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 | * @flags: buffer flags as defined by &enum dmx_buffer_flags. |
89 | * Filled only at &DMX_DQBUF. &DMX_QBUF should zero this field. |
90 | * @count: monotonic counter for filled buffers. Helps to identify |
91 | * data stream loses. Filled only at &DMX_DQBUF. &DMX_QBUF should |
92 | * zero this field. |
93 | * |
94 | * @name: name of the device type. Currently, it can either be |
95 | * "dvr" or "demux_filter". |
96 | */ |
97 | struct dvb_vb2_ctx { |
98 | struct vb2_queue vb_q; |
99 | struct mutex mutex; |
100 | spinlock_t slock; |
101 | struct list_head dvb_q; |
102 | struct dvb_buffer *buf; |
103 | int offset; |
104 | int remain; |
105 | int state; |
106 | int buf_siz; |
107 | int buf_cnt; |
108 | int nonblocking; |
109 | |
110 | enum dmx_buffer_flags flags; |
111 | u32 count; |
112 | |
113 | char name[DVB_VB2_NAME_MAX + 1]; |
114 | }; |
115 | |
116 | #ifndef CONFIG_DVB_MMAP |
117 | static inline int dvb_vb2_init(struct dvb_vb2_ctx *ctx, |
118 | const char *name, int non_blocking) |
119 | { |
120 | return 0; |
121 | }; |
122 | static inline int dvb_vb2_release(struct dvb_vb2_ctx *ctx) |
123 | { |
124 | return 0; |
125 | }; |
126 | #define dvb_vb2_is_streaming(ctx) (0) |
127 | #define dvb_vb2_fill_buffer(ctx, file, wait, flags) (0) |
128 | |
129 | static inline __poll_t dvb_vb2_poll(struct dvb_vb2_ctx *ctx, |
130 | struct file *file, |
131 | poll_table *wait) |
132 | { |
133 | return 0; |
134 | } |
135 | #else |
136 | /** |
137 | * dvb_vb2_init - initializes VB2 handler |
138 | * |
139 | * @ctx: control struct for VB2 handler |
140 | * @name: name for the VB2 handler |
141 | * @non_blocking: |
142 | * if not zero, it means that the device is at non-blocking mode |
143 | */ |
144 | int dvb_vb2_init(struct dvb_vb2_ctx *ctx, const char *name, int non_blocking); |
145 | |
146 | /** |
147 | * dvb_vb2_release - Releases the VB2 handler allocated resources and |
148 | * put @ctx at DVB_VB2_STATE_NONE state. |
149 | * @ctx: control struct for VB2 handler |
150 | */ |
151 | int dvb_vb2_release(struct dvb_vb2_ctx *ctx); |
152 | |
153 | /** |
154 | * dvb_vb2_is_streaming - checks if the VB2 handler is streaming |
155 | * @ctx: control struct for VB2 handler |
156 | * |
157 | * Return: 0 if not streaming, 1 otherwise. |
158 | */ |
159 | int dvb_vb2_is_streaming(struct dvb_vb2_ctx *ctx); |
160 | |
161 | /** |
162 | * dvb_vb2_fill_buffer - fills a VB2 buffer |
163 | * @ctx: control struct for VB2 handler |
164 | * @src: place where the data is stored |
165 | * @len: number of bytes to be copied from @src |
166 | * @buffer_flags: |
167 | * pointer to buffer flags as defined by &enum dmx_buffer_flags. |
168 | * can be NULL. |
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 | |
174 | /** |
175 | * dvb_vb2_poll - Wrapper to vb2_core_streamon() for Digital TV |
176 | * buffer handling. |
177 | * |
178 | * @ctx: control struct for VB2 handler |
179 | * @file: &struct file argument passed to the poll |
180 | * file operation handler. |
181 | * @wait: &poll_table wait argument passed to the poll |
182 | * file operation handler. |
183 | * |
184 | * Implements poll syscall() logic. |
185 | */ |
186 | __poll_t dvb_vb2_poll(struct dvb_vb2_ctx *ctx, struct file *file, |
187 | poll_table *wait); |
188 | #endif |
189 | |
190 | /** |
191 | * dvb_vb2_stream_on() - Wrapper to vb2_core_streamon() for Digital TV |
192 | * buffer handling. |
193 | * |
194 | * @ctx: control struct for VB2 handler |
195 | * |
196 | * Starts dvb streaming |
197 | */ |
198 | int dvb_vb2_stream_on(struct dvb_vb2_ctx *ctx); |
199 | /** |
200 | * dvb_vb2_stream_off() - Wrapper to vb2_core_streamoff() for Digital TV |
201 | * buffer handling. |
202 | * |
203 | * @ctx: control struct for VB2 handler |
204 | * |
205 | * Stops dvb streaming |
206 | */ |
207 | int dvb_vb2_stream_off(struct dvb_vb2_ctx *ctx); |
208 | |
209 | /** |
210 | * dvb_vb2_reqbufs() - Wrapper to vb2_core_reqbufs() for Digital TV |
211 | * buffer handling. |
212 | * |
213 | * @ctx: control struct for VB2 handler |
214 | * @req: &struct dmx_requestbuffers passed from userspace in |
215 | * order to handle &DMX_REQBUFS. |
216 | * |
217 | * Initiate streaming by requesting a number of buffers. Also used to |
218 | * free previously requested buffers, is ``req->count`` is zero. |
219 | */ |
220 | int dvb_vb2_reqbufs(struct dvb_vb2_ctx *ctx, struct dmx_requestbuffers *req); |
221 | |
222 | /** |
223 | * dvb_vb2_querybuf() - Wrapper to vb2_core_querybuf() for Digital TV |
224 | * buffer handling. |
225 | * |
226 | * @ctx: control struct for VB2 handler |
227 | * @b: &struct dmx_buffer passed from userspace in |
228 | * order to handle &DMX_QUERYBUF. |
229 | * |
230 | * |
231 | */ |
232 | int dvb_vb2_querybuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b); |
233 | |
234 | /** |
235 | * dvb_vb2_expbuf() - Wrapper to vb2_core_expbuf() for Digital TV |
236 | * buffer handling. |
237 | * |
238 | * @ctx: control struct for VB2 handler |
239 | * @exp: &struct dmx_exportbuffer passed from userspace in |
240 | * order to handle &DMX_EXPBUF. |
241 | * |
242 | * Export a buffer as a file descriptor. |
243 | */ |
244 | int dvb_vb2_expbuf(struct dvb_vb2_ctx *ctx, struct dmx_exportbuffer *exp); |
245 | |
246 | /** |
247 | * dvb_vb2_qbuf() - Wrapper to vb2_core_qbuf() for Digital TV buffer handling. |
248 | * |
249 | * @ctx: control struct for VB2 handler |
250 | * @b: &struct dmx_buffer passed from userspace in |
251 | * order to handle &DMX_QBUF. |
252 | * |
253 | * Queue a Digital TV buffer as requested by userspace |
254 | */ |
255 | int dvb_vb2_qbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b); |
256 | |
257 | /** |
258 | * dvb_vb2_dqbuf() - Wrapper to vb2_core_dqbuf() for Digital TV |
259 | * buffer handling. |
260 | * |
261 | * @ctx: control struct for VB2 handler |
262 | * @b: &struct dmx_buffer passed from userspace in |
263 | * order to handle &DMX_DQBUF. |
264 | * |
265 | * Dequeue a Digital TV buffer to the userspace |
266 | */ |
267 | int dvb_vb2_dqbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b); |
268 | |
269 | /** |
270 | * dvb_vb2_mmap() - Wrapper to vb2_mmap() for Digital TV buffer handling. |
271 | * |
272 | * @ctx: control struct for VB2 handler |
273 | * @vma: pointer to &struct vm_area_struct with the vma passed |
274 | * to the mmap file operation handler in the driver. |
275 | * |
276 | * map Digital TV video buffers into application address space. |
277 | */ |
278 | int dvb_vb2_mmap(struct dvb_vb2_ctx *ctx, struct vm_area_struct *vma); |
279 | |
280 | #endif /* _DVB_VB2_H */ |
281 | |