/*
 * Main USB camera driver
 *
 * Copyright (C) 2008-2011 Jean-François Moine <http://moinejf.free.fr>
 *
 * Camera button input handling by Márton Németh
 * Copyright (C) 2009-2010 Márton Németh <nm127@freemail.hu>
 *
 * 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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#define GSPCA_VERSION   "2.14.0"

#include <linux/init.h>
#include <linux/fs.h>
#include <linux/vmalloc.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/pagemap.h>
#include <linux/io.h>
#include <asm/page.h>
#include <linux/uaccess.h>
#include <linux/ktime.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>

#include "gspca.h"

#if IS_ENABLED(CONFIG_INPUT)
#include <linux/input.h>
#include <linux/usb/input.h>
#endif

/* global values */
#define DEF_NURBS 3             /* default number of URBs */
#if DEF_NURBS > MAX_NURBS
#error "DEF_NURBS too big"
#endif

MODULE_AUTHOR("Jean-François Moine <http://moinejf.free.fr>");
MODULE_DESCRIPTION("GSPCA USB Camera Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(GSPCA_VERSION);

int gspca_debug;
EXPORT_SYMBOL(gspca_debug);

static void PDEBUG_MODE(struct gspca_dev *gspca_dev, int debug, char *txt,
                        __u32 pixfmt, int w, int h)
{
        if ((pixfmt >> 24) >= '0' && (pixfmt >> 24) <= 'z') {
                PDEBUG(debug, "%s %c%c%c%c %dx%d",
                        txt,
                        pixfmt & 0xff,
                        (pixfmt >> 8) & 0xff,
                        (pixfmt >> 16) & 0xff,
                        pixfmt >> 24,
                        w, h);
        } else {
                PDEBUG(debug, "%s 0x%08x %dx%d",
                        txt,
                        pixfmt,
                        w, h);
        }
}

/* specific memory types - !! should be different from V4L2_MEMORY_xxx */
#define GSPCA_MEMORY_NO 0       /* V4L2_MEMORY_xxx starts from 1 */
#define GSPCA_MEMORY_READ 7

#define BUF_ALL_FLAGS (V4L2_BUF_FLAG_QUEUED | V4L2_BUF_FLAG_DONE)

/*
 * VMA operations.
 */
static void gspca_vm_open(struct vm_area_struct *vma)
{
        struct gspca_frame *frame = vma->vm_private_data;

        frame->vma_use_count++;
        frame->v4l2_buf.flags |= V4L2_BUF_FLAG_MAPPED;
}

static void gspca_vm_close(struct vm_area_struct *vma)
{
        struct gspca_frame *frame = vma->vm_private_data;

        if (--frame->vma_use_count <= 0)
                frame->v4l2_buf.flags &= ~V4L2_BUF_FLAG_MAPPED;
}

static const struct vm_operations_struct gspca_vm_ops = {
        .open           = gspca_vm_open,
        .close          = gspca_vm_close,
};

/*
 * Input and interrupt endpoint handling functions
 */
#if IS_ENABLED(CONFIG_INPUT)
static void int_irq(struct urb *urb)
{
        struct gspca_dev *gspca_dev = (struct gspca_dev *) urb->context;
        int ret;

        ret = urb->status;
        switch (ret) {
        case 0:
                if (gspca_dev->sd_desc->int_pkt_scan(gspca_dev,
                    urb->transfer_buffer, urb->actual_length) < 0) {
                        PERR("Unknown packet received");
                }
                break;

        case -ENOENT:
        case -ECONNRESET:
        case -ENODEV:
        case -ESHUTDOWN:
                /* Stop is requested either by software or hardware is gone,
                 * keep the ret value non-zero and don't resubmit later.
                 */
                break;

        default:
                PERR("URB error %i, resubmitting", urb->status);
                urb->status = 0;
                ret = 0;
        }

        if (ret == 0) {
                ret = usb_submit_urb(urb, GFP_ATOMIC);
                if (ret < 0)
                        pr_err("Resubmit URB failed with error %i\n", ret);
        }
}

static int gspca_input_connect(struct gspca_dev *dev)
{
        struct input_dev *input_dev;
        int err = 0;

        dev->input_dev = NULL;
        if (dev->sd_desc->int_pkt_scan || dev->sd_desc->other_input)  {
                input_dev = input_allocate_device();
                if (!input_dev)
                        return -ENOMEM;

                usb_make_path(dev->dev, dev->phys, sizeof(dev->phys));
                strlcat(dev->phys, "/input0", sizeof(dev->phys));

                input_dev->name = dev->sd_desc->name;
                input_dev->phys = dev->phys;

                usb_to_input_id(dev->dev, &input_dev->id);

                input_dev->evbit[0] = BIT_MASK(EV_KEY);
                input_dev->keybit[BIT_WORD(KEY_CAMERA)] = BIT_MASK(KEY_CAMERA);
                input_dev->dev.parent = &dev->dev->dev;

                err = input_register_device(input_dev);
                if (err) {
                        pr_err("Input device registration failed with error %i\n",
                               err);
                        input_dev->dev.parent = NULL;
                        input_free_device(input_dev);
                } else {
                        dev->input_dev = input_dev;
                }
        }

        return err;
}

static int alloc_and_submit_int_urb(struct gspca_dev *gspca_dev,
                          struct usb_endpoint_descriptor *ep)
{
        unsigned int buffer_len;
        int interval;
        struct urb *urb;
        struct usb_device *dev;
        void *buffer = NULL;
        int ret = -EINVAL;

        buffer_len = le16_to_cpu(ep->wMaxPacketSize);
        interval = ep->bInterval;
        PDEBUG(D_CONF, "found int in endpoint: 0x%x, "
                "buffer_len=%u, interval=%u",
                ep->bEndpointAddress, buffer_len, interval);

        dev = gspca_dev->dev;

        urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!urb) {
                ret = -ENOMEM;
                goto error;
        }

        buffer = usb_alloc_coherent(dev, buffer_len,
                                GFP_KERNEL, &urb->transfer_dma);
        if (!buffer) {
                ret = -ENOMEM;
                goto error_buffer;
        }
        usb_fill_int_urb(urb, dev,
                usb_rcvintpipe(dev, ep->bEndpointAddress),
                buffer, buffer_len,
                int_irq, (void *)gspca_dev, interval);
        urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
        ret = usb_submit_urb(urb, GFP_KERNEL);
        if (ret < 0) {
                PERR("submit int URB failed with error %i", ret);
                goto error_submit;
        }
        gspca_dev->int_urb = urb;
        return ret;

error_submit:
        usb_free_coherent(dev,
                          urb->transfer_buffer_length,
                          urb->transfer_buffer,
                          urb->transfer_dma);
error_buffer:
        usb_free_urb(urb);
error:
        return ret;
}

static void gspca_input_create_urb(struct gspca_dev *gspca_dev)
{
        struct usb_interface *intf;
        struct usb_host_interface *intf_desc;
        struct usb_endpoint_descriptor *ep;
        int i;

        if (gspca_dev->sd_desc->int_pkt_scan)  {
                intf = usb_ifnum_to_if(gspca_dev->dev, gspca_dev->iface);
                intf_desc = intf->cur_altsetting;
                for (i = 0; i < intf_desc->desc.bNumEndpoints; i++) {
                        ep = &intf_desc->endpoint[i].desc;
                        if (usb_endpoint_dir_in(ep) &&
                            usb_endpoint_xfer_int(ep)) {

                                alloc_and_submit_int_urb(gspca_dev, ep);
                                break;
                        }
                }
        }
}

static void gspca_input_destroy_urb(struct gspca_dev *gspca_dev)
{
        struct urb *urb;

        urb = gspca_dev->int_urb;
        if (urb) {
                gspca_dev->int_urb = NULL;
                usb_kill_urb(urb);
                usb_free_coherent(gspca_dev->dev,
                                  urb->transfer_buffer_length,
                                  urb->transfer_buffer,
                                  urb->transfer_dma);
                usb_free_urb(urb);
        }
}
#else
static inline void gspca_input_destroy_urb(struct gspca_dev *gspca_dev)
{
}

static inline void gspca_input_create_urb(struct gspca_dev *gspca_dev)
{
}

static inline int gspca_input_connect(struct gspca_dev *dev)
{
        return 0;
}
#endif

/*
 * fill a video frame from an URB and resubmit
 */
static void fill_frame(struct gspca_dev *gspca_dev,
                        struct urb *urb)
{
        u8 *data;               /* address of data in the iso message */
        int i, len, st;
        cam_pkt_op pkt_scan;

        if (urb->status != 0) {
                if (urb->status == -ESHUTDOWN)
                        return;         /* disconnection */
#ifdef CONFIG_PM
                if (gspca_dev->frozen)
                        return;
#endif
                PERR("urb status: %d", urb->status);
                urb->status = 0;
                goto resubmit;
        }
        pkt_scan = gspca_dev->sd_desc->pkt_scan;
        for (i = 0; i < urb->number_of_packets; i++) {
                len = urb->iso_frame_desc[i].actual_length;

                /* check the packet status and length */
                st = urb->iso_frame_desc[i].status;
                if (st) {
                        pr_err("ISOC data error: [%d] len=%d, status=%d\n",
                               i, len, st);
                        gspca_dev->last_packet_type = DISCARD_PACKET;
                        continue;
                }
                if (len == 0) {
                        if (gspca_dev->empty_packet == 0)
                                gspca_dev->empty_packet = 1;
                        continue;
                }

                /* let the packet be analyzed by the subdriver */
                PDEBUG(D_PACK, "packet [%d] o:%d l:%d",
                        i, urb->iso_frame_desc[i].offset, len);
                data = (u8 *) urb->transfer_buffer
                                        + urb->iso_frame_desc[i].offset;
                pkt_scan(gspca_dev, data, len);
        }

resubmit:
        /* resubmit the URB */
        st = usb_submit_urb(urb, GFP_ATOMIC);
        if (st < 0)
                pr_err("usb_submit_urb() ret %d\n", st);
}

/*
 * ISOC message interrupt from the USB device
 *
 * Analyse each packet and call the subdriver for copy to the frame buffer.
 */
static void isoc_irq(struct urb *urb)
{
        struct gspca_dev *gspca_dev = (struct gspca_dev *) urb->context;

        PDEBUG(D_PACK, "isoc irq");
        if (!gspca_dev->streaming)
                return;
        fill_frame(gspca_dev, urb);
}

/*
 * bulk message interrupt from the USB device
 */
static void bulk_irq(struct urb *urb)
{
        struct gspca_dev *gspca_dev = (struct gspca_dev *) urb->context;
        int st;

        PDEBUG(D_PACK, "bulk irq");
        if (!gspca_dev->streaming)
                return;
        switch (urb->status) {
        case 0:
                break;
        case -ESHUTDOWN:
                return;         /* disconnection */
        default:
#ifdef CONFIG_PM
                if (gspca_dev->frozen)
                        return;
#endif
                PERR("urb status: %d", urb->status);
                urb->status = 0;
                goto resubmit;
        }

        PDEBUG(D_PACK, "packet l:%d", urb->actual_length);
        gspca_dev->sd_desc->pkt_scan(gspca_dev,
                                urb->transfer_buffer,
                                urb->actual_length);

resubmit:
        /* resubmit the URB */
        if (gspca_dev->cam.bulk_nurbs != 0) {
                st = usb_submit_urb(urb, GFP_ATOMIC);
                if (st < 0)
                        pr_err("usb_submit_urb() ret %d\n", st);
        }
}

/*
 * add data to the current frame
 *
 * This function is called by the subdrivers at interrupt level.
 *
 * To build a frame, these ones must add
 *      - one FIRST_PACKET
 *      - 0 or many INTER_PACKETs
 *      - one LAST_PACKET
 * DISCARD_PACKET invalidates the whole frame.
 */
void gspca_frame_add(struct gspca_dev *gspca_dev,
                        enum gspca_packet_type packet_type,
                        const u8 *data,
                        int len)
{
        struct gspca_frame *frame;
        int i, j;

        PDEBUG(D_PACK, "add t:%d l:%d", packet_type, len);

        if (packet_type == FIRST_PACKET) {
                i = atomic_read(&gspca_dev->fr_i);

                /* if there are no queued buffer, discard the whole frame */
                if (i == atomic_read(&gspca_dev->fr_q)) {
                        gspca_dev->last_packet_type = DISCARD_PACKET;
                        gspca_dev->sequence++;
                        return;
                }
                j = gspca_dev->fr_queue[i];
                frame = &gspca_dev->frame[j];
                frame->v4l2_buf.timestamp = ktime_to_timeval(ktime_get());
                frame->v4l2_buf.sequence = gspca_dev->sequence++;
                gspca_dev->image = frame->data;
                gspca_dev->image_len = 0;
        } else {
                switch (gspca_dev->last_packet_type) {
                case DISCARD_PACKET:
                        if (packet_type == LAST_PACKET) {
                                gspca_dev->last_packet_type = packet_type;
                                gspca_dev->image = NULL;
                                gspca_dev->image_len = 0;
                        }
                        return;
                case LAST_PACKET:
                        return;
                }
        }

        /* append the packet to the frame buffer */
        if (len > 0) {
                if (gspca_dev->image_len + len > gspca_dev->frsz) {
                        PERR("frame overflow %d > %d",
                                gspca_dev->image_len + len,
                                gspca_dev->frsz);
                        packet_type = DISCARD_PACKET;
                } else {
/* !! image is NULL only when last pkt is LAST or DISCARD
                        if (gspca_dev->image == NULL) {
                                pr_err("gspca_frame_add() image == NULL\n");
                                return;
                        }
 */
                        memcpy(gspca_dev->image + gspca_dev->image_len,
                                data, len);
                        gspca_dev->image_len += len;
                }
        }
        gspca_dev->last_packet_type = packet_type;

        /* if last packet, invalidate packet concatenation until
         * next first packet, wake up the application and advance
         * in the queue */
        if (packet_type == LAST_PACKET) {
                i = atomic_read(&gspca_dev->fr_i);
                j = gspca_dev->fr_queue[i];
                frame = &gspca_dev->frame[j];
                frame->v4l2_buf.bytesused = gspca_dev->image_len;
                frame->v4l2_buf.flags = (frame->v4l2_buf.flags
                                         | V4L2_BUF_FLAG_DONE)
                                        & ~V4L2_BUF_FLAG_QUEUED;
                i = (i + 1) % GSPCA_MAX_FRAMES;
                atomic_set(&gspca_dev->fr_i, i);
                wake_up_interruptible(&gspca_dev->wq);  /* event = new frame */
                PDEBUG(D_FRAM, "frame complete len:%d",
                        frame->v4l2_buf.bytesused);
                gspca_dev->image = NULL;
                gspca_dev->image_len = 0;
        }
}
EXPORT_SYMBOL(gspca_frame_add);

static int frame_alloc(struct gspca_dev *gspca_dev, struct file *file,
                        enum v4l2_memory memory, unsigned int count)
{
        struct gspca_frame *frame;
        unsigned int frsz;
        int i;

        i = gspca_dev->curr_mode;
        frsz = gspca_dev->cam.cam_mode[i].sizeimage;
        PDEBUG(D_STREAM, "frame alloc frsz: %d", frsz);
        frsz = PAGE_ALIGN(frsz);
        if (count >= GSPCA_MAX_FRAMES)
                count = GSPCA_MAX_FRAMES - 1;
        gspca_dev->frbuf = vmalloc_32(frsz * count);
        if (!gspca_dev->frbuf) {
                pr_err("frame alloc failed\n");
                return -ENOMEM;
        }
        gspca_dev->capt_file = file;
        gspca_dev->memory = memory;
        gspca_dev->frsz = frsz;
        gspca_dev->nframes = count;
        for (i = 0; i < count; i++) {
                frame = &gspca_dev->frame[i];
                frame->v4l2_buf.index = i;
                frame->v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
                frame->v4l2_buf.flags = 0;
                frame->v4l2_buf.field = V4L2_FIELD_NONE;
                frame->v4l2_buf.length = frsz;
                frame->v4l2_buf.memory = memory;
                frame->v4l2_buf.sequence = 0;
                frame->data = gspca_dev->frbuf + i * frsz;
                frame->v4l2_buf.m.offset = i * frsz;
        }
        atomic_set(&gspca_dev->fr_q, 0);
        atomic_set(&gspca_dev->fr_i, 0);
        gspca_dev->fr_o = 0;
        return 0;
}

static void frame_free(struct gspca_dev *gspca_dev)
{
        int i;

        PDEBUG(D_STREAM, "frame free");
        if (gspca_dev->frbuf != NULL) {
                vfree(gspca_dev->frbuf);
                gspca_dev->frbuf = NULL;
                for (i = 0; i < gspca_dev->nframes; i++)
                        gspca_dev->frame[i].data = NULL;
        }
        gspca_dev->nframes = 0;
        gspca_dev->frsz = 0;
        gspca_dev->capt_file = NULL;
        gspca_dev->memory = GSPCA_MEMORY_NO;
}

static void destroy_urbs(struct gspca_dev *gspca_dev)
{
        struct urb *urb;
        unsigned int i;

        PDEBUG(D_STREAM, "kill transfer");
        for (i = 0; i < MAX_NURBS; i++) {
                urb = gspca_dev->urb[i];
                if (urb == NULL)
                        break;

                gspca_dev->urb[i] = NULL;
                usb_kill_urb(urb);
                usb_free_coherent(gspca_dev->dev,
                                  urb->transfer_buffer_length,
                                  urb->transfer_buffer,
                                  urb->transfer_dma);
                usb_free_urb(urb);
        }
}

static int gspca_set_alt0(struct gspca_dev *gspca_dev)
{
        int ret;

        if (gspca_dev->alt == 0)
                return 0;
        ret = usb_set_interface(gspca_dev->dev, gspca_dev->iface, 0);
        if (ret < 0)
                pr_err("set alt 0 err %d\n", ret);
        return ret;
}

/* Note: both the queue and the usb locks should be held when calling this */
static void gspca_stream_off(struct gspca_dev *gspca_dev)
{
        gspca_dev->streaming = 0;
        gspca_dev->usb_err = 0;
        if (gspca_dev->sd_desc->stopN)
                gspca_dev->sd_desc->stopN(gspca_dev);
        destroy_urbs(gspca_dev);
        gspca_input_destroy_urb(gspca_dev);
        gspca_set_alt0(gspca_dev);
        gspca_input_create_urb(gspca_dev);
        if (gspca_dev->sd_desc->stop0)
                gspca_dev->sd_desc->stop0(gspca_dev);
        PDEBUG(D_STREAM, "stream off OK");
}

/*
 * look for an input transfer endpoint in an alternate setting
 */
static struct usb_host_endpoint *alt_xfer(struct usb_host_interface *alt,
                                          int xfer)
{
        struct usb_host_endpoint *ep;
        int i, attr;

        for (i = 0; i < alt->desc.bNumEndpoints; i++) {
                ep = &alt->endpoint[i];
                attr = ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
                if (attr == xfer
                    && ep->desc.wMaxPacketSize != 0
                    && usb_endpoint_dir_in(&ep->desc))
                        return ep;
        }
        return NULL;
}

/* compute the minimum bandwidth for the current transfer */
static u32 which_bandwidth(struct gspca_dev *gspca_dev)
{
        u32 bandwidth;
        int i;

        /* get the (max) image size */
        i = gspca_dev->curr_mode;
        bandwidth = gspca_dev->cam.cam_mode[i].sizeimage;

        /* if the image is compressed, estimate its mean size */
        if (!gspca_dev->cam.needs_full_bandwidth &&
            bandwidth < gspca_dev->cam.cam_mode[i].width *
                                gspca_dev->cam.cam_mode[i].height)
                bandwidth = bandwidth * 3 / 8;  /* 0.375 */

        /* estimate the frame rate */
        if (gspca_dev->sd_desc->get_streamparm) {
                struct v4l2_streamparm parm;

                gspca_dev->sd_desc->get_streamparm(gspca_dev, &parm);
                bandwidth *= parm.parm.capture.timeperframe.denominator;
                bandwidth /= parm.parm.capture.timeperframe.numerator;
        } else {

                /* don't hope more than 15 fps with USB 1.1 and
                 * image resolution >= 640x480 */
                if (gspca_dev->width >= 640
                 && gspca_dev->dev->speed == USB_SPEED_FULL)
                        bandwidth *= 15;                /* 15 fps */
                else
                        bandwidth *= 30;                /* 30 fps */
        }

        PDEBUG(D_STREAM, "min bandwidth: %d", bandwidth);
        return bandwidth;
}

/* endpoint table */
#define MAX_ALT 16
struct ep_tb_s {
        u32 alt;
        u32 bandwidth;
};

/*
 * build the table of the endpoints
 * and compute the minimum bandwidth for the image transfer
 */
static int build_isoc_ep_tb(struct gspca_dev *gspca_dev,
                        struct usb_interface *intf,
                        struct ep_tb_s *ep_tb)
{
        struct usb_host_endpoint *ep;
        int i, j, nbalt, psize, found;
        u32 bandwidth, last_bw;

        nbalt = intf->num_altsetting;
        if (nbalt > MAX_ALT)
                nbalt = MAX_ALT;        /* fixme: should warn */

        /* build the endpoint table */
        i = 0;
        last_bw = 0;
        for (;;) {
                ep_tb->bandwidth = 2000 * 2000 * 120;
                found = 0;
                for (j = 0; j < nbalt; j++) {
                        ep = alt_xfer(&intf->altsetting[j],
                                      USB_ENDPOINT_XFER_ISOC);
                        if (ep == NULL)
                                continue;
                        if (ep->desc.bInterval == 0) {
                                pr_err("alt %d iso endp with 0 interval\n", j);
                                continue;
                        }
                        psize = le16_to_cpu(ep->desc.wMaxPacketSize);
                        psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
                        bandwidth = psize * 1000;
                        if (gspca_dev->dev->speed == USB_SPEED_HIGH
                         || gspca_dev->dev->speed == USB_SPEED_SUPER)
                                bandwidth *= 8;
                        bandwidth /= 1 << (ep->desc.bInterval - 1);
                        if (bandwidth <= last_bw)
                                continue;
                        if (bandwidth < ep_tb->bandwidth) {
                                ep_tb->bandwidth = bandwidth;
                                ep_tb->alt = j;
                                found = 1;
                        }
                }
                if (!found)
                        break;
                PDEBUG(D_STREAM, "alt %d bandwidth %d",
                                ep_tb->alt, ep_tb->bandwidth);
                last_bw = ep_tb->bandwidth;
                i++;
                ep_tb++;
        }

        /*
         * If the camera:
         * has a usb audio class interface (a built in usb mic); and
         * is a usb 1 full speed device; and
         * uses the max full speed iso bandwidth; and
         * and has more than 1 alt setting
         * then skip the highest alt setting to spare bandwidth for the mic
         */
        if (gspca_dev->audio &&
                        gspca_dev->dev->speed == USB_SPEED_FULL &&
                        last_bw >= 1000000 &&
                        i > 1) {
                PDEBUG(D_STREAM, "dev has usb audio, skipping highest alt");
                i--;
                ep_tb--;
        }

        /* get the requested bandwidth and start at the highest atlsetting */
        bandwidth = which_bandwidth(gspca_dev);
        ep_tb--;
        while (i > 1) {
                ep_tb--;
                if (ep_tb->bandwidth < bandwidth)
                        break;
                i--;
        }
        return i;
}

/*
 * create the URBs for image transfer
 */
static int create_urbs(struct gspca_dev *gspca_dev,
                        struct usb_host_endpoint *ep)
{
        struct urb *urb;
        int n, nurbs, i, psize, npkt, bsize;

        /* calculate the packet size and the number of packets */
        psize = le16_to_cpu(ep->desc.wMaxPacketSize);

        if (!gspca_dev->cam.bulk) {             /* isoc */

                /* See paragraph 5.9 / table 5-11 of the usb 2.0 spec. */
                if (gspca_dev->pkt_size == 0)
                        psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
                else
                        psize = gspca_dev->pkt_size;
                npkt = gspca_dev->cam.npkt;
                if (npkt == 0)
                        npkt = 32;              /* default value */
                bsize = psize * npkt;
                PDEBUG(D_STREAM,
                        "isoc %d pkts size %d = bsize:%d",
                        npkt, psize, bsize);
                nurbs = DEF_NURBS;
        } else {                                /* bulk */
                npkt = 0;
                bsize = gspca_dev->cam.bulk_size;
                if (bsize == 0)
                        bsize = psize;
                PDEBUG(D_STREAM, "bulk bsize:%d", bsize);
                if (gspca_dev->cam.bulk_nurbs != 0)
                        nurbs = gspca_dev->cam.bulk_nurbs;
                else
                        nurbs = 1;
        }

        for (n = 0; n < nurbs; n++) {
                urb = usb_alloc_urb(npkt, GFP_KERNEL);
                if (!urb) {
                        pr_err("usb_alloc_urb failed\n");
                        return -ENOMEM;
                }
                gspca_dev->urb[n] = urb;
                urb->transfer_buffer = usb_alloc_coherent(gspca_dev->dev,
                                                bsize,
                                                GFP_KERNEL,
                                                &urb->transfer_dma);

                if (urb->transfer_buffer == NULL) {
                        pr_err("usb_alloc_coherent failed\n");
                        return -ENOMEM;
                }
                urb->dev = gspca_dev->dev;
                urb->context = gspca_dev;
                urb->transfer_buffer_length = bsize;
                if (npkt != 0) {                /* ISOC */
                        urb->pipe = usb_rcvisocpipe(gspca_dev->dev,
                                                    ep->desc.bEndpointAddress);
                        urb->transfer_flags = URB_ISO_ASAP
                                        | URB_NO_TRANSFER_DMA_MAP;
                        urb->interval = 1 << (ep->desc.bInterval - 1);
                        urb->complete = isoc_irq;
                        urb->number_of_packets = npkt;
                        for (i = 0; i < npkt; i++) {
                                urb->iso_frame_desc[i].length = psize;
                                urb->iso_frame_desc[i].offset = psize * i;
                        }
                } else {                /* bulk */
                        urb->pipe = usb_rcvbulkpipe(gspca_dev->dev,
                                                ep->desc.bEndpointAddress);
                        urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
                        urb->complete = bulk_irq;
                }
        }
        return 0;
}

/*
 * start the USB transfer
 */
static int gspca_init_transfer(struct gspca_dev *gspca_dev)
{
        struct usb_interface *intf;
        struct usb_host_endpoint *ep;
        struct urb *urb;
        struct ep_tb_s ep_tb[MAX_ALT];
        int n, ret, xfer, alt, alt_idx;

        /* reset the streaming variables */
        gspca_dev->image = NULL;
        gspca_dev->image_len = 0;
        gspca_dev->last_packet_type = DISCARD_PACKET;
        gspca_dev->sequence = 0;

        gspca_dev->usb_err = 0;

        /* do the specific subdriver stuff before endpoint selection */
        intf = usb_ifnum_to_if(gspca_dev->dev, gspca_dev->iface);
        gspca_dev->alt = gspca_dev->cam.bulk ? intf->num_altsetting : 0;
        if (gspca_dev->sd_desc->isoc_init) {
                ret = gspca_dev->sd_desc->isoc_init(gspca_dev);
                if (ret < 0)
                        return ret;
        }
        xfer = gspca_dev->cam.bulk ? USB_ENDPOINT_XFER_BULK
                                   : USB_ENDPOINT_XFER_ISOC;

        /* if bulk or the subdriver forced an altsetting, get the endpoint */
        if (gspca_dev->alt != 0) {
                gspca_dev->alt--;       /* (previous version compatibility) */
                ep = alt_xfer(&intf->altsetting[gspca_dev->alt], xfer);
                if (ep == NULL) {
                        pr_err("bad altsetting %d\n", gspca_dev->alt);
                        return -EIO;
                }
                ep_tb[0].alt = gspca_dev->alt;
                alt_idx = 1;
        } else {

        /* else, compute the minimum bandwidth
         * and build the endpoint table */
                alt_idx = build_isoc_ep_tb(gspca_dev, intf, ep_tb);
                if (alt_idx <= 0) {
                        pr_err("no transfer endpoint found\n");
                        return -EIO;
                }
        }

        /* set the highest alternate setting and
         * loop until urb submit succeeds */
        gspca_input_destroy_urb(gspca_dev);

        gspca_dev->alt = ep_tb[--alt_idx].alt;
        alt = -1;
        for (;;) {
                if (alt != gspca_dev->alt) {
                        alt = gspca_dev->alt;
                        if (intf->num_altsetting > 1) {
                                ret = usb_set_interface(gspca_dev->dev,
                                                        gspca_dev->iface,
                                                        alt);
                                if (ret < 0) {
                                        if (ret == -ENOSPC)
                                                goto retry; /*fixme: ugly*/
                                        pr_err("set alt %d err %d\n", alt, ret);
                                        goto out;
                                }
                        }
                }
                if (!gspca_dev->cam.no_urb_create) {
                        PDEBUG(D_STREAM, "init transfer alt %d", alt);
                        ret = create_urbs(gspca_dev,
                                alt_xfer(&intf->altsetting[alt], xfer));
                        if (ret < 0) {
                                destroy_urbs(gspca_dev);
                                goto out;
                        }
                }

                /* clear the bulk endpoint */
                if (gspca_dev->cam.bulk)
                        usb_clear_halt(gspca_dev->dev,
                                        gspca_dev->urb[0]->pipe);

                /* start the cam */
                ret = gspca_dev->sd_desc->start(gspca_dev);
                if (ret < 0) {
                        destroy_urbs(gspca_dev);
                        goto out;
                }
                gspca_dev->streaming = 1;
                v4l2_ctrl_handler_setup(gspca_dev->vdev.ctrl_handler);

                /* some bulk transfers are started by the subdriver */
                if (gspca_dev->cam.bulk && gspca_dev->cam.bulk_nurbs == 0)
                        break;

                /* submit the URBs */
                for (n = 0; n < MAX_NURBS; n++) {
                        urb = gspca_dev->urb[n];
                        if (urb == NULL)
                                break;
                        ret = usb_submit_urb(urb, GFP_KERNEL);
                        if (ret < 0)
                                break;
                }
                if (ret >= 0)
                        break;                  /* transfer is started */

                /* something when wrong
                 * stop the webcam and free the transfer resources */
                gspca_stream_off(gspca_dev);
                if (ret != -ENOSPC) {
                        pr_err("usb_submit_urb alt %d err %d\n",
                               gspca_dev->alt, ret);
                        goto out;
                }

                /* the bandwidth is not wide enough
                 * negotiate or try a lower alternate setting */
retry:
                PERR("alt %d - bandwidth not wide enough, trying again", alt);
                msleep(20);     /* wait for kill complete */
                if (gspca_dev->sd_desc->isoc_nego) {
                        ret = gspca_dev->sd_desc->isoc_nego(gspca_dev);
                        if (ret < 0)
                                goto out;
                } else {
                        if (alt_idx <= 0) {
                                pr_err("no transfer endpoint found\n");
                                ret = -EIO;
                                goto out;
                        }
                        gspca_dev->alt = ep_tb[--alt_idx].alt;
                }
        }
out:
        gspca_input_create_urb(gspca_dev);
        return ret;
}

static void gspca_set_default_mode(struct gspca_dev *gspca_dev)
{
        int i;

        i = gspca_dev->cam.nmodes - 1;  /* take the highest mode */
        gspca_dev->curr_mode = i;
        gspca_dev->width = gspca_dev->cam.cam_mode[i].width;
        gspca_dev->height = gspca_dev->cam.cam_mode[i].height;
        gspca_dev->pixfmt = gspca_dev->cam.cam_mode[i].pixelformat;

        /* does nothing if ctrl_handler == NULL */
        v4l2_ctrl_handler_setup(gspca_dev->vdev.ctrl_handler);
}

static int wxh_to_mode(struct gspca_dev *gspca_dev,
                        int width, int height)
{
        int i;

        for (i = gspca_dev->cam.nmodes; --i > 0; ) {
                if (width >= gspca_dev->cam.cam_mode[i].width
                    && height >= gspca_dev->cam.cam_mode[i].height)

                        break;
        }
        return i;
}

/*
 * search a mode with the right pixel format
 */
static int gspca_get_mode(struct gspca_dev *gspca_dev,
                        int mode,
                        int pixfmt)
{
        int modeU, modeD;

        modeU = modeD = mode;
        while ((modeU < gspca_dev->cam.nmodes) || modeD >= 0) {
                if (--modeD >= 0) {
                        if (gspca_dev->cam.cam_mode[modeD].pixelformat
                                                                == pixfmt)
                                return modeD;
                }
                if (++modeU < gspca_dev->cam.nmodes) {
                        if (gspca_dev->cam.cam_mode[modeU].pixelformat
                                                                == pixfmt)
                                return modeU;
                }
        }
        return -EINVAL;
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int vidioc_g_chip_info(struct file *file, void *priv,
                                struct v4l2_dbg_chip_info *chip)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);

        gspca_dev->usb_err = 0;
        if (gspca_dev->sd_desc->get_chip_info)
                return gspca_dev->sd_desc->get_chip_info(gspca_dev, chip);
        return chip->match.addr ? -EINVAL : 0;
}

static int vidioc_g_register(struct file *file, void *priv,
                struct v4l2_dbg_register *reg)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);

        gspca_dev->usb_err = 0;
        return gspca_dev->sd_desc->get_register(gspca_dev, reg);
}

static int vidioc_s_register(struct file *file, void *priv,
                const struct v4l2_dbg_register *reg)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);

        gspca_dev->usb_err = 0;
        return gspca_dev->sd_desc->set_register(gspca_dev, reg);
}
#endif

static int vidioc_enum_fmt_vid_cap(struct file *file, void  *priv,
                                struct v4l2_fmtdesc *fmtdesc)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        int i, j, index;
        __u32 fmt_tb[8];

        /* give an index to each format */
        index = 0;
        j = 0;
        for (i = gspca_dev->cam.nmodes; --i >= 0; ) {
                fmt_tb[index] = gspca_dev->cam.cam_mode[i].pixelformat;
                j = 0;
                for (;;) {
                        if (fmt_tb[j] == fmt_tb[index])
                                break;
                        j++;
                }
                if (j == index) {
                        if (fmtdesc->index == index)
                                break;          /* new format */
                        index++;
                        if (index >= ARRAY_SIZE(fmt_tb))
                                return -EINVAL;
                }
        }
        if (i < 0)
                return -EINVAL;         /* no more format */

        fmtdesc->pixelformat = fmt_tb[index];
        if (gspca_dev->cam.cam_mode[i].sizeimage <
                        gspca_dev->cam.cam_mode[i].width *
                                gspca_dev->cam.cam_mode[i].height)
                fmtdesc->flags = V4L2_FMT_FLAG_COMPRESSED;
        fmtdesc->description[0] = fmtdesc->pixelformat & 0xff;
        fmtdesc->description[1] = (fmtdesc->pixelformat >> 8) & 0xff;
        fmtdesc->description[2] = (fmtdesc->pixelformat >> 16) & 0xff;
        fmtdesc->description[3] = fmtdesc->pixelformat >> 24;
        fmtdesc->description[4] = '\0';
        return 0;
}

static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
                            struct v4l2_format *fmt)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        int mode;

        mode = gspca_dev->curr_mode;
        fmt->fmt.pix = gspca_dev->cam.cam_mode[mode];
        /* some drivers use priv internally, zero it before giving it to
           userspace */
        fmt->fmt.pix.priv = 0;
        return 0;
}

static int try_fmt_vid_cap(struct gspca_dev *gspca_dev,
                        struct v4l2_format *fmt)
{
        int w, h, mode, mode2;

        w = fmt->fmt.pix.width;
        h = fmt->fmt.pix.height;

        PDEBUG_MODE(gspca_dev, D_CONF, "try fmt cap",
                    fmt->fmt.pix.pixelformat, w, h);

        /* search the closest mode for width and height */
        mode = wxh_to_mode(gspca_dev, w, h);

        /* OK if right palette */
        if (gspca_dev->cam.cam_mode[mode].pixelformat
                                                != fmt->fmt.pix.pixelformat) {

                /* else, search the closest mode with the same pixel format */
                mode2 = gspca_get_mode(gspca_dev, mode,
                                        fmt->fmt.pix.pixelformat);
                if (mode2 >= 0)
                        mode = mode2;
        }
        fmt->fmt.pix = gspca_dev->cam.cam_mode[mode];
        /* some drivers use priv internally, zero it before giving it to
           userspace */
        fmt->fmt.pix.priv = 0;
        return mode;                    /* used when s_fmt */
}

static int vidioc_try_fmt_vid_cap(struct file *file,
                              void *priv,
                              struct v4l2_format *fmt)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        int ret;

        ret = try_fmt_vid_cap(gspca_dev, fmt);
        if (ret < 0)
                return ret;
        return 0;
}

static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
                            struct v4l2_format *fmt)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        int ret;

        if (mutex_lock_interruptible(&gspca_dev->queue_lock))
                return -ERESTARTSYS;

        ret = try_fmt_vid_cap(gspca_dev, fmt);
        if (ret < 0)
                goto out;

        if (gspca_dev->nframes != 0
            && fmt->fmt.pix.sizeimage > gspca_dev->frsz) {
                ret = -EINVAL;
                goto out;
        }

        if (ret == gspca_dev->curr_mode) {
                ret = 0;
                goto out;                       /* same mode */
        }

        if (gspca_dev->streaming) {
                ret = -EBUSY;
                goto out;
        }
        gspca_dev->width = fmt->fmt.pix.width;
        gspca_dev->height = fmt->fmt.pix.height;
        gspca_dev->pixfmt = fmt->fmt.pix.pixelformat;
        gspca_dev->curr_mode = ret;

        ret = 0;
out:
        mutex_unlock(&gspca_dev->queue_lock);
        return ret;
}

static int vidioc_enum_framesizes(struct file *file, void *priv,
                                  struct v4l2_frmsizeenum *fsize)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        int i;
        __u32 index = 0;

        for (i = 0; i < gspca_dev->cam.nmodes; i++) {
                if (fsize->pixel_format !=
                                gspca_dev->cam.cam_mode[i].pixelformat)
                        continue;

                if (fsize->index == index) {
                        fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
                        fsize->discrete.width =
                                gspca_dev->cam.cam_mode[i].width;
                        fsize->discrete.height =
                                gspca_dev->cam.cam_mode[i].height;
                        return 0;
                }
                index++;
        }

        return -EINVAL;
}

static int vidioc_enum_frameintervals(struct file *filp, void *priv,
                                      struct v4l2_frmivalenum *fival)
{
        struct gspca_dev *gspca_dev = video_drvdata(filp);
        int mode = wxh_to_mode(gspca_dev, fival->width, fival->height);
        __u32 i;

        if (gspca_dev->cam.mode_framerates == NULL ||
                        gspca_dev->cam.mode_framerates[mode].nrates == 0)
                return -EINVAL;

        if (fival->pixel_format !=
                        gspca_dev->cam.cam_mode[mode].pixelformat)
                return -EINVAL;

        for (i = 0; i < gspca_dev->cam.mode_framerates[mode].nrates; i++) {
                if (fival->index == i) {
                        fival->type = V4L2_FRMSIZE_TYPE_DISCRETE;
                        fival->discrete.numerator = 1;
                        fival->discrete.denominator =
                                gspca_dev->cam.mode_framerates[mode].rates[i];
                        return 0;
                }
        }

        return -EINVAL;
}

static void gspca_release(struct v4l2_device *v4l2_device)
{
        struct gspca_dev *gspca_dev =
                container_of(v4l2_device, struct gspca_dev, v4l2_dev);

        v4l2_ctrl_handler_free(gspca_dev->vdev.ctrl_handler);
        v4l2_device_unregister(&gspca_dev->v4l2_dev);
        kfree(gspca_dev->usb_buf);
        kfree(gspca_dev);
}

static int dev_open(struct file *file)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);

        PDEBUG(D_STREAM, "[%s] open", current->comm);

        /* protect the subdriver against rmmod */
        if (!try_module_get(gspca_dev->module))
                return -ENODEV;

        return v4l2_fh_open(file);
}

static int dev_close(struct file *file)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);

        PDEBUG(D_STREAM, "[%s] close", current->comm);

        /* Needed for gspca_stream_off, always lock before queue_lock! */
        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
                return -ERESTARTSYS;

        if (mutex_lock_interruptible(&gspca_dev->queue_lock)) {
                mutex_unlock(&gspca_dev->usb_lock);
                return -ERESTARTSYS;
        }

        /* if the file did the capture, free the streaming resources */
        if (gspca_dev->capt_file == file) {
                if (gspca_dev->streaming)
                        gspca_stream_off(gspca_dev);
                frame_free(gspca_dev);
        }
        module_put(gspca_dev->module);
        mutex_unlock(&gspca_dev->queue_lock);
        mutex_unlock(&gspca_dev->usb_lock);

        PDEBUG(D_STREAM, "close done");

        return v4l2_fh_release(file);
}

static int vidioc_querycap(struct file *file, void  *priv,
                           struct v4l2_capability *cap)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);

        strlcpy((char *) cap->driver, gspca_dev->sd_desc->name,
                        sizeof cap->driver);
        if (gspca_dev->dev->product != NULL) {
                strlcpy((char *) cap->card, gspca_dev->dev->product,
                        sizeof cap->card);
        } else {
                snprintf((char *) cap->card, sizeof cap->card,
                        "USB Camera (%04x:%04x)",
                        le16_to_cpu(gspca_dev->dev->descriptor.idVendor),
                        le16_to_cpu(gspca_dev->dev->descriptor.idProduct));
        }
        usb_make_path(gspca_dev->dev, (char *) cap->bus_info,
                        sizeof(cap->bus_info));
        cap->device_caps = V4L2_CAP_VIDEO_CAPTURE
                          | V4L2_CAP_STREAMING
                          | V4L2_CAP_READWRITE;
        cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
        return 0;
}

static int vidioc_enum_input(struct file *file, void *priv,
                                struct v4l2_input *input)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);

        if (input->index != 0)
                return -EINVAL;
        input->type = V4L2_INPUT_TYPE_CAMERA;
        input->status = gspca_dev->cam.input_flags;
        strlcpy(input->name, gspca_dev->sd_desc->name,
                sizeof input->name);
        return 0;
}

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

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

static int vidioc_reqbufs(struct file *file, void *priv,
                          struct v4l2_requestbuffers *rb)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        int i, ret = 0, streaming;

        i = rb->memory;                 /* (avoid compilation warning) */
        switch (i) {
        case GSPCA_MEMORY_READ:                 /* (internal call) */
        case V4L2_MEMORY_MMAP:
        case V4L2_MEMORY_USERPTR:
                break;
        default:
                return -EINVAL;
        }
        if (mutex_lock_interruptible(&gspca_dev->queue_lock))
                return -ERESTARTSYS;

        if (gspca_dev->memory != GSPCA_MEMORY_NO
            && gspca_dev->memory != GSPCA_MEMORY_READ
            && gspca_dev->memory != rb->memory) {
                ret = -EBUSY;
                goto out;
        }

        /* only one file may do the capture */
        if (gspca_dev->capt_file != NULL
            && gspca_dev->capt_file != file) {
                ret = -EBUSY;
                goto out;
        }

        /* if allocated, the buffers must not be mapped */
        for (i = 0; i < gspca_dev->nframes; i++) {
                if (gspca_dev->frame[i].vma_use_count) {
                        ret = -EBUSY;
                        goto out;
                }
        }

        /* stop streaming */
        streaming = gspca_dev->streaming;
        if (streaming) {
                gspca_stream_off(gspca_dev);

                /* Don't restart the stream when switching from read
                 * to mmap mode */
                if (gspca_dev->memory == GSPCA_MEMORY_READ)
                        streaming = 0;
        }

        /* free the previous allocated buffers, if any */
        if (gspca_dev->nframes != 0)
                frame_free(gspca_dev);
        if (rb->count == 0)                     /* unrequest */
                goto out;
        ret = frame_alloc(gspca_dev, file, rb->memory, rb->count);
        if (ret == 0) {
                rb->count = gspca_dev->nframes;
                if (streaming)
                        ret = gspca_init_transfer(gspca_dev);
        }
out:
        mutex_unlock(&gspca_dev->queue_lock);
        PDEBUG(D_STREAM, "reqbufs st:%d c:%d", ret, rb->count);
        return ret;
}

static int vidioc_querybuf(struct file *file, void *priv,
                           struct v4l2_buffer *v4l2_buf)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        struct gspca_frame *frame;

        if (v4l2_buf->index >= gspca_dev->nframes)
                return -EINVAL;

        frame = &gspca_dev->frame[v4l2_buf->index];
        memcpy(v4l2_buf, &frame->v4l2_buf, sizeof *v4l2_buf);
        return 0;
}

static int vidioc_streamon(struct file *file, void *priv,
                           enum v4l2_buf_type buf_type)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        int ret;

        if (buf_type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                return -EINVAL;
        if (mutex_lock_interruptible(&gspca_dev->queue_lock))
                return -ERESTARTSYS;

        /* check the capture file */
        if (gspca_dev->capt_file != file) {
                ret = -EBUSY;
                goto out;
        }

        if (gspca_dev->nframes == 0
            || !(gspca_dev->frame[0].v4l2_buf.flags & V4L2_BUF_FLAG_QUEUED)) {
                ret = -EINVAL;
                goto out;
        }
        if (!gspca_dev->streaming) {
                ret = gspca_init_transfer(gspca_dev);
                if (ret < 0)
                        goto out;
        }
        PDEBUG_MODE(gspca_dev, D_STREAM, "stream on OK", gspca_dev->pixfmt,
                    gspca_dev->width, gspca_dev->height);
        ret = 0;
out:
        mutex_unlock(&gspca_dev->queue_lock);
        return ret;
}

static int vidioc_streamoff(struct file *file, void *priv,
                                enum v4l2_buf_type buf_type)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        int i, ret;

        if (buf_type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                return -EINVAL;

        if (mutex_lock_interruptible(&gspca_dev->queue_lock))
                return -ERESTARTSYS;

        if (!gspca_dev->streaming) {
                ret = 0;
                goto out;
        }

        /* check the capture file */
        if (gspca_dev->capt_file != file) {
                ret = -EBUSY;
                goto out;
        }

        /* stop streaming */
        gspca_stream_off(gspca_dev);
        /* In case another thread is waiting in dqbuf */
        wake_up_interruptible(&gspca_dev->wq);

        /* empty the transfer queues */
        for (i = 0; i < gspca_dev->nframes; i++)
                gspca_dev->frame[i].v4l2_buf.flags &= ~BUF_ALL_FLAGS;
        atomic_set(&gspca_dev->fr_q, 0);
        atomic_set(&gspca_dev->fr_i, 0);
        gspca_dev->fr_o = 0;
        ret = 0;
out:
        mutex_unlock(&gspca_dev->queue_lock);
        return ret;
}

static int vidioc_g_jpegcomp(struct file *file, void *priv,
                        struct v4l2_jpegcompression *jpegcomp)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);

        gspca_dev->usb_err = 0;
        return gspca_dev->sd_desc->get_jcomp(gspca_dev, jpegcomp);
}

static int vidioc_s_jpegcomp(struct file *file, void *priv,
                        const struct v4l2_jpegcompression *jpegcomp)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);

        gspca_dev->usb_err = 0;
        return gspca_dev->sd_desc->set_jcomp(gspca_dev, jpegcomp);
}

static int vidioc_g_parm(struct file *filp, void *priv,
                        struct v4l2_streamparm *parm)
{
        struct gspca_dev *gspca_dev = video_drvdata(filp);

        parm->parm.capture.readbuffers = gspca_dev->nbufread;

        if (gspca_dev->sd_desc->get_streamparm) {
                gspca_dev->usb_err = 0;
                gspca_dev->sd_desc->get_streamparm(gspca_dev, parm);
                return gspca_dev->usb_err;
        }
        return 0;
}

static int vidioc_s_parm(struct file *filp, void *priv,
                        struct v4l2_streamparm *parm)
{
        struct gspca_dev *gspca_dev = video_drvdata(filp);
        int n;

        n = parm->parm.capture.readbuffers;
        if (n == 0 || n >= GSPCA_MAX_FRAMES)
                parm->parm.capture.readbuffers = gspca_dev->nbufread;
        else
                gspca_dev->nbufread = n;

        if (gspca_dev->sd_desc->set_streamparm) {
                gspca_dev->usb_err = 0;
                gspca_dev->sd_desc->set_streamparm(gspca_dev, parm);
                return gspca_dev->usb_err;
        }

        return 0;
}

static int dev_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        struct gspca_frame *frame;
        struct page *page;
        unsigned long addr, start, size;
        int i, ret;

        start = vma->vm_start;
        size = vma->vm_end - vma->vm_start;
        PDEBUG(D_STREAM, "mmap start:%08x size:%d", (int) start, (int) size);

        if (mutex_lock_interruptible(&gspca_dev->queue_lock))
                return -ERESTARTSYS;
        if (gspca_dev->capt_file != file) {
                ret = -EINVAL;
                goto out;
        }

        frame = NULL;
        for (i = 0; i < gspca_dev->nframes; ++i) {
                if (gspca_dev->frame[i].v4l2_buf.memory != V4L2_MEMORY_MMAP) {
                        PDEBUG(D_STREAM, "mmap bad memory type");
                        break;
                }
                if ((gspca_dev->frame[i].v4l2_buf.m.offset >> PAGE_SHIFT)
                                                == vma->vm_pgoff) {
                        frame = &gspca_dev->frame[i];
                        break;
                }
        }
        if (frame == NULL) {
                PDEBUG(D_STREAM, "mmap no frame buffer found");
                ret = -EINVAL;
                goto out;
        }
        if (size != frame->v4l2_buf.length) {
                PDEBUG(D_STREAM, "mmap bad size");
                ret = -EINVAL;
                goto out;
        }

        /*
         * - VM_IO marks the area as being a mmaped region for I/O to a
         *   device. It also prevents the region from being core dumped.
         */
        vma->vm_flags |= VM_IO;

        addr = (unsigned long) frame->data;
        while (size > 0) {
                page = vmalloc_to_page((void *) addr);
                ret = vm_insert_page(vma, start, page);
                if (ret < 0)
                        goto out;
                start += PAGE_SIZE;
                addr += PAGE_SIZE;
                size -= PAGE_SIZE;
        }

        vma->vm_ops = &gspca_vm_ops;
        vma->vm_private_data = frame;
        gspca_vm_open(vma);
        ret = 0;
out:
        mutex_unlock(&gspca_dev->queue_lock);
        return ret;
}

static int frame_ready_nolock(struct gspca_dev *gspca_dev, struct file *file,
                                enum v4l2_memory memory)
{
        if (!gspca_dev->present)
                return -ENODEV;
        if (gspca_dev->capt_file != file || gspca_dev->memory != memory ||
                        !gspca_dev->streaming)
                return -EINVAL;

        /* check if a frame is ready */
        return gspca_dev->fr_o != atomic_read(&gspca_dev->fr_i);
}

static int frame_ready(struct gspca_dev *gspca_dev, struct file *file,
                        enum v4l2_memory memory)
{
        int ret;

        if (mutex_lock_interruptible(&gspca_dev->queue_lock))
                return -ERESTARTSYS;
        ret = frame_ready_nolock(gspca_dev, file, memory);
        mutex_unlock(&gspca_dev->queue_lock);
        return ret;
}

/*
 * dequeue a video buffer
 *
 * If nonblock_ing is false, block until a buffer is available.
 */
static int vidioc_dqbuf(struct file *file, void *priv,
                        struct v4l2_buffer *v4l2_buf)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        struct gspca_frame *frame;
        int i, j, ret;

        PDEBUG(D_FRAM, "dqbuf");

        if (mutex_lock_interruptible(&gspca_dev->queue_lock))
                return -ERESTARTSYS;

        for (;;) {
                ret = frame_ready_nolock(gspca_dev, file, v4l2_buf->memory);
                if (ret < 0)
                        goto out;
                if (ret > 0)
                        break;

                mutex_unlock(&gspca_dev->queue_lock);

                if (file->f_flags & O_NONBLOCK)
                        return -EAGAIN;

                /* wait till a frame is ready */
                ret = wait_event_interruptible_timeout(gspca_dev->wq,
                        frame_ready(gspca_dev, file, v4l2_buf->memory),
                        msecs_to_jiffies(3000));
                if (ret < 0)
                        return ret;
                if (ret == 0)
                        return -EIO;

                if (mutex_lock_interruptible(&gspca_dev->queue_lock))
                        return -ERESTARTSYS;
        }

        i = gspca_dev->fr_o;
        j = gspca_dev->fr_queue[i];
        frame = &gspca_dev->frame[j];

        gspca_dev->fr_o = (i + 1) % GSPCA_MAX_FRAMES;

        frame->v4l2_buf.flags &= ~V4L2_BUF_FLAG_DONE;
        memcpy(v4l2_buf, &frame->v4l2_buf, sizeof *v4l2_buf);
        PDEBUG(D_FRAM, "dqbuf %d", j);
        ret = 0;

        if (gspca_dev->memory == V4L2_MEMORY_USERPTR) {
                if (copy_to_user((__u8 __user *) frame->v4l2_buf.m.userptr,
                                 frame->data,
                                 frame->v4l2_buf.bytesused)) {
                        PERR("dqbuf cp to user failed");
                        ret = -EFAULT;
                }
        }
out:
        mutex_unlock(&gspca_dev->queue_lock);

        if (ret == 0 && gspca_dev->sd_desc->dq_callback) {
                mutex_lock(&gspca_dev->usb_lock);
                gspca_dev->usb_err = 0;
                if (gspca_dev->present)
                        gspca_dev->sd_desc->dq_callback(gspca_dev);
                mutex_unlock(&gspca_dev->usb_lock);
        }

        return ret;
}

/*
 * queue a video buffer
 *
 * Attempting to queue a buffer that has already been
 * queued will return -EINVAL.
 */
static int vidioc_qbuf(struct file *file, void *priv,
                        struct v4l2_buffer *v4l2_buf)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        struct gspca_frame *frame;
        int i, index, ret;

        PDEBUG(D_FRAM, "qbuf %d", v4l2_buf->index);

        if (mutex_lock_interruptible(&gspca_dev->queue_lock))
                return -ERESTARTSYS;

        index = v4l2_buf->index;
        if ((unsigned) index >= gspca_dev->nframes) {
                PDEBUG(D_FRAM,
                        "qbuf idx %d >= %d", index, gspca_dev->nframes);
                ret = -EINVAL;
                goto out;
        }
        if (v4l2_buf->memory != gspca_dev->memory) {
                PDEBUG(D_FRAM, "qbuf bad memory type");
                ret = -EINVAL;
                goto out;
        }

        frame = &gspca_dev->frame[index];
        if (frame->v4l2_buf.flags & BUF_ALL_FLAGS) {
                PDEBUG(D_FRAM, "qbuf bad state");
                ret = -EINVAL;
                goto out;
        }

        frame->v4l2_buf.flags |= V4L2_BUF_FLAG_QUEUED;

        if (frame->v4l2_buf.memory == V4L2_MEMORY_USERPTR) {
                frame->v4l2_buf.m.userptr = v4l2_buf->m.userptr;
                frame->v4l2_buf.length = v4l2_buf->length;
        }

        /* put the buffer in the 'queued' queue */
        i = atomic_read(&gspca_dev->fr_q);
        gspca_dev->fr_queue[i] = index;
        atomic_set(&gspca_dev->fr_q, (i + 1) % GSPCA_MAX_FRAMES);

        v4l2_buf->flags |= V4L2_BUF_FLAG_QUEUED;
        v4l2_buf->flags &= ~V4L2_BUF_FLAG_DONE;
        ret = 0;
out:
        mutex_unlock(&gspca_dev->queue_lock);
        return ret;
}

/*
 * allocate the resources for read()
 */
static int read_alloc(struct gspca_dev *gspca_dev,
                        struct file *file)
{
        struct v4l2_buffer v4l2_buf;
        int i, ret;

        PDEBUG(D_STREAM, "read alloc");

        if (mutex_lock_interruptible(&gspca_dev->usb_lock))
                return -ERESTARTSYS;

        if (gspca_dev->nframes == 0) {
                struct v4l2_requestbuffers rb;

                memset(&rb, 0, sizeof rb);
                rb.count = gspca_dev->nbufread;
                rb.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
                rb.memory = GSPCA_MEMORY_READ;
                ret = vidioc_reqbufs(file, gspca_dev, &rb);
                if (ret != 0) {
                        PDEBUG(D_STREAM, "read reqbuf err %d", ret);
                        goto out;
                }
                memset(&v4l2_buf, 0, sizeof v4l2_buf);
                v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
                v4l2_buf.memory = GSPCA_MEMORY_READ;
                for (i = 0; i < gspca_dev->nbufread; i++) {
                        v4l2_buf.index = i;
                        ret = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
                        if (ret != 0) {
                                PDEBUG(D_STREAM, "read qbuf err: %d", ret);
                                goto out;
                        }
                }
        }

        /* start streaming */
        ret = vidioc_streamon(file, gspca_dev, V4L2_BUF_TYPE_VIDEO_CAPTURE);
        if (ret != 0)
                PDEBUG(D_STREAM, "read streamon err %d", ret);
out:
        mutex_unlock(&gspca_dev->usb_lock);
        return ret;
}

static unsigned int dev_poll(struct file *file, poll_table *wait)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        unsigned long req_events = poll_requested_events(wait);
        int ret = 0;

        PDEBUG(D_FRAM, "poll");

        if (req_events & POLLPRI)
                ret |= v4l2_ctrl_poll(file, wait);

        if (req_events & (POLLIN | POLLRDNORM)) {
                /* if reqbufs is not done, the user would use read() */
                if (gspca_dev->memory == GSPCA_MEMORY_NO) {
                        if (read_alloc(gspca_dev, file) != 0) {
                                ret |= POLLERR;
                                goto out;
                        }
                }

                poll_wait(file, &gspca_dev->wq, wait);

                /* check if an image has been received */
                if (mutex_lock_interruptible(&gspca_dev->queue_lock) != 0) {
                        ret |= POLLERR;
                        goto out;
                }
                if (gspca_dev->fr_o != atomic_read(&gspca_dev->fr_i))
                        ret |= POLLIN | POLLRDNORM;
                mutex_unlock(&gspca_dev->queue_lock);
        }

out:
        if (!gspca_dev->present)
                ret |= POLLHUP;

        return ret;
}

static ssize_t dev_read(struct file *file, char __user *data,
                    size_t count, loff_t *ppos)
{
        struct gspca_dev *gspca_dev = video_drvdata(file);
        struct gspca_frame *frame;
        struct v4l2_buffer v4l2_buf;
        struct timeval timestamp;
        int n, ret, ret2;

        PDEBUG(D_FRAM, "read (%zd)", count);
        if (gspca_dev->memory == GSPCA_MEMORY_NO) { /* first time ? */
                ret = read_alloc(gspca_dev, file);
                if (ret != 0)
                        return ret;
        }

        /* get a frame */
        timestamp = ktime_to_timeval(ktime_get());
        timestamp.tv_sec--;
        n = 2;
        for (;;) {
                memset(&v4l2_buf, 0, sizeof v4l2_buf);
                v4l2_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
                v4l2_buf.memory = GSPCA_MEMORY_READ;
                ret = vidioc_dqbuf(file, gspca_dev, &v4l2_buf);
                if (ret != 0) {
                        PDEBUG(D_STREAM, "read dqbuf err %d", ret);
                        return ret;
                }

                /* if the process slept for more than 1 second,
                 * get a newer frame */
                frame = &gspca_dev->frame[v4l2_buf.index];
                if (--n < 0)
                        break;                  /* avoid infinite loop */
                if (frame->v4l2_buf.timestamp.tv_sec >= timestamp.tv_sec)
                        break;
                ret = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
                if (ret != 0) {
                        PDEBUG(D_STREAM, "read qbuf err %d", ret);
                        return ret;
                }
        }

        /* copy the frame */
        if (count > frame->v4l2_buf.bytesused)
                count = frame->v4l2_buf.bytesused;
        ret = copy_to_user(data, frame->data, count);
        if (ret != 0) {
                PERR("read cp to user lack %d / %zd", ret, count);
                ret = -EFAULT;
                goto out;
        }
        ret = count;
out:
        /* in each case, requeue the buffer */
        ret2 = vidioc_qbuf(file, gspca_dev, &v4l2_buf);
        if (ret2 != 0)
                return ret2;
        return ret;
}

static struct v4l2_file_operations dev_fops = {
        .owner = THIS_MODULE,
        .open = dev_open,
        .release = dev_close,
        .read = dev_read,
        .mmap = dev_mmap,
        .unlocked_ioctl = video_ioctl2,
        .poll   = dev_poll,
};

static const struct v4l2_ioctl_ops dev_ioctl_ops = {
        .vidioc_querycap        = vidioc_querycap,
        .vidioc_dqbuf           = vidioc_dqbuf,
        .vidioc_qbuf            = vidioc_qbuf,
        .vidioc_enum_fmt_vid_cap = vidioc_enum_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap = vidioc_try_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap   = vidioc_g_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap   = vidioc_s_fmt_vid_cap,
        .vidioc_streamon        = vidioc_streamon,
        .vidioc_enum_input      = vidioc_enum_input,
        .vidioc_g_input         = vidioc_g_input,
        .vidioc_s_input         = vidioc_s_input,
        .vidioc_reqbufs         = vidioc_reqbufs,
        .vidioc_querybuf        = vidioc_querybuf,
        .vidioc_streamoff       = vidioc_streamoff,
        .vidioc_g_jpegcomp      = vidioc_g_jpegcomp,
        .vidioc_s_jpegcomp      = vidioc_s_jpegcomp,
        .vidioc_g_parm          = vidioc_g_parm,
        .vidioc_s_parm          = vidioc_s_parm,
        .vidioc_enum_framesizes = vidioc_enum_framesizes,
        .vidioc_enum_frameintervals = vidioc_enum_frameintervals,
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .vidioc_g_chip_info     = vidioc_g_chip_info,
        .vidioc_g_register      = vidioc_g_register,
        .vidioc_s_register      = vidioc_s_register,
#endif
        .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
        .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static const struct video_device gspca_template = {
        .name = "gspca main driver",
        .fops = &dev_fops,
        .ioctl_ops = &dev_ioctl_ops,
        .release = video_device_release_empty, /* We use v4l2_dev.release */
};

/*
 * probe and create a new gspca device
 *
 * This function must be called by the sub-driver when it is
 * called for probing a new device.
 */
int gspca_dev_probe2(struct usb_interface *intf,

                const struct usb_device_id *id,
                const struct sd_desc *sd_desc,
                int dev_size,
                struct module *module)
{
        struct gspca_dev *gspca_dev;
        struct usb_device *dev = interface_to_usbdev(intf);
        int ret;

        pr_info("%s-" GSPCA_VERSION " probing %04x:%04x\n",
                sd_desc->name, id->idVendor, id->idProduct);

        /* create the device */
        if (dev_size < sizeof *gspca_dev)
                dev_size = sizeof *gspca_dev;
        gspca_dev = kzalloc(dev_size, GFP_KERNEL);
        if (!gspca_dev) {
                pr_err("couldn't kzalloc gspca struct\n");
                return -ENOMEM;
        }
        gspca_dev->usb_buf = kmalloc(USB_BUF_SZ, GFP_KERNEL);
        if (!gspca_dev->usb_buf) {
                pr_err("out of memory\n");
                ret = -ENOMEM;
                goto out;
        }
        gspca_dev->dev = dev;
        gspca_dev->iface = intf->cur_altsetting->desc.bInterfaceNumber;

        /* check if any audio device */
        if (dev->actconfig->desc.bNumInterfaces != 1) {
                int i;
                struct usb_interface *intf2;

                for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
                        intf2 = dev->actconfig->interface[i];
                        if (intf2 != NULL
                         && intf2->altsetting != NULL
                         && intf2->altsetting->desc.bInterfaceClass ==
                                         USB_CLASS_AUDIO) {
                                gspca_dev->audio = 1;
                                break;
                        }
                }
        }

        gspca_dev->v4l2_dev.release = gspca_release;
        ret = v4l2_device_register(&intf->dev, &gspca_dev->v4l2_dev);
        if (ret)
                goto out;
        gspca_dev->sd_desc = sd_desc;
        gspca_dev->nbufread = 2;
        gspca_dev->empty_packet = -1;   /* don't check the empty packets */
        gspca_dev->vdev = gspca_template;
        gspca_dev->vdev.v4l2_dev = &gspca_dev->v4l2_dev;
        video_set_drvdata(&gspca_dev->vdev, gspca_dev);
        set_bit(V4L2_FL_USE_FH_PRIO, &gspca_dev->vdev.flags);
        gspca_dev->module = module;
        gspca_dev->present = 1;

        mutex_init(&gspca_dev->usb_lock);
        gspca_dev->vdev.lock = &gspca_dev->usb_lock;
        mutex_init(&gspca_dev->queue_lock);
        init_waitqueue_head(&gspca_dev->wq);

        /* configure the subdriver and initialize the USB device */
        ret = sd_desc->config(gspca_dev, id);
        if (ret < 0)
                goto out;
        ret = sd_desc->init(gspca_dev);
        if (ret < 0)
                goto out;
        if (sd_desc->init_controls)
                ret = sd_desc->init_controls(gspca_dev);
        if (ret < 0)
                goto out;
        gspca_set_default_mode(gspca_dev);

        ret = gspca_input_connect(gspca_dev);
        if (ret)
                goto out;

        /*
         * Don't take usb_lock for these ioctls. This improves latency if
         * usb_lock is taken for a long time, e.g. when changing a control
         * value, and a new frame is ready to be dequeued.
         */
        v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_DQBUF);
        v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_QBUF);
        v4l2_disable_ioctl_locking(&gspca_dev->vdev, VIDIOC_QUERYBUF);
#ifdef CONFIG_VIDEO_ADV_DEBUG
        if (!gspca_dev->sd_desc->get_register)
                v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_DBG_G_REGISTER);
        if (!gspca_dev->sd_desc->set_register)
                v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_DBG_S_REGISTER);
#endif
        if (!gspca_dev->sd_desc->get_jcomp)
                v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_G_JPEGCOMP);
        if (!gspca_dev->sd_desc->set_jcomp)
                v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_S_JPEGCOMP);

        /* init video stuff */
        ret = video_register_device(&gspca_dev->vdev,
                                  VFL_TYPE_GRABBER,
                                  -1);
        if (ret < 0) {
                pr_err("video_register_device err %d\n", ret);
                goto out;
        }

        usb_set_intfdata(intf, gspca_dev);
        PDEBUG(D_PROBE, "%s created", video_device_node_name(&gspca_dev->vdev));

        gspca_input_create_urb(gspca_dev);

        return 0;
out:
#if IS_ENABLED(CONFIG_INPUT)
        if (gspca_dev->input_dev)
                input_unregister_device(gspca_dev->input_dev);
#endif
        v4l2_ctrl_handler_free(gspca_dev->vdev.ctrl_handler);
        kfree(gspca_dev->usb_buf);
        kfree(gspca_dev);
        return ret;
}
EXPORT_SYMBOL(gspca_dev_probe2);

/* same function as the previous one, but check the interface */
int gspca_dev_probe(struct usb_interface *intf,
                const struct usb_device_id *id,
                const struct sd_desc *sd_desc,
                int dev_size,
                struct module *module)
{
        struct usb_device *dev = interface_to_usbdev(intf);

        /* we don't handle multi-config cameras */
        if (dev->descriptor.bNumConfigurations != 1) {
                pr_err("%04x:%04x too many config\n",
                       id->idVendor, id->idProduct);
                return -ENODEV;
        }

        /* the USB video interface must be the first one */
        if (dev->actconfig->desc.bNumInterfaces != 1
         && intf->cur_altsetting->desc.bInterfaceNumber != 0)
                return -ENODEV;

        return gspca_dev_probe2(intf, id, sd_desc, dev_size, module);
}
EXPORT_SYMBOL(gspca_dev_probe);

/*
 * USB disconnection
 *
 * This function must be called by the sub-driver
 * when the device disconnects, after the specific resources are freed.
 */
void gspca_disconnect(struct usb_interface *intf)
{
        struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
#if IS_ENABLED(CONFIG_INPUT)
        struct input_dev *input_dev;
#endif

        PDEBUG(D_PROBE, "%s disconnect",
                video_device_node_name(&gspca_dev->vdev));

        mutex_lock(&gspca_dev->usb_lock);

        gspca_dev->present = 0;
        destroy_urbs(gspca_dev);

#if IS_ENABLED(CONFIG_INPUT)
        gspca_input_destroy_urb(gspca_dev);
        input_dev = gspca_dev->input_dev;
        if (input_dev) {
                gspca_dev->input_dev = NULL;
                input_unregister_device(input_dev);
        }
#endif
        /* Free subdriver's streaming resources / stop sd workqueue(s) */
        if (gspca_dev->sd_desc->stop0 && gspca_dev->streaming)
                gspca_dev->sd_desc->stop0(gspca_dev);
        gspca_dev->streaming = 0;
        gspca_dev->dev = NULL;
        wake_up_interruptible(&gspca_dev->wq);

        v4l2_device_disconnect(&gspca_dev->v4l2_dev);
        video_unregister_device(&gspca_dev->vdev);

        mutex_unlock(&gspca_dev->usb_lock);

        /* (this will call gspca_release() immediately or on last close) */
        v4l2_device_put(&gspca_dev->v4l2_dev);
}
EXPORT_SYMBOL(gspca_disconnect);

#ifdef CONFIG_PM
int gspca_suspend(struct usb_interface *intf, pm_message_t message)
{
        struct gspca_dev *gspca_dev = usb_get_intfdata(intf);

        gspca_input_destroy_urb(gspca_dev);

        if (!gspca_dev->streaming)
                return 0;

        mutex_lock(&gspca_dev->usb_lock);
        gspca_dev->frozen = 1;          /* avoid urb error messages */
        gspca_dev->usb_err = 0;
        if (gspca_dev->sd_desc->stopN)
                gspca_dev->sd_desc->stopN(gspca_dev);
        destroy_urbs(gspca_dev);
        gspca_set_alt0(gspca_dev);
        if (gspca_dev->sd_desc->stop0)
                gspca_dev->sd_desc->stop0(gspca_dev);
        mutex_unlock(&gspca_dev->usb_lock);

        return 0;
}
EXPORT_SYMBOL(gspca_suspend);

int gspca_resume(struct usb_interface *intf)
{
        struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
        int streaming, ret = 0;

        mutex_lock(&gspca_dev->usb_lock);
        gspca_dev->frozen = 0;
        gspca_dev->usb_err = 0;
        gspca_dev->sd_desc->init(gspca_dev);
        /*
         * Most subdrivers send all ctrl values on sd_start and thus
         * only write to the device registers on s_ctrl when streaming ->
         * Clear streaming to avoid setting all ctrls twice.
         */
        streaming = gspca_dev->streaming;
        gspca_dev->streaming = 0;
        if (streaming)
                ret = gspca_init_transfer(gspca_dev);
        else
                gspca_input_create_urb(gspca_dev);
        mutex_unlock(&gspca_dev->usb_lock);

        return ret;
}
EXPORT_SYMBOL(gspca_resume);
#endif

/* -- module insert / remove -- */
static int __init gspca_init(void)
{
        pr_info("v" GSPCA_VERSION " registered\n");
        return 0;
}
static void __exit gspca_exit(void)
{
}

module_init(gspca_init);
module_exit(gspca_exit);

module_param_named(debug, gspca_debug, int, 0644);
MODULE_PARM_DESC(debug,
                "1:probe 2:config 3:stream 4:frame 5:packet 6:usbi 7:usbo");