[linux.git] / include / media / videobuf-dma-sg.h

/*
 * helper functions for SG DMA video4linux capture buffers
 *
 * The functions expect the hardware being able to scatter gather
 * (i.e. the buffers are not linear in physical memory, but fragmented
 * into PAGE_SIZE chunks).  They also assume the driver does not need
 * to touch the video data.
 *
 * (c) 2007 Mauro Carvalho Chehab, <[email protected]>
 *
 * Highly based on video-buf written originally by:
 * (c) 2001,02 Gerd Knorr <[email protected]>
 * (c) 2006 Mauro Carvalho Chehab, <[email protected]>
 * (c) 2006 Ted Walther and John Sokol
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2
 */
#ifndef _VIDEOBUF_DMA_SG_H
#define _VIDEOBUF_DMA_SG_H

#include <media/videobuf-core.h>

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

/*
 * A small set of helper functions to manage buffers (both userland
 * and kernel) for DMA.
 *
 * videobuf_dma_init_*()
 *	creates a buffer.  The userland version takes a userspace
 *	pointer + length.  The kernel version just wants the size and
 *	does memory allocation too using vmalloc_32().
 *
 * videobuf_dma_*()
 *	see Documentation/DMA-API-HOWTO.txt, these functions to
 *	basically the same.  The map function does also build a
 *	scatterlist for the buffer (and unmap frees it ...)
 *
 * videobuf_dma_free()
 *	no comment ...
 *
 */

struct videobuf_dmabuf {
	u32                 magic;

	/* for userland buffer */
	int                 offset;
	size_t		    size;
	struct page         **pages;

	/* for kernel buffers */
	void                *vaddr;
	struct page         **vaddr_pages;
	dma_addr_t          *dma_addr;
	struct device       *dev;

	/* for overlay buffers (pci-pci dma) */
	dma_addr_t          bus_addr;

	/* common */
	struct scatterlist  *sglist;
	int                 sglen;
	int                 nr_pages;
	int                 direction;
};

struct videobuf_dma_sg_memory {
	u32                 magic;

	/* for mmap'ed buffers */
	struct videobuf_dmabuf  dma;
};

/*
 * Scatter-gather DMA buffer API.
 *
 * These functions provide a simple way to create a page list and a
 * scatter-gather list from a kernel, userspace of physical address and map the
 * memory for DMA operation.
 *
 * Despite the name, this is totally unrelated to videobuf, except that
 * videobuf-dma-sg uses the same API internally.
 */
int videobuf_dma_free(struct videobuf_dmabuf *dma);

int videobuf_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma);
struct videobuf_dmabuf *videobuf_to_dma(struct videobuf_buffer *buf);

void *videobuf_sg_alloc(size_t size);

void videobuf_queue_sg_init(struct videobuf_queue *q,
			 const 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,
			 struct mutex *ext_lock);

#endif /* _VIDEOBUF_DMA_SG_H */
Commit	Line	Data
7a7d9a89	1	/*
0705135e	2	* helper functions for SG DMA video4linux capture buffers
7a7d9a89	3	*
5d6aaf50	4	* The functions expect the hardware being able to scatter gather
7a7d9a89 MCC	5	* (i.e. the buffers are not linear in physical memory, but fragmented
	6	* into PAGE_SIZE chunks). They also assume the driver does not need
	7	* to touch the video data.
	8	*
	9	* (c) 2007 Mauro Carvalho Chehab, <[email protected]>
	10	*
	11	* Highly based on video-buf written originally by:
	12	* (c) 2001,02 Gerd Knorr <[email protected]>
	13	* (c) 2006 Mauro Carvalho Chehab, <[email protected]>
	14	* (c) 2006 Ted Walther and John Sokol
	15	*
	16	* This program is free software; you can redistribute it and/or modify
	17	* it under the terms of the GNU General Public License as published by
	18	* the Free Software Foundation; either version 2
	19	*/
7a02264c PO	20	#ifndef _VIDEOBUF_DMA_SG_H
7a02264c PO	21	#define _VIDEOBUF_DMA_SG_H
7a7d9a89 MCC	22
	23	#include <media/videobuf-core.h>
	24
	25	/* --------------------------------------------------------------------- */
	26
7a7d9a89 MCC	27	/*
	28	* A small set of helper functions to manage buffers (both userland
	29	* and kernel) for DMA.
	30	*
	31	* videobuf_dma_init_*()
	32	* creates a buffer. The userland version takes a userspace
	33	* pointer + length. The kernel version just wants the size and
	34	* does memory allocation too using vmalloc_32().
	35	*
	36	* videobuf_dma_*()
395cf969	37	* see Documentation/DMA-API-HOWTO.txt, these functions to
7a7d9a89 MCC	38	* basically the same. The map function does also build a
	39	* scatterlist for the buffer (and unmap frees it ...)
	40	*
	41	* videobuf_dma_free()
	42	* no comment ...
	43	*
	44	*/
	45
	46	struct videobuf_dmabuf {
	47	u32 magic;
	48
	49	/* for userland buffer */
	50	int offset;
2fc11536	51	size_t size;
7a7d9a89 MCC	52	struct page **pages;
	53
	54	/* for kernel buffers */
bb6dbe74	55	void *vaddr;
7b4eeed1 JH	56	struct page **vaddr_pages;
	57	dma_addr_t *dma_addr;
	58	struct device *dev;
7a7d9a89	59
7a7d9a89 MCC	60	/* for overlay buffers (pci-pci dma) */
	61	dma_addr_t bus_addr;
	62
	63	/* common */
	64	struct scatterlist *sglist;
	65	int sglen;
	66	int nr_pages;
	67	int direction;
	68	};
	69
7a02264c	70	struct videobuf_dma_sg_memory {
7a7d9a89 MCC	71	u32 magic;
	72
	73	/* for mmap'ed buffers */
7a7d9a89 MCC	74	struct videobuf_dmabuf dma;
	75	};
	76
95268403 LP	77	/*
	78	* Scatter-gather DMA buffer API.
	79	*
	80	* These functions provide a simple way to create a page list and a
	81	* scatter-gather list from a kernel, userspace of physical address and map the
	82	* memory for DMA operation.
	83	*
	84	* Despite the name, this is totally unrelated to videobuf, except that
	85	* videobuf-dma-sg uses the same API internally.
	86	*/
7a7d9a89 MCC	87	int videobuf_dma_free(struct videobuf_dmabuf *dma);
7a7d9a89 MCC	88
95268403	89	int videobuf_dma_unmap(struct device dev, struct videobuf_dmabuf dma);
7a02264c	90	struct videobuf_dmabuf videobuf_to_dma(struct videobuf_buffer buf);
7a7d9a89	91
0705135e	92	void *videobuf_sg_alloc(size_t size);
7a7d9a89	93
7a02264c	94	void videobuf_queue_sg_init(struct videobuf_queue *q,
38a54f35	95	const struct videobuf_queue_ops *ops,
0705135e	96	struct device *dev,
7a7d9a89 MCC	97	spinlock_t *irqlock,
	98	enum v4l2_buf_type type,
	99	enum v4l2_field field,
	100	unsigned int msize,
08bff03e HV	101	void *priv,
08bff03e HV	102	struct mutex *ext_lock);
7a7d9a89	103
7a02264c PO	104	#endif /* _VIDEOBUF_DMA_SG_H */
7a02264c PO	105