mirror of https://gitee.com/openkylin/linux.git
1827 lines
46 KiB
C
1827 lines
46 KiB
C
/*
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* videobuf2-core.c - V4L2 driver helper 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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* Marek Szyprowski <m.szyprowski@samsung.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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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/poll.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <media/videobuf2-core.h>
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static int debug;
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module_param(debug, int, 0644);
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#define dprintk(level, fmt, arg...) \
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do { \
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if (debug >= level) \
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printk(KERN_DEBUG "vb2: " fmt, ## arg); \
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} while (0)
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#define call_memop(q, plane, op, args...) \
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(((q)->mem_ops->op) ? \
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((q)->mem_ops->op(args)) : 0)
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#define call_qop(q, op, args...) \
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(((q)->ops->op) ? ((q)->ops->op(args)) : 0)
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#define V4L2_BUFFER_STATE_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
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V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR)
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/**
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* __vb2_buf_mem_alloc() - allocate video memory for the given buffer
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*/
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static int __vb2_buf_mem_alloc(struct vb2_buffer *vb,
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unsigned long *plane_sizes)
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{
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struct vb2_queue *q = vb->vb2_queue;
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void *mem_priv;
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int plane;
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/* Allocate memory for all planes in this buffer */
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for (plane = 0; plane < vb->num_planes; ++plane) {
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mem_priv = call_memop(q, plane, alloc, q->alloc_ctx[plane],
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plane_sizes[plane]);
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if (IS_ERR_OR_NULL(mem_priv))
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goto free;
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/* Associate allocator private data with this plane */
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vb->planes[plane].mem_priv = mem_priv;
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vb->v4l2_planes[plane].length = plane_sizes[plane];
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}
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return 0;
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free:
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/* Free already allocated memory if one of the allocations failed */
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for (; plane > 0; --plane)
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call_memop(q, plane, put, vb->planes[plane - 1].mem_priv);
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return -ENOMEM;
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}
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/**
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* __vb2_buf_mem_free() - free memory of the given buffer
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*/
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static void __vb2_buf_mem_free(struct vb2_buffer *vb)
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{
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struct vb2_queue *q = vb->vb2_queue;
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unsigned int plane;
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for (plane = 0; plane < vb->num_planes; ++plane) {
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call_memop(q, plane, put, vb->planes[plane].mem_priv);
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vb->planes[plane].mem_priv = NULL;
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dprintk(3, "Freed plane %d of buffer %d\n",
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plane, vb->v4l2_buf.index);
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}
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}
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/**
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* __vb2_buf_userptr_put() - release userspace memory associated with
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* a USERPTR buffer
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*/
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static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
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{
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struct vb2_queue *q = vb->vb2_queue;
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unsigned int plane;
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for (plane = 0; plane < vb->num_planes; ++plane) {
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void *mem_priv = vb->planes[plane].mem_priv;
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if (mem_priv) {
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call_memop(q, plane, put_userptr, mem_priv);
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vb->planes[plane].mem_priv = NULL;
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}
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}
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}
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/**
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* __setup_offsets() - setup unique offsets ("cookies") for every plane in
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* every buffer on the queue
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*/
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static void __setup_offsets(struct vb2_queue *q)
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{
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unsigned int buffer, plane;
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struct vb2_buffer *vb;
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unsigned long off = 0;
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for (buffer = 0; buffer < q->num_buffers; ++buffer) {
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vb = q->bufs[buffer];
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if (!vb)
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continue;
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for (plane = 0; plane < vb->num_planes; ++plane) {
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vb->v4l2_planes[plane].m.mem_offset = off;
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dprintk(3, "Buffer %d, plane %d offset 0x%08lx\n",
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buffer, plane, off);
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off += vb->v4l2_planes[plane].length;
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off = PAGE_ALIGN(off);
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}
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}
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}
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/**
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* __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
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* video buffer memory for all buffers/planes on the queue and initializes the
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* queue
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*
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* Returns the number of buffers successfully allocated.
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*/
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static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
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unsigned int num_buffers, unsigned int num_planes,
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unsigned long plane_sizes[])
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{
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unsigned int buffer;
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struct vb2_buffer *vb;
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int ret;
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for (buffer = 0; buffer < num_buffers; ++buffer) {
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/* Allocate videobuf buffer structures */
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vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
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if (!vb) {
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dprintk(1, "Memory alloc for buffer struct failed\n");
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break;
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}
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/* Length stores number of planes for multiplanar buffers */
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if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
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vb->v4l2_buf.length = num_planes;
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vb->state = VB2_BUF_STATE_DEQUEUED;
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vb->vb2_queue = q;
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vb->num_planes = num_planes;
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vb->v4l2_buf.index = buffer;
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vb->v4l2_buf.type = q->type;
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vb->v4l2_buf.memory = memory;
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/* Allocate video buffer memory for the MMAP type */
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if (memory == V4L2_MEMORY_MMAP) {
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ret = __vb2_buf_mem_alloc(vb, plane_sizes);
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if (ret) {
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dprintk(1, "Failed allocating memory for "
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"buffer %d\n", buffer);
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kfree(vb);
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break;
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}
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/*
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* Call the driver-provided buffer initialization
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* callback, if given. An error in initialization
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* results in queue setup failure.
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*/
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ret = call_qop(q, buf_init, vb);
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if (ret) {
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dprintk(1, "Buffer %d %p initialization"
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" failed\n", buffer, vb);
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__vb2_buf_mem_free(vb);
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kfree(vb);
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break;
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}
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}
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q->bufs[buffer] = vb;
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}
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q->num_buffers = buffer;
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__setup_offsets(q);
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dprintk(1, "Allocated %d buffers, %d plane(s) each\n",
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q->num_buffers, num_planes);
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return buffer;
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}
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/**
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* __vb2_free_mem() - release all video buffer memory for a given queue
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*/
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static void __vb2_free_mem(struct vb2_queue *q)
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{
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unsigned int buffer;
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struct vb2_buffer *vb;
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for (buffer = 0; buffer < q->num_buffers; ++buffer) {
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vb = q->bufs[buffer];
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if (!vb)
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continue;
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/* Free MMAP buffers or release USERPTR buffers */
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if (q->memory == V4L2_MEMORY_MMAP)
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__vb2_buf_mem_free(vb);
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else
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__vb2_buf_userptr_put(vb);
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}
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}
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/**
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* __vb2_queue_free() - free the queue - video memory and related information
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* and return the queue to an uninitialized state. Might be called even if the
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* queue has already been freed.
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*/
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static void __vb2_queue_free(struct vb2_queue *q)
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{
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unsigned int buffer;
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/* Call driver-provided cleanup function for each buffer, if provided */
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if (q->ops->buf_cleanup) {
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for (buffer = 0; buffer < q->num_buffers; ++buffer) {
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if (NULL == q->bufs[buffer])
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continue;
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q->ops->buf_cleanup(q->bufs[buffer]);
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}
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}
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/* Release video buffer memory */
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__vb2_free_mem(q);
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/* Free videobuf buffers */
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for (buffer = 0; buffer < q->num_buffers; ++buffer) {
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kfree(q->bufs[buffer]);
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q->bufs[buffer] = NULL;
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}
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q->num_buffers = 0;
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q->memory = 0;
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}
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/**
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* __verify_planes_array() - verify that the planes array passed in struct
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* v4l2_buffer from userspace can be safely used
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*/
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static int __verify_planes_array(struct vb2_buffer *vb, struct v4l2_buffer *b)
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{
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/* Is memory for copying plane information present? */
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if (NULL == b->m.planes) {
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dprintk(1, "Multi-planar buffer passed but "
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"planes array not provided\n");
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return -EINVAL;
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}
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if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
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dprintk(1, "Incorrect planes array length, "
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"expected %d, got %d\n", vb->num_planes, b->length);
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return -EINVAL;
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}
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return 0;
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}
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/**
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* __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
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* returned to userspace
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*/
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static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
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{
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struct vb2_queue *q = vb->vb2_queue;
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int ret = 0;
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/* Copy back data such as timestamp, flags, input, etc. */
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memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
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b->input = vb->v4l2_buf.input;
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b->reserved = vb->v4l2_buf.reserved;
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if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
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ret = __verify_planes_array(vb, b);
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if (ret)
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return ret;
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/*
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* Fill in plane-related data if userspace provided an array
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* for it. The memory and size is verified above.
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*/
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memcpy(b->m.planes, vb->v4l2_planes,
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b->length * sizeof(struct v4l2_plane));
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} else {
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/*
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* We use length and offset in v4l2_planes array even for
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* single-planar buffers, but userspace does not.
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*/
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b->length = vb->v4l2_planes[0].length;
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b->bytesused = vb->v4l2_planes[0].bytesused;
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if (q->memory == V4L2_MEMORY_MMAP)
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b->m.offset = vb->v4l2_planes[0].m.mem_offset;
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else if (q->memory == V4L2_MEMORY_USERPTR)
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b->m.userptr = vb->v4l2_planes[0].m.userptr;
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}
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/*
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* Clear any buffer state related flags.
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*/
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b->flags &= ~V4L2_BUFFER_STATE_FLAGS;
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switch (vb->state) {
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case VB2_BUF_STATE_QUEUED:
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case VB2_BUF_STATE_ACTIVE:
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b->flags |= V4L2_BUF_FLAG_QUEUED;
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break;
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case VB2_BUF_STATE_ERROR:
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b->flags |= V4L2_BUF_FLAG_ERROR;
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/* fall through */
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case VB2_BUF_STATE_DONE:
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b->flags |= V4L2_BUF_FLAG_DONE;
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break;
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case VB2_BUF_STATE_DEQUEUED:
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/* nothing */
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break;
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}
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if (vb->num_planes_mapped == vb->num_planes)
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b->flags |= V4L2_BUF_FLAG_MAPPED;
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return ret;
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}
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/**
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* vb2_querybuf() - query video buffer information
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* @q: videobuf queue
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* @b: buffer struct passed from userspace to vidioc_querybuf handler
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* in driver
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*
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* Should be called from vidioc_querybuf ioctl handler in driver.
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* This function will verify the passed v4l2_buffer structure and fill the
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* relevant information for the userspace.
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*
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* The return values from this function are intended to be directly returned
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* from vidioc_querybuf handler in driver.
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*/
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int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
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{
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struct vb2_buffer *vb;
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if (b->type != q->type) {
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dprintk(1, "querybuf: wrong buffer type\n");
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return -EINVAL;
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}
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if (b->index >= q->num_buffers) {
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dprintk(1, "querybuf: buffer index out of range\n");
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return -EINVAL;
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}
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vb = q->bufs[b->index];
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return __fill_v4l2_buffer(vb, b);
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}
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EXPORT_SYMBOL(vb2_querybuf);
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/**
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* __verify_userptr_ops() - verify that all memory operations required for
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* USERPTR queue type have been provided
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*/
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static int __verify_userptr_ops(struct vb2_queue *q)
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{
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if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
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!q->mem_ops->put_userptr)
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return -EINVAL;
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return 0;
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}
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/**
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* __verify_mmap_ops() - verify that all memory operations required for
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* MMAP queue type have been provided
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*/
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static int __verify_mmap_ops(struct vb2_queue *q)
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{
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if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
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!q->mem_ops->put || !q->mem_ops->mmap)
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return -EINVAL;
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return 0;
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}
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/**
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* __buffers_in_use() - return true if any buffers on the queue are in use and
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* the queue cannot be freed (by the means of REQBUFS(0)) call
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*/
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static bool __buffers_in_use(struct vb2_queue *q)
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{
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unsigned int buffer, plane;
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struct vb2_buffer *vb;
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for (buffer = 0; buffer < q->num_buffers; ++buffer) {
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vb = q->bufs[buffer];
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for (plane = 0; plane < vb->num_planes; ++plane) {
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/*
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* If num_users() has not been provided, call_memop
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* will return 0, apparently nobody cares about this
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* case anyway. If num_users() returns more than 1,
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* we are not the only user of the plane's memory.
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*/
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if (call_memop(q, plane, num_users,
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vb->planes[plane].mem_priv) > 1)
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return true;
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}
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}
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return false;
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}
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/**
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* vb2_reqbufs() - Initiate streaming
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* @q: videobuf2 queue
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* @req: struct passed from userspace to vidioc_reqbufs handler in driver
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*
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* Should be called from vidioc_reqbufs ioctl handler of a driver.
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* This function:
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* 1) verifies streaming parameters passed from the userspace,
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* 2) sets up the queue,
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* 3) negotiates number of buffers and planes per buffer with the driver
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* to be used during streaming,
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* 4) allocates internal buffer structures (struct vb2_buffer), according to
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* the agreed parameters,
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* 5) for MMAP memory type, allocates actual video memory, using the
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* memory handling/allocation routines provided during queue initialization
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*
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* If req->count is 0, all the memory will be freed instead.
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* If the queue has been allocated previously (by a previous vb2_reqbufs) call
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* and the queue is not busy, memory will be reallocated.
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*
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* The return values from this function are intended to be directly returned
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* from vidioc_reqbufs handler in driver.
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*/
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int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
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{
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unsigned int num_buffers, num_planes;
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unsigned long plane_sizes[VIDEO_MAX_PLANES];
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int ret = 0;
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if (q->fileio) {
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dprintk(1, "reqbufs: file io in progress\n");
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return -EBUSY;
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}
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if (req->memory != V4L2_MEMORY_MMAP
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&& req->memory != V4L2_MEMORY_USERPTR) {
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dprintk(1, "reqbufs: unsupported memory type\n");
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return -EINVAL;
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}
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if (req->type != q->type) {
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dprintk(1, "reqbufs: requested type is incorrect\n");
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return -EINVAL;
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}
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if (q->streaming) {
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dprintk(1, "reqbufs: streaming active\n");
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return -EBUSY;
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}
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|
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/*
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* Make sure all the required memory ops for given memory type
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* are available.
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*/
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if (req->memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
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dprintk(1, "reqbufs: MMAP for current setup unsupported\n");
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return -EINVAL;
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}
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if (req->memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
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dprintk(1, "reqbufs: USERPTR for current setup unsupported\n");
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return -EINVAL;
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}
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|
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/*
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* If the same number of buffers and memory access method is requested
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* then return immediately.
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*/
|
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if (q->memory == req->memory && req->count == q->num_buffers)
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return 0;
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|
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if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
|
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/*
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* We already have buffers allocated, so first check if they
|
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* are not in use and can be freed.
|
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*/
|
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if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
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dprintk(1, "reqbufs: memory in use, cannot free\n");
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return -EBUSY;
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|
}
|
|
|
|
__vb2_queue_free(q);
|
|
|
|
/*
|
|
* In case of REQBUFS(0) return immediately without calling
|
|
* driver's queue_setup() callback and allocating resources.
|
|
*/
|
|
if (req->count == 0)
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Make sure the requested values and current defaults are sane.
|
|
*/
|
|
num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
|
|
memset(plane_sizes, 0, sizeof(plane_sizes));
|
|
memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
|
|
q->memory = req->memory;
|
|
|
|
/*
|
|
* Ask the driver how many buffers and planes per buffer it requires.
|
|
* Driver also sets the size and allocator context for each plane.
|
|
*/
|
|
ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
|
|
plane_sizes, q->alloc_ctx);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Finally, allocate buffers and video memory */
|
|
ret = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes,
|
|
plane_sizes);
|
|
if (ret < 0) {
|
|
dprintk(1, "Memory allocation failed with error: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Check if driver can handle the allocated number of buffers.
|
|
*/
|
|
if (ret < num_buffers) {
|
|
unsigned int orig_num_buffers;
|
|
|
|
orig_num_buffers = num_buffers = ret;
|
|
ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
|
|
plane_sizes, q->alloc_ctx);
|
|
if (ret)
|
|
goto free_mem;
|
|
|
|
if (orig_num_buffers < num_buffers) {
|
|
ret = -ENOMEM;
|
|
goto free_mem;
|
|
}
|
|
|
|
/*
|
|
* Ok, driver accepted smaller number of buffers.
|
|
*/
|
|
ret = num_buffers;
|
|
}
|
|
|
|
/*
|
|
* Return the number of successfully allocated buffers
|
|
* to the userspace.
|
|
*/
|
|
req->count = ret;
|
|
|
|
return 0;
|
|
|
|
free_mem:
|
|
__vb2_queue_free(q);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_reqbufs);
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
struct vb2_queue *q = vb->vb2_queue;
|
|
|
|
if (plane_no > vb->num_planes)
|
|
return NULL;
|
|
|
|
return call_memop(q, plane_no, vaddr, vb->planes[plane_no].mem_priv);
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
struct vb2_queue *q = vb->vb2_queue;
|
|
|
|
if (plane_no > vb->num_planes)
|
|
return NULL;
|
|
|
|
return call_memop(q, plane_no, cookie, vb->planes[plane_no].mem_priv);
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_plane_cookie);
|
|
|
|
/**
|
|
* 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
|
|
* or VB2_BUF_STATE_ERROR if the operation finished with an error
|
|
*
|
|
* 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 buf_queue callback. Only buffers previously queued to the
|
|
* driver by buf_queue can be passed to this function.
|
|
*/
|
|
void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
|
|
{
|
|
struct vb2_queue *q = vb->vb2_queue;
|
|
unsigned long flags;
|
|
|
|
if (vb->state != VB2_BUF_STATE_ACTIVE)
|
|
return;
|
|
|
|
if (state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR)
|
|
return;
|
|
|
|
dprintk(4, "Done processing on buffer %d, state: %d\n",
|
|
vb->v4l2_buf.index, vb->state);
|
|
|
|
/* Add the buffer to the done buffers list */
|
|
spin_lock_irqsave(&q->done_lock, flags);
|
|
vb->state = state;
|
|
list_add_tail(&vb->done_entry, &q->done_list);
|
|
atomic_dec(&q->queued_count);
|
|
spin_unlock_irqrestore(&q->done_lock, flags);
|
|
|
|
/* Inform any processes that may be waiting for buffers */
|
|
wake_up(&q->done_wq);
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_buffer_done);
|
|
|
|
/**
|
|
* __fill_vb2_buffer() - fill a vb2_buffer with information provided in
|
|
* a v4l2_buffer by the userspace
|
|
*/
|
|
static int __fill_vb2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b,
|
|
struct v4l2_plane *v4l2_planes)
|
|
{
|
|
unsigned int plane;
|
|
int ret;
|
|
|
|
if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
|
|
/*
|
|
* Verify that the userspace gave us a valid array for
|
|
* plane information.
|
|
*/
|
|
ret = __verify_planes_array(vb, b);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Fill in driver-provided information for OUTPUT types */
|
|
if (V4L2_TYPE_IS_OUTPUT(b->type)) {
|
|
/*
|
|
* Will have to go up to b->length when API starts
|
|
* accepting variable number of planes.
|
|
*/
|
|
for (plane = 0; plane < vb->num_planes; ++plane) {
|
|
v4l2_planes[plane].bytesused =
|
|
b->m.planes[plane].bytesused;
|
|
v4l2_planes[plane].data_offset =
|
|
b->m.planes[plane].data_offset;
|
|
}
|
|
}
|
|
|
|
if (b->memory == V4L2_MEMORY_USERPTR) {
|
|
for (plane = 0; plane < vb->num_planes; ++plane) {
|
|
v4l2_planes[plane].m.userptr =
|
|
b->m.planes[plane].m.userptr;
|
|
v4l2_planes[plane].length =
|
|
b->m.planes[plane].length;
|
|
}
|
|
}
|
|
} else {
|
|
/*
|
|
* Single-planar buffers do not use planes array,
|
|
* so fill in relevant v4l2_buffer struct fields instead.
|
|
* In videobuf we use our internal V4l2_planes struct for
|
|
* single-planar buffers as well, for simplicity.
|
|
*/
|
|
if (V4L2_TYPE_IS_OUTPUT(b->type))
|
|
v4l2_planes[0].bytesused = b->bytesused;
|
|
|
|
if (b->memory == V4L2_MEMORY_USERPTR) {
|
|
v4l2_planes[0].m.userptr = b->m.userptr;
|
|
v4l2_planes[0].length = b->length;
|
|
}
|
|
}
|
|
|
|
vb->v4l2_buf.field = b->field;
|
|
vb->v4l2_buf.timestamp = b->timestamp;
|
|
vb->v4l2_buf.input = b->input;
|
|
vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_STATE_FLAGS;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* __qbuf_userptr() - handle qbuf of a USERPTR buffer
|
|
*/
|
|
static int __qbuf_userptr(struct vb2_buffer *vb, struct v4l2_buffer *b)
|
|
{
|
|
struct v4l2_plane planes[VIDEO_MAX_PLANES];
|
|
struct vb2_queue *q = vb->vb2_queue;
|
|
void *mem_priv;
|
|
unsigned int plane;
|
|
int ret;
|
|
int write = !V4L2_TYPE_IS_OUTPUT(q->type);
|
|
|
|
/* Verify and copy relevant information provided by the userspace */
|
|
ret = __fill_vb2_buffer(vb, b, planes);
|
|
if (ret)
|
|
return ret;
|
|
|
|
for (plane = 0; plane < vb->num_planes; ++plane) {
|
|
/* Skip the plane if already verified */
|
|
if (vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
|
|
&& vb->v4l2_planes[plane].length == planes[plane].length)
|
|
continue;
|
|
|
|
dprintk(3, "qbuf: userspace address for plane %d changed, "
|
|
"reacquiring memory\n", plane);
|
|
|
|
/* Release previously acquired memory if present */
|
|
if (vb->planes[plane].mem_priv)
|
|
call_memop(q, plane, put_userptr,
|
|
vb->planes[plane].mem_priv);
|
|
|
|
vb->planes[plane].mem_priv = NULL;
|
|
|
|
/* Acquire each plane's memory */
|
|
if (q->mem_ops->get_userptr) {
|
|
mem_priv = q->mem_ops->get_userptr(q->alloc_ctx[plane],
|
|
planes[plane].m.userptr,
|
|
planes[plane].length,
|
|
write);
|
|
if (IS_ERR(mem_priv)) {
|
|
dprintk(1, "qbuf: failed acquiring userspace "
|
|
"memory for plane %d\n", plane);
|
|
ret = PTR_ERR(mem_priv);
|
|
goto err;
|
|
}
|
|
vb->planes[plane].mem_priv = mem_priv;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Call driver-specific initialization on the newly acquired buffer,
|
|
* if provided.
|
|
*/
|
|
ret = call_qop(q, buf_init, vb);
|
|
if (ret) {
|
|
dprintk(1, "qbuf: buffer initialization failed\n");
|
|
goto err;
|
|
}
|
|
|
|
/*
|
|
* Now that everything is in order, copy relevant information
|
|
* provided by userspace.
|
|
*/
|
|
for (plane = 0; plane < vb->num_planes; ++plane)
|
|
vb->v4l2_planes[plane] = planes[plane];
|
|
|
|
return 0;
|
|
err:
|
|
/* In case of errors, release planes that were already acquired */
|
|
for (; plane > 0; --plane) {
|
|
call_memop(q, plane, put_userptr,
|
|
vb->planes[plane - 1].mem_priv);
|
|
vb->planes[plane - 1].mem_priv = NULL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* __qbuf_mmap() - handle qbuf of an MMAP buffer
|
|
*/
|
|
static int __qbuf_mmap(struct vb2_buffer *vb, struct v4l2_buffer *b)
|
|
{
|
|
return __fill_vb2_buffer(vb, b, vb->v4l2_planes);
|
|
}
|
|
|
|
/**
|
|
* __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
|
|
*/
|
|
static void __enqueue_in_driver(struct vb2_buffer *vb)
|
|
{
|
|
struct vb2_queue *q = vb->vb2_queue;
|
|
|
|
vb->state = VB2_BUF_STATE_ACTIVE;
|
|
atomic_inc(&q->queued_count);
|
|
q->ops->buf_queue(vb);
|
|
}
|
|
|
|
/**
|
|
* vb2_qbuf() - Queue a buffer from userspace
|
|
* @q: videobuf2 queue
|
|
* @b: buffer structure passed from userspace to vidioc_qbuf handler
|
|
* in driver
|
|
*
|
|
* Should be called from vidioc_qbuf ioctl handler of a driver.
|
|
* This function:
|
|
* 1) verifies the passed buffer,
|
|
* 2) calls buf_prepare callback in the driver (if provided), in which
|
|
* driver-specific buffer initialization can be performed,
|
|
* 3) if streaming is on, queues the buffer in driver by the means of 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_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
|
|
{
|
|
struct vb2_buffer *vb;
|
|
int ret = 0;
|
|
|
|
if (q->fileio) {
|
|
dprintk(1, "qbuf: file io in progress\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
if (b->type != q->type) {
|
|
dprintk(1, "qbuf: invalid buffer type\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (b->index >= q->num_buffers) {
|
|
dprintk(1, "qbuf: buffer index out of range\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
vb = q->bufs[b->index];
|
|
if (NULL == vb) {
|
|
/* Should never happen */
|
|
dprintk(1, "qbuf: buffer is NULL\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (b->memory != q->memory) {
|
|
dprintk(1, "qbuf: invalid memory type\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (vb->state != VB2_BUF_STATE_DEQUEUED) {
|
|
dprintk(1, "qbuf: buffer already in use\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (q->memory == V4L2_MEMORY_MMAP)
|
|
ret = __qbuf_mmap(vb, b);
|
|
else if (q->memory == V4L2_MEMORY_USERPTR)
|
|
ret = __qbuf_userptr(vb, b);
|
|
else {
|
|
WARN(1, "Invalid queue type\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = call_qop(q, buf_prepare, vb);
|
|
if (ret) {
|
|
dprintk(1, "qbuf: buffer preparation failed\n");
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Add to the queued buffers list, a buffer will stay on it until
|
|
* dequeued in dqbuf.
|
|
*/
|
|
list_add_tail(&vb->queued_entry, &q->queued_list);
|
|
vb->state = VB2_BUF_STATE_QUEUED;
|
|
|
|
/*
|
|
* If already streaming, give the buffer to driver for processing.
|
|
* If not, the buffer will be given to driver on next streamon.
|
|
*/
|
|
if (q->streaming)
|
|
__enqueue_in_driver(vb);
|
|
|
|
dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_qbuf);
|
|
|
|
/**
|
|
* __vb2_wait_for_done_vb() - wait for a buffer to become available
|
|
* for dequeuing
|
|
*
|
|
* Will sleep if required for nonblocking == false.
|
|
*/
|
|
static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
|
|
{
|
|
/*
|
|
* All operations on vb_done_list are performed under done_lock
|
|
* spinlock protection. However, buffers may be removed from
|
|
* it and returned to userspace only while holding both driver's
|
|
* lock and the done_lock spinlock. Thus we can be sure that as
|
|
* long as we hold the driver's lock, the list will remain not
|
|
* empty if list_empty() check succeeds.
|
|
*/
|
|
|
|
for (;;) {
|
|
int ret;
|
|
|
|
if (!q->streaming) {
|
|
dprintk(1, "Streaming off, will not wait for buffers\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!list_empty(&q->done_list)) {
|
|
/*
|
|
* Found a buffer that we were waiting for.
|
|
*/
|
|
break;
|
|
}
|
|
|
|
if (nonblocking) {
|
|
dprintk(1, "Nonblocking and no buffers to dequeue, "
|
|
"will not wait\n");
|
|
return -EAGAIN;
|
|
}
|
|
|
|
/*
|
|
* We are streaming and blocking, wait for another buffer to
|
|
* become ready or for streamoff. Driver's lock is released to
|
|
* allow streamoff or qbuf to be called while waiting.
|
|
*/
|
|
call_qop(q, wait_prepare, q);
|
|
|
|
/*
|
|
* All locks have been released, it is safe to sleep now.
|
|
*/
|
|
dprintk(3, "Will sleep waiting for buffers\n");
|
|
ret = wait_event_interruptible(q->done_wq,
|
|
!list_empty(&q->done_list) || !q->streaming);
|
|
|
|
/*
|
|
* We need to reevaluate both conditions again after reacquiring
|
|
* the locks or return an error if one occurred.
|
|
*/
|
|
call_qop(q, wait_finish, q);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* __vb2_get_done_vb() - get a buffer ready for dequeuing
|
|
*
|
|
* Will sleep if required for nonblocking == false.
|
|
*/
|
|
static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
|
|
int nonblocking)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
/*
|
|
* Wait for at least one buffer to become available on the done_list.
|
|
*/
|
|
ret = __vb2_wait_for_done_vb(q, nonblocking);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* Driver's lock has been held since we last verified that done_list
|
|
* is not empty, so no need for another list_empty(done_list) check.
|
|
*/
|
|
spin_lock_irqsave(&q->done_lock, flags);
|
|
*vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
|
|
list_del(&(*vb)->done_entry);
|
|
spin_unlock_irqrestore(&q->done_lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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 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 stop_streaming() callback.
|
|
*/
|
|
int vb2_wait_for_all_buffers(struct vb2_queue *q)
|
|
{
|
|
if (!q->streaming) {
|
|
dprintk(1, "Streaming off, will not wait for buffers\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
wait_event(q->done_wq, !atomic_read(&q->queued_count));
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
|
|
|
|
/**
|
|
* vb2_dqbuf() - Dequeue a buffer to the userspace
|
|
* @q: videobuf2 queue
|
|
* @b: 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.
|
|
* This function:
|
|
* 1) verifies the passed buffer,
|
|
* 2) 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,
|
|
* 3) 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_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
|
|
{
|
|
struct vb2_buffer *vb = NULL;
|
|
int ret;
|
|
|
|
if (q->fileio) {
|
|
dprintk(1, "dqbuf: file io in progress\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
if (b->type != q->type) {
|
|
dprintk(1, "dqbuf: invalid buffer type\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = __vb2_get_done_vb(q, &vb, nonblocking);
|
|
if (ret < 0) {
|
|
dprintk(1, "dqbuf: error getting next done buffer\n");
|
|
return ret;
|
|
}
|
|
|
|
ret = call_qop(q, buf_finish, vb);
|
|
if (ret) {
|
|
dprintk(1, "dqbuf: buffer finish failed\n");
|
|
return ret;
|
|
}
|
|
|
|
switch (vb->state) {
|
|
case VB2_BUF_STATE_DONE:
|
|
dprintk(3, "dqbuf: Returning done buffer\n");
|
|
break;
|
|
case VB2_BUF_STATE_ERROR:
|
|
dprintk(3, "dqbuf: Returning done buffer with errors\n");
|
|
break;
|
|
default:
|
|
dprintk(1, "dqbuf: Invalid buffer state\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Fill buffer information for the userspace */
|
|
__fill_v4l2_buffer(vb, b);
|
|
/* Remove from videobuf queue */
|
|
list_del(&vb->queued_entry);
|
|
|
|
dprintk(1, "dqbuf of buffer %d, with state %d\n",
|
|
vb->v4l2_buf.index, vb->state);
|
|
|
|
vb->state = VB2_BUF_STATE_DEQUEUED;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_dqbuf);
|
|
|
|
/**
|
|
* vb2_streamon - start streaming
|
|
* @q: videobuf2 queue
|
|
* @type: type argument passed from userspace to vidioc_streamon handler
|
|
*
|
|
* Should be called from vidioc_streamon handler of a driver.
|
|
* This function:
|
|
* 1) verifies current state
|
|
* 2) starts streaming and passes any previously queued buffers to the driver
|
|
*
|
|
* The return values from this function are intended to be directly returned
|
|
* from vidioc_streamon handler in the driver.
|
|
*/
|
|
int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
|
|
{
|
|
struct vb2_buffer *vb;
|
|
int ret;
|
|
|
|
if (q->fileio) {
|
|
dprintk(1, "streamon: file io in progress\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
if (type != q->type) {
|
|
dprintk(1, "streamon: invalid stream type\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (q->streaming) {
|
|
dprintk(1, "streamon: already streaming\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
/*
|
|
* Cannot start streaming on an OUTPUT device if no buffers have
|
|
* been queued yet.
|
|
*/
|
|
if (V4L2_TYPE_IS_OUTPUT(q->type)) {
|
|
if (list_empty(&q->queued_list)) {
|
|
dprintk(1, "streamon: no output buffers queued\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Let driver notice that streaming state has been enabled.
|
|
*/
|
|
ret = call_qop(q, start_streaming, q);
|
|
if (ret) {
|
|
dprintk(1, "streamon: driver refused to start streaming\n");
|
|
return ret;
|
|
}
|
|
|
|
q->streaming = 1;
|
|
|
|
/*
|
|
* If any buffers were queued before streamon,
|
|
* we can now pass them to driver for processing.
|
|
*/
|
|
list_for_each_entry(vb, &q->queued_list, queued_entry)
|
|
__enqueue_in_driver(vb);
|
|
|
|
dprintk(3, "Streamon successful\n");
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_streamon);
|
|
|
|
/**
|
|
* __vb2_queue_cancel() - cancel and stop (pause) streaming
|
|
*
|
|
* Removes all queued buffers from driver's queue and all buffers queued by
|
|
* userspace from videobuf's queue. Returns to state after reqbufs.
|
|
*/
|
|
static void __vb2_queue_cancel(struct vb2_queue *q)
|
|
{
|
|
unsigned int i;
|
|
|
|
/*
|
|
* Tell driver to stop all transactions and release all queued
|
|
* buffers.
|
|
*/
|
|
if (q->streaming)
|
|
call_qop(q, stop_streaming, q);
|
|
q->streaming = 0;
|
|
|
|
/*
|
|
* Remove all buffers from videobuf's list...
|
|
*/
|
|
INIT_LIST_HEAD(&q->queued_list);
|
|
/*
|
|
* ...and done list; userspace will not receive any buffers it
|
|
* has not already dequeued before initiating cancel.
|
|
*/
|
|
INIT_LIST_HEAD(&q->done_list);
|
|
wake_up_all(&q->done_wq);
|
|
|
|
/*
|
|
* Reinitialize all buffers for next use.
|
|
*/
|
|
for (i = 0; i < q->num_buffers; ++i)
|
|
q->bufs[i]->state = VB2_BUF_STATE_DEQUEUED;
|
|
}
|
|
|
|
/**
|
|
* vb2_streamoff - stop streaming
|
|
* @q: videobuf2 queue
|
|
* @type: type argument passed from userspace to vidioc_streamoff handler
|
|
*
|
|
* Should be called from vidioc_streamoff handler of a driver.
|
|
* This function:
|
|
* 1) verifies current state,
|
|
* 2) stop streaming and dequeues any queued buffers, including those previously
|
|
* passed to the driver (after waiting for the driver to finish).
|
|
*
|
|
* This call can be used for pausing playback.
|
|
* The return values from this function are intended to be directly returned
|
|
* from vidioc_streamoff handler in the driver
|
|
*/
|
|
int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
|
|
{
|
|
if (q->fileio) {
|
|
dprintk(1, "streamoff: file io in progress\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
if (type != q->type) {
|
|
dprintk(1, "streamoff: invalid stream type\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!q->streaming) {
|
|
dprintk(1, "streamoff: not streaming\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Cancel will pause streaming and remove all buffers from the driver
|
|
* and videobuf, effectively returning control over them to userspace.
|
|
*/
|
|
__vb2_queue_cancel(q);
|
|
|
|
dprintk(3, "Streamoff successful\n");
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_streamoff);
|
|
|
|
/**
|
|
* __find_plane_by_offset() - find plane associated with the given offset off
|
|
*/
|
|
static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
|
|
unsigned int *_buffer, unsigned int *_plane)
|
|
{
|
|
struct vb2_buffer *vb;
|
|
unsigned int buffer, plane;
|
|
|
|
/*
|
|
* Go over all buffers and their planes, comparing the given offset
|
|
* with an offset assigned to each plane. If a match is found,
|
|
* return its buffer and plane numbers.
|
|
*/
|
|
for (buffer = 0; buffer < q->num_buffers; ++buffer) {
|
|
vb = q->bufs[buffer];
|
|
|
|
for (plane = 0; plane < vb->num_planes; ++plane) {
|
|
if (vb->v4l2_planes[plane].m.mem_offset == off) {
|
|
*_buffer = buffer;
|
|
*_plane = plane;
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
|
|
struct vb2_plane *vb_plane;
|
|
struct vb2_buffer *vb;
|
|
unsigned int buffer, plane;
|
|
int ret;
|
|
|
|
if (q->memory != V4L2_MEMORY_MMAP) {
|
|
dprintk(1, "Queue is not currently set up for mmap\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Check memory area access mode.
|
|
*/
|
|
if (!(vma->vm_flags & VM_SHARED)) {
|
|
dprintk(1, "Invalid vma flags, VM_SHARED needed\n");
|
|
return -EINVAL;
|
|
}
|
|
if (V4L2_TYPE_IS_OUTPUT(q->type)) {
|
|
if (!(vma->vm_flags & VM_WRITE)) {
|
|
dprintk(1, "Invalid vma flags, VM_WRITE needed\n");
|
|
return -EINVAL;
|
|
}
|
|
} else {
|
|
if (!(vma->vm_flags & VM_READ)) {
|
|
dprintk(1, "Invalid vma flags, VM_READ needed\n");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Find the plane corresponding to the offset passed by userspace.
|
|
*/
|
|
ret = __find_plane_by_offset(q, off, &buffer, &plane);
|
|
if (ret)
|
|
return ret;
|
|
|
|
vb = q->bufs[buffer];
|
|
vb_plane = &vb->planes[plane];
|
|
|
|
ret = q->mem_ops->mmap(vb_plane->mem_priv, vma);
|
|
if (ret)
|
|
return ret;
|
|
|
|
vb_plane->mapped = 1;
|
|
vb->num_planes_mapped++;
|
|
|
|
dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_mmap);
|
|
|
|
static int __vb2_init_fileio(struct vb2_queue *q, int read);
|
|
static int __vb2_cleanup_fileio(struct vb2_queue *q);
|
|
|
|
/**
|
|
* vb2_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_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
|
|
{
|
|
unsigned long flags;
|
|
unsigned int ret;
|
|
struct vb2_buffer *vb = NULL;
|
|
|
|
/*
|
|
* Start file I/O emulator only if streaming API has not been used yet.
|
|
*/
|
|
if (q->num_buffers == 0 && q->fileio == NULL) {
|
|
if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ)) {
|
|
ret = __vb2_init_fileio(q, 1);
|
|
if (ret)
|
|
return POLLERR;
|
|
}
|
|
if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE)) {
|
|
ret = __vb2_init_fileio(q, 0);
|
|
if (ret)
|
|
return POLLERR;
|
|
/*
|
|
* Write to OUTPUT queue can be done immediately.
|
|
*/
|
|
return POLLOUT | POLLWRNORM;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* There is nothing to wait for if no buffers have already been queued.
|
|
*/
|
|
if (list_empty(&q->queued_list))
|
|
return POLLERR;
|
|
|
|
poll_wait(file, &q->done_wq, wait);
|
|
|
|
/*
|
|
* Take first buffer available for dequeuing.
|
|
*/
|
|
spin_lock_irqsave(&q->done_lock, flags);
|
|
if (!list_empty(&q->done_list))
|
|
vb = list_first_entry(&q->done_list, struct vb2_buffer,
|
|
done_entry);
|
|
spin_unlock_irqrestore(&q->done_lock, flags);
|
|
|
|
if (vb && (vb->state == VB2_BUF_STATE_DONE
|
|
|| vb->state == VB2_BUF_STATE_ERROR)) {
|
|
return (V4L2_TYPE_IS_OUTPUT(q->type)) ? POLLOUT | POLLWRNORM :
|
|
POLLIN | POLLRDNORM;
|
|
}
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_poll);
|
|
|
|
/**
|
|
* vb2_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_queue_init(struct vb2_queue *q)
|
|
{
|
|
BUG_ON(!q);
|
|
BUG_ON(!q->ops);
|
|
BUG_ON(!q->mem_ops);
|
|
BUG_ON(!q->type);
|
|
BUG_ON(!q->io_modes);
|
|
|
|
BUG_ON(!q->ops->queue_setup);
|
|
BUG_ON(!q->ops->buf_queue);
|
|
|
|
INIT_LIST_HEAD(&q->queued_list);
|
|
INIT_LIST_HEAD(&q->done_list);
|
|
spin_lock_init(&q->done_lock);
|
|
init_waitqueue_head(&q->done_wq);
|
|
|
|
if (q->buf_struct_size == 0)
|
|
q->buf_struct_size = sizeof(struct vb2_buffer);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_queue_init);
|
|
|
|
/**
|
|
* vb2_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_queue_release(struct vb2_queue *q)
|
|
{
|
|
__vb2_cleanup_fileio(q);
|
|
__vb2_queue_cancel(q);
|
|
__vb2_queue_free(q);
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_queue_release);
|
|
|
|
/**
|
|
* struct vb2_fileio_buf - buffer context used by file io emulator
|
|
*
|
|
* vb2 provides a compatibility layer and emulator of file io (read and
|
|
* write) calls on top of streaming API. This structure is used for
|
|
* tracking context related to the buffers.
|
|
*/
|
|
struct vb2_fileio_buf {
|
|
void *vaddr;
|
|
unsigned int size;
|
|
unsigned int pos;
|
|
unsigned int queued:1;
|
|
};
|
|
|
|
/**
|
|
* struct vb2_fileio_data - queue context used by file io emulator
|
|
*
|
|
* vb2 provides a compatibility layer and emulator of file io (read and
|
|
* write) calls on top of streaming API. For proper operation it required
|
|
* this structure to save the driver state between each call of the read
|
|
* or write function.
|
|
*/
|
|
struct vb2_fileio_data {
|
|
struct v4l2_requestbuffers req;
|
|
struct v4l2_buffer b;
|
|
struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
|
|
unsigned int index;
|
|
unsigned int q_count;
|
|
unsigned int dq_count;
|
|
unsigned int flags;
|
|
};
|
|
|
|
/**
|
|
* __vb2_init_fileio() - initialize file io emulator
|
|
* @q: videobuf2 queue
|
|
* @read: mode selector (1 means read, 0 means write)
|
|
*/
|
|
static int __vb2_init_fileio(struct vb2_queue *q, int read)
|
|
{
|
|
struct vb2_fileio_data *fileio;
|
|
int i, ret;
|
|
unsigned int count = 0;
|
|
|
|
/*
|
|
* Sanity check
|
|
*/
|
|
if ((read && !(q->io_modes & VB2_READ)) ||
|
|
(!read && !(q->io_modes & VB2_WRITE)))
|
|
BUG();
|
|
|
|
/*
|
|
* Check if device supports mapping buffers to kernel virtual space.
|
|
*/
|
|
if (!q->mem_ops->vaddr)
|
|
return -EBUSY;
|
|
|
|
/*
|
|
* Check if streaming api has not been already activated.
|
|
*/
|
|
if (q->streaming || q->num_buffers > 0)
|
|
return -EBUSY;
|
|
|
|
/*
|
|
* Start with count 1, driver can increase it in queue_setup()
|
|
*/
|
|
count = 1;
|
|
|
|
dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
|
|
(read) ? "read" : "write", count, q->io_flags);
|
|
|
|
fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
|
|
if (fileio == NULL)
|
|
return -ENOMEM;
|
|
|
|
fileio->flags = q->io_flags;
|
|
|
|
/*
|
|
* Request buffers and use MMAP type to force driver
|
|
* to allocate buffers by itself.
|
|
*/
|
|
fileio->req.count = count;
|
|
fileio->req.memory = V4L2_MEMORY_MMAP;
|
|
fileio->req.type = q->type;
|
|
ret = vb2_reqbufs(q, &fileio->req);
|
|
if (ret)
|
|
goto err_kfree;
|
|
|
|
/*
|
|
* Check if plane_count is correct
|
|
* (multiplane buffers are not supported).
|
|
*/
|
|
if (q->bufs[0]->num_planes != 1) {
|
|
fileio->req.count = 0;
|
|
ret = -EBUSY;
|
|
goto err_reqbufs;
|
|
}
|
|
|
|
/*
|
|
* Get kernel address of each buffer.
|
|
*/
|
|
for (i = 0; i < q->num_buffers; i++) {
|
|
fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
|
|
if (fileio->bufs[i].vaddr == NULL)
|
|
goto err_reqbufs;
|
|
fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
|
|
}
|
|
|
|
/*
|
|
* Read mode requires pre queuing of all buffers.
|
|
*/
|
|
if (read) {
|
|
/*
|
|
* Queue all buffers.
|
|
*/
|
|
for (i = 0; i < q->num_buffers; i++) {
|
|
struct v4l2_buffer *b = &fileio->b;
|
|
memset(b, 0, sizeof(*b));
|
|
b->type = q->type;
|
|
b->memory = q->memory;
|
|
b->index = i;
|
|
ret = vb2_qbuf(q, b);
|
|
if (ret)
|
|
goto err_reqbufs;
|
|
fileio->bufs[i].queued = 1;
|
|
}
|
|
|
|
/*
|
|
* Start streaming.
|
|
*/
|
|
ret = vb2_streamon(q, q->type);
|
|
if (ret)
|
|
goto err_reqbufs;
|
|
}
|
|
|
|
q->fileio = fileio;
|
|
|
|
return ret;
|
|
|
|
err_reqbufs:
|
|
vb2_reqbufs(q, &fileio->req);
|
|
|
|
err_kfree:
|
|
kfree(fileio);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* __vb2_cleanup_fileio() - free resourced used by file io emulator
|
|
* @q: videobuf2 queue
|
|
*/
|
|
static int __vb2_cleanup_fileio(struct vb2_queue *q)
|
|
{
|
|
struct vb2_fileio_data *fileio = q->fileio;
|
|
|
|
if (fileio) {
|
|
/*
|
|
* Hack fileio context to enable direct calls to vb2 ioctl
|
|
* interface.
|
|
*/
|
|
q->fileio = NULL;
|
|
|
|
vb2_streamoff(q, q->type);
|
|
fileio->req.count = 0;
|
|
vb2_reqbufs(q, &fileio->req);
|
|
kfree(fileio);
|
|
dprintk(3, "file io emulator closed\n");
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* __vb2_perform_fileio() - perform a single file io (read or write) operation
|
|
* @q: videobuf2 queue
|
|
* @data: pointed to target userspace buffer
|
|
* @count: number of bytes to read or write
|
|
* @ppos: file handle position tracking pointer
|
|
* @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
|
|
* @read: access mode selector (1 means read, 0 means write)
|
|
*/
|
|
static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
|
|
loff_t *ppos, int nonblock, int read)
|
|
{
|
|
struct vb2_fileio_data *fileio;
|
|
struct vb2_fileio_buf *buf;
|
|
int ret, index;
|
|
|
|
dprintk(3, "file io: mode %s, offset %ld, count %zd, %sblocking\n",
|
|
read ? "read" : "write", (long)*ppos, count,
|
|
nonblock ? "non" : "");
|
|
|
|
if (!data)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Initialize emulator on first call.
|
|
*/
|
|
if (!q->fileio) {
|
|
ret = __vb2_init_fileio(q, read);
|
|
dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
fileio = q->fileio;
|
|
|
|
/*
|
|
* Hack fileio context to enable direct calls to vb2 ioctl interface.
|
|
* The pointer will be restored before returning from this function.
|
|
*/
|
|
q->fileio = NULL;
|
|
|
|
index = fileio->index;
|
|
buf = &fileio->bufs[index];
|
|
|
|
/*
|
|
* Check if we need to dequeue the buffer.
|
|
*/
|
|
if (buf->queued) {
|
|
struct vb2_buffer *vb;
|
|
|
|
/*
|
|
* Call vb2_dqbuf to get buffer back.
|
|
*/
|
|
memset(&fileio->b, 0, sizeof(fileio->b));
|
|
fileio->b.type = q->type;
|
|
fileio->b.memory = q->memory;
|
|
fileio->b.index = index;
|
|
ret = vb2_dqbuf(q, &fileio->b, nonblock);
|
|
dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
|
|
if (ret)
|
|
goto end;
|
|
fileio->dq_count += 1;
|
|
|
|
/*
|
|
* Get number of bytes filled by the driver
|
|
*/
|
|
vb = q->bufs[index];
|
|
buf->size = vb2_get_plane_payload(vb, 0);
|
|
buf->queued = 0;
|
|
}
|
|
|
|
/*
|
|
* Limit count on last few bytes of the buffer.
|
|
*/
|
|
if (buf->pos + count > buf->size) {
|
|
count = buf->size - buf->pos;
|
|
dprintk(5, "reducing read count: %zd\n", count);
|
|
}
|
|
|
|
/*
|
|
* Transfer data to userspace.
|
|
*/
|
|
dprintk(3, "file io: copying %zd bytes - buffer %d, offset %u\n",
|
|
count, index, buf->pos);
|
|
if (read)
|
|
ret = copy_to_user(data, buf->vaddr + buf->pos, count);
|
|
else
|
|
ret = copy_from_user(buf->vaddr + buf->pos, data, count);
|
|
if (ret) {
|
|
dprintk(3, "file io: error copying data\n");
|
|
ret = -EFAULT;
|
|
goto end;
|
|
}
|
|
|
|
/*
|
|
* Update counters.
|
|
*/
|
|
buf->pos += count;
|
|
*ppos += count;
|
|
|
|
/*
|
|
* Queue next buffer if required.
|
|
*/
|
|
if (buf->pos == buf->size ||
|
|
(!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) {
|
|
/*
|
|
* Check if this is the last buffer to read.
|
|
*/
|
|
if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
|
|
fileio->dq_count == 1) {
|
|
dprintk(3, "file io: read limit reached\n");
|
|
/*
|
|
* Restore fileio pointer and release the context.
|
|
*/
|
|
q->fileio = fileio;
|
|
return __vb2_cleanup_fileio(q);
|
|
}
|
|
|
|
/*
|
|
* Call vb2_qbuf and give buffer to the driver.
|
|
*/
|
|
memset(&fileio->b, 0, sizeof(fileio->b));
|
|
fileio->b.type = q->type;
|
|
fileio->b.memory = q->memory;
|
|
fileio->b.index = index;
|
|
fileio->b.bytesused = buf->pos;
|
|
ret = vb2_qbuf(q, &fileio->b);
|
|
dprintk(5, "file io: vb2_dbuf result: %d\n", ret);
|
|
if (ret)
|
|
goto end;
|
|
|
|
/*
|
|
* Buffer has been queued, update the status
|
|
*/
|
|
buf->pos = 0;
|
|
buf->queued = 1;
|
|
buf->size = q->bufs[0]->v4l2_planes[0].length;
|
|
fileio->q_count += 1;
|
|
|
|
/*
|
|
* Switch to the next buffer
|
|
*/
|
|
fileio->index = (index + 1) % q->num_buffers;
|
|
|
|
/*
|
|
* Start streaming if required.
|
|
*/
|
|
if (!read && !q->streaming) {
|
|
ret = vb2_streamon(q, q->type);
|
|
if (ret)
|
|
goto end;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Return proper number of bytes processed.
|
|
*/
|
|
if (ret == 0)
|
|
ret = count;
|
|
end:
|
|
/*
|
|
* Restore the fileio context and block vb2 ioctl interface.
|
|
*/
|
|
q->fileio = fileio;
|
|
return ret;
|
|
}
|
|
|
|
size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
|
|
loff_t *ppos, int nonblocking)
|
|
{
|
|
return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_read);
|
|
|
|
size_t vb2_write(struct vb2_queue *q, char __user *data, size_t count,
|
|
loff_t *ppos, int nonblocking)
|
|
{
|
|
return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(vb2_write);
|
|
|
|
MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
|
|
MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
|
|
MODULE_LICENSE("GPL");
|