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Commit 227b7c90 authored by Frank Schaefer's avatar Frank Schaefer Committed by Mauro Carvalho Chehab
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[media] em28xx: move the em2710/em2750/em28xx specific frame data processing... 


[media] em28xx: move the em2710/em2750/em28xx specific frame data processing code to a separate function

em28xx_urb_data_copy() actually consists of two parts:
USB urb processing (checks, data extraction) and frame data packet processing.
Move the latter to a separate function and call it from em28xx_urb_data_copy()
for each data packet.
The em25xx, em2760, em2765 (and likely em277x) chip variants are using a
different frame data format, for which support will be added later with
another function.
This reduces the size of em28xx_urb_data_copy() and makes the code much more
readable. While we're at it, clean up the code a bit (rename some variables to
something more meaningful, improve some comments etc.)

Signed-off-by: default avatarFrank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent e04c00d9

drivers/media/usb/em28xx/em28xx-video.c

+90 −80
Original line number Diff line number Diff line
@@ -379,15 +379,90 @@ finish_field_prepare_next(struct em28xx *dev, 
	return buf;

}



/* Processes and copies the URB data content (video and VBI data) */

static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb)

/*

 * Process data packet according to the em2710/em2750/em28xx frame data format

 */

static inline void process_frame_data_em28xx(struct em28xx *dev,

					     unsigned char *data_pkt,

					     unsigned int  data_len)

{

	struct em28xx_buffer    *buf, *vbi_buf;

	struct em28xx_buffer    *buf = dev->usb_ctl.vid_buf;

	struct em28xx_buffer    *vbi_buf = dev->usb_ctl.vbi_buf;

	struct em28xx_dmaqueue  *dma_q = &dev->vidq;

	struct em28xx_dmaqueue  *vbi_dma_q = &dev->vbiq;

	int xfer_bulk, num_packets, i, rc = 1;

	unsigned int actual_length, len = 0;

	unsigned char *p;



	/* capture type 0 = vbi start

	   capture type 1 = vbi in progress

	   capture type 2 = video start

	   capture type 3 = video in progress */

	if (data_len >= 4) {

		/* NOTE: Headers are always 4 bytes and

		 * never split across packets */

		if (data_pkt[0] == 0x88 && data_pkt[1] == 0x88 &&

		    data_pkt[2] == 0x88 && data_pkt[3] == 0x88) {

			/* Continuation */

			data_pkt += 4;

			data_len -= 4;

		} else if (data_pkt[0] == 0x33 && data_pkt[1] == 0x95) {

			/* Field start (VBI mode) */

			dev->capture_type = 0;

			dev->vbi_read = 0;

			em28xx_isocdbg("VBI START HEADER !!!\n");

			dev->top_field = !(data_pkt[2] & 1);

			data_pkt += 4;

			data_len -= 4;

		} else if (data_pkt[0] == 0x22 && data_pkt[1] == 0x5a) {

			/* Field start (VBI disabled) */

			dev->capture_type = 2;

			em28xx_isocdbg("VIDEO START HEADER !!!\n");

			dev->top_field = !(data_pkt[2] & 1);

			data_pkt += 4;

			data_len -= 4;

		}

	}

	/* NOTE: With bulk transfers, intermediate data packets

	 * have no continuation header */



	if (dev->capture_type == 0) {

		vbi_buf = finish_field_prepare_next(dev, vbi_buf, vbi_dma_q);

		dev->usb_ctl.vbi_buf = vbi_buf;

		dev->capture_type = 1;

	}



	if (dev->capture_type == 1) {

		int vbi_size = dev->vbi_width * dev->vbi_height;

		int vbi_data_len = ((dev->vbi_read + data_len) > vbi_size) ?

				   (vbi_size - dev->vbi_read) : data_len;



		/* Copy VBI data */

		if (vbi_buf != NULL)

			em28xx_copy_vbi(dev, vbi_buf, data_pkt, vbi_data_len);

		dev->vbi_read += vbi_data_len;



		if (vbi_data_len < data_len) {

			/* Continue with copying video data */

			dev->capture_type = 2;

			data_pkt += vbi_data_len;

			data_len -= vbi_data_len;

		}

	}



	if (dev->capture_type == 2) {

		buf = finish_field_prepare_next(dev, buf, dma_q);

		dev->usb_ctl.vid_buf = buf;

		dev->capture_type = 3;

	}



	if (dev->capture_type == 3 && buf != NULL && data_len > 0)

		em28xx_copy_video(dev, buf, data_pkt, data_len);

}



/* Processes and copies the URB data content (video and VBI data) */

static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb)

{

	int xfer_bulk, num_packets, i;

	unsigned char *usb_data_pkt;

	unsigned int usb_data_len;



	if (!dev)

		return 0;
@@ -400,9 +475,6 @@ static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb) 


	xfer_bulk = usb_pipebulk(urb->pipe);



	buf = dev->usb_ctl.vid_buf;

	vbi_buf = dev->usb_ctl.vbi_buf;



	if (xfer_bulk) /* bulk */

		num_packets = 1;

	else /* isoc */
@@ -410,9 +482,9 @@ static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb) 


	for (i = 0; i < num_packets; i++) {

		if (xfer_bulk) { /* bulk */

			actual_length = urb->actual_length;

			usb_data_len = urb->actual_length;



			p = urb->transfer_buffer;

			usb_data_pkt = urb->transfer_buffer;

		} else { /* isoc */

			if (urb->iso_frame_desc[i].status < 0) {

				print_err_status(dev, i,
@@ -421,87 +493,25 @@ static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb) 
					continue;

			}



			actual_length = urb->iso_frame_desc[i].actual_length;

			if (actual_length > dev->max_pkt_size) {

			usb_data_len = urb->iso_frame_desc[i].actual_length;

			if (usb_data_len > dev->max_pkt_size) {

				em28xx_isocdbg("packet bigger than packet size");

				continue;

			}



			p = urb->transfer_buffer +

			usb_data_pkt = urb->transfer_buffer +

				       urb->iso_frame_desc[i].offset;

		}



		if (actual_length == 0) {

		if (usb_data_len == 0) {

			/* NOTE: happens very often with isoc transfers */

			/* em28xx_usbdbg("packet %d is empty",i); - spammy */

			continue;

		}



		/* capture type 0 = vbi start

		   capture type 1 = vbi in progress

		   capture type 2 = video start

		   capture type 3 = video in progress */

		len = actual_length;

		if (len >= 4) {

			/* NOTE: headers are always 4 bytes and

			 * never split across packets */

			if (p[0] == 0x33 && p[1] == 0x95) {

				dev->capture_type = 0;

				dev->vbi_read = 0;

				em28xx_isocdbg("VBI START HEADER!!!\n");

				dev->top_field = !(p[2] & 1);

				p += 4;

				len -= 4;

			} else if (p[0] == 0x88 && p[1] == 0x88 &&

				   p[2] == 0x88 && p[3] == 0x88) {

				/* continuation */

				p += 4;

				len -= 4;

			} else if (p[0] == 0x22 && p[1] == 0x5a) {

				/* start video */

				dev->capture_type = 2;

				dev->top_field = !(p[2] & 1);

				p += 4;

				len -= 4;

			}

		}

		/* NOTE: with bulk transfers, intermediate data packets

		 * have no continuation header */



		if (dev->capture_type == 0) {

			vbi_buf = finish_field_prepare_next(dev, vbi_buf, vbi_dma_q);

			dev->usb_ctl.vbi_buf = vbi_buf;

			dev->capture_type = 1;

		process_frame_data_em28xx(dev, usb_data_pkt, usb_data_len);

	}



		if (dev->capture_type == 1) {

			int vbi_size = dev->vbi_width * dev->vbi_height;

			int vbi_data_len = ((dev->vbi_read + len) > vbi_size) ?

					   (vbi_size - dev->vbi_read) : len;



			/* Copy VBI data */

			if (vbi_buf != NULL)

				em28xx_copy_vbi(dev, vbi_buf, p, vbi_data_len);

			dev->vbi_read += vbi_data_len;



			if (vbi_data_len < len) {

				/* Continue with copying video data */

				dev->capture_type = 2;

				p += vbi_data_len;

				len -= vbi_data_len;

			}

		}



		if (dev->capture_type == 2) {

			buf = finish_field_prepare_next(dev, buf, dma_q);

			dev->usb_ctl.vid_buf = buf;

			dev->capture_type = 3;

		}



		if (buf != NULL && dev->capture_type == 3 && len > 0)

			em28xx_copy_video(dev, buf, p, len);

	}

	return rc;

	return 1;

}