blob: 1168ed938f8ce9e285ac2bdd4a27d6f17360ec88 [file] [log] [blame]
/*
* 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 (64)
#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.
* 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;
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.
* @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.
* @buf_struct_size: size of the driver-specific buffer structure;
* "0" indicates the driver doesn't want to use a custom buffer
* structure type. for example, ``sizeof(struct vb2_v4l2_buffer)``
* will be used for v4l2.
* @timestamp_flags: Timestamp flags; ``V4L2_BUF_FLAG_TIMESTAMP_*`` and
* ``V4L2_BUF_FLAG_TSTAMP_SRC_*``
* @gfp_flags: additional gfp flags used when allocating the buffers.
* Typically this is 0, but it may be e.g. %GFP_DMA or %__GFP_DMA32
* to force the buffer allocation to a specific memory zone.
* @min_buffers_needed: the minimum number of buffers needed before
* @start_streaming can be called. Used when a DMA engine
* cannot be started unless at least this number of buffers
* have been queued into the driver.
*/
/*
* Private elements (won't appear at the 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
*/
struct vb2_queue {
unsigned int type;
unsigned int io_modes;
struct device *dev;
unsigned long dma_attrs;
unsigned bidirectional:1;
unsigned fileio_read_once:1;
unsigned fileio_write_immediately:1;
unsigned allow_zero_bytesused:1;
unsigned quirk_poll_must_check_waiting_for_buffers:1;
unsigned supports_requests:1;
unsigned requires_requests:1;
unsigned uses_qbuf:1;
unsigned uses_requests:1;
struct mutex *lock;
void *owner;
const struct vb2_ops *ops;
const struct vb2_mem_ops *mem_ops;
const struct vb2_buf_ops *buf_ops;
void *drv_priv;
unsigned int buf_struct_size;
u32 timestamp_flags;
gfp_t gfp_flags;
u32 min_buffers_needed;
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;
#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_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 */