* (at your option) any later version.
*/
+#include <linux/atomic.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/list.h>
#include <linux/videodev2.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
-#include <linux/atomic.h>
+
+#include <media/videobuf2-vmalloc.h>
#include "uvc.h"
* Video queues is initialized by uvc_queue_init(). The function performs
* basic initialization of the uvc_video_queue struct and never fails.
*
- * Video buffer allocation and freeing are performed by uvc_alloc_buffers and
- * uvc_free_buffers respectively. The former acquires the video queue lock,
- * while the later must be called with the lock held (so that allocation can
- * free previously allocated buffers). Trying to free buffers that are mapped
- * to user space will return -EBUSY.
- *
- * Video buffers are managed using two queues. However, unlike most USB video
- * drivers that use an in queue and an out queue, we use a main queue to hold
- * all queued buffers (both 'empty' and 'done' buffers), and an irq queue to
- * hold empty buffers. This design (copied from video-buf) minimizes locking
- * in interrupt, as only one queue is shared between interrupt and user
- * contexts.
- *
- * Use cases
- * ---------
- *
- * Unless stated otherwise, all operations that modify the irq buffers queue
- * are protected by the irq spinlock.
- *
- * 1. The user queues the buffers, starts streaming and dequeues a buffer.
- *
- * The buffers are added to the main and irq queues. Both operations are
- * protected by the queue lock, and the later is protected by the irq
- * spinlock as well.
- *
- * The completion handler fetches a buffer from the irq queue and fills it
- * with video data. If no buffer is available (irq queue empty), the handler
- * returns immediately.
- *
- * When the buffer is full, the completion handler removes it from the irq
- * queue, marks it as ready (UVC_BUF_STATE_DONE) and wakes its wait queue.
- * At that point, any process waiting on the buffer will be woken up. If a
- * process tries to dequeue a buffer after it has been marked ready, the
- * dequeing will succeed immediately.
- *
- * 2. Buffers are queued, user is waiting on a buffer and the device gets
- * disconnected.
- *
- * When the device is disconnected, the kernel calls the completion handler
- * with an appropriate status code. The handler marks all buffers in the
- * irq queue as being erroneous (UVC_BUF_STATE_ERROR) and wakes them up so
- * that any process waiting on a buffer gets woken up.
- *
- * Waking up up the first buffer on the irq list is not enough, as the
- * process waiting on the buffer might restart the dequeue operation
- * immediately.
- *
+ * Video buffers are managed by videobuf2. The driver uses a mutex to protect
+ * the videobuf2 queue operations by serializing calls to videobuf2 and a
+ * spinlock to protect the IRQ queue that holds the buffers to be processed by
+ * the driver.
*/
-static void
-uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type)
-{
- mutex_init(&queue->mutex);
- spin_lock_init(&queue->irqlock);
- INIT_LIST_HEAD(&queue->mainqueue);
- INIT_LIST_HEAD(&queue->irqqueue);
- queue->type = type;
-}
-
-/*
- * Free the video buffers.
- *
- * This function must be called with the queue lock held.
+/* -----------------------------------------------------------------------------
+ * videobuf2 queue operations
*/
-static int uvc_free_buffers(struct uvc_video_queue *queue)
+
+static int uvc_queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
+ unsigned int *nbuffers, unsigned int *nplanes,
+ unsigned int sizes[], void *alloc_ctxs[])
{
- unsigned int i;
+ struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+ struct uvc_video *video = container_of(queue, struct uvc_video, queue);
- for (i = 0; i < queue->count; ++i) {
- if (queue->buffer[i].vma_use_count != 0)
- return -EBUSY;
- }
+ if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)
+ *nbuffers = UVC_MAX_VIDEO_BUFFERS;
- if (queue->count) {
- vfree(queue->mem);
- queue->count = 0;
- }
+ *nplanes = 1;
+
+ sizes[0] = video->imagesize;
return 0;
}
-/*
- * Allocate the video buffers.
- *
- * Pages are reserved to make sure they will not be swapped, as they will be
- * filled in the URB completion handler.
- *
- * Buffers will be individually mapped, so they must all be page aligned.
- */
-static int
-uvc_alloc_buffers(struct uvc_video_queue *queue, unsigned int nbuffers,
- unsigned int buflength)
+static int uvc_buffer_prepare(struct vb2_buffer *vb)
{
- unsigned int bufsize = PAGE_ALIGN(buflength);
- unsigned int i;
- void *mem = NULL;
- int ret;
+ struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
+ struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
- if (nbuffers > UVC_MAX_VIDEO_BUFFERS)
- nbuffers = UVC_MAX_VIDEO_BUFFERS;
+ if (vb->v4l2_buf.type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
+ vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
+ uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
+ return -EINVAL;
+ }
- mutex_lock(&queue->mutex);
+ if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
+ return -ENODEV;
- if ((ret = uvc_free_buffers(queue)) < 0)
- goto done;
+ buf->state = UVC_BUF_STATE_QUEUED;
+ buf->mem = vb2_plane_vaddr(vb, 0);
+ buf->length = vb2_plane_size(vb, 0);
+ if (vb->v4l2_buf.type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+ buf->bytesused = 0;
+ else
+ buf->bytesused = vb2_get_plane_payload(vb, 0);
- /* Bail out if no buffers should be allocated. */
- if (nbuffers == 0)
- goto done;
+ return 0;
+}
- /* Decrement the number of buffers until allocation succeeds. */
- for (; nbuffers > 0; --nbuffers) {
- mem = vmalloc_32(nbuffers * bufsize);
- if (mem != NULL)
- break;
- }
+static void uvc_buffer_queue(struct vb2_buffer *vb)
+{
+ struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
+ struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
+ unsigned long flags;
- if (mem == NULL) {
- ret = -ENOMEM;
- goto done;
- }
+ spin_lock_irqsave(&queue->irqlock, flags);
- for (i = 0; i < nbuffers; ++i) {
- memset(&queue->buffer[i], 0, sizeof queue->buffer[i]);
- queue->buffer[i].buf.index = i;
- queue->buffer[i].buf.m.offset = i * bufsize;
- queue->buffer[i].buf.length = buflength;
- queue->buffer[i].buf.type = queue->type;
- queue->buffer[i].buf.sequence = 0;
- queue->buffer[i].buf.field = V4L2_FIELD_NONE;
- queue->buffer[i].buf.memory = V4L2_MEMORY_MMAP;
- queue->buffer[i].buf.flags = 0;
- init_waitqueue_head(&queue->buffer[i].wait);
+ if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
+ list_add_tail(&buf->queue, &queue->irqqueue);
+ } else {
+ /* If the device is disconnected return the buffer to userspace
+ * directly. The next QBUF call will fail with -ENODEV.
+ */
+ buf->state = UVC_BUF_STATE_ERROR;
+ vb2_buffer_done(&buf->buf, VB2_BUF_STATE_ERROR);
}
- queue->mem = mem;
- queue->count = nbuffers;
- queue->buf_size = bufsize;
- ret = nbuffers;
-
-done:
- mutex_unlock(&queue->mutex);
- return ret;
+ spin_unlock_irqrestore(&queue->irqlock, flags);
}
-static void __uvc_query_buffer(struct uvc_buffer *buf,
- struct v4l2_buffer *v4l2_buf)
-{
- memcpy(v4l2_buf, &buf->buf, sizeof *v4l2_buf);
-
- if (buf->vma_use_count)
- v4l2_buf->flags |= V4L2_BUF_FLAG_MAPPED;
-
- switch (buf->state) {
- case UVC_BUF_STATE_ERROR:
- case UVC_BUF_STATE_DONE:
- v4l2_buf->flags |= V4L2_BUF_FLAG_DONE;
- break;
- case UVC_BUF_STATE_QUEUED:
- case UVC_BUF_STATE_ACTIVE:
- v4l2_buf->flags |= V4L2_BUF_FLAG_QUEUED;
- break;
- case UVC_BUF_STATE_IDLE:
- default:
- break;
- }
-}
+static struct vb2_ops uvc_queue_qops = {
+ .queue_setup = uvc_queue_setup,
+ .buf_prepare = uvc_buffer_prepare,
+ .buf_queue = uvc_buffer_queue,
+};
-static int
-uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *v4l2_buf)
+static int uvc_queue_init(struct uvc_video_queue *queue,
+ enum v4l2_buf_type type)
{
- int ret = 0;
+ int ret;
- mutex_lock(&queue->mutex);
- if (v4l2_buf->index >= queue->count) {
- ret = -EINVAL;
- goto done;
- }
+ queue->queue.type = type;
+ queue->queue.io_modes = VB2_MMAP | VB2_USERPTR;
+ queue->queue.drv_priv = queue;
+ queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
+ queue->queue.ops = &uvc_queue_qops;
+ queue->queue.mem_ops = &vb2_vmalloc_memops;
+ ret = vb2_queue_init(&queue->queue);
+ if (ret)
+ return ret;
+
+ mutex_init(&queue->mutex);
+ spin_lock_init(&queue->irqlock);
+ INIT_LIST_HEAD(&queue->irqqueue);
+ queue->flags = 0;
- __uvc_query_buffer(&queue->buffer[v4l2_buf->index], v4l2_buf);
+ return 0;
+}
-done:
+/*
+ * Free the video buffers.
+ */
+static void uvc_free_buffers(struct uvc_video_queue *queue)
+{
+ mutex_lock(&queue->mutex);
+ vb2_queue_release(&queue->queue);
mutex_unlock(&queue->mutex);
- return ret;
}
/*
- * Queue a video buffer. Attempting to queue a buffer that has already been
- * queued will return -EINVAL.
+ * Allocate the video buffers.
*/
-static int
-uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *v4l2_buf)
+static int uvc_alloc_buffers(struct uvc_video_queue *queue,
+ struct v4l2_requestbuffers *rb)
{
- struct uvc_buffer *buf;
- unsigned long flags;
- int ret = 0;
+ int ret;
- uvc_trace(UVC_TRACE_CAPTURE, "Queuing buffer %u.\n", v4l2_buf->index);
+ mutex_lock(&queue->mutex);
+ ret = vb2_reqbufs(&queue->queue, rb);
+ mutex_unlock(&queue->mutex);
- if (v4l2_buf->type != queue->type ||
- v4l2_buf->memory != V4L2_MEMORY_MMAP) {
- uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer type (%u) "
- "and/or memory (%u).\n", v4l2_buf->type,
- v4l2_buf->memory);
- return -EINVAL;
- }
+ return ret ? ret : rb->count;
+}
- mutex_lock(&queue->mutex);
- if (v4l2_buf->index >= queue->count) {
- uvc_trace(UVC_TRACE_CAPTURE, "[E] Out of range index.\n");
- ret = -EINVAL;
- goto done;
- }
+static int uvc_query_buffer(struct uvc_video_queue *queue,
+ struct v4l2_buffer *buf)
+{
+ int ret;
- buf = &queue->buffer[v4l2_buf->index];
- if (buf->state != UVC_BUF_STATE_IDLE) {
- uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer state "
- "(%u).\n", buf->state);
- ret = -EINVAL;
- goto done;
- }
+ mutex_lock(&queue->mutex);
+ ret = vb2_querybuf(&queue->queue, buf);
+ mutex_unlock(&queue->mutex);
- if (v4l2_buf->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
- v4l2_buf->bytesused > buf->buf.length) {
- uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
- ret = -EINVAL;
- goto done;
- }
+ return ret;
+}
- if (v4l2_buf->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
- buf->buf.bytesused = 0;
- else
- buf->buf.bytesused = v4l2_buf->bytesused;
+static int uvc_queue_buffer(struct uvc_video_queue *queue,
+ struct v4l2_buffer *buf)
+{
+ unsigned long flags;
+ int ret;
+ mutex_lock(&queue->mutex);
+ ret = vb2_qbuf(&queue->queue, buf);
spin_lock_irqsave(&queue->irqlock, flags);
- if (queue->flags & UVC_QUEUE_DISCONNECTED) {
- spin_unlock_irqrestore(&queue->irqlock, flags);
- ret = -ENODEV;
- goto done;
- }
- buf->state = UVC_BUF_STATE_QUEUED;
-
ret = (queue->flags & UVC_QUEUE_PAUSED) != 0;
queue->flags &= ~UVC_QUEUE_PAUSED;
-
- list_add_tail(&buf->stream, &queue->mainqueue);
- list_add_tail(&buf->queue, &queue->irqqueue);
spin_unlock_irqrestore(&queue->irqlock, flags);
-
-done:
mutex_unlock(&queue->mutex);
- return ret;
-}
-
-static int uvc_queue_waiton(struct uvc_buffer *buf, int nonblocking)
-{
- if (nonblocking) {
- return (buf->state != UVC_BUF_STATE_QUEUED &&
- buf->state != UVC_BUF_STATE_ACTIVE)
- ? 0 : -EAGAIN;
- }
- return wait_event_interruptible(buf->wait,
- buf->state != UVC_BUF_STATE_QUEUED &&
- buf->state != UVC_BUF_STATE_ACTIVE);
+ return ret;
}
/*
* Dequeue a video buffer. If nonblocking is false, block until a buffer is
* available.
*/
-static int
-uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *v4l2_buf,
- int nonblocking)
+static int uvc_dequeue_buffer(struct uvc_video_queue *queue,
+ struct v4l2_buffer *buf, int nonblocking)
{
- struct uvc_buffer *buf;
- int ret = 0;
-
- if (v4l2_buf->type != queue->type ||
- v4l2_buf->memory != V4L2_MEMORY_MMAP) {
- uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer type (%u) "
- "and/or memory (%u).\n", v4l2_buf->type,
- v4l2_buf->memory);
- return -EINVAL;
- }
+ int ret;
mutex_lock(&queue->mutex);
- if (list_empty(&queue->mainqueue)) {
- uvc_trace(UVC_TRACE_CAPTURE, "[E] Empty buffer queue.\n");
- ret = -EINVAL;
- goto done;
- }
-
- buf = list_first_entry(&queue->mainqueue, struct uvc_buffer, stream);
- if ((ret = uvc_queue_waiton(buf, nonblocking)) < 0)
- goto done;
-
- uvc_trace(UVC_TRACE_CAPTURE, "Dequeuing buffer %u (%u, %u bytes).\n",
- buf->buf.index, buf->state, buf->buf.bytesused);
-
- switch (buf->state) {
- case UVC_BUF_STATE_ERROR:
- uvc_trace(UVC_TRACE_CAPTURE, "[W] Corrupted data "
- "(transmission error).\n");
- ret = -EIO;
- case UVC_BUF_STATE_DONE:
- buf->state = UVC_BUF_STATE_IDLE;
- break;
-
- case UVC_BUF_STATE_IDLE:
- case UVC_BUF_STATE_QUEUED:
- case UVC_BUF_STATE_ACTIVE:
- default:
- uvc_trace(UVC_TRACE_CAPTURE, "[E] Invalid buffer state %u "
- "(driver bug?).\n", buf->state);
- ret = -EINVAL;
- goto done;
- }
-
- list_del(&buf->stream);
- __uvc_query_buffer(buf, v4l2_buf);
-
-done:
+ ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
mutex_unlock(&queue->mutex);
+
return ret;
}
* This function implements video queue polling and is intended to be used by
* the device poll handler.
*/
-static unsigned int
-uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
- poll_table *wait)
+static unsigned int uvc_queue_poll(struct uvc_video_queue *queue,
+ struct file *file, poll_table *wait)
{
- struct uvc_buffer *buf;
- unsigned int mask = 0;
+ unsigned int ret;
mutex_lock(&queue->mutex);
- if (list_empty(&queue->mainqueue))
- goto done;
-
- buf = list_first_entry(&queue->mainqueue, struct uvc_buffer, stream);
-
- poll_wait(file, &buf->wait, wait);
- if (buf->state == UVC_BUF_STATE_DONE ||
- buf->state == UVC_BUF_STATE_ERROR)
- mask |= POLLOUT | POLLWRNORM;
-
-done:
+ ret = vb2_poll(&queue->queue, file, wait);
mutex_unlock(&queue->mutex);
- return mask;
-}
-/*
- * VMA operations.
- */
-static void uvc_vm_open(struct vm_area_struct *vma)
-{
- struct uvc_buffer *buffer = vma->vm_private_data;
- buffer->vma_use_count++;
-}
-
-static void uvc_vm_close(struct vm_area_struct *vma)
-{
- struct uvc_buffer *buffer = vma->vm_private_data;
- buffer->vma_use_count--;
+ return ret;
}
-static struct vm_operations_struct uvc_vm_ops = {
- .open = uvc_vm_open,
- .close = uvc_vm_close,
-};
-
-/*
- * Memory-map a buffer.
- *
- * This function implements video buffer memory mapping and is intended to be
- * used by the device mmap handler.
- */
-static int
-uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
+static int uvc_queue_mmap(struct uvc_video_queue *queue,
+ struct vm_area_struct *vma)
{
- struct uvc_buffer *uninitialized_var(buffer);
- struct page *page;
- unsigned long addr, start, size;
- unsigned int i;
- int ret = 0;
-
- start = vma->vm_start;
- size = vma->vm_end - vma->vm_start;
+ int ret;
mutex_lock(&queue->mutex);
-
- for (i = 0; i < queue->count; ++i) {
- buffer = &queue->buffer[i];
- if ((buffer->buf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff)
- break;
- }
-
- if (i == queue->count || size != queue->buf_size) {
- ret = -EINVAL;
- goto done;
- }
-
- /*
- * VM_IO marks the area as being an mmaped region for I/O to a
- * device. It also prevents the region from being core dumped.
- */
- vma->vm_flags |= VM_IO;
-
- addr = (unsigned long)queue->mem + buffer->buf.m.offset;
- while (size > 0) {
- page = vmalloc_to_page((void *)addr);
- if ((ret = vm_insert_page(vma, start, page)) < 0)
- goto done;
-
- start += PAGE_SIZE;
- addr += PAGE_SIZE;
- size -= PAGE_SIZE;
- }
-
- vma->vm_ops = &uvc_vm_ops;
- vma->vm_private_data = buffer;
- uvc_vm_open(vma);
-
-done:
+ ret = vb2_mmap(&queue->queue, vma);
mutex_unlock(&queue->mutex);
+
return ret;
}
queue);
list_del(&buf->queue);
buf->state = UVC_BUF_STATE_ERROR;
- wake_up(&buf->wait);
+ vb2_buffer_done(&buf->buf, VB2_BUF_STATE_ERROR);
}
/* This must be protected by the irqlock spinlock to avoid race
* conditions between uvc_queue_buffer and the disconnection event that
*/
static int uvc_queue_enable(struct uvc_video_queue *queue, int enable)
{
- unsigned int i;
+ unsigned long flags;
int ret = 0;
mutex_lock(&queue->mutex);
if (enable) {
- if (uvc_queue_streaming(queue)) {
- ret = -EBUSY;
+ ret = vb2_streamon(&queue->queue, queue->queue.type);
+ if (ret < 0)
goto done;
- }
+
queue->sequence = 0;
- queue->flags |= UVC_QUEUE_STREAMING;
queue->buf_used = 0;
} else {
- uvc_queue_cancel(queue, 0);
- INIT_LIST_HEAD(&queue->mainqueue);
+ ret = vb2_streamoff(&queue->queue, queue->queue.type);
+ if (ret < 0)
+ goto done;
- for (i = 0; i < queue->count; ++i)
- queue->buffer[i].state = UVC_BUF_STATE_IDLE;
+ spin_lock_irqsave(&queue->irqlock, flags);
+ INIT_LIST_HEAD(&queue->irqqueue);
- queue->flags &= ~UVC_QUEUE_STREAMING;
+ /*
+ * FIXME: We need to clear the DISCONNECTED flag to ensure that
+ * applications will be able to queue buffers for the next
+ * streaming run. However, clearing it here doesn't guarantee
+ * that the device will be reconnected in the meantime.
+ */
+ queue->flags &= ~UVC_QUEUE_DISCONNECTED;
+ spin_unlock_irqrestore(&queue->irqlock, flags);
}
done:
}
/* called with &queue_irqlock held.. */
-static struct uvc_buffer *
-uvc_queue_next_buffer(struct uvc_video_queue *queue, struct uvc_buffer *buf)
+static struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
+ struct uvc_buffer *buf)
{
struct uvc_buffer *nextbuf;
if ((queue->flags & UVC_QUEUE_DROP_INCOMPLETE) &&
- buf->buf.length != buf->buf.bytesused) {
+ buf->length != buf->bytesused) {
buf->state = UVC_BUF_STATE_QUEUED;
- buf->buf.bytesused = 0;
+ vb2_set_plane_payload(&buf->buf, 0, 0);
return buf;
}
else
nextbuf = NULL;
- buf->buf.sequence = queue->sequence++;
- do_gettimeofday(&buf->buf.timestamp);
+ /*
+ * FIXME: with videobuf2, the sequence number or timestamp fields
+ * are valid only for video capture devices and the UVC gadget usually
+ * is a video output device. Keeping these until the specs are clear on
+ * this aspect.
+ */
+ buf->buf.v4l2_buf.sequence = queue->sequence++;
+ do_gettimeofday(&buf->buf.v4l2_buf.timestamp);
+
+ vb2_set_plane_payload(&buf->buf, 0, buf->bytesused);
+ vb2_buffer_done(&buf->buf, VB2_BUF_STATE_DONE);
- wake_up(&buf->wait);
return nextbuf;
}
projects / platform / kernel / linux-rpi.git / blobdiff