,
    .release = zr364xx_close,
    .read = zr364xx_read,
    .mmap = zr364xx_mmap,
    .unlocked_ioctl = video_ioctl2,
    .poll = zr364xx_poll,
};

static const struct v4l2_ioctl_ops zr364xx_ioctl_ops = {
    .vidioc_querycap    = zr364xx_vidioc_querycap,
    .vidioc_enum_fmt_vid_cap = zr364xx_vidioc_enum_fmt_vid_cap,
    .vidioc_try_fmt_vid_cap = zr364xx_vidioc_try_fmt_vid_cap,
    .vidioc_s_fmt_vid_cap   = zr364xx_vidioc_s_fmt_vid_cap,
    .vidioc_g_fmt_vid_cap   = zr364xx_vidioc_g_fmt_vid_cap,
    .vidioc_enum_input  = zr364xx_vidioc_enum_input,
    .vidioc_g_input     = zr364xx_vidioc_g_input,
    .vidioc_s_input     = zr364xx_vidioc_s_input,
    .vidioc_streamon    = zr364xx_vidioc_streamon,
    .vidioc_streamoff   = zr364xx_vidioc_streamoff,
    .vidioc_reqbufs         = zr364xx_vidioc_reqbufs,
    .vidioc_querybuf        = zr364xx_vidioc_querybuf,
    .vidioc_qbuf            = zr364xx_vidioc_qbuf,
    .vidioc_dqbuf           = zr364xx_vidioc_dqbuf,
    .vidioc_log_status      = v4l2_ctrl_log_status,
    .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
    .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static struct video_device zr364xx_template = {
    .name = DRIVER_DESC,
    .fops = &zr364xx_fops,
    .ioctl_ops = &zr364xx_ioctl_ops,
    .release = video_device_release_empty,
};



/*******************/
/* USB integration */
/*******************/
static int zr364xx_board_init(struct zr364xx_camera *cam)
{
    struct zr364xx_pipeinfo *pipe = cam->pipe;
    unsigned long i;

    DBG("board init: %p\n", cam);
    memset(pipe, 0, sizeof(*pipe));
    pipe->cam = cam;
    pipe->transfer_size = BUFFER_SIZE;

    pipe->transfer_buffer = kzalloc(pipe->transfer_size,
                    GFP_KERNEL);
    if (pipe->transfer_buffer == NULL) {
        DBG("out of memory!\n");
        return -ENOMEM;
    }

    cam->b_acquire = 0;
    cam->frame_count = 0;

    /*** start create system buffers ***/
    for (i = 0; i < FRAMES; i++) {
        /* always allocate maximum size for system buffers */
        cam->buffer.frame[i].lpvbits = vmalloc(MAX_FRAME_SIZE);

        DBG("valloc %p, idx %lu, pdata %p\n",
            &cam->buffer.frame[i], i,
            cam->buffer.frame[i].lpvbits);
        if (cam->buffer.frame[i].lpvbits == NULL) {
            printk(KERN_INFO KBUILD_MODNAME ": out of memory. "
                   "Using less frames\n");
            break;
        }
    }

    if (i == 0) {
        printk(KERN_INFO KBUILD_MODNAME ": out of memory. Aborting\n");
        kfree(cam->pipe->transfer_buffer);
        cam->pipe->transfer_buffer = NULL;
        return -ENOMEM;
    } else
        cam->buffer.dwFrames = i;

    /* make sure internal states are set */
    for (i = 0; i < FRAMES; i++) {
        cam->buffer.frame[i].ulState = ZR364XX_READ_IDLE;
        cam->buffer.frame[i].cur_size = 0;
    }

    cam->cur_frame = 0;
    cam->last_frame = -1;
    /*** end create system buffers ***/

    /* start read pipe */
    zr364xx_start_readpipe(cam);
    DBG(": board initialized\n");
    return 0;
}

static int zr364xx_probe(struct usb_interface *intf,
             const struct usb_device_id *id)
{
    struct usb_device *udev = interface_to_usbdev(intf);
    struct zr364xx_camera *cam = NULL;
    struct usb_host_interface *iface_desc;
    struct usb_endpoint_descriptor *endpoint;
    struct v4l2_ctrl_handler *hdl;
    int err;
    int i;

    DBG("probing...\n");

    dev_info(&intf->dev, DRIVER_DESC " compatible webcam plugged\n");
    dev_info(&intf->dev, "model %04x:%04x detected\n",
         le16_to_cpu(udev->descriptor.idVendor),
         le16_to_cpu(udev->descriptor.idProduct));

    cam = kzalloc(sizeof(struct zr364xx_camera), GFP_KERNEL);
    if (cam == NULL) {
        dev_err(&udev->dev, "cam: out of memory !\n");
        return -ENOMEM;
    }

    cam->v4l2_dev.release = zr364xx_release;
    err = v4l2_device_register(&intf->dev, &cam->v4l2_dev);
    if (err < 0) {
        dev_err(&udev->dev, "couldn't register v4l2_device\n");
        kfree(cam);
        return err;
    }
    hdl = &cam->ctrl_handler;
    v4l2_ctrl_handler_init(hdl, 1);
    v4l2_ctrl_new_std(hdl, &zr364xx_ctrl_ops,
              V4L2_CID_BRIGHTNESS, 0, 127, 1, 64);
    if (hdl->error) {
        err = hdl->error;
        dev_err(&udev->dev, "couldn't register control\n");
        goto fail;
    }
    /* save the init method used by this camera */
    cam->method = id->driver_info;
    mutex_init(&cam->lock);
    cam->vdev = zr364xx_template;
    cam->vdev.lock = &cam->lock;
    cam->vdev.v4l2_dev = &cam->v4l2_dev;
    cam->vdev.ctrl_handler = &cam->ctrl_handler;
    set_bit(V4L2_FL_USE_FH_PRIO, &cam->vdev.flags);
    video_set_drvdata(&cam->vdev, cam);
    if (debug)
        cam->vdev.debug = V4L2_DEBUG_IOCTL | V4L2_DEBUG_IOCTL_ARG;

    cam->udev = udev;

    switch (mode) {
    case 1:
        dev_info(&udev->dev, "160x120 mode selected\n");
        cam->width = 160;
        cam->height = 120;
        break;
    case 2:
        dev_info(&udev->dev, "640x480 mode selected\n");
        cam->width = 640;
        cam->height = 480;
        break;
    default:
        dev_info(&udev->dev, "320x240 mode selected\n");
        cam->width = 320;
        cam->height = 240;
        break;
    }

    m0d1[0] = mode;
    m1[2].value = 0xf000 + mode;
    m2[1].value = 0xf000 + mode;

    /* special case for METHOD3, the modes are different */
    if (cam->method == METHOD3) {
        switch (mode) {
        case 1:
            m2[1].value = 0xf000 + 4;
            break;
        case 2:
            m2[1].value = 0xf000 + 0;
            break;
        default:
            m2[1].value = 0xf000 + 1;
            break;
        }
    }

    header2[437] = cam->height / 256;
    header2[438] = cam->height % 256;
    header2[439] = cam->width / 256;
    header2[440] = cam->width % 256;

    cam->nb = 0;

    DBG("dev: %p, udev %p interface %p\n", cam, cam->udev, intf);

    /* set up the endpoint information  */
    iface_desc = intf->cur_altsetting;
    DBG("num endpoints %d\n", iface_desc->desc.bNumEndpoints);
    for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
        endpoint = &iface_desc->endpoint[i].desc;
        if (!cam->read_endpoint && usb_endpoint_is_bulk_in(endpoint)) {
            /* we found the bulk in endpoint */
            cam->read_endpoint = endpoint->bEndpointAddress;
        }
    }

    if (!cam->read_endpoint) {
        err = -ENOMEM;
        dev_err(&intf->dev, "Could not find bulk-in endpoint\n");
        goto fail;
    }

    /* v4l */
    INIT_LIST_HEAD(&cam->vidq.active);
    cam->vidq.cam = cam;

    usb_set_intfdata(intf, cam);

    /* load zr364xx board specific */
    err = zr364xx_board_init(cam);
    if (!err)
        err = v4l2_ctrl_handler_setup(hdl);
    if (err)
        goto fail;

    spin_lock_init(&cam->slock);

    cam->fmt = formats;

    videobuf_queue_vmalloc_init(&cam->vb_vidq, &zr364xx_video_qops,
                    NULL, &cam->slock,
                    V4L2_BUF_TYPE_VIDEO_CAPTURE,
                    V4L2_FIELD_NONE,
                    sizeof(struct zr364xx_buffer), cam, &cam->lock);

    err = video_register_device(&cam->vdev, VFL_TYPE_GRABBER, -1);
    if (err) {
        dev_err(&udev->dev, "video_register_device failed\n");
        goto fail;
    }

    dev_info(&udev->dev, DRIVER_DESC " controlling device %s\n",
         video_device_node_name(&cam->vdev));
    return 0;

fail:
    v4l2_ctrl_handler_free(hdl);
    v4l2_device_unregister(&cam->v4l2_dev);
    kfree(cam);
    return err;
}


static void zr364xx_disconnect(struct usb_interface *intf)
{
    struct zr364xx_camera *cam = usb_get_intfdata(intf);

    mutex_lock(&cam->lock);
    usb_set_intfdata(intf, NULL);
    dev_info(&intf->dev, DRIVER_DESC " webcam unplugged\n");
    video_unregister_device(&cam->vdev);
    v4l2_device_disconnect(&cam->v4l2_dev);

    /* stops the read pipe if it is running */
    if (cam->b_acquire)
        zr364xx_stop_acquire(cam);

    zr364xx_stop_readpipe(cam);
    mutex_unlock(&cam->lock);
    v4l2_device_put(&cam->v4l2_dev);
}


#ifdef CONFIG_PM
static int zr364xx_suspend(struct usb_interface *intf, pm_message_t message)
{
    struct zr364xx_camera *cam = usb_get_intfdata(intf);

    cam->was_streaming = cam->b_acquire;
    if (!cam->was_streaming)
        return 0;
    zr364xx_stop_acquire(cam);
    zr364xx_stop_readpipe(cam);
    return 0;
}

static int zr364xx_resume(struct usb_interface *intf)
{
    struct zr364xx_camera *cam = usb_get_intfdata(intf);
    int res;

    if (!cam->was_streaming)
        return 0;

    zr364xx_start_readpipe(cam);
    res = zr364xx_prepare(cam);
    if (!res)
        zr364xx_start_acquire(cam);
    return res;
}
#endif

/**********************/
/* Module integration */
/**********************/

static struct usb_driver zr364xx_driver = {
    .name = "zr364xx",
    .probe = zr364xx_probe,
    .disconnect = zr364xx_disconnect,
#ifdef CONFIG_PM
    .suspend = zr364xx_suspend,
    .resume = zr364xx_resume,
    .reset_resume = zr364xx_resume,
#endif
    .id_table = device_table
};

module_usb_driver(zr364xx_driver);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_VERSION(DRIVER_VERSION);