vicam.c

h内核

}
static int
initialize_camera(struct vicam_camera *cam)
{
	const struct {
		u8 *data;
		u32 size;
	} firmware[] = {
		{ .data = setup1, .size = sizeof(setup1) },
		{ .data = setup2, .size = sizeof(setup2) },
		{ .data = setup3, .size = sizeof(setup3) },
		{ .data = setup4, .size = sizeof(setup4) },
		{ .data = setup5, .size = sizeof(setup5) },
		{ .data = setup3, .size = sizeof(setup3) },
		{ .data = NULL, .size = 0 }
	};

	int err, i;

	for (i = 0, err = 0; firmware[i].data && !err; i++) {
		memcpy(cam->cntrlbuf, firmware[i].data, firmware[i].size);

		err = send_control_msg(cam, 0xff, 0, 0,
				       cam->cntrlbuf, firmware[i].size);
	}

	return err;
}

static int
set_camera_power(struct vicam_camera *cam, int state)
{
	int status;

	if ((status = send_control_msg(cam, 0x50, state, 0, NULL, 0)) < 0)
		return status;

	if (state) {
		send_control_msg(cam, 0x55, 1, 0, NULL, 0);
	}

	return 0;
}

static int
vicam_ioctl(struct inode *inode, struct file *file, unsigned int ioctlnr, unsigned long arg)
{
	void __user *user_arg = (void __user *)arg;
	struct vicam_camera *cam = file->private_data;
	int retval = 0;

	if (!cam)
		return -ENODEV;

	switch (ioctlnr) {
		/* query capabilities */
	case VIDIOCGCAP:
		{
			struct video_capability b;

			DBG("VIDIOCGCAP\n");
			memset(&b, 0, sizeof(b));
			strcpy(b.name, "ViCam-based Camera");
			b.type = VID_TYPE_CAPTURE;
			b.channels = 1;
			b.audios = 0;
			b.maxwidth = 320;	/* VIDEOSIZE_CIF */
			b.maxheight = 240;
			b.minwidth = 320;	/* VIDEOSIZE_48_48 */
			b.minheight = 240;

			if (copy_to_user(user_arg, &b, sizeof(b)))
				retval = -EFAULT;

			break;
		}
		/* get/set video source - we are a camera and nothing else */
	case VIDIOCGCHAN:
		{
			struct video_channel v;

			DBG("VIDIOCGCHAN\n");
			if (copy_from_user(&v, user_arg, sizeof(v))) {
				retval = -EFAULT;
				break;
			}
			if (v.channel != 0) {
				retval = -EINVAL;
				break;
			}

			v.channel = 0;
			strcpy(v.name, "Camera");
			v.tuners = 0;
			v.flags = 0;
			v.type = VIDEO_TYPE_CAMERA;
			v.norm = 0;

			if (copy_to_user(user_arg, &v, sizeof(v)))
				retval = -EFAULT;
			break;
		}

	case VIDIOCSCHAN:
		{
			int v;

			if (copy_from_user(&v, user_arg, sizeof(v)))
				retval = -EFAULT;
			DBG("VIDIOCSCHAN %d\n", v);

			if (retval == 0 && v != 0)
				retval = -EINVAL;

			break;
		}

		/* image properties */
	case VIDIOCGPICT:
		{
			struct video_picture vp;
			DBG("VIDIOCGPICT\n");
			memset(&vp, 0, sizeof (struct video_picture));
			vp.brightness = cam->gain << 8;
			vp.depth = 24;
			vp.palette = VIDEO_PALETTE_RGB24;
			if (copy_to_user(user_arg, &vp, sizeof (struct video_picture)))
				retval = -EFAULT;
			break;
		}

	case VIDIOCSPICT:
		{
			struct video_picture vp;
			
			if (copy_from_user(&vp, user_arg, sizeof(vp))) {
				retval = -EFAULT;
				break;
			}
			
			DBG("VIDIOCSPICT depth = %d, pal = %d\n", vp.depth,
			    vp.palette);

			cam->gain = vp.brightness >> 8;

			if (vp.depth != 24
			    || vp.palette != VIDEO_PALETTE_RGB24)
				retval = -EINVAL;

			break;
		}

		/* get/set capture window */
	case VIDIOCGWIN:
		{
			struct video_window vw;
			vw.x = 0;
			vw.y = 0;
			vw.width = 320;
			vw.height = 240;
			vw.chromakey = 0;
			vw.flags = 0;
			vw.clips = NULL;
			vw.clipcount = 0;

			DBG("VIDIOCGWIN\n");

			if (copy_to_user(user_arg, (void *)&vw, sizeof(vw)))
				retval = -EFAULT;

			// I'm not sure what the deal with a capture window is, it is very poorly described
			// in the doc.  So I won't support it now.
			break;
		}

	case VIDIOCSWIN:
		{

			struct video_window vw;

			if (copy_from_user(&vw, user_arg, sizeof(vw))) {
				retval = -EFAULT;
				break;
			}

			DBG("VIDIOCSWIN %d x %d\n", vw.width, vw.height);
			
			if ( vw.width != 320 || vw.height != 240 )
				retval = -EFAULT;

			break;
		}

		/* mmap interface */
	case VIDIOCGMBUF:
		{
			struct video_mbuf vm;
			int i;

			DBG("VIDIOCGMBUF\n");
			memset(&vm, 0, sizeof (vm));
			vm.size =
			    VICAM_MAX_FRAME_SIZE * VICAM_FRAMES;
			vm.frames = VICAM_FRAMES;
			for (i = 0; i < VICAM_FRAMES; i++)
				vm.offsets[i] = VICAM_MAX_FRAME_SIZE * i;

			if (copy_to_user(user_arg, (void *)&vm, sizeof(vm)))
				retval = -EFAULT;

			break;
		}

	case VIDIOCMCAPTURE:
		{
			struct video_mmap vm;
			// int video_size;

			if (copy_from_user((void *)&vm, user_arg, sizeof(vm))) {
				retval = -EFAULT;
				break;
			}

			DBG("VIDIOCMCAPTURE frame=%d, height=%d, width=%d, format=%d.\n",vm.frame,vm.width,vm.height,vm.format);

			if ( vm.frame >= VICAM_FRAMES || vm.format != VIDEO_PALETTE_RGB24 )
				retval = -EINVAL;

			// in theory right here we'd start the image capturing
			// (fill in a bulk urb and submit it asynchronously)
			//
			// Instead we're going to do a total hack job for now and
			// retrieve the frame in VIDIOCSYNC

			break;
		}

	case VIDIOCSYNC:
		{
			int frame;

			if (copy_from_user((void *)&frame, user_arg, sizeof(int))) {
				retval = -EFAULT;
				break;
			}
			DBG("VIDIOCSYNC: %d\n", frame);

			read_frame(cam, frame);
			vicam_decode_color(cam->raw_image,
					   cam->framebuf +
					   frame * VICAM_MAX_FRAME_SIZE );

			break;
		}

		/* pointless to implement overlay with this camera */
	case VIDIOCCAPTURE:
	case VIDIOCGFBUF:
	case VIDIOCSFBUF:
	case VIDIOCKEY:
		retval = -EINVAL;
		break;

		/* tuner interface - we have none */
	case VIDIOCGTUNER:
	case VIDIOCSTUNER:
	case VIDIOCGFREQ:
	case VIDIOCSFREQ:
		retval = -EINVAL;
		break;

		/* audio interface - we have none */
	case VIDIOCGAUDIO:
	case VIDIOCSAUDIO:
		retval = -EINVAL;
		break;
	default:
		retval = -ENOIOCTLCMD;
		break;
	}

	return retval;
}

static int
vicam_open(struct inode *inode, struct file *file)
{
	struct video_device *dev = video_devdata(file);
	struct vicam_camera *cam =
	    (struct vicam_camera *) dev->priv;
	DBG("open\n");

	if (!cam) {
		printk(KERN_ERR
		       "vicam video_device improperly initialized");
	}

	/* the videodev_lock held above us protects us from
	 * simultaneous opens...for now. we probably shouldn't
	 * rely on this fact forever.
	 */

	if (cam->open_count > 0) {
		printk(KERN_INFO
		       "vicam_open called on already opened camera");
		return -EBUSY;
	}

	cam->raw_image = kmalloc(VICAM_MAX_READ_SIZE, GFP_KERNEL);
	if (!cam->raw_image) {
		return -ENOMEM;
	}

	cam->framebuf = rvmalloc(VICAM_MAX_FRAME_SIZE * VICAM_FRAMES);
	if (!cam->framebuf) {
		kfree(cam->raw_image);
		return -ENOMEM;
	}

	cam->cntrlbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (!cam->cntrlbuf) {
		kfree(cam->raw_image);
		rvfree(cam->framebuf, VICAM_MAX_FRAME_SIZE * VICAM_FRAMES);
		return -ENOMEM;
	}

	// First upload firmware, then turn the camera on

	if (!cam->is_initialized) {
		initialize_camera(cam);

		cam->is_initialized = 1;
	}

	set_camera_power(cam, 1);

	cam->needsDummyRead = 1;
	cam->open_count++;

	file->private_data = cam;	
	
	return 0;
}

static int 
vicam_close(struct inode *inode, struct file *file)
{
	struct vicam_camera *cam = file->private_data;
	int open_count;
	struct usb_device *udev;

	DBG("close\n");

	/* it's not the end of the world if
	 * we fail to turn the camera off.
	 */

	set_camera_power(cam, 0);

	kfree(cam->raw_image);
	rvfree(cam->framebuf, VICAM_MAX_FRAME_SIZE * VICAM_FRAMES);
	kfree(cam->cntrlbuf);

	down(&cam->cam_lock);

	cam->open_count--;
	open_count = cam->open_count;
	udev = cam->udev;

	up(&cam->cam_lock);

	if (!open_count && !udev) {
		kfree(cam);
	}

	return 0;
}

static void vicam_decode_color(const u8 *data, u8 *rgb)
{
	/* vicam_decode_color - Convert from Vicam Y-Cr-Cb to RGB
	 * Copyright (C) 2002 Monroe Williams ([e-mail])
	 */

	int i, prevY, nextY;

	prevY = 512;
	nextY = 512;

	data += VICAM_HEADER_SIZE;

	for( i = 0; i < 240; i++, data += 512 ) {
		const int y = ( i * 242 ) / 240;

		int j, prevX, nextX;
		int Y, Cr, Cb;

		if ( y == 242 - 1 ) {
			nextY = -512;
		}

		prevX = 1;
		nextX = 1;

		for ( j = 0; j < 320; j++, rgb += 3 ) {
			const int x = ( j * 512 ) / 320;
			const u8 * const src = &data[x];

			if ( x == 512 - 1 ) {
				nextX = -1;
			}

			Cr = ( src[prevX] - src[0] ) +
				( src[nextX] - src[0] );
			Cr /= 2;

			Cb = ( src[prevY] - src[prevX + prevY] ) +
				( src[prevY] - src[nextX + prevY] ) +
				( src[nextY] - src[prevX + nextY] ) +
				( src[nextY] - src[nextX + nextY] );
			Cb /= 4;

			Y = 1160 * ( src[0] + ( Cr / 2 ) - 16 );

			if ( i & 1 ) {
				int Ct = Cr;
				Cr = Cb;
				Cb = Ct;
			}

			if ( ( x ^ i ) & 1 ) {
				Cr = -Cr;
				Cb = -Cb;
			}

			rgb[0] = clamp( ( ( Y + ( 2017 * Cb ) ) +
					500 ) / 900, 0, 255 );
			rgb[1] = clamp( ( ( Y - ( 392 * Cb ) -
					  ( 813 * Cr ) ) +
					  500 ) / 1000, 0, 255 );
			rgb[2] = clamp( ( ( Y + ( 1594 * Cr ) ) +
					500 ) / 1300, 0, 255 );

			prevX = -1;
		}

		prevY = -512;
	}
}

static void
read_frame(struct vicam_camera *cam, int framenum)
{
	unsigned char *request = cam->cntrlbuf;
	int realShutter;
	int n;
	int actual_length;

	if (cam->needsDummyRead) {
		cam->needsDummyRead = 0;
		read_frame(cam, framenum);
	}

	memset(request, 0, 16);
	request[0] = cam->gain;	// 0 = 0% gain, FF = 100% gain

	request[1] = 0;	// 512x242 capture

	request[2] = 0x90;	// the function of these two bytes
	request[3] = 0x07;	// is not yet understood