w9968cf.c

优龙2410linux2.6.8内核源代码

		if (!(cam->transfer_buffer[i] =
		      kmalloc(W9968CF_ISO_PACKETS*p_size, GFP_KERNEL))) {
			DBG(1, "Couldn't allocate memory for the isochronous "
			       "transfer buffers (%u bytes)", 
			    p_size * W9968CF_ISO_PACKETS)
			return -ENOMEM;
		}
		memset(cam->transfer_buffer[i], 0, W9968CF_ISO_PACKETS*p_size);
	}

	/* Allocate memory for the temporary frame buffer */
	if (!(cam->frame_tmp.buffer = rvmalloc(hw_bufsize))) {
		DBG(1, "Couldn't allocate memory for the temporary "
		       "video frame buffer (%lu bytes)", hw_bufsize)
		return -ENOMEM;
	}
	cam->frame_tmp.size = hw_bufsize;
	cam->frame_tmp.number = -1;

	/* Allocate memory for the helper buffer */
	if (w9968cf_vpp) {
		if (!(cam->frame_vpp.buffer = rvmalloc(vpp_bufsize))) {
			DBG(1, "Couldn't allocate memory for the helper buffer"
			       " (%lu bytes)", vpp_bufsize)
			return -ENOMEM;
		}
		cam->frame_vpp.size = vpp_bufsize;
	} else
		cam->frame_vpp.buffer = NULL;

	/* Allocate memory for video frame buffers */
	cam->nbuffers = cam->max_buffers;
	while (cam->nbuffers >= 2) {
		if ((buff = rvmalloc(cam->nbuffers * vpp_bufsize)))
			break;
		else
			cam->nbuffers--;
	}

	if (!buff) {
		DBG(1, "Couldn't allocate memory for the video frame buffers")
		cam->nbuffers = 0;
		return -ENOMEM;
	}

	if (cam->nbuffers != cam->max_buffers)
		DBG(2, "Couldn't allocate memory for %u video frame buffers. "
		       "Only memory for %u buffers has been allocated",
		    cam->max_buffers, cam->nbuffers)

	for (i = 0; i < cam->nbuffers; i++) {
		cam->frame[i].buffer = buff + i*vpp_bufsize;
		cam->frame[i].size = vpp_bufsize;
		cam->frame[i].number = i;
		/* Circular list */
		if (i != cam->nbuffers-1)
			cam->frame[i].next = &cam->frame[i+1];
		else
			cam->frame[i].next = &cam->frame[0];
		cam->frame[i].status = F_UNUSED;
	}

	DBG(5, "Memory successfully allocated")
	return 0;
}



/****************************************************************************
 * USB-specific functions                                                   *
 ****************************************************************************/

/*--------------------------------------------------------------------------
  This is an handler function which is called after the URBs are completed.
  It collects multiple data packets coming from the camera by putting them
  into frame buffers: one or more zero data length data packets are used to
  mark the end of a video frame; the first non-zero data packet is the start
  of the next video frame; if an error is encountered in a packet, the entire
  video frame is discarded and grabbed again.
  If there are no requested frames in the FIFO list, packets are collected into
  a temporary buffer. 
  --------------------------------------------------------------------------*/
static void w9968cf_urb_complete(struct urb *urb, struct pt_regs *regs)
{
	struct w9968cf_device* cam = (struct w9968cf_device*)urb->context;
	struct w9968cf_frame_t** f;
	unsigned int len, status;
	void* pos;
	u8 i;
	int err = 0;

	if ((!cam->streaming) || cam->disconnected) {
		DBG(4, "Got interrupt, but not streaming")
		return;
	}

	/* "(*f)" will be used instead of "cam->frame_current" */
	f = &cam->frame_current;

	/* If a frame has been requested and we are grabbing into  
	   the temporary frame, we'll switch to that requested frame */
	if ((*f) == &cam->frame_tmp && *cam->requested_frame) {
		if (cam->frame_tmp.status == F_GRABBING) {
			w9968cf_pop_frame(cam, &cam->frame_current);
			(*f)->status = F_GRABBING;
			(*f)->length = cam->frame_tmp.length;
			memcpy((*f)->buffer, cam->frame_tmp.buffer,
			       (*f)->length);
			DBG(6, "Switched from temp. frame to frame #%d", 
			    (*f)->number)
		}
	}

	for (i = 0; i < urb->number_of_packets; i++) {
		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 && len != 0) {
			DBG(4, "URB failed, error in data packet "
			       "(error #%u, %s)",
			    status, symbolic(urb_errlist, status))
			(*f)->status = F_ERROR;
			continue;
		}

		if (len) { /* start of frame */

			if ((*f)->status == F_UNUSED) {
				(*f)->status = F_GRABBING;
				(*f)->length = 0;
			}

			/* Buffer overflows shouldn't happen, however...*/
			if ((*f)->length + len > (*f)->size) {
				DBG(4, "Buffer overflow: bad data packets")
				(*f)->status = F_ERROR;
			}

			if ((*f)->status == F_GRABBING) {
				memcpy((*f)->buffer + (*f)->length, pos, len);
				(*f)->length += len;
			}

		} else if ((*f)->status == F_GRABBING) { /* end of frame */

			DBG(6, "Frame #%d successfully grabbed", (*f)->number)

			if (cam->vpp_flag & VPP_DECOMPRESSION) {
				err = w9968cf_vpp->check_headers((*f)->buffer,
				                                 (*f)->length);
				if (err) {
					DBG(4, "Skip corrupted frame: %s",
					    symbolic(decoder_errlist, err))
					(*f)->status = F_UNUSED;
					continue; /* grab this frame again */
				}
			}

			(*f)->status = F_READY;
			(*f)->queued = 0;

			/* Take a pointer to the new frame from the FIFO list.
			   If the list is empty,we'll use the temporary frame*/
			if (*cam->requested_frame)
				w9968cf_pop_frame(cam, &cam->frame_current);
			else {
				cam->frame_current = &cam->frame_tmp;
				(*f)->status = F_UNUSED;
			}

		} else if ((*f)->status == F_ERROR)
			(*f)->status = F_UNUSED; /* grab it again */

		PDBGG("Frame length %lu | pack.#%u | pack.len. %u | state %d",
		      (unsigned long)(*f)->length, i, len, (*f)->status)

	} /* end for */

	/* Resubmit this URB */
	urb->dev = cam->usbdev;
	urb->status = 0;
	spin_lock(&cam->urb_lock);
	if (cam->streaming)
		if ((err = usb_submit_urb(urb, GFP_ATOMIC))) {
			cam->misconfigured = 1;
			DBG(1, "Couldn't resubmit the URB: error %d, %s",
			    err, symbolic(urb_errlist, err))
		}
	spin_unlock(&cam->urb_lock);

	/* Wake up the user process */
	wake_up_interruptible(&cam->wait_queue);
}


/*---------------------------------------------------------------------------
  Setup the URB structures for the isochronous transfer.
  Submit the URBs so that the data transfer begins.
  Return 0 on success, a negative number otherwise.
  ---------------------------------------------------------------------------*/
static int w9968cf_start_transfer(struct w9968cf_device* cam)
{
	struct usb_device *udev = cam->usbdev;
	struct urb* urb;
	const u16 p_size = wMaxPacketSize[cam->altsetting-1];
	u16 w, h, d;
	int vidcapt;
	u32 t_size;
	int err = 0;
	s8 i, j;

	for (i = 0; i < W9968CF_URBS; i++) {
		urb = usb_alloc_urb(W9968CF_ISO_PACKETS, GFP_KERNEL);
		cam->urb[i] = urb;
		if (!urb) {
			for (j = 0; j < i; j++)
				usb_free_urb(cam->urb[j]);
			DBG(1, "Couldn't allocate the URB structures")
			return -ENOMEM;
		}

		urb->dev = udev;
		urb->context = (void*)cam;
		urb->pipe = usb_rcvisocpipe(udev, 1);
		urb->transfer_flags = URB_ISO_ASAP;
		urb->number_of_packets = W9968CF_ISO_PACKETS;
		urb->complete = w9968cf_urb_complete;
		urb->transfer_buffer = cam->transfer_buffer[i];
		urb->transfer_buffer_length = p_size*W9968CF_ISO_PACKETS;
		urb->interval = 1;
		for (j = 0; j < W9968CF_ISO_PACKETS; j++) {
			urb->iso_frame_desc[j].offset = p_size*j;
			urb->iso_frame_desc[j].length = p_size;
		}
	}

	/* Transfer size per frame, in WORD ! */
	d = cam->hw_depth;
	w = cam->hw_width;
	h = cam->hw_height;

	t_size = (w*h*d)/16;

	err = w9968cf_write_reg(cam, 0xbf17, 0x00); /* reset everything */
	err += w9968cf_write_reg(cam, 0xbf10, 0x00); /* normal operation */

	/* Transfer size */
	err += w9968cf_write_reg(cam, t_size & 0xffff, 0x3d); /* low bits */
	err += w9968cf_write_reg(cam, t_size >> 16, 0x3e);    /* high bits */

	if (cam->vpp_flag & VPP_DECOMPRESSION)
		err += w9968cf_upload_quantizationtables(cam);

	vidcapt = w9968cf_read_reg(cam, 0x16); /* read picture settings */
	err += w9968cf_write_reg(cam, vidcapt|0x8000, 0x16); /* capt. enable */

	err += usb_set_interface(udev, 0, cam->altsetting);
	err += w9968cf_write_reg(cam, 0x8a05, 0x3c); /* USB FIFO enable */

	if (err || (vidcapt < 0)) {
		for (i = 0; i < W9968CF_URBS; i++)
			usb_free_urb(cam->urb[i]);
		DBG(1, "Couldn't tell the camera to start the data transfer")
		return err;
	}

	w9968cf_init_framelist(cam);

	/* Begin to grab into the temporary buffer */
	cam->frame_tmp.status = F_UNUSED;
	cam->frame_tmp.queued = 0;
	cam->frame_current = &cam->frame_tmp;

	if (!(cam->vpp_flag & VPP_DECOMPRESSION))
		DBG(5, "Isochronous transfer size: %lu bytes/frame", 
		    (unsigned long)t_size*2)

	DBG(5, "Starting the isochronous transfer...")

	cam->streaming = 1;

	/* Submit the URBs */
	for (i = 0; i < W9968CF_URBS; i++) {
		err = usb_submit_urb(cam->urb[i], GFP_KERNEL);
		if (err) {
			cam->streaming = 0;
			for (j = i-1; j >= 0; j--) {
				usb_kill_urb(cam->urb[j]);
				usb_free_urb(cam->urb[j]);
			}
			DBG(1, "Couldn't send a transfer request to the "
			       "USB core (error #%d, %s)", err, 
			    symbolic(urb_errlist, err))
			return err;
		}
	}

	return 0;
}


/*--------------------------------------------------------------------------
  Stop the isochronous transfer and set alternate setting to 0 (0Mb/s).
  Return 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_stop_transfer(struct w9968cf_device* cam)
{
	struct usb_device *udev = cam->usbdev;
	unsigned long lock_flags;
	int err = 0;
	s8 i;

	if (!cam->streaming)
		return 0;

	/* This avoids race conditions with usb_submit_urb() 
	   in the URB completition handler */
	spin_lock_irqsave(&cam->urb_lock, lock_flags);
	cam->streaming = 0;
	spin_unlock_irqrestore(&cam->urb_lock, lock_flags);

	for (i = W9968CF_URBS-1; i >= 0; i--)
		if (cam->urb[i]) {
			usb_kill_urb(cam->urb[i]);
			usb_free_urb(cam->urb[i]);
			cam->urb[i] = NULL;
		}

	if (cam->disconnected)
		goto exit;

	err = w9968cf_write_reg(cam, 0x0a05, 0x3c); /* stop USB transfer */
	err += usb_set_interface(udev, 0, 0); /* 0 Mb/s */
	err += w9968cf_write_reg(cam, 0x0000, 0x39); /* disable JPEG encoder */
	err += w9968cf_write_reg(cam, 0x0000, 0x16); /* stop video capture */

	if (err) {
		DBG(2, "Failed to tell the camera to stop the isochronous "
		       "transfer. However this is not a critical error.")
		return -EIO;
	}

exit:
	DBG(5, "Isochronous transfer stopped")
	return 0;
}


/*--------------------------------------------------------------------------
  Write a W9968CF register. 
  Return 0 on success, -1 otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_write_reg(struct w9968cf_device* cam, u16 value, u16 index)
{
	struct usb_device* udev = cam->usbdev;
	int res;

	res = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 0,
	                      USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
	                      value, index, NULL, 0, W9968CF_USB_CTRL_TIMEOUT);

	if (res < 0)
		DBG(4, "Failed to write a register "
		       "(value 0x%04X, index 0x%02X, error #%d, %s)",