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Diffstat (limited to 'drivers/media/v4l2-core/videobuf2-core.c')
-rw-r--r--drivers/media/v4l2-core/videobuf2-core.c2380
1 files changed, 2380 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
new file mode 100644
index 000000000000..4da3df61901f
--- /dev/null
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -0,0 +1,2380 @@
+/*
+ * videobuf2-core.c - V4L2 driver helper framework
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <pawel@osciak.com>
+ * Marek Szyprowski <m.szyprowski@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#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 <media/v4l2-dev.h>
+#include <media/v4l2-fh.h>
+#include <media/v4l2-event.h>
+#include <media/videobuf2-core.h>
+
+static int debug;
+module_param(debug, int, 0644);
+
+#define dprintk(level, fmt, arg...) \
+ do { \
+ if (debug >= level) \
+ printk(KERN_DEBUG "vb2: " fmt, ## arg); \
+ } while (0)
+
+#define call_memop(q, op, args...) \
+ (((q)->mem_ops->op) ? \
+ ((q)->mem_ops->op(args)) : 0)
+
+#define call_qop(q, op, args...) \
+ (((q)->ops->op) ? ((q)->ops->op(args)) : 0)
+
+#define V4L2_BUFFER_STATE_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
+ V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
+ V4L2_BUF_FLAG_PREPARED)
+
+/**
+ * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
+ */
+static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+ void *mem_priv;
+ int plane;
+
+ /* Allocate memory for all planes in this buffer */
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ mem_priv = call_memop(q, alloc, q->alloc_ctx[plane],
+ q->plane_sizes[plane]);
+ if (IS_ERR_OR_NULL(mem_priv))
+ goto free;
+
+ /* Associate allocator private data with this plane */
+ vb->planes[plane].mem_priv = mem_priv;
+ vb->v4l2_planes[plane].length = q->plane_sizes[plane];
+ }
+
+ return 0;
+free:
+ /* Free already allocated memory if one of the allocations failed */
+ for (; plane > 0; --plane) {
+ call_memop(q, put, vb->planes[plane - 1].mem_priv);
+ vb->planes[plane - 1].mem_priv = NULL;
+ }
+
+ return -ENOMEM;
+}
+
+/**
+ * __vb2_buf_mem_free() - free memory of the given buffer
+ */
+static void __vb2_buf_mem_free(struct vb2_buffer *vb)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+ unsigned int plane;
+
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ call_memop(q, put, vb->planes[plane].mem_priv);
+ vb->planes[plane].mem_priv = NULL;
+ dprintk(3, "Freed plane %d of buffer %d\n", plane,
+ vb->v4l2_buf.index);
+ }
+}
+
+/**
+ * __vb2_buf_userptr_put() - release userspace memory associated with
+ * a USERPTR buffer
+ */
+static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+ unsigned int plane;
+
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ if (vb->planes[plane].mem_priv)
+ call_memop(q, put_userptr, vb->planes[plane].mem_priv);
+ vb->planes[plane].mem_priv = NULL;
+ }
+}
+
+/**
+ * __setup_offsets() - setup unique offsets ("cookies") for every plane in
+ * every buffer on the queue
+ */
+static void __setup_offsets(struct vb2_queue *q, unsigned int n)
+{
+ unsigned int buffer, plane;
+ struct vb2_buffer *vb;
+ unsigned long off;
+
+ if (q->num_buffers) {
+ struct v4l2_plane *p;
+ vb = q->bufs[q->num_buffers - 1];
+ p = &vb->v4l2_planes[vb->num_planes - 1];
+ off = PAGE_ALIGN(p->m.mem_offset + p->length);
+ } else {
+ off = 0;
+ }
+
+ for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
+ vb = q->bufs[buffer];
+ if (!vb)
+ continue;
+
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ vb->v4l2_planes[plane].length = q->plane_sizes[plane];
+ vb->v4l2_planes[plane].m.mem_offset = off;
+
+ dprintk(3, "Buffer %d, plane %d offset 0x%08lx\n",
+ buffer, plane, off);
+
+ off += vb->v4l2_planes[plane].length;
+ off = PAGE_ALIGN(off);
+ }
+ }
+}
+
+/**
+ * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
+ * video buffer memory for all buffers/planes on the queue and initializes the
+ * queue
+ *
+ * Returns the number of buffers successfully allocated.
+ */
+static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
+ unsigned int num_buffers, unsigned int num_planes)
+{
+ unsigned int buffer;
+ struct vb2_buffer *vb;
+ int ret;
+
+ for (buffer = 0; buffer < num_buffers; ++buffer) {
+ /* Allocate videobuf buffer structures */
+ vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
+ if (!vb) {
+ dprintk(1, "Memory alloc for buffer struct failed\n");
+ break;
+ }
+
+ /* Length stores number of planes for multiplanar buffers */
+ if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
+ vb->v4l2_buf.length = num_planes;
+
+ vb->state = VB2_BUF_STATE_DEQUEUED;
+ vb->vb2_queue = q;
+ vb->num_planes = num_planes;
+ vb->v4l2_buf.index = q->num_buffers + buffer;
+ vb->v4l2_buf.type = q->type;
+ vb->v4l2_buf.memory = memory;
+
+ /* Allocate video buffer memory for the MMAP type */
+ if (memory == V4L2_MEMORY_MMAP) {
+ ret = __vb2_buf_mem_alloc(vb);
+ if (ret) {
+ dprintk(1, "Failed allocating memory for "
+ "buffer %d\n", buffer);
+ kfree(vb);
+ break;
+ }
+ /*
+ * Call the driver-provided buffer initialization
+ * callback, if given. An error in initialization
+ * results in queue setup failure.
+ */
+ ret = call_qop(q, buf_init, vb);
+ if (ret) {
+ dprintk(1, "Buffer %d %p initialization"
+ " failed\n", buffer, vb);
+ __vb2_buf_mem_free(vb);
+ kfree(vb);
+ break;
+ }
+ }
+
+ q->bufs[q->num_buffers + buffer] = vb;
+ }
+
+ __setup_offsets(q, buffer);
+
+ dprintk(1, "Allocated %d buffers, %d plane(s) each\n",
+ buffer, num_planes);
+
+ return buffer;
+}
+
+/**
+ * __vb2_free_mem() - release all video buffer memory for a given queue
+ */
+static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
+{
+ unsigned int buffer;
+ struct vb2_buffer *vb;
+
+ for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+ ++buffer) {
+ vb = q->bufs[buffer];
+ if (!vb)
+ continue;
+
+ /* Free MMAP buffers or release USERPTR buffers */
+ if (q->memory == V4L2_MEMORY_MMAP)
+ __vb2_buf_mem_free(vb);
+ else
+ __vb2_buf_userptr_put(vb);
+ }
+}
+
+/**
+ * __vb2_queue_free() - free buffers at the end of the queue - video memory and
+ * related information, if no buffers are left return the queue to an
+ * uninitialized state. Might be called even if the queue has already been freed.
+ */
+static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
+{
+ unsigned int buffer;
+
+ /* Call driver-provided cleanup function for each buffer, if provided */
+ if (q->ops->buf_cleanup) {
+ for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+ ++buffer) {
+ if (NULL == q->bufs[buffer])
+ continue;
+ q->ops->buf_cleanup(q->bufs[buffer]);
+ }
+ }
+
+ /* Release video buffer memory */
+ __vb2_free_mem(q, buffers);
+
+ /* Free videobuf buffers */
+ for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
+ ++buffer) {
+ kfree(q->bufs[buffer]);
+ q->bufs[buffer] = NULL;
+ }
+
+ q->num_buffers -= buffers;
+ if (!q->num_buffers)
+ q->memory = 0;
+ INIT_LIST_HEAD(&q->queued_list);
+}
+
+/**
+ * __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)
+{
+ /* 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 > VIDEO_MAX_PLANES) {
+ dprintk(1, "Incorrect planes array length, "
+ "expected %d, got %d\n", vb->num_planes, b->length);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * __buffer_in_use() - return true if the buffer is in use and
+ * the queue cannot be freed (by the means of REQBUFS(0)) call
+ */
+static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
+{
+ unsigned int plane;
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ void *mem_priv = vb->planes[plane].mem_priv;
+ /*
+ * If num_users() has not been provided, call_memop
+ * will return 0, apparently nobody cares about this
+ * case anyway. If num_users() returns more than 1,
+ * we are not the only user of the plane's memory.
+ */
+ if (mem_priv && call_memop(q, num_users, mem_priv) > 1)
+ return true;
+ }
+ return false;
+}
+
+/**
+ * __buffers_in_use() - return true if any buffers on the queue are in use and
+ * the queue cannot be freed (by the means of REQBUFS(0)) call
+ */
+static bool __buffers_in_use(struct vb2_queue *q)
+{
+ unsigned int buffer;
+ for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+ if (__buffer_in_use(q, q->bufs[buffer]))
+ return true;
+ }
+ return false;
+}
+
+/**
+ * __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, struct v4l2_buffer *b)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+ int ret;
+
+ /* Copy back data such as timestamp, flags, etc. */
+ memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
+ b->reserved2 = vb->v4l2_buf.reserved2;
+ b->reserved = vb->v4l2_buf.reserved;
+
+ if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
+ ret = __verify_planes_array(vb, b);
+ if (ret)
+ return ret;
+
+ /*
+ * Fill in plane-related data if userspace provided an array
+ * for it. The memory and size is verified above.
+ */
+ memcpy(b->m.planes, vb->v4l2_planes,
+ b->length * sizeof(struct v4l2_plane));
+ } else {
+ /*
+ * We use length and offset in v4l2_planes array even for
+ * single-planar buffers, but userspace does not.
+ */
+ b->length = vb->v4l2_planes[0].length;
+ b->bytesused = vb->v4l2_planes[0].bytesused;
+ if (q->memory == V4L2_MEMORY_MMAP)
+ b->m.offset = vb->v4l2_planes[0].m.mem_offset;
+ else if (q->memory == V4L2_MEMORY_USERPTR)
+ b->m.userptr = vb->v4l2_planes[0].m.userptr;
+ }
+
+ /*
+ * Clear any buffer state related flags.
+ */
+ b->flags &= ~V4L2_BUFFER_STATE_FLAGS;
+
+ 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_DEQUEUED:
+ /* nothing */
+ break;
+ }
+
+ if (__buffer_in_use(q, vb))
+ b->flags |= V4L2_BUF_FLAG_MAPPED;
+
+ return 0;
+}
+
+/**
+ * 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;
+
+ if (b->type != q->type) {
+ dprintk(1, "querybuf: wrong buffer type\n");
+ return -EINVAL;
+ }
+
+ if (b->index >= q->num_buffers) {
+ dprintk(1, "querybuf: buffer index out of range\n");
+ return -EINVAL;
+ }
+ vb = q->bufs[b->index];
+
+ return __fill_v4l2_buffer(vb, b);
+}
+EXPORT_SYMBOL(vb2_querybuf);
+
+/**
+ * __verify_userptr_ops() - verify that all memory operations required for
+ * USERPTR queue type have been provided
+ */
+static int __verify_userptr_ops(struct vb2_queue *q)
+{
+ if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
+ !q->mem_ops->put_userptr)
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * __verify_mmap_ops() - verify that all memory operations required for
+ * MMAP queue type have been provided
+ */
+static int __verify_mmap_ops(struct vb2_queue *q)
+{
+ if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
+ !q->mem_ops->put || !q->mem_ops->mmap)
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * __verify_memory_type() - Check whether the memory type and buffer type
+ * passed to a buffer operation are compatible with the queue.
+ */
+static int __verify_memory_type(struct vb2_queue *q,
+ enum v4l2_memory memory, enum v4l2_buf_type type)
+{
+ if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR) {
+ dprintk(1, "reqbufs: unsupported memory type\n");
+ return -EINVAL;
+ }
+
+ if (type != q->type) {
+ dprintk(1, "reqbufs: requested type is incorrect\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Make sure all the required memory ops for given memory type
+ * are available.
+ */
+ if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
+ dprintk(1, "reqbufs: MMAP for current setup unsupported\n");
+ return -EINVAL;
+ }
+
+ if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
+ dprintk(1, "reqbufs: USERPTR for current setup unsupported\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Place the busy tests at the end: -EBUSY can be ignored when
+ * create_bufs is called with count == 0, but count == 0 should still
+ * do the memory and type validation.
+ */
+ if (q->fileio) {
+ dprintk(1, "reqbufs: file io in progress\n");
+ return -EBUSY;
+ }
+ return 0;
+}
+
+/**
+ * __reqbufs() - Initiate streaming
+ * @q: videobuf2 queue
+ * @req: struct passed from userspace to vidioc_reqbufs handler in driver
+ *
+ * Should be called from vidioc_reqbufs ioctl handler of a driver.
+ * This function:
+ * 1) verifies streaming parameters passed from the userspace,
+ * 2) sets up the queue,
+ * 3) negotiates number of buffers and planes per buffer with the driver
+ * to be used during streaming,
+ * 4) allocates internal buffer structures (struct vb2_buffer), according to
+ * the agreed parameters,
+ * 5) for MMAP memory type, allocates actual video memory, using the
+ * memory handling/allocation routines provided during queue initialization
+ *
+ * If req->count is 0, all the memory will be freed instead.
+ * If the queue has been allocated previously (by a previous vb2_reqbufs) call
+ * and the queue is not busy, memory will be reallocated.
+ *
+ * The return values from this function are intended to be directly returned
+ * from vidioc_reqbufs handler in driver.
+ */
+static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
+{
+ unsigned int num_buffers, allocated_buffers, num_planes = 0;
+ int ret;
+
+ if (q->streaming) {
+ dprintk(1, "reqbufs: streaming active\n");
+ return -EBUSY;
+ }
+
+ if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
+ /*
+ * We already have buffers allocated, so first check if they
+ * are not in use and can be freed.
+ */
+ if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
+ dprintk(1, "reqbufs: memory in use, cannot free\n");
+ return -EBUSY;
+ }
+
+ __vb2_queue_free(q, q->num_buffers);
+
+ /*
+ * 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(q->plane_sizes, 0, sizeof(q->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, NULL, &num_buffers, &num_planes,
+ q->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);
+ if (ret == 0) {
+ dprintk(1, "Memory allocation failed\n");
+ return -ENOMEM;
+ }
+
+ allocated_buffers = ret;
+
+ /*
+ * Check if driver can handle the allocated number of buffers.
+ */
+ if (allocated_buffers < num_buffers) {
+ num_buffers = allocated_buffers;
+
+ ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
+ &num_planes, q->plane_sizes, q->alloc_ctx);
+
+ if (!ret && allocated_buffers < num_buffers)
+ ret = -ENOMEM;
+
+ /*
+ * Either the driver has accepted a smaller number of buffers,
+ * or .queue_setup() returned an error
+ */
+ }
+
+ q->num_buffers = allocated_buffers;
+
+ if (ret < 0) {
+ __vb2_queue_free(q, allocated_buffers);
+ return ret;
+ }
+
+ /*
+ * Return the number of successfully allocated buffers
+ * to the userspace.
+ */
+ req->count = allocated_buffers;
+
+ return 0;
+}
+
+/**
+ * vb2_reqbufs() - Wrapper for __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 = __verify_memory_type(q, req->memory, req->type);
+
+ return ret ? ret : __reqbufs(q, req);
+}
+EXPORT_SYMBOL_GPL(vb2_reqbufs);
+
+/**
+ * __create_bufs() - Allocate buffers and any required auxiliary structs
+ * @q: videobuf2 queue
+ * @create: creation parameters, passed from userspace to vidioc_create_bufs
+ * handler in driver
+ *
+ * Should be called from vidioc_create_bufs ioctl handler of a driver.
+ * This function:
+ * 1) verifies parameter sanity
+ * 2) calls the .queue_setup() queue operation
+ * 3) performs any necessary memory allocations
+ *
+ * The return values from this function are intended to be directly returned
+ * from vidioc_create_bufs handler in driver.
+ */
+static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
+{
+ unsigned int num_planes = 0, num_buffers, allocated_buffers;
+ int ret;
+
+ if (q->num_buffers == VIDEO_MAX_FRAME) {
+ dprintk(1, "%s(): maximum number of buffers already allocated\n",
+ __func__);
+ return -ENOBUFS;
+ }
+
+ if (!q->num_buffers) {
+ memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
+ memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
+ q->memory = create->memory;
+ }
+
+ num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
+
+ /*
+ * Ask the driver, whether the requested number of buffers, planes per
+ * buffer and their sizes are acceptable
+ */
+ ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
+ &num_planes, q->plane_sizes, q->alloc_ctx);
+ if (ret)
+ return ret;
+
+ /* Finally, allocate buffers and video memory */
+ ret = __vb2_queue_alloc(q, create->memory, num_buffers,
+ num_planes);
+ if (ret == 0) {
+ dprintk(1, "Memory allocation failed\n");
+ return -ENOMEM;
+ }
+
+ allocated_buffers = ret;
+
+ /*
+ * Check if driver can handle the so far allocated number of buffers.
+ */
+ if (ret < num_buffers) {
+ num_buffers = ret;
+
+ /*
+ * q->num_buffers contains the total number of buffers, that the
+ * queue driver has set up
+ */
+ ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
+ &num_planes, q->plane_sizes, q->alloc_ctx);
+
+ if (!ret && allocated_buffers < num_buffers)
+ ret = -ENOMEM;
+
+ /*
+ * Either the driver has accepted a smaller number of buffers,
+ * or .queue_setup() returned an error
+ */
+ }
+
+ q->num_buffers += allocated_buffers;
+
+ if (ret < 0) {
+ __vb2_queue_free(q, allocated_buffers);
+ return -ENOMEM;
+ }
+
+ /*
+ * Return the number of successfully allocated buffers
+ * to the userspace.
+ */
+ create->count = allocated_buffers;
+
+ return 0;
+}
+
+/**
+ * vb2_create_bufs() - Wrapper for __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 = __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 : __create_bufs(q, create);
+}
+EXPORT_SYMBOL_GPL(vb2_create_bufs);
+
+/**
+ * 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 || !vb->planes[plane_no].mem_priv)
+ return NULL;
+
+ return call_memop(q, 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 || !vb->planes[plane_no].mem_priv)
+ return NULL;
+
+ return call_memop(q, 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, const 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.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, const 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 &&
+ 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);
+
+ /* Check if the provided plane buffer is large enough */
+ if (planes[plane].length < q->plane_sizes[plane]) {
+ ret = -EINVAL;
+ goto err;
+ }
+
+ /* Release previously acquired memory if present */
+ if (vb->planes[plane].mem_priv)
+ call_memop(q, put_userptr, vb->planes[plane].mem_priv);
+
+ vb->planes[plane].mem_priv = NULL;
+ vb->v4l2_planes[plane].m.userptr = 0;
+ vb->v4l2_planes[plane].length = 0;
+
+ /* Acquire each plane's memory */
+ mem_priv = call_memop(q, get_userptr, q->alloc_ctx[plane],
+ planes[plane].m.userptr,
+ planes[plane].length, write);
+ if (IS_ERR_OR_NULL(mem_priv)) {
+ dprintk(1, "qbuf: failed acquiring userspace "
+ "memory for plane %d\n", plane);
+ ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
+ 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 < vb->num_planes; ++plane) {
+ if (vb->planes[plane].mem_priv)
+ call_memop(q, put_userptr, vb->planes[plane].mem_priv);
+ vb->planes[plane].mem_priv = NULL;
+ vb->v4l2_planes[plane].m.userptr = 0;
+ vb->v4l2_planes[plane].length = 0;
+ }
+
+ return ret;
+}
+
+/**
+ * __qbuf_mmap() - handle qbuf of an MMAP buffer
+ */
+static int __qbuf_mmap(struct vb2_buffer *vb, const 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);
+}
+
+static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+ int ret;
+
+ switch (q->memory) {
+ case V4L2_MEMORY_MMAP:
+ ret = __qbuf_mmap(vb, b);
+ break;
+ case V4L2_MEMORY_USERPTR:
+ ret = __qbuf_userptr(vb, b);
+ break;
+ default:
+ WARN(1, "Invalid queue type\n");
+ ret = -EINVAL;
+ }
+
+ if (!ret)
+ ret = call_qop(q, buf_prepare, vb);
+ if (ret)
+ dprintk(1, "qbuf: buffer preparation failed: %d\n", ret);
+ else
+ vb->state = VB2_BUF_STATE_PREPARED;
+
+ return ret;
+}
+
+/**
+ * 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)
+{
+ struct vb2_buffer *vb;
+ int ret;
+
+ if (q->fileio) {
+ dprintk(1, "%s(): file io in progress\n", __func__);
+ return -EBUSY;
+ }
+
+ if (b->type != q->type) {
+ dprintk(1, "%s(): invalid buffer type\n", __func__);
+ return -EINVAL;
+ }
+
+ if (b->index >= q->num_buffers) {
+ dprintk(1, "%s(): buffer index out of range\n", __func__);
+ return -EINVAL;
+ }
+
+ vb = q->bufs[b->index];
+ if (NULL == vb) {
+ /* Should never happen */
+ dprintk(1, "%s(): buffer is NULL\n", __func__);
+ return -EINVAL;
+ }
+
+ if (b->memory != q->memory) {
+ dprintk(1, "%s(): invalid memory type\n", __func__);
+ return -EINVAL;
+ }
+
+ if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+ dprintk(1, "%s(): invalid buffer state %d\n", __func__, vb->state);
+ return -EINVAL;
+ }
+
+ ret = __buf_prepare(vb, b);
+ if (ret < 0)
+ return ret;
+
+ __fill_v4l2_buffer(vb, b);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_prepare_buf);
+
+/**
+ * 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)
+{
+ struct rw_semaphore *mmap_sem = NULL;
+ struct vb2_buffer *vb;
+ int ret = 0;
+
+ /*
+ * In case of user pointer buffers vb2 allocator needs to get direct
+ * access to userspace pages. This requires getting read access on
+ * mmap semaphore in the current process structure. The same
+ * semaphore is taken before calling mmap operation, while both mmap
+ * and qbuf are called by the driver or v4l2 core with driver's lock
+ * held. To avoid a AB-BA deadlock (mmap_sem then driver's lock in
+ * mmap and driver's lock then mmap_sem in qbuf) the videobuf2 core
+ * release driver's lock, takes mmap_sem and then takes again driver's
+ * lock.
+ *
+ * To avoid race with other vb2 calls, which might be called after
+ * releasing driver's lock, this operation is performed at the
+ * beggining of qbuf processing. This way the queue status is
+ * consistent after getting driver's lock back.
+ */
+ if (q->memory == V4L2_MEMORY_USERPTR) {
+ mmap_sem = &current->mm->mmap_sem;
+ call_qop(q, wait_prepare, q);
+ down_read(mmap_sem);
+ call_qop(q, wait_finish, q);
+ }
+
+ if (q->fileio) {
+ dprintk(1, "qbuf: file io in progress\n");
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ if (b->type != q->type) {
+ dprintk(1, "qbuf: invalid buffer type\n");
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ if (b->index >= q->num_buffers) {
+ dprintk(1, "qbuf: buffer index out of range\n");
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ vb = q->bufs[b->index];
+ if (NULL == vb) {
+ /* Should never happen */
+ dprintk(1, "qbuf: buffer is NULL\n");
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ if (b->memory != q->memory) {
+ dprintk(1, "qbuf: invalid memory type\n");
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ switch (vb->state) {
+ case VB2_BUF_STATE_DEQUEUED:
+ ret = __buf_prepare(vb, b);
+ if (ret)
+ goto unlock;
+ case VB2_BUF_STATE_PREPARED:
+ break;
+ default:
+ dprintk(1, "qbuf: buffer already in use\n");
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ /*
+ * 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);
+
+ /* Fill buffer information for the userspace */
+ __fill_v4l2_buffer(vb, b);
+
+ dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
+unlock:
+ if (mmap_sem)
+ up_read(mmap_sem);
+ return ret;
+}
+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_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);
+ atomic_set(&q->queued_count, 0);
+ 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_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)
+{
+ 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;
+ }
+
+ /*
+ * 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);
+
+ /*
+ * Let driver notice that streaming state has been enabled.
+ */
+ ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));
+ if (ret) {
+ dprintk(1, "streamon: driver refused to start streaming\n");
+ __vb2_queue_cancel(q);
+ return ret;
+ }
+
+ q->streaming = 1;
+
+ dprintk(3, "Streamon successful\n");
+ return 0;
+}
+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 (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_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];
+
+ ret = call_memop(q, mmap, vb->planes[plane].mem_priv, vma);
+ if (ret)
+ return ret;
+
+ dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_mmap);
+
+#ifndef CONFIG_MMU
+unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
+ unsigned long addr,
+ unsigned long len,
+ unsigned long pgoff,
+ unsigned long flags)
+{
+ unsigned long off = pgoff << PAGE_SHIFT;
+ 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;
+ }
+
+ /*
+ * 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];
+
+ return (unsigned long)vb2_plane_vaddr(vb, plane);
+}
+EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
+#endif
+
+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.
+ *
+ * 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);
+ }
+
+ /*
+ * 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) &&
+ (req_events & (POLLIN | POLLRDNORM))) {
+ if (__vb2_init_fileio(q, 1))
+ return res | POLLERR;
+ }
+ if (V4L2_TYPE_IS_OUTPUT(q->type) && (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 no buffers have already been queued.
+ */
+ if (list_empty(&q->queued_list))
+ return res | 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)) ?
+ res | POLLOUT | POLLWRNORM :
+ res | POLLIN | POLLRDNORM;
+ }
+ return res;
+}
+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, q->num_buffers);
+}
+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) {
+ 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:
+ fileio->req.count = 0;
+ 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);
+
+
+/*
+ * 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 = __verify_memory_type(vdev->queue, p->memory, p->type);
+
+ if (res)
+ return res;
+ if (vb2_queue_is_busy(vdev, file))
+ return -EBUSY;
+ res = __reqbufs(vdev->queue, p);
+ /* 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 = __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 __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 = __create_bufs(vdev->queue, p);
+ 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);
+
+/* 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 video_device *vdev = video_devdata(file);
+
+ if (file->private_data == vdev->queue->owner) {
+ vb2_queue_release(vdev->queue);
+ vdev->queue->owner = NULL;
+ }
+ return v4l2_fh_release(file);
+}
+EXPORT_SYMBOL_GPL(vb2_fop_release);
+
+ssize_t vb2_fop_write(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 (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 (err >= 0)
+ 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 (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 (err >= 0)
+ 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 long req_events = poll_requested_events(wait);
+ unsigned res;
+ void *fileio;
+ bool must_lock = false;
+
+ /* Try to be smart: only lock if polling might start fileio,
+ otherwise locking will only introduce unwanted delays. */
+ if (q->num_buffers == 0 && q->fileio == NULL) {
+ if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
+ (req_events & (POLLIN | POLLRDNORM)))
+ must_lock = true;
+ else if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
+ (req_events & (POLLOUT | POLLWRNORM)))
+ must_lock = true;
+ }
+
+ /* If locking is needed, but this helper doesn't know how, then you
+ shouldn't be using this helper but you should write your own. */
+ WARN_ON(must_lock && !lock);
+
+ if (must_lock && 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 (must_lock && !fileio && q->fileio)
+ q->owner = file->private_data;
+ if (must_lock && 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");

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