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Diffstat (limited to 'include/media/videobuf-dma-sg.h')
| -rw-r--r-- | include/media/videobuf-dma-sg.h | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/include/media/videobuf-dma-sg.h b/include/media/videobuf-dma-sg.h new file mode 100644 index 000000000000..62a3709905f3 --- /dev/null +++ b/include/media/videobuf-dma-sg.h @@ -0,0 +1,142 @@ +/* + * helper functions for PCI DMA video4linux capture buffers + * + * The functions expect the hardware being able to scatter gatter + * (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 + */ + +#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/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; + + /* Stores the userspace pointer to vmalloc area */ + void *varea; + + /* for overlay buffers (pci-pci dma) */ + dma_addr_t bus_addr; + + /* common */ + struct scatterlist *sglist; + int sglen; + int nr_pages; + int direction; +}; + +struct videbuf_pci_sg_memory +{ + u32 magic; + + /* for mmap'ed buffers */ + struct videobuf_mapping *map; + struct videobuf_dmabuf dma; +}; + +/* FIXME: To be removed soon */ +typedef int (vb_map_sg_t)(void *dev, struct scatterlist *sglist, int nr_pages, + int direction); + +/* FIXME: To be removed soon */ +struct videobuf_dma_sg_ops +{ + vb_map_sg_t *vb_map_sg; + vb_map_sg_t *vb_dma_sync_sg; + vb_map_sg_t *vb_unmap_sg; + +}; + +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_sync(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_pci_alloc (size_t size); + +void videobuf_queue_pci_init(struct videobuf_queue* q, + struct videobuf_queue_ops *ops, + void *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_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma); +int videobuf_pci_dma_unmap(struct pci_dev *pci,struct videobuf_dmabuf *dma); + +/* FIXME: temporary routine for vivi and tm6000, while lacking implementation + * of videobuf-vmalloc + */ +void videobuf_set_pci_ops (struct videobuf_queue* q, + struct videobuf_dma_sg_ops *ops); + |