usbvideo.c

h内核

 * usbvideo_v4l_open()
 *
 * This is part of Video 4 Linux API. The driver can be opened by one
 * client only (checks internal counter 'uvdser'). The procedure
 * then allocates buffers needed for video processing.
 *
 * History:
 * 22-Jan-2000 Rewrote, moved scratch buffer allocation here. Now the
 *             camera is also initialized here (once per connect), at
 *             expense of V4L client (it waits on open() call).
 * 27-Jan-2000 Used USBVIDEO_NUMSBUF as number of URB buffers.
 * 24-May-2000 Corrected to prevent race condition (MOD_xxx_USE_COUNT).
 */
static int usbvideo_v4l_open(struct inode *inode, struct file *file)
{
	struct video_device *dev = video_devdata(file);
	struct uvd *uvd = (struct uvd *) dev;
	const int sb_size = FRAMES_PER_DESC * uvd->iso_packet_len;
	int i, errCode = 0;

	if (uvd->debug > 1)
		info("%s($%p)", __FUNCTION__, dev);

	usbvideo_ClientIncModCount(uvd);
	down(&uvd->lock);

	if (uvd->user) {
		err("%s: Someone tried to open an already opened device!", __FUNCTION__);
		errCode = -EBUSY;
	} else {
		/* Clear statistics */
		memset(&uvd->stats, 0, sizeof(uvd->stats));

		/* Clean pointers so we know if we allocated something */
		for (i=0; i < USBVIDEO_NUMSBUF; i++)
			uvd->sbuf[i].data = NULL;

		/* Allocate memory for the frame buffers */
		uvd->fbuf_size = USBVIDEO_NUMFRAMES * uvd->max_frame_size;
		uvd->fbuf = usbvideo_rvmalloc(uvd->fbuf_size);
		RingQueue_Allocate(&uvd->dp, RING_QUEUE_SIZE);
		if ((uvd->fbuf == NULL) ||
		    (!RingQueue_IsAllocated(&uvd->dp))) {
			err("%s: Failed to allocate fbuf or dp", __FUNCTION__);
			errCode = -ENOMEM;
		} else {
			/* Allocate all buffers */
			for (i=0; i < USBVIDEO_NUMFRAMES; i++) {
				uvd->frame[i].frameState = FrameState_Unused;
				uvd->frame[i].data = uvd->fbuf + i*(uvd->max_frame_size);
				/*
				 * Set default sizes in case IOCTL (VIDIOCMCAPTURE)
				 * is not used (using read() instead).
				 */
				uvd->frame[i].canvas = uvd->canvas;
				uvd->frame[i].seqRead_Index = 0;
			}
			for (i=0; i < USBVIDEO_NUMSBUF; i++) {
				uvd->sbuf[i].data = kmalloc(sb_size, GFP_KERNEL);
				if (uvd->sbuf[i].data == NULL) {
					errCode = -ENOMEM;
					break;
				}
			}
		}
		if (errCode != 0) {
			/* Have to free all that memory */
			if (uvd->fbuf != NULL) {
				usbvideo_rvfree(uvd->fbuf, uvd->fbuf_size);
				uvd->fbuf = NULL;
			}
			RingQueue_Free(&uvd->dp);
			for (i=0; i < USBVIDEO_NUMSBUF; i++) {
				if (uvd->sbuf[i].data != NULL) {
					kfree (uvd->sbuf[i].data);
					uvd->sbuf[i].data = NULL;
				}
			}
		}
	}

	/* If so far no errors then we shall start the camera */
	if (errCode == 0) {
		/* Start data pump if we have valid endpoint */
		if (uvd->video_endp != 0)
			errCode = GET_CALLBACK(uvd, startDataPump)(uvd);
		if (errCode == 0) {
			if (VALID_CALLBACK(uvd, setupOnOpen)) {
				if (uvd->debug > 1)
					info("%s: setupOnOpen callback", __FUNCTION__);
				errCode = GET_CALLBACK(uvd, setupOnOpen)(uvd);
				if (errCode < 0) {
					err("%s: setupOnOpen callback failed (%d.).",
					    __FUNCTION__, errCode);
				} else if (uvd->debug > 1) {
					info("%s: setupOnOpen callback successful", __FUNCTION__);
				}
			}
			if (errCode == 0) {
				uvd->settingsAdjusted = 0;
				if (uvd->debug > 1)
					info("%s: Open succeeded.", __FUNCTION__);
				uvd->user++;
				file->private_data = uvd;
			}
		}
	}
	up(&uvd->lock);
	if (errCode != 0)
		usbvideo_ClientDecModCount(uvd);
	if (uvd->debug > 0)
		info("%s: Returning %d.", __FUNCTION__, errCode);
	return errCode;
}

/*
 * usbvideo_v4l_close()
 *
 * This is part of Video 4 Linux API. The procedure
 * stops streaming and deallocates all buffers that were earlier
 * allocated in usbvideo_v4l_open().
 *
 * History:
 * 22-Jan-2000 Moved scratch buffer deallocation here.
 * 27-Jan-2000 Used USBVIDEO_NUMSBUF as number of URB buffers.
 * 24-May-2000 Moved MOD_DEC_USE_COUNT outside of code that can sleep.
 */
static int usbvideo_v4l_close(struct inode *inode, struct file *file)
{
	struct video_device *dev = file->private_data;
	struct uvd *uvd = (struct uvd *) dev;
	int i;

	if (uvd->debug > 1)
		info("%s($%p)", __FUNCTION__, dev);

	down(&uvd->lock);
	GET_CALLBACK(uvd, stopDataPump)(uvd);
	usbvideo_rvfree(uvd->fbuf, uvd->fbuf_size);
	uvd->fbuf = NULL;
	RingQueue_Free(&uvd->dp);

	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
		kfree(uvd->sbuf[i].data);
		uvd->sbuf[i].data = NULL;
	}

#if USBVIDEO_REPORT_STATS
	usbvideo_ReportStatistics(uvd);
#endif    

	uvd->user--;
	if (uvd->remove_pending) {
		if (uvd->debug > 0)
			info("usbvideo_v4l_close: Final disconnect.");
		usbvideo_CameraRelease(uvd);
	}
	up(&uvd->lock);
	usbvideo_ClientDecModCount(uvd);

	if (uvd->debug > 1)
		info("%s: Completed.", __FUNCTION__);
	file->private_data = NULL;
	return 0;
}

/*
 * usbvideo_v4l_ioctl()
 *
 * This is part of Video 4 Linux API. The procedure handles ioctl() calls.
 *
 * History:
 * 22-Jan-2000 Corrected VIDIOCSPICT to reject unsupported settings.
 */
static int usbvideo_v4l_do_ioctl(struct inode *inode, struct file *file,
				 unsigned int cmd, void *arg)
{
	struct uvd *uvd = file->private_data;

	if (!CAMERA_IS_OPERATIONAL(uvd))
		return -EIO;

	switch (cmd) {
		case VIDIOCGCAP:
		{
			struct video_capability *b = arg;
			*b = uvd->vcap;
			return 0;
		}
		case VIDIOCGCHAN:
		{
			struct video_channel *v = arg;
			*v = uvd->vchan;
			return 0;
		}
		case VIDIOCSCHAN:
		{	
			struct video_channel *v = arg;
			if (v->channel != 0)
				return -EINVAL;
			return 0;
		}
		case VIDIOCGPICT:
		{
			struct video_picture *pic = arg;
			*pic = uvd->vpic;
			return 0;
		}
		case VIDIOCSPICT:
		{
			struct video_picture *pic = arg;
			/*
			 * Use temporary 'video_picture' structure to preserve our
			 * own settings (such as color depth, palette) that we
			 * aren't allowing everyone (V4L client) to change.
			 */
			uvd->vpic.brightness = pic->brightness;
			uvd->vpic.hue = pic->hue;
			uvd->vpic.colour = pic->colour;
			uvd->vpic.contrast = pic->contrast;
			uvd->settingsAdjusted = 0;	/* Will force new settings */
			return 0;
		}
		case VIDIOCSWIN:
		{
			struct video_window *vw = arg;

			if(VALID_CALLBACK(uvd, setVideoMode)) {
				return GET_CALLBACK(uvd, setVideoMode)(uvd, vw);
			}

			if (vw->flags)
				return -EINVAL;
			if (vw->clipcount)
				return -EINVAL;
			if (vw->width != VIDEOSIZE_X(uvd->canvas))
				return -EINVAL;
			if (vw->height != VIDEOSIZE_Y(uvd->canvas))
				return -EINVAL;

			return 0;
		}
		case VIDIOCGWIN:
		{
			struct video_window *vw = arg;

			vw->x = 0;
			vw->y = 0;
			vw->width = VIDEOSIZE_X(uvd->videosize);
			vw->height = VIDEOSIZE_Y(uvd->videosize);
			vw->chromakey = 0;
			if (VALID_CALLBACK(uvd, getFPS))
				vw->flags = GET_CALLBACK(uvd, getFPS)(uvd);
			else 
				vw->flags = 10; /* FIXME: do better! */
			return 0;
		}
		case VIDIOCGMBUF:
		{
			struct video_mbuf *vm = arg;
			int i;

			memset(vm, 0, sizeof(*vm));
			vm->size = uvd->max_frame_size * USBVIDEO_NUMFRAMES;
			vm->frames = USBVIDEO_NUMFRAMES;
			for(i = 0; i < USBVIDEO_NUMFRAMES; i++) 
			  vm->offsets[i] = i * uvd->max_frame_size;

			return 0;
		}
		case VIDIOCMCAPTURE:
		{
			struct video_mmap *vm = arg;

			if (uvd->debug >= 1) {
				info("VIDIOCMCAPTURE: frame=%d. size=%dx%d, format=%d.",
				     vm->frame, vm->width, vm->height, vm->format);
			}
			/*
			 * Check if the requested size is supported. If the requestor
			 * requests too big a frame then we may be tricked into accessing
			 * outside of own preallocated frame buffer (in uvd->frame).
			 * This will cause oops or a security hole. Theoretically, we
			 * could only clamp the size down to acceptable bounds, but then
			 * we'd need to figure out how to insert our smaller buffer into
			 * larger caller's buffer... this is not an easy question. So we
			 * here just flatly reject too large requests, assuming that the
			 * caller will resubmit with smaller size. Callers should know
			 * what size we support (returned by VIDIOCGCAP). However vidcat,
			 * for one, does not care and allows to ask for any size.
			 */
			if ((vm->width > VIDEOSIZE_X(uvd->canvas)) ||
			    (vm->height > VIDEOSIZE_Y(uvd->canvas))) {
				if (uvd->debug > 0) {
					info("VIDIOCMCAPTURE: Size=%dx%d too large; "
					     "allowed only up to %ldx%ld", vm->width, vm->height,
					     VIDEOSIZE_X(uvd->canvas), VIDEOSIZE_Y(uvd->canvas));
				}
				return -EINVAL;
			}
			/* Check if the palette is supported */
			if (((1L << vm->format) & uvd->paletteBits) == 0) {
				if (uvd->debug > 0) {
					info("VIDIOCMCAPTURE: format=%d. not supported"
					     " (paletteBits=$%08lx)",
					     vm->format, uvd->paletteBits);
				}
				return -EINVAL;
			}
			if ((vm->frame < 0) || (vm->frame >= USBVIDEO_NUMFRAMES)) {
				err("VIDIOCMCAPTURE: vm.frame=%d. !E [0-%d]", vm->frame, USBVIDEO_NUMFRAMES-1);
				return -EINVAL;
			}
			if (uvd->frame[vm->frame].frameState == FrameState_Grabbing) {
				/* Not an error - can happen */
			}
			uvd->frame[vm->frame].request = VIDEOSIZE(vm->width, vm->height);
			uvd->frame[vm->frame].palette = vm->format;

			/* Mark it as ready */
			uvd->frame[vm->frame].frameState = FrameState_Ready;

			return usbvideo_NewFrame(uvd, vm->frame);
		}
		case VIDIOCSYNC:
		{
			int *frameNum = arg;
			int ret;

			if (*frameNum < 0 || *frameNum >= USBVIDEO_NUMFRAMES)
				return -EINVAL;
				
			if (uvd->debug >= 1)
				info("VIDIOCSYNC: syncing to frame %d.", *frameNum);
			if (uvd->flags & FLAGS_NO_DECODING)
				ret = usbvideo_GetFrame(uvd, *frameNum);
			else if (VALID_CALLBACK(uvd, getFrame)) {
				ret = GET_CALLBACK(uvd, getFrame)(uvd, *frameNum);
				if ((ret < 0) && (uvd->debug >= 1)) {
					err("VIDIOCSYNC: getFrame() returned %d.", ret);
				}
			} else {
				err("VIDIOCSYNC: getFrame is not set");
				ret = -EFAULT;
			}

			/*
			 * The frame is in FrameState_Done_Hold state. Release it
			 * right now because its data is already mapped into
			 * the user space and it's up to the application to
			 * make use of it until it asks for another frame.
			 */
			uvd->frame[*frameNum].frameState = FrameState_Unused;
			return ret;
		}
		case VIDIOCGFBUF:
		{
			struct video_buffer *vb = arg;

			memset(vb, 0, sizeof(*vb));
 			return 0;
 		}
		case VIDIOCKEY:
			return 0;

		case VIDIOCCAPTURE:
			return -EINVAL;

		case VIDIOCSFBUF:

		case VIDIOCGTUNER:
		case VIDIOCSTUNER:

		case VIDIOCGFREQ:
		case VIDIOCSFREQ:

		case VIDIOCGAUDIO:
		case VIDIOCSAUDIO:
			return -EINVAL;

		default:
			return -ENOIOCTLCMD;
	}
	return 0;
}

static int usbvideo_v4l_ioctl(struct inode *inode, struct file *file,
		       unsigned int cmd, unsigned long arg)
{
	return video_usercopy(inode, file, cmd, arg, usbvideo_v4l_do_ioctl);
}

/*
 * usbvideo_v4l_read()
 *
 * This is mostly boring stuff. We simply ask for a frame and when it
 * arrives copy all the video data from it into user space. There is
 * no obvious need to override this method.
 *
 * History:
 * 20-Oct-2000 Created.
 * 01-Nov-2000 Added mutex (uvd->lock).
 */
static ssize_t usbvideo_v4l_read(struct file *file, char __user *buf,
		      size_t count, loff_t *ppos)
{
	struct uvd *uvd = file->private_data;
	int noblock = file->f_flags & O_NONBLOCK;
	int frmx = -1, i;
	struct usbvideo_frame *frame;

	if (!CAMERA_IS_OPERATIONAL(uvd) || (buf == NULL))
		return -EFAULT;

	if (uvd->debug >= 1)
		info("%s: %Zd. bytes, noblock=%d.", __FUNCTION__, count, noblock);

	down(&uvd->lock);	

	/* See if a frame is completed, then use it. */
	for(i = 0; i < USBVIDEO_NUMFRAMES; i++) {
		if ((uvd->frame[i].frameState == FrameState_Done) ||
		    (uvd->frame[i].frameState == FrameState_Done_Hold) ||
		    (uvd->frame[i].frameState == FrameState_Error)) {
			frmx = i;
			break;
		}
	}

	/* FIXME: If we don't start a frame here then who ever does? */
	if (noblock && (frmx == -1)) {
		count = -EAGAIN;
		goto read_done;
	}

	/*
	 * If no FrameState_Done, look for a FrameState_Grabbing state.
	 * See if a frame is in process (grabbing), then use it.
	 * We will need to wait until it becomes cooked, of course.
	 */
	if (frmx == -1) {
		for(i = 0; i < USBVIDEO_NUMFRAMES; i++) {
			if (uvd->frame[i].frameState == FrameState_Grabbing) {
				frmx = i;
				break;
			}
		}
	}

	/*
	 * If no frame is active, start one. We don't care which one
	 * it will be, so #0 is as good as any.
	 * In read access mode we don't have convenience of VIDIOCMCAPTURE
	 * to specify the requested palette (video format) on per-frame
	 * basis. This means that we have to return data in -some- format
	 * and just hope that the client knows what to do with it.
	 * The default format is configured in uvd->defaultPalette field
	 * as one of VIDEO_PALETTE_xxx values. We stuff it into the new
	 * frame and initiate the frame filling process.
	 */
	if (frmx == -1) {
		if (uvd->defaultPalette == 0) {
			err("%s: No default palette; don't know what to do!", __FUNCTION__);
			count = -EFAULT;
			goto read_done;
		}
		frmx = 0;
		/*
		 * We have no per-frame control over video size.
		 * Therefore we only can use whatever size was
		 * specified as default.
		 */
		uvd->frame[frmx].request = uvd->videosize;
		uvd->frame[frmx].palette = uvd->defaultPalette;
		uvd->frame[frmx].frameState = FrameState_Ready;
		usbvideo_NewFrame(uvd, frmx);
		/* Now frame 0 is supposed to start filling... */
	}

	/*
	 * Get a pointer to the active frame. It is either previously
	 * completed frame or frame in progress but not completed yet.
	 */
	frame = &uvd->frame[frmx];

	/*
	 * Sit back & wait until the frame gets filled and postprocessed.
	 * If we fail to get the picture [in time] then return the error.
	 * In this call we specify that we want the frame to be waited for,
	 * postprocessed and switched into FrameState_Done_Hold state. This
	 * state is used to hold the frame as "fully completed" between
	 * subsequent partial reads of the same frame.
	 */
	if (frame->frameState != FrameState_Done_Hold) {
		long rv = -EFAULT;
		if (uvd->flags & FLAGS_NO_DECODING)
			rv = usbvideo_GetFrame(uvd, frmx);
		else if (VALID_CALLBACK(uvd, getFrame))
			rv = GET_CALLBACK(uvd, getFrame)(uvd, frmx);
		else
			err("getFrame is not set");
		if ((rv != 0) || (frame->frameState != FrameState_Done_Hold)) {
			count = rv;
			goto read_done;
		}
	}

	/*
	 * Copy bytes to user space. We allow for partial reads, which
	 * means that the user application can request read less than
	 * the full frame size. It is up to the application to issue
	 * subsequent calls until entire frame is read.
	 *
	 * First things first, make sure we don't copy more than we
	 * have - even if the application wants more. That would be
	 * a big security embarassment!
	 */
	if ((count + frame->seqRead_Index) > frame->seqRead_Length)
		count = frame->seqRead_Length - frame->seqRead_Index;

	/*
	 * Copy requested amount of data to user space. We start
	 * copying from the position where we last left it, which
	 * will be zero for a new frame (not read before).
	 */
	if (copy_to_user(buf, frame->data + frame->seqRead_Index, count)) {
		count = -EFAULT;
		goto read_done;
	}

	/* Update last read position */
	frame->seqRead_Index += count;
	if (uvd->debug >= 1) {
		err("%s: {copy} count used=%Zd, new seqRead_Index=%ld",
			__FUNCTION__, count, frame->seqRead_Index);
	}

	/* Finally check if the frame is done with and "release" it */
	if (frame->seqRead_Index >= frame->seqRead_Length) {
		/* All data has been read */
		frame->seqRead_Index = 0;

		/* Mark it as available to be used again. */
		uvd->frame[frmx].frameState = FrameState_Unused;
		if (usbvideo_NewFrame(uvd, (frmx + 1) % USBVIDEO_NUMFRAMES)) {
			err("%s: usbvideo_NewFrame failed.", __FUNCTION__);
		}
	}
read_done: