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 };
64 
65 struct v4l2_m2m_ctx {
66 /* private: internal use only */
67 	struct v4l2_m2m_dev		*m2m_dev;
68 
69 	/* Capture (output to memory) queue context */
70 	struct v4l2_m2m_queue_ctx	cap_q_ctx;
71 
72 	/* Output (input from memory) queue context */
73 	struct v4l2_m2m_queue_ctx	out_q_ctx;
74 
75 	/* For device job queue */
76 	struct list_head		queue;
77 	unsigned long			job_flags;
78 	wait_queue_head_t		finished;
79 
80 	/* Instance private data */
81 	void				*priv;
82 };
83 
84 struct v4l2_m2m_buffer {
85 	struct vb2_buffer	vb;
86 	struct list_head	list;
87 };
88 
89 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev);
90 
91 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
92 				       enum v4l2_buf_type type);
93 
94 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
95 			 struct v4l2_m2m_ctx *m2m_ctx);
96 
97 static inline void
v4l2_m2m_buf_done(struct vb2_buffer * buf,enum vb2_buffer_state state)98 v4l2_m2m_buf_done(struct vb2_buffer *buf, enum vb2_buffer_state state)
99 {
100 	vb2_buffer_done(buf, state);
101 }
102 
103 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
104 		     struct v4l2_requestbuffers *reqbufs);
105 
106 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
107 		      struct v4l2_buffer *buf);
108 
109 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
110 		  struct v4l2_buffer *buf);
111 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
112 		   struct v4l2_buffer *buf);
113 
114 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
115 		      enum v4l2_buf_type type);
116 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
117 		       enum v4l2_buf_type type);
118 
119 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
120 			   struct poll_table_struct *wait);
121 
122 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
123 		  struct vm_area_struct *vma);
124 
125 struct v4l2_m2m_dev *v4l2_m2m_init(struct v4l2_m2m_ops *m2m_ops);
126 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev);
127 
128 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
129 		void *drv_priv,
130 		int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq));
131 
132 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx);
133 
134 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb);
135 
136 /**
137  * v4l2_m2m_num_src_bufs_ready() - return the number of source buffers ready for
138  * use
139  */
140 static inline
v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx * m2m_ctx)141 unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
142 {
143 	return m2m_ctx->cap_q_ctx.num_rdy;
144 }
145 
146 /**
147  * v4l2_m2m_num_src_bufs_ready() - return the number of destination buffers
148  * ready for use
149  */
150 static inline
v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx * m2m_ctx)151 unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
152 {
153 	return m2m_ctx->out_q_ctx.num_rdy;
154 }
155 
156 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx);
157 
158 /**
159  * v4l2_m2m_next_src_buf() - return next source buffer from the list of ready
160  * buffers
161  */
v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx * m2m_ctx)162 static inline void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
163 {
164 	return v4l2_m2m_next_buf(&m2m_ctx->out_q_ctx);
165 }
166 
167 /**
168  * v4l2_m2m_next_dst_buf() - return next destination buffer from the list of
169  * ready buffers
170  */
v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx * m2m_ctx)171 static inline void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
172 {
173 	return v4l2_m2m_next_buf(&m2m_ctx->cap_q_ctx);
174 }
175 
176 /**
177  * v4l2_m2m_get_src_vq() - return vb2_queue for source buffers
178  */
179 static inline
v4l2_m2m_get_src_vq(struct v4l2_m2m_ctx * m2m_ctx)180 struct vb2_queue *v4l2_m2m_get_src_vq(struct v4l2_m2m_ctx *m2m_ctx)
181 {
182 	return &m2m_ctx->out_q_ctx.q;
183 }
184 
185 /**
186  * v4l2_m2m_get_dst_vq() - return vb2_queue for destination buffers
187  */
188 static inline
v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx * m2m_ctx)189 struct vb2_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx)
190 {
191 	return &m2m_ctx->cap_q_ctx.q;
192 }
193 
194 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx);
195 
196 /**
197  * v4l2_m2m_src_buf_remove() - take off a source buffer from the list of ready
198  * buffers and return it
199  */
v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx * m2m_ctx)200 static inline void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
201 {
202 	return v4l2_m2m_buf_remove(&m2m_ctx->out_q_ctx);
203 }
204 
205 /**
206  * v4l2_m2m_dst_buf_remove() - take off a destination buffer from the list of
207  * ready buffers and return it
208  */
v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx * m2m_ctx)209 static inline void *v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
210 {
211 	return v4l2_m2m_buf_remove(&m2m_ctx->cap_q_ctx);
212 }
213 
214 #endif /* _MEDIA_V4L2_MEM2MEM_H */
215 
216