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	unsigned int            input;
 76	enum v4l2_field         field;
 77	enum videobuf_state     state;
 78	struct list_head        stream;  /* QBUF/DQBUF list */
 79
 80	/* touched by irq handler */
 81	struct list_head        queue;
 82	wait_queue_head_t       done;
 83	unsigned int            field_count;
 84	struct timeval          ts;
 85
 86	/* Memory type */
 87	enum v4l2_memory        memory;
 88
 89	/* buffer size */
 90	size_t                  bsize;
 91
 92	/* buffer offset (mmap + overlay) */
 93	size_t                  boff;
 94
 95	/* buffer addr (userland ptr!) */
 96	unsigned long           baddr;
 97
 98	/* for mmap'ed buffers */
 99	struct videobuf_mapping *map;
100
101	/* Private pointer to allow specific methods to store their data */
102	int			privsize;
103	void                    *priv;
104};
105
106struct videobuf_queue_ops {
107	int (*buf_setup)(struct videobuf_queue *q,
108			 unsigned int *count, unsigned int *size);
109	int (*buf_prepare)(struct videobuf_queue *q,
110			   struct videobuf_buffer *vb,
111			   enum v4l2_field field);
112	void (*buf_queue)(struct videobuf_queue *q,
113			  struct videobuf_buffer *vb);
114	void (*buf_release)(struct videobuf_queue *q,
115			    struct videobuf_buffer *vb);
116};
117
118#define MAGIC_QTYPE_OPS	0x12261003
119
120/* Helper operations - device type dependent */
121struct videobuf_qtype_ops {
122	u32                     magic;
123
124	struct videobuf_buffer *(*alloc_vb)(size_t size);
125	void *(*vaddr)		(struct videobuf_buffer *buf);
126	int (*iolock)		(struct videobuf_queue *q,
127				 struct videobuf_buffer *vb,
128				 struct v4l2_framebuffer *fbuf);
129	int (*sync)		(struct videobuf_queue *q,
130				 struct videobuf_buffer *buf);
131	int (*mmap_mapper)	(struct videobuf_queue *q,
132				 struct videobuf_buffer *buf,
133				 struct vm_area_struct *vma);
134};
135
136struct videobuf_queue {
137	struct mutex               vb_lock;
138	struct mutex               *ext_lock;
139	spinlock_t                 *irqlock;
140	struct device		   *dev;
141
142	wait_queue_head_t	   wait; /* wait if queue is empty */
143
144	enum v4l2_buf_type         type;
145	unsigned int               inputs; /* for V4L2_BUF_FLAG_INPUT */
146	unsigned int               msize;
147	enum v4l2_field            field;
148	enum v4l2_field            last;   /* for field=V4L2_FIELD_ALTERNATE */
149	struct videobuf_buffer     *bufs[VIDEO_MAX_FRAME];
150	const struct videobuf_queue_ops  *ops;
151	struct videobuf_qtype_ops  *int_ops;
152
153	unsigned int               streaming:1;
154	unsigned int               reading:1;
155
156	/* capture via mmap() + ioctl(QBUF/DQBUF) */
157	struct list_head           stream;
158
159	/* capture via read() */
160	unsigned int               read_off;
161	struct videobuf_buffer     *read_buf;
162
163	/* driver private data */
164	void                       *priv_data;
165};
166
167static inline void videobuf_queue_lock(struct videobuf_queue *q)
168{
169	if (!q->ext_lock)
170		mutex_lock(&q->vb_lock);
171}
172
173static inline void videobuf_queue_unlock(struct videobuf_queue *q)
174{
175	if (!q->ext_lock)
176		mutex_unlock(&q->vb_lock);
177}
178
179int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
180		int non_blocking, int intr);
181int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
182		struct v4l2_framebuffer *fbuf);
183
184struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q);
185
186/* Used on videobuf-dvb */
187void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
188			      struct videobuf_buffer *buf);
189
190void videobuf_queue_core_init(struct videobuf_queue *q,
191			 const struct videobuf_queue_ops *ops,
192			 struct device *dev,
193			 spinlock_t *irqlock,
194			 enum v4l2_buf_type type,
195			 enum v4l2_field field,
196			 unsigned int msize,
197			 void *priv,
198			 struct videobuf_qtype_ops *int_ops,
199			 struct mutex *ext_lock);
200int  videobuf_queue_is_busy(struct videobuf_queue *q);
201void videobuf_queue_cancel(struct videobuf_queue *q);
202
203enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
204int videobuf_reqbufs(struct videobuf_queue *q,
205		     struct v4l2_requestbuffers *req);
206int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
207int videobuf_qbuf(struct videobuf_queue *q,
208		  struct v4l2_buffer *b);
209int videobuf_dqbuf(struct videobuf_queue *q,
210		   struct v4l2_buffer *b, int nonblocking);
211int videobuf_streamon(struct videobuf_queue *q);
212int videobuf_streamoff(struct videobuf_queue *q);
213
214void videobuf_stop(struct videobuf_queue *q);
215
216int videobuf_read_start(struct videobuf_queue *q);
217void videobuf_read_stop(struct videobuf_queue *q);
218ssize_t videobuf_read_stream(struct videobuf_queue *q,
219			     char __user *data, size_t count, loff_t *ppos,
220			     int vbihack, int nonblocking);
221ssize_t videobuf_read_one(struct videobuf_queue *q,
222			  char __user *data, size_t count, loff_t *ppos,
223			  int nonblocking);
224unsigned int videobuf_poll_stream(struct file *file,
225				  struct videobuf_queue *q,
226				  poll_table *wait);
227
228int videobuf_mmap_setup(struct videobuf_queue *q,
229			unsigned int bcount, unsigned int bsize,
230			enum v4l2_memory memory);
231int __videobuf_mmap_setup(struct videobuf_queue *q,
232			unsigned int bcount, unsigned int bsize,
233			enum v4l2_memory memory);
234int videobuf_mmap_free(struct videobuf_queue *q);
235int videobuf_mmap_mapper(struct videobuf_queue *q,
236			 struct vm_area_struct *vma);
237
238#endif