--- /dev/null
+/*
+ * 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 call write() as long as there are fewer
+ * buffers queued than there are buffers available.
+ */
+ if (q->is_output && q->fileio && 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");
Code Review / kvmfornfv.git / blobdiff