usbvideo.c

基于S3CEB2410平台LINUX操作系统下 USB驱动源代码

		return;

	/* Unschedule all of the iso td's */
	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
		j = usb_unlink_urb(uvd->sbuf[i].urb);
		if (j < 0)
			err("%s: usb_unlink_urb() error %d.", proc, j);
	}
	if (uvd->debug > 1)
		info("%s: streaming=0", proc);
	uvd->streaming = 0;

	if (!uvd->remove_pending) {
		/* Invoke minidriver's magic to stop the camera */
		if (VALID_CALLBACK(uvd, videoStop))
			GET_CALLBACK(uvd, videoStop)(uvd);
		else 
			err("%s: videoStop not set" ,proc);

		/* Set packet size to 0 */
		j = usb_set_interface(uvd->dev, uvd->iface, uvd->ifaceAltInactive);
		if (j < 0) {
			err("%s: usb_set_interface() error %d.", proc, j);
			uvd->last_error = j;
		}
	}
}

/*
 * usbvideo_NewFrame()
 *
 * History:
 * 29-Mar-00 Added copying of previous frame into the current one.
 * 6-Aug-00  Added model 3 video sizes, removed redundant width, height.
 */
int usbvideo_NewFrame(uvd_t *uvd, int framenum)
{
	usbvideo_frame_t *frame;
	int n;

	if (uvd->debug > 1)
		info("usbvideo_NewFrame($%p,%d.)", uvd, framenum);

	/* If we're not grabbing a frame right now and the other frame is */
	/*  ready to be grabbed into, then use it instead */
	if (uvd->curframe != -1)
		return 0;

	/* If necessary we adjust picture settings between frames */
	if (!uvd->settingsAdjusted) {
		if (VALID_CALLBACK(uvd, adjustPicture))
			GET_CALLBACK(uvd, adjustPicture)(uvd);
		uvd->settingsAdjusted = 1;
	}

	n = (framenum - 1 + USBVIDEO_NUMFRAMES) % USBVIDEO_NUMFRAMES;
	if (uvd->frame[n].frameState == FrameState_Ready)
		framenum = n;

	frame = &uvd->frame[framenum];

	frame->frameState = FrameState_Grabbing;
	frame->scanstate = ScanState_Scanning;
	frame->seqRead_Length = 0;	/* Accumulated in xxx_parse_data() */
	frame->deinterlace = Deinterlace_None;
	frame->flags = 0; /* No flags yet, up to minidriver (or us) to set them */
	uvd->curframe = framenum;

	/*
	 * Normally we would want to copy previous frame into the current one
	 * before we even start filling it with data; this allows us to stop
	 * filling at any moment; top portion of the frame will be new and
	 * bottom portion will stay as it was in previous frame. If we don't
	 * do that then missing chunks of video stream will result in flickering
	 * portions of old data whatever it was before.
	 *
	 * If we choose not to copy previous frame (to, for example, save few
	 * bus cycles - the frame can be pretty large!) then we have an option
	 * to clear the frame before using. If we experience losses in this
	 * mode then missing picture will be black (no flickering).
	 *
	 * Finally, if user chooses not to clean the current frame before
	 * filling it with data then the old data will be visible if we fail
	 * to refill entire frame with new data.
	 */
	if (!(uvd->flags & FLAGS_SEPARATE_FRAMES)) {
		/* This copies previous frame into this one to mask losses */
		memmove(frame->data, uvd->frame[1-framenum].data, uvd->max_frame_size);
	} else {
		if (uvd->flags & FLAGS_CLEAN_FRAMES) {
			/* This provides a "clean" frame but slows things down */
			memset(frame->data, 0, uvd->max_frame_size);
		}
	}
	return 0;
}

/*
 * usbvideo_CollectRawData()
 *
 * This procedure can be used instead of 'processData' callback if you
 * only want to dump the raw data from the camera into the output
 * device (frame buffer). You can look at it with V4L client, but the
 * image will be unwatchable. The main purpose of this code and of the
 * mode FLAGS_NO_DECODING is debugging and capturing of datastreams from
 * new, unknown cameras. This procedure will be automatically invoked
 * instead of the specified callback handler when uvd->flags has bit
 * FLAGS_NO_DECODING set. Therefore, any regular build of any driver
 * based on usbvideo can use this feature at any time.
 */
void usbvideo_CollectRawData(uvd_t *uvd, usbvideo_frame_t *frame)
{
	int n;

	assert(uvd != NULL);
	assert(frame != NULL);

	/* Try to move data from queue into frame buffer */
	n = RingQueue_GetLength(&uvd->dp);
	if (n > 0) {
		int m;
		/* See how much space we have left */
		m = uvd->max_frame_size - frame->seqRead_Length;
		if (n > m)
			n = m;
		/* Now move that much data into frame buffer */
		RingQueue_Dequeue(
			&uvd->dp,
			frame->data + frame->seqRead_Length,
			m);
		frame->seqRead_Length += m;
	}
	/* See if we filled the frame */
	if (frame->seqRead_Length >= uvd->max_frame_size) {
		frame->frameState = FrameState_Done;
		uvd->curframe = -1;
		uvd->stats.frame_num++;
	}
}

int usbvideo_GetFrame(uvd_t *uvd, int frameNum)
{
	static const char proc[] = "usbvideo_GetFrame";
	usbvideo_frame_t *frame = &uvd->frame[frameNum];

	if (uvd->debug >= 2)
		info("%s($%p,%d.)", proc, uvd, frameNum);

	switch (frame->frameState) {
        case FrameState_Unused:
		if (uvd->debug >= 2)
			info("%s: FrameState_Unused", proc);
		return -EINVAL;
        case FrameState_Ready:
        case FrameState_Grabbing:
        case FrameState_Error:
        {
		int ntries, signalPending;
	redo:
		if (!CAMERA_IS_OPERATIONAL(uvd)) {
			if (uvd->debug >= 2)
				info("%s: Camera is not operational (1)", proc);
			return -EIO;
		}
		ntries = 0; 
		do {
			RingQueue_InterruptibleSleepOn(&uvd->dp);
			signalPending = signal_pending(current);
			if (!CAMERA_IS_OPERATIONAL(uvd)) {
				if (uvd->debug >= 2)
					info("%s: Camera is not operational (2)", proc);
				return -EIO;
			}
			assert(uvd->fbuf != NULL);
			if (signalPending) {
				if (uvd->debug >= 2)
					info("%s: Signal=$%08x", proc, signalPending);
				if (uvd->flags & FLAGS_RETRY_VIDIOCSYNC) {
					usbvideo_TestPattern(uvd, 1, 0);
					uvd->curframe = -1;
					uvd->stats.frame_num++;
					if (uvd->debug >= 2)
						info("%s: Forced test pattern screen", proc);
					return 0;
				} else {
					/* Standard answer: Interrupted! */
					if (uvd->debug >= 2)
						info("%s: Interrupted!", proc);
					return -EINTR;
				}
			} else {
				/* No signals - we just got new data in dp queue */
				if (uvd->flags & FLAGS_NO_DECODING)
					usbvideo_CollectRawData(uvd, frame);
				else if (VALID_CALLBACK(uvd, processData))
					GET_CALLBACK(uvd, processData)(uvd, frame);
				else 
					err("%s: processData not set", proc);
			}
		} while (frame->frameState == FrameState_Grabbing);
		if (uvd->debug >= 2) {
			info("%s: Grabbing done; state=%d. (%lu. bytes)",
			     proc, frame->frameState, frame->seqRead_Length);
		}
		if (frame->frameState == FrameState_Error) {
			int ret = usbvideo_NewFrame(uvd, frameNum);
			if (ret < 0) {
				err("%s: usbvideo_NewFrame() failed (%d.)", proc, ret);
				return ret;
			}
			goto redo;
		}
		/* Note that we fall through to meet our destiny below */
        }
        case FrameState_Done:
		/*
		 * Do all necessary postprocessing of data prepared in
		 * "interrupt" code and the collecting code above. The
		 * frame gets marked as FrameState_Done by queue parsing code.
		 * This status means that we collected enough data and
		 * most likely processed it as we went through. However
		 * the data may need postprocessing, such as deinterlacing
		 * or picture adjustments implemented in software (horror!)
		 *
		 * As soon as the frame becomes "final" it gets promoted to
		 * FrameState_Done_Hold status where it will remain until the
		 * caller consumed all the video data from the frame. Then
		 * the empty shell of ex-frame is thrown out for dogs to eat.
		 * But we, worried about pets, will recycle the frame!
		 */
		uvd->stats.frame_num++;
		if ((uvd->flags & FLAGS_NO_DECODING) == 0) {
			if (VALID_CALLBACK(uvd, postProcess))
				GET_CALLBACK(uvd, postProcess)(uvd, frame);
			if (frame->flags & USBVIDEO_FRAME_FLAG_SOFTWARE_CONTRAST)
				usbvideo_SoftwareContrastAdjustment(uvd, frame);
		}
		frame->frameState = FrameState_Done_Hold;
		if (uvd->debug >= 2)
			info("%s: Entered FrameState_Done_Hold state.", proc);
		return 0;

	case FrameState_Done_Hold:
		/*
		 * We stay in this state indefinitely until someone external,
		 * like ioctl() or read() call finishes digesting the frame
		 * data. Then it will mark the frame as FrameState_Unused and
		 * it will be released back into the wild to roam freely.
		 */
		if (uvd->debug >= 2)
			info("%s: FrameState_Done_Hold state.", proc);
		return 0;
	}

	/* Catch-all for other cases. We shall not be here. */
	err("%s: Invalid state %d.", proc, frame->frameState);
	frame->frameState = FrameState_Unused;
	return 0;
}

/*
 * usbvideo_DeinterlaceFrame()
 *
 * This procedure deinterlaces the given frame. Some cameras produce
 * only half of scanlines - sometimes only even lines, sometimes only
 * odd lines. The deinterlacing method is stored in frame->deinterlace
 * variable.
 *
 * Here we scan the frame vertically and replace missing scanlines with
 * average between surrounding ones - before and after. If we have no
 * line above then we just copy next line. Similarly, if we need to
 * create a last line then preceding line is used.
 */
void usbvideo_DeinterlaceFrame(uvd_t *uvd, usbvideo_frame_t *frame)
{
	if ((uvd == NULL) || (frame == NULL))
		return;

	if ((frame->deinterlace == Deinterlace_FillEvenLines) ||
	    (frame->deinterlace == Deinterlace_FillOddLines))
	{
		const int v4l_linesize = VIDEOSIZE_X(frame->request) * V4L_BYTES_PER_PIXEL;
		int i = (frame->deinterlace == Deinterlace_FillEvenLines) ? 0 : 1;

		for (; i < VIDEOSIZE_Y(frame->request); i += 2) {
			const unsigned char *fs1, *fs2;
			unsigned char *fd;
			int ip, in, j;	/* Previous and next lines */

			/*
			 * Need to average lines before and after 'i'.
			 * If we go out of bounds seeking those lines then
			 * we point back to existing line.
			 */
			ip = i - 1;	/* First, get rough numbers */
			in = i + 1;

			/* Now validate */
			if (ip < 0)
				ip = in;
			if (in >= VIDEOSIZE_Y(frame->request))
				in = ip;

			/* Sanity check */
			if ((ip < 0) || (in < 0) ||
			    (ip >= VIDEOSIZE_Y(frame->request)) ||
			    (in >= VIDEOSIZE_Y(frame->request)))
			{
				err("Error: ip=%d. in=%d. req.height=%ld.",
				    ip, in, VIDEOSIZE_Y(frame->request));
				break;
			}

			/* Now we need to average lines 'ip' and 'in' to produce line 'i' */
			fs1 = frame->data + (v4l_linesize * ip);
			fs2 = frame->data + (v4l_linesize * in);
			fd = frame->data + (v4l_linesize * i);

			/* Average lines around destination */
			for (j=0; j < v4l_linesize; j++) {
				fd[j] = (unsigned char)((((unsigned) fs1[j]) +
							 ((unsigned)fs2[j])) >> 1);
			}
		}
	}

	/* Optionally display statistics on the screen */
	if (uvd->flags & FLAGS_OVERLAY_STATS)
		usbvideo_OverlayStats(uvd, frame);
}

/*
 * usbvideo_SoftwareContrastAdjustment()
 *
 * This code adjusts the contrast of the frame, assuming RGB24 format.
 * As most software image processing, this job is CPU-intensive.
 * Get a camera that supports hardware adjustment!
 *
 * History:
 * 09-Feb-2001  Created.
 */
void usbvideo_SoftwareContrastAdjustment(uvd_t *uvd, usbvideo_frame_t *frame)
{
	static const char proc[] = "usbvideo_SoftwareContrastAdjustment";
	int i, j, v4l_linesize;
	signed long adj;
	const int ccm = 128; /* Color correction median - see below */

	if ((uvd == NULL) || (frame == NULL)) {
		err("%s: Illegal call.", proc);
		return;
	}
	adj = (uvd->vpic.contrast - 0x8000) >> 8; /* -128..+127 = -ccm..+(ccm-1)*/
	RESTRICT_TO_RANGE(adj, -ccm, ccm+1);
	if (adj == 0) {
		/* In rare case of no adjustment */
		return;
	}
	v4l_linesize = VIDEOSIZE_X(frame->request) * V4L_BYTES_PER_PIXEL;
	for (i=0; i < VIDEOSIZE_Y(frame->request); i++) {
		unsigned char *fd = frame->data + (v4l_linesize * i);
		for (j=0; j < v4l_linesize; j++) {
			signed long v = (signed long) fd[j];
			/* Magnify up to 2 times, reduce down to zero */
			v = 128 + ((ccm + adj) * (v - 128)) / ccm;
			RESTRICT_TO_RANGE(v, 0, 0xFF); /* Must flatten tails */
			fd[j] = (unsigned char) v;
		}
	}
}

/*
 * /proc interface
 *
 * We will be creating directories and entries under /proc/video using
 * external 'video_proc_entry' directory which is exported by videodev.o
 * module. Within that directory we will create $driver/ directory to
 * uniquely and uniformly refer to our specific $driver. Within that
 * directory we will finally create an entry that is named after the
 * video device node - video3, for example. The format of that file
 * is determined by callbacks that the minidriver may provide. If no
 * callbacks are provided (neither read nor write) then we don't create
 * the entry.
 *
 * Here is a sample directory entry: /proc/video/ibmcam/video3
 *
 * The "file" video3 (in example above) is readable and writeable, in
 * theory. If the minidriver provides callbacks to do reading and
 * writing then both those procedures are supported. However if the
 * driver leaves callbacks in default (NULL) state the default
 * read and write handlers are used. The default read handler reports
 * that the driver does not support /proc fs. The default write handler
 * returns error code on any write attempt.
 */

#if USES_PROC_FS

extern struct proc_dir_entry *video_proc_entry;

static void usbvideo_procfs_level1_create(usbvideo_t *ut)
{
	static const char proc[] = "usbvideo_procfs_level1_create";

	if (ut == NULL) {
		err("%s: ut == NULL", proc);
		return;
	}
	if (video_proc_entry == NULL) {
		err("%s: /proc/video/ doesn't exist.", proc);
		return;
	}
	ut->procfs_dEntry = create_proc_entry(ut->drvName, S_IFDIR, video_proc_entry);
	if (ut->procfs_dEntry != NULL) {
		if (ut->md_module != NULL)
			ut->procfs_dEntry->owner = ut->md_module;
	} else {
		err("%s: Unable to initialize /proc/video/%s", proc, ut->drvName);
	}
}

static void usbvideo_procfs_level1_destroy(usbvideo_t *ut)
{
	static const char proc[] = "usbvideo_procfs_level1_destroy";

	if (ut == NULL) {
		err("%s: ut == NULL", proc);
		return;
	}
	if (ut->procfs_dEntry != NULL) {
		remove_proc_entry(ut->drvName, video_proc_entry);
		ut->procfs_dEntry = NULL;
	}
}

static void usbvideo_procfs_level2_create(uvd_t *uvd)
{
	static const char proc[] = "usbvideo_procfs_level2_create";

	if (uvd == NULL) {
		err("%s: uvd == NULL", proc);
		return;
	}
	assert(uvd->handle != NULL);
	if (uvd->handle->procfs_dEntry == NULL) {
		err("%s: uvd->handle->procfs_dEntry == NULL", proc);
		return;
	}

	sprintf(uvd->videoName, "video%d", uvd->vdev.minor);
	uvd->procfs_vEntry = create_proc_entry(
		uvd->videoName,
		S_IFREG | S_IRUGO | S_IWUSR,
		uvd->handle->procfs_dEntry);
	if (uvd->procfs_vEntry != NULL) {
		uvd->procfs_vEntry->data = uvd;
		uvd->procfs_vEntry->read_proc = uvd->handle->cb.procfs_read;
		uvd->procfs_vEntry->write_proc = uvd->handle->cb.procfs_write;
	} else {
		err("%s: Failed to create entry \"%s\"", proc, uvd->videoName);
	}
}

static void usbvideo_procfs_level2_destroy(uvd_t *uvd)
{
	static const char proc[] = "usbvideo_procfs_level2_destroy";

	if (uvd == NULL) {
		err("%s: uvd == NULL", proc);
		return;
	}
	if (uvd->procfs_vEntry != NULL) {
		remove_proc_entry(uvd->videoName, uvd->procfs_vEntry);
		uvd->procfs_vEntry = NULL;
	}
}

static int usbvideo_default_procfs_read_proc(
	char *page, char **start, off_t off, int count,
	int *eof, void *data)
{
	char *out = page;
	int len;
	
	/* Stay under PAGE_SIZE or else