1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * generic helper functions for handling video4linux capture buffers
4 *
5 * (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org>
6 *
7 * Highly based on video-buf written originally by:
8 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
9 * (c) 2006 Mauro Carvalho Chehab, <mchehab@kernel.org>
10 * (c) 2006 Ted Walther and John Sokol
11 */
12
13#ifndef _VIDEOBUF_CORE_H
14#define _VIDEOBUF_CORE_H
15
16#include <linux/poll.h>
17#include <linux/videodev2.h>
18
19#define UNSET (-1U)
20
21
22struct videobuf_buffer;
23struct videobuf_queue;
24
25/* --------------------------------------------------------------------- */
26
27/*
28 * A small set of helper functions to manage video4linux buffers.
29 *
30 * struct videobuf_buffer holds the data structures used by the helper
31 * functions, additionally some commonly used fields for v4l buffers
32 * (width, height, lists, waitqueue) are in there.  That struct should
33 * be used as first element in the drivers buffer struct.
34 *
35 * about the mmap helpers (videobuf_mmap_*):
36 *
37 * The mmaper function allows to map any subset of contiguous buffers.
38 * This includes one mmap() call for all buffers (which the original
39 * video4linux API uses) as well as one mmap() for every single buffer
40 * (which v4l2 uses).
41 *
42 * If there is a valid mapping for a buffer, buffer->baddr/bsize holds
43 * userspace address + size which can be fed into the
44 * videobuf_dma_init_user function listed above.
45 *
46 */
47
48struct videobuf_mapping {
49	unsigned int count;
50	struct videobuf_queue *q;
51};
52
53enum videobuf_state {
54	VIDEOBUF_NEEDS_INIT = 0,
55	VIDEOBUF_PREPARED   = 1,
56	VIDEOBUF_QUEUED     = 2,
57	VIDEOBUF_ACTIVE     = 3,
58	VIDEOBUF_DONE       = 4,
59	VIDEOBUF_ERROR      = 5,
60	VIDEOBUF_IDLE       = 6,
61};
62
63struct videobuf_buffer {
64	unsigned int            i;
65	u32                     magic;
66
67	/* info about the buffer */
68	unsigned int            width;
69	unsigned int            height;
70	unsigned int            bytesperline; /* use only if != 0 */
71	unsigned long           size;
72	enum v4l2_field         field;
73	enum videobuf_state     state;
74	struct list_head        stream;  /* QBUF/DQBUF list */
75
76	/* touched by irq handler */
77	struct list_head        queue;
78	wait_queue_head_t       done;
79	unsigned int            field_count;
80	u64			ts;
81
82	/* Memory type */
83	enum v4l2_memory        memory;
84
85	/* buffer size */
86	size_t                  bsize;
87
88	/* buffer offset (mmap + overlay) */
89	size_t                  boff;
90
91	/* buffer addr (userland ptr!) */
92	unsigned long           baddr;
93
94	/* for mmap'ed buffers */
95	struct videobuf_mapping *map;
96
97	/* Private pointer to allow specific methods to store their data */
98	int			privsize;
99	void                    *priv;
100};
101
102struct videobuf_queue_ops {
103	int (*buf_setup)(struct videobuf_queue *q,
104			 unsigned int *count, unsigned int *size);
105	int (*buf_prepare)(struct videobuf_queue *q,
106			   struct videobuf_buffer *vb,
107			   enum v4l2_field field);
108	void (*buf_queue)(struct videobuf_queue *q,
109			  struct videobuf_buffer *vb);
110	void (*buf_release)(struct videobuf_queue *q,
111			    struct videobuf_buffer *vb);
112};
113
114#define MAGIC_QTYPE_OPS	0x12261003
115
116/* Helper operations - device type dependent */
117struct videobuf_qtype_ops {
118	u32                     magic;
119
120	struct videobuf_buffer *(*alloc_vb)(size_t size);
121	void *(*vaddr)		(struct videobuf_buffer *buf);
122	int (*iolock)		(struct videobuf_queue *q,
123				 struct videobuf_buffer *vb,
124				 struct v4l2_framebuffer *fbuf);
125	int (*sync)		(struct videobuf_queue *q,
126				 struct videobuf_buffer *buf);
127	int (*mmap_mapper)	(struct videobuf_queue *q,
128				 struct videobuf_buffer *buf,
129				 struct vm_area_struct *vma);
130};
131
132struct videobuf_queue {
133	struct mutex               vb_lock;
134	struct mutex               *ext_lock;
135	spinlock_t                 *irqlock;
136	struct device		   *dev;
137
138	wait_queue_head_t	   wait; /* wait if queue is empty */
139
140	enum v4l2_buf_type         type;
141	unsigned int               msize;
142	enum v4l2_field            field;
143	enum v4l2_field            last;   /* for field=V4L2_FIELD_ALTERNATE */
144	struct videobuf_buffer     *bufs[VIDEO_MAX_FRAME];
145	const struct videobuf_queue_ops  *ops;
146	struct videobuf_qtype_ops  *int_ops;
147
148	unsigned int               streaming:1;
149	unsigned int               reading:1;
150
151	/* capture via mmap() + ioctl(QBUF/DQBUF) */
152	struct list_head           stream;
153
154	/* capture via read() */
155	unsigned int               read_off;
156	struct videobuf_buffer     *read_buf;
157
158	/* driver private data */
159	void                       *priv_data;
160};
161
162static inline void videobuf_queue_lock(struct videobuf_queue *q)
163{
164	if (!q->ext_lock)
165		mutex_lock(&q->vb_lock);
166}
167
168static inline void videobuf_queue_unlock(struct videobuf_queue *q)
169{
170	if (!q->ext_lock)
171		mutex_unlock(&q->vb_lock);
172}
173
174int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
175		int non_blocking, int intr);
176int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
177		struct v4l2_framebuffer *fbuf);
178
179struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q);
180
181/* Used on videobuf-dvb */
182void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
183			      struct videobuf_buffer *buf);
184
185void videobuf_queue_core_init(struct videobuf_queue *q,
186			 const struct videobuf_queue_ops *ops,
187			 struct device *dev,
188			 spinlock_t *irqlock,
189			 enum v4l2_buf_type type,
190			 enum v4l2_field field,
191			 unsigned int msize,
192			 void *priv,
193			 struct videobuf_qtype_ops *int_ops,
194			 struct mutex *ext_lock);
195int  videobuf_queue_is_busy(struct videobuf_queue *q);
196void videobuf_queue_cancel(struct videobuf_queue *q);
197
198enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
199int videobuf_reqbufs(struct videobuf_queue *q,
200		     struct v4l2_requestbuffers *req);
201int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
202int videobuf_qbuf(struct videobuf_queue *q,
203		  struct v4l2_buffer *b);
204int videobuf_dqbuf(struct videobuf_queue *q,
205		   struct v4l2_buffer *b, int nonblocking);
206int videobuf_streamon(struct videobuf_queue *q);
207int videobuf_streamoff(struct videobuf_queue *q);
208
209void videobuf_stop(struct videobuf_queue *q);
210
211int videobuf_read_start(struct videobuf_queue *q);
212void videobuf_read_stop(struct videobuf_queue *q);
213ssize_t videobuf_read_stream(struct videobuf_queue *q,
214			     char __user *data, size_t count, loff_t *ppos,
215			     int vbihack, int nonblocking);
216ssize_t videobuf_read_one(struct videobuf_queue *q,
217			  char __user *data, size_t count, loff_t *ppos,
218			  int nonblocking);
219__poll_t videobuf_poll_stream(struct file *file,
220				  struct videobuf_queue *q,
221				  poll_table *wait);
222
223int videobuf_mmap_setup(struct videobuf_queue *q,
224			unsigned int bcount, unsigned int bsize,
225			enum v4l2_memory memory);
226int __videobuf_mmap_setup(struct videobuf_queue *q,
227			unsigned int bcount, unsigned int bsize,
228			enum v4l2_memory memory);
229int videobuf_mmap_free(struct videobuf_queue *q);
230int videobuf_mmap_mapper(struct videobuf_queue *q,
231			 struct vm_area_struct *vma);
232
233#endif
234