1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * generic helper functions for handling video4linux capture buffers 4 * 5 * (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org> 6 * 7 * Highly based on video-buf written originally by: 8 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> 9 * (c) 2006 Mauro Carvalho Chehab, <mchehab@kernel.org> 10 * (c) 2006 Ted Walther and John Sokol 11 */ 12 13 #ifndef _VIDEOBUF_CORE_H 14 #define _VIDEOBUF_CORE_H 15 16 #include <linux/poll.h> 17 #include <linux/videodev2.h> 18 19 #define UNSET (-1U) 20 21 22 struct videobuf_buffer; 23 struct videobuf_queue; 24 25 /* --------------------------------------------------------------------- */ 26 27 /* 28 * A small set of helper functions to manage video4linux buffers. 29 * 30 * struct videobuf_buffer holds the data structures used by the helper 31 * functions, additionally some commonly used fields for v4l buffers 32 * (width, height, lists, waitqueue) are in there. That struct should 33 * be used as first element in the drivers buffer struct. 34 * 35 * about the mmap helpers (videobuf_mmap_*): 36 * 37 * The mmaper function allows to map any subset of contiguous buffers. 38 * This includes one mmap() call for all buffers (which the original 39 * video4linux API uses) as well as one mmap() for every single buffer 40 * (which v4l2 uses). 41 * 42 * If there is a valid mapping for a buffer, buffer->baddr/bsize holds 43 * userspace address + size which can be fed into the 44 * videobuf_dma_init_user function listed above. 45 * 46 */ 47 48 struct videobuf_mapping { 49 unsigned int count; 50 struct videobuf_queue *q; 51 }; 52 53 enum videobuf_state { 54 VIDEOBUF_NEEDS_INIT = 0, 55 VIDEOBUF_PREPARED = 1, 56 VIDEOBUF_QUEUED = 2, 57 VIDEOBUF_ACTIVE = 3, 58 VIDEOBUF_DONE = 4, 59 VIDEOBUF_ERROR = 5, 60 VIDEOBUF_IDLE = 6, 61 }; 62 63 struct videobuf_buffer { 64 unsigned int i; 65 u32 magic; 66 67 /* info about the buffer */ 68 unsigned int width; 69 unsigned int height; 70 unsigned int bytesperline; /* use only if != 0 */ 71 unsigned long size; 72 enum v4l2_field field; 73 enum videobuf_state state; 74 struct list_head stream; /* QBUF/DQBUF list */ 75 76 /* touched by irq handler */ 77 struct list_head queue; 78 wait_queue_head_t done; 79 unsigned int field_count; 80 u64 ts; 81 82 /* Memory type */ 83 enum v4l2_memory memory; 84 85 /* buffer size */ 86 size_t bsize; 87 88 /* buffer offset (mmap + overlay) */ 89 size_t boff; 90 91 /* buffer addr (userland ptr!) */ 92 unsigned long baddr; 93 94 /* for mmap'ed buffers */ 95 struct videobuf_mapping *map; 96 97 /* Private pointer to allow specific methods to store their data */ 98 int privsize; 99 void *priv; 100 }; 101 102 struct videobuf_queue_ops { 103 int (*buf_setup)(struct videobuf_queue *q, 104 unsigned int *count, unsigned int *size); 105 int (*buf_prepare)(struct videobuf_queue *q, 106 struct videobuf_buffer *vb, 107 enum v4l2_field field); 108 void (*buf_queue)(struct videobuf_queue *q, 109 struct videobuf_buffer *vb); 110 void (*buf_release)(struct videobuf_queue *q, 111 struct videobuf_buffer *vb); 112 }; 113 114 #define MAGIC_QTYPE_OPS 0x12261003 115 116 /* Helper operations - device type dependent */ 117 struct videobuf_qtype_ops { 118 u32 magic; 119 120 struct videobuf_buffer *(*alloc_vb)(size_t size); 121 void *(*vaddr) (struct videobuf_buffer *buf); 122 int (*iolock) (struct videobuf_queue *q, 123 struct videobuf_buffer *vb, 124 struct v4l2_framebuffer *fbuf); 125 int (*sync) (struct videobuf_queue *q, 126 struct videobuf_buffer *buf); 127 int (*mmap_mapper) (struct videobuf_queue *q, 128 struct videobuf_buffer *buf, 129 struct vm_area_struct *vma); 130 }; 131 132 struct videobuf_queue { 133 struct mutex vb_lock; 134 struct mutex *ext_lock; 135 spinlock_t *irqlock; 136 struct device *dev; 137 138 wait_queue_head_t wait; /* wait if queue is empty */ 139 140 enum v4l2_buf_type type; 141 unsigned int msize; 142 enum v4l2_field field; 143 enum v4l2_field last; /* for field=V4L2_FIELD_ALTERNATE */ 144 struct videobuf_buffer *bufs[VIDEO_MAX_FRAME]; 145 const struct videobuf_queue_ops *ops; 146 struct videobuf_qtype_ops *int_ops; 147 148 unsigned int streaming:1; 149 unsigned int reading:1; 150 151 /* capture via mmap() + ioctl(QBUF/DQBUF) */ 152 struct list_head stream; 153 154 /* capture via read() */ 155 unsigned int read_off; 156 struct videobuf_buffer *read_buf; 157 158 /* driver private data */ 159 void *priv_data; 160 }; 161 162 static inline void videobuf_queue_lock(struct videobuf_queue *q) 163 { 164 if (!q->ext_lock) 165 mutex_lock(&q->vb_lock); 166 } 167 168 static inline void videobuf_queue_unlock(struct videobuf_queue *q) 169 { 170 if (!q->ext_lock) 171 mutex_unlock(&q->vb_lock); 172 } 173 174 int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb, 175 int non_blocking, int intr); 176 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb, 177 struct v4l2_framebuffer *fbuf); 178 179 struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q); 180 181 /* Used on videobuf-dvb */ 182 void *videobuf_queue_to_vaddr(struct videobuf_queue *q, 183 struct videobuf_buffer *buf); 184 185 void videobuf_queue_core_init(struct videobuf_queue *q, 186 const struct videobuf_queue_ops *ops, 187 struct device *dev, 188 spinlock_t *irqlock, 189 enum v4l2_buf_type type, 190 enum v4l2_field field, 191 unsigned int msize, 192 void *priv, 193 struct videobuf_qtype_ops *int_ops, 194 struct mutex *ext_lock); 195 int videobuf_queue_is_busy(struct videobuf_queue *q); 196 void videobuf_queue_cancel(struct videobuf_queue *q); 197 198 enum v4l2_field videobuf_next_field(struct videobuf_queue *q); 199 int videobuf_reqbufs(struct videobuf_queue *q, 200 struct v4l2_requestbuffers *req); 201 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b); 202 int videobuf_qbuf(struct videobuf_queue *q, 203 struct v4l2_buffer *b); 204 int videobuf_dqbuf(struct videobuf_queue *q, 205 struct v4l2_buffer *b, int nonblocking); 206 int videobuf_streamon(struct videobuf_queue *q); 207 int videobuf_streamoff(struct videobuf_queue *q); 208 209 void videobuf_stop(struct videobuf_queue *q); 210 211 int videobuf_read_start(struct videobuf_queue *q); 212 void videobuf_read_stop(struct videobuf_queue *q); 213 ssize_t videobuf_read_stream(struct videobuf_queue *q, 214 char __user *data, size_t count, loff_t *ppos, 215 int vbihack, int nonblocking); 216 ssize_t videobuf_read_one(struct videobuf_queue *q, 217 char __user *data, size_t count, loff_t *ppos, 218 int nonblocking); 219 __poll_t videobuf_poll_stream(struct file *file, 220 struct videobuf_queue *q, 221 poll_table *wait); 222 223 int videobuf_mmap_setup(struct videobuf_queue *q, 224 unsigned int bcount, unsigned int bsize, 225 enum v4l2_memory memory); 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_free(struct videobuf_queue *q); 230 int videobuf_mmap_mapper(struct videobuf_queue *q, 231 struct vm_area_struct *vma); 232 233 #endif 234