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 * @mutex: mutex to serialize vb2 operations. Used by 76 * vb2 core %wait_prepare and %wait_finish operations. 77 * @slock: spin lock used to protect buffer filling at dvb_vb2.c. 78 * @dvb_q: List of buffers that are not filled yet. 79 * @buf: Pointer to the buffer that are currently being filled. 80 * @offset: index to the next position at the @buf to be filled. 81 * @remain: How many bytes are left to be filled at @buf. 82 * @state: bitmask of buffer states as defined by &enum dvb_vb2_states. 83 * @buf_siz: size of each VB2 buffer. 84 * @buf_cnt: number of VB2 buffers. 85 * @nonblocking: 86 * If different than zero, device is operating on non-blocking 87 * mode. 88 * @name: name of the device type. Currently, it can either be 89 * "dvr" or "demux_filter". 90 */ 91 struct dvb_vb2_ctx { 92 struct vb2_queue vb_q; 93 struct mutex mutex; 94 spinlock_t slock; 95 struct list_head dvb_q; 96 struct dvb_buffer *buf; 97 int offset; 98 int remain; 99 int state; 100 int buf_siz; 101 int buf_cnt; 102 int nonblocking; 103 char name[DVB_VB2_NAME_MAX + 1]; 104 }; 105 106 #ifndef DVB_MMAP 107 static inline int dvb_vb2_init(struct dvb_vb2_ctx *ctx, 108 const char *name, int non_blocking) 109 { 110 return 0; 111 }; 112 static inline int dvb_vb2_release(struct dvb_vb2_ctx *ctx) 113 { 114 return 0; 115 }; 116 #define dvb_vb2_is_streaming(ctx) (0) 117 #define dvb_vb2_fill_buffer(ctx, file, wait) (0) 118 119 static inline __poll_t dvb_vb2_poll(struct dvb_vb2_ctx *ctx, 120 struct file *file, 121 poll_table *wait) 122 { 123 return 0; 124 } 125 #else 126 /** 127 * dvb_vb2_init - initializes VB2 handler 128 * 129 * @ctx: control struct for VB2 handler 130 * @name: name for the VB2 handler 131 * @non_blocking: 132 * if not zero, it means that the device is at non-blocking mode 133 */ 134 int dvb_vb2_init(struct dvb_vb2_ctx *ctx, const char *name, int non_blocking); 135 136 /** 137 * dvb_vb2_release - Releases the VB2 handler allocated resources and 138 * put @ctx at DVB_VB2_STATE_NONE state. 139 * @ctx: control struct for VB2 handler 140 */ 141 int dvb_vb2_release(struct dvb_vb2_ctx *ctx); 142 143 /** 144 * dvb_vb2_is_streaming - checks if the VB2 handler is streaming 145 * @ctx: control struct for VB2 handler 146 * 147 * Return: 0 if not streaming, 1 otherwise. 148 */ 149 int dvb_vb2_is_streaming(struct dvb_vb2_ctx *ctx); 150 151 /** 152 * dvb_vb2_fill_buffer - fills a VB2 buffer 153 * @ctx: control struct for VB2 handler 154 * @src: place where the data is stored 155 * @len: number of bytes to be copied from @src 156 */ 157 int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx, 158 const unsigned char *src, int len); 159 160 /** 161 * dvb_vb2_poll - Wrapper to vb2_core_streamon() for Digital TV 162 * buffer handling. 163 * 164 * @ctx: control struct for VB2 handler 165 * @file: &struct file argument passed to the poll 166 * file operation handler. 167 * @wait: &poll_table wait argument passed to the poll 168 * file operation handler. 169 * 170 * Implements poll syscall() logic. 171 */ 172 __poll_t dvb_vb2_poll(struct dvb_vb2_ctx *ctx, struct file *file, 173 poll_table *wait); 174 #endif 175 176 /** 177 * dvb_vb2_stream_on() - Wrapper to vb2_core_streamon() for Digital TV 178 * buffer handling. 179 * 180 * @ctx: control struct for VB2 handler 181 * 182 * Starts dvb streaming 183 */ 184 int dvb_vb2_stream_on(struct dvb_vb2_ctx *ctx); 185 /** 186 * dvb_vb2_stream_off() - Wrapper to vb2_core_streamoff() for Digital TV 187 * buffer handling. 188 * 189 * @ctx: control struct for VB2 handler 190 * 191 * Stops dvb streaming 192 */ 193 int dvb_vb2_stream_off(struct dvb_vb2_ctx *ctx); 194 195 /** 196 * dvb_vb2_reqbufs() - Wrapper to vb2_core_reqbufs() for Digital TV 197 * buffer handling. 198 * 199 * @ctx: control struct for VB2 handler 200 * @req: &struct dmx_requestbuffers passed from userspace in 201 * order to handle &DMX_REQBUFS. 202 * 203 * Initiate streaming by requesting a number of buffers. Also used to 204 * free previously requested buffers, is ``req->count`` is zero. 205 */ 206 int dvb_vb2_reqbufs(struct dvb_vb2_ctx *ctx, struct dmx_requestbuffers *req); 207 208 /** 209 * dvb_vb2_querybuf() - Wrapper to vb2_core_querybuf() for Digital TV 210 * buffer handling. 211 * 212 * @ctx: control struct for VB2 handler 213 * @b: &struct dmx_buffer passed from userspace in 214 * order to handle &DMX_QUERYBUF. 215 * 216 * 217 */ 218 int dvb_vb2_querybuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b); 219 220 /** 221 * dvb_vb2_expbuf() - Wrapper to vb2_core_expbuf() for Digital TV 222 * buffer handling. 223 * 224 * @ctx: control struct for VB2 handler 225 * @exp: &struct dmx_exportbuffer passed from userspace in 226 * order to handle &DMX_EXPBUF. 227 * 228 * Export a buffer as a file descriptor. 229 */ 230 int dvb_vb2_expbuf(struct dvb_vb2_ctx *ctx, struct dmx_exportbuffer *exp); 231 232 /** 233 * dvb_vb2_qbuf() - Wrapper to vb2_core_qbuf() for Digital TV buffer handling. 234 * 235 * @ctx: control struct for VB2 handler 236 * @b: &struct dmx_buffer passed from userspace in 237 * order to handle &DMX_QBUF. 238 * 239 * Queue a Digital TV buffer as requested by userspace 240 */ 241 int dvb_vb2_qbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b); 242 243 /** 244 * dvb_vb2_dqbuf() - Wrapper to vb2_core_dqbuf() for Digital TV 245 * buffer handling. 246 * 247 * @ctx: control struct for VB2 handler 248 * @b: &struct dmx_buffer passed from userspace in 249 * order to handle &DMX_DQBUF. 250 * 251 * Dequeue a Digital TV buffer to the userspace 252 */ 253 int dvb_vb2_dqbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b); 254 255 /** 256 * dvb_vb2_mmap() - Wrapper to vb2_mmap() for Digital TV buffer handling. 257 * 258 * @ctx: control struct for VB2 handler 259 * @vma: pointer to &struct vm_area_struct with the vma passed 260 * to the mmap file operation handler in the driver. 261 * 262 * map Digital TV video buffers into application address space. 263 */ 264 int dvb_vb2_mmap(struct dvb_vb2_ctx *ctx, struct vm_area_struct *vma); 265 266 #endif /* _DVB_VB2_H */ 267