1 /* 2 * generic helper functions for handling video4linux capture buffers 3 * 4 * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org> 5 * 6 * Highly based on video-buf written originally by: 7 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> 8 * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org> 9 * (c) 2006 Ted Walther and John Sokol 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 14 */ 15 16 #ifndef _VIDEOBUF_CORE_H 17 #define _VIDEOBUF_CORE_H 18 19 #include <linux/poll.h> 20 #include <linux/videodev2.h> 21 22 #define UNSET (-1U) 23 24 25 struct videobuf_buffer; 26 struct videobuf_queue; 27 28 /* --------------------------------------------------------------------- */ 29 30 /* 31 * A small set of helper functions to manage video4linux buffers. 32 * 33 * struct videobuf_buffer holds the data structures used by the helper 34 * functions, additionally some commonly used fields for v4l buffers 35 * (width, height, lists, waitqueue) are in there. That struct should 36 * be used as first element in the drivers buffer struct. 37 * 38 * about the mmap helpers (videobuf_mmap_*): 39 * 40 * The mmaper function allows to map any subset of contiguous buffers. 41 * This includes one mmap() call for all buffers (which the original 42 * video4linux API uses) as well as one mmap() for every single buffer 43 * (which v4l2 uses). 44 * 45 * If there is a valid mapping for a buffer, buffer->baddr/bsize holds 46 * userspace address + size which can be feeded into the 47 * videobuf_dma_init_user function listed above. 48 * 49 */ 50 51 struct videobuf_mapping { 52 unsigned int count; 53 struct videobuf_queue *q; 54 }; 55 56 enum videobuf_state { 57 VIDEOBUF_NEEDS_INIT = 0, 58 VIDEOBUF_PREPARED = 1, 59 VIDEOBUF_QUEUED = 2, 60 VIDEOBUF_ACTIVE = 3, 61 VIDEOBUF_DONE = 4, 62 VIDEOBUF_ERROR = 5, 63 VIDEOBUF_IDLE = 6, 64 }; 65 66 struct videobuf_buffer { 67 unsigned int i; 68 u32 magic; 69 70 /* info about the buffer */ 71 unsigned int width; 72 unsigned int height; 73 unsigned int bytesperline; /* use only if != 0 */ 74 unsigned long size; 75 enum v4l2_field field; 76 enum videobuf_state state; 77 struct list_head stream; /* QBUF/DQBUF list */ 78 79 /* touched by irq handler */ 80 struct list_head queue; 81 wait_queue_head_t done; 82 unsigned int field_count; 83 struct timeval ts; 84 85 /* Memory type */ 86 enum v4l2_memory memory; 87 88 /* buffer size */ 89 size_t bsize; 90 91 /* buffer offset (mmap + overlay) */ 92 size_t boff; 93 94 /* buffer addr (userland ptr!) */ 95 unsigned long baddr; 96 97 /* for mmap'ed buffers */ 98 struct videobuf_mapping *map; 99 100 /* Private pointer to allow specific methods to store their data */ 101 int privsize; 102 void *priv; 103 }; 104 105 struct videobuf_queue_ops { 106 int (*buf_setup)(struct videobuf_queue *q, 107 unsigned int *count, unsigned int *size); 108 int (*buf_prepare)(struct videobuf_queue *q, 109 struct videobuf_buffer *vb, 110 enum v4l2_field field); 111 void (*buf_queue)(struct videobuf_queue *q, 112 struct videobuf_buffer *vb); 113 void (*buf_release)(struct videobuf_queue *q, 114 struct videobuf_buffer *vb); 115 }; 116 117 #define MAGIC_QTYPE_OPS 0x12261003 118 119 /* Helper operations - device type dependent */ 120 struct videobuf_qtype_ops { 121 u32 magic; 122 123 struct videobuf_buffer *(*alloc_vb)(size_t size); 124 void *(*vaddr) (struct videobuf_buffer *buf); 125 int (*iolock) (struct videobuf_queue *q, 126 struct videobuf_buffer *vb, 127 struct v4l2_framebuffer *fbuf); 128 int (*sync) (struct videobuf_queue *q, 129 struct videobuf_buffer *buf); 130 int (*mmap_mapper) (struct videobuf_queue *q, 131 struct videobuf_buffer *buf, 132 struct vm_area_struct *vma); 133 }; 134 135 struct videobuf_queue { 136 struct mutex vb_lock; 137 struct mutex *ext_lock; 138 spinlock_t *irqlock; 139 struct device *dev; 140 141 wait_queue_head_t wait; /* wait if queue is empty */ 142 143 enum v4l2_buf_type type; 144 unsigned int msize; 145 enum v4l2_field field; 146 enum v4l2_field last; /* for field=V4L2_FIELD_ALTERNATE */ 147 struct videobuf_buffer *bufs[VIDEO_MAX_FRAME]; 148 const struct videobuf_queue_ops *ops; 149 struct videobuf_qtype_ops *int_ops; 150 151 unsigned int streaming:1; 152 unsigned int reading:1; 153 154 /* capture via mmap() + ioctl(QBUF/DQBUF) */ 155 struct list_head stream; 156 157 /* capture via read() */ 158 unsigned int read_off; 159 struct videobuf_buffer *read_buf; 160 161 /* driver private data */ 162 void *priv_data; 163 }; 164 165 static inline void videobuf_queue_lock(struct videobuf_queue *q) 166 { 167 if (!q->ext_lock) 168 mutex_lock(&q->vb_lock); 169 } 170 171 static inline void videobuf_queue_unlock(struct videobuf_queue *q) 172 { 173 if (!q->ext_lock) 174 mutex_unlock(&q->vb_lock); 175 } 176 177 int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb, 178 int non_blocking, int intr); 179 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb, 180 struct v4l2_framebuffer *fbuf); 181 182 struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q); 183 184 /* Used on videobuf-dvb */ 185 void *videobuf_queue_to_vaddr(struct videobuf_queue *q, 186 struct videobuf_buffer *buf); 187 188 void videobuf_queue_core_init(struct videobuf_queue *q, 189 const struct videobuf_queue_ops *ops, 190 struct device *dev, 191 spinlock_t *irqlock, 192 enum v4l2_buf_type type, 193 enum v4l2_field field, 194 unsigned int msize, 195 void *priv, 196 struct videobuf_qtype_ops *int_ops, 197 struct mutex *ext_lock); 198 int videobuf_queue_is_busy(struct videobuf_queue *q); 199 void videobuf_queue_cancel(struct videobuf_queue *q); 200 201 enum v4l2_field videobuf_next_field(struct videobuf_queue *q); 202 int videobuf_reqbufs(struct videobuf_queue *q, 203 struct v4l2_requestbuffers *req); 204 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b); 205 int videobuf_qbuf(struct videobuf_queue *q, 206 struct v4l2_buffer *b); 207 int videobuf_dqbuf(struct videobuf_queue *q, 208 struct v4l2_buffer *b, int nonblocking); 209 int videobuf_streamon(struct videobuf_queue *q); 210 int videobuf_streamoff(struct videobuf_queue *q); 211 212 void videobuf_stop(struct videobuf_queue *q); 213 214 int videobuf_read_start(struct videobuf_queue *q); 215 void videobuf_read_stop(struct videobuf_queue *q); 216 ssize_t videobuf_read_stream(struct videobuf_queue *q, 217 char __user *data, size_t count, loff_t *ppos, 218 int vbihack, int nonblocking); 219 ssize_t videobuf_read_one(struct videobuf_queue *q, 220 char __user *data, size_t count, loff_t *ppos, 221 int nonblocking); 222 unsigned int videobuf_poll_stream(struct file *file, 223 struct videobuf_queue *q, 224 poll_table *wait); 225 226 int videobuf_mmap_setup(struct videobuf_queue *q, 227 unsigned int bcount, unsigned int bsize, 228 enum v4l2_memory memory); 229 int __videobuf_mmap_setup(struct videobuf_queue *q, 230 unsigned int bcount, unsigned int bsize, 231 enum v4l2_memory memory); 232 int videobuf_mmap_free(struct videobuf_queue *q); 233 int videobuf_mmap_mapper(struct videobuf_queue *q, 234 struct vm_area_struct *vma); 235 236 #endif 237