[net-next-2.6.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, <mchehab@infradead.org>
 *
 * Highly based on video-buf written originally by:
 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
 * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
 * (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>

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

/*
 * Return a scatterlist for some page-aligned vmalloc()'ed memory
 * block (NULL on errors).  Memory for the scatterlist is allocated
 * using kmalloc.  The caller must free the memory.
 */
struct scatterlist *videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages);

/*
 * Return a scatterlist for a an array of userpages (NULL on errors).
 * Memory for the scatterlist is allocated using kmalloc.  The caller
 * must free the memory.
 */
struct scatterlist *videobuf_pages_to_sg(struct page **pages, int nr_pages,
					 int offset);

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

/*
 * 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/PCI/PCI-DMA-mapping.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;
	struct page         **pages;

	/* for kernel buffers */
	void                *vmalloc;

	/* 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;
};

void videobuf_dma_init(struct videobuf_dmabuf *dma);
int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
			   unsigned long data, unsigned long size);
int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
			     int nr_pages);
int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
			      dma_addr_t addr, int nr_pages);
int videobuf_dma_free(struct videobuf_dmabuf *dma);

int videobuf_dma_map(struct videobuf_queue *q, struct videobuf_dmabuf *dma);
int videobuf_dma_unmap(struct videobuf_queue *q, 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);

/*FIXME: these variants are used only on *-alsa code, where videobuf is
 * used without queue
 */
int videobuf_sg_dma_map(struct device *dev, struct videobuf_dmabuf *dma);
int videobuf_sg_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma);

#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, <mchehab@infradead.org>
	10	*
	11	* Highly based on video-buf written originally by:
	12	* (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
	13	* (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
	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
	27	/*
	28	* Return a scatterlist for some page-aligned vmalloc()'ed memory
	29	* block (NULL on errors). Memory for the scatterlist is allocated
	30	* using kmalloc. The caller must free the memory.
	31	*/
7a02264c	32	struct scatterlist videobuf_vmalloc_to_sg(unsigned char virt, int nr_pages);
7a7d9a89 MCC	33
	34	/*
	35	* Return a scatterlist for a an array of userpages (NULL on errors).
	36	* Memory for the scatterlist is allocated using kmalloc. The caller
	37	* must free the memory.
	38	*/
7a02264c	39	struct scatterlist videobuf_pages_to_sg(struct page *pages, int nr_pages,
7a7d9a89 MCC	40	int offset);
	41
	42	/* --------------------------------------------------------------------- */
	43
	44	/*
	45	* A small set of helper functions to manage buffers (both userland
	46	* and kernel) for DMA.
	47	*
	48	* videobuf_dma_init_*()
	49	* creates a buffer. The userland version takes a userspace
	50	* pointer + length. The kernel version just wants the size and
	51	* does memory allocation too using vmalloc_32().
	52	*
	53	* videobuf_dma_*()
5872fb94	54	* see Documentation/PCI/PCI-DMA-mapping.txt, these functions to
7a7d9a89 MCC	55	* basically the same. The map function does also build a
	56	* scatterlist for the buffer (and unmap frees it ...)
	57	*
	58	* videobuf_dma_free()
	59	* no comment ...
	60	*
	61	*/
	62
	63	struct videobuf_dmabuf {
	64	u32 magic;
	65
	66	/* for userland buffer */
	67	int offset;
	68	struct page **pages;
	69
	70	/* for kernel buffers */
	71	void *vmalloc;
	72
7a7d9a89 MCC	73	/* for overlay buffers (pci-pci dma) */
	74	dma_addr_t bus_addr;
	75
	76	/* common */
	77	struct scatterlist *sglist;
	78	int sglen;
	79	int nr_pages;
	80	int direction;
	81	};
	82
7a02264c	83	struct videobuf_dma_sg_memory {
7a7d9a89 MCC	84	u32 magic;
	85
	86	/* for mmap'ed buffers */
7a7d9a89 MCC	87	struct videobuf_dmabuf dma;
	88	};
	89
7a7d9a89 MCC	90	void videobuf_dma_init(struct videobuf_dmabuf *dma);
	91	int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
	92	unsigned long data, unsigned long size);
	93	int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
	94	int nr_pages);
	95	int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
	96	dma_addr_t addr, int nr_pages);
	97	int videobuf_dma_free(struct videobuf_dmabuf *dma);
	98
7a02264c	99	int videobuf_dma_map(struct videobuf_queue q, struct videobuf_dmabuf dma);
7a02264c PO	100	int videobuf_dma_unmap(struct videobuf_queue q, struct videobuf_dmabuf dma);
7a02264c PO	101	struct videobuf_dmabuf videobuf_to_dma(struct videobuf_buffer buf);
7a7d9a89	102
0705135e	103	void *videobuf_sg_alloc(size_t size);
7a7d9a89	104
7a02264c	105	void videobuf_queue_sg_init(struct videobuf_queue *q,
38a54f35	106	const struct videobuf_queue_ops *ops,
0705135e	107	struct device *dev,
7a7d9a89 MCC	108	spinlock_t *irqlock,
	109	enum v4l2_buf_type type,
	110	enum v4l2_field field,
	111	unsigned int msize,
	112	void *priv);
	113
7a02264c PO	114	/FIXME: these variants are used only on -alsa code, where videobuf is
	115	* used without queue
	116	*/
0705135e GL	117	int videobuf_sg_dma_map(struct device dev, struct videobuf_dmabuf dma);
0705135e GL	118	int videobuf_sg_dma_unmap(struct device dev, struct videobuf_dmabuf dma);
7a7d9a89	119
7a02264c PO	120	#endif /* _VIDEOBUF_DMA_SG_H */
7a02264c PO	121