sn9c102_core.c

linux内核源码

	for (i = 0; i < len; i++) {
		size_t b;

		/* Read the variable part of the header */
		if (unlikely(cam->sof.bytesread >= sizeof(marker))) {
			cam->sof.header[cam->sof.bytesread] = *(m+i);
			if (++cam->sof.bytesread == soflen) {
				cam->sof.bytesread = 0;
				return mem + i;
			}
			continue;
		}

		/* Search for the SOF marker (fixed part) in the header */
		for (j = 0, b=cam->sof.bytesread; j+b < sizeof(marker); j++) {
			if (unlikely(i+j) == len)
				return NULL;
			if (*(m+i+j) == marker[cam->sof.bytesread]) {
				cam->sof.header[cam->sof.bytesread] = *(m+i+j);
				if (++cam->sof.bytesread == sizeof(marker)) {
					PDBGG("Bytes to analyze: %zd. SOF "
					      "starts at byte #%zd", len, i);
					i += j+1;
					break;
				}
			} else {
				cam->sof.bytesread = 0;
				break;
			}
		}
	}

	return NULL;
}


static void*
sn9c102_find_eof_header(struct sn9c102_device* cam, void* mem, size_t len)
{
	static const u8 eof_header[4][4] = {
		{0x00, 0x00, 0x00, 0x00},
		{0x40, 0x00, 0x00, 0x00},
		{0x80, 0x00, 0x00, 0x00},
		{0xc0, 0x00, 0x00, 0x00},
	};
	size_t i, j;

	/* The EOF header does not exist in compressed data */
	if (cam->sensor.pix_format.pixelformat == V4L2_PIX_FMT_SN9C10X ||
	    cam->sensor.pix_format.pixelformat == V4L2_PIX_FMT_JPEG)
		return NULL;

	/*
	   The EOF header might cross the packet boundary, but this is not a
	   problem, since the end of a frame is determined by checking its size
	   in the first place.
	*/
	for (i = 0; (len >= 4) && (i <= len - 4); i++)
		for (j = 0; j < ARRAY_SIZE(eof_header); j++)
			if (!memcmp(mem + i, eof_header[j], 4))
				return mem + i;

	return NULL;
}


static void
sn9c102_write_jpegheader(struct sn9c102_device* cam, struct sn9c102_frame_t* f)
{
	static const u8 jpeg_header[589] = {
		0xff, 0xd8, 0xff, 0xdb, 0x00, 0x84, 0x00, 0x06, 0x04, 0x05,
		0x06, 0x05, 0x04, 0x06, 0x06, 0x05, 0x06, 0x07, 0x07, 0x06,
		0x08, 0x0a, 0x10, 0x0a, 0x0a, 0x09, 0x09, 0x0a, 0x14, 0x0e,
		0x0f, 0x0c, 0x10, 0x17, 0x14, 0x18, 0x18, 0x17, 0x14, 0x16,
		0x16, 0x1a, 0x1d, 0x25, 0x1f, 0x1a, 0x1b, 0x23, 0x1c, 0x16,
		0x16, 0x20, 0x2c, 0x20, 0x23, 0x26, 0x27, 0x29, 0x2a, 0x29,
		0x19, 0x1f, 0x2d, 0x30, 0x2d, 0x28, 0x30, 0x25, 0x28, 0x29,
		0x28, 0x01, 0x07, 0x07, 0x07, 0x0a, 0x08, 0x0a, 0x13, 0x0a,
		0x0a, 0x13, 0x28, 0x1a, 0x16, 0x1a, 0x28, 0x28, 0x28, 0x28,
		0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
		0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
		0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
		0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
		0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0xff, 0xc4, 0x01, 0xa2,
		0x00, 0x00, 0x01, 0x05, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02,
		0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x01,
		0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
		0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03,
		0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x10, 0x00,
		0x02, 0x01, 0x03, 0x03, 0x02, 0x04, 0x03, 0x05, 0x05, 0x04,
		0x04, 0x00, 0x00, 0x01, 0x7d, 0x01, 0x02, 0x03, 0x00, 0x04,
		0x11, 0x05, 0x12, 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61,
		0x07, 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08, 0x23,
		0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0, 0x24, 0x33, 0x62,
		0x72, 0x82, 0x09, 0x0a, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x25,
		0x26, 0x27, 0x28, 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38,
		0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a,
		0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x63, 0x64,
		0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76,
		0x77, 0x78, 0x79, 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88,
		0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99,
		0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa,
		0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2,
		0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3,
		0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2, 0xe3,
		0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xf1, 0xf2, 0xf3,
		0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0x11, 0x00, 0x02,
		0x01, 0x02, 0x04, 0x04, 0x03, 0x04, 0x07, 0x05, 0x04, 0x04,
		0x00, 0x01, 0x02, 0x77, 0x00, 0x01, 0x02, 0x03, 0x11, 0x04,
		0x05, 0x21, 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
		0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, 0xa1, 0xb1,
		0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0, 0x15, 0x62, 0x72, 0xd1,
		0x0a, 0x16, 0x24, 0x34, 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19,
		0x1a, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
		0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a,
		0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x63, 0x64,
		0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76,
		0x77, 0x78, 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
		0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
		0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9,
		0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba,
		0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
		0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe2, 0xe3,
		0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xf2, 0xf3, 0xf4,
		0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xff, 0xc0, 0x00, 0x11,
		0x08, 0x01, 0xe0, 0x02, 0x80, 0x03, 0x01, 0x21, 0x00, 0x02,
		0x11, 0x01, 0x03, 0x11, 0x01, 0xff, 0xda, 0x00, 0x0c, 0x03,
		0x01, 0x00, 0x02, 0x11, 0x03, 0x11, 0x00, 0x3f, 0x00
	};
	u8 *pos = f->bufmem;

	memcpy(pos, jpeg_header, sizeof(jpeg_header));
	*(pos + 6) = 0x00;
	*(pos + 7 + 64) = 0x01;
	if (cam->compression.quality == 0) {
		memcpy(pos + 7, SN9C102_Y_QTABLE0, 64);
		memcpy(pos + 8 + 64, SN9C102_UV_QTABLE0, 64);
	} else if (cam->compression.quality == 1) {
		memcpy(pos + 7, SN9C102_Y_QTABLE1, 64);
		memcpy(pos + 8 + 64, SN9C102_UV_QTABLE1, 64);
	}
	*(pos + 564) = cam->sensor.pix_format.width & 0xFF;
	*(pos + 563) = (cam->sensor.pix_format.width >> 8) & 0xFF;
	*(pos + 562) = cam->sensor.pix_format.height & 0xFF;
	*(pos + 561) = (cam->sensor.pix_format.height >> 8) & 0xFF;
	*(pos + 567) = 0x21;

	f->buf.bytesused += sizeof(jpeg_header);
}


static void sn9c102_urb_complete(struct urb *urb)
{
	struct sn9c102_device* cam = urb->context;
	struct sn9c102_frame_t** f;
	size_t imagesize, soflen;
	u8 i;
	int err = 0;

	if (urb->status == -ENOENT)
		return;

	f = &cam->frame_current;

	if (cam->stream == STREAM_INTERRUPT) {
		cam->stream = STREAM_OFF;
		if ((*f))
			(*f)->state = F_QUEUED;
		cam->sof.bytesread = 0;
		DBG(3, "Stream interrupted by application");
		wake_up(&cam->wait_stream);
	}

	if (cam->state & DEV_DISCONNECTED)
		return;

	if (cam->state & DEV_MISCONFIGURED) {
		wake_up_interruptible(&cam->wait_frame);
		return;
	}

	if (cam->stream == STREAM_OFF || list_empty(&cam->inqueue))
		goto resubmit_urb;

	if (!(*f))
		(*f) = list_entry(cam->inqueue.next, struct sn9c102_frame_t,
				  frame);

	imagesize = (cam->sensor.pix_format.width *
		     cam->sensor.pix_format.height *
		     cam->sensor.pix_format.priv) / 8;
	if (cam->sensor.pix_format.pixelformat == V4L2_PIX_FMT_JPEG)
		imagesize += 589; /* length of jpeg header */
	soflen = sn9c102_sof_length(cam);

	for (i = 0; i < urb->number_of_packets; i++) {
		unsigned int img, len, status;
		void *pos, *sof, *eof;

		len = urb->iso_frame_desc[i].actual_length;
		status = urb->iso_frame_desc[i].status;
		pos = urb->iso_frame_desc[i].offset + urb->transfer_buffer;

		if (status) {
			DBG(3, "Error in isochronous frame");
			(*f)->state = F_ERROR;
			cam->sof.bytesread = 0;
			continue;
		}

		PDBGG("Isochrnous frame: length %u, #%u i", len, i);

redo:
		sof = sn9c102_find_sof_header(cam, pos, len);
		if (likely(!sof)) {
			eof = sn9c102_find_eof_header(cam, pos, len);
			if ((*f)->state == F_GRABBING) {
end_of_frame:
				img = len;

				if (eof)
					img = (eof > pos) ? eof - pos - 1 : 0;

				if ((*f)->buf.bytesused + img > imagesize) {
					u32 b;
					b = (*f)->buf.bytesused + img -
					    imagesize;
					img = imagesize - (*f)->buf.bytesused;
					PDBGG("Expected EOF not found: video "
					      "frame cut");
					if (eof)
						DBG(3, "Exceeded limit: +%u "
						       "bytes", (unsigned)(b));
				}

				memcpy((*f)->bufmem + (*f)->buf.bytesused, pos,
				       img);

				if ((*f)->buf.bytesused == 0)
					do_gettimeofday(&(*f)->buf.timestamp);

				(*f)->buf.bytesused += img;

				if ((*f)->buf.bytesused == imagesize ||
				    ((cam->sensor.pix_format.pixelformat ==
				      V4L2_PIX_FMT_SN9C10X ||
				      cam->sensor.pix_format.pixelformat ==
				      V4L2_PIX_FMT_JPEG) && eof)) {
					u32 b;

					b = (*f)->buf.bytesused;
					(*f)->state = F_DONE;
					(*f)->buf.sequence= ++cam->frame_count;

					spin_lock(&cam->queue_lock);
					list_move_tail(&(*f)->frame,
						       &cam->outqueue);
					if (!list_empty(&cam->inqueue))
						(*f) = list_entry(
							cam->inqueue.next,
							struct sn9c102_frame_t,
							frame );
					else
						(*f) = NULL;
					spin_unlock(&cam->queue_lock);

					memcpy(cam->sysfs.frame_header,
					       cam->sof.header, soflen);

					DBG(3, "Video frame captured: %lu "
					       "bytes", (unsigned long)(b));

					if (!(*f))
						goto resubmit_urb;

				} else if (eof) {
					(*f)->state = F_ERROR;
					DBG(3, "Not expected EOF after %lu "
					       "bytes of image data",
					    (unsigned long)
					    ((*f)->buf.bytesused));
				}

				if (sof) /* (1) */
					goto start_of_frame;

			} else if (eof) {
				DBG(3, "EOF without SOF");
				continue;

			} else {
				PDBGG("Ignoring pointless isochronous frame");
				continue;
			}

		} else if ((*f)->state == F_QUEUED || (*f)->state == F_ERROR) {
start_of_frame:
			(*f)->state = F_GRABBING;
			(*f)->buf.bytesused = 0;
			len -= (sof - pos);
			pos = sof;
			if (cam->sensor.pix_format.pixelformat ==
			    V4L2_PIX_FMT_JPEG)
				sn9c102_write_jpegheader(cam, (*f));
			DBG(3, "SOF detected: new video frame");
			if (len)
				goto redo;

		} else if ((*f)->state == F_GRABBING) {
			eof = sn9c102_find_eof_header(cam, pos, len);
			if (eof && eof < sof)
				goto end_of_frame; /* (1) */
			else {
				if (cam->sensor.pix_format.pixelformat ==
				    V4L2_PIX_FMT_SN9C10X ||
				    cam->sensor.pix_format.pixelformat ==
				    V4L2_PIX_FMT_JPEG) {
					if (sof - pos >= soflen) {
						eof = sof - soflen;
					} else { /* remove header */
						eof = pos;
						(*f)->buf.bytesused -=
							(soflen - (sof - pos));
					}
					goto end_of_frame;
				} else {
					DBG(3, "SOF before expected EOF after "
					       "%lu bytes of image data",
					    (unsigned long)
					    ((*f)->buf.bytesused));
					goto start_of_frame;
				}
			}
		}
	}

resubmit_urb:
	urb->dev = cam->usbdev;
	err = usb_submit_urb(urb, GFP_ATOMIC);
	if (err < 0 && err != -EPERM) {
		cam->state |= DEV_MISCONFIGURED;
		DBG(1, "usb_submit_urb() failed");
	}

	wake_up_interruptible(&cam->wait_frame);
}


static int sn9c102_start_transfer(struct sn9c102_device* cam)
{
	struct usb_device *udev = cam->usbdev;
	struct urb* urb;
	struct usb_host_interface* altsetting = usb_altnum_to_altsetting(
						    usb_ifnum_to_if(udev, 0),
						    SN9C102_ALTERNATE_SETTING);
	const unsigned int psz = le16_to_cpu(altsetting->
					     endpoint[0].desc.wMaxPacketSize);
	s8 i, j;
	int err = 0;

	for (i = 0; i < SN9C102_URBS; i++) {
		cam->transfer_buffer[i] = kzalloc(SN9C102_ISO_PACKETS * psz,
						  GFP_KERNEL);
		if (!cam->transfer_buffer[i]) {
			err = -ENOMEM;
			DBG(1, "Not enough memory");
			goto free_buffers;
		}
	}

	for (i = 0; i < SN9C102_URBS; i++) {
		urb = usb_alloc_urb(SN9C102_ISO_PACKETS, GFP_KERNEL);
		cam->urb[i] = urb;
		if (!urb) {
			err = -ENOMEM;
			DBG(1, "usb_alloc_urb() failed");
			goto free_urbs;
		}
		urb->dev = udev;
		urb->context = cam;
		urb->pipe = usb_rcvisocpipe(udev, 1);
		urb->transfer_flags = URB_ISO_ASAP;
		urb->number_of_packets = SN9C102_ISO_PACKETS;
		urb->complete = sn9c102_urb_complete;
		urb->transfer_buffer = cam->transfer_buffer[i];
		urb->transfer_buffer_length = psz * SN9C102_ISO_PACKETS;
		urb->interval = 1;
		for (j = 0; j < SN9C102_ISO_PACKETS; j++) {
			urb->iso_frame_desc[j].offset = psz * j;
			urb->iso_frame_desc[j].length = psz;
		}
	}

	/* Enable video */
	if (!(cam->reg[0x01] & 0x04)) {
		err = sn9c102_write_reg(cam, cam->reg[0x01] | 0x04, 0x01);
		if (err) {
			err = -EIO;
			DBG(1, "I/O hardware error");
			goto free_urbs;
		}
	}

	err = usb_set_interface(udev, 0, SN9C102_ALTERNATE_SETTING);
	if (err) {
		DBG(1, "usb_set_interface() failed");
		goto free_urbs;
	}

	cam->frame_current = NULL;
	cam->sof.bytesread = 0;

	for (i = 0; i < SN9C102_URBS; i++) {
		err = usb_submit_urb(cam->urb[i], GFP_KERNEL);
		if (err) {
			for (j = i-1; j >= 0; j--)
				usb_kill_urb(cam->urb[j]);
			DBG(1, "usb_submit_urb() failed, error %d", err);
			goto free_urbs;
		}
	}

	return 0;

free_urbs:
	for (i = 0; (i < SN9C102_URBS) && cam->urb[i]; i++)
		usb_free_urb(cam->urb[i]);

free_buffers:
	for (i = 0; (i < SN9C102_URBS) && cam->transfer_buffer[i]; i++)
		kfree(cam->transfer_buffer[i]);

	return err;
}


static int sn9c102_stop_transfer(struct sn9c102_device* cam)
{
	struct usb_device *udev = cam->usbdev;
	s8 i;
	int err = 0;

	if (cam->state & DEV_DISCONNECTED)
		return 0;

	for (i = SN9C102_URBS-1; i >= 0; i--) {
		usb_kill_urb(cam->urb[i]);
		usb_free_urb(cam->urb[i]);
		kfree(cam->transfer_buffer[i]);
	}

	err = usb_set_interface(udev, 0, 0); /* 0 Mb/s */
	if (err)
		DBG(3, "usb_set_interface() failed");

	return err;
}


static int sn9c102_stream_interrupt(struct sn9c102_device* cam)
{
	long timeout;

	cam->stream = STREAM_INTERRUPT;
	timeout = wait_event_timeout(cam->wait_stream,
				     (cam->stream == STREAM_OFF) ||
				     (cam->state & DEV_DISCONNECTED),
				     SN9C102_URB_TIMEOUT);
	if (cam->state & DEV_DISCONNECTED)
		return -ENODEV;
	else if (cam->stream != STREAM_OFF) {
		cam->state |= DEV_MISCONFIGURED;
		DBG(1, "URB timeout reached. The camera is misconfigured. "
		       "To use it, close and open /dev/video%d again.",
		    cam->v4ldev->minor);
		return -EIO;
	}

	return 0;
}

/*****************************************************************************/

#ifdef CONFIG_VIDEO_ADV_DEBUG
static u16 sn9c102_strtou16(const char* buff, size_t len, ssize_t* count)
{
	char str[7];
	char* endp;
	unsigned long val;

	if (len < 6) {
		strncpy(str, buff, len);
		str[len] = '\0';
	} else {
		strncpy(str, buff, 6);
		str[6] = '\0';
	}

	val = simple_strtoul(str, &endp, 0);

	*count = 0;
	if (val <= 0xffff)
		*count = (ssize_t)(endp - str);
	if ((*count) && (len == *count+1) && (buff[*count] == '\n'))
		*count += 1;

	return (u16)val;
}

/*
   NOTE 1: being inside one of the following methods implies that the v4l
	   device exists for sure (see kobjects and reference counters)