vicam.c

linux内核源码

	/* guard against simultaneous accesses to the camera */
	struct mutex cam_lock;

	int is_initialized;
	u8 open_count;
	u8 bulkEndpoint;
	int needsDummyRead;
};

static int vicam_probe( struct usb_interface *intf, const struct usb_device_id *id);
static void vicam_disconnect(struct usb_interface *intf);
static void read_frame(struct vicam_camera *cam, int framenum);
static void vicam_decode_color(const u8 *, u8 *);

static int __send_control_msg(struct vicam_camera *cam,
			      u8 request,
			      u16 value,
			      u16 index,
			      unsigned char *cp,
			      u16 size)
{
	int status;

	/* cp must be memory that has been allocated by kmalloc */

	status = usb_control_msg(cam->udev,
				 usb_sndctrlpipe(cam->udev, 0),
				 request,
				 USB_DIR_OUT | USB_TYPE_VENDOR |
				 USB_RECIP_DEVICE, value, index,
				 cp, size, 1000);

	status = min(status, 0);

	if (status < 0) {
		printk(KERN_INFO "Failed sending control message, error %d.\n",
		       status);
	}

	return status;
}

static int send_control_msg(struct vicam_camera *cam,
			    u8 request,
			    u16 value,
			    u16 index,
			    unsigned char *cp,
			    u16 size)
{
	int status = -ENODEV;
	mutex_lock(&cam->cam_lock);
	if (cam->udev) {
		status = __send_control_msg(cam, request, value,
					    index, cp, size);
	}
	mutex_unlock(&cam->cam_lock);
	return status;
}
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");
		return -EINVAL;
	}

	/* 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");