- 根目录:
- drivers
- media
- v4l2-core
- videobuf2-v4l2.c
/*
* videobuf2-v4l2.c - V4L2 driver helper framework
*
* Copyright (C) 2010 Samsung Electronics
*
* Author: Pawel Osciak <pawel@osciak.com>
* Marek Szyprowski <m.szyprowski@samsung.com>
*
* The vb2_thread implementation was based on code from videobuf-dvb.c:
* (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation.
*/
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>
#include <media/v4l2-common.h>
#include <media/videobuf2-v4l2.h>
#include "videobuf2-internal.h"
/* Flags that are set by the vb2 core */
#define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
V4L2_BUF_FLAG_PREPARED | \
V4L2_BUF_FLAG_TIMESTAMP_MASK)
/* Output buffer flags that should be passed on to the driver */
#define V4L2_BUFFER_OUT_FLAGS (V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)
/**
* __verify_planes_array() - verify that the planes array passed in struct
* v4l2_buffer from userspace can be safely used
*/
static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
{
if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
return 0;
/* Is memory for copying plane information present? */
if (NULL == b->m.planes) {
dprintk(1, "multi-planar buffer passed but "
"planes array not provided\n");
return -EINVAL;
}
if (b->length < vb->num_planes || b->length > VB2_MAX_PLANES) {
dprintk(1, "incorrect planes array length, "
"expected %d, got %d\n", vb->num_planes, b->length);
return -EINVAL;
}
return 0;
}
/**
* __verify_length() - Verify that the bytesused value for each plane fits in
* the plane length and that the data offset doesn't exceed the bytesused value.
*/
static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
{
unsigned int length;
unsigned int bytesused;
unsigned int plane;
if (!V4L2_TYPE_IS_OUTPUT(b->type))
return 0;
if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
for (plane = 0; plane < vb->num_planes; ++plane) {
length = (b->memory == VB2_MEMORY_USERPTR ||
b->memory == VB2_MEMORY_DMABUF)
? b->m.planes[plane].length
: vb->planes[plane].length;
bytesused = b->m.planes[plane].bytesused
? b->m.planes[plane].bytesused : length;
if (b->m.planes[plane].bytesused > length)
return -EINVAL;
if (b->m.planes[plane].data_offset > 0 &&
b->m.planes[plane].data_offset >= bytesused)
return -EINVAL;
}
} else {
length = (b->memory == VB2_MEMORY_USERPTR)
? b->length : vb->planes[0].length;
if (b->bytesused > length)
return -EINVAL;
}
return 0;
}
static int __set_timestamp(struct vb2_buffer *vb, const void *pb)
{
const struct v4l2_buffer *b = pb;
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
struct vb2_queue *q = vb->vb2_queue;
if (q->is_output) {
/*
* For output buffers copy the timestamp if needed,
* and the timecode field and flag if needed.
*/
if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
V4L2_BUF_FLAG_TIMESTAMP_COPY)
vbuf->timestamp = b->timestamp;
vbuf->flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
if (b->flags & V4L2_BUF_FLAG_TIMECODE)
vbuf->timecode = b->timecode;
}
return 0;
};
static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
{
static bool check_once;
if (check_once)
return;
check_once = true;
WARN_ON(1);
pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");
if (vb->vb2_queue->allow_zero_bytesused)
pr_warn("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
else
pr_warn("use the actual size instead.\n");
}
static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
const char *opname)
{
if (b->type != q->type) {
dprintk(1, "%s: invalid buffer type\n", opname);
return -EINVAL;
}
if (b->index >= q->num_buffers) {
dprintk(1, "%s: buffer index out of range\n", opname);
return -EINVAL;
}
if (q->bufs[b->index] == NULL) {
/* Should never happen */
dprintk(1, "%s: buffer is NULL\n", opname);
return -EINVAL;
}
if (b->memory != q->memory) {
dprintk(1, "%s: invalid memory type\n", opname);
return -EINVAL;
}
return __verify_planes_array(q->bufs[b->index], b);
}
/**
* __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
* returned to userspace
*/
static int __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
{
struct v4l2_buffer *b = pb;
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
struct vb2_queue *q = vb->vb2_queue;
unsigned int plane;
/* Copy back data such as timestamp, flags, etc. */
b->index = vb->index;
b->type = vb->type;
b->memory = vb->memory;
b->bytesused = 0;
b->flags = vbuf->flags;
b->field = vbuf->field;
b->timestamp = vbuf->timestamp;
b->timecode = vbuf->timecode;
b->sequence = vbuf->sequence;
b->reserved2 = 0;
b->reserved = 0;
if (q->is_multiplanar) {
/*
* Fill in plane-related data if userspace provided an array
* for it. The caller has already verified memory and size.
*/
b->length = vb->num_planes;
for (plane = 0; plane < vb->num_planes; ++plane) {
struct v4l2_plane *pdst = &b->m.planes[plane];
struct vb2_plane *psrc = &vb->planes[plane];
pdst->bytesused = psrc->bytesused;
pdst->length = psrc->length;
if (q->memory == VB2_MEMORY_MMAP)
pdst->m.mem_offset = psrc->m.offset;
else if (q->memory == VB2_MEMORY_USERPTR)
pdst->m.userptr = psrc->m.userptr;
else if (q->memory == VB2_MEMORY_DMABUF)
pdst->m.fd = psrc->m.fd;
pdst->data_offset = psrc->data_offset;
memset(pdst->reserved, 0, sizeof(pdst->reserved));
}
} else {
/*
* We use length and offset in v4l2_planes array even for
* single-planar buffers, but userspace does not.
*/
b->length = vb->planes[0].length;
b->bytesused = vb->planes[0].bytesused;
if (q->memory == VB2_MEMORY_MMAP)
b->m.offset = vb->planes[0].m.offset;
else if (q->memory == VB2_MEMORY_USERPTR)
b->m.userptr = vb->planes[0].m.userptr;
else if (q->memory == VB2_MEMORY_DMABUF)
b->m.fd = vb->planes[0].m.fd;
}
/*
* Clear any buffer state related flags.
*/
b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
V4L2_BUF_FLAG_TIMESTAMP_COPY) {
/*
* For non-COPY timestamps, drop timestamp source bits
* and obtain the timestamp source from the queue.
*/
b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
}
switch (vb->state) {
case VB2_BUF_STATE_QUEUED:
case VB2_BUF_STATE_ACTIVE:
b->flags |= V4L2_BUF_FLAG_QUEUED;
break;
case VB2_BUF_STATE_ERROR:
b->flags |= V4L2_BUF_FLAG_ERROR;
/* fall through */
case VB2_BUF_STATE_DONE:
b->flags |= V4L2_BUF_FLAG_DONE;
break;
case VB2_BUF_STATE_PREPARED:
b->flags |= V4L2_BUF_FLAG_PREPARED;
break;
case VB2_BUF_STATE_PREPARING:
case VB2_BUF_STATE_DEQUEUED:
case VB2_BUF_STATE_REQUEUEING:
/* nothing */
break;
}
if (vb2_buffer_in_use(q, vb))
b->flags |= V4L2_BUF_FLAG_MAPPED;
return 0;
}
/**
* __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
* v4l2_buffer by the userspace. It also verifies that struct
* v4l2_buffer has a valid number of planes.
*/
static int __fill_vb2_buffer(struct vb2_buffer *vb,
const void *pb, struct vb2_plane *planes)
{
struct vb2_queue *q = vb->vb2_queue;
const struct v4l2_buffer *b = pb;
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
unsigned int plane;
int ret;
ret = __verify_length(vb, b);
if (ret < 0) {
dprintk(1, "plane parameters verification failed: %d\n", ret);
return ret;
}
if (b->field == V4L2_FIELD_ALTERNATE && q->is_output) {
/*
* If the format's field is ALTERNATE, then the buffer's field
* should be either TOP or BOTTOM, not ALTERNATE since that
* makes no sense. The driver has to know whether the
* buffer represents a top or a bottom field in order to
* program any DMA correctly. Using ALTERNATE is wrong, since
* that just says that it is either a top or a bottom field,
* but not which of the two it is.
*/
dprintk(1, "the field is incorrectly set to ALTERNATE "
"for an output buffer\n");
return -EINVAL;
}
vbuf->timestamp.tv_sec = 0;
vbuf->timestamp.tv_usec = 0;
vbuf->sequence = 0;
if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
if (b->memory == VB2_MEMORY_USERPTR) {
for (plane = 0; plane < vb->num_planes; ++plane) {
planes[plane].m.userptr =
b->m.planes[plane].m.userptr;
planes[plane].length =
b->m.planes[plane].length;
}
}
if (b->memory == VB2_MEMORY_DMABUF) {
for (plane = 0; plane < vb->num_planes; ++plane) {
planes[plane].m.fd =
b->m.planes[plane].m.fd;
planes[plane].length =
b->m.planes[plane].length;
}
}
/* 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.
*
* If bytesused == 0 for the output buffer, then fall
* back to the full buffer size. In that case
* userspace clearly never bothered to set it and
* it's a safe assumption that they really meant to
* use the full plane sizes.
*
* Some drivers, e.g. old codec drivers, use bytesused == 0
* as a way to indicate that streaming is finished.
* In that case, the driver should use the
* allow_zero_bytesused flag to keep old userspace
* applications working.
*/
for (plane = 0; plane < vb->num_planes; ++plane) {
struct vb2_plane *pdst = &planes[plane];
struct v4l2_plane *psrc = &b->m.planes[plane];
if (psrc->bytesused == 0)
vb2_warn_zero_bytesused(vb);
if (vb->vb2_queue->allow_zero_bytesused)
pdst->bytesused = psrc->bytesused;
else
pdst->bytesused = psrc->bytesused ?
psrc->bytesused : pdst->length;
pdst->data_offset = psrc->data_offset;
}
}
} 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 bytesused == 0 for the output buffer, then fall back
* to the full buffer size as that's a sensible default.
*
* Some drivers, e.g. old codec drivers, use bytesused == 0 as
* a way to indicate that streaming is finished. In that case,
* the driver should use the allow_zero_bytesused flag to keep
* old userspace applications working.
*/
if (b->memory == VB2_MEMORY_USERPTR) {
planes[0].m.userptr = b->m.userptr;
planes[0].length = b->length;
}
if (b->memory == VB2_MEMORY_DMABUF) {
planes[0].m.fd = b->m.fd;
planes[0].length = b->length;
}
if (V4L2_TYPE_IS_OUTPUT(b->type)) {
if (b->bytesused == 0)
vb2_warn_zero_bytesused(vb);
if (vb->vb2_queue->allow_zero_bytesused)
planes[0].bytesused = b->bytesused;
else
planes[0].bytesused = b->bytesused ?
b->bytesused : planes[0].length;
} else
planes[0].bytesused = 0;
}
/* Zero flags that the vb2 core handles */
vbuf->flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
if ((vb->vb2_queue->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) !=
V4L2_BUF_FLAG_TIMESTAMP_COPY || !V4L2_TYPE_IS_OUTPUT(b->type)) {
/*
* Non-COPY timestamps and non-OUTPUT queues will get
* their timestamp and timestamp source flags from the
* queue.
*/
vbuf->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
}
if (V4L2_TYPE_IS_OUTPUT(b->type)) {
/*
* For output buffers mask out the timecode flag:
* this will be handled later in vb2_internal_qbuf().
* The 'field' is valid metadata for this output buffer
* and so that needs to be copied here.
*/
vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE;
vbuf->field = b->field;
} else {
/* Zero any output buffer flags as this is a capture buffer */
vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS;
}
return 0;
}
static const struct vb2_buf_ops v4l2_buf_ops = {
.fill_user_buffer = __fill_v4l2_buffer,
.fill_vb2_buffer = __fill_vb2_buffer,
.set_timestamp = __set_timestamp,
};
/**
* vb2_querybuf() - query video buffer information
* @q: videobuf queue
* @b: buffer struct passed from userspace to vidioc_querybuf handler
* in driver
*
* Should be called from vidioc_querybuf ioctl handler in driver.
* This function will verify the passed v4l2_buffer structure and fill the
* relevant information for the userspace.
*
* The return values from this function are intended to be directly returned
* from vidioc_querybuf handler in driver.
*/
int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
{
struct vb2_buffer *vb;
int ret;
if (b->type != q->type) {
dprintk(1, "wrong buffer type\n");
return -EINVAL;
}
if (b->index >= q->num_buffers) {
dprintk(1, "buffer index out of range\n");
return -EINVAL;
}
vb = q->bufs[b->index];
ret = __verify_planes_array(vb, b);
return ret ? ret : vb2_core_querybuf(q, b->index, b);
}
EXPORT_SYMBOL(vb2_querybuf);
/**
* vb2_reqbufs() - Wrapper for vb2_core_reqbufs() that also verifies
* the memory and type values.
* @q: videobuf2 queue
* @req: struct passed from userspace to vidioc_reqbufs handler
* in driver
*/
int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
{
int ret = vb2_verify_memory_type(q, req->memory, req->type);
return ret ? ret : vb2_core_reqbufs(q, req->memory, &req->count);
}
EXPORT_SYMBOL_GPL(vb2_reqbufs);
/**
* vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
* @q: videobuf2 queue
* @b: buffer structure passed from userspace to vidioc_prepare_buf
* handler in driver
*
* Should be called from vidioc_prepare_buf 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,
*
* The return values from this function are intended to be directly returned
* from vidioc_prepare_buf handler in driver.
*/
int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
{
int ret;
if (vb2_fileio_is_active(q)) {
dprintk(1, "file io in progress\n");
return -EBUSY;
}
ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
return ret ? ret : vb2_core_prepare_buf(q, b->index, b);
}
EXPORT_SYMBOL_GPL(vb2_prepare_buf);
/**
* vb2_create_bufs() - Wrapper for vb2_core_create_bufs() that also verifies
* the memory and type values.
* @q: videobuf2 queue
* @create: creation parameters, passed from userspace to vidioc_create_bufs
* handler in driver
*/
int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
{
int ret = vb2_verify_memory_type(q, create->memory,
create->format.type);
create->index = q->num_buffers;
if (create->count == 0)
return ret != -EBUSY ? ret : 0;
return ret ? ret : vb2_core_create_bufs(q, create->memory,
&create->count, &create->format);
}
EXPORT_SYMBOL_GPL(vb2_create_bufs);
static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
{
int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
return ret ? ret : vb2_core_qbuf(q, b->index, b);
}
/**
* 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) if necessary, 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)
{
if (vb2_fileio_is_active(q)) {
dprintk(1, "file io in progress\n");
return -EBUSY;
}
return vb2_internal_qbuf(q, b);
}
EXPORT_SYMBOL_GPL(vb2_qbuf);
static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b,
bool nonblocking)
{
int ret;
if (b->type != q->type) {
dprintk(1, "invalid buffer type\n");
return -EINVAL;
}
ret = vb2_core_dqbuf(q, b, nonblocking);
if (!ret && !q->is_output &&
b->flags & V4L2_BUF_FLAG_LAST)
q->last_buffer_dequeued = true;
return ret;
}
/**
* 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)
{
if (vb2_fileio_is_active(q)) {
dprintk(1, "file io in progress\n");
return -EBUSY;
}
return vb2_internal_dqbuf(q, b, nonblocking);
}
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) passes any previously queued buffers to the driver and starts streaming
*
* 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)
{
if (vb2_fileio_is_active(q)) {
dprintk(1, "file io in progress\n");
return -EBUSY;
}
return vb2_core_streamon(q, type);
}
EXPORT_SYMBOL_GPL(vb2_streamon);
/**
* 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 (vb2_fileio_is_active(q)) {
dprintk(1, "file io in progress\n");
return -EBUSY;
}
return vb2_core_streamoff(q, type);
}
EXPORT_SYMBOL_GPL(vb2_streamoff);
/**
* vb2_expbuf() - Export a buffer as a file descriptor
* @q: videobuf2 queue
* @eb: export buffer structure passed from userspace to vidioc_expbuf
* handler in driver
*
* The return values from this function are intended to be directly returned
* from vidioc_expbuf handler in driver.
*/
int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
{
return vb2_core_expbuf(q, &eb->fd, eb->type, eb->index,
eb->plane, eb->flags);
}
EXPORT_SYMBOL_GPL(vb2_expbuf);
/**
* 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)
{
/*
* Sanity check
*/
if (WARN_ON(!q) ||
WARN_ON(q->timestamp_flags &
~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
return -EINVAL;
/* Warn that the driver should choose an appropriate timestamp type */
WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
/* Warn that vb2_memory should match with v4l2_memory */
if (WARN_ON(VB2_MEMORY_MMAP != (int)V4L2_MEMORY_MMAP)
|| WARN_ON(VB2_MEMORY_USERPTR != (int)V4L2_MEMORY_USERPTR)
|| WARN_ON(VB2_MEMORY_DMABUF != (int)V4L2_MEMORY_DMABUF))
return -EINVAL;
if (q->buf_struct_size == 0)
q->buf_struct_size = sizeof(struct vb2_v4l2_buffer);
q->buf_ops = &v4l2_buf_ops;
q->is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
q->is_output = V4L2_TYPE_IS_OUTPUT(q->type);
return vb2_core_queue_init(q);
}
EXPORT_SYMBOL_GPL(vb2_queue_init);
static int __vb2_init_fileio(struct vb2_queue *q, int read);
static int __vb2_cleanup_fileio(struct vb2_queue *q);
/**
* 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_core_queue_release(q);
}
EXPORT_SYMBOL_GPL(vb2_queue_release);
/**
* 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.
*
* If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
* pending events.
*
* 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)
{
struct video_device *vfd = video_devdata(file);
unsigned long req_events = poll_requested_events(wait);
struct vb2_buffer *vb = NULL;
unsigned int res = 0;
unsigned long flags;
if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
struct v4l2_fh *fh = file->private_data;
if (v4l2_event_pending(fh))
res = POLLPRI;
else if (req_events & POLLPRI)
poll_wait(file, &fh->wait, wait);
}
if (!q->is_output && !(req_events & (POLLIN | POLLRDNORM)))
return res;
if (q->is_output && !(req_events & (POLLOUT | POLLWRNORM)))
return res;
/*
* Start file I/O emulator only if streaming API has not been used yet.
*/
if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
if (!q->is_output && (q->io_modes & VB2_READ) &&
(req_events & (POLLIN | POLLRDNORM))) {
if (__vb2_init_fileio(q, 1))
return res | POLLERR;
}
if (q->is_output && (q->io_modes & VB2_WRITE) &&
(req_events & (POLLOUT | POLLWRNORM))) {
if (__vb2_init_fileio(q, 0))
return res | POLLERR;
/*
* Write to OUTPUT queue can be done immediately.
*/
return res | POLLOUT | POLLWRNORM;
}
}
/*
* There is nothing to wait for if the queue isn't streaming, or if the
* error flag is set.
*/
if (!vb2_is_streaming(q) || q->error)
return res | POLLERR;
/*
* For compatibility with vb1: if QBUF hasn't been called yet, then
* return POLLERR as well. This only affects capture queues, output
* queues will always initialize waiting_for_buffers to false.
*/
if (q->waiting_for_buffers)
return res | POLLERR;
/*
* For output streams you can write as long as there are fewer buffers
* queued than there are buffers available.
*/
if (q->is_output && q->queued_count < q->num_buffers)
return res | POLLOUT | POLLWRNORM;
if (list_empty(&q->done_list)) {
/*
* If the last buffer was dequeued from a capture queue,
* return immediately. DQBUF will return -EPIPE.
*/
if (q->last_buffer_dequeued)
return res | POLLIN | POLLRDNORM;
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 (q->is_output) ?
res | POLLOUT | POLLWRNORM :
res | POLLIN | POLLRDNORM;
}
return res;
}
EXPORT_SYMBOL_GPL(vb2_poll);
/**
* 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
*
* @cur_index: the index of the buffer currently being read from or
* written to. If equal to q->num_buffers then a new buffer
* must be dequeued.
* @initial_index: in the read() case all buffers are queued up immediately
* in __vb2_init_fileio() and __vb2_perform_fileio() just cycles
* buffers. However, in the write() case no buffers are initially
* queued, instead whenever a buffer is full it is queued up by
* __vb2_perform_fileio(). Only once all available buffers have
* been queued up will __vb2_perform_fileio() start to dequeue
* buffers. This means that initially __vb2_perform_fileio()
* needs to know what buffer index to use when it is queuing up
* the buffers for the first time. That initial index is stored
* in this field. Once it is equal to q->num_buffers all
* available buffers have been queued and __vb2_perform_fileio()
* should start the normal dequeue/queue cycle.
*
* 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_plane p;
struct v4l2_buffer b;
struct vb2_fileio_buf bufs[VB2_MAX_FRAME];
unsigned int cur_index;
unsigned int initial_index;
unsigned int q_count;
unsigned int dq_count;
unsigned read_once:1;
unsigned write_immediately:1;
};
/**
* __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 (WARN_ON((read && !(q->io_modes & VB2_READ)) ||
(!read && !(q->io_modes & VB2_WRITE))))
return -EINVAL;
/*
* 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, read_once %d, write_immediately %d\n",
(read) ? "read" : "write", count, q->fileio_read_once,
q->fileio_write_immediately);
fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
if (fileio == NULL)
return -ENOMEM;
fileio->read_once = q->fileio_read_once;
fileio->write_immediately = q->fileio_write_immediately;
/*
* Request buffers and use MMAP type to force driver
* to allocate buffers by itself.
*/
fileio->req.count = count;
fileio->req.memory = VB2_MEMORY_MMAP;
fileio->req.type = q->type;
q->fileio = fileio;
ret = vb2_core_reqbufs(q, fileio->req.memory, &fileio->req.count);
if (ret)
goto err_kfree;
/*
* Check if plane_count is correct
* (multiplane buffers are not supported).
*/
if (q->bufs[0]->num_planes != 1) {
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) {
ret = -EINVAL;
goto err_reqbufs;
}
fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
}
/*
* Read mode requires pre queuing of all buffers.
*/
if (read) {
bool is_multiplanar = q->is_multiplanar;
/*
* 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;
if (is_multiplanar) {
memset(&fileio->p, 0, sizeof(fileio->p));
b->m.planes = &fileio->p;
b->length = 1;
}
b->memory = q->memory;
b->index = i;
ret = vb2_internal_qbuf(q, b);
if (ret)
goto err_reqbufs;
fileio->bufs[i].queued = 1;
}
/*
* All buffers have been queued, so mark that by setting
* initial_index to q->num_buffers
*/
fileio->initial_index = q->num_buffers;
fileio->cur_index = q->num_buffers;
}
/*
* Start streaming.
*/
ret = vb2_core_streamon(q, q->type);
if (ret)
goto err_reqbufs;
return ret;
err_reqbufs:
fileio->req.count = 0;
vb2_core_reqbufs(q, fileio->req.memory, &fileio->req.count);
err_kfree:
q->fileio = NULL;
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) {
vb2_core_streamoff(q, q->type);
q->fileio = NULL;
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;
bool is_multiplanar = q->is_multiplanar;
/*
* When using write() to write data to an output video node the vb2 core
* should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
* else is able to provide this information with the write() operation.
*/
bool set_timestamp = !read &&
(q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
V4L2_BUF_FLAG_TIMESTAMP_COPY;
int ret, index;
dprintk(3, "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 (!vb2_fileio_is_active(q)) {
ret = __vb2_init_fileio(q, read);
dprintk(3, "vb2_init_fileio result: %d\n", ret);
if (ret)
return ret;
}
fileio = q->fileio;
/*
* Check if we need to dequeue the buffer.
*/
index = fileio->cur_index;
if (index >= q->num_buffers) {
/*
* Call vb2_dqbuf to get buffer back.
*/
memset(&fileio->b, 0, sizeof(fileio->b));
fileio->b.type = q->type;
fileio->b.memory = q->memory;
if (is_multiplanar) {
memset(&fileio->p, 0, sizeof(fileio->p));
fileio->b.m.planes = &fileio->p;
fileio->b.length = 1;
}
ret = vb2_internal_dqbuf(q, &fileio->b, nonblock);
dprintk(5, "vb2_dqbuf result: %d\n", ret);
if (ret)
return ret;
fileio->dq_count += 1;
fileio->cur_index = index = fileio->b.index;
buf = &fileio->bufs[index];
/*
* Get number of bytes filled by the driver
*/
buf->pos = 0;
buf->queued = 0;
buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0)
: vb2_plane_size(q->bufs[index], 0);
/* Compensate for data_offset on read in the multiplanar case. */
if (is_multiplanar && read &&
fileio->b.m.planes[0].data_offset < buf->size) {
buf->pos = fileio->b.m.planes[0].data_offset;
buf->size -= buf->pos;
}
} else {
buf = &fileio->bufs[index];
}
/*
* 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, "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, "error copying data\n");
return -EFAULT;
}
/*
* Update counters.
*/
buf->pos += count;
*ppos += count;
/*
* Queue next buffer if required.
*/
if (buf->pos == buf->size || (!read && fileio->write_immediately)) {
/*
* Check if this is the last buffer to read.
*/
if (read && fileio->read_once && fileio->dq_count == 1) {
dprintk(3, "read limit reached\n");
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;
if (is_multiplanar) {
memset(&fileio->p, 0, sizeof(fileio->p));
fileio->p.bytesused = buf->pos;
fileio->b.m.planes = &fileio->p;
fileio->b.length = 1;
}
if (set_timestamp)
v4l2_get_timestamp(&fileio->b.timestamp);
ret = vb2_internal_qbuf(q, &fileio->b);
dprintk(5, "vb2_dbuf result: %d\n", ret);
if (ret)
return ret;
/*
* Buffer has been queued, update the status
*/
buf->pos = 0;
buf->queued = 1;
buf->size = vb2_plane_size(q->bufs[index], 0);
fileio->q_count += 1;
/*
* If we are queuing up buffers for the first time, then
* increase initial_index by one.
*/
if (fileio->initial_index < q->num_buffers)
fileio->initial_index++;
/*
* The next buffer to use is either a buffer that's going to be
* queued for the first time (initial_index < q->num_buffers)
* or it is equal to q->num_buffers, meaning that the next
* time we need to dequeue a buffer since we've now queued up
* all the 'first time' buffers.
*/
fileio->cur_index = fileio->initial_index;
}
/*
* Return proper number of bytes processed.
*/
if (ret == 0)
ret = count;
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, const char __user *data, size_t count,
loff_t *ppos, int nonblocking)
{
return __vb2_perform_fileio(q, (char __user *) data, count,
ppos, nonblocking, 0);
}
EXPORT_SYMBOL_GPL(vb2_write);
struct vb2_threadio_data {
struct task_struct *thread;
vb2_thread_fnc fnc;
void *priv;
bool stop;
};
static int vb2_thread(void *data)
{
struct vb2_queue *q = data;
struct vb2_threadio_data *threadio = q->threadio;
struct vb2_fileio_data *fileio = q->fileio;
bool set_timestamp = false;
int prequeue = 0;
int index = 0;
int ret = 0;
if (q->is_output) {
prequeue = q->num_buffers;
set_timestamp =
(q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
V4L2_BUF_FLAG_TIMESTAMP_COPY;
}
set_freezable();
for (;;) {
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;
if (prequeue) {
fileio->b.index = index++;
prequeue--;
} else {
call_void_qop(q, wait_finish, q);
if (!threadio->stop)
ret = vb2_internal_dqbuf(q, &fileio->b, 0);
call_void_qop(q, wait_prepare, q);
dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
}
if (ret || threadio->stop)
break;
try_to_freeze();
vb = q->bufs[fileio->b.index];
if (!(fileio->b.flags & V4L2_BUF_FLAG_ERROR))
if (threadio->fnc(vb, threadio->priv))
break;
call_void_qop(q, wait_finish, q);
if (set_timestamp)
v4l2_get_timestamp(&fileio->b.timestamp);
if (!threadio->stop)
ret = vb2_internal_qbuf(q, &fileio->b);
call_void_qop(q, wait_prepare, q);
if (ret || threadio->stop)
break;
}
/* Hmm, linux becomes *very* unhappy without this ... */
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
schedule();
}
return 0;
}
/*
* 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 mailinglist first.
*/
int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
const char *thread_name)
{
struct vb2_threadio_data *threadio;
int ret = 0;
if (q->threadio)
return -EBUSY;
if (vb2_is_busy(q))
return -EBUSY;
if (WARN_ON(q->fileio))
return -EBUSY;
threadio = kzalloc(sizeof(*threadio), GFP_KERNEL);
if (threadio == NULL)
return -ENOMEM;
threadio->fnc = fnc;
threadio->priv = priv;
ret = __vb2_init_fileio(q, !q->is_output);
dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
if (ret)
goto nomem;
q->threadio = threadio;
threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name);
if (IS_ERR(threadio->thread)) {
ret = PTR_ERR(threadio->thread);
threadio->thread = NULL;
goto nothread;
}
return 0;
nothread:
__vb2_cleanup_fileio(q);
nomem:
kfree(threadio);
return ret;
}
EXPORT_SYMBOL_GPL(vb2_thread_start);
int vb2_thread_stop(struct vb2_queue *q)
{
struct vb2_threadio_data *threadio = q->threadio;
int err;
if (threadio == NULL)
return 0;
threadio->stop = true;
/* Wake up all pending sleeps in the thread */
vb2_queue_error(q);
err = kthread_stop(threadio->thread);
__vb2_cleanup_fileio(q);
threadio->thread = NULL;
kfree(threadio);
q->threadio = NULL;
return err;
}
EXPORT_SYMBOL_GPL(vb2_thread_stop);
/*
* The following functions are not part of the vb2 core API, but are helper
* functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
* and struct vb2_ops.
* They contain boilerplate code that most if not all drivers have to do
* and so they simplify the driver code.
*/
/* The queue is busy if there is a owner and you are not that owner. */
static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
{
return vdev->queue->owner && vdev->queue->owner != file->private_data;
}
/* vb2 ioctl helpers */
int vb2_ioctl_reqbufs(struct file *file, void *priv,
struct v4l2_requestbuffers *p)
{
struct video_device *vdev = video_devdata(file);
int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type);
if (res)
return res;
if (vb2_queue_is_busy(vdev, file))
return -EBUSY;
res = vb2_core_reqbufs(vdev->queue, p->memory, &p->count);
/* If count == 0, then the owner has released all buffers and he
is no longer owner of the queue. Otherwise we have a new owner. */
if (res == 0)
vdev->queue->owner = p->count ? file->private_data : NULL;
return res;
}
EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
int vb2_ioctl_create_bufs(struct file *file, void *priv,
struct v4l2_create_buffers *p)
{
struct video_device *vdev = video_devdata(file);
int res = vb2_verify_memory_type(vdev->queue, p->memory,
p->format.type);
p->index = vdev->queue->num_buffers;
/*
* If count == 0, then just check if memory and type are valid.
* Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
*/
if (p->count == 0)
return res != -EBUSY ? res : 0;
if (res)
return res;
if (vb2_queue_is_busy(vdev, file))
return -EBUSY;
res = vb2_core_create_bufs(vdev->queue, p->memory, &p->count,
&p->format);
if (res == 0)
vdev->queue->owner = file->private_data;
return res;
}
EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
int vb2_ioctl_prepare_buf(struct file *file, void *priv,
struct v4l2_buffer *p)
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
return -EBUSY;
return vb2_prepare_buf(vdev->queue, p);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
struct video_device *vdev = video_devdata(file);
/* No need to call vb2_queue_is_busy(), anyone can query buffers. */
return vb2_querybuf(vdev->queue, p);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
return -EBUSY;
return vb2_qbuf(vdev->queue, p);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
return -EBUSY;
return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
return -EBUSY;
return vb2_streamon(vdev->queue, i);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
return -EBUSY;
return vb2_streamoff(vdev->queue, i);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
return -EBUSY;
return vb2_expbuf(vdev->queue, p);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
/* v4l2_file_operations helpers */
int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
{
struct video_device *vdev = video_devdata(file);
return vb2_mmap(vdev->queue, vma);
}
EXPORT_SYMBOL_GPL(vb2_fop_mmap);
int _vb2_fop_release(struct file *file, struct mutex *lock)
{
struct video_device *vdev = video_devdata(file);
if (lock)
mutex_lock(lock);
if (file->private_data == vdev->queue->owner) {
vb2_queue_release(vdev->queue);
vdev->queue->owner = NULL;
}
if (lock)
mutex_unlock(lock);
return v4l2_fh_release(file);
}
EXPORT_SYMBOL_GPL(_vb2_fop_release);
int vb2_fop_release(struct file *file)
{
struct video_device *vdev = video_devdata(file);
struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
return _vb2_fop_release(file, lock);
}
EXPORT_SYMBOL_GPL(vb2_fop_release);
ssize_t vb2_fop_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct video_device *vdev = video_devdata(file);
struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
int err = -EBUSY;
if (!(vdev->queue->io_modes & VB2_WRITE))
return -EINVAL;
if (lock && mutex_lock_interruptible(lock))
return -ERESTARTSYS;
if (vb2_queue_is_busy(vdev, file))
goto exit;
err = vb2_write(vdev->queue, buf, count, ppos,
file->f_flags & O_NONBLOCK);
if (vdev->queue->fileio)
vdev->queue->owner = file->private_data;
exit:
if (lock)
mutex_unlock(lock);
return err;
}
EXPORT_SYMBOL_GPL(vb2_fop_write);
ssize_t vb2_fop_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct video_device *vdev = video_devdata(file);
struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
int err = -EBUSY;
if (!(vdev->queue->io_modes & VB2_READ))
return -EINVAL;
if (lock && mutex_lock_interruptible(lock))
return -ERESTARTSYS;
if (vb2_queue_is_busy(vdev, file))
goto exit;
err = vb2_read(vdev->queue, buf, count, ppos,
file->f_flags & O_NONBLOCK);
if (vdev->queue->fileio)
vdev->queue->owner = file->private_data;
exit:
if (lock)
mutex_unlock(lock);
return err;
}
EXPORT_SYMBOL_GPL(vb2_fop_read);
unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
{
struct video_device *vdev = video_devdata(file);
struct vb2_queue *q = vdev->queue;
struct mutex *lock = q->lock ? q->lock : vdev->lock;
unsigned res;
void *fileio;
/*
* If this helper doesn't know how to lock, then you shouldn't be using
* it but you should write your own.
*/
WARN_ON(!lock);
if (lock && mutex_lock_interruptible(lock))
return POLLERR;
fileio = q->fileio;
res = vb2_poll(vdev->queue, file, wait);
/* If fileio was started, then we have a new queue owner. */
if (!fileio && q->fileio)
q->owner = file->private_data;
if (lock)
mutex_unlock(lock);
return res;
}
EXPORT_SYMBOL_GPL(vb2_fop_poll);
#ifndef CONFIG_MMU
unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct video_device *vdev = video_devdata(file);
return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
}
EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
#endif
/* vb2_ops helpers. Only use if vq->lock is non-NULL. */
void vb2_ops_wait_prepare(struct vb2_queue *vq)
{
mutex_unlock(vq->lock);
}
EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
void vb2_ops_wait_finish(struct vb2_queue *vq)
{
mutex_lock(vq->lock);
}
EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
MODULE_LICENSE("GPL");