1 /* 2 * SPDX-License-Identifier: GPL-2.0 3 * 4 * dvb-vb2.h - DVB driver helper framework for streaming I/O 5 * 6 * Copyright (C) 2015 Samsung Electronics 7 * 8 * Author: jh1009.sung@samsung.com 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation. 13 */ 14 15 #ifndef _DVB_VB2_H 16 #define _DVB_VB2_H 17 18 #include <linux/mutex.h> 19 #include <linux/poll.h> 20 #include <linux/dvb/dmx.h> 21 #include <media/videobuf2-core.h> 22 #include <media/videobuf2-dma-contig.h> 23 #include <media/videobuf2-vmalloc.h> 24 25 /** 26 * enum dvb_buf_type - types of Digital TV memory-mapped buffers 27 * 28 * @DVB_BUF_TYPE_CAPTURE: buffer is filled by the Kernel, 29 * with a received Digital TV stream 30 */ 31 enum dvb_buf_type { 32 DVB_BUF_TYPE_CAPTURE = 1, 33 }; 34 35 /** 36 * enum dvb_vb2_states - states to control VB2 state machine 37 * @DVB_VB2_STATE_NONE: 38 * VB2 engine not initialized yet, init failed or VB2 was released. 39 * @DVB_VB2_STATE_INIT: 40 * VB2 engine initialized. 41 * @DVB_VB2_STATE_REQBUFS: 42 * Buffers were requested 43 * @DVB_VB2_STATE_STREAMON: 44 * VB2 is streaming. Callers should not check it directly. Instead, 45 * they should use dvb_vb2_is_streaming(). 46 * 47 * Note: 48 * 49 * Callers should not touch at the state machine directly. This 50 * is handled inside dvb_vb2.c. 51 */ 52 enum dvb_vb2_states { 53 DVB_VB2_STATE_NONE = 0x0, 54 DVB_VB2_STATE_INIT = 0x1, 55 DVB_VB2_STATE_REQBUFS = 0x2, 56 DVB_VB2_STATE_STREAMON = 0x4, 57 }; 58 59 #define DVB_VB2_NAME_MAX (20) 60 61 /** 62 * struct dvb_buffer - video buffer information for v4l2. 63 * 64 * @vb: embedded struct &vb2_buffer. 65 * @list: list of &struct dvb_buffer. 66 */ 67 struct dvb_buffer { 68 struct vb2_buffer vb; 69 struct list_head list; 70 }; 71 72 /** 73 * struct dvb_vb2_ctx - control struct for VB2 handler 74 * @vb_q: pointer to &struct vb2_queue with videobuf2 queue. 75 * @slock: spin lock used to protect buffer filling at dvb_vb2.c. 76 * @dvb_q: List of buffers that are not filled yet. 77 * @buf: Pointer to the buffer that are currently being filled. 78 * @offset: index to the next position at the @buf to be filled. 79 * @remain: How many bytes are left to be filled at @buf. 80 * @state: bitmask of buffer states as defined by &enum dvb_vb2_states. 81 * @buf_siz: size of each VB2 buffer. 82 * @buf_cnt: number of VB2 buffers. 83 * @nonblocking: 84 * If different than zero, device is operating on non-blocking 85 * mode. 86 * @flags: buffer flags as defined by &enum dmx_buffer_flags. 87 * Filled only at &DMX_DQBUF. &DMX_QBUF should zero this field. 88 * @count: monotonic counter for filled buffers. Helps to identify 89 * data stream loses. Filled only at &DMX_DQBUF. &DMX_QBUF should 90 * zero this field. 91 * 92 * @name: name of the device type. Currently, it can either be 93 * "dvr" or "demux_filter". 94 */ 95 struct dvb_vb2_ctx { 96 struct vb2_queue vb_q; 97 spinlock_t slock; 98 struct list_head dvb_q; 99 struct dvb_buffer *buf; 100 int offset; 101 int remain; 102 int state; 103 int buf_siz; 104 int buf_cnt; 105 int nonblocking; 106 107 enum dmx_buffer_flags flags; 108 u32 count; 109 110 char name[DVB_VB2_NAME_MAX + 1]; 111 }; 112 113 #ifndef CONFIG_DVB_MMAP 114 static inline int dvb_vb2_init(struct dvb_vb2_ctx *ctx, const char *name, 115 struct mutex *mutex, int non_blocking) 116 { 117 return 0; 118 }; 119 static inline int dvb_vb2_release(struct dvb_vb2_ctx *ctx) 120 { 121 return 0; 122 }; 123 #define dvb_vb2_is_streaming(ctx) (0) 124 #define dvb_vb2_fill_buffer(ctx, file, wait, flags, flush) (0) 125 126 static inline __poll_t dvb_vb2_poll(struct dvb_vb2_ctx *ctx, 127 struct file *file, 128 poll_table *wait) 129 { 130 return 0; 131 } 132 #else 133 /** 134 * dvb_vb2_init - initializes VB2 handler 135 * 136 * @ctx: control struct for VB2 handler 137 * @name: name for the VB2 handler 138 * @mutex: pointer to the mutex that serializes vb2 ioctls 139 * @non_blocking: 140 * if not zero, it means that the device is at non-blocking mode 141 */ 142 int dvb_vb2_init(struct dvb_vb2_ctx *ctx, const char *name, 143 struct mutex *mutex, int non_blocking); 144 145 /** 146 * dvb_vb2_release - Releases the VB2 handler allocated resources and 147 * put @ctx at DVB_VB2_STATE_NONE state. 148 * @ctx: control struct for VB2 handler 149 */ 150 int dvb_vb2_release(struct dvb_vb2_ctx *ctx); 151 152 /** 153 * dvb_vb2_is_streaming - checks if the VB2 handler is streaming 154 * @ctx: control struct for VB2 handler 155 * 156 * Return: 0 if not streaming, 1 otherwise. 157 */ 158 int dvb_vb2_is_streaming(struct dvb_vb2_ctx *ctx); 159 160 /** 161 * dvb_vb2_fill_buffer - fills a VB2 buffer 162 * @ctx: control struct for VB2 handler 163 * @src: place where the data is stored 164 * @len: number of bytes to be copied from @src 165 * @buffer_flags: 166 * pointer to buffer flags as defined by &enum dmx_buffer_flags. 167 * can be NULL. 168 * @flush: flush the buffer, even if it isn't full. 169 */ 170 int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx, 171 const unsigned char *src, int len, 172 enum dmx_buffer_flags *buffer_flags, 173 bool flush); 174 175 /** 176 * dvb_vb2_poll - Wrapper to vb2_core_streamon() for Digital TV 177 * buffer handling. 178 * 179 * @ctx: control struct for VB2 handler 180 * @file: &struct file argument passed to the poll 181 * file operation handler. 182 * @wait: &poll_table wait argument passed to the poll 183 * file operation handler. 184 * 185 * Implements poll syscall() logic. 186 */ 187 __poll_t dvb_vb2_poll(struct dvb_vb2_ctx *ctx, struct file *file, 188 poll_table *wait); 189 #endif 190 191 /** 192 * dvb_vb2_stream_on() - Wrapper to vb2_core_streamon() for Digital TV 193 * buffer handling. 194 * 195 * @ctx: control struct for VB2 handler 196 * 197 * Starts dvb streaming 198 */ 199 int dvb_vb2_stream_on(struct dvb_vb2_ctx *ctx); 200 /** 201 * dvb_vb2_stream_off() - Wrapper to vb2_core_streamoff() for Digital TV 202 * buffer handling. 203 * 204 * @ctx: control struct for VB2 handler 205 * 206 * Stops dvb streaming 207 */ 208 int dvb_vb2_stream_off(struct dvb_vb2_ctx *ctx); 209 210 /** 211 * dvb_vb2_reqbufs() - Wrapper to vb2_core_reqbufs() for Digital TV 212 * buffer handling. 213 * 214 * @ctx: control struct for VB2 handler 215 * @req: &struct dmx_requestbuffers passed from userspace in 216 * order to handle &DMX_REQBUFS. 217 * 218 * Initiate streaming by requesting a number of buffers. Also used to 219 * free previously requested buffers, is ``req->count`` is zero. 220 */ 221 int dvb_vb2_reqbufs(struct dvb_vb2_ctx *ctx, struct dmx_requestbuffers *req); 222 223 /** 224 * dvb_vb2_querybuf() - Wrapper to vb2_core_querybuf() for Digital TV 225 * buffer handling. 226 * 227 * @ctx: control struct for VB2 handler 228 * @b: &struct dmx_buffer passed from userspace in 229 * order to handle &DMX_QUERYBUF. 230 * 231 * 232 */ 233 int dvb_vb2_querybuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b); 234 235 /** 236 * dvb_vb2_expbuf() - Wrapper to vb2_core_expbuf() for Digital TV 237 * buffer handling. 238 * 239 * @ctx: control struct for VB2 handler 240 * @exp: &struct dmx_exportbuffer passed from userspace in 241 * order to handle &DMX_EXPBUF. 242 * 243 * Export a buffer as a file descriptor. 244 */ 245 int dvb_vb2_expbuf(struct dvb_vb2_ctx *ctx, struct dmx_exportbuffer *exp); 246 247 /** 248 * dvb_vb2_qbuf() - Wrapper to vb2_core_qbuf() for Digital TV buffer handling. 249 * 250 * @ctx: control struct for VB2 handler 251 * @b: &struct dmx_buffer passed from userspace in 252 * order to handle &DMX_QBUF. 253 * 254 * Queue a Digital TV buffer as requested by userspace 255 */ 256 int dvb_vb2_qbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b); 257 258 /** 259 * dvb_vb2_dqbuf() - Wrapper to vb2_core_dqbuf() for Digital TV 260 * buffer handling. 261 * 262 * @ctx: control struct for VB2 handler 263 * @b: &struct dmx_buffer passed from userspace in 264 * order to handle &DMX_DQBUF. 265 * 266 * Dequeue a Digital TV buffer to the userspace 267 */ 268 int dvb_vb2_dqbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b); 269 270 /** 271 * dvb_vb2_mmap() - Wrapper to vb2_mmap() for Digital TV buffer handling. 272 * 273 * @ctx: control struct for VB2 handler 274 * @vma: pointer to &struct vm_area_struct with the vma passed 275 * to the mmap file operation handler in the driver. 276 * 277 * map Digital TV video buffers into application address space. 278 */ 279 int dvb_vb2_mmap(struct dvb_vb2_ctx *ctx, struct vm_area_struct *vma); 280 281 #endif /* _DVB_VB2_H */ 282