1/*
2 * generic helper functions for handling video4linux capture buffers
3 *
4 * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
5 *
6 * Highly based on video-buf written originally by:
7 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
8 * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
9 * (c) 2006 Ted Walther and John Sokol
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
13 * the Free Software Foundation; either version 2
14 */
15
16#ifndef _VIDEOBUF_CORE_H
17#define _VIDEOBUF_CORE_H
18
19#include <linux/poll.h>
20#include <linux/videodev2.h>
21
22#define UNSET (-1U)
23
24
25struct videobuf_buffer;
26struct videobuf_queue;
27
28/* --------------------------------------------------------------------- */
29
30/*
31 * A small set of helper functions to manage video4linux buffers.
32 *
33 * struct videobuf_buffer holds the data structures used by the helper
34 * functions, additionally some commonly used fields for v4l buffers
35 * (width, height, lists, waitqueue) are in there.  That struct should
36 * be used as first element in the drivers buffer struct.
37 *
38 * about the mmap helpers (videobuf_mmap_*):
39 *
40 * The mmaper function allows to map any subset of contingous buffers.
41 * This includes one mmap() call for all buffers (which the original
42 * video4linux API uses) as well as one mmap() for every single buffer
43 * (which v4l2 uses).
44 *
45 * If there is a valid mapping for a buffer, buffer->baddr/bsize holds
46 * userspace address + size which can be feeded into the
47 * videobuf_dma_init_user function listed above.
48 *
49 */
50
51struct videobuf_mapping {
52	unsigned int count;
53	struct videobuf_queue *q;
54};
55
56enum videobuf_state {
57	VIDEOBUF_NEEDS_INIT = 0,
58	VIDEOBUF_PREPARED   = 1,
59	VIDEOBUF_QUEUED     = 2,
60	VIDEOBUF_ACTIVE     = 3,
61	VIDEOBUF_DONE       = 4,
62	VIDEOBUF_ERROR      = 5,
63	VIDEOBUF_IDLE       = 6,
64};
65
66struct videobuf_buffer {
67	unsigned int            i;
68	u32                     magic;
69
70	/* info about the buffer */
71	unsigned int            width;
72	unsigned int            height;
73	unsigned int            bytesperline; /* use only if != 0 */
74	unsigned long           size;
75	enum v4l2_field         field;
76	enum videobuf_state     state;
77	struct list_head        stream;  /* QBUF/DQBUF list */
78
79	/* touched by irq handler */
80	struct list_head        queue;
81	wait_queue_head_t       done;
82	unsigned int            field_count;
83	struct timeval          ts;
84
85	/* Memory type */
86	enum v4l2_memory        memory;
87
88	/* buffer size */
89	size_t                  bsize;
90
91	/* buffer offset (mmap + overlay) */
92	size_t                  boff;
93
94	/* buffer addr (userland ptr!) */
95	unsigned long           baddr;
96
97	/* for mmap'ed buffers */
98	struct videobuf_mapping *map;
99
100	/* Private pointer to allow specific methods to store their data */
101	int			privsize;
102	void                    *priv;
103};
104
105struct videobuf_queue_ops {
106	int (*buf_setup)(struct videobuf_queue *q,
107			 unsigned int *count, unsigned int *size);
108	int (*buf_prepare)(struct videobuf_queue *q,
109			   struct videobuf_buffer *vb,
110			   enum v4l2_field field);
111	void (*buf_queue)(struct videobuf_queue *q,
112			  struct videobuf_buffer *vb);
113	void (*buf_release)(struct videobuf_queue *q,
114			    struct videobuf_buffer *vb);
115};
116
117#define MAGIC_QTYPE_OPS	0x12261003
118
119/* Helper operations - device type dependent */
120struct videobuf_qtype_ops {
121	u32                     magic;
122
123	struct videobuf_buffer *(*alloc_vb)(size_t size);
124	void *(*vaddr)		(struct videobuf_buffer *buf);
125	int (*iolock)		(struct videobuf_queue *q,
126				 struct videobuf_buffer *vb,
127				 struct v4l2_framebuffer *fbuf);
128	int (*sync)		(struct videobuf_queue *q,
129				 struct videobuf_buffer *buf);
130	int (*mmap_mapper)	(struct videobuf_queue *q,
131				 struct videobuf_buffer *buf,
132				 struct vm_area_struct *vma);
133};
134
135struct videobuf_queue {
136	struct mutex               vb_lock;
137	struct mutex               *ext_lock;
138	spinlock_t                 *irqlock;
139	struct device		   *dev;
140
141	wait_queue_head_t	   wait; /* wait if queue is empty */
142
143	enum v4l2_buf_type         type;
144	unsigned int               msize;
145	enum v4l2_field            field;
146	enum v4l2_field            last;   /* for field=V4L2_FIELD_ALTERNATE */
147	struct videobuf_buffer     *bufs[VIDEO_MAX_FRAME];
148	const struct videobuf_queue_ops  *ops;
149	struct videobuf_qtype_ops  *int_ops;
150
151	unsigned int               streaming:1;
152	unsigned int               reading:1;
153
154	/* capture via mmap() + ioctl(QBUF/DQBUF) */
155	struct list_head           stream;
156
157	/* capture via read() */
158	unsigned int               read_off;
159	struct videobuf_buffer     *read_buf;
160
161	/* driver private data */
162	void                       *priv_data;
163};
164
165static inline void videobuf_queue_lock(struct videobuf_queue *q)
166{
167	if (!q->ext_lock)
168		mutex_lock(&q->vb_lock);
169}
170
171static inline void videobuf_queue_unlock(struct videobuf_queue *q)
172{
173	if (!q->ext_lock)
174		mutex_unlock(&q->vb_lock);
175}
176
177int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
178		int non_blocking, int intr);
179int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
180		struct v4l2_framebuffer *fbuf);
181
182struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q);
183
184/* Used on videobuf-dvb */
185void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
186			      struct videobuf_buffer *buf);
187
188void videobuf_queue_core_init(struct videobuf_queue *q,
189			 const struct videobuf_queue_ops *ops,
190			 struct device *dev,
191			 spinlock_t *irqlock,
192			 enum v4l2_buf_type type,
193			 enum v4l2_field field,
194			 unsigned int msize,
195			 void *priv,
196			 struct videobuf_qtype_ops *int_ops,
197			 struct mutex *ext_lock);
198int  videobuf_queue_is_busy(struct videobuf_queue *q);
199void videobuf_queue_cancel(struct videobuf_queue *q);
200
201enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
202int videobuf_reqbufs(struct videobuf_queue *q,
203		     struct v4l2_requestbuffers *req);
204int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
205int videobuf_qbuf(struct videobuf_queue *q,
206		  struct v4l2_buffer *b);
207int videobuf_dqbuf(struct videobuf_queue *q,
208		   struct v4l2_buffer *b, int nonblocking);
209int videobuf_streamon(struct videobuf_queue *q);
210int videobuf_streamoff(struct videobuf_queue *q);
211
212void videobuf_stop(struct videobuf_queue *q);
213
214int videobuf_read_start(struct videobuf_queue *q);
215void videobuf_read_stop(struct videobuf_queue *q);
216ssize_t videobuf_read_stream(struct videobuf_queue *q,
217			     char __user *data, size_t count, loff_t *ppos,
218			     int vbihack, int nonblocking);
219ssize_t videobuf_read_one(struct videobuf_queue *q,
220			  char __user *data, size_t count, loff_t *ppos,
221			  int nonblocking);
222unsigned int videobuf_poll_stream(struct file *file,
223				  struct videobuf_queue *q,
224				  poll_table *wait);
225
226int videobuf_mmap_setup(struct videobuf_queue *q,
227			unsigned int bcount, unsigned int bsize,
228			enum v4l2_memory memory);
229int __videobuf_mmap_setup(struct videobuf_queue *q,
230			unsigned int bcount, unsigned int bsize,
231			enum v4l2_memory memory);
232int videobuf_mmap_free(struct videobuf_queue *q);
233int videobuf_mmap_mapper(struct videobuf_queue *q,
234			 struct vm_area_struct *vma);
235
236#endif
237