| /* |
| * 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> |
| |
| /* --------------------------------------------------------------------- */ |
| |
| /* |
| * 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; |
| size_t size; |
| struct page **pages; |
| |
| /* for kernel buffers */ |
| void *vaddr; |
| |
| /* 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. |
| */ |
| 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 device *dev, 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 */ |
| |