![Stanimir Varbanov](/assets/img/avatar_default.png)
This change is intended to give to the v4l2 drivers a choice to change the default behavior of the v4l2-core DMA mapping direction from DMA_TO/FROM_DEVICE (depending on the buffer type CAPTURE or OUTPUT) to DMA_BIDIRECTIONAL during queue_init time. Initially the issue with DMA mapping direction has been found in Venus encoder driver where the hardware (firmware side) adds few lines padding on bottom of the image buffer, and the consequence is triggering of IOMMU protection faults. This will help supporting venus encoder (and probably other drivers in the future) which wants to map output type of buffers as read/write. Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Hans Verkuil <hansverk@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
1047 lines
40 KiB
C
1047 lines
40 KiB
C
/*
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* videobuf2-core.h - Video Buffer 2 Core Framework
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*
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* Copyright (C) 2010 Samsung Electronics
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*
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* Author: Pawel Osciak <pawel@osciak.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation.
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*/
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#ifndef _MEDIA_VIDEOBUF2_CORE_H
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#define _MEDIA_VIDEOBUF2_CORE_H
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#include <linux/mm_types.h>
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#include <linux/mutex.h>
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#include <linux/poll.h>
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#include <linux/dma-buf.h>
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#define VB2_MAX_FRAME (32)
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#define VB2_MAX_PLANES (8)
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/**
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* enum vb2_memory - type of memory model used to make the buffers visible
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* on userspace.
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*
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* @VB2_MEMORY_UNKNOWN: Buffer status is unknown or it is not used yet on
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* userspace.
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* @VB2_MEMORY_MMAP: The buffers are allocated by the Kernel and it is
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* memory mapped via mmap() ioctl. This model is
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* also used when the user is using the buffers via
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* read() or write() system calls.
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* @VB2_MEMORY_USERPTR: The buffers was allocated in userspace and it is
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* memory mapped via mmap() ioctl.
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* @VB2_MEMORY_DMABUF: The buffers are passed to userspace via DMA buffer.
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*/
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enum vb2_memory {
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VB2_MEMORY_UNKNOWN = 0,
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VB2_MEMORY_MMAP = 1,
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VB2_MEMORY_USERPTR = 2,
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VB2_MEMORY_DMABUF = 4,
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};
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struct vb2_fileio_data;
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struct vb2_threadio_data;
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/**
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* struct vb2_mem_ops - memory handling/memory allocator operations
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* @alloc: allocate video memory and, optionally, allocator private data,
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* return ERR_PTR() on failure or a pointer to allocator private,
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* per-buffer data on success; the returned private structure
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* will then be passed as @buf_priv argument to other ops in this
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* structure. Additional gfp_flags to use when allocating the
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* are also passed to this operation. These flags are from the
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* gfp_flags field of vb2_queue.
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* @put: inform the allocator that the buffer will no longer be used;
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* usually will result in the allocator freeing the buffer (if
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* no other users of this buffer are present); the @buf_priv
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* argument is the allocator private per-buffer structure
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* previously returned from the alloc callback.
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* @get_dmabuf: acquire userspace memory for a hardware operation; used for
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* DMABUF memory types.
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* @get_userptr: acquire userspace memory for a hardware operation; used for
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* USERPTR memory types; vaddr is the address passed to the
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* videobuf layer when queuing a video buffer of USERPTR type;
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* should return an allocator private per-buffer structure
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* associated with the buffer on success, ERR_PTR() on failure;
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* the returned private structure will then be passed as @buf_priv
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* argument to other ops in this structure.
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* @put_userptr: inform the allocator that a USERPTR buffer will no longer
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* be used.
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* @attach_dmabuf: attach a shared struct dma_buf for a hardware operation;
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* used for DMABUF memory types; dev is the alloc device
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* dbuf is the shared dma_buf; returns ERR_PTR() on failure;
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* allocator private per-buffer structure on success;
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* this needs to be used for further accesses to the buffer.
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* @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
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* buffer is no longer used; the @buf_priv argument is the
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* allocator private per-buffer structure previously returned
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* from the attach_dmabuf callback.
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* @map_dmabuf: request for access to the dmabuf from allocator; the allocator
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* of dmabuf is informed that this driver is going to use the
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* dmabuf.
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* @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
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* that this driver is done using the dmabuf for now.
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* @prepare: called every time the buffer is passed from userspace to the
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* driver, useful for cache synchronisation, optional.
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* @finish: called every time the buffer is passed back from the driver
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* to the userspace, also optional.
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* @vaddr: return a kernel virtual address to a given memory buffer
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* associated with the passed private structure or NULL if no
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* such mapping exists.
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* @cookie: return allocator specific cookie for a given memory buffer
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* associated with the passed private structure or NULL if not
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* available.
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* @num_users: return the current number of users of a memory buffer;
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* return 1 if the videobuf layer (or actually the driver using
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* it) is the only user.
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* @mmap: setup a userspace mapping for a given memory buffer under
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* the provided virtual memory region.
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*
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* Those operations are used by the videobuf2 core to implement the memory
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* handling/memory allocators for each type of supported streaming I/O method.
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*
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* .. note::
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* #) Required ops for USERPTR types: get_userptr, put_userptr.
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*
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* #) Required ops for MMAP types: alloc, put, num_users, mmap.
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*
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* #) Required ops for read/write access types: alloc, put, num_users, vaddr.
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*
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* #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf,
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* map_dmabuf, unmap_dmabuf.
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*/
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struct vb2_mem_ops {
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void *(*alloc)(struct device *dev, unsigned long attrs,
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unsigned long size,
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enum dma_data_direction dma_dir,
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gfp_t gfp_flags);
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void (*put)(void *buf_priv);
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struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
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void *(*get_userptr)(struct device *dev, unsigned long vaddr,
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unsigned long size,
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enum dma_data_direction dma_dir);
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void (*put_userptr)(void *buf_priv);
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void (*prepare)(void *buf_priv);
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void (*finish)(void *buf_priv);
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void *(*attach_dmabuf)(struct device *dev,
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struct dma_buf *dbuf,
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unsigned long size,
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enum dma_data_direction dma_dir);
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void (*detach_dmabuf)(void *buf_priv);
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int (*map_dmabuf)(void *buf_priv);
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void (*unmap_dmabuf)(void *buf_priv);
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void *(*vaddr)(void *buf_priv);
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void *(*cookie)(void *buf_priv);
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unsigned int (*num_users)(void *buf_priv);
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int (*mmap)(void *buf_priv, struct vm_area_struct *vma);
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};
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/**
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* struct vb2_plane - plane information
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* @mem_priv: private data with this plane
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* @dbuf: dma_buf - shared buffer object
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* @dbuf_mapped: flag to show whether dbuf is mapped or not
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* @bytesused: number of bytes occupied by data in the plane (payload)
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* @length: size of this plane (NOT the payload) in bytes
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* @min_length: minimum required size of this plane (NOT the payload) in bytes.
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* @length is always greater or equal to @min_length.
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* @offset: when memory in the associated struct vb2_buffer is
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* VB2_MEMORY_MMAP, equals the offset from the start of
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* the device memory for this plane (or is a "cookie" that
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* should be passed to mmap() called on the video node)
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* @userptr: when memory is VB2_MEMORY_USERPTR, a userspace pointer
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* pointing to this plane
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* @fd: when memory is VB2_MEMORY_DMABUF, a userspace file
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* descriptor associated with this plane
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* @m: Union with memtype-specific data (@offset, @userptr or
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* @fd).
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* @data_offset: offset in the plane to the start of data; usually 0,
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* unless there is a header in front of the data
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* Should contain enough information to be able to cover all the fields
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* of struct v4l2_plane at videodev2.h
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*/
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struct vb2_plane {
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void *mem_priv;
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struct dma_buf *dbuf;
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unsigned int dbuf_mapped;
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unsigned int bytesused;
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unsigned int length;
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unsigned int min_length;
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union {
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unsigned int offset;
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unsigned long userptr;
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int fd;
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} m;
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unsigned int data_offset;
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};
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/**
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* enum vb2_io_modes - queue access methods
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* @VB2_MMAP: driver supports MMAP with streaming API
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* @VB2_USERPTR: driver supports USERPTR with streaming API
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* @VB2_READ: driver supports read() style access
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* @VB2_WRITE: driver supports write() style access
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* @VB2_DMABUF: driver supports DMABUF with streaming API
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*/
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enum vb2_io_modes {
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VB2_MMAP = (1 << 0),
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VB2_USERPTR = (1 << 1),
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VB2_READ = (1 << 2),
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VB2_WRITE = (1 << 3),
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VB2_DMABUF = (1 << 4),
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};
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/**
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* enum vb2_buffer_state - current video buffer state
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* @VB2_BUF_STATE_DEQUEUED: buffer under userspace control
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* @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf
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* @VB2_BUF_STATE_PREPARED: buffer prepared in videobuf and by the driver
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* @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver
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* @VB2_BUF_STATE_REQUEUEING: re-queue a buffer to the driver
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* @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used
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* in a hardware operation
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* @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but
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* not yet dequeued to userspace
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* @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer
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* has ended with an error, which will be reported
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* to the userspace when it is dequeued
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*/
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enum vb2_buffer_state {
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VB2_BUF_STATE_DEQUEUED,
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VB2_BUF_STATE_PREPARING,
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VB2_BUF_STATE_PREPARED,
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VB2_BUF_STATE_QUEUED,
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VB2_BUF_STATE_REQUEUEING,
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VB2_BUF_STATE_ACTIVE,
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VB2_BUF_STATE_DONE,
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VB2_BUF_STATE_ERROR,
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};
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struct vb2_queue;
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/**
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* struct vb2_buffer - represents a video buffer
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* @vb2_queue: the queue to which this driver belongs
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* @index: id number of the buffer
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* @type: buffer type
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* @memory: the method, in which the actual data is passed
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* @num_planes: number of planes in the buffer
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* on an internal driver queue
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* @planes: private per-plane information; do not change
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* @timestamp: frame timestamp in ns
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*/
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struct vb2_buffer {
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struct vb2_queue *vb2_queue;
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unsigned int index;
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unsigned int type;
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unsigned int memory;
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unsigned int num_planes;
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struct vb2_plane planes[VB2_MAX_PLANES];
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u64 timestamp;
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/* private: internal use only
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*
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* state: current buffer state; do not change
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* queued_entry: entry on the queued buffers list, which holds
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* all buffers queued from userspace
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* done_entry: entry on the list that stores all buffers ready
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* to be dequeued to userspace
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*/
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enum vb2_buffer_state state;
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struct list_head queued_entry;
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struct list_head done_entry;
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#ifdef CONFIG_VIDEO_ADV_DEBUG
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/*
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* Counters for how often these buffer-related ops are
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* called. Used to check for unbalanced ops.
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*/
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u32 cnt_mem_alloc;
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u32 cnt_mem_put;
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u32 cnt_mem_get_dmabuf;
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u32 cnt_mem_get_userptr;
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u32 cnt_mem_put_userptr;
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u32 cnt_mem_prepare;
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u32 cnt_mem_finish;
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u32 cnt_mem_attach_dmabuf;
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u32 cnt_mem_detach_dmabuf;
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u32 cnt_mem_map_dmabuf;
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u32 cnt_mem_unmap_dmabuf;
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u32 cnt_mem_vaddr;
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u32 cnt_mem_cookie;
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u32 cnt_mem_num_users;
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u32 cnt_mem_mmap;
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u32 cnt_buf_init;
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u32 cnt_buf_prepare;
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u32 cnt_buf_finish;
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u32 cnt_buf_cleanup;
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u32 cnt_buf_queue;
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/* This counts the number of calls to vb2_buffer_done() */
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u32 cnt_buf_done;
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#endif
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};
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/**
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* struct vb2_ops - driver-specific callbacks
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*
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* @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS()
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* handlers before memory allocation. It can be called
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* twice: if the original number of requested buffers
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* could not be allocated, then it will be called a
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* second time with the actually allocated number of
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* buffers to verify if that is OK.
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* The driver should return the required number of buffers
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* in \*num_buffers, the required number of planes per
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* buffer in \*num_planes, the size of each plane should be
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* set in the sizes\[\] array and optional per-plane
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* allocator specific device in the alloc_devs\[\] array.
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* When called from VIDIOC_REQBUFS(), \*num_planes == 0,
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* the driver has to use the currently configured format to
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* determine the plane sizes and \*num_buffers is the total
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* number of buffers that are being allocated. When called
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* from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it
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* describes the requested number of planes and sizes\[\]
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* contains the requested plane sizes. In this case
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* \*num_buffers are being allocated additionally to
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* q->num_buffers. If either \*num_planes or the requested
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* sizes are invalid callback must return %-EINVAL.
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* @wait_prepare: release any locks taken while calling vb2 functions;
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* it is called before an ioctl needs to wait for a new
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* buffer to arrive; required to avoid a deadlock in
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* blocking access type.
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* @wait_finish: reacquire all locks released in the previous callback;
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* required to continue operation after sleeping while
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* waiting for a new buffer to arrive.
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* @buf_init: called once after allocating a buffer (in MMAP case)
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* or after acquiring a new USERPTR buffer; drivers may
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* perform additional buffer-related initialization;
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* initialization failure (return != 0) will prevent
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* queue setup from completing successfully; optional.
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* @buf_prepare: called every time the buffer is queued from userspace
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* and from the VIDIOC_PREPARE_BUF() ioctl; drivers may
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* perform any initialization required before each
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* hardware operation in this callback; drivers can
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* access/modify the buffer here as it is still synced for
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* the CPU; drivers that support VIDIOC_CREATE_BUFS() must
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* also validate the buffer size; if an error is returned,
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* the buffer will not be queued in driver; optional.
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* @buf_finish: called before every dequeue of the buffer back to
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* userspace; the buffer is synced for the CPU, so drivers
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* can access/modify the buffer contents; drivers may
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* perform any operations required before userspace
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* accesses the buffer; optional. The buffer state can be
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* one of the following: %DONE and %ERROR occur while
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* streaming is in progress, and the %PREPARED state occurs
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* when the queue has been canceled and all pending
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* buffers are being returned to their default %DEQUEUED
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* state. Typically you only have to do something if the
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* state is %VB2_BUF_STATE_DONE, since in all other cases
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* the buffer contents will be ignored anyway.
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* @buf_cleanup: called once before the buffer is freed; drivers may
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* perform any additional cleanup; optional.
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* @start_streaming: called once to enter 'streaming' state; the driver may
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* receive buffers with @buf_queue callback
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* before @start_streaming is called; the driver gets the
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* number of already queued buffers in count parameter;
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* driver can return an error if hardware fails, in that
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* case all buffers that have been already given by
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* the @buf_queue callback are to be returned by the driver
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* by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED.
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* If you need a minimum number of buffers before you can
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* start streaming, then set @min_buffers_needed in the
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* vb2_queue structure. If that is non-zero then
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* @start_streaming won't be called until at least that
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* many buffers have been queued up by userspace.
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* @stop_streaming: called when 'streaming' state must be disabled; driver
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* should stop any DMA transactions or wait until they
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* finish and give back all buffers it got from &buf_queue
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* callback by calling vb2_buffer_done() with either
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* %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
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* vb2_wait_for_all_buffers() function
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* @buf_queue: passes buffer vb to the driver; driver may start
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* hardware operation on this buffer; driver should give
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* the buffer back by calling vb2_buffer_done() function;
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* it is allways called after calling VIDIOC_STREAMON()
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* ioctl; might be called before @start_streaming callback
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* if user pre-queued buffers before calling
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* VIDIOC_STREAMON().
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*/
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struct vb2_ops {
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int (*queue_setup)(struct vb2_queue *q,
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unsigned int *num_buffers, unsigned int *num_planes,
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unsigned int sizes[], struct device *alloc_devs[]);
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void (*wait_prepare)(struct vb2_queue *q);
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void (*wait_finish)(struct vb2_queue *q);
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int (*buf_init)(struct vb2_buffer *vb);
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int (*buf_prepare)(struct vb2_buffer *vb);
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void (*buf_finish)(struct vb2_buffer *vb);
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void (*buf_cleanup)(struct vb2_buffer *vb);
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int (*start_streaming)(struct vb2_queue *q, unsigned int count);
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void (*stop_streaming)(struct vb2_queue *q);
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void (*buf_queue)(struct vb2_buffer *vb);
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};
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/**
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* struct vb2_buf_ops - driver-specific callbacks
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*
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* @verify_planes_array: Verify that a given user space structure contains
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* enough planes for the buffer. This is called
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* for each dequeued buffer.
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* @fill_user_buffer: given a vb2_buffer fill in the userspace structure.
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* For V4L2 this is a struct v4l2_buffer.
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* @fill_vb2_buffer: given a userspace structure, fill in the vb2_buffer.
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* If the userspace structure is invalid, then this op
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* will return an error.
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* @copy_timestamp: copy the timestamp from a userspace structure to
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* the vb2_buffer struct.
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*/
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struct vb2_buf_ops {
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int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
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void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
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int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb,
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struct vb2_plane *planes);
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void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
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};
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/**
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* struct vb2_queue - a videobuf queue
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*
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* @type: private buffer type whose content is defined by the vb2-core
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* caller. For example, for V4L2, it should match
|
|
* the types defined on enum &v4l2_buf_type
|
|
* @io_modes: supported io methods (see vb2_io_modes enum)
|
|
* @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 POLLERR at poll when QBUF
|
|
* has not been called. This is a vb1 idiom that has been adopted
|
|
* also by vb2.
|
|
* @lock: pointer to a mutex that protects the vb2_queue struct. The
|
|
* driver can set this to a mutex to let the v4l2 core serialize
|
|
* the queuing ioctls. If the driver wants to handle locking
|
|
* itself, then this should be set to NULL. This lock is not used
|
|
* by the videobuf2 core API.
|
|
* @owner: The filehandle that 'owns' the buffers, i.e. the filehandle
|
|
* that called reqbufs, create_buffers or started fileio.
|
|
* This field is not used by the videobuf2 core API, but it allows
|
|
* drivers to easily associate an owner filehandle with the queue.
|
|
* @ops: driver-specific callbacks
|
|
* @mem_ops: memory allocator specific callbacks
|
|
* @buf_ops: callbacks to deliver buffer information
|
|
* between user-space and kernel-space
|
|
* @drv_priv: driver private data
|
|
* @buf_struct_size: size of the driver-specific buffer structure;
|
|
* "0" indicates the driver doesn't want to use a custom buffer
|
|
* structure type. for example, sizeof(struct vb2_v4l2_buffer)
|
|
* will be used for v4l2.
|
|
* @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and
|
|
* V4L2_BUF_FLAG_TSTAMP_SRC_*
|
|
* @gfp_flags: additional gfp flags used when allocating the buffers.
|
|
* Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32
|
|
* to force the buffer allocation to a specific memory zone.
|
|
* @min_buffers_needed: the minimum number of buffers needed before
|
|
* @start_streaming can be called. Used when a DMA engine
|
|
* cannot be started unless at least this number of buffers
|
|
* have been queued into the driver.
|
|
*/
|
|
/*
|
|
* Private elements (won't appear at the 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
|
|
* @alloc_devs: memory type/allocator-specific per-plane device
|
|
* @streaming: current streaming state
|
|
* @start_streaming_called: @start_streaming was called successfully and we
|
|
* started streaming.
|
|
* @error: a fatal error occurred on the queue
|
|
* @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
|
|
* buffers. Only set for capture queues if qbuf has not yet been
|
|
* called since poll() needs to return POLLERR in that situation.
|
|
* @is_multiplanar: set if buffer type is multiplanar
|
|
* @is_output: set if buffer type is output
|
|
* @copy_timestamp: set if vb2-core should set timestamps
|
|
* @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
|
|
* last decoded buffer was already dequeued. Set for capture queues
|
|
* when a buffer with the V4L2_BUF_FLAG_LAST is dequeued.
|
|
* @fileio: file io emulator internal data, used only if emulator is active
|
|
* @threadio: thread io internal data, used only if thread is active
|
|
*/
|
|
struct vb2_queue {
|
|
unsigned int type;
|
|
unsigned int io_modes;
|
|
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;
|
|
|
|
struct mutex *lock;
|
|
void *owner;
|
|
|
|
const struct vb2_ops *ops;
|
|
const struct vb2_mem_ops *mem_ops;
|
|
const struct vb2_buf_ops *buf_ops;
|
|
|
|
void *drv_priv;
|
|
unsigned int buf_struct_size;
|
|
u32 timestamp_flags;
|
|
gfp_t gfp_flags;
|
|
u32 min_buffers_needed;
|
|
|
|
/* private: internal use only */
|
|
struct mutex mmap_lock;
|
|
unsigned int memory;
|
|
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;
|
|
|
|
struct device *alloc_devs[VB2_MAX_PLANES];
|
|
|
|
unsigned int streaming:1;
|
|
unsigned int start_streaming_called:1;
|
|
unsigned int error:1;
|
|
unsigned int waiting_for_buffers:1;
|
|
unsigned int is_multiplanar:1;
|
|
unsigned int is_output:1;
|
|
unsigned int copy_timestamp:1;
|
|
unsigned int last_buffer_dequeued:1;
|
|
|
|
struct vb2_fileio_data *fileio;
|
|
struct vb2_threadio_data *threadio;
|
|
|
|
#ifdef CONFIG_VIDEO_ADV_DEBUG
|
|
/*
|
|
* Counters for how often these queue-related ops are
|
|
* called. Used to check for unbalanced ops.
|
|
*/
|
|
u32 cnt_queue_setup;
|
|
u32 cnt_wait_prepare;
|
|
u32 cnt_wait_finish;
|
|
u32 cnt_start_streaming;
|
|
u32 cnt_stop_streaming;
|
|
#endif
|
|
};
|
|
|
|
/**
|
|
* vb2_plane_vaddr() - Return a kernel virtual address of a given plane
|
|
* @vb: 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: 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: vb2_buffer returned from the driver
|
|
* @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 if the driver wants to
|
|
* requeue buffers. If start_streaming fails then it should return
|
|
* buffers with state %VB2_BUF_STATE_QUEUED to put them back into
|
|
* the queue.
|
|
*
|
|
* 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 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.
|
|
*/
|
|
void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
|
|
|
|
/**
|
|
* vb2_discard_done() - discard all buffers marked as DONE
|
|
* @q: 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: 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 wait_prepare()/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: videobuf queue
|
|
* @index: id number of the buffer
|
|
* @pb: buffer struct passed from userspace
|
|
*
|
|
* Should be called from vidioc_querybuf ioctl handler in driver.
|
|
* The passed buffer should have been verified.
|
|
* This function fills the relevant information for the userspace.
|
|
*/
|
|
void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
|
|
|
|
/**
|
|
* vb2_core_reqbufs() - Initiate streaming
|
|
* @q: videobuf2 queue
|
|
* @memory: memory type
|
|
* @count: requested buffer count
|
|
*
|
|
* Should be called from vidioc_reqbufs ioctl handler of a driver.
|
|
*
|
|
* 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_reqbufs) call
|
|
* and the queue is not busy, memory will be reallocated.
|
|
*
|
|
* The return values from this function are intended to be directly returned
|
|
* from vidioc_reqbufs handler in driver.
|
|
*/
|
|
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: videobuf2 queue
|
|
* @memory: memory type
|
|
* @count: requested buffer count
|
|
* @requested_planes: number of planes requested
|
|
* @requested_sizes: array with the size of the planes
|
|
*
|
|
* Should be called from VIDIOC_CREATE_BUFS() ioctl handler of a driver.
|
|
* This function:
|
|
*
|
|
* #) verifies parameter sanity
|
|
* #) calls the .queue_setup() queue operation
|
|
* #) performs any necessary memory allocations
|
|
*
|
|
* Return: the return values from this function are intended to be directly
|
|
* returned from VIDIOC_CREATE_BUFS() handler in driver.
|
|
*/
|
|
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: videobuf2 queue
|
|
* @index: id number of the buffer
|
|
* @pb: buffer structure passed from userspace to vidioc_prepare_buf
|
|
* handler in driver
|
|
*
|
|
* Should be called from vidioc_prepare_buf ioctl handler of a driver.
|
|
* The passed buffer should have been verified.
|
|
* This function calls buf_prepare callback in the driver (if provided),
|
|
* in which driver-specific buffer initialization can be performed,
|
|
*
|
|
* The return values from this function are intended to be directly returned
|
|
* from vidioc_prepare_buf handler in driver.
|
|
*/
|
|
int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
|
|
|
|
/**
|
|
* vb2_core_qbuf() - Queue a buffer from userspace
|
|
*
|
|
* @q: videobuf2 queue
|
|
* @index: id number of the buffer
|
|
* @pb: buffer structure passed from userspace to vidioc_qbuf handler
|
|
* in driver
|
|
*
|
|
* Should be called from vidioc_qbuf ioctl handler of a driver.
|
|
* The passed buffer should have been verified.
|
|
*
|
|
* This function:
|
|
*
|
|
* #) if necessary, calls 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.
|
|
*
|
|
* The return values from this function are intended to be directly returned
|
|
* from vidioc_qbuf handler in driver.
|
|
*/
|
|
int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb);
|
|
|
|
/**
|
|
* vb2_core_dqbuf() - Dequeue a buffer to the userspace
|
|
* @q: videobuf2 queue
|
|
* @pindex: pointer to the buffer index. May be NULL
|
|
* @pb: buffer structure passed from userspace to 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
|
|
*
|
|
* Should be called from vidioc_dqbuf ioctl handler of a driver.
|
|
* The passed buffer should have been verified.
|
|
*
|
|
* 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.
|
|
*
|
|
* The return values from this function are intended to be directly returned
|
|
* from vidioc_dqbuf handler in driver.
|
|
*/
|
|
int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
|
|
bool nonblocking);
|
|
|
|
int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
|
|
int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
|
|
|
|
/**
|
|
* vb2_core_expbuf() - Export a buffer as a file descriptor
|
|
* @q: videobuf2 queue
|
|
* @fd: 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: flags for newly created file, currently only O_CLOEXEC is
|
|
* supported, refer to manual of open syscall for more details
|
|
*
|
|
* The return values from this function are intended to be directly returned
|
|
* from vidioc_expbuf handler in driver.
|
|
*/
|
|
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: 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.
|
|
* q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
|
|
* to the struct vb2_queue description in include/media/videobuf2-core.h
|
|
* for more information.
|
|
*/
|
|
int vb2_core_queue_init(struct vb2_queue *q);
|
|
|
|
/**
|
|
* vb2_core_queue_release() - stop streaming, release the queue and free memory
|
|
* @q: videobuf2 queue
|
|
*
|
|
* This function stops streaming and performs necessary clean ups, including
|
|
* freeing video buffer memory. The driver is responsible for freeing
|
|
* the vb2_queue structure itself.
|
|
*/
|
|
void vb2_core_queue_release(struct vb2_queue *q);
|
|
|
|
/**
|
|
* vb2_queue_error() - signal a fatal error on the queue
|
|
* @q: videobuf2 queue
|
|
*
|
|
* Flag that a fatal unrecoverable error has occurred and wake up all processes
|
|
* waiting on the queue. Polling will now set POLLERR and queuing and dequeuing
|
|
* buffers will return -EIO.
|
|
*
|
|
* The error flag will be cleared when cancelling 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: videobuf2 queue
|
|
* @vma: 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 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
|
|
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 userspace operation
|
|
* @q: videobuf2 queue
|
|
* @file: file argument passed to the poll file operation handler
|
|
* @wait: 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.
|
|
*/
|
|
unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
|
|
poll_table *wait);
|
|
|
|
size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
|
|
loff_t *ppos, int nonblock);
|
|
size_t vb2_write(struct vb2_queue *q, 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 pointer
|
|
*
|
|
* 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: videobuf queue
|
|
* @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: videobuf queue
|
|
*/
|
|
int vb2_thread_stop(struct vb2_queue *q);
|
|
|
|
/**
|
|
* vb2_is_streaming() - return streaming status of the queue
|
|
* @q: videobuf queue
|
|
*/
|
|
static inline bool vb2_is_streaming(struct vb2_queue *q)
|
|
{
|
|
return q->streaming;
|
|
}
|
|
|
|
/**
|
|
* vb2_fileio_is_active() - return true if fileio is active.
|
|
* @q: videobuf queue
|
|
*
|
|
* This returns true if read() or write() is used to stream the data
|
|
* as opposed to stream I/O. This is almost never an important distinction,
|
|
* except in rare cases. One such case is that using read() or write() to
|
|
* stream a format using V4L2_FIELD_ALTERNATE is not allowed since there
|
|
* is no way you can pass the field information of each buffer to/from
|
|
* userspace. A driver that supports this field format should check for
|
|
* this in the queue_setup op and reject it if this function returns true.
|
|
*/
|
|
static inline bool vb2_fileio_is_active(struct vb2_queue *q)
|
|
{
|
|
return q->fileio;
|
|
}
|
|
|
|
/**
|
|
* vb2_is_busy() - return busy status of the queue
|
|
* @q: videobuf queue
|
|
*
|
|
* This function checks if queue has any buffers allocated.
|
|
*/
|
|
static inline bool vb2_is_busy(struct vb2_queue *q)
|
|
{
|
|
return (q->num_buffers > 0);
|
|
}
|
|
|
|
/**
|
|
* vb2_get_drv_priv() - return driver private data associated with the queue
|
|
* @q: videobuf queue
|
|
*/
|
|
static inline void *vb2_get_drv_priv(struct vb2_queue *q)
|
|
{
|
|
return q->drv_priv;
|
|
}
|
|
|
|
/**
|
|
* vb2_set_plane_payload() - set bytesused for the plane plane_no
|
|
* @vb: buffer for which plane payload should be set
|
|
* @plane_no: plane number for which payload should be set
|
|
* @size: payload in bytes
|
|
*/
|
|
static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
|
|
unsigned int plane_no, unsigned long size)
|
|
{
|
|
if (plane_no < vb->num_planes)
|
|
vb->planes[plane_no].bytesused = size;
|
|
}
|
|
|
|
/**
|
|
* vb2_get_plane_payload() - get bytesused for the plane plane_no
|
|
* @vb: buffer for which plane payload should be set
|
|
* @plane_no: plane number for which payload should be set
|
|
*/
|
|
static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
|
|
unsigned int plane_no)
|
|
{
|
|
if (plane_no < vb->num_planes)
|
|
return vb->planes[plane_no].bytesused;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* vb2_plane_size() - return plane size in bytes
|
|
* @vb: buffer for which plane size should be returned
|
|
* @plane_no: plane number for which size should be returned
|
|
*/
|
|
static inline unsigned long
|
|
vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
|
|
{
|
|
if (plane_no < vb->num_planes)
|
|
return vb->planes[plane_no].length;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* vb2_start_streaming_called() - return streaming status of driver
|
|
* @q: videobuf queue
|
|
*/
|
|
static inline bool vb2_start_streaming_called(struct vb2_queue *q)
|
|
{
|
|
return q->start_streaming_called;
|
|
}
|
|
|
|
/**
|
|
* vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue
|
|
* @q: videobuf queue
|
|
*/
|
|
static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
|
|
{
|
|
q->last_buffer_dequeued = false;
|
|
}
|
|
|
|
/*
|
|
* 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 REQBUFS(0)) call
|
|
*
|
|
* @vb: buffer for which plane size should be returned
|
|
* @q: videobuf 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: videobuf 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);
|
|
#endif /* _MEDIA_VIDEOBUF2_CORE_H */
|