videobuf-dma-sg.c

trident tm5600的linux驱动

#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
static struct page*
videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr,
		   int *type)
{
	struct page *page;

	dprintk(3,"nopage: fault @ %08lx [vma %08lx-%08lx]\n",
		vaddr,vma->vm_start,vma->vm_end);
	if (vaddr > vma->vm_end)
		return NOPAGE_SIGBUS;
	page = alloc_page(GFP_USER | __GFP_DMA32);
	if (!page)
		return NOPAGE_OOM;
	clear_user_page(page_address(page), vaddr, page);
	if (type)
		*type = VM_FAULT_MINOR;
	return page;
}
#else
static int
videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct page *page;

	dprintk(3,"fault: fault @ %08lx [vma %08lx-%08lx]\n",
		(unsigned long)vmf->virtual_address,vma->vm_start,vma->vm_end);
	page = alloc_page(GFP_USER | __GFP_DMA32);
	if (!page)
		return VM_FAULT_OOM;
	clear_user_page(page_address(page), (unsigned long)vmf->virtual_address,
			page);
	vmf->page = page;
	return 0;
}
#endif

static struct vm_operations_struct videobuf_vm_ops =
{
	.open     = videobuf_vm_open,
	.close    = videobuf_vm_close,
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
	.nopage   = videobuf_vm_nopage,
#else
	.fault    = videobuf_vm_fault,
#endif
};

/* ---------------------------------------------------------------------
 * SG handlers for the generic methods
 */

/* Allocated area consists on 3 parts:
	struct video_buffer
	struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
	struct videobuf_dma_sg_memory
 */

static void *__videobuf_alloc(size_t size)
{
	struct videobuf_dma_sg_memory *mem;
	struct videobuf_buffer *vb;

	vb = kzalloc(size+sizeof(*mem),GFP_KERNEL);

	mem = vb->priv = ((char *)vb)+size;
	mem->magic=MAGIC_SG_MEM;

	videobuf_dma_init(&mem->dma);

	dprintk(1,"%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
		__func__,vb,(long)sizeof(*vb),(long)size-sizeof(*vb),
		mem,(long)sizeof(*mem));

	return vb;
}

static void *__videobuf_to_vmalloc (struct videobuf_buffer *buf)
{
	struct videobuf_dma_sg_memory *mem = buf->priv;
	BUG_ON(!mem);

	MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);

	return mem->dma.vmalloc;
}

static int __videobuf_iolock (struct videobuf_queue* q,
			      struct videobuf_buffer *vb,
			      struct v4l2_framebuffer *fbuf)
{
	int err,pages;
	dma_addr_t bus;
	struct videobuf_dma_sg_memory *mem = vb->priv;
	BUG_ON(!mem);

	MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);

	switch (vb->memory) {
	case V4L2_MEMORY_MMAP:
	case V4L2_MEMORY_USERPTR:
		if (0 == vb->baddr) {
			/* no userspace addr -- kernel bounce buffer */
			pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
			err = videobuf_dma_init_kernel( &mem->dma,
							DMA_FROM_DEVICE,
							pages );
			if (0 != err)
				return err;
		} else if (vb->memory == V4L2_MEMORY_USERPTR) {
			/* dma directly to userspace */
			err = videobuf_dma_init_user( &mem->dma,
						      DMA_FROM_DEVICE,
						      vb->baddr,vb->bsize );
			if (0 != err)
				return err;
		} else {
			/* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP
			buffers can only be called from videobuf_qbuf
			we take current->mm->mmap_sem there, to prevent
			locking inversion, so don't take it here */

			err = videobuf_dma_init_user_locked(&mem->dma,
						      DMA_FROM_DEVICE,
						      vb->baddr, vb->bsize);
			if (0 != err)
				return err;
		}
		break;
	case V4L2_MEMORY_OVERLAY:
		if (NULL == fbuf)
			return -EINVAL;
		/* FIXME: need sanity checks for vb->boff */
		/*
		 * Using a double cast to avoid compiler warnings when
		 * building for PAE. Compiler doesn't like direct casting
		 * of a 32 bit ptr to 64 bit integer.
		 */
		bus   = (dma_addr_t)(unsigned long)fbuf->base + vb->boff;
		pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
		err = videobuf_dma_init_overlay(&mem->dma, DMA_FROM_DEVICE,
						bus, pages);
		if (0 != err)
			return err;
		break;
	default:
		BUG();
	}
	err = videobuf_dma_map(q, &mem->dma);
	if (0 != err)
		return err;

	return 0;
}

static int __videobuf_sync(struct videobuf_queue *q,
			   struct videobuf_buffer *buf)
{
	struct videobuf_dma_sg_memory *mem = buf->priv;
	BUG_ON(!mem);
	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);

	return	videobuf_dma_sync(q,&mem->dma);
}

static int __videobuf_mmap_free(struct videobuf_queue *q)
{
	int i;

	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
		if (q->bufs[i]) {
			if (q->bufs[i]->map)
				return -EBUSY;
		}
	}

	return 0;
}

static int __videobuf_mmap_mapper(struct videobuf_queue *q,
			 struct vm_area_struct *vma)
{
	struct videobuf_dma_sg_memory *mem;
	struct videobuf_mapping *map;
	unsigned int first,last,size,i;
	int retval;

	retval = -EINVAL;
	if (!(vma->vm_flags & VM_WRITE)) {
		dprintk(1,"mmap app bug: PROT_WRITE please\n");
		goto done;
	}
	if (!(vma->vm_flags & VM_SHARED)) {
		dprintk(1,"mmap app bug: MAP_SHARED please\n");
		goto done;
	}

	/* This function maintains backwards compatibility with V4L1 and will
	 * map more than one buffer if the vma length is equal to the combined
	 * size of multiple buffers than it will map them together.  See
	 * VIDIOCGMBUF in the v4l spec
	 *
	 * TODO: Allow drivers to specify if they support this mode
	 */

	/* look for first buffer to map */
	for (first = 0; first < VIDEO_MAX_FRAME; first++) {
		if (NULL == q->bufs[first])
			continue;
		mem=q->bufs[first]->priv;
		BUG_ON(!mem);
		MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);

		if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
			continue;
		if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
			break;
	}
	if (VIDEO_MAX_FRAME == first) {
		dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
			(vma->vm_pgoff << PAGE_SHIFT));
		goto done;
	}

	/* look for last buffer to map */
	for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
		if (NULL == q->bufs[last])
			continue;
		if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
			continue;
		if (q->bufs[last]->map) {
			retval = -EBUSY;
			goto done;
		}
		size += q->bufs[last]->bsize;
		if (size == (vma->vm_end - vma->vm_start))
			break;
	}
	if (VIDEO_MAX_FRAME == last) {
		dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n",
			(vma->vm_end - vma->vm_start));
		goto done;
	}

	/* create mapping + update buffer list */
	retval = -ENOMEM;
	map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
	if (NULL == map)
		goto done;

	size = 0;
	for (i = first; i <= last; i++) {
		if (NULL == q->bufs[i])
			continue;
		q->bufs[i]->map   = map;
		q->bufs[i]->baddr = vma->vm_start + size;
		size += q->bufs[i]->bsize;
	}

	map->count    = 1;
	map->start    = vma->vm_start;
	map->end      = vma->vm_end;
	map->q        = q;
	vma->vm_ops   = &videobuf_vm_ops;
	vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
	vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
	vma->vm_private_data = map;
	dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",
		map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last);
	retval = 0;

 done:
	return retval;
}

static int __videobuf_copy_to_user ( struct videobuf_queue *q,
				char __user *data, size_t count,
				int nonblocking )
{
	struct videobuf_dma_sg_memory *mem = q->read_buf->priv;
	BUG_ON(!mem);
	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);

	/* copy to userspace */
	if (count > q->read_buf->size - q->read_off)
		count = q->read_buf->size - q->read_off;

	if (copy_to_user(data, mem->dma.vmalloc+q->read_off, count))
		return -EFAULT;

	return count;
}

static int __videobuf_copy_stream ( struct videobuf_queue *q,
				char __user *data, size_t count, size_t pos,
				int vbihack, int nonblocking )
{
	unsigned int  *fc;
	struct videobuf_dma_sg_memory *mem = q->read_buf->priv;
	BUG_ON(!mem);
	MAGIC_CHECK(mem->magic,MAGIC_SG_MEM);

	if (vbihack) {
		/* dirty, undocumented hack -- pass the frame counter
			* within the last four bytes of each vbi data block.
			* We need that one to maintain backward compatibility
			* to all vbi decoding software out there ... */
		fc  = (unsigned int*)mem->dma.vmalloc;
		fc += (q->read_buf->size>>2) -1;
		*fc = q->read_buf->field_count >> 1;
		dprintk(1,"vbihack: %d\n",*fc);
	}

	/* copy stuff using the common method */
	count = __videobuf_copy_to_user (q,data,count,nonblocking);

	if ( (count==-EFAULT) && (0 == pos) )
		return -EFAULT;

	return count;
}

static struct videobuf_qtype_ops sg_ops = {
	.magic        = MAGIC_QTYPE_OPS,

	.alloc        = __videobuf_alloc,
	.iolock       = __videobuf_iolock,
	.sync         = __videobuf_sync,
	.mmap_free    = __videobuf_mmap_free,
	.mmap_mapper  = __videobuf_mmap_mapper,
	.video_copy_to_user = __videobuf_copy_to_user,
	.copy_stream  = __videobuf_copy_stream,
	.vmalloc      = __videobuf_to_vmalloc,
};

void *videobuf_sg_alloc(size_t size)
{
	struct videobuf_queue q;

	/* Required to make generic handler to call __videobuf_alloc */
	q.int_ops = &sg_ops;

	q.msize = size;

	return videobuf_alloc(&q);
}

void videobuf_queue_sg_init(struct videobuf_queue* q,
			 struct videobuf_queue_ops *ops,
			 struct device *dev,
			 spinlock_t *irqlock,
			 enum v4l2_buf_type type,
			 enum v4l2_field field,
			 unsigned int msize,
			 void *priv)
{
	videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
				 priv, &sg_ops);
}

/* --------------------------------------------------------------------- */

EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg);

EXPORT_SYMBOL_GPL(videobuf_to_dma);
EXPORT_SYMBOL_GPL(videobuf_dma_init);
EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
EXPORT_SYMBOL_GPL(videobuf_dma_map);
EXPORT_SYMBOL_GPL(videobuf_dma_sync);
EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
EXPORT_SYMBOL_GPL(videobuf_dma_free);

EXPORT_SYMBOL_GPL(videobuf_sg_dma_map);
EXPORT_SYMBOL_GPL(videobuf_sg_dma_unmap);
EXPORT_SYMBOL_GPL(videobuf_sg_alloc);

EXPORT_SYMBOL_GPL(videobuf_queue_sg_init);

/*
 * Local variables:
 * c-basic-offset: 8
 * End:
 */