38a54f35a0
The videobuf_queue_ops function vector is not declared constant, but there's no need for the videobuf layer to ever change it. Make it const so that videobuf users can make their operations const without warnings. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
120 lines
3.8 KiB
C
120 lines
3.8 KiB
C
/*
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* helper functions for SG DMA video4linux capture buffers
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*
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* The functions expect the hardware being able to scatter gather
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* (i.e. the buffers are not linear in physical memory, but fragmented
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* into PAGE_SIZE chunks). They also assume the driver does not need
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* to touch the video data.
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*
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* (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
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*
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* Highly based on video-buf written originally by:
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* (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
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* (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
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* (c) 2006 Ted Walther and John Sokol
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2
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*/
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#include <media/videobuf-core.h>
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/* --------------------------------------------------------------------- */
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/*
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* Return a scatterlist for some page-aligned vmalloc()'ed memory
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* block (NULL on errors). Memory for the scatterlist is allocated
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* using kmalloc. The caller must free the memory.
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*/
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struct scatterlist* videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages);
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/*
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* Return a scatterlist for a an array of userpages (NULL on errors).
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* Memory for the scatterlist is allocated using kmalloc. The caller
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* must free the memory.
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*/
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struct scatterlist* videobuf_pages_to_sg(struct page **pages, int nr_pages,
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int offset);
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/* --------------------------------------------------------------------- */
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/*
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* A small set of helper functions to manage buffers (both userland
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* and kernel) for DMA.
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*
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* videobuf_dma_init_*()
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* creates a buffer. The userland version takes a userspace
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* pointer + length. The kernel version just wants the size and
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* does memory allocation too using vmalloc_32().
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*
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* videobuf_dma_*()
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* see Documentation/PCI/PCI-DMA-mapping.txt, these functions to
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* basically the same. The map function does also build a
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* scatterlist for the buffer (and unmap frees it ...)
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*
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* videobuf_dma_free()
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* no comment ...
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*
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*/
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struct videobuf_dmabuf {
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u32 magic;
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/* for userland buffer */
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int offset;
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struct page **pages;
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/* for kernel buffers */
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void *vmalloc;
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/* for overlay buffers (pci-pci dma) */
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dma_addr_t bus_addr;
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/* common */
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struct scatterlist *sglist;
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int sglen;
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int nr_pages;
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int direction;
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};
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struct videobuf_dma_sg_memory
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{
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u32 magic;
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/* for mmap'ed buffers */
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struct videobuf_dmabuf dma;
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};
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void videobuf_dma_init(struct videobuf_dmabuf *dma);
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int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction,
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unsigned long data, unsigned long size);
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int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
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int nr_pages);
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int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
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dma_addr_t addr, int nr_pages);
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int videobuf_dma_free(struct videobuf_dmabuf *dma);
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int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
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int videobuf_dma_sync(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
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int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
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struct videobuf_dmabuf *videobuf_to_dma (struct videobuf_buffer *buf);
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void *videobuf_sg_alloc(size_t size);
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void videobuf_queue_sg_init(struct videobuf_queue* q,
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const struct videobuf_queue_ops *ops,
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struct device *dev,
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spinlock_t *irqlock,
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enum v4l2_buf_type type,
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enum v4l2_field field,
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unsigned int msize,
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void *priv);
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/*FIXME: these variants are used only on *-alsa code, where videobuf is
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* used without queue
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*/
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int videobuf_sg_dma_map(struct device *dev, struct videobuf_dmabuf *dma);
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int videobuf_sg_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma);
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