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Diffstat (limited to 'include/media/videobuf2-core.h')
| -rw-r--r-- | include/media/videobuf2-core.h | 1257 |
1 files changed, 1257 insertions, 0 deletions
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h new file mode 100644 index 000000000..bbb3f26fb --- /dev/null +++ b/include/media/videobuf2-core.h @@ -0,0 +1,1257 @@ +/* + * 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> + +#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_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. 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. 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 + * videobuf 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. + * @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. + * @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. + * + * 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 device *dev, unsigned long attrs, + 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)(struct device *dev, 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)(struct device *dev, + 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. + * @min_length: minimum required size of this plane (NOT the payload) in bytes. + * @length is always greater or equal to @min_length. + * @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 videobuf. + * @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_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. + * need_cache_sync_on_prepare: when set buffer's ->prepare() function + * performs cache sync/invalidation. + * need_cache_sync_on_finish: when set buffer's ->finish() function + * performs cache sync/invalidation. + * 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 + * vb2_plane: per-plane information; do not change + */ + enum vb2_buffer_state state; + unsigned int synced:1; + unsigned int prepared:1; + unsigned int copied_timestamp:1; + unsigned int need_cache_sync_on_prepare:1; + unsigned int need_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 + * q->num_buffers. 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. + * @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_buffers_needed. 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 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 (*start_streaming)(struct vb2_queue *q, unsigned int count); + void (*stop_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 videobuf 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). + * @alloc_devs: &struct device memory type/allocator-specific per-plane device + * @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(). + * @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_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 uAPI book): + * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped + * @memory: current memory type used + * @dma_dir: DMA mapping direction. + * @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 + * @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. + * @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 + * @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; + + 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_buffers_needed; + + 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[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; + + 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 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_start_streaming; + u32 cnt_stop_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 videobuf 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. + * @index: id number of the 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, unsigned int index, 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. + * @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 *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. + * @count: requested buffer count. + * @requested_planes: number of planes requested. + * @requested_sizes: array with the size of the planes. + * + * 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 *count, + unsigned int requested_planes, + const unsigned int requested_sizes[]); + +/** + * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace + * to the kernel. + * @q: pointer to &struct vb2_queue with videobuf2 queue. + * @index: id number of the 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, unsigned int index, void *pb); + +/** + * vb2_core_qbuf() - Queue a buffer from userspace + * + * @q: pointer to &struct vb2_queue with videobuf2 queue. + * @index: id number of the 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, unsigned int index, 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. + * @index: id number of the 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, + unsigned int index, 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_read() - 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_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->num_buffers > 0); +} + +/** + * 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) +{ + if (plane_no < vb->num_planes) + 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 (index < q->num_buffers) + 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 */ |