xref: /openbmc/linux/include/media/v4l2-mem2mem.h (revision eb3fcf00)
1 /*
2  * Memory-to-memory device framework for Video for Linux 2.
3  *
4  * Helper functions for devices that use memory buffers for both source
5  * and destination.
6  *
7  * Copyright (c) 2009 Samsung Electronics Co., Ltd.
8  * Pawel Osciak, <pawel@osciak.com>
9  * Marek Szyprowski, <m.szyprowski@samsung.com>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by the
13  * Free Software Foundation; either version 2 of the
14  * License, or (at your option) any later version
15  */
16 
17 #ifndef _MEDIA_V4L2_MEM2MEM_H
18 #define _MEDIA_V4L2_MEM2MEM_H
19 
20 #include <media/videobuf2-core.h>
21 
22 /**
23  * struct v4l2_m2m_ops - mem-to-mem device driver callbacks
24  * @device_run:	required. Begin the actual job (transaction) inside this
25  *		callback.
26  *		The job does NOT have to end before this callback returns
27  *		(and it will be the usual case). When the job finishes,
28  *		v4l2_m2m_job_finish() has to be called.
29  * @job_ready:	optional. Should return 0 if the driver does not have a job
30  *		fully prepared to run yet (i.e. it will not be able to finish a
31  *		transaction without sleeping). If not provided, it will be
32  *		assumed that one source and one destination buffer are all
33  *		that is required for the driver to perform one full transaction.
34  *		This method may not sleep.
35  * @job_abort:	required. Informs the driver that it has to abort the currently
36  *		running transaction as soon as possible (i.e. as soon as it can
37  *		stop the device safely; e.g. in the next interrupt handler),
38  *		even if the transaction would not have been finished by then.
39  *		After the driver performs the necessary steps, it has to call
40  *		v4l2_m2m_job_finish() (as if the transaction ended normally).
41  *		This function does not have to (and will usually not) wait
42  *		until the device enters a state when it can be stopped.
43  * @lock:	optional. Define a driver's own lock callback, instead of using
44  *		m2m_ctx->q_lock.
45  * @unlock:	optional. Define a driver's own unlock callback, instead of
46  *		using m2m_ctx->q_lock.
47  */
48 struct v4l2_m2m_ops {
49 	void (*device_run)(void *priv);
50 	int (*job_ready)(void *priv);
51 	void (*job_abort)(void *priv);
52 	void (*lock)(void *priv);
53 	void (*unlock)(void *priv);
54 };
55 
56 struct v4l2_m2m_dev;
57 
58 struct v4l2_m2m_queue_ctx {
59 /* private: internal use only */
60 	struct vb2_queue	q;
61 
62 	/* Queue for buffers ready to be processed as soon as this
63 	 * instance receives access to the device */
64 	struct list_head	rdy_queue;
65 	spinlock_t		rdy_spinlock;
66 	u8			num_rdy;
67 	bool			buffered;
68 };
69 
70 struct v4l2_m2m_ctx {
71 	/* optional cap/out vb2 queues lock */
72 	struct mutex			*q_lock;
73 
74 /* private: internal use only */
75 	struct v4l2_m2m_dev		*m2m_dev;
76 
77 	/* Capture (output to memory) queue context */
78 	struct v4l2_m2m_queue_ctx	cap_q_ctx;
79 
80 	/* Output (input from memory) queue context */
81 	struct v4l2_m2m_queue_ctx	out_q_ctx;
82 
83 	/* For device job queue */
84 	struct list_head		queue;
85 	unsigned long			job_flags;
86 	wait_queue_head_t		finished;
87 
88 	/* Instance private data */
89 	void				*priv;
90 };
91 
92 struct v4l2_m2m_buffer {
93 	struct vb2_buffer	vb;
94 	struct list_head	list;
95 };
96 
97 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev);
98 
99 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
100 				       enum v4l2_buf_type type);
101 
102 void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx);
103 
104 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
105 			 struct v4l2_m2m_ctx *m2m_ctx);
106 
107 static inline void
108 v4l2_m2m_buf_done(struct vb2_buffer *buf, enum vb2_buffer_state state)
109 {
110 	vb2_buffer_done(buf, state);
111 }
112 
113 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
114 		     struct v4l2_requestbuffers *reqbufs);
115 
116 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
117 		      struct v4l2_buffer *buf);
118 
119 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
120 		  struct v4l2_buffer *buf);
121 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
122 		   struct v4l2_buffer *buf);
123 int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
124 			 struct v4l2_buffer *buf);
125 int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
126 			 struct v4l2_create_buffers *create);
127 
128 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
129 		   struct v4l2_exportbuffer *eb);
130 
131 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
132 		      enum v4l2_buf_type type);
133 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
134 		       enum v4l2_buf_type type);
135 
136 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
137 			   struct poll_table_struct *wait);
138 
139 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
140 		  struct vm_area_struct *vma);
141 
142 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops);
143 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev);
144 
145 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
146 		void *drv_priv,
147 		int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq));
148 
149 static inline void v4l2_m2m_set_src_buffered(struct v4l2_m2m_ctx *m2m_ctx,
150 					     bool buffered)
151 {
152 	m2m_ctx->out_q_ctx.buffered = buffered;
153 }
154 
155 static inline void v4l2_m2m_set_dst_buffered(struct v4l2_m2m_ctx *m2m_ctx,
156 					     bool buffered)
157 {
158 	m2m_ctx->cap_q_ctx.buffered = buffered;
159 }
160 
161 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx);
162 
163 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb);
164 
165 /**
166  * v4l2_m2m_num_src_bufs_ready() - return the number of source buffers ready for
167  * use
168  *
169  * @m2m_ctx: pointer to struct v4l2_m2m_ctx
170  */
171 static inline
172 unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
173 {
174 	return m2m_ctx->out_q_ctx.num_rdy;
175 }
176 
177 /**
178  * v4l2_m2m_num_src_bufs_ready() - return the number of destination buffers
179  * ready for use
180  *
181  * @m2m_ctx: pointer to struct v4l2_m2m_ctx
182  */
183 static inline
184 unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
185 {
186 	return m2m_ctx->cap_q_ctx.num_rdy;
187 }
188 
189 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx);
190 
191 /**
192  * v4l2_m2m_next_src_buf() - return next source buffer from the list of ready
193  * buffers
194  *
195  * @m2m_ctx: pointer to struct v4l2_m2m_ctx
196  */
197 static inline void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
198 {
199 	return v4l2_m2m_next_buf(&m2m_ctx->out_q_ctx);
200 }
201 
202 /**
203  * v4l2_m2m_next_dst_buf() - return next destination buffer from the list of
204  * ready buffers
205  *
206  * @m2m_ctx: pointer to struct v4l2_m2m_ctx
207  */
208 static inline void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
209 {
210 	return v4l2_m2m_next_buf(&m2m_ctx->cap_q_ctx);
211 }
212 
213 /**
214  * v4l2_m2m_get_src_vq() - return vb2_queue for source buffers
215  *
216  * @m2m_ctx: pointer to struct v4l2_m2m_ctx
217  */
218 static inline
219 struct vb2_queue *v4l2_m2m_get_src_vq(struct v4l2_m2m_ctx *m2m_ctx)
220 {
221 	return &m2m_ctx->out_q_ctx.q;
222 }
223 
224 /**
225  * v4l2_m2m_get_dst_vq() - return vb2_queue for destination buffers
226  *
227  * @m2m_ctx: pointer to struct v4l2_m2m_ctx
228  */
229 static inline
230 struct vb2_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx)
231 {
232 	return &m2m_ctx->cap_q_ctx.q;
233 }
234 
235 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx);
236 
237 /**
238  * v4l2_m2m_src_buf_remove() - take off a source buffer from the list of ready
239  * buffers and return it
240  *
241  * @m2m_ctx: pointer to struct v4l2_m2m_ctx
242  */
243 static inline void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
244 {
245 	return v4l2_m2m_buf_remove(&m2m_ctx->out_q_ctx);
246 }
247 
248 /**
249  * v4l2_m2m_dst_buf_remove() - take off a destination buffer from the list of
250  * ready buffers and return it
251  *
252  * @m2m_ctx: pointer to struct v4l2_m2m_ctx
253  */
254 static inline void *v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
255 {
256 	return v4l2_m2m_buf_remove(&m2m_ctx->cap_q_ctx);
257 }
258 
259 /* v4l2 ioctl helpers */
260 
261 int v4l2_m2m_ioctl_reqbufs(struct file *file, void *priv,
262 				struct v4l2_requestbuffers *rb);
263 int v4l2_m2m_ioctl_create_bufs(struct file *file, void *fh,
264 				struct v4l2_create_buffers *create);
265 int v4l2_m2m_ioctl_querybuf(struct file *file, void *fh,
266 				struct v4l2_buffer *buf);
267 int v4l2_m2m_ioctl_expbuf(struct file *file, void *fh,
268 				struct v4l2_exportbuffer *eb);
269 int v4l2_m2m_ioctl_qbuf(struct file *file, void *fh,
270 				struct v4l2_buffer *buf);
271 int v4l2_m2m_ioctl_dqbuf(struct file *file, void *fh,
272 				struct v4l2_buffer *buf);
273 int v4l2_m2m_ioctl_prepare_buf(struct file *file, void *fh,
274 			       struct v4l2_buffer *buf);
275 int v4l2_m2m_ioctl_streamon(struct file *file, void *fh,
276 				enum v4l2_buf_type type);
277 int v4l2_m2m_ioctl_streamoff(struct file *file, void *fh,
278 				enum v4l2_buf_type type);
279 int v4l2_m2m_fop_mmap(struct file *file, struct vm_area_struct *vma);
280 unsigned int v4l2_m2m_fop_poll(struct file *file, poll_table *wait);
281 
282 #endif /* _MEDIA_V4L2_MEM2MEM_H */
283 
284