/* * videobuf2-core.h - Video Buffer 2 Core Framework * * Copyright (C) 2010 Samsung Electronics * * Author: Pawel Osciak * * 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 #include #include #include #define VB2_MAX_FRAME (32) #define VB2_MAX_PLANES (8) enum vb2_memory { VB2_MEMORY_UNKNOWN = 0, VB2_MEMORY_MMAP = 1, VB2_MEMORY_USERPTR = 2, VB2_MEMORY_DMABUF = 4, }; struct vb2_alloc_ctx; struct vb2_fileio_data; struct vb2_threadio_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_dmabuf: acquire userspace memory for a hardware operation; used for * DMABUF memory types. * @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, enum dma_data_direction dma_dir, gfp_t gfp_flags); void (*put)(void *buf_priv); struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags); void *(*get_userptr)(void *alloc_ctx, unsigned long vaddr, unsigned long size, enum dma_data_direction dma_dir); 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, enum dma_data_direction dma_dir); 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 - plane information * @mem_priv: private data with this plane * @dbuf: dma_buf - shared buffer object * @dbuf_mapped: flag to show whether dbuf is mapped or not * @bytesused: number of bytes occupied by data in the plane (payload) * @length: size of this plane (NOT the payload) in bytes * @offset: when memory in the associated struct vb2_buffer is * VB2_MEMORY_MMAP, equals the offset from the start of * the device memory for this plane (or is a "cookie" that * should be passed to mmap() called on the video node) * @userptr: when memory is VB2_MEMORY_USERPTR, a userspace pointer * pointing to this plane * @fd: when memory is VB2_MEMORY_DMABUF, a userspace file * descriptor associated with this plane * @m: Union with memtype-specific data (@offset, @userptr or * @fd). * @data_offset: offset in the plane to the start of data; usually 0, * unless there is a header in front of the data * Should contain enough information to be able to cover all the fields * of struct v4l2_plane at videodev2.h */ struct vb2_plane { void *mem_priv; struct dma_buf *dbuf; unsigned int dbuf_mapped; unsigned int bytesused; unsigned int length; union { unsigned int offset; unsigned long userptr; int fd; } m; unsigned int data_offset; }; /** * 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_buffer_state - current video buffer state * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf * @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_REQUEUEING: re-queue a buffer to the 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_PREPARING, VB2_BUF_STATE_PREPARED, VB2_BUF_STATE_QUEUED, VB2_BUF_STATE_REQUEUEING, VB2_BUF_STATE_ACTIVE, VB2_BUF_STATE_DONE, VB2_BUF_STATE_ERROR, }; struct vb2_queue; /** * struct vb2_buffer - represents a video buffer * @vb2_queue: the queue to which this driver belongs * @index: id number of the buffer * @type: buffer type * @memory: the method, in which the actual data is passed * @num_planes: number of planes in the buffer * on an internal driver queue * @planes: private per-plane information; do not change * @timestamp: frame timestamp in ns */ struct vb2_buffer { struct vb2_queue *vb2_queue; unsigned int index; unsigned int type; unsigned int memory; unsigned int num_planes; struct vb2_plane planes[VB2_MAX_PLANES]; u64 timestamp; /* private: internal use only * * 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 */ enum vb2_buffer_state state; struct list_head queued_entry; struct list_head done_entry; #ifdef CONFIG_VIDEO_ADV_DEBUG /* * Counters for how often these buffer-related ops are * called. Used to check for unbalanced ops. */ u32 cnt_mem_alloc; u32 cnt_mem_put; u32 cnt_mem_get_dmabuf; u32 cnt_mem_get_userptr; u32 cnt_mem_put_userptr; u32 cnt_mem_prepare; u32 cnt_mem_finish; u32 cnt_mem_attach_dmabuf; u32 cnt_mem_detach_dmabuf; u32 cnt_mem_map_dmabuf; u32 cnt_mem_unmap_dmabuf; u32 cnt_mem_vaddr; u32 cnt_mem_cookie; u32 cnt_mem_num_users; u32 cnt_mem_mmap; u32 cnt_buf_init; u32 cnt_buf_prepare; u32 cnt_buf_finish; u32 cnt_buf_cleanup; u32 cnt_buf_queue; /* This counts the number of calls to vb2_buffer_done() */ u32 cnt_buf_done; #endif }; /** * struct vb2_ops - driver-specific callbacks * * @queue_setup: called from VIDIOC_REQBUFS and VIDIOC_CREATE_BUFS * handlers before memory allocation. It can be called * twice: if the original number of requested buffers * could not be allocated, then it will be called a * second time with the actually allocated number of * buffers to verify if that is OK. * The 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, *num_planes == 0, the * driver has to use the currently configured format to * determine the plane sizes and *num_buffers is the total * number of buffers that are being allocated. When called * from VIDIOC_CREATE_BUFS, *num_planes != 0 and it * describes the requested number of planes and sizes[] * contains the requested plane sizes. If either * *num_planes or the requested sizes are invalid callback * must return -EINVAL. 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; drivers can * access/modify the buffer here as it is still synced for * the CPU; drivers that support VIDIOC_CREATE_BUFS must * also validate the buffer size; 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; the buffer is synced for the CPU, so drivers * can access/modify the buffer contents; drivers may * perform any operations required before userspace * accesses the buffer; optional. The buffer state can be * one of the following: DONE and ERROR occur while * streaming is in progress, and the PREPARED state occurs * when the queue has been canceled and all pending * buffers are being returned to their default DEQUEUED * state. Typically you only have to do something if the * state is VB2_BUF_STATE_DONE, since in all other cases * the buffer contents will be ignored anyway. * @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, in that case all * buffers that have been already given by the @buf_queue * callback are to be returned by the driver by calling * @vb2_buffer_done(VB2_BUF_STATE_QUEUED). * If you need a minimum number of buffers before you can * start streaming, then set @min_buffers_needed in the * vb2_queue structure. If that is non-zero then * start_streaming won't be called until at least that * many buffers have been queued up by userspace. * @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 by calling @vb2_buffer_done() with either * VB2_BUF_STATE_DONE or VB2_BUF_STATE_ERROR; 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, 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); void (*buf_finish)(struct vb2_buffer *vb); void (*buf_cleanup)(struct vb2_buffer *vb); int (*start_streaming)(struct vb2_queue *q, unsigned int count); void (*stop_streaming)(struct vb2_queue *q); void (*buf_queue)(struct vb2_buffer *vb); }; struct vb2_buf_ops { int (*fill_user_buffer)(struct vb2_buffer *vb, void *pb); int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb, struct vb2_plane *planes); int (*copy_timestamp)(struct vb2_buffer *vb, const void *pb); }; /** * struct vb2_queue - a videobuf queue * * @type: private buffer type whose content is defined by the vb2-core * caller. For example, for V4L2, it should match * the V4L2_BUF_TYPE_* in include/uapi/linux/videodev2.h * @io_modes: supported io methods (see vb2_io_modes enum) * @fileio_read_once: report EOF after reading the first buffer * @fileio_write_immediately: queue buffer after each write() call * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver * @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 * @buf_ops: callbacks to deliver buffer information * between user-space and kernel-space * @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. for example, sizeof(struct vb2_v4l2_buffer) * will be used for v4l2. * @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and * V4L2_BUF_FLAG_TSTAMP_SRC_* * @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. * @min_buffers_needed: the minimum number of buffers needed before * start_streaming() can be called. Used when a DMA engine * cannot be started unless at least this number of buffers * have been queued into the driver. */ /* * Private elements (won't appear at the DocBook): * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped * @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 queued and ready for streaming. * @owned_by_drv_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 * @start_streaming_called: start_streaming() was called successfully and we * started streaming. * @error: a fatal error occurred on the queue * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for * buffers. Only set for capture queues if qbuf has not yet been * called since poll() needs to return POLLERR in that situation. * @is_multiplanar: set if buffer type is multiplanar * @is_output: set if buffer type is output * @copy_timestamp: set if vb2-core should set timestamps * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the * last decoded buffer was already dequeued. Set for capture queues * when a buffer with the V4L2_BUF_FLAG_LAST is dequeued. * @fileio: file io emulator internal data, used only if emulator is active * @threadio: thread io internal data, used only if thread is active */ struct vb2_queue { unsigned int type; unsigned int io_modes; unsigned fileio_read_once:1; unsigned fileio_write_immediately:1; unsigned allow_zero_bytesused:1; struct mutex *lock; void *owner; const struct vb2_ops *ops; const struct vb2_mem_ops *mem_ops; const struct vb2_buf_ops *buf_ops; void *drv_priv; unsigned int buf_struct_size; u32 timestamp_flags; gfp_t gfp_flags; u32 min_buffers_needed; /* private: internal use only */ struct mutex mmap_lock; unsigned int memory; struct vb2_buffer *bufs[VB2_MAX_FRAME]; unsigned int num_buffers; struct list_head queued_list; unsigned int queued_count; atomic_t owned_by_drv_count; struct list_head done_list; spinlock_t done_lock; wait_queue_head_t done_wq; void *alloc_ctx[VB2_MAX_PLANES]; unsigned int plane_sizes[VB2_MAX_PLANES]; unsigned int streaming:1; unsigned int start_streaming_called:1; unsigned int error:1; unsigned int waiting_for_buffers:1; unsigned int is_multiplanar:1; unsigned int is_output:1; unsigned int copy_timestamp:1; unsigned int last_buffer_dequeued:1; struct vb2_fileio_data *fileio; struct vb2_threadio_data *threadio; #ifdef CONFIG_VIDEO_ADV_DEBUG /* * Counters for how often these queue-related ops are * called. Used to check for unbalanced ops. */ u32 cnt_queue_setup; u32 cnt_wait_prepare; u32 cnt_wait_finish; u32 cnt_start_streaming; u32 cnt_stop_streaming; #endif }; 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); void vb2_discard_done(struct vb2_queue *q); int vb2_wait_for_all_buffers(struct vb2_queue *q); int vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb); int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, unsigned int *count); int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, unsigned int *count, unsigned requested_planes, const unsigned int requested_sizes[]); int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb); int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb); int vb2_core_dqbuf(struct vb2_queue *q, void *pb, bool nonblocking); int vb2_core_streamon(struct vb2_queue *q, unsigned int type); int vb2_core_streamoff(struct vb2_queue *q, unsigned int type); int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, unsigned int index, unsigned int plane, unsigned int flags); int vb2_core_queue_init(struct vb2_queue *q); void vb2_core_queue_release(struct vb2_queue *q); void vb2_queue_error(struct vb2_queue *q); 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 /** * 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_fileio_is_active() - return true if fileio is active. * @q: videobuf queue * * This returns true if read() or write() is used to stream the data * as opposed to stream I/O. This is almost never an important distinction, * except in rare cases. One such case is that using read() or write() to * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there * is no way you can pass the field information of each buffer to/from * userspace. A driver that supports this field format should check for * this in the queue_setup op and reject it if this function returns true. */ static inline bool vb2_fileio_is_active(struct vb2_queue *q) { return q->fileio; } /** * 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->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 */ static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb, unsigned int plane_no) { if (plane_no < vb->num_planes) return vb->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->planes[plane_no].length; return 0; } /** * vb2_start_streaming_called() - return streaming status of driver * @q: videobuf queue */ static inline bool vb2_start_streaming_called(struct vb2_queue *q) { return q->start_streaming_called; } /** * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue * @q: videobuf queue */ static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q) { q->last_buffer_dequeued = false; } #endif /* _MEDIA_VIDEOBUF2_CORE_H */