text: /*
   * stk-webcam.c : Driver for Syntek 1125 USB webcam controller
   *
   * Copyright (C) 2006 Nicolas VIVIEN
   * Copyright 2007-2008 Jaime Velasco Juan <jsagarribay@gmail.com>
   *
   * Some parts are inspired from cafe_ccic.c
   * Copyright 2006-2007 Jonathan Corbet
   *
   * 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
   * any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/slab.h>
  
  #include <linux/dmi.h>
  #include <linux/usb.h>
  #include <linux/mm.h>
  #include <linux/vmalloc.h>
  #include <linux/videodev2.h>
  #include <media/v4l2-common.h>
  #include <media/v4l2-ioctl.h>
  #include <media/v4l2-event.h>
  
  #include "stk-webcam.h"
  
  
  static int hflip = -1;
  module_param(hflip, int, 0444);
  MODULE_PARM_DESC(hflip, "Horizontal image flip (mirror). Defaults to 0");
  
  static int vflip = -1;
  module_param(vflip, int, 0444);
  MODULE_PARM_DESC(vflip, "Vertical image flip. Defaults to 0");
  
  static int debug;
  module_param(debug, int, 0444);
  MODULE_PARM_DESC(debug, "Debug v4l ioctls. Defaults to 0");
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Jaime Velasco Juan <jsagarribay@gmail.com> and Nicolas VIVIEN");
  MODULE_DESCRIPTION("Syntek DC1125 webcam driver");
  
  /* Some cameras have audio interfaces, we aren't interested in those */
  static struct usb_device_id stkwebcam_table[] = {
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x174f, 0xa311, 0xff, 0xff, 0xff) },
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x05e1, 0x0501, 0xff, 0xff, 0xff) },
  	{ }
  };
  MODULE_DEVICE_TABLE(usb, stkwebcam_table);
  
  /*
   * The stk webcam laptop module is mounted upside down in some laptops :(
   *
   * Some background information (thanks to Hans de Goede for providing this):
   *
   * 1) Once upon a time the stkwebcam driver was written
   *
   * 2) The webcam in question was used mostly in Asus laptop models, including
   * the laptop of the original author of the driver, and in these models, in
   * typical Asus fashion (see the long long list for uvc cams inside v4l-utils),
   * they mounted the webcam-module the wrong way up. So the hflip and vflip
   * module options were given a default value of 1 (the correct value for
   * upside down mounted models)
   *
   * 3) Years later I got a bug report from a user with a laptop with stkwebcam,
   * where the module was actually mounted the right way up, and thus showed
   * upside down under Linux. So now I was facing the choice of 2 options:
   *
   * a) Add a not-upside-down list to stkwebcam, which overrules the default.
   *
   * b) Do it like all the other drivers do, and make the default right for
   *    cams mounted the proper way and add an upside-down model list, with
   *    models where we need to flip-by-default.
   *
   * Despite knowing that going b) would cause a period of pain where we were
   * building the table I opted to go for option b), since a) is just too ugly,
   * and worse different from how every other driver does it leading to
   * confusion in the long run. This change was made in kernel 3.6.
   *
   * So for any user report about upside-down images since kernel 3.6 ask them
   * to provide the output of 'sudo dmidecode' so the laptop can be added in
   * the table below.
   */
  static const struct dmi_system_id stk_upside_down_dmi_table[] = {
  	{
  		.ident = "ASUS G1",
  		.matches = {
  			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
  			DMI_MATCH(DMI_PRODUCT_NAME, "G1")
  		}
  	}, {
  		.ident = "ASUS F3JC",
  		.matches = {
  			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
  			DMI_MATCH(DMI_PRODUCT_NAME, "F3JC")
  		}
  	},
  	{
  		.ident = "T12Rg-H",
  		.matches = {
  			DMI_MATCH(DMI_SYS_VENDOR, "HCL Infosystems Limited"),
  			DMI_MATCH(DMI_PRODUCT_NAME, "T12Rg-H")
  		}
  	},
  	{}
  };
  
  
  /*
   * Basic stuff
   */
  int stk_camera_write_reg(struct stk_camera *dev, u16 index, u8 value)
  {
  	struct usb_device *udev = dev->udev;
  	int ret;
  
  	ret =  usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
  			0x01,
  			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
  			value,
  			index,
  			NULL,
  			0,
  			500);
  	if (ret < 0)
  		return ret;
  	else
  		return 0;
  }
  
  int stk_camera_read_reg(struct stk_camera *dev, u16 index, int *value)
  {
  	struct usb_device *udev = dev->udev;
  	int ret;
  
  	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
  			0x00,
  			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
  			0x00,
  			index,
  			(u8 *) value,
  			sizeof(u8),
  			500);
  	if (ret < 0)
  		return ret;
  	else
  		return 0;
  }
  
  static int stk_start_stream(struct stk_camera *dev)
  {
  	int value;
  	int i, ret;
  	int value_116, value_117;
  
  	if (!is_present(dev))
  		return -ENODEV;
  	if (!is_memallocd(dev) || !is_initialised(dev)) {
  		STK_ERROR("FIXME: Buffers are not allocated\n");
  		return -EFAULT;
  	}
  	ret = usb_set_interface(dev->udev, 0, 5);
  
  	if (ret < 0)
  		STK_ERROR("usb_set_interface failed !\n");
  	if (stk_sensor_wakeup(dev))
  		STK_ERROR("error awaking the sensor\n");
  
  	stk_camera_read_reg(dev, 0x0116, &value_116);
  	stk_camera_read_reg(dev, 0x0117, &value_117);
  
  	stk_camera_write_reg(dev, 0x0116, 0x0000);
  	stk_camera_write_reg(dev, 0x0117, 0x0000);
  
  	stk_camera_read_reg(dev, 0x0100, &value);
  	stk_camera_write_reg(dev, 0x0100, value | 0x80);
  
  	stk_camera_write_reg(dev, 0x0116, value_116);
  	stk_camera_write_reg(dev, 0x0117, value_117);
  	for (i = 0; i < MAX_ISO_BUFS; i++) {
  		if (dev->isobufs[i].urb) {
  			ret = usb_submit_urb(dev->isobufs[i].urb, GFP_KERNEL);
  			atomic_inc(&dev->urbs_used);
  			if (ret)
  				return ret;
  		}
  	}
  	set_streaming(dev);
  	return 0;
  }
  
  static int stk_stop_stream(struct stk_camera *dev)
  {
  	int value;
  	int i;
  	if (is_present(dev)) {
  		stk_camera_read_reg(dev, 0x0100, &value);
  		stk_camera_write_reg(dev, 0x0100, value & ~0x80);
  		if (dev->isobufs != NULL) {
  			for (i = 0; i < MAX_ISO_BUFS; i++) {
  				if (dev->isobufs[i].urb)
  					usb_kill_urb(dev->isobufs[i].urb);
  			}
  		}
  		unset_streaming(dev);
  
  		if (usb_set_interface(dev->udev, 0, 0))
  			STK_ERROR("usb_set_interface failed !\n");
  		if (stk_sensor_sleep(dev))
  			STK_ERROR("error suspending the sensor\n");
  	}
  	return 0;
  }
  
  /*
   * This seems to be the shortest init sequence we
   * must do in order to find the sensor
   * Bit 5 of reg. 0x0000 here is important, when reset to 0 the sensor
   * is also reset. Maybe powers down it?
   * Rest of values don't make a difference
   */
  
  static struct regval stk1125_initvals[] = {
  	/*TODO: What means this sequence? */
  	{0x0000, 0x24},
  	{0x0100, 0x21},
  	{0x0002, 0x68},
  	{0x0003, 0x80},
  	{0x0005, 0x00},
  	{0x0007, 0x03},
  	{0x000d, 0x00},
  	{0x000f, 0x02},
  	{0x0300, 0x12},
  	{0x0350, 0x41},
  	{0x0351, 0x00},
  	{0x0352, 0x00},
  	{0x0353, 0x00},
  	{0x0018, 0x10},
  	{0x0019, 0x00},
  	{0x001b, 0x0e},
  	{0x001c, 0x46},
  	{0x0300, 0x80},
  	{0x001a, 0x04},
  	{0x0110, 0x00},
  	{0x0111, 0x00},
  	{0x0112, 0x00},
  	{0x0113, 0x00},
  
  	{0xffff, 0xff},
  };
  
  
  static int stk_initialise(struct stk_camera *dev)
  {
  	struct regval *rv;
  	int ret;
  	if (!is_present(dev))
  		return -ENODEV;
  	if (is_initialised(dev))
  		return 0;
  	rv = stk1125_initvals;
  	while (rv->reg != 0xffff) {
  		ret = stk_camera_write_reg(dev, rv->reg, rv->val);
  		if (ret)
  			return ret;
  		rv++;
  	}
  	if (stk_sensor_init(dev) == 0) {
  		set_initialised(dev);
  		return 0;
  	} else
  		return -1;
  }
  
  /* *********************************************** */
  /*
   * This function is called as an URB transfert is complete (Isochronous pipe).
   * So, the traitement is done in interrupt time, so it has be fast, not crash,
   * and not stall. Neat.
   */
  static void stk_isoc_handler(struct urb *urb)
  {
  	int i;
  	int ret;
  	int framelen;
  	unsigned long flags;
  
  	unsigned char *fill = NULL;
  	unsigned char *iso_buf = NULL;
  
  	struct stk_camera *dev;
  	struct stk_sio_buffer *fb;
  
  	dev = (struct stk_camera *) urb->context;
  
  	if (dev == NULL) {
  		STK_ERROR("isoc_handler called with NULL device !\n");
  		return;
  	}
  
  	if (urb->status == -ENOENT || urb->status == -ECONNRESET
  		|| urb->status == -ESHUTDOWN) {
  		atomic_dec(&dev->urbs_used);
  		return;
  	}
  
  	spin_lock_irqsave(&dev->spinlock, flags);
  
  	if (urb->status != -EINPROGRESS && urb->status != 0) {
  		STK_ERROR("isoc_handler: urb->status == %d\n", urb->status);
  		goto resubmit;
  	}
  
  	if (list_empty(&dev->sio_avail)) {
  		/*FIXME Stop streaming after a while */
  		(void) (printk_ratelimit() &&
  		STK_ERROR("isoc_handler without available buffer!\n"));
  		goto resubmit;
  	}
  	fb = list_first_entry(&dev->sio_avail,
  			struct stk_sio_buffer, list);
  	fill = fb->buffer + fb->v4lbuf.bytesused;
  
  	for (i = 0; i < urb->number_of_packets; i++) {
  		if (urb->iso_frame_desc[i].status != 0) {
  			if (urb->iso_frame_desc[i].status != -EXDEV)
  				STK_ERROR("Frame %d has error %d\n", i,
  					urb->iso_frame_desc[i].status);
  			continue;
  		}
  		framelen = urb->iso_frame_desc[i].actual_length;
  		iso_buf = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
  
  		if (framelen <= 4)
  			continue; /* no data */
  
  		/*
  		 * we found something informational from there
  		 * the isoc frames have to type of headers
  		 * type1: 00 xx 00 00 or 20 xx 00 00
  		 * type2: 80 xx 00 00 00 00 00 00 or a0 xx 00 00 00 00 00 00
  		 * xx is a sequencer which has never been seen over 0x3f
  		 * imho data written down looks like bayer, i see similarities
  		 * after every 640 bytes
  		 */
  		if (*iso_buf & 0x80) {
  			framelen -= 8;
  			iso_buf += 8;
  			/* This marks a new frame */
  			if (fb->v4lbuf.bytesused != 0
  				&& fb->v4lbuf.bytesused != dev->frame_size) {
  				(void) (printk_ratelimit() &&
  				STK_ERROR("frame %d, "
  					"bytesused=%d, skipping\n",
  					i, fb->v4lbuf.bytesused));
  				fb->v4lbuf.bytesused = 0;
  				fill = fb->buffer;
  			} else if (fb->v4lbuf.bytesused == dev->frame_size) {
  				if (list_is_singular(&dev->sio_avail)) {
  					/* Always reuse the last buffer */
  					fb->v4lbuf.bytesused = 0;
  					fill = fb->buffer;
  				} else {
  					list_move_tail(dev->sio_avail.next,
  						&dev->sio_full);
  					wake_up(&dev->wait_frame);
  					fb = list_first_entry(&dev->sio_avail,
  						struct stk_sio_buffer, list);
  					fb->v4lbuf.bytesused = 0;
  					fill = fb->buffer;
  				}
  			}
  		} else {
  			framelen -= 4;
  			iso_buf += 4;
  		}
  
  		/* Our buffer is full !!! */
  		if (framelen + fb->v4lbuf.bytesused > dev->frame_size) {
  			(void) (printk_ratelimit() &&
  			STK_ERROR("Frame buffer overflow, lost sync\n"));
  			/*FIXME Do something here? */
  			continue;
  		}
  		spin_unlock_irqrestore(&dev->spinlock, flags);
  		memcpy(fill, iso_buf, framelen);
  		spin_lock_irqsave(&dev->spinlock, flags);
  		fill += framelen;
  
  		/* New size of our buffer */
  		fb->v4lbuf.bytesused += framelen;
  	}
  
  resubmit:
  	spin_unlock_irqrestore(&dev->spinlock, flags);
  	urb->dev = dev->udev;
  	ret = usb_submit_urb(urb, GFP_ATOMIC);
  	if (ret != 0) {
  		STK_ERROR("Error (%d) re-submitting urb in stk_isoc_handler.\n",
  			ret);
  	}
  }
  
  /* -------------------------------------------- */
  
  static int stk_prepare_iso(struct stk_camera *dev)
  {
  	void *kbuf;
  	int i, j;
  	struct urb *urb;
  	struct usb_device *udev;
  
  	if (dev == NULL)
  		return -ENXIO;
  	udev = dev->udev;
  
  	if (dev->isobufs)
  		STK_ERROR("isobufs already allocated. Bad\n");
  	else
  		dev->isobufs = kcalloc(MAX_ISO_BUFS, sizeof(*dev->isobufs),
  				       GFP_KERNEL);
  	if (dev->isobufs == NULL) {
  		STK_ERROR("Unable to allocate iso buffers\n");
  		return -ENOMEM;
  	}
  	for (i = 0; i < MAX_ISO_BUFS; i++) {
  		if (dev->isobufs[i].data == NULL) {
  			kbuf = kzalloc(ISO_BUFFER_SIZE, GFP_KERNEL);
  			if (kbuf == NULL) {
  				STK_ERROR("Failed to allocate iso buffer %d\n",
  					i);
  				goto isobufs_out;
  			}
  			dev->isobufs[i].data = kbuf;
  		} else
  			STK_ERROR("isobuf data already allocated\n");
  		if (dev->isobufs[i].urb == NULL) {
  			urb = usb_alloc_urb(ISO_FRAMES_PER_DESC, GFP_KERNEL);
  			if (urb == NULL) {
  				STK_ERROR("Failed to allocate URB %d\n", i);
  				goto isobufs_out;
  			}
  			dev->isobufs[i].urb = urb;
  		} else {
  			STK_ERROR("Killing URB\n");
  			usb_kill_urb(dev->isobufs[i].urb);
  			urb = dev->isobufs[i].urb;
  		}
  		urb->interval = 1;
  		urb->dev = udev;
  		urb->pipe = usb_rcvisocpipe(udev, dev->isoc_ep);
  		urb->transfer_flags = URB_ISO_ASAP;
  		urb->transfer_buffer = dev->isobufs[i].data;
  		urb->transfer_buffer_length = ISO_BUFFER_SIZE;
  		urb->complete = stk_isoc_handler;
  		urb->context = dev;
  		urb->start_frame = 0;
  		urb->number_of_packets = ISO_FRAMES_PER_DESC;
  
  		for (j = 0; j < ISO_FRAMES_PER_DESC; j++) {
  			urb->iso_frame_desc[j].offset = j * ISO_MAX_FRAME_SIZE;
  			urb->iso_frame_desc[j].length = ISO_MAX_FRAME_SIZE;
  		}
  	}
  	set_memallocd(dev);
  	return 0;
  
  isobufs_out:
  	for (i = 0; i < MAX_ISO_BUFS && dev->isobufs[i].data; i++)
  		kfree(dev->isobufs[i].data);
  	for (i = 0; i < MAX_ISO_BUFS && dev->isobufs[i].urb; i++)
  		usb_free_urb(dev->isobufs[i].urb);
  	kfree(dev->isobufs);
  	dev->isobufs = NULL;
  	return -ENOMEM;
  }
  
  static void stk_clean_iso(struct stk_camera *dev)
  {
  	int i;
  
  	if (dev == NULL || dev->isobufs == NULL)
  		return;
  
  	for (i = 0; i < MAX_ISO_BUFS; i++) {
  		struct urb *urb;
  
  		urb = dev->isobufs[i].urb;
  		if (urb) {
  			if (atomic_read(&dev->urbs_used) && is_present(dev))
  				usb_kill_urb(urb);
  			usb_free_urb(urb);
  		}
  		kfree(dev->isobufs[i].data);
  	}
  	kfree(dev->isobufs);
  	dev->isobufs = NULL;
  	unset_memallocd(dev);
  }
  
  static int stk_setup_siobuf(struct stk_camera *dev, int index)
  {
  	struct stk_sio_buffer *buf = dev->sio_bufs + index;
  	INIT_LIST_HEAD(&buf->list);
  	buf->v4lbuf.length = PAGE_ALIGN(dev->frame_size);
  	buf->buffer = vmalloc_user(buf->v4lbuf.length);
  	if (buf->buffer == NULL)
  		return -ENOMEM;
  	buf->mapcount = 0;
  	buf->dev = dev;
  	buf->v4lbuf.index = index;
  	buf->v4lbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
  	buf->v4lbuf.flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
  	buf->v4lbuf.field = V4L2_FIELD_NONE;
  	buf->v4lbuf.memory = V4L2_MEMORY_MMAP;
  	buf->v4lbuf.m.offset = 2*index*buf->v4lbuf.length;
  	return 0;
  }
  
  static int stk_free_sio_buffers(struct stk_camera *dev)
  {
  	int i;
  	int nbufs;
  	unsigned long flags;
  	if (dev->n_sbufs == 0 || dev->sio_bufs == NULL)
  		return 0;
  	/*
  	* If any buffers are mapped, we cannot free them at all.
  	*/
  	for (i = 0; i < dev->n_sbufs; i++) {
  		if (dev->sio_bufs[i].mapcount > 0)
  			return -EBUSY;
  	}
  	/*
  	* OK, let's do it.
  	*/
  	spin_lock_irqsave(&dev->spinlock, flags);
  	INIT_LIST_HEAD(&dev->sio_avail);
  	INIT_LIST_HEAD(&dev->sio_full);
  	nbufs = dev->n_sbufs;
  	dev->n_sbufs = 0;
  	spin_unlock_irqrestore(&dev->spinlock, flags);
  	for (i = 0; i < nbufs; i++) {
  		if (dev->sio_bufs[i].buffer != NULL)
  			vfree(dev->sio_bufs[i].buffer);
  	}
  	kfree(dev->sio_bufs);
  	dev->sio_bufs = NULL;
  	return 0;
  }
  
  static int stk_prepare_sio_buffers(struct stk_camera *dev, unsigned n_sbufs)
  {
  	int i;
  	if (dev->sio_bufs != NULL)
  		STK_ERROR("sio_bufs already allocated\n");
  	else {
  		dev->sio_bufs = kzalloc(n_sbufs * sizeof(struct stk_sio_buffer),
  				GFP_KERNEL);
  		if (dev->sio_bufs == NULL)
  			return -ENOMEM;
  		for (i = 0; i < n_sbufs; i++) {
  			if (stk_setup_siobuf(dev, i))
  				return (dev->n_sbufs > 1 ? 0 : -ENOMEM);
  			dev->n_sbufs = i+1;
  		}
  	}
  	return 0;
  }
  
  static int stk_allocate_buffers(struct stk_camera *dev, unsigned n_sbufs)
  {
  	int err;
  	err = stk_prepare_iso(dev);
  	if (err) {
  		stk_clean_iso(dev);
  		return err;
  	}
  	err = stk_prepare_sio_buffers(dev, n_sbufs);
  	if (err) {
  		stk_free_sio_buffers(dev);
  		return err;
  	}
  	return 0;
  }
  
  static void stk_free_buffers(struct stk_camera *dev)
  {
  	stk_clean_iso(dev);
  	stk_free_sio_buffers(dev);
  }
  /* -------------------------------------------- */
  
  /* v4l file operations */
  
  static int v4l_stk_open(struct file *fp)
  {
  	struct stk_camera *dev = video_drvdata(fp);
  	int err;
  
  	if (dev == NULL || !is_present(dev))
  		return -ENXIO;
  
  	if (mutex_lock_interruptible(&dev->lock))
  		return -ERESTARTSYS;
  	if (!dev->first_init)
  		stk_camera_write_reg(dev, 0x0, 0x24);
  	else
  		dev->first_init = 0;
  
  	err = v4l2_fh_open(fp);
  	if (!err)
  		usb_autopm_get_interface(dev->interface);
  	mutex_unlock(&dev->lock);
  	return err;
  }
  
  static int v4l_stk_release(struct file *fp)
  {
  	struct stk_camera *dev = video_drvdata(fp);
  
  	mutex_lock(&dev->lock);
  	if (dev->owner == fp) {
  		stk_stop_stream(dev);
  		stk_free_buffers(dev);
  		stk_camera_write_reg(dev, 0x0, 0x49); /* turn off the LED */
  		unset_initialised(dev);
  		dev->owner = NULL;
  	}
  
  	if (is_present(dev))
  		usb_autopm_put_interface(dev->interface);
  	mutex_unlock(&dev->lock);
  	return v4l2_fh_release(fp);
  }
  
  static ssize_t stk_read(struct file *fp, char __user *buf,
  		size_t count, loff_t *f_pos)
  {
  	int i;
  	int ret;
  	unsigned long flags;
  	struct stk_sio_buffer *sbuf;
  	struct stk_camera *dev = video_drvdata(fp);
  
  	if (!is_present(dev))
  		return -EIO;
  	if (dev->owner && (!dev->reading || dev->owner != fp))
  		return -EBUSY;
  	dev->owner = fp;
  	if (!is_streaming(dev)) {
  		if (stk_initialise(dev)
  			|| stk_allocate_buffers(dev, 3)
  			|| stk_start_stream(dev))
  			return -ENOMEM;
  		dev->reading = 1;
  		spin_lock_irqsave(&dev->spinlock, flags);
  		for (i = 0; i < dev->n_sbufs; i++) {
  			list_add_tail(&dev->sio_bufs[i].list, &dev->sio_avail);
  			dev->sio_bufs[i].v4lbuf.flags = V4L2_BUF_FLAG_QUEUED;
  		}
  		spin_unlock_irqrestore(&dev->spinlock, flags);
  	}
  	if (*f_pos == 0) {
  		if (fp->f_flags & O_NONBLOCK && list_empty(&dev->sio_full))
  			return -EWOULDBLOCK;
  		ret = wait_event_interruptible(dev->wait_frame,
  			!list_empty(&dev->sio_full) || !is_present(dev));
  		if (ret)
  			return ret;
  		if (!is_present(dev))
  			return -EIO;
  	}
  	if (count + *f_pos > dev->frame_size)
  		count = dev->frame_size - *f_pos;
  	spin_lock_irqsave(&dev->spinlock, flags);
  	if (list_empty(&dev->sio_full)) {
  		spin_unlock_irqrestore(&dev->spinlock, flags);
  		STK_ERROR("BUG: No siobufs ready\n");
  		return 0;
  	}
  	sbuf = list_first_entry(&dev->sio_full, struct stk_sio_buffer, list);
  	spin_unlock_irqrestore(&dev->spinlock, flags);
  
  	if (copy_to_user(buf, sbuf->buffer + *f_pos, count))
  		return -EFAULT;
  
  	*f_pos += count;
  
  	if (*f_pos >= dev->frame_size) {
  		*f_pos = 0;
  		spin_lock_irqsave(&dev->spinlock, flags);
  		list_move_tail(&sbuf->list, &dev->sio_avail);
  		spin_unlock_irqrestore(&dev->spinlock, flags);
  	}
  	return count;
  }
  
  static ssize_t v4l_stk_read(struct file *fp, char __user *buf,
  		size_t count, loff_t *f_pos)
  {
  	struct stk_camera *dev = video_drvdata(fp);
  	int ret;
  
  	if (mutex_lock_interruptible(&dev->lock))
  		return -ERESTARTSYS;
  	ret = stk_read(fp, buf, count, f_pos);
  	mutex_unlock(&dev->lock);
  	return ret;
  }
  
  static unsigned int v4l_stk_poll(struct file *fp, poll_table *wait)
  {
  	struct stk_camera *dev = video_drvdata(fp);
  	unsigned res = v4l2_ctrl_poll(fp, wait);
  
  	poll_wait(fp, &dev->wait_frame, wait);
  
  	if (!is_present(dev))
  		return POLLERR;
  
  	if (!list_empty(&dev->sio_full))
  		return res | POLLIN | POLLRDNORM;
  
  	return res;
  }
  
  
  static void stk_v4l_vm_open(struct vm_area_struct *vma)
  {
  	struct stk_sio_buffer *sbuf = vma->vm_private_data;
  	sbuf->mapcount++;
  }
  static void stk_v4l_vm_close(struct vm_area_struct *vma)
  {
  	struct stk_sio_buffer *sbuf = vma->vm_private_data;
  	sbuf->mapcount--;
  	if (sbuf->mapcount == 0)
  		sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_MAPPED;
  }
  static const struct vm_operations_struct stk_v4l_vm_ops = {
  	.open = stk_v4l_vm_open,
  	.close = stk_v4l_vm_close
  };
  
  static int v4l_stk_mmap(struct file *fp, struct vm_area_struct *vma)
  {
  	unsigned int i;
  	int ret;
  	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
  	struct stk_camera *dev = video_drvdata(fp);
  	struct stk_sio_buffer *sbuf = NULL;
  
  	if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED))
  		return -EINVAL;
  
  	for (i = 0; i < dev->n_sbufs; i++) {
  		if (dev->sio_bufs[i].v4lbuf.m.offset == offset) {
  			sbuf = dev->sio_bufs + i;
  			break;
  		}
  	}
  	if (sbuf == NULL)
  		return -EINVAL;
  	ret = remap_vmalloc_range(vma, sbuf->buffer, 0);
  	if (ret)
  		return ret;
  	vma->vm_flags |= VM_DONTEXPAND;
  	vma->vm_private_data = sbuf;
  	vma->vm_ops = &stk_v4l_vm_ops;
  	sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_MAPPED;
  	stk_v4l_vm_open(vma);
  	return 0;
  }
  
  /* v4l ioctl handlers */
  
  static int stk_vidioc_querycap(struct file *filp,
  		void *priv, struct v4l2_capability *cap)
  {
  	struct stk_camera *dev = video_drvdata(filp);
  
  	strcpy(cap->driver, "stk");
  	strcpy(cap->card, "stk");
  	usb_make_path(dev->udev, cap->bus_info, sizeof(cap->bus_info));
  
  	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE
  		| V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;
  	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
  	return 0;
  }
  
  static int stk_vidioc_enum_input(struct file *filp,
  		void *priv, struct v4l2_input *input)
  {
  	if (input->index != 0)
  		return -EINVAL;
  
  	strcpy(input->name, "Syntek USB Camera");
  	input->type = V4L2_INPUT_TYPE_CAMERA;
  	return 0;
  }
  
  
  static int stk_vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
  {
  	*i = 0;
  	return 0;
  }
  
  static int stk_vidioc_s_input(struct file *filp, void *priv, unsigned int i)
  {
  	return i ? -EINVAL : 0;
  }
  
  static int stk_s_ctrl(struct v4l2_ctrl *ctrl)
  {
  	struct stk_camera *dev =
  		container_of(ctrl->handler, struct stk_camera, hdl);
  
  	switch (ctrl->id) {
  	case V4L2_CID_BRIGHTNESS:
  		return stk_sensor_set_brightness(dev, ctrl->val);
  	case V4L2_CID_HFLIP:
  		if (dmi_check_system(stk_upside_down_dmi_table))
  			dev->vsettings.hflip = !ctrl->val;
  		else
  			dev->vsettings.hflip = ctrl->val;
  		return 0;
  	case V4L2_CID_VFLIP:
  		if (dmi_check_system(stk_upside_down_dmi_table))
  			dev->vsettings.vflip = !ctrl->val;
  		else
  			dev->vsettings.vflip = ctrl->val;
  		return 0;
  	default:
  		return -EINVAL;
  	}
  	return 0;
  }
  
  
  static int stk_vidioc_enum_fmt_vid_cap(struct file *filp,
  		void *priv, struct v4l2_fmtdesc *fmtd)
  {
  	switch (fmtd->index) {
  	case 0:
  		fmtd->pixelformat = V4L2_PIX_FMT_RGB565;
  		strcpy(fmtd->description, "r5g6b5");
  		break;
  	case 1:
  		fmtd->pixelformat = V4L2_PIX_FMT_RGB565X;
  		strcpy(fmtd->description, "r5g6b5BE");
  		break;
  	case 2:
  		fmtd->pixelformat = V4L2_PIX_FMT_UYVY;
  		strcpy(fmtd->description, "yuv4:2:2");
  		break;
  	case 3:
  		fmtd->pixelformat = V4L2_PIX_FMT_SBGGR8;
  		strcpy(fmtd->description, "Raw bayer");
  		break;
  	case 4:
  		fmtd->pixelformat = V4L2_PIX_FMT_YUYV;
  		strcpy(fmtd->description, "yuv4:2:2");
  		break;
  	default:
  		return -EINVAL;
  	}
  	return 0;
  }
  
  static struct stk_size {
  	unsigned w;
  	unsigned h;
  	enum stk_mode m;
  } stk_sizes[] = {
  	{ .w = 1280, .h = 1024, .m = MODE_SXGA, },
  	{ .w = 640,  .h = 480,  .m = MODE_VGA,  },
  	{ .w = 352,  .h = 288,  .m = MODE_CIF,  },
  	{ .w = 320,  .h = 240,  .m = MODE_QVGA, },
  	{ .w = 176,  .h = 144,  .m = MODE_QCIF, },
  };
  
  static int stk_vidioc_g_fmt_vid_cap(struct file *filp,
  		void *priv, struct v4l2_format *f)
  {
  	struct v4l2_pix_format *pix_format = &f->fmt.pix;
  	struct stk_camera *dev = video_drvdata(filp);
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(stk_sizes) &&
  			stk_sizes[i].m != dev->vsettings.mode; i++)
  		;
  	if (i == ARRAY_SIZE(stk_sizes)) {
  		STK_ERROR("ERROR: mode invalid\n");
  		return -EINVAL;
  	}
  	pix_format->width = stk_sizes[i].w;
  	pix_format->height = stk_sizes[i].h;
  	pix_format->field = V4L2_FIELD_NONE;
  	pix_format->colorspace = V4L2_COLORSPACE_SRGB;
  	pix_format->pixelformat = dev->vsettings.palette;
  	if (dev->vsettings.palette == V4L2_PIX_FMT_SBGGR8)
  		pix_format->bytesperline = pix_format->width;
  	else
  		pix_format->bytesperline = 2 * pix_format->width;
  	pix_format->sizeimage = pix_format->bytesperline
  				* pix_format->height;
  	return 0;
  }
  
  static int stk_try_fmt_vid_cap(struct file *filp,
  		struct v4l2_format *fmtd, int *idx)
  {
  	int i;
  	switch (fmtd->fmt.pix.pixelformat) {
  	case V4L2_PIX_FMT_RGB565:
  	case V4L2_PIX_FMT_RGB565X:
  	case V4L2_PIX_FMT_UYVY:
  	case V4L2_PIX_FMT_YUYV:
  	case V4L2_PIX_FMT_SBGGR8:
  		break;
  	default:
  		return -EINVAL;
  	}
  	for (i = 1; i < ARRAY_SIZE(stk_sizes); i++) {
  		if (fmtd->fmt.pix.width > stk_sizes[i].w)
  			break;
  	}
  	if (i == ARRAY_SIZE(stk_sizes)
  		|| (abs(fmtd->fmt.pix.width - stk_sizes[i-1].w)
  			< abs(fmtd->fmt.pix.width - stk_sizes[i].w))) {
  		fmtd->fmt.pix.height = stk_sizes[i-1].h;
  		fmtd->fmt.pix.width = stk_sizes[i-1].w;
  		if (idx)
  			*idx = i - 1;
  	} else {
  		fmtd->fmt.pix.height = stk_sizes[i].h;
  		fmtd->fmt.pix.width = stk_sizes[i].w;
  		if (idx)
  			*idx = i;
  	}
  
  	fmtd->fmt.pix.field = V4L2_FIELD_NONE;
  	fmtd->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
  	if (fmtd->fmt.pix.pixelformat == V4L2_PIX_FMT_SBGGR8)
  		fmtd->fmt.pix.bytesperline = fmtd->fmt.pix.width;
  	else
  		fmtd->fmt.pix.bytesperline = 2 * fmtd->fmt.pix.width;
  	fmtd->fmt.pix.sizeimage = fmtd->fmt.pix.bytesperline
  		* fmtd->fmt.pix.height;
  	return 0;
  }
  
  static int stk_vidioc_try_fmt_vid_cap(struct file *filp,
  		void *priv, struct v4l2_format *fmtd)
  {
  	return stk_try_fmt_vid_cap(filp, fmtd, NULL);
  }
  
  static int stk_setup_format(struct stk_camera *dev)
  {
  	int i = 0;
  	int depth;
  	if (dev->vsettings.palette == V4L2_PIX_FMT_SBGGR8)
  		depth = 1;
  	else
  		depth = 2;
  	while (i < ARRAY_SIZE(stk_sizes) &&
  			stk_sizes[i].m != dev->vsettings.mode)
  		i++;
  	if (i == ARRAY_SIZE(stk_sizes)) {
  		STK_ERROR("Something is broken in %s\n", __func__);
  		return -EFAULT;
  	}
  	/* This registers controls some timings, not sure of what. */
  	stk_camera_write_reg(dev, 0x001b, 0x0e);
  	if (dev->vsettings.mode == MODE_SXGA)
  		stk_camera_write_reg(dev, 0x001c, 0x0e);
  	else
  		stk_camera_write_reg(dev, 0x001c, 0x46);
  	/*
  	 * Registers 0x0115 0x0114 are the size of each line (bytes),
  	 * regs 0x0117 0x0116 are the heigth of the image.
  	 */
  	stk_camera_write_reg(dev, 0x0115,
  		((stk_sizes[i].w * depth) >> 8) & 0xff);
  	stk_camera_write_reg(dev, 0x0114,
  		(stk_sizes[i].w * depth) & 0xff);
  	stk_camera_write_reg(dev, 0x0117,
  		(stk_sizes[i].h >> 8) & 0xff);
  	stk_camera_write_reg(dev, 0x0116,
  		stk_sizes[i].h & 0xff);
  	return stk_sensor_configure(dev);
  }
  
  static int stk_vidioc_s_fmt_vid_cap(struct file *filp,
  		void *priv, struct v4l2_format *fmtd)
  {
  	int ret;
  	int idx;
  	struct stk_camera *dev = video_drvdata(filp);
  
  	if (dev == NULL)
  		return -ENODEV;
  	if (!is_present(dev))
  		return -ENODEV;
  	if (is_streaming(dev))
  		return -EBUSY;
  	if (dev->owner)
  		return -EBUSY;
  	ret = stk_try_fmt_vid_cap(filp, fmtd, &idx);
  	if (ret)
  		return ret;
  
  	dev->vsettings.palette = fmtd->fmt.pix.pixelformat;
  	stk_free_buffers(dev);
  	dev->frame_size = fmtd->fmt.pix.sizeimage;
  	dev->vsettings.mode = stk_sizes[idx].m;
  
  	stk_initialise(dev);
  	return stk_setup_format(dev);
  }
  
  static int stk_vidioc_reqbufs(struct file *filp,
  		void *priv, struct v4l2_requestbuffers *rb)
  {
  	struct stk_camera *dev = video_drvdata(filp);
  
  	if (dev == NULL)
  		return -ENODEV;
  	if (rb->memory != V4L2_MEMORY_MMAP)
  		return -EINVAL;
  	if (is_streaming(dev)
  		|| (dev->owner && dev->owner != filp))
  		return -EBUSY;
  	stk_free_buffers(dev);
  	if (rb->count == 0) {
  		stk_camera_write_reg(dev, 0x0, 0x49); /* turn off the LED */
  		unset_initialised(dev);
  		dev->owner = NULL;
  		return 0;
  	}
  	dev->owner = filp;
  
  	/*FIXME If they ask for zero, we must stop streaming and free */
  	if (rb->count < 3)
  		rb->count = 3;
  	/* Arbitrary limit */
  	else if (rb->count > 5)
  		rb->count = 5;
  
  	stk_allocate_buffers(dev, rb->count);
  	rb->count = dev->n_sbufs;
  	return 0;
  }
  
  static int stk_vidioc_querybuf(struct file *filp,
  		void *priv, struct v4l2_buffer *buf)
  {
  	struct stk_camera *dev = video_drvdata(filp);
  	struct stk_sio_buffer *sbuf;
  
  	if (buf->index >= dev->n_sbufs)
  		return -EINVAL;
  	sbuf = dev->sio_bufs + buf->index;
  	*buf = sbuf->v4lbuf;
  	return 0;
  }
  
  static int stk_vidioc_qbuf(struct file *filp,
  		void *priv, struct v4l2_buffer *buf)
  {
  	struct stk_camera *dev = video_drvdata(filp);
  	struct stk_sio_buffer *sbuf;
  	unsigned long flags;
  
  	if (buf->memory != V4L2_MEMORY_MMAP)
  		return -EINVAL;
  
  	if (buf->index >= dev->n_sbufs)
  		return -EINVAL;
  	sbuf = dev->sio_bufs + buf->index;
  	if (sbuf->v4lbuf.flags & V4L2_BUF_FLAG_QUEUED)
  		return 0;
  	sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_QUEUED;
  	sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_DONE;
  	spin_lock_irqsave(&dev->spinlock, flags);
  	list_add_tail(&sbuf->list, &dev->sio_avail);
  	*buf = sbuf->v4lbuf;
  	spin_unlock_irqrestore(&dev->spinlock, flags);
  	return 0;
  }
  
  static int stk_vidioc_dqbuf(struct file *filp,
  		void *priv, struct v4l2_buffer *buf)
  {
  	struct stk_camera *dev = video_drvdata(filp);
  	struct stk_sio_buffer *sbuf;
  	unsigned long flags;
  	int ret;
  
  	if (!is_streaming(dev))
  		return -EINVAL;
  
  	if (filp->f_flags & O_NONBLOCK && list_empty(&dev->sio_full))
  		return -EWOULDBLOCK;
  	ret = wait_event_interruptible(dev->wait_frame,
  		!list_empty(&dev->sio_full) || !is_present(dev));
  	if (ret)
  		return ret;
  	if (!is_present(dev))
  		return -EIO;
  
  	spin_lock_irqsave(&dev->spinlock, flags);
  	sbuf = list_first_entry(&dev->sio_full, struct stk_sio_buffer, list);
  	list_del_init(&sbuf->list);
  	spin_unlock_irqrestore(&dev->spinlock, flags);
  	sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_QUEUED;
  	sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_DONE;
  	sbuf->v4lbuf.sequence = ++dev->sequence;
  	v4l2_get_timestamp(&sbuf->v4lbuf.timestamp);
  
  	*buf = sbuf->v4lbuf;
  	return 0;
  }
  
  static int stk_vidioc_streamon(struct file *filp,
  		void *priv, enum v4l2_buf_type type)
  {
  	struct stk_camera *dev = video_drvdata(filp);
  	if (is_streaming(dev))
  		return 0;
  	if (dev->sio_bufs == NULL)
  		return -EINVAL;
  	dev->sequence = 0;
  	return stk_start_stream(dev);
  }
  
  static int stk_vidioc_streamoff(struct file *filp,
  		void *priv, enum v4l2_buf_type type)
  {
  	struct stk_camera *dev = video_drvdata(filp);
  	unsigned long flags;
  	int i;
  	stk_stop_stream(dev);
  	spin_lock_irqsave(&dev->spinlock, flags);
  	INIT_LIST_HEAD(&dev->sio_avail);
  	INIT_LIST_HEAD(&dev->sio_full);
  	for (i = 0; i < dev->n_sbufs; i++) {
  		INIT_LIST_HEAD(&dev->sio_bufs[i].list);
  		dev->sio_bufs[i].v4lbuf.flags = 0;
  	}
  	spin_unlock_irqrestore(&dev->spinlock, flags);
  	return 0;
  }
  
  
  static int stk_vidioc_g_parm(struct file *filp,
  		void *priv, struct v4l2_streamparm *sp)
  {
  	/*FIXME This is not correct */
  	sp->parm.capture.timeperframe.numerator = 1;
  	sp->parm.capture.timeperframe.denominator = 30;
  	sp->parm.capture.readbuffers = 2;
  	return 0;
  }
  
  static int stk_vidioc_enum_framesizes(struct file *filp,
  		void *priv, struct v4l2_frmsizeenum *frms)
  {
  	if (frms->index >= ARRAY_SIZE(stk_sizes))
  		return -EINVAL;
  	switch (frms->pixel_format) {
  	case V4L2_PIX_FMT_RGB565:
  	case V4L2_PIX_FMT_RGB565X:
  	case V4L2_PIX_FMT_UYVY:
  	case V4L2_PIX_FMT_YUYV:
  	case V4L2_PIX_FMT_SBGGR8:
  		frms->type = V4L2_FRMSIZE_TYPE_DISCRETE;
  		frms->discrete.width = stk_sizes[frms->index].w;
  		frms->discrete.height = stk_sizes[frms->index].h;
  		return 0;
  	default: return -EINVAL;
  	}
  }
  
  static const struct v4l2_ctrl_ops stk_ctrl_ops = {
  	.s_ctrl = stk_s_ctrl,
  };
  
  static struct v4l2_file_operations v4l_stk_fops = {
  	.owner = THIS_MODULE,
  	.open = v4l_stk_open,
  	.release = v4l_stk_release,
  	.read = v4l_stk_read,
  	.poll = v4l_stk_poll,
  	.mmap = v4l_stk_mmap,
  	.unlocked_ioctl = video_ioctl2,
  };
  
  static const struct v4l2_ioctl_ops v4l_stk_ioctl_ops = {
  	.vidioc_querycap = stk_vidioc_querycap,
  	.vidioc_enum_fmt_vid_cap = stk_vidioc_enum_fmt_vid_cap,
  	.vidioc_try_fmt_vid_cap = stk_vidioc_try_fmt_vid_cap,
  	.vidioc_s_fmt_vid_cap = stk_vidioc_s_fmt_vid_cap,
  	.vidioc_g_fmt_vid_cap = stk_vidioc_g_fmt_vid_cap,
  	.vidioc_enum_input = stk_vidioc_enum_input,
  	.vidioc_s_input = stk_vidioc_s_input,
  	.vidioc_g_input = stk_vidioc_g_input,
  	.vidioc_reqbufs = stk_vidioc_reqbufs,
  	.vidioc_querybuf = stk_vidioc_querybuf,
  	.vidioc_qbuf = stk_vidioc_qbuf,
  	.vidioc_dqbuf = stk_vidioc_dqbuf,
  	.vidioc_streamon = stk_vidioc_streamon,
  	.vidioc_streamoff = stk_vidioc_streamoff,
  	.vidioc_g_parm = stk_vidioc_g_parm,
  	.vidioc_enum_framesizes = stk_vidioc_enum_framesizes,
  	.vidioc_log_status = v4l2_ctrl_log_status,
  	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
  	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
  };
  
  static void stk_v4l_dev_release(struct video_device *vd)
  {
  	struct stk_camera *dev = vdev_to_camera(vd);
  
  	if (dev->sio_bufs != NULL || dev->isobufs != NULL)
  		STK_ERROR("We are leaking memory\n");
  	usb_put_intf(dev->interface);
  	kfree(dev);
  }
  
  static struct video_device stk_v4l_data = {
  	.name = "stkwebcam",
  	.fops = &v4l_stk_fops,
  	.ioctl_ops = &v4l_stk_ioctl_ops,
  	.release = stk_v4l_dev_release,
  };
  
  
  static int stk_register_video_device(struct stk_camera *dev)
  {
  	int err;
  
  	dev->vdev = stk_v4l_data;
  	dev->vdev.lock = &dev->lock;
  	dev->vdev.debug = debug;
  	dev->vdev.v4l2_dev = &dev->v4l2_dev;
  	video_set_drvdata(&dev->vdev, dev);
  	err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
  	if (err)
  		STK_ERROR("v4l registration failed\n");
  	else
  		STK_INFO("Syntek USB2.0 Camera is now controlling device %s\n",
  			 video_device_node_name(&dev->vdev));
  	return err;
  }
  
  
  /* USB Stuff */
  
  static int stk_camera_probe(struct usb_interface *interface,
  		const struct usb_device_id *id)
  {
  	struct v4l2_ctrl_handler *hdl;
  	int err = 0;
  	int i;
  
  	struct stk_camera *dev = NULL;
  	struct usb_device *udev = interface_to_usbdev(interface);
  	struct usb_host_interface *iface_desc;
  	struct usb_endpoint_descriptor *endpoint;
  
  	dev = kzalloc(sizeof(struct stk_camera), GFP_KERNEL);
  	if (dev == NULL) {
  		STK_ERROR("Out of memory !\n");
  		return -ENOMEM;
  	}
  	err = v4l2_device_register(&interface->dev, &dev->v4l2_dev);
  	if (err < 0) {
  		dev_err(&udev->dev, "couldn't register v4l2_device\n");
  		kfree(dev);
  		return err;
  	}
  	hdl = &dev->hdl;
  	v4l2_ctrl_handler_init(hdl, 3);
  	v4l2_ctrl_new_std(hdl, &stk_ctrl_ops,
  			  V4L2_CID_BRIGHTNESS, 0, 0xff, 0x1, 0x60);
  	v4l2_ctrl_new_std(hdl, &stk_ctrl_ops,
  			  V4L2_CID_HFLIP, 0, 1, 1, 1);
  	v4l2_ctrl_new_std(hdl, &stk_ctrl_ops,
  			  V4L2_CID_VFLIP, 0, 1, 1, 1);
  	if (hdl->error) {
  		err = hdl->error;
  		dev_err(&udev->dev, "couldn't register control\n");
  		goto error;
  	}
  	dev->v4l2_dev.ctrl_handler = hdl;
  
  	spin_lock_init(&dev->spinlock);
  	mutex_init(&dev->lock);
  	init_waitqueue_head(&dev->wait_frame);
  	dev->first_init = 1; /* webcam LED management */
  
  	dev->udev = udev;
  	dev->interface = interface;
  	usb_get_intf(interface);
  
  	if (hflip != -1)
  		dev->vsettings.hflip = hflip;
  	else if (dmi_check_system(stk_upside_down_dmi_table))
  		dev->vsettings.hflip = 1;
  	else
  		dev->vsettings.hflip = 0;
  	if (vflip != -1)
  		dev->vsettings.vflip = vflip;
  	else if (dmi_check_system(stk_upside_down_dmi_table))
  		dev->vsettings.vflip = 1;
  	else
  		dev->vsettings.vflip = 0;
  	dev->n_sbufs = 0;
  	set_present(dev);
  
  	/* Set up the endpoint information
  	 * use only the first isoc-in endpoint
  	 * for the current alternate setting */
  	iface_desc = interface->cur_altsetting;
  
  	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
  		endpoint = &iface_desc->endpoint[i].desc;
  
  		if (!dev->isoc_ep
  			&& usb_endpoint_is_isoc_in(endpoint)) {
  			/* we found an isoc in endpoint */
  			dev->isoc_ep = usb_endpoint_num(endpoint);
  			break;
  		}
  	}
  	if (!dev->isoc_ep) {
  		STK_ERROR("Could not find isoc-in endpoint");
  		err = -ENODEV;
  		goto error;
  	}
  	dev->vsettings.palette = V4L2_PIX_FMT_RGB565;
  	dev->vsettings.mode = MODE_VGA;
  	dev->frame_size = 640 * 480 * 2;
  
  	INIT_LIST_HEAD(&dev->sio_avail);
  	INIT_LIST_HEAD(&dev->sio_full);
  
  	usb_set_intfdata(interface, dev);
  
  	err = stk_register_video_device(dev);
  	if (err)
  		goto error;
  
  	return 0;
  
  error:
  	v4l2_ctrl_handler_free(hdl);
  	v4l2_device_unregister(&dev->v4l2_dev);
  	kfree(dev);
  	return err;
  }
  
  static void stk_camera_disconnect(struct usb_interface *interface)
  {
  	struct stk_camera *dev = usb_get_intfdata(interface);
  
  	usb_set_intfdata(interface, NULL);
  	unset_present(dev);
  
  	wake_up_interruptible(&dev->wait_frame);
  
  	STK_INFO("Syntek USB2.0 Camera release resources device %s\n",
  		 video_device_node_name(&dev->vdev));
  
  	video_unregister_device(&dev->vdev);
  	v4l2_ctrl_handler_free(&dev->hdl);
  	v4l2_device_unregister(&dev->v4l2_dev);
  }
  
  #ifdef CONFIG_PM
  static int stk_camera_suspend(struct usb_interface *intf, pm_message_t message)
  {
  	struct stk_camera *dev = usb_get_intfdata(intf);
  	if (is_streaming(dev)) {
  		stk_stop_stream(dev);
  		/* yes, this is ugly */
  		set_streaming(dev);
  	}
  	return 0;
  }
  
  static int stk_camera_resume(struct usb_interface *intf)
  {
  	struct stk_camera *dev = usb_get_intfdata(intf);
  	if (!is_initialised(dev))
  		return 0;
  	unset_initialised(dev);
  	stk_initialise(dev);
  	stk_camera_write_reg(dev, 0x0, 0x49);
  	stk_setup_format(dev);
  	if (is_streaming(dev))
  		stk_start_stream(dev);
  	return 0;
  }
  #endif
  
  static struct usb_driver stk_camera_driver = {
  	.name = "stkwebcam",
  	.probe = stk_camera_probe,
  	.disconnect = stk_camera_disconnect,
  	.id_table = stkwebcam_table,
  #ifdef CONFIG_PM
  	.suspend = stk_camera_suspend,
  	.resume = stk_camera_resume,
  #endif
  };
  
  module_usb_driver(stk_camera_driver);
  