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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: [email protected]
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 */
31enum 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 */
52enum 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 */
67struct 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 */
95struct 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
114static 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};
119static 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
126static 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 */
142int 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 */
150int 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 */
158int 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 */
170int 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 */
199int 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 */
208int 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 */
221int 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 */
233int 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 */
245int 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 */
256int 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 */
268int 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 */
279int dvb_vb2_mmap(struct dvb_vb2_ctx *ctx, struct vm_area_struct *vma);
280
281#endif /* _DVB_VB2_H */