diff options
Diffstat (limited to '')
| -rw-r--r-- | include/media/videobuf-core.h | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/include/media/videobuf-core.h b/include/media/videobuf-core.h new file mode 100644 index 000000000..2e01b2e9a --- /dev/null +++ b/include/media/videobuf-core.h @@ -0,0 +1,233 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * generic helper functions for handling video4linux capture buffers + * + * (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org> + * + * Highly based on video-buf written originally by: + * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> + * (c) 2006 Mauro Carvalho Chehab, <mchehab@kernel.org> + * (c) 2006 Ted Walther and John Sokol + */ + +#ifndef _VIDEOBUF_CORE_H +#define _VIDEOBUF_CORE_H + +#include <linux/poll.h> +#include <linux/videodev2.h> + +#define UNSET (-1U) + + +struct videobuf_buffer; +struct videobuf_queue; + +/* --------------------------------------------------------------------- */ + +/* + * A small set of helper functions to manage video4linux buffers. + * + * struct videobuf_buffer holds the data structures used by the helper + * functions, additionally some commonly used fields for v4l buffers + * (width, height, lists, waitqueue) are in there. That struct should + * be used as first element in the drivers buffer struct. + * + * about the mmap helpers (videobuf_mmap_*): + * + * The mmaper function allows to map any subset of contiguous buffers. + * This includes one mmap() call for all buffers (which the original + * video4linux API uses) as well as one mmap() for every single buffer + * (which v4l2 uses). + * + * If there is a valid mapping for a buffer, buffer->baddr/bsize holds + * userspace address + size which can be fed into the + * videobuf_dma_init_user function listed above. + * + */ + +struct videobuf_mapping { + unsigned int count; + struct videobuf_queue *q; +}; + +enum videobuf_state { + VIDEOBUF_NEEDS_INIT = 0, + VIDEOBUF_PREPARED = 1, + VIDEOBUF_QUEUED = 2, + VIDEOBUF_ACTIVE = 3, + VIDEOBUF_DONE = 4, + VIDEOBUF_ERROR = 5, + VIDEOBUF_IDLE = 6, +}; + +struct videobuf_buffer { + unsigned int i; + u32 magic; + + /* info about the buffer */ + unsigned int width; + unsigned int height; + unsigned int bytesperline; /* use only if != 0 */ + unsigned long size; + enum v4l2_field field; + enum videobuf_state state; + struct list_head stream; /* QBUF/DQBUF list */ + + /* touched by irq handler */ + struct list_head queue; + wait_queue_head_t done; + unsigned int field_count; + u64 ts; + + /* Memory type */ + enum v4l2_memory memory; + + /* buffer size */ + size_t bsize; + + /* buffer offset (mmap + overlay) */ + size_t boff; + + /* buffer addr (userland ptr!) */ + unsigned long baddr; + + /* for mmap'ed buffers */ + struct videobuf_mapping *map; + + /* Private pointer to allow specific methods to store their data */ + int privsize; + void *priv; +}; + +struct videobuf_queue_ops { + int (*buf_setup)(struct videobuf_queue *q, + unsigned int *count, unsigned int *size); + int (*buf_prepare)(struct videobuf_queue *q, + struct videobuf_buffer *vb, + enum v4l2_field field); + void (*buf_queue)(struct videobuf_queue *q, + struct videobuf_buffer *vb); + void (*buf_release)(struct videobuf_queue *q, + struct videobuf_buffer *vb); +}; + +#define MAGIC_QTYPE_OPS 0x12261003 + +/* Helper operations - device type dependent */ +struct videobuf_qtype_ops { + u32 magic; + + struct videobuf_buffer *(*alloc_vb)(size_t size); + void *(*vaddr) (struct videobuf_buffer *buf); + int (*iolock) (struct videobuf_queue *q, + struct videobuf_buffer *vb, + struct v4l2_framebuffer *fbuf); + int (*sync) (struct videobuf_queue *q, + struct videobuf_buffer *buf); + int (*mmap_mapper) (struct videobuf_queue *q, + struct videobuf_buffer *buf, + struct vm_area_struct *vma); +}; + +struct videobuf_queue { + struct mutex vb_lock; + struct mutex *ext_lock; + spinlock_t *irqlock; + struct device *dev; + + wait_queue_head_t wait; /* wait if queue is empty */ + + enum v4l2_buf_type type; + unsigned int msize; + enum v4l2_field field; + enum v4l2_field last; /* for field=V4L2_FIELD_ALTERNATE */ + struct videobuf_buffer *bufs[VIDEO_MAX_FRAME]; + const struct videobuf_queue_ops *ops; + struct videobuf_qtype_ops *int_ops; + + unsigned int streaming:1; + unsigned int reading:1; + + /* capture via mmap() + ioctl(QBUF/DQBUF) */ + struct list_head stream; + + /* capture via read() */ + unsigned int read_off; + struct videobuf_buffer *read_buf; + + /* driver private data */ + void *priv_data; +}; + +static inline void videobuf_queue_lock(struct videobuf_queue *q) +{ + if (!q->ext_lock) + mutex_lock(&q->vb_lock); +} + +static inline void videobuf_queue_unlock(struct videobuf_queue *q) +{ + if (!q->ext_lock) + mutex_unlock(&q->vb_lock); +} + +int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb, + int non_blocking, int intr); +int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb, + struct v4l2_framebuffer *fbuf); + +struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q); + +/* Used on videobuf-dvb */ +void *videobuf_queue_to_vaddr(struct videobuf_queue *q, + struct videobuf_buffer *buf); + +void videobuf_queue_core_init(struct videobuf_queue *q, + const struct videobuf_queue_ops *ops, + struct device *dev, + spinlock_t *irqlock, + enum v4l2_buf_type type, + enum v4l2_field field, + unsigned int msize, + void *priv, + struct videobuf_qtype_ops *int_ops, + struct mutex *ext_lock); +int videobuf_queue_is_busy(struct videobuf_queue *q); +void videobuf_queue_cancel(struct videobuf_queue *q); + +enum v4l2_field videobuf_next_field(struct videobuf_queue *q); +int videobuf_reqbufs(struct videobuf_queue *q, + struct v4l2_requestbuffers *req); +int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b); +int videobuf_qbuf(struct videobuf_queue *q, + struct v4l2_buffer *b); +int videobuf_dqbuf(struct videobuf_queue *q, + struct v4l2_buffer *b, int nonblocking); +int videobuf_streamon(struct videobuf_queue *q); +int videobuf_streamoff(struct videobuf_queue *q); + +void videobuf_stop(struct videobuf_queue *q); + +int videobuf_read_start(struct videobuf_queue *q); +void videobuf_read_stop(struct videobuf_queue *q); +ssize_t videobuf_read_stream(struct videobuf_queue *q, + char __user *data, size_t count, loff_t *ppos, + int vbihack, int nonblocking); +ssize_t videobuf_read_one(struct videobuf_queue *q, + char __user *data, size_t count, loff_t *ppos, + int nonblocking); +__poll_t videobuf_poll_stream(struct file *file, + struct videobuf_queue *q, + poll_table *wait); + +int videobuf_mmap_setup(struct videobuf_queue *q, + unsigned int bcount, unsigned int bsize, + enum v4l2_memory memory); +int __videobuf_mmap_setup(struct videobuf_queue *q, + unsigned int bcount, unsigned int bsize, + enum v4l2_memory memory); +int videobuf_mmap_free(struct videobuf_queue *q); +int videobuf_mmap_mapper(struct videobuf_queue *q, + struct vm_area_struct *vma); + +#endif |