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 */