| /* |
| * videobuf2-core.h - Video Buffer 2 Core 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/dma-buf.h> |
| #include <linux/bitops.h> |
| #include <media/media-request.h> |
| #include <media/frame_vector.h> |
| |
| #define VB2_MAX_FRAME (32) |
| #define VB2_MAX_PLANES (8) |
| |
| /** |
| * enum vb2_memory - type of memory model used to make the buffers visible |
| * on userspace. |
| * |
| * @VB2_MEMORY_UNKNOWN: Buffer status is unknown or it is not used yet on |
| * userspace. |
| * @VB2_MEMORY_MMAP: The buffers are allocated by the Kernel and it is |
| * memory mapped via mmap() ioctl. This model is |
| * also used when the user is using the buffers via |
| * read() or write() system calls. |
| * @VB2_MEMORY_USERPTR: The buffers was allocated in userspace and it is |
| * memory mapped via mmap() ioctl. |
| * @VB2_MEMORY_DMABUF: The buffers are passed to userspace via DMA buffer. |
| */ |
| enum vb2_memory { |
| VB2_MEMORY_UNKNOWN = 0, |
| VB2_MEMORY_MMAP = 1, |
| VB2_MEMORY_USERPTR = 2, |
| VB2_MEMORY_DMABUF = 4, |
| }; |
| |
| struct vb2_fileio_data; |
| struct vb2_threadio_data; |
| struct vb2_buffer; |
| |
| /** |
| * struct vb2_mem_ops - memory handling/memory allocator operations. |
| * @alloc: allocate video memory and, optionally, allocator private data, |
| * return ERR_PTR() 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. The size argument to this function shall be |
| * *page aligned*. |
| * @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 |
| * videobuf2 layer when queuing a video buffer of USERPTR type; |
| * should return an allocator private per-buffer structure |
| * associated with the buffer on success, ERR_PTR() 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. |
| * @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. |
| * @attach_dmabuf: attach a shared &struct dma_buf for a hardware operation; |
| * used for DMABUF memory types; dev is the alloc device |
| * dbuf is the shared dma_buf; returns ERR_PTR() 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. |
| * @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 videobuf2 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. |
| * |
| * Those operations are used by the videobuf2 core to implement the memory |
| * handling/memory allocators for each type of supported streaming I/O method. |
| * |
| * .. note:: |
| * #) 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)(struct vb2_buffer *vb, |
| struct device *dev, |
| unsigned long size); |
| void (*put)(void *buf_priv); |
| struct dma_buf *(*get_dmabuf)(struct vb2_buffer *vb, |
| void *buf_priv, |
| unsigned long flags); |
| |
| void *(*get_userptr)(struct vb2_buffer *vb, |
| struct device *dev, |
| unsigned long vaddr, |
| unsigned long size); |
| void (*put_userptr)(void *buf_priv); |
| |
| void (*prepare)(void *buf_priv); |
| void (*finish)(void *buf_priv); |
| |
| void *(*attach_dmabuf)(struct vb2_buffer *vb, |
| struct device *dev, |
| struct dma_buf *dbuf, |
| unsigned long size); |
| void (*detach_dmabuf)(void *buf_priv); |
| int (*map_dmabuf)(void *buf_priv); |
| void (*unmap_dmabuf)(void *buf_priv); |
| |
| void *(*vaddr)(struct vb2_buffer *vb, void *buf_priv); |
| void *(*cookie)(struct vb2_buffer *vb, 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. The maximum |
| * valid size is MAX_UINT - PAGE_SIZE. |
| * @min_length: minimum required size of this plane (NOT the payload) in bytes. |
| * @length is always greater or equal to @min_length, and like |
| * @length, it is limited to MAX_UINT - PAGE_SIZE. |
| * @m: Union with memtype-specific data. |
| * @m.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). |
| * @m.userptr: when memory is %VB2_MEMORY_USERPTR, a userspace pointer |
| * pointing to this plane. |
| * @m.fd: when memory is %VB2_MEMORY_DMABUF, a userspace file |
| * descriptor associated with this plane. |
| * @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; |
| unsigned int min_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 = BIT(0), |
| VB2_USERPTR = BIT(1), |
| VB2_READ = BIT(2), |
| VB2_WRITE = BIT(3), |
| VB2_DMABUF = BIT(4), |
| }; |
| |
| /** |
| * enum vb2_buffer_state - current video buffer state. |
| * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control. |
| * @VB2_BUF_STATE_IN_REQUEST: buffer is queued in media request. |
| * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf2. |
| * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf2, 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 videobuf2, 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_IN_REQUEST, |
| VB2_BUF_STATE_PREPARING, |
| 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. |
| * @vb2_queue: pointer to &struct vb2_queue with 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. |
| * @timestamp: frame timestamp in ns. |
| * @request: the request this buffer is associated with. |
| * @req_obj: used to bind this buffer to a request. This |
| * request object has a refcount. |
| */ |
| struct vb2_buffer { |
| struct vb2_queue *vb2_queue; |
| unsigned int index; |
| unsigned int type; |
| unsigned int memory; |
| unsigned int num_planes; |
| u64 timestamp; |
| struct media_request *request; |
| struct media_request_object req_obj; |
| |
| /* private: internal use only |
| * |
| * state: current buffer state; do not change |
| * synced: this buffer has been synced for DMA, i.e. the |
| * 'prepare' memop was called. It is cleared again |
| * after the 'finish' memop is called. |
| * prepared: this buffer has been prepared, i.e. the |
| * buf_prepare op was called. It is cleared again |
| * after the 'buf_finish' op is called. |
| * copied_timestamp: the timestamp of this capture buffer was copied |
| * from an output buffer. |
| * skip_cache_sync_on_prepare: when set buffer's ->prepare() function |
| * skips cache sync/invalidation. |
| * skip_cache_sync_on_finish: when set buffer's ->finish() function |
| * skips cache sync/invalidation. |
| * planes: per-plane information; 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; |
| unsigned int synced:1; |
| unsigned int prepared:1; |
| unsigned int copied_timestamp:1; |
| unsigned int skip_cache_sync_on_prepare:1; |
| unsigned int skip_cache_sync_on_finish:1; |
| |
| struct vb2_plane planes[VB2_MAX_PLANES]; |
| 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_out_validate; |
| u32 cnt_buf_init; |
| u32 cnt_buf_prepare; |
| u32 cnt_buf_finish; |
| u32 cnt_buf_cleanup; |
| u32 cnt_buf_queue; |
| u32 cnt_buf_request_complete; |
| |
| /* This counts the number of calls to vb2_buffer_done() */ |
| u32 cnt_buf_done; |
| #endif |
| }; |
| |
| /** |
| * struct vb2_ops - driver-specific callbacks. |
| * |
| * These operations are not called from interrupt context except where |
| * mentioned specifically. |
| * |
| * @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 device in the alloc_devs\[\] 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. In this case |
| * \*num_buffers are being allocated additionally to |
| * the buffers already allocated. If either \*num_planes |
| * or the requested sizes are invalid callback must return %-EINVAL. |
| * @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_out_validate: called when the output buffer is prepared or queued |
| * to a request; drivers can use this to validate |
| * userspace-provided information; this is required only |
| * for OUTPUT queues. |
| * @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. |
| * @prepare_streaming: called once to prepare for 'streaming' state; this is |
| * where validation can be done to verify everything is |
| * okay and streaming resources can be claimed. It is |
| * called when the VIDIOC_STREAMON ioctl is called. The |
| * actual streaming starts when @start_streaming is called. |
| * 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() with %VB2_BUF_STATE_QUEUED. |
| * If you need a minimum number of buffers before you can |
| * start streaming, then set |
| * &vb2_queue->min_queued_buffers. 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 |
| * @unprepare_streaming:called as counterpart to @prepare_streaming; any claimed |
| * streaming resources can be released here. It is |
| * called when the VIDIOC_STREAMOFF ioctls is called or |
| * when the streaming filehandle is closed. Optional. |
| * @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 always called after calling VIDIOC_STREAMON() |
| * ioctl; might be called before @start_streaming callback |
| * if user pre-queued buffers before calling |
| * VIDIOC_STREAMON(). |
| * @buf_request_complete: a buffer that was never queued to the driver but is |
| * associated with a queued request was canceled. |
| * The driver will have to mark associated objects in the |
| * request as completed; required if requests are |
| * supported. |
| */ |
| struct vb2_ops { |
| int (*queue_setup)(struct vb2_queue *q, |
| unsigned int *num_buffers, unsigned int *num_planes, |
| unsigned int sizes[], struct device *alloc_devs[]); |
| |
| void (*wait_prepare)(struct vb2_queue *q); |
| void (*wait_finish)(struct vb2_queue *q); |
| |
| int (*buf_out_validate)(struct vb2_buffer *vb); |
| 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 (*prepare_streaming)(struct vb2_queue *q); |
| int (*start_streaming)(struct vb2_queue *q, unsigned int count); |
| void (*stop_streaming)(struct vb2_queue *q); |
| void (*unprepare_streaming)(struct vb2_queue *q); |
| |
| void (*buf_queue)(struct vb2_buffer *vb); |
| |
| void (*buf_request_complete)(struct vb2_buffer *vb); |
| }; |
| |
| /** |
| * struct vb2_buf_ops - driver-specific callbacks. |
| * |
| * @verify_planes_array: Verify that a given user space structure contains |
| * enough planes for the buffer. This is called |
| * for each dequeued buffer. |
| * @init_buffer: given a &vb2_buffer initialize the extra data after |
| * struct vb2_buffer. |
| * For V4L2 this is a &struct vb2_v4l2_buffer. |
| * @fill_user_buffer: given a &vb2_buffer fill in the userspace structure. |
| * For V4L2 this is a &struct v4l2_buffer. |
| * @fill_vb2_buffer: given a userspace structure, fill in the &vb2_buffer. |
| * If the userspace structure is invalid, then this op |
| * will return an error. |
| * @copy_timestamp: copy the timestamp from a userspace structure to |
| * the &struct vb2_buffer. |
| */ |
| struct vb2_buf_ops { |
| int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb); |
| void (*init_buffer)(struct vb2_buffer *vb); |
| void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb); |
| int (*fill_vb2_buffer)(struct vb2_buffer *vb, struct vb2_plane *planes); |
| void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb); |
| }; |
| |
| /** |
| * struct vb2_queue - a videobuf2 queue. |
| * |
| * @type: private buffer type whose content is defined by the vb2-core |
| * caller. For example, for V4L2, it should match |
| * the types defined on &enum v4l2_buf_type. |
| * @io_modes: supported io methods (see &enum vb2_io_modes). |
| * @dev: device to use for the default allocation context if the driver |
| * doesn't fill in the @alloc_devs array. |
| * @dma_attrs: DMA attributes to use for the DMA. |
| * @bidirectional: when this flag is set the DMA direction for the buffers of |
| * this queue will be overridden with %DMA_BIDIRECTIONAL direction. |
| * This is useful in cases where the hardware (firmware) writes to |
| * a buffer which is mapped as read (%DMA_TO_DEVICE), or reads from |
| * buffer which is mapped for write (%DMA_FROM_DEVICE) in order |
| * to satisfy some internal hardware restrictions or adds a padding |
| * needed by the processing algorithm. In case the DMA mapping is |
| * not bidirectional but the hardware (firmware) trying to access |
| * the buffer (in the opposite direction) this could lead to an |
| * IOMMU protection faults. |
| * @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 |
| * @quirk_poll_must_check_waiting_for_buffers: Return %EPOLLERR at poll when QBUF |
| * has not been called. This is a vb1 idiom that has been adopted |
| * also by vb2. |
| * @supports_requests: this queue supports the Request API. |
| * @requires_requests: this queue requires the Request API. If this is set to 1, |
| * then supports_requests must be set to 1 as well. |
| * @uses_qbuf: qbuf was used directly for this queue. Set to 1 the first |
| * time this is called. Set to 0 when the queue is canceled. |
| * If this is 1, then you cannot queue buffers from a request. |
| * @uses_requests: requests are used for this queue. Set to 1 the first time |
| * a request is queued. Set to 0 when the queue is canceled. |
| * If this is 1, then you cannot queue buffers directly. |
| * @allow_cache_hints: when set user-space can pass cache management hints in |
| * order to skip cache flush/invalidation on ->prepare() or/and |
| * ->finish(). |
| * @non_coherent_mem: when set queue will attempt to allocate buffers using |
| * non-coherent memory. |
| * @lock: pointer to a mutex that protects the &struct vb2_queue. 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. |
| * @subsystem_flags: Flags specific to the subsystem (V4L2/DVB/etc.). Not used |
| * by the vb2 core. |
| * @buf_struct_size: size of the driver-specific buffer structure; |
| * "0" indicates the driver doesn't want to use a custom buffer |
| * structure type. In that case a subsystem-specific struct |
| * will be used (in the case of V4L2 that is |
| * ``sizeof(struct vb2_v4l2_buffer)``). The first field of the |
| * driver-specific buffer structure must be the subsystem-specific |
| * struct (vb2_v4l2_buffer in the case of 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_queued_buffers: the minimum number of queued 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. |
| * VIDIOC_REQBUFS will ensure at least @min_queued_buffers + 1 |
| * buffers will be allocated. Note that VIDIOC_CREATE_BUFS will not |
| * modify the requested buffer count. |
| * @min_reqbufs_allocation: the minimum number of buffers to be allocated when |
| * calling VIDIOC_REQBUFS. Note that VIDIOC_CREATE_BUFS will *not* |
| * modify the requested buffer count and does not use this field. |
| * Drivers can set this if there has to be a certain number of |
| * buffers available for the hardware to work effectively. |
| * This allows calling VIDIOC_REQBUFS with a buffer count of 1 and |
| * it will be automatically adjusted to a workable buffer count. |
| * If set, then @min_reqbufs_allocation must be larger than |
| * @min_queued_buffers + 1. |
| * If this field is > 3, then it is highly recommended that the |
| * driver implements the V4L2_CID_MIN_BUFFERS_FOR_CAPTURE/OUTPUT |
| * control. |
| * @alloc_devs: &struct device memory type/allocator-specific per-plane device |
| */ |
| /* |
| * Private elements (won't appear at the uAPI book): |
| * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped |
| * @memory: current memory type used |
| * @dma_dir: DMA mapping direction. |
| * @bufs: videobuf2 buffer structures. If it is non-NULL then |
| * bufs_bitmap is also non-NULL. |
| * @bufs_bitmap: bitmap tracking whether each bufs[] entry is used |
| * @max_num_buffers: upper limit of number of allocated/used buffers. |
| * If set to 0 v4l2 core will change it VB2_MAX_FRAME |
| * for backward compatibility. |
| * @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 |
| * @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 %EPOLLERR in that situation. |
| * @waiting_in_dqbuf: set by the core for the duration of a blocking DQBUF, when |
| * it has to wait for a buffer to become available with vb2_queue->lock |
| * released. Used to prevent destroying the queue by other threads. |
| * @is_multiplanar: set if buffer type is multiplanar |
| * @is_output: set if buffer type is output |
| * @is_busy: set if at least one buffer has been allocated at some time. |
| * @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 |
| * @name: queue name, used for logging purpose. Initialized automatically |
| * if left empty by drivers. |
| */ |
| struct vb2_queue { |
| unsigned int type; |
| unsigned int io_modes; |
| struct device *dev; |
| unsigned long dma_attrs; |
| unsigned int bidirectional:1; |
| unsigned int fileio_read_once:1; |
| unsigned int fileio_write_immediately:1; |
| unsigned int allow_zero_bytesused:1; |
| unsigned int quirk_poll_must_check_waiting_for_buffers:1; |
| unsigned int supports_requests:1; |
| unsigned int requires_requests:1; |
| unsigned int uses_qbuf:1; |
| unsigned int uses_requests:1; |
| unsigned int allow_cache_hints:1; |
| unsigned int non_coherent_mem: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; |
| u32 subsystem_flags; |
| unsigned int buf_struct_size; |
| u32 timestamp_flags; |
| gfp_t gfp_flags; |
| u32 min_queued_buffers; |
| u32 min_reqbufs_allocation; |
| |
| struct device *alloc_devs[VB2_MAX_PLANES]; |
| |
| /* private: internal use only */ |
| struct mutex mmap_lock; |
| unsigned int memory; |
| enum dma_data_direction dma_dir; |
| struct vb2_buffer **bufs; |
| unsigned long *bufs_bitmap; |
| unsigned int max_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; |
| |
| unsigned int streaming:1; |
| unsigned int start_streaming_called:1; |
| unsigned int error:1; |
| unsigned int waiting_for_buffers:1; |
| unsigned int waiting_in_dqbuf:1; |
| unsigned int is_multiplanar:1; |
| unsigned int is_output:1; |
| unsigned int is_busy:1; |
| unsigned int copy_timestamp:1; |
| unsigned int last_buffer_dequeued:1; |
| |
| struct vb2_fileio_data *fileio; |
| struct vb2_threadio_data *threadio; |
| |
| char name[32]; |
| |
| #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_prepare_streaming; |
| u32 cnt_start_streaming; |
| u32 cnt_stop_streaming; |
| u32 cnt_unprepare_streaming; |
| #endif |
| }; |
| |
| /** |
| * vb2_queue_allows_cache_hints() - Return true if the queue allows cache |
| * and memory consistency hints. |
| * |
| * @q: pointer to &struct vb2_queue with videobuf2 queue |
| */ |
| static inline bool vb2_queue_allows_cache_hints(struct vb2_queue *q) |
| { |
| return q->allow_cache_hints && q->memory == VB2_MEMORY_MMAP; |
| } |
| |
| /** |
| * vb2_plane_vaddr() - Return a kernel virtual address of a given plane. |
| * @vb: pointer to &struct vb2_buffer to which the plane in |
| * question belongs to. |
| * @plane_no: plane number for which the address is to be returned. |
| * |
| * This function returns a kernel virtual address of a given plane if |
| * such a mapping exist, NULL otherwise. |
| */ |
| void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no); |
| |
| /** |
| * vb2_plane_cookie() - Return allocator specific cookie for the given plane. |
| * @vb: pointer to &struct vb2_buffer to which the plane in |
| * question belongs to. |
| * @plane_no: plane number for which the cookie is to be returned. |
| * |
| * This function returns an allocator specific cookie for a given plane if |
| * available, NULL otherwise. The allocator should provide some simple static |
| * inline function, which would convert this cookie to the allocator specific |
| * type that can be used directly by the driver to access the buffer. This can |
| * be for example physical address, pointer to scatter list or IOMMU mapping. |
| */ |
| void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no); |
| |
| /** |
| * vb2_buffer_done() - inform videobuf2 that an operation on a buffer |
| * is finished. |
| * @vb: pointer to &struct vb2_buffer to be used. |
| * @state: state of the buffer, as defined by &enum vb2_buffer_state. |
| * Either %VB2_BUF_STATE_DONE if the operation finished |
| * successfully, %VB2_BUF_STATE_ERROR if the operation finished |
| * with an error or %VB2_BUF_STATE_QUEUED. |
| * |
| * This function should be called by the driver after a hardware operation on |
| * a buffer is finished and the buffer may be returned to userspace. The driver |
| * cannot use this buffer anymore until it is queued back to it by videobuf |
| * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued |
| * to the driver by &vb2_ops->buf_queue can be passed to this function. |
| * |
| * While streaming a buffer can only be returned in state DONE or ERROR. |
| * The &vb2_ops->start_streaming op can also return them in case the DMA engine |
| * cannot be started for some reason. In that case the buffers should be |
| * returned with state QUEUED to put them back into the queue. |
| */ |
| void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state); |
| |
| /** |
| * vb2_discard_done() - discard all buffers marked as DONE. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * |
| * This function is intended to be used with suspend/resume operations. It |
| * discards all 'done' buffers as they would be too old to be requested after |
| * resume. |
| * |
| * Drivers must stop the hardware and synchronize with interrupt handlers and/or |
| * delayed works before calling this function to make sure no buffer will be |
| * touched by the driver and/or hardware. |
| */ |
| void vb2_discard_done(struct vb2_queue *q); |
| |
| /** |
| * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * |
| * This function will wait until all buffers that have been given to the driver |
| * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It |
| * doesn't call &vb2_ops->wait_prepare/&vb2_ops->wait_finish pair. |
| * It is intended to be called with all locks taken, for example from |
| * &vb2_ops->stop_streaming callback. |
| */ |
| int vb2_wait_for_all_buffers(struct vb2_queue *q); |
| |
| /** |
| * vb2_core_querybuf() - query video buffer information. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @vb: pointer to struct &vb2_buffer. |
| * @pb: buffer struct passed from userspace. |
| * |
| * Videobuf2 core helper to implement VIDIOC_QUERYBUF() operation. It is called |
| * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
| * |
| * The passed buffer should have been verified. |
| * |
| * This function fills the relevant information for the userspace. |
| * |
| * Return: returns zero on success; an error code otherwise. |
| */ |
| void vb2_core_querybuf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb); |
| |
| /** |
| * vb2_core_reqbufs() - Initiate streaming. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @memory: memory type, as defined by &enum vb2_memory. |
| * @flags: auxiliary queue/buffer management flags. Currently, the only |
| * used flag is %V4L2_MEMORY_FLAG_NON_COHERENT. |
| * @count: requested buffer count. |
| * |
| * Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called |
| * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
| * |
| * This function: |
| * |
| * #) verifies streaming parameters passed from the userspace; |
| * #) sets up the queue; |
| * #) negotiates number of buffers and planes per buffer with the driver |
| * to be used during streaming; |
| * #) allocates internal buffer structures (&struct vb2_buffer), according to |
| * the agreed parameters; |
| * #) for MMAP memory type, allocates actual video memory, using the |
| * memory handling/allocation routines provided during queue initialization. |
| * |
| * If req->count is 0, all the memory will be freed instead. |
| * |
| * If the queue has been allocated previously by a previous vb2_core_reqbufs() |
| * call and the queue is not busy, memory will be reallocated. |
| * |
| * Return: returns zero on success; an error code otherwise. |
| */ |
| int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, |
| unsigned int flags, unsigned int *count); |
| |
| /** |
| * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @memory: memory type, as defined by &enum vb2_memory. |
| * @flags: auxiliary queue/buffer management flags. |
| * @count: requested buffer count. |
| * @requested_planes: number of planes requested. |
| * @requested_sizes: array with the size of the planes. |
| * @first_index: index of the first created buffer, all allocated buffers have |
| * indices in the range [first_index..first_index+count-1] |
| * |
| * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is |
| * called internally by VB2 by an API-specific handler, like |
| * ``videobuf2-v4l2.h``. |
| * |
| * This function: |
| * |
| * #) verifies parameter sanity; |
| * #) calls the &vb2_ops->queue_setup queue operation; |
| * #) performs any necessary memory allocations. |
| * |
| * Return: returns zero on success; an error code otherwise. |
| */ |
| int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, |
| unsigned int flags, unsigned int *count, |
| unsigned int requested_planes, |
| const unsigned int requested_sizes[], |
| unsigned int *first_index); |
| |
| /** |
| * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace |
| * to the kernel. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @vb: pointer to struct &vb2_buffer. |
| * @pb: buffer structure passed from userspace to |
| * &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver. |
| * |
| * Videobuf2 core helper to implement VIDIOC_PREPARE_BUF() operation. It is |
| * called internally by VB2 by an API-specific handler, like |
| * ``videobuf2-v4l2.h``. |
| * |
| * The passed buffer should have been verified. |
| * |
| * This function calls vb2_ops->buf_prepare callback in the driver |
| * (if provided), in which driver-specific buffer initialization can |
| * be performed. |
| * |
| * Return: returns zero on success; an error code otherwise. |
| */ |
| int vb2_core_prepare_buf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb); |
| |
| /** |
| * vb2_core_remove_bufs() - |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @start: first index of the range of buffers to remove. |
| * @count: number of buffers to remove. |
| * |
| * Return: returns zero on success; an error code otherwise. |
| */ |
| int vb2_core_remove_bufs(struct vb2_queue *q, unsigned int start, unsigned int count); |
| |
| /** |
| * vb2_core_qbuf() - Queue a buffer from userspace |
| * |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @vb: pointer to struct &vb2_buffer. |
| * @pb: buffer structure passed from userspace to |
| * v4l2_ioctl_ops->vidioc_qbuf handler in driver |
| * @req: pointer to &struct media_request, may be NULL. |
| * |
| * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called |
| * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
| * |
| * This function: |
| * |
| * #) If @req is non-NULL, then the buffer will be bound to this |
| * media request and it returns. The buffer will be prepared and |
| * queued to the driver (i.e. the next two steps) when the request |
| * itself is queued. |
| * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver |
| * (if provided), in which driver-specific buffer initialization can |
| * be performed; |
| * #) if streaming is on, queues the buffer in driver by the means of |
| * &vb2_ops->buf_queue callback for processing. |
| * |
| * Return: returns zero on success; an error code otherwise. |
| */ |
| int vb2_core_qbuf(struct vb2_queue *q, struct vb2_buffer *vb, void *pb, |
| struct media_request *req); |
| |
| /** |
| * vb2_core_dqbuf() - Dequeue a buffer to the userspace |
| * @q: pointer to &struct vb2_queue with videobuf2 queue |
| * @pindex: pointer to the buffer index. May be NULL |
| * @pb: buffer structure passed from userspace to |
| * v4l2_ioctl_ops->vidioc_dqbuf handler in driver. |
| * @nonblocking: if true, this call will not sleep waiting for a buffer if no |
| * buffers ready for dequeuing are present. Normally the driver |
| * would be passing (file->f_flags & O_NONBLOCK) here. |
| * |
| * Videobuf2 core helper to implement VIDIOC_DQBUF() operation. It is called |
| * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
| * |
| * This function: |
| * |
| * #) calls buf_finish callback in the driver (if provided), in which |
| * driver can perform any additional operations that may be required before |
| * returning the buffer to userspace, such as cache sync, |
| * #) the buffer struct members are filled with relevant information for |
| * the userspace. |
| * |
| * Return: returns zero on success; an error code otherwise. |
| */ |
| int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb, |
| bool nonblocking); |
| |
| /** |
| * vb2_core_streamon() - Implements VB2 stream ON logic |
| * |
| * @q: pointer to &struct vb2_queue with videobuf2 queue |
| * @type: type of the queue to be started. |
| * For V4L2, this is defined by &enum v4l2_buf_type type. |
| * |
| * Videobuf2 core helper to implement VIDIOC_STREAMON() operation. It is called |
| * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
| * |
| * Return: returns zero on success; an error code otherwise. |
| */ |
| int vb2_core_streamon(struct vb2_queue *q, unsigned int type); |
| |
| /** |
| * vb2_core_streamoff() - Implements VB2 stream OFF logic |
| * |
| * @q: pointer to &struct vb2_queue with videobuf2 queue |
| * @type: type of the queue to be started. |
| * For V4L2, this is defined by &enum v4l2_buf_type type. |
| * |
| * Videobuf2 core helper to implement VIDIOC_STREAMOFF() operation. It is |
| * called internally by VB2 by an API-specific handler, like |
| * ``videobuf2-v4l2.h``. |
| * |
| * Return: returns zero on success; an error code otherwise. |
| */ |
| int vb2_core_streamoff(struct vb2_queue *q, unsigned int type); |
| |
| /** |
| * vb2_core_expbuf() - Export a buffer as a file descriptor. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @fd: pointer to the file descriptor associated with DMABUF |
| * (set by driver). |
| * @type: buffer type. |
| * @vb: pointer to struct &vb2_buffer. |
| * @plane: index of the plane to be exported, 0 for single plane queues |
| * @flags: file flags for newly created file, as defined at |
| * include/uapi/asm-generic/fcntl.h. |
| * Currently, the only used flag is %O_CLOEXEC. |
| * is supported, refer to manual of open syscall for more details. |
| * |
| * |
| * Videobuf2 core helper to implement VIDIOC_EXPBUF() operation. It is called |
| * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
| * |
| * Return: returns zero on success; an error code otherwise. |
| */ |
| int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, |
| struct vb2_buffer *vb, unsigned int plane, unsigned int flags); |
| |
| /** |
| * vb2_core_queue_init() - initialize a videobuf2 queue |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * This structure should be allocated in driver |
| * |
| * The &vb2_queue structure should be allocated by the driver. The driver is |
| * responsible of clearing it's content and setting initial values for some |
| * required entries before calling this function. |
| * |
| * .. note:: |
| * |
| * The following fields at @q should be set before calling this function: |
| * &vb2_queue->ops, &vb2_queue->mem_ops, &vb2_queue->type. |
| */ |
| int vb2_core_queue_init(struct vb2_queue *q); |
| |
| /** |
| * vb2_core_queue_release() - stop streaming, release the queue and free memory |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * |
| * This function stops streaming and performs necessary clean ups, including |
| * freeing video buffer memory. The driver is responsible for freeing |
| * the &struct vb2_queue itself. |
| */ |
| void vb2_core_queue_release(struct vb2_queue *q); |
| |
| /** |
| * vb2_queue_error() - signal a fatal error on the queue |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * |
| * Flag that a fatal unrecoverable error has occurred and wake up all processes |
| * waiting on the queue. Polling will now set %EPOLLERR and queuing and dequeuing |
| * buffers will return %-EIO. |
| * |
| * The error flag will be cleared when canceling the queue, either from |
| * vb2_streamoff() or vb2_queue_release(). Drivers should thus not call this |
| * function before starting the stream, otherwise the error flag will remain set |
| * until the queue is released when closing the device node. |
| */ |
| void vb2_queue_error(struct vb2_queue *q); |
| |
| /** |
| * vb2_mmap() - map video buffers into application address space. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @vma: pointer to &struct vm_area_struct with the vma passed |
| * to the mmap file operation handler in the driver. |
| * |
| * Should be called from mmap file operation handler of a driver. |
| * This function maps one plane of one of the available video buffers to |
| * userspace. To map whole video memory allocated on reqbufs, this function |
| * has to be called once per each plane per each buffer previously allocated. |
| * |
| * When the userspace application calls mmap, it passes to it an offset returned |
| * to it earlier by the means of &v4l2_ioctl_ops->vidioc_querybuf handler. |
| * That offset acts as a "cookie", which is then used to identify the plane |
| * to be mapped. |
| * |
| * This function finds a plane with a matching offset and a mapping is performed |
| * by the means of a provided memory operation. |
| * |
| * The return values from this function are intended to be directly returned |
| * from the mmap handler in driver. |
| */ |
| int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma); |
| |
| #ifndef CONFIG_MMU |
| /** |
| * vb2_get_unmapped_area - map video buffers into application address space. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @addr: memory address. |
| * @len: buffer size. |
| * @pgoff: page offset. |
| * @flags: memory flags. |
| * |
| * This function is used in noMMU platforms to propose address mapping |
| * for a given buffer. It's intended to be used as a handler for the |
| * &file_operations->get_unmapped_area operation. |
| * |
| * This is called by the mmap() syscall routines will call this |
| * to get a proposed address for the mapping, when ``!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_core_poll() - implements poll syscall() logic. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @file: &struct file argument passed to the poll |
| * file operation handler. |
| * @wait: &poll_table wait argument passed to the poll |
| * file operation handler. |
| * |
| * This function implements poll file operation handler for a driver. |
| * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will |
| * be informed that the file descriptor of a video device is available for |
| * reading. |
| * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor |
| * will be reported as available for writing. |
| * |
| * The return values from this function are intended to be directly returned |
| * from poll handler in driver. |
| */ |
| __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file, |
| poll_table *wait); |
| |
| /** |
| * vb2_read() - implements read() syscall logic. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @data: pointed to target userspace buffer |
| * @count: number of bytes to read |
| * @ppos: file handle position tracking pointer |
| * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) |
| */ |
| size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, |
| loff_t *ppos, int nonblock); |
| /** |
| * vb2_write() - implements write() syscall logic. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @data: pointed to target userspace buffer |
| * @count: number of bytes to write |
| * @ppos: file handle position tracking pointer |
| * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) |
| */ |
| size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, |
| loff_t *ppos, int nonblock); |
| |
| /** |
| * typedef vb2_thread_fnc - callback function for use with vb2_thread. |
| * |
| * @vb: pointer to struct &vb2_buffer. |
| * @priv: pointer to a private data. |
| * |
| * This is called whenever a buffer is dequeued in the thread. |
| */ |
| typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv); |
| |
| /** |
| * vb2_thread_start() - start a thread for the given queue. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @fnc: &vb2_thread_fnc callback function. |
| * @priv: priv pointer passed to the callback function. |
| * @thread_name:the name of the thread. This will be prefixed with "vb2-". |
| * |
| * This starts a thread that will queue and dequeue until an error occurs |
| * or vb2_thread_stop() is called. |
| * |
| * .. attention:: |
| * |
| * This function should not be used for anything else but the videobuf2-dvb |
| * support. If you think you have another good use-case for this, then please |
| * contact the linux-media mailing list first. |
| */ |
| int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv, |
| const char *thread_name); |
| |
| /** |
| * vb2_thread_stop() - stop the thread for the given queue. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| */ |
| int vb2_thread_stop(struct vb2_queue *q); |
| |
| /** |
| * vb2_is_streaming() - return streaming status of the queue. |
| * @q: pointer to &struct vb2_queue with videobuf2 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: pointer to &struct vb2_queue with videobuf2 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 &vb2_ops->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_get_num_buffers() - get the number of buffer in a queue |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| */ |
| static inline unsigned int vb2_get_num_buffers(struct vb2_queue *q) |
| { |
| if (q->bufs_bitmap) |
| return bitmap_weight(q->bufs_bitmap, q->max_num_buffers); |
| |
| return 0; |
| } |
| |
| /** |
| * vb2_is_busy() - return busy status of the queue. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * |
| * This function checks if queue has any buffers allocated. |
| */ |
| static inline bool vb2_is_busy(struct vb2_queue *q) |
| { |
| return !!q->is_busy; |
| } |
| |
| /** |
| * vb2_get_drv_priv() - return driver private data associated with the queue. |
| * @q: pointer to &struct vb2_queue with videobuf2 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: pointer to &struct vb2_buffer to which the plane in |
| * question belongs to. |
| * @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) |
| { |
| /* |
| * size must never be larger than the buffer length, so |
| * warn and clamp to the buffer length if that's the case. |
| */ |
| if (plane_no < vb->num_planes) { |
| if (WARN_ON_ONCE(size > vb->planes[plane_no].length)) |
| size = vb->planes[plane_no].length; |
| vb->planes[plane_no].bytesused = size; |
| } |
| } |
| |
| /** |
| * vb2_get_plane_payload() - get bytesused for the plane plane_no |
| * @vb: pointer to &struct vb2_buffer to which the plane in |
| * question belongs to. |
| * @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: pointer to &struct vb2_buffer to which the plane in |
| * question belongs to. |
| * @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: pointer to &struct vb2_queue with videobuf2 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: pointer to &struct vb2_queue with videobuf2 queue. |
| */ |
| static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q) |
| { |
| q->last_buffer_dequeued = false; |
| } |
| |
| /** |
| * vb2_get_buffer() - get a buffer from a queue |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @index: buffer index |
| * |
| * This function obtains a buffer from a queue, by its index. |
| * Keep in mind that there is no refcounting involved in this |
| * operation, so the buffer lifetime should be taken into |
| * consideration. |
| */ |
| static inline struct vb2_buffer *vb2_get_buffer(struct vb2_queue *q, |
| unsigned int index) |
| { |
| if (!q->bufs) |
| return NULL; |
| |
| if (index >= q->max_num_buffers) |
| return NULL; |
| |
| if (test_bit(index, q->bufs_bitmap)) |
| return q->bufs[index]; |
| return NULL; |
| } |
| |
| /* |
| * The following functions are not part of the vb2 core API, but are useful |
| * functions for videobuf2-*. |
| */ |
| |
| /** |
| * vb2_buffer_in_use() - return true if the buffer is in use and |
| * the queue cannot be freed (by the means of VIDIOC_REQBUFS(0)) call. |
| * |
| * @vb: buffer for which plane size should be returned. |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| */ |
| bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb); |
| |
| /** |
| * vb2_verify_memory_type() - Check whether the memory type and buffer type |
| * passed to a buffer operation are compatible with the queue. |
| * |
| * @q: pointer to &struct vb2_queue with videobuf2 queue. |
| * @memory: memory model, as defined by enum &vb2_memory. |
| * @type: private buffer type whose content is defined by the vb2-core |
| * caller. For example, for V4L2, it should match |
| * the types defined on enum &v4l2_buf_type. |
| */ |
| int vb2_verify_memory_type(struct vb2_queue *q, |
| enum vb2_memory memory, unsigned int type); |
| |
| /** |
| * vb2_request_object_is_buffer() - return true if the object is a buffer |
| * |
| * @obj: the request object. |
| */ |
| bool vb2_request_object_is_buffer(struct media_request_object *obj); |
| |
| /** |
| * vb2_request_buffer_cnt() - return the number of buffers in the request |
| * |
| * @req: the request. |
| */ |
| unsigned int vb2_request_buffer_cnt(struct media_request *req); |
| |
| #endif /* _MEDIA_VIDEOBUF2_CORE_H */ |