/*
 * 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 const 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, u8 *value)
{
        struct usb_device *udev = dev->udev;
        unsigned char *buf;
        int ret;

        buf = kmalloc(sizeof(u8), GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
                        0x00,
                        USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                        0x00,
                        index,
                        buf,
                        sizeof(u8),
                        500);
        if (ret >= 0)
                *value = *buf;

        kfree(buf);
        return ret;
}

static int stk_start_stream(struct stk_camera *dev)
{
        u8 value;
        int i, ret;
        u8 value_116, value_117;


        if (!is_present(dev))
                return -ENODEV;
        if (!is_memallocd(dev) || !is_initialised(dev)) {
                pr_err("FIXME: Buffers are not allocated\n");
                return -EFAULT;
        }
        ret = usb_set_interface(dev->udev, 0, 5);

        if (ret < 0)
                pr_err("usb_set_interface failed !\n");
        if (stk_sensor_wakeup(dev))
                pr_err("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)
{
        u8 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))
                        pr_err("usb_set_interface failed !\n");
                if (stk_sensor_sleep(dev))
                        pr_err("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) {
                pr_err("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) {
                pr_err("isoc_handler: urb->status == %d\n", urb->status);
                goto resubmit;
        }

        if (list_empty(&dev->sio_avail)) {
                /*FIXME Stop streaming after a while */
                pr_err_ratelimited("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)
                                pr_err("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) {
                                pr_err_ratelimited("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) {
                        pr_err_ratelimited("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) {
                pr_err("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)
                pr_err("isobufs already allocated. Bad\n");
        else
                dev->isobufs = kcalloc(MAX_ISO_BUFS, sizeof(*dev->isobufs),
                                       GFP_KERNEL);
        if (dev->isobufs == NULL) {
                pr_err("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) {
                                pr_err("Failed to allocate iso buffer %d\n", i);
                                goto isobufs_out;
                        }
                        dev->isobufs[i].data = kbuf;
                } else
                        pr_err("isobuf data already allocated\n");
                if (dev->isobufs[i].urb == NULL) {
                        urb = usb_alloc_urb(ISO_FRAMES_PER_DESC, GFP_KERNEL);
                        if (urb == NULL)
                                goto isobufs_out;
                        dev->isobufs[i].urb = urb;
                } else {
                        pr_err("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++)
                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)
                pr_err("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);
                pr_err("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)) {
                pr_err("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)) {
                pr_err("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 const 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)
                pr_err("We are leaking memory\n");
        usb_put_intf(dev->interface);
        kfree(dev);
}

static const 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.v4l2_dev = &dev->v4l2_dev;
        video_set_drvdata(&dev->vdev, dev);
        err = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
        if (err)
                pr_err("v4l registration failed\n");
        else
                pr_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) {
                pr_err("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) {
                pr_err("Could not find isoc-in endpoint\n");
                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);

        pr_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);