1 /* 2 * helper functions for PCI DMA video4linux capture buffers 3 * 4 * The functions expect the hardware being able to scatter gatter 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 */ 20 21 #include <media/videobuf-core.h> 22 23 /* --------------------------------------------------------------------- */ 24 25 /* 26 * Return a scatterlist for some page-aligned vmalloc()'ed memory 27 * block (NULL on errors). Memory for the scatterlist is allocated 28 * using kmalloc. The caller must free the memory. 29 */ 30 struct scatterlist* videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages); 31 32 /* 33 * Return a scatterlist for a an array of userpages (NULL on errors). 34 * Memory for the scatterlist is allocated using kmalloc. The caller 35 * must free the memory. 36 */ 37 struct scatterlist* videobuf_pages_to_sg(struct page **pages, int nr_pages, 38 int offset); 39 40 /* --------------------------------------------------------------------- */ 41 42 /* 43 * A small set of helper functions to manage buffers (both userland 44 * and kernel) for DMA. 45 * 46 * videobuf_dma_init_*() 47 * creates a buffer. The userland version takes a userspace 48 * pointer + length. The kernel version just wants the size and 49 * does memory allocation too using vmalloc_32(). 50 * 51 * videobuf_dma_*() 52 * see Documentation/DMA-mapping.txt, these functions to 53 * basically the same. The map function does also build a 54 * scatterlist for the buffer (and unmap frees it ...) 55 * 56 * videobuf_dma_free() 57 * no comment ... 58 * 59 */ 60 61 struct videobuf_dmabuf { 62 u32 magic; 63 64 /* for userland buffer */ 65 int offset; 66 struct page **pages; 67 68 /* for kernel buffers */ 69 void *vmalloc; 70 71 /* Stores the userspace pointer to vmalloc area */ 72 void *varea; 73 74 /* for overlay buffers (pci-pci dma) */ 75 dma_addr_t bus_addr; 76 77 /* common */ 78 struct scatterlist *sglist; 79 int sglen; 80 int nr_pages; 81 int direction; 82 }; 83 84 struct videbuf_pci_sg_memory 85 { 86 u32 magic; 87 88 /* for mmap'ed buffers */ 89 struct videobuf_dmabuf dma; 90 }; 91 92 /* FIXME: To be removed soon */ 93 typedef int (vb_map_sg_t)(void *dev, struct scatterlist *sglist, int nr_pages, 94 int direction); 95 96 /* FIXME: To be removed soon */ 97 struct videobuf_dma_sg_ops 98 { 99 vb_map_sg_t *vb_map_sg; 100 vb_map_sg_t *vb_dma_sync_sg; 101 vb_map_sg_t *vb_unmap_sg; 102 103 }; 104 105 void videobuf_dma_init(struct videobuf_dmabuf *dma); 106 int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction, 107 unsigned long data, unsigned long size); 108 int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction, 109 int nr_pages); 110 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction, 111 dma_addr_t addr, int nr_pages); 112 int videobuf_dma_free(struct videobuf_dmabuf *dma); 113 114 int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma); 115 int videobuf_dma_sync(struct videobuf_queue* q,struct videobuf_dmabuf *dma); 116 int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma); 117 struct videobuf_dmabuf *videobuf_to_dma (struct videobuf_buffer *buf); 118 119 void *videobuf_pci_alloc (size_t size); 120 121 void videobuf_queue_pci_init(struct videobuf_queue* q, 122 struct videobuf_queue_ops *ops, 123 void *dev, 124 spinlock_t *irqlock, 125 enum v4l2_buf_type type, 126 enum v4l2_field field, 127 unsigned int msize, 128 void *priv); 129 130 /*FIXME: these variants are used only on *-alsa code, where videobuf is 131 * used without queue 132 */ 133 int videobuf_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma); 134 int videobuf_pci_dma_unmap(struct pci_dev *pci,struct videobuf_dmabuf *dma); 135 136 /* FIXME: temporary routine for vivi and tm6000, while lacking implementation 137 * of videobuf-vmalloc 138 */ 139 void videobuf_set_pci_ops (struct videobuf_queue* q, 140 struct videobuf_dma_sg_ops *ops); 141 142