1 files changed, 2456 insertions, 0 deletions

diff --git a/drivers/media/usb/gspca/gspca.c b/drivers/media/usb/gspca/gspca.c
new file mode 100644
index 000000000000..d4e8343f5b10
--- /dev/null
+++ b/drivers/media/usb/gspca/gspca.c
@@ -0,0 +1,2456 @@
+/*
+ * 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 defined(CONFIG_INPUT) || defined(CONFIG_INPUT_MODULE)
+#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);
+
+#ifdef GSPCA_DEBUG
+int gspca_debug = D_ERR | D_PROBE;
+EXPORT_SYMBOL(gspca_debug);
+
+static void PDEBUG_MODE(char *txt, __u32 pixfmt, int w, int h)
+{
+	if ((pixfmt >> 24) >= '0' && (pixfmt >> 24) <= 'z') {
+		PDEBUG(D_CONF|D_STREAM, "%s %c%c%c%c %dx%d",
+			txt,
+			pixfmt & 0xff,
+			(pixfmt >> 8) & 0xff,
+			(pixfmt >> 16) & 0xff,
+			pixfmt >> 24,
+			w, h);
+	} else {
+		PDEBUG(D_CONF|D_STREAM, "%s 0x%08x %dx%d",
+			txt,
+			pixfmt,
+			w, h);
+	}
+}
+#else
+#define PDEBUG_MODE(txt, pixfmt, w, h)
+#endif
+
+/* 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 defined(CONFIG_INPUT) || defined(CONFIG_INPUT_MODULE)
+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) {
+			PDEBUG(D_ERR, "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:
+		PDEBUG(D_ERR, "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) {
+		PDEBUG(D_ERR, "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
+		PDEBUG(D_ERR|D_PACK, "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
+		PDEBUG(D_ERR|D_PACK, "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) {
+			PDEBUG(D_ERR|D_PACK, "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);
+		if (urb->transfer_buffer != NULL)
+			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:
+		PDEBUG(D_ERR|D_STREAM,
+			"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)
+{
+	struct gspca_ctrl *ctrl;
+	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;
+
+	/* set the current control values to their default values
+	 * which may have changed in sd_init() */
+	/* does nothing if ctrl_handler == NULL */
+	v4l2_ctrl_handler_setup(gspca_dev->vdev.ctrl_handler);
+	ctrl = gspca_dev->cam.ctrls;
+	if (ctrl != NULL) {
+		for (i = 0;
+		     i < gspca_dev->sd_desc->nctrls;
+		     i++, ctrl++)
+			ctrl->val = ctrl->def;
+	}
+}
+
+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_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,
+			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_g_chip_ident(struct file *file, void *priv,
+			struct v4l2_dbg_chip_ident *chip)
+{
+	struct gspca_dev *gspca_dev = video_drvdata(file);
+
+	gspca_dev->usb_err = 0;
+	return gspca_dev->sd_desc->get_chip_ident(gspca_dev, chip);
+}
+
+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;
+
+#ifdef GSPCA_DEBUG
+	if (gspca_debug & D_CONF)
+		PDEBUG_MODE("try fmt cap", fmt->fmt.pix.pixelformat, w, h);
+#endif
+	/* 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;
+/*		else
+			;		 * no chance, return this 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 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;
+
+#ifdef GSPCA_DEBUG
+	/* activate the v4l2 debug */
+	if (gspca_debug & D_V4L2)
+		gspca_dev->vdev.debug |= V4L2_DEBUG_IOCTL
+					| V4L2_DEBUG_IOCTL_ARG;
+	else
+		gspca_dev->vdev.debug &= ~(V4L2_DEBUG_IOCTL
+					| V4L2_DEBUG_IOCTL_ARG);
+#endif
+	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 get_ctrl(struct gspca_dev *gspca_dev,
+				   int id)
+{
+	const struct ctrl *ctrls;
+	int i;
+
+	for (i = 0, ctrls = gspca_dev->sd_desc->ctrls;
+	     i < gspca_dev->sd_desc->nctrls;
+	     i++, ctrls++) {
+		if (gspca_dev->ctrl_dis & (1 << i))
+			continue;
+		if (id == ctrls->qctrl.id)
+			return i;
+	}
+	return -1;
+}
+
+static int vidioc_queryctrl(struct file *file, void *priv,
+			   struct v4l2_queryctrl *q_ctrl)
+{
+	struct gspca_dev *gspca_dev = video_drvdata(file);
+	const struct ctrl *ctrls;
+	struct gspca_ctrl *gspca_ctrl;
+	int i, idx;
+	u32 id;
+
+	id = q_ctrl->id;
+	if (id & V4L2_CTRL_FLAG_NEXT_CTRL) {
+		id &= V4L2_CTRL_ID_MASK;
+		id++;
+		idx = -1;
+		for (i = 0; i < gspca_dev->sd_desc->nctrls; i++) {
+			if (gspca_dev->ctrl_dis & (1 << i))
+				continue;
+			if (gspca_dev->sd_desc->ctrls[i].qctrl.id < id)
+				continue;
+			if (idx >= 0
+			 && gspca_dev->sd_desc->ctrls[i].qctrl.id
+				    > gspca_dev->sd_desc->ctrls[idx].qctrl.id)
+				continue;
+			idx = i;
+		}
+	} else {
+		idx = get_ctrl(gspca_dev, id);
+	}
+	if (idx < 0)
+		return -EINVAL;
+	ctrls = &gspca_dev->sd_desc->ctrls[idx];
+	memcpy(q_ctrl, &ctrls->qctrl, sizeof *q_ctrl);
+	if (gspca_dev->cam.ctrls != NULL) {
+		gspca_ctrl = &gspca_dev->cam.ctrls[idx];
+		q_ctrl->default_value = gspca_ctrl->def;
+		q_ctrl->minimum = gspca_ctrl->min;
+		q_ctrl->maximum = gspca_ctrl->max;
+	}
+	if (gspca_dev->ctrl_inac & (1 << idx))
+		q_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE;
+	return 0;
+}
+
+static int vidioc_s_ctrl(struct file *file, void *priv,
+			 struct v4l2_control *ctrl)
+{
+	struct gspca_dev *gspca_dev = video_drvdata(file);
+	const struct ctrl *ctrls;
+	struct gspca_ctrl *gspca_ctrl;
+	int idx;
+
+	idx = get_ctrl(gspca_dev, ctrl->id);
+	if (idx < 0)
+		return -EINVAL;
+	if (gspca_dev->ctrl_inac & (1 << idx))
+		return -EINVAL;
+	ctrls = &gspca_dev->sd_desc->ctrls[idx];
+	if (gspca_dev->cam.ctrls != NULL) {
+		gspca_ctrl = &gspca_dev->cam.ctrls[idx];
+		if (ctrl->value < gspca_ctrl->min
+		    || ctrl->value > gspca_ctrl->max)
+			return -ERANGE;
+	} else {
+		gspca_ctrl = NULL;
+		if (ctrl->value < ctrls->qctrl.minimum
+		    || ctrl->value > ctrls->qctrl.maximum)
+			return -ERANGE;
+	}
+	PDEBUG(D_CONF, "set ctrl [%08x] = %d", ctrl->id, ctrl->value);
+	gspca_dev->usb_err = 0;
+	if (ctrls->set != NULL)
+		return ctrls->set(gspca_dev, ctrl->value);
+	if (gspca_ctrl != NULL) {
+		gspca_ctrl->val = ctrl->value;
+		if (ctrls->set_control != NULL
+		 && gspca_dev->streaming)
+			ctrls->set_control(gspca_dev);
+	}
+	return gspca_dev->usb_err;
+}
+
+static int vidioc_g_ctrl(struct file *file, void *priv,
+			 struct v4l2_control *ctrl)
+{
+	struct gspca_dev *gspca_dev = video_drvdata(file);
+	const struct ctrl *ctrls;
+	int idx;
+
+	idx = get_ctrl(gspca_dev, ctrl->id);
+	if (idx < 0)
+		return -EINVAL;
+	ctrls = &gspca_dev->sd_desc->ctrls[idx];
+
+	gspca_dev->usb_err = 0;
+	if (ctrls->get != NULL)
+		return ctrls->get(gspca_dev, &ctrl->value);
+	if (gspca_dev->cam.ctrls != NULL)
+		ctrl->value = gspca_dev->cam.ctrls[idx].val;
+	return 0;
+}
+
+static int vidioc_querymenu(struct file *file, void *priv,
+			    struct v4l2_querymenu *qmenu)
+{
+	struct gspca_dev *gspca_dev = video_drvdata(file);
+
+	if (!gspca_dev->sd_desc->querymenu)
+		return -ENOTTY;
+	return gspca_dev->sd_desc->querymenu(gspca_dev, qmenu);
+}
+
+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 < 0
+	    || 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;
+	}
+#ifdef GSPCA_DEBUG
+	if (gspca_debug & D_STREAM) {
+		PDEBUG_MODE("stream on OK",
+			gspca_dev->pixfmt,
+			gspca_dev->width,
+			gspca_dev->height);
+	}
+#endif
+	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,
+			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)) {
+			PDEBUG(D_ERR|D_STREAM,
+				"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) {
+		PDEBUG(D_ERR|D_STREAM,
+			"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_queryctrl	= vidioc_queryctrl,
+	.vidioc_g_ctrl		= vidioc_g_ctrl,
+	.vidioc_s_ctrl		= vidioc_s_ctrl,
+	.vidioc_querymenu	= vidioc_querymenu,
+	.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_register	= vidioc_g_register,
+	.vidioc_s_register	= vidioc_s_register,
+#endif
+	.vidioc_g_chip_ident	= vidioc_g_chip_ident,
+	.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 */
+};
+
+/* initialize the controls */
+static void ctrls_init(struct gspca_dev *gspca_dev)
+{
+	struct gspca_ctrl *ctrl;
+	int i;
+
+	for (i = 0, ctrl = gspca_dev->cam.ctrls;
+	     i < gspca_dev->sd_desc->nctrls;
+	     i++, ctrl++) {
+		ctrl->def = gspca_dev->sd_desc->ctrls[i].qctrl.default_value;
+		ctrl->val = ctrl->def;
+		ctrl->min = gspca_dev->sd_desc->ctrls[i].qctrl.minimum;
+		ctrl->max = gspca_dev->sd_desc->ctrls[i].qctrl.maximum;
+	}
+}
+
+/*
+ * 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;
+	if (gspca_dev->cam.ctrls != NULL)
+		ctrls_init(gspca_dev);
+	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);
+	if (!gspca_dev->sd_desc->get_chip_ident)
+		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_DBG_G_CHIP_IDENT);
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	if (!gspca_dev->sd_desc->get_chip_ident ||
+	    !gspca_dev->sd_desc->get_register)
+		v4l2_disable_ioctl(&gspca_dev->vdev, VIDIOC_DBG_G_REGISTER);
+	if (!gspca_dev->sd_desc->get_chip_ident ||
+	    !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 defined(CONFIG_INPUT) || defined(CONFIG_INPUT_MODULE)
+	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 defined(CONFIG_INPUT) || defined(CONFIG_INPUT_MODULE)
+	struct input_dev *input_dev;
+#endif
+
+	PDEBUG(D_PROBE, "%s disconnect",
+		video_device_node_name(&gspca_dev->vdev));
+
+	mutex_lock(&gspca_dev->usb_lock);
+
+	usb_set_intfdata(intf, NULL);
+	gspca_dev->dev = NULL;
+	gspca_dev->present = 0;
+	destroy_urbs(gspca_dev);
+
+#if defined(CONFIG_INPUT) || defined(CONFIG_INPUT_MODULE)
+	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;
+	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);
+
+	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_input_destroy_urb(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);
+	gspca_input_create_urb(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);
+	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);
+
+#ifdef GSPCA_DEBUG
+module_param_named(debug, gspca_debug, int, 0644);
+MODULE_PARM_DESC(debug,
+		"Debug (bit) 0x01:error 0x02:probe 0x04:config"
+		" 0x08:stream 0x10:frame 0x20:packet"
+		" 0x0100: v4l2");
+#endif