stk-webcam.c

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/*
 * stk-webcam.c : Driver for Syntek 1125 USB webcam controller
 *
 * Copyright (C) 2006 Nicolas VIVIEN
 * Copyright 2007-2008 Jaime Velasco Juan <[email protected]>
 *
 * 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/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 "stk-webcam.h"


static bool hflip;
module_param(hflip, bool, 0444);
MODULE_PARM_DESC(hflip, "Horizontal image flip (mirror). Defaults to 0");

static bool vflip;
module_param(vflip, bool, 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 <[email protected]> and Nicolas VIVIEN");
MODULE_DESCRIPTION("Syntek DC1125 webcam driver");


/* bool for webcam LED management */
int first_init = 1;

/* 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);

/*
 * 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.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;
    struct video_device *vdev;

    vdev = video_devdata(fp);
    dev = vdev_to_camera(vdev);

    if (dev == NULL || !is_present(dev))
        return -ENXIO;

    if (!first_init)
        stk_camera_write_reg(dev, 0x0, 0x24);
    else
        first_init = 0;

    fp->private_data = dev;
    usb_autopm_get_interface(dev->interface);

    return 0;
}

static int v4l_stk_release(struct file *fp)
{
    struct stk_camera *dev = fp->private_data;

    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);

    return 0;
}

static ssize_t v4l_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 = fp->private_data;

    if (!is_present(dev))
        return -EIO;
    if (dev->owner && 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;
        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 unsigned int v4l_stk_poll(struct file *fp, poll_table *wait)
{
    struct stk_camera *dev = fp->private_data;

    poll_wait(fp, &dev->wait_frame, wait);

    if (!is_present(dev))
        return POLLERR;

    if (!list_empty(&dev->sio_full))
        return POLLIN | POLLRDNORM;

    return 0;
}


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 = fp->private_data;
    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)
{
    strcpy(cap->driver, "stk");
    strcpy(cap->card, "stk");
    cap->version = DRIVER_VERSION_NUM;

    cap->capabilities = V4L2_CAP_VIDEO_CAPTURE
        | V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;
    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)
{
    if (i != 0)
        return -EINVAL;
    else
        return 0;
}

/* from vivi.c */
static int stk_vidioc_s_std(struct file *filp, void *priv, v4l2_std_id *a)
{
    return 0;
}

/* List of all V4Lv2 controls supported by the driver */
static struct v4l2_queryctrl stk_controls[] = {
    {
        .id      = V4L2_CID_BRIGHTNESS,
        .type    = V4L2_CTRL_TYPE_INTEGER,
        .name    = "Brightness",
        .minimum = 0,
        .maximum = 0xffff,
        .step    = 0x0100,
        .default_value = 0x6000,
    },
    {
        .id      = V4L2_CID_HFLIP,
        .type    = V4L2_CTRL_TYPE_BOOLEAN,
        .name    = "Horizontal Flip",
        .minimum = 0,
        .maximum = 1,
        .step    = 1,
        .default_value = 1,
    },
    {
        .id      = V4L2_CID_VFLIP,
        .type    = V4L2_CTRL_TYPE_BOOLEAN,
        .name    = "Vertical Flip",
        .minimum = 0,
        .maximum = 1,
        .step    = 1,
        .default_value = 1,
    },
};

static int stk_vidioc_queryctrl(struct file *filp,
        void *priv, struct v4l2_queryctrl *c)
{
    int i;
    int nbr;
    nbr = ARRAY_SIZE(stk_controls);

    for (i = 0; i < nbr; i++) {
        if (stk_controls[i].id == c->id) {
            memcpy(c, &stk_controls[i],
                sizeof(struct v4l2_queryctrl));
            return 0;
        }
    }
    return -EINVAL;
}

static int stk_vidioc_g_ctrl(struct file *filp,
        void *priv, struct v4l2_control *c)
{
    struct stk_camera *dev = priv;
    switch (c->id) {
    case V4L2_CID_BRIGHTNESS:
        c->value = dev->vsettings.brightness;
        break;
    case V4L2_CID_HFLIP:
        c->value = dev->vsettings.hflip;
        break;
    case V4L2_CID_VFLIP:
        c->value = dev->vsettings.vflip;
        break;
    default:
        return -EINVAL;
    }
    return 0;
}

static int stk_vidioc_s_ctrl(struct file *filp,
        void *priv, struct v4l2_control *c)
{
    struct stk_camera *dev = priv;
    switch (c->id) {
    case V4L2_CID_BRIGHTNESS:
        dev->vsettings.brightness = c->value;
        return stk_sensor_set_brightness(dev, c->value >> 8);
    case V4L2_CID_HFLIP:
        dev->vsettings.hflip = c->value;
        return 0;
    case V4L2_CID_VFLIP:
        dev->vsettings.vflip = c->value;
        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 = priv;
    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_vidioc_try_fmt_vid_cap(struct file *filp,
        void *priv, struct v4l2_format *fmtd)
{
    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;
        fmtd->fmt.pix.priv = i - 1;
    } else {
        fmtd->fmt.pix.height = stk_sizes[i].h;
        fmtd->fmt.pix.width = stk_sizes[i].w;
        fmtd->fmt.pix.priv = 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_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;
    struct stk_camera *dev = priv;

    if (dev == NULL)
        return -ENODEV;
    if (!is_present(dev))
        return -ENODEV;
    if (is_streaming(dev))
        return -EBUSY;
    if (dev->owner && dev->owner != filp)
        return -EBUSY;
    ret = stk_vidioc_try_fmt_vid_cap(filp, priv, fmtd);
    if (ret)
        return ret;
    dev->owner = filp;

    dev->vsettings.palette = fmtd->fmt.pix.pixelformat;
    stk_free_buffers(dev);
    dev->frame_size = fmtd->fmt.pix.sizeimage;
    dev->vsettings.mode = stk_sizes[fmtd->fmt.pix.priv].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 = priv;

    if (dev == NULL)
        return -ENODEV;
    if (rb->memory != V4L2_MEMORY_MMAP)
        return -EINVAL;
    if (is_streaming(dev)
        || (dev->owner && dev->owner != filp))
        return -EBUSY;
    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 = priv;
    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 = priv;
    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 = priv;
    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;
    do_gettimeofday(&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 = priv;
    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 = priv;
    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 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,
    .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_s_std = stk_vidioc_s_std,
    .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_queryctrl = stk_vidioc_queryctrl,
    .vidioc_g_ctrl = stk_vidioc_g_ctrl,
    .vidioc_s_ctrl = stk_vidioc_s_ctrl,
    .vidioc_g_parm = stk_vidioc_g_parm,
    .vidioc_enum_framesizes = stk_vidioc_enum_framesizes,
};

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",
    .tvnorms = V4L2_STD_UNKNOWN,
    .current_norm = V4L2_STD_UNKNOWN,
    .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.debug = debug;
    dev->vdev.parent = &dev->interface->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)
{
    int i;
    int err = 0;

    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;
    }

    spin_lock_init(&dev->spinlock);
    init_waitqueue_head(&dev->wait_frame);

    dev->udev = udev;
    dev->interface = interface;
    usb_get_intf(interface);

    dev->vsettings.vflip = vflip;
    dev->vsettings.hflip = hflip;
    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.brightness = 0x7fff;
    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:
    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);
}

#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);