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Diffstat (limited to 'include/media/videobuf2-core.h')
| -rw-r--r-- | include/media/videobuf2-core.h | 506 |
1 files changed, 506 insertions, 0 deletions
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h new file mode 100644 index 0000000..d88a098 --- /dev/null +++ b/include/media/videobuf2-core.h @@ -0,0 +1,506 @@ +/* + * videobuf2-core.h - V4L2 driver helper framework + * + * Copyright (C) 2010 Samsung Electronics + * + * Author: Pawel Osciak <pawel@osciak.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation. + */ +#ifndef _MEDIA_VIDEOBUF2_CORE_H +#define _MEDIA_VIDEOBUF2_CORE_H + +#include <linux/mm_types.h> +#include <linux/mutex.h> +#include <linux/poll.h> +#include <linux/videodev2.h> +#include <linux/dma-buf.h> + +struct vb2_alloc_ctx; +struct vb2_fileio_data; + +/** + * struct vb2_mem_ops - memory handling/memory allocator operations + * @alloc: allocate video memory and, optionally, allocator private data, + * return NULL on failure or a pointer to allocator private, + * per-buffer data on success; the returned private structure + * will then be passed as buf_priv argument to other ops in this + * structure. Additional gfp_flags to use when allocating the + * are also passed to this operation. These flags are from the + * gfp_flags field of vb2_queue. + * @put: inform the allocator that the buffer will no longer be used; + * usually will result in the allocator freeing the buffer (if + * no other users of this buffer are present); the buf_priv + * argument is the allocator private per-buffer structure + * previously returned from the alloc callback + * @get_userptr: acquire userspace memory for a hardware operation; used for + * USERPTR memory types; vaddr is the address passed to the + * videobuf layer when queuing a video buffer of USERPTR type; + * should return an allocator private per-buffer structure + * associated with the buffer on success, NULL on failure; + * the returned private structure will then be passed as buf_priv + * argument to other ops in this structure + * @put_userptr: inform the allocator that a USERPTR buffer will no longer + * be used + * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation; + * used for DMABUF memory types; alloc_ctx is the alloc context + * dbuf is the shared dma_buf; returns NULL on failure; + * allocator private per-buffer structure on success; + * this needs to be used for further accesses to the buffer + * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF + * buffer is no longer used; the buf_priv argument is the + * allocator private per-buffer structure previously returned + * from the attach_dmabuf callback + * @map_dmabuf: request for access to the dmabuf from allocator; the allocator + * of dmabuf is informed that this driver is going to use the + * dmabuf + * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified + * that this driver is done using the dmabuf for now + * @prepare: called every time the buffer is passed from userspace to the + * driver, useful for cache synchronisation, optional + * @finish: called every time the buffer is passed back from the driver + * to the userspace, also optional + * @vaddr: return a kernel virtual address to a given memory buffer + * associated with the passed private structure or NULL if no + * such mapping exists + * @cookie: return allocator specific cookie for a given memory buffer + * associated with the passed private structure or NULL if not + * available + * @num_users: return the current number of users of a memory buffer; + * return 1 if the videobuf layer (or actually the driver using + * it) is the only user + * @mmap: setup a userspace mapping for a given memory buffer under + * the provided virtual memory region + * + * Required ops for USERPTR types: get_userptr, put_userptr. + * Required ops for MMAP types: alloc, put, num_users, mmap. + * Required ops for read/write access types: alloc, put, num_users, vaddr + * Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, map_dmabuf, + * unmap_dmabuf. + */ +struct vb2_mem_ops { + void *(*alloc)(void *alloc_ctx, unsigned long size, gfp_t gfp_flags); + void (*put)(void *buf_priv); + struct dma_buf *(*get_dmabuf)(void *buf_priv); + + void *(*get_userptr)(void *alloc_ctx, unsigned long vaddr, + unsigned long size, int write); + void (*put_userptr)(void *buf_priv); + + void (*prepare)(void *buf_priv); + void (*finish)(void *buf_priv); + + void *(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf, + unsigned long size, int write); + void (*detach_dmabuf)(void *buf_priv); + int (*map_dmabuf)(void *buf_priv); + void (*unmap_dmabuf)(void *buf_priv); + + void *(*vaddr)(void *buf_priv); + void *(*cookie)(void *buf_priv); + + unsigned int (*num_users)(void *buf_priv); + + int (*mmap)(void *buf_priv, struct vm_area_struct *vma); +}; + +struct vb2_plane { + void *mem_priv; + struct dma_buf *dbuf; + unsigned int dbuf_mapped; +}; + +/** + * enum vb2_io_modes - queue access methods + * @VB2_MMAP: driver supports MMAP with streaming API + * @VB2_USERPTR: driver supports USERPTR with streaming API + * @VB2_READ: driver supports read() style access + * @VB2_WRITE: driver supports write() style access + * @VB2_DMABUF: driver supports DMABUF with streaming API + */ +enum vb2_io_modes { + VB2_MMAP = (1 << 0), + VB2_USERPTR = (1 << 1), + VB2_READ = (1 << 2), + VB2_WRITE = (1 << 3), + VB2_DMABUF = (1 << 4), +}; + +/** + * enum vb2_fileio_flags - flags for selecting a mode of the file io emulator, + * by default the 'streaming' style is used by the file io emulator + * @VB2_FILEIO_READ_ONCE: report EOF after reading the first buffer + * @VB2_FILEIO_WRITE_IMMEDIATELY: queue buffer after each write() call + */ +enum vb2_fileio_flags { + VB2_FILEIO_READ_ONCE = (1 << 0), + VB2_FILEIO_WRITE_IMMEDIATELY = (1 << 1), +}; + +/** + * enum vb2_buffer_state - current video buffer state + * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control + * @VB2_BUF_STATE_PREPARED: buffer prepared in videobuf and by the driver + * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver + * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used + * in a hardware operation + * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but + * not yet dequeued to userspace + * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer + * has ended with an error, which will be reported + * to the userspace when it is dequeued + */ +enum vb2_buffer_state { + VB2_BUF_STATE_DEQUEUED, + VB2_BUF_STATE_PREPARED, + VB2_BUF_STATE_QUEUED, + VB2_BUF_STATE_ACTIVE, + VB2_BUF_STATE_DONE, + VB2_BUF_STATE_ERROR, +}; + +struct vb2_queue; + +/** + * struct vb2_buffer - represents a video buffer + * @v4l2_buf: struct v4l2_buffer associated with this buffer; can + * be read by the driver and relevant entries can be + * changed by the driver in case of CAPTURE types + * (such as timestamp) + * @v4l2_planes: struct v4l2_planes associated with this buffer; can + * be read by the driver and relevant entries can be + * changed by the driver in case of CAPTURE types + * (such as bytesused); NOTE that even for single-planar + * types, the v4l2_planes[0] struct should be used + * instead of v4l2_buf for filling bytesused - drivers + * should use the vb2_set_plane_payload() function for that + * @vb2_queue: the queue to which this driver belongs + * @num_planes: number of planes in the buffer + * on an internal driver queue + * @state: current buffer state; do not change + * @queued_entry: entry on the queued buffers list, which holds all + * buffers queued from userspace + * @done_entry: entry on the list that stores all buffers ready to + * be dequeued to userspace + * @planes: private per-plane information; do not change + */ +struct vb2_buffer { + struct v4l2_buffer v4l2_buf; + struct v4l2_plane v4l2_planes[VIDEO_MAX_PLANES]; + + struct vb2_queue *vb2_queue; + + unsigned int num_planes; + +/* Private: internal use only */ + enum vb2_buffer_state state; + + struct list_head queued_entry; + struct list_head done_entry; + + struct vb2_plane planes[VIDEO_MAX_PLANES]; +}; + +/** + * struct vb2_ops - driver-specific callbacks + * + * @queue_setup: called from VIDIOC_REQBUFS and VIDIOC_CREATE_BUFS + * handlers before memory allocation, or, if + * *num_planes != 0, after the allocation to verify a + * smaller number of buffers. Driver should return + * the required number of buffers in *num_buffers, the + * required number of planes per buffer in *num_planes; the + * size of each plane should be set in the sizes[] array + * and optional per-plane allocator specific context in the + * alloc_ctxs[] array. When called from VIDIOC_REQBUFS, + * fmt == NULL, the driver has to use the currently + * configured format and *num_buffers is the total number + * of buffers, that are being allocated. When called from + * VIDIOC_CREATE_BUFS, fmt != NULL and it describes the + * target frame format. In this case *num_buffers are being + * allocated additionally to q->num_buffers. + * @wait_prepare: release any locks taken while calling vb2 functions; + * it is called before an ioctl needs to wait for a new + * buffer to arrive; required to avoid a deadlock in + * blocking access type + * @wait_finish: reacquire all locks released in the previous callback; + * required to continue operation after sleeping while + * waiting for a new buffer to arrive + * @buf_init: called once after allocating a buffer (in MMAP case) + * or after acquiring a new USERPTR buffer; drivers may + * perform additional buffer-related initialization; + * initialization failure (return != 0) will prevent + * queue setup from completing successfully; optional + * @buf_prepare: called every time the buffer is queued from userspace + * and from the VIDIOC_PREPARE_BUF ioctl; drivers may + * perform any initialization required before each hardware + * operation in this callback; if an error is returned, the + * buffer will not be queued in driver; optional + * @buf_finish: called before every dequeue of the buffer back to + * userspace; drivers may perform any operations required + * before userspace accesses the buffer; optional + * @buf_cleanup: called once before the buffer is freed; drivers may + * perform any additional cleanup; optional + * @start_streaming: called once to enter 'streaming' state; the driver may + * receive buffers with @buf_queue callback before + * @start_streaming is called; the driver gets the number + * of already queued buffers in count parameter; driver + * can return an error if hardware fails or not enough + * buffers has been queued, in such case all buffers that + * have been already given by the @buf_queue callback are + * invalidated. + * @stop_streaming: called when 'streaming' state must be disabled; driver + * should stop any DMA transactions or wait until they + * finish and give back all buffers it got from buf_queue() + * callback; may use vb2_wait_for_all_buffers() function + * @buf_queue: passes buffer vb to the driver; driver may start + * hardware operation on this buffer; driver should give + * the buffer back by calling vb2_buffer_done() function; + * it is allways called after calling STREAMON ioctl; + * might be called before start_streaming callback if user + * pre-queued buffers before calling STREAMON + */ +struct vb2_ops { + int (*queue_setup)(struct vb2_queue *q, const struct v4l2_format *fmt, + unsigned int *num_buffers, unsigned int *num_planes, + unsigned int sizes[], void *alloc_ctxs[]); + + void (*wait_prepare)(struct vb2_queue *q); + void (*wait_finish)(struct vb2_queue *q); + + int (*buf_init)(struct vb2_buffer *vb); + int (*buf_prepare)(struct vb2_buffer *vb); + int (*buf_finish)(struct vb2_buffer *vb); + void (*buf_cleanup)(struct vb2_buffer *vb); + + int (*start_streaming)(struct vb2_queue *q, unsigned int count); + int (*stop_streaming)(struct vb2_queue *q); + + void (*buf_queue)(struct vb2_buffer *vb); +}; + +struct v4l2_fh; + +/** + * struct vb2_queue - a videobuf queue + * + * @type: queue type (see V4L2_BUF_TYPE_* in linux/videodev2.h + * @io_modes: supported io methods (see vb2_io_modes enum) + * @io_flags: additional io flags (see vb2_fileio_flags enum) + * @lock: pointer to a mutex that protects the vb2_queue struct. The + * driver can set this to a mutex to let the v4l2 core serialize + * the queuing ioctls. If the driver wants to handle locking + * itself, then this should be set to NULL. This lock is not used + * by the videobuf2 core API. + * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle + * that called reqbufs, create_buffers or started fileio. + * This field is not used by the videobuf2 core API, but it allows + * drivers to easily associate an owner filehandle with the queue. + * @ops: driver-specific callbacks + * @mem_ops: memory allocator specific callbacks + * @drv_priv: driver private data + * @buf_struct_size: size of the driver-specific buffer structure; + * "0" indicates the driver doesn't want to use a custom buffer + * structure type, so sizeof(struct vb2_buffer) will is used + * @gfp_flags: additional gfp flags used when allocating the buffers. + * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32 + * to force the buffer allocation to a specific memory zone. + * + * @memory: current memory type used + * @bufs: videobuf buffer structures + * @num_buffers: number of allocated/used buffers + * @queued_list: list of buffers currently queued from userspace + * @queued_count: number of buffers owned by the driver + * @done_list: list of buffers ready to be dequeued to userspace + * @done_lock: lock to protect done_list list + * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued + * @alloc_ctx: memory type/allocator-specific contexts for each plane + * @streaming: current streaming state + * @fileio: file io emulator internal data, used only if emulator is active + */ +struct vb2_queue { + enum v4l2_buf_type type; + unsigned int io_modes; + unsigned int io_flags; + struct mutex *lock; + struct v4l2_fh *owner; + + const struct vb2_ops *ops; + const struct vb2_mem_ops *mem_ops; + void *drv_priv; + unsigned int buf_struct_size; + u32 timestamp_type; + gfp_t gfp_flags; + +/* private: internal use only */ + enum v4l2_memory memory; + struct vb2_buffer *bufs[VIDEO_MAX_FRAME]; + unsigned int num_buffers; + + struct list_head queued_list; + + atomic_t queued_count; + struct list_head done_list; + spinlock_t done_lock; + wait_queue_head_t done_wq; + + void *alloc_ctx[VIDEO_MAX_PLANES]; + unsigned int plane_sizes[VIDEO_MAX_PLANES]; + + unsigned int streaming:1; + + struct vb2_fileio_data *fileio; +}; + +void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no); +void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no); + +void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state); +int vb2_wait_for_all_buffers(struct vb2_queue *q); + +int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b); +int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req); + +int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create); +int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b); + +int __must_check vb2_queue_init(struct vb2_queue *q); + +void vb2_queue_release(struct vb2_queue *q); + +int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b); +int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb); +int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking); + +int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type); +int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type); + +int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma); +#ifndef CONFIG_MMU +unsigned long vb2_get_unmapped_area(struct vb2_queue *q, + unsigned long addr, + unsigned long len, + unsigned long pgoff, + unsigned long flags); +#endif +unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait); +size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, + loff_t *ppos, int nonblock); +size_t vb2_write(struct vb2_queue *q, char __user *data, size_t count, + loff_t *ppos, int nonblock); + +/** + * vb2_is_streaming() - return streaming status of the queue + * @q: videobuf queue + */ +static inline bool vb2_is_streaming(struct vb2_queue *q) +{ + return q->streaming; +} + +/** + * vb2_is_busy() - return busy status of the queue + * @q: videobuf queue + * + * This function checks if queue has any buffers allocated. + */ +static inline bool vb2_is_busy(struct vb2_queue *q) +{ + return (q->num_buffers > 0); +} + +/** + * vb2_get_drv_priv() - return driver private data associated with the queue + * @q: videobuf queue + */ +static inline void *vb2_get_drv_priv(struct vb2_queue *q) +{ + return q->drv_priv; +} + +/** + * vb2_set_plane_payload() - set bytesused for the plane plane_no + * @vb: buffer for which plane payload should be set + * @plane_no: plane number for which payload should be set + * @size: payload in bytes + */ +static inline void vb2_set_plane_payload(struct vb2_buffer *vb, + unsigned int plane_no, unsigned long size) +{ + if (plane_no < vb->num_planes) + vb->v4l2_planes[plane_no].bytesused = size; +} + +/** + * vb2_get_plane_payload() - get bytesused for the plane plane_no + * @vb: buffer for which plane payload should be set + * @plane_no: plane number for which payload should be set + * @size: payload in bytes + */ +static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb, + unsigned int plane_no) +{ + if (plane_no < vb->num_planes) + return vb->v4l2_planes[plane_no].bytesused; + return 0; +} + +/** + * vb2_plane_size() - return plane size in bytes + * @vb: buffer for which plane size should be returned + * @plane_no: plane number for which size should be returned + */ +static inline unsigned long +vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no) +{ + if (plane_no < vb->num_planes) + return vb->v4l2_planes[plane_no].length; + return 0; +} + +/* + * The following functions are not part of the vb2 core API, but are simple + * helper functions that you can use in your struct v4l2_file_operations, + * struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock + * or video_device->lock is set, and they will set and test vb2_queue->owner + * to check if the calling filehandle is permitted to do the queuing operation. + */ + +/* struct v4l2_ioctl_ops helpers */ + +int vb2_ioctl_reqbufs(struct file *file, void *priv, + struct v4l2_requestbuffers *p); +int vb2_ioctl_create_bufs(struct file *file, void *priv, + struct v4l2_create_buffers *p); +int vb2_ioctl_prepare_buf(struct file *file, void *priv, + struct v4l2_buffer *p); +int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p); +int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p); +int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p); +int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i); +int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i); +int vb2_ioctl_expbuf(struct file *file, void *priv, + struct v4l2_exportbuffer *p); + +/* struct v4l2_file_operations helpers */ + +int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma); +int vb2_fop_release(struct file *file); +ssize_t vb2_fop_write(struct file *file, char __user *buf, + size_t count, loff_t *ppos); +ssize_t vb2_fop_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos); +unsigned int vb2_fop_poll(struct file *file, poll_table *wait); +#ifndef CONFIG_MMU +unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr, + unsigned long len, unsigned long pgoff, unsigned long flags); +#endif + +/* struct vb2_ops helpers, only use if vq->lock is non-NULL. */ + +void vb2_ops_wait_prepare(struct vb2_queue *vq); +void vb2_ops_wait_finish(struct vb2_queue *vq); + +#endif /* _MEDIA_VIDEOBUF2_CORE_H */ |