text: #include <media/drv-intf/saa7146_vv.h>
  
  static int vbi_pixel_to_capture = 720 * 2;
  
  static int vbi_workaround(struct saa7146_dev *dev)
  {
  	struct saa7146_vv *vv = dev->vv_data;
  
  	u32          *cpu;
  	dma_addr_t   dma_addr;
  
  	int count = 0;
  	int i;
  
  	DECLARE_WAITQUEUE(wait, current);
  
  	DEB_VBI("dev:%p\n", dev);
  
  	/* once again, a bug in the saa7146: the brs acquisition
  	   is buggy and especially the BXO-counter does not work
  	   as specified. there is this workaround, but please
  	   don't let me explain it. ;-) */
  
  	cpu = pci_alloc_consistent(dev->pci, 4096, &dma_addr);
  	if (NULL == cpu)
  		return -ENOMEM;
  
  	/* setup some basic programming, just for the workaround */
  	saa7146_write(dev, BASE_EVEN3,	dma_addr);
  	saa7146_write(dev, BASE_ODD3,	dma_addr+vbi_pixel_to_capture);
  	saa7146_write(dev, PROT_ADDR3,	dma_addr+4096);
  	saa7146_write(dev, PITCH3,	vbi_pixel_to_capture);
  	saa7146_write(dev, BASE_PAGE3,	0x0);
  	saa7146_write(dev, NUM_LINE_BYTE3, (2<<16)|((vbi_pixel_to_capture)<<0));
  	saa7146_write(dev, MC2, MASK_04|MASK_20);
  
  	/* load brs-control register */
  	WRITE_RPS1(CMD_WR_REG | (1 << 8) | (BRS_CTRL/4));
  	/* BXO = 1h, BRS to outbound */
  	WRITE_RPS1(0xc000008c);
  	/* wait for vbi_a or vbi_b*/
  	if ( 0 != (SAA7146_USE_PORT_B_FOR_VBI & dev->ext_vv_data->flags)) {
  		DEB_D("...using port b\n");
  		WRITE_RPS1(CMD_PAUSE | CMD_OAN | CMD_SIG1 | CMD_E_FID_B);
  		WRITE_RPS1(CMD_PAUSE | CMD_OAN | CMD_SIG1 | CMD_O_FID_B);
  /*
  		WRITE_RPS1(CMD_PAUSE | MASK_09);
  */
  	} else {
  		DEB_D("...using port a\n");
  		WRITE_RPS1(CMD_PAUSE | MASK_10);
  	}
  	/* upload brs */
  	WRITE_RPS1(CMD_UPLOAD | MASK_08);
  	/* load brs-control register */
  	WRITE_RPS1(CMD_WR_REG | (1 << 8) | (BRS_CTRL/4));
  	/* BYO = 1, BXO = NQBIL (=1728 for PAL, for NTSC this is 858*2) - NumByte3 (=1440) = 288 */
  	WRITE_RPS1(((1728-(vbi_pixel_to_capture)) << 7) | MASK_19);
  	/* wait for brs_done */
  	WRITE_RPS1(CMD_PAUSE | MASK_08);
  	/* upload brs */
  	WRITE_RPS1(CMD_UPLOAD | MASK_08);
  	/* load video-dma3 NumLines3 and NumBytes3 */
  	WRITE_RPS1(CMD_WR_REG | (1 << 8) | (NUM_LINE_BYTE3/4));
  	/* dev->vbi_count*2 lines, 720 pixel (= 1440 Bytes) */
  	WRITE_RPS1((2 << 16) | (vbi_pixel_to_capture));
  	/* load brs-control register */
  	WRITE_RPS1(CMD_WR_REG | (1 << 8) | (BRS_CTRL/4));
  	/* Set BRS right: note: this is an experimental value for BXO (=> PAL!) */
  	WRITE_RPS1((540 << 7) | (5 << 19));  // 5 == vbi_start
  	/* wait for brs_done */
  	WRITE_RPS1(CMD_PAUSE | MASK_08);
  	/* upload brs and video-dma3*/
  	WRITE_RPS1(CMD_UPLOAD | MASK_08 | MASK_04);
  	/* load mc2 register: enable dma3 */
  	WRITE_RPS1(CMD_WR_REG | (1 << 8) | (MC1/4));
  	WRITE_RPS1(MASK_20 | MASK_04);
  	/* generate interrupt */
  	WRITE_RPS1(CMD_INTERRUPT);
  	/* stop rps1 */
  	WRITE_RPS1(CMD_STOP);
  
  	/* we have to do the workaround twice to be sure that
  	   everything is ok */
  	for(i = 0; i < 2; i++) {
  
  		/* indicate to the irq handler that we do the workaround */
  		saa7146_write(dev, MC2, MASK_31|MASK_15);
  
  		saa7146_write(dev, NUM_LINE_BYTE3, (1<<16)|(2<<0));
  		saa7146_write(dev, MC2, MASK_04|MASK_20);
  
  		/* enable rps1 irqs */
  		SAA7146_IER_ENABLE(dev,MASK_28);
  
  		/* prepare to wait to be woken up by the irq-handler */
  		add_wait_queue(&vv->vbi_wq, &wait);
  		set_current_state(TASK_INTERRUPTIBLE);
  
  		/* start rps1 to enable workaround */
  		saa7146_write(dev, RPS_ADDR1, dev->d_rps1.dma_handle);
  		saa7146_write(dev, MC1, (MASK_13 | MASK_29));
  
  		schedule();
  
  		DEB_VBI("brs bug workaround %d/1\n", i);
  
  		remove_wait_queue(&vv->vbi_wq, &wait);
  		__set_current_state(TASK_RUNNING);
  
  		/* disable rps1 irqs */
  		SAA7146_IER_DISABLE(dev,MASK_28);
  
  		/* stop video-dma3 */
  		saa7146_write(dev, MC1, MASK_20);
  
  		if(signal_pending(current)) {
  
  			DEB_VBI("aborted (rps:0x%08x)\n",
  				saa7146_read(dev, RPS_ADDR1));
  
  			/* stop rps1 for sure */
  			saa7146_write(dev, MC1, MASK_29);
  
  			pci_free_consistent(dev->pci, 4096, cpu, dma_addr);
  			return -EINTR;
  		}
  	}
  
  	pci_free_consistent(dev->pci, 4096, cpu, dma_addr);
  	return 0;
  }
  
  static void saa7146_set_vbi_capture(struct saa7146_dev *dev, struct saa7146_buf *buf, struct saa7146_buf *next)
  {
  	struct saa7146_vv *vv = dev->vv_data;
  
  	struct saa7146_video_dma vdma3;
  
  	int count = 0;
  	unsigned long e_wait = vv->current_hps_sync == SAA7146_HPS_SYNC_PORT_A ? CMD_E_FID_A : CMD_E_FID_B;
  	unsigned long o_wait = vv->current_hps_sync == SAA7146_HPS_SYNC_PORT_A ? CMD_O_FID_A : CMD_O_FID_B;
  
  /*
  	vdma3.base_even	= 0xc8000000+2560*70;
  	vdma3.base_odd	= 0xc8000000;
  	vdma3.prot_addr	= 0xc8000000+2560*164;
  	vdma3.pitch	= 2560;
  	vdma3.base_page	= 0;
  	vdma3.num_line_byte = (64<<16)|((vbi_pixel_to_capture)<<0); // set above!
  */
  	vdma3.base_even	= buf->pt[2].offset;
  	vdma3.base_odd	= buf->pt[2].offset + 16 * vbi_pixel_to_capture;
  	vdma3.prot_addr	= buf->pt[2].offset + 16 * 2 * vbi_pixel_to_capture;
  	vdma3.pitch	= vbi_pixel_to_capture;
  	vdma3.base_page	= buf->pt[2].dma | ME1;
  	vdma3.num_line_byte = (16 << 16) | vbi_pixel_to_capture;
  
  	saa7146_write_out_dma(dev, 3, &vdma3);
  
  	/* write beginning of rps-program */
  	count = 0;
  
  	/* wait for o_fid_a/b / e_fid_a/b toggle only if bit 1 is not set */
  
  	/* we don't wait here for the first field anymore. this is different from the video
  	   capture and might cause that the first buffer is only half filled (with only
  	   one field). but since this is some sort of streaming data, this is not that negative.
  	   but by doing this, we can use the whole engine from videobuf-dma-sg.c... */
  
  /*
  	WRITE_RPS1(CMD_PAUSE | CMD_OAN | CMD_SIG1 | e_wait);
  	WRITE_RPS1(CMD_PAUSE | CMD_OAN | CMD_SIG1 | o_wait);
  */
  	/* set bit 1 */
  	WRITE_RPS1(CMD_WR_REG | (1 << 8) | (MC2/4));
  	WRITE_RPS1(MASK_28 | MASK_12);
  
  	/* turn on video-dma3 */
  	WRITE_RPS1(CMD_WR_REG_MASK | (MC1/4));
  	WRITE_RPS1(MASK_04 | MASK_20);			/* => mask */
  	WRITE_RPS1(MASK_04 | MASK_20);			/* => values */
  
  	/* wait for o_fid_a/b / e_fid_a/b toggle */
  	WRITE_RPS1(CMD_PAUSE | o_wait);
  	WRITE_RPS1(CMD_PAUSE | e_wait);
  
  	/* generate interrupt */
  	WRITE_RPS1(CMD_INTERRUPT);
  
  	/* stop */
  	WRITE_RPS1(CMD_STOP);
  
  	/* enable rps1 irqs */
  	SAA7146_IER_ENABLE(dev, MASK_28);
  
  	/* write the address of the rps-program */
  	saa7146_write(dev, RPS_ADDR1, dev->d_rps1.dma_handle);
  
  	/* turn on rps */
  	saa7146_write(dev, MC1, (MASK_13 | MASK_29));
  }
  
  static int buffer_activate(struct saa7146_dev *dev,
  			   struct saa7146_buf *buf,
  			   struct saa7146_buf *next)
  {
  	struct saa7146_vv *vv = dev->vv_data;
  	buf->vb.state = VIDEOBUF_ACTIVE;
  
  	DEB_VBI("dev:%p, buf:%p, next:%p\n", dev, buf, next);
  	saa7146_set_vbi_capture(dev,buf,next);
  
  	mod_timer(&vv->vbi_dmaq.timeout, jiffies+BUFFER_TIMEOUT);
  	return 0;
  }
  
  static int buffer_prepare(struct videobuf_queue *q, struct videobuf_buffer *vb,enum v4l2_field field)
  {
  	struct file *file = q->priv_data;
  	struct saa7146_fh *fh = file->private_data;
  	struct saa7146_dev *dev = fh->dev;
  	struct saa7146_buf *buf = (struct saa7146_buf *)vb;
  
  	int err = 0;
  	int lines, llength, size;
  
  	lines   = 16 * 2 ; /* 2 fields */
  	llength = vbi_pixel_to_capture;
  	size = lines * llength;
  
  	DEB_VBI("vb:%p\n", vb);
  
  	if (0 != buf->vb.baddr  &&  buf->vb.bsize < size) {
  		DEB_VBI("size mismatch\n");
  		return -EINVAL;
  	}
  
  	if (buf->vb.size != size)
  		saa7146_dma_free(dev,q,buf);
  
  	if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
  		struct videobuf_dmabuf *dma=videobuf_to_dma(&buf->vb);
  
  		buf->vb.width  = llength;
  		buf->vb.height = lines;
  		buf->vb.size   = size;
  		buf->vb.field  = field;	// FIXME: check this
  
  		saa7146_pgtable_free(dev->pci, &buf->pt[2]);
  		saa7146_pgtable_alloc(dev->pci, &buf->pt[2]);
  
  		err = videobuf_iolock(q,&buf->vb, NULL);
  		if (err)
  			goto oops;
  		err = saa7146_pgtable_build_single(dev->pci, &buf->pt[2],
  						 dma->sglist, dma->sglen);
  		if (0 != err)
  			return err;
  	}
  	buf->vb.state = VIDEOBUF_PREPARED;
  	buf->activate = buffer_activate;
  
  	return 0;
  
   oops:
  	DEB_VBI("error out\n");
  	saa7146_dma_free(dev,q,buf);
  
  	return err;
  }
  
  static int buffer_setup(struct videobuf_queue *q, unsigned int *count, unsigned int *size)
  {
  	int llength,lines;
  
  	lines   = 16 * 2 ; /* 2 fields */
  	llength = vbi_pixel_to_capture;
  
  	*size = lines * llength;
  	*count = 2;
  
  	DEB_VBI("count:%d, size:%d\n", *count, *size);
  
  	return 0;
  }
  
  static void buffer_queue(struct videobuf_queue *q, struct videobuf_buffer *vb)
  {
  	struct file *file = q->priv_data;
  	struct saa7146_fh *fh = file->private_data;
  	struct saa7146_dev *dev = fh->dev;
  	struct saa7146_vv *vv = dev->vv_data;
  	struct saa7146_buf *buf = (struct saa7146_buf *)vb;
  
  	DEB_VBI("vb:%p\n", vb);
  	saa7146_buffer_queue(dev, &vv->vbi_dmaq, buf);
  }
  
  static void buffer_release(struct videobuf_queue *q, struct videobuf_buffer *vb)
  {
  	struct file *file = q->priv_data;
  	struct saa7146_fh *fh   = file->private_data;
  	struct saa7146_dev *dev = fh->dev;
  	struct saa7146_buf *buf = (struct saa7146_buf *)vb;
  
  	DEB_VBI("vb:%p\n", vb);
  	saa7146_dma_free(dev,q,buf);
  }
  
  static struct videobuf_queue_ops vbi_qops = {
  	.buf_setup    = buffer_setup,
  	.buf_prepare  = buffer_prepare,
  	.buf_queue    = buffer_queue,
  	.buf_release  = buffer_release,
  };
  
  /* ------------------------------------------------------------------ */
  
  static void vbi_stop(struct saa7146_fh *fh, struct file *file)
  {
  	struct saa7146_dev *dev = fh->dev;
  	struct saa7146_vv *vv = dev->vv_data;
  	unsigned long flags;
  	DEB_VBI("dev:%p, fh:%p\n", dev, fh);
  
  	spin_lock_irqsave(&dev->slock,flags);
  
  	/* disable rps1  */
  	saa7146_write(dev, MC1, MASK_29);
  
  	/* disable rps1 irqs */
  	SAA7146_IER_DISABLE(dev, MASK_28);
  
  	/* shut down dma 3 transfers */
  	saa7146_write(dev, MC1, MASK_20);
  
  	if (vv->vbi_dmaq.curr)
  		saa7146_buffer_finish(dev, &vv->vbi_dmaq, VIDEOBUF_DONE);
  
  	videobuf_queue_cancel(&fh->vbi_q);
  
  	vv->vbi_streaming = NULL;
  
  	del_timer(&vv->vbi_dmaq.timeout);
  	del_timer(&vv->vbi_read_timeout);
  
  	spin_unlock_irqrestore(&dev->slock, flags);
  }
  
  static void vbi_read_timeout(unsigned long data)
  {
  	struct file *file = (struct file*)data;
  	struct saa7146_fh *fh = file->private_data;
  	struct saa7146_dev *dev = fh->dev;
  
  	DEB_VBI("dev:%p, fh:%p\n", dev, fh);
  
  	vbi_stop(fh, file);
  }
  
  static void vbi_init(struct saa7146_dev *dev, struct saa7146_vv *vv)
  {
  	DEB_VBI("dev:%p\n", dev);
  
  	INIT_LIST_HEAD(&vv->vbi_dmaq.queue);
  
  	setup_timer(&vv->vbi_dmaq.timeout, saa7146_buffer_timeout,
  		    (unsigned long)(&vv->vbi_dmaq));
  	vv->vbi_dmaq.dev              = dev;
  
  	init_waitqueue_head(&vv->vbi_wq);
  }
  
  static int vbi_open(struct saa7146_dev *dev, struct file *file)
  {
  	struct saa7146_fh *fh = file->private_data;
  	struct saa7146_vv *vv = fh->dev->vv_data;
  
  	u32 arbtr_ctrl	= saa7146_read(dev, PCI_BT_V1);
  	int ret = 0;
  
  	DEB_VBI("dev:%p, fh:%p\n", dev, fh);
  
  	ret = saa7146_res_get(fh, RESOURCE_DMA3_BRS);
  	if (0 == ret) {
  		DEB_S("cannot get vbi RESOURCE_DMA3_BRS resource\n");
  		return -EBUSY;
  	}
  
  	/* adjust arbitrition control for video dma 3 */
  	arbtr_ctrl &= ~0x1f0000;
  	arbtr_ctrl |=  0x1d0000;
  	saa7146_write(dev, PCI_BT_V1, arbtr_ctrl);
  	saa7146_write(dev, MC2, (MASK_04|MASK_20));
  
  	videobuf_queue_sg_init(&fh->vbi_q, &vbi_qops,
  			    &dev->pci->dev, &dev->slock,
  			    V4L2_BUF_TYPE_VBI_CAPTURE,
  			    V4L2_FIELD_SEQ_TB, // FIXME: does this really work?
  			    sizeof(struct saa7146_buf),
  			    file, &dev->v4l2_lock);
  
  	vv->vbi_read_timeout.function = vbi_read_timeout;
  	vv->vbi_read_timeout.data = (unsigned long)file;
  
  	/* initialize the brs */
  	if ( 0 != (SAA7146_USE_PORT_B_FOR_VBI & dev->ext_vv_data->flags)) {
  		saa7146_write(dev, BRS_CTRL, MASK_30|MASK_29 | (7 << 19));
  	} else {
  		saa7146_write(dev, BRS_CTRL, 0x00000001);
  
  		if (0 != (ret = vbi_workaround(dev))) {
  			DEB_VBI("vbi workaround failed!\n");
  			/* return ret;*/
  		}
  	}
  
  	/* upload brs register */
  	saa7146_write(dev, MC2, (MASK_08|MASK_24));
  	return 0;
  }
  
  static void vbi_close(struct saa7146_dev *dev, struct file *file)
  {
  	struct saa7146_fh *fh = file->private_data;
  	struct saa7146_vv *vv = dev->vv_data;
  	DEB_VBI("dev:%p, fh:%p\n", dev, fh);
  
  	if( fh == vv->vbi_streaming ) {
  		vbi_stop(fh, file);
  	}
  	saa7146_res_free(fh, RESOURCE_DMA3_BRS);
  }
  
  static void vbi_irq_done(struct saa7146_dev *dev, unsigned long status)
  {
  	struct saa7146_vv *vv = dev->vv_data;
  	spin_lock(&dev->slock);
  
  	if (vv->vbi_dmaq.curr) {
  		DEB_VBI("dev:%p, curr:%p\n", dev, vv->vbi_dmaq.curr);
  		/* this must be += 2, one count for each field */
  		vv->vbi_fieldcount+=2;
  		vv->vbi_dmaq.curr->vb.field_count = vv->vbi_fieldcount;
  		saa7146_buffer_finish(dev, &vv->vbi_dmaq, VIDEOBUF_DONE);
  	} else {
  		DEB_VBI("dev:%p\n", dev);
  	}
  	saa7146_buffer_next(dev, &vv->vbi_dmaq, 1);
  
  	spin_unlock(&dev->slock);
  }
  
  static ssize_t vbi_read(struct file *file, char __user *data, size_t count, loff_t *ppos)
  {
  	struct saa7146_fh *fh = file->private_data;
  	struct saa7146_dev *dev = fh->dev;
  	struct saa7146_vv *vv = dev->vv_data;
  	ssize_t ret = 0;
  
  	DEB_VBI("dev:%p, fh:%p\n", dev, fh);
  
  	if( NULL == vv->vbi_streaming ) {
  		// fixme: check if dma3 is available
  		// fixme: activate vbi engine here if necessary. (really?)
  		vv->vbi_streaming = fh;
  	}
  
  	if( fh != vv->vbi_streaming ) {
  		DEB_VBI("open %p is already using vbi capture\n",
  			vv->vbi_streaming);
  		return -EBUSY;
  	}
  
  	mod_timer(&vv->vbi_read_timeout, jiffies+BUFFER_TIMEOUT);
  	ret = videobuf_read_stream(&fh->vbi_q, data, count, ppos, 1,
  				   file->f_flags & O_NONBLOCK);
  /*
  	printk("BASE_ODD3:      0x%08x\n", saa7146_read(dev, BASE_ODD3));
  	printk("BASE_EVEN3:     0x%08x\n", saa7146_read(dev, BASE_EVEN3));
  	printk("PROT_ADDR3:     0x%08x\n", saa7146_read(dev, PROT_ADDR3));
  	printk("PITCH3:         0x%08x\n", saa7146_read(dev, PITCH3));
  	printk("BASE_PAGE3:     0x%08x\n", saa7146_read(dev, BASE_PAGE3));
  	printk("NUM_LINE_BYTE3: 0x%08x\n", saa7146_read(dev, NUM_LINE_BYTE3));
  	printk("BRS_CTRL:       0x%08x\n", saa7146_read(dev, BRS_CTRL));
  */
  	return ret;
  }
  
  struct saa7146_use_ops saa7146_vbi_uops = {
  	.init		= vbi_init,
  	.open		= vbi_open,
  	.release	= vbi_close,
  	.irq_done	= vbi_irq_done,
  	.read		= vbi_read,
  };
  