dvb_vb2.h

  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 */
 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 * @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 */
 97struct 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
117static inline int dvb_vb2_init(struct dvb_vb2_ctx *ctx,
118			       const char *name, int non_blocking)
119{
120	return 0;
121};
122static 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, flush) (0)
128
129static 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 */
144int 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 */
151int 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 */
159int 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 * @flush:	flush the buffer, even if it isn't full.
170 */
171int dvb_vb2_fill_buffer(struct dvb_vb2_ctx *ctx,
172			const unsigned char *src, int len,
173			enum dmx_buffer_flags *buffer_flags,
174			bool flush);
175
176/**
177 * dvb_vb2_poll - Wrapper to vb2_core_streamon() for Digital TV
178 *      buffer handling.
179 *
180 * @ctx:	control struct for VB2 handler
181 * @file:	&struct file argument passed to the poll
182 *		file operation handler.
183 * @wait:	&poll_table wait argument passed to the poll
184 *		file operation handler.
185 *
186 * Implements poll syscall() logic.
187 */
188__poll_t dvb_vb2_poll(struct dvb_vb2_ctx *ctx, struct file *file,
189		      poll_table *wait);
190#endif
191
192/**
193 * dvb_vb2_stream_on() - Wrapper to vb2_core_streamon() for Digital TV
194 *	buffer handling.
195 *
196 * @ctx:	control struct for VB2 handler
197 *
198 * Starts dvb streaming
199 */
200int dvb_vb2_stream_on(struct dvb_vb2_ctx *ctx);
201/**
202 * dvb_vb2_stream_off() - Wrapper to vb2_core_streamoff() for Digital TV
203 *	buffer handling.
204 *
205 * @ctx:	control struct for VB2 handler
206 *
207 * Stops dvb streaming
208 */
209int dvb_vb2_stream_off(struct dvb_vb2_ctx *ctx);
210
211/**
212 * dvb_vb2_reqbufs() - Wrapper to vb2_core_reqbufs() for Digital TV
213 *	buffer handling.
214 *
215 * @ctx:	control struct for VB2 handler
216 * @req:	&struct dmx_requestbuffers passed from userspace in
217 *		order to handle &DMX_REQBUFS.
218 *
219 * Initiate streaming by requesting a number of buffers. Also used to
220 * free previously requested buffers, is ``req->count`` is zero.
221 */
222int dvb_vb2_reqbufs(struct dvb_vb2_ctx *ctx, struct dmx_requestbuffers *req);
223
224/**
225 * dvb_vb2_querybuf() - Wrapper to vb2_core_querybuf() for Digital TV
226 *	buffer handling.
227 *
228 * @ctx:	control struct for VB2 handler
229 * @b:		&struct dmx_buffer passed from userspace in
230 *		order to handle &DMX_QUERYBUF.
231 *
232 *
233 */
234int dvb_vb2_querybuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b);
235
236/**
237 * dvb_vb2_expbuf() - Wrapper to vb2_core_expbuf() for Digital TV
238 *	buffer handling.
239 *
240 * @ctx:	control struct for VB2 handler
241 * @exp:	&struct dmx_exportbuffer passed from userspace in
242 *		order to handle &DMX_EXPBUF.
243 *
244 * Export a buffer as a file descriptor.
245 */
246int dvb_vb2_expbuf(struct dvb_vb2_ctx *ctx, struct dmx_exportbuffer *exp);
247
248/**
249 * dvb_vb2_qbuf() - Wrapper to vb2_core_qbuf() for Digital TV buffer handling.
250 *
251 * @ctx:	control struct for VB2 handler
252 * @b:		&struct dmx_buffer passed from userspace in
253 *		order to handle &DMX_QBUF.
254 *
255 * Queue a Digital TV buffer as requested by userspace
256 */
257int dvb_vb2_qbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b);
258
259/**
260 * dvb_vb2_dqbuf() - Wrapper to vb2_core_dqbuf() for Digital TV
261 *	buffer handling.
262 *
263 * @ctx:	control struct for VB2 handler
264 * @b:		&struct dmx_buffer passed from userspace in
265 *		order to handle &DMX_DQBUF.
266 *
267 * Dequeue a Digital TV buffer to the userspace
268 */
269int dvb_vb2_dqbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b);
270
271/**
272 * dvb_vb2_mmap() - Wrapper to vb2_mmap() for Digital TV buffer handling.
273 *
274 * @ctx:	control struct for VB2 handler
275 * @vma:        pointer to &struct vm_area_struct with the vma passed
276 *              to the mmap file operation handler in the driver.
277 *
278 * map Digital TV video buffers into application address space.
279 */
280int dvb_vb2_mmap(struct dvb_vb2_ctx *ctx, struct vm_area_struct *vma);
281
282#endif /* _DVB_VB2_H */