xref: /openbmc/linux/include/media/v4l2-mem2mem.h (revision f7777dcc)
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  */
44 struct v4l2_m2m_ops {
45 	void (*device_run)(void *priv);
46 	int (*job_ready)(void *priv);
47 	void (*job_abort)(void *priv);
48 	void (*lock)(void *priv);
49 	void (*unlock)(void *priv);
50 };
51 
52 struct v4l2_m2m_dev;
53 
54 struct v4l2_m2m_queue_ctx {
55 /* private: internal use only */
56 	struct vb2_queue	q;
57 
58 	/* Queue for buffers ready to be processed as soon as this
59 	 * instance receives access to the device */
60 	struct list_head	rdy_queue;
61 	spinlock_t		rdy_spinlock;
62 	u8			num_rdy;
63 	bool			buffered;
64 };
65 
66 struct v4l2_m2m_ctx {
67 /* private: internal use only */
68 	struct v4l2_m2m_dev		*m2m_dev;
69 
70 	/* Capture (output to memory) queue context */
71 	struct v4l2_m2m_queue_ctx	cap_q_ctx;
72 
73 	/* Output (input from memory) queue context */
74 	struct v4l2_m2m_queue_ctx	out_q_ctx;
75 
76 	/* For device job queue */
77 	struct list_head		queue;
78 	unsigned long			job_flags;
79 	wait_queue_head_t		finished;
80 
81 	/* Instance private data */
82 	void				*priv;
83 };
84 
85 struct v4l2_m2m_buffer {
86 	struct vb2_buffer	vb;
87 	struct list_head	list;
88 };
89 
90 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev);
91 
92 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
93 				       enum v4l2_buf_type type);
94 
95 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
96 			 struct v4l2_m2m_ctx *m2m_ctx);
97 
98 static inline void
99 v4l2_m2m_buf_done(struct vb2_buffer *buf, enum vb2_buffer_state state)
100 {
101 	vb2_buffer_done(buf, state);
102 }
103 
104 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
105 		     struct v4l2_requestbuffers *reqbufs);
106 
107 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
108 		      struct v4l2_buffer *buf);
109 
110 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
111 		  struct v4l2_buffer *buf);
112 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
113 		   struct v4l2_buffer *buf);
114 int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
115 			 struct v4l2_create_buffers *create);
116 
117 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
118 		   struct v4l2_exportbuffer *eb);
119 
120 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
121 		      enum v4l2_buf_type type);
122 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
123 		       enum v4l2_buf_type type);
124 
125 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
126 			   struct poll_table_struct *wait);
127 
128 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
129 		  struct vm_area_struct *vma);
130 
131 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops);
132 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev);
133 
134 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
135 		void *drv_priv,
136 		int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq));
137 
138 static inline void v4l2_m2m_set_src_buffered(struct v4l2_m2m_ctx *m2m_ctx,
139 					     bool buffered)
140 {
141 	m2m_ctx->out_q_ctx.buffered = buffered;
142 }
143 
144 static inline void v4l2_m2m_set_dst_buffered(struct v4l2_m2m_ctx *m2m_ctx,
145 					     bool buffered)
146 {
147 	m2m_ctx->cap_q_ctx.buffered = buffered;
148 }
149 
150 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx);
151 
152 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb);
153 
154 /**
155  * v4l2_m2m_num_src_bufs_ready() - return the number of source buffers ready for
156  * use
157  */
158 static inline
159 unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
160 {
161 	return m2m_ctx->out_q_ctx.num_rdy;
162 }
163 
164 /**
165  * v4l2_m2m_num_src_bufs_ready() - return the number of destination buffers
166  * ready for use
167  */
168 static inline
169 unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
170 {
171 	return m2m_ctx->cap_q_ctx.num_rdy;
172 }
173 
174 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx);
175 
176 /**
177  * v4l2_m2m_next_src_buf() - return next source buffer from the list of ready
178  * buffers
179  */
180 static inline void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
181 {
182 	return v4l2_m2m_next_buf(&m2m_ctx->out_q_ctx);
183 }
184 
185 /**
186  * v4l2_m2m_next_dst_buf() - return next destination buffer from the list of
187  * ready buffers
188  */
189 static inline void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
190 {
191 	return v4l2_m2m_next_buf(&m2m_ctx->cap_q_ctx);
192 }
193 
194 /**
195  * v4l2_m2m_get_src_vq() - return vb2_queue for source buffers
196  */
197 static inline
198 struct vb2_queue *v4l2_m2m_get_src_vq(struct v4l2_m2m_ctx *m2m_ctx)
199 {
200 	return &m2m_ctx->out_q_ctx.q;
201 }
202 
203 /**
204  * v4l2_m2m_get_dst_vq() - return vb2_queue for destination buffers
205  */
206 static inline
207 struct vb2_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx)
208 {
209 	return &m2m_ctx->cap_q_ctx.q;
210 }
211 
212 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx);
213 
214 /**
215  * v4l2_m2m_src_buf_remove() - take off a source buffer from the list of ready
216  * buffers and return it
217  */
218 static inline void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
219 {
220 	return v4l2_m2m_buf_remove(&m2m_ctx->out_q_ctx);
221 }
222 
223 /**
224  * v4l2_m2m_dst_buf_remove() - take off a destination buffer from the list of
225  * ready buffers and return it
226  */
227 static inline void *v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
228 {
229 	return v4l2_m2m_buf_remove(&m2m_ctx->cap_q_ctx);
230 }
231 
232 #endif /* _MEDIA_V4L2_MEM2MEM_H */
233 
234