1 files changed, 407 insertions, 0 deletions

diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c
new file mode 100644
index 000000000000..1c29bc954db9
--- /dev/null
+++ b/drivers/usb/gadget/function/uvc_queue.c
@@ -0,0 +1,407 @@
+/*
+ *      uvc_queue.c  --  USB Video Class driver - Buffers management
+ *
+ *      Copyright (C) 2005-2010
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.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; either version 2 of the License, or
+ *      (at your option) any later version.
+ */
+
+#include <linux/atomic.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+
+#include <media/v4l2-common.h>
+#include <media/videobuf2-vmalloc.h>
+
+#include "uvc.h"
+
+/* ------------------------------------------------------------------------
+ * Video buffers queue management.
+ *
+ * Video queues is initialized by uvc_queue_init(). The function performs
+ * basic initialization of the uvc_video_queue struct and never fails.
+ *
+ * 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.
+ */
+
+/* -----------------------------------------------------------------------------
+ * videobuf2 queue operations
+ */
+
+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[])
+{
+        struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+        struct uvc_video *video = container_of(queue, struct uvc_video, queue);
+
+        if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)
+                *nbuffers = UVC_MAX_VIDEO_BUFFERS;
+
+        *nplanes = 1;
+
+        sizes[0] = video->imagesize;
+
+        return 0;
+}
+
+static int uvc_buffer_prepare(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);
+
+        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;
+        }
+
+        if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
+                return -ENODEV;
+
+        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);
+
+        return 0;
+}
+
+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;
+
+        spin_lock_irqsave(&queue->irqlock, flags);
+
+        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);
+        }
+
+        spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+static void uvc_wait_prepare(struct vb2_queue *vq)
+{
+        struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+
+        mutex_unlock(&queue->mutex);
+}
+
+static void uvc_wait_finish(struct vb2_queue *vq)
+{
+        struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+
+        mutex_lock(&queue->mutex);
+}
+
+static struct vb2_ops uvc_queue_qops = {
+        .queue_setup = uvc_queue_setup,
+        .buf_prepare = uvc_buffer_prepare,
+        .buf_queue = uvc_buffer_queue,
+        .wait_prepare = uvc_wait_prepare,
+        .wait_finish = uvc_wait_finish,
+};
+
+static int uvc_queue_init(struct uvc_video_queue *queue,
+                          enum v4l2_buf_type type)
+{
+        int ret;
+
+        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;
+        queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
+                                     | V4L2_BUF_FLAG_TSTAMP_SRC_EOF;
+        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;
+
+        return 0;
+}
+
+/*
+ * 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);
+}
+
+/*
+ * Allocate the video buffers.
+ */
+static int uvc_alloc_buffers(struct uvc_video_queue *queue,
+                             struct v4l2_requestbuffers *rb)
+{
+        int ret;
+
+        mutex_lock(&queue->mutex);
+        ret = vb2_reqbufs(&queue->queue, rb);
+        mutex_unlock(&queue->mutex);
+
+        return ret ? ret : rb->count;
+}
+
+static int uvc_query_buffer(struct uvc_video_queue *queue,
+                            struct v4l2_buffer *buf)
+{
+        int ret;
+
+        mutex_lock(&queue->mutex);
+        ret = vb2_querybuf(&queue->queue, buf);
+        mutex_unlock(&queue->mutex);
+
+        return ret;
+}
+
+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);
+        if (ret < 0)
+                goto done;
+
+        spin_lock_irqsave(&queue->irqlock, flags);
+        ret = (queue->flags & UVC_QUEUE_PAUSED) != 0;
+        queue->flags &= ~UVC_QUEUE_PAUSED;
+        spin_unlock_irqrestore(&queue->irqlock, flags);
+
+done:
+        mutex_unlock(&queue->mutex);
+        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 *buf, int nonblocking)
+{
+        int ret;
+
+        mutex_lock(&queue->mutex);
+        ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
+        mutex_unlock(&queue->mutex);
+
+        return ret;
+}
+
+/*
+ * Poll the video queue.
+ *
+ * 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)
+{
+        unsigned int ret;
+
+        mutex_lock(&queue->mutex);
+        ret = vb2_poll(&queue->queue, file, wait);
+        mutex_unlock(&queue->mutex);
+
+        return ret;
+}
+
+static int uvc_queue_mmap(struct uvc_video_queue *queue,
+                          struct vm_area_struct *vma)
+{
+        int ret;
+
+        mutex_lock(&queue->mutex);
+        ret = vb2_mmap(&queue->queue, vma);
+        mutex_unlock(&queue->mutex);
+
+        return ret;
+}
+
+#ifndef CONFIG_MMU
+/*
+ * Get unmapped area.
+ *
+ * NO-MMU arch need this function to make mmap() work correctly.
+ */
+static unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
+                unsigned long pgoff)
+{
+        unsigned long ret;
+
+        mutex_lock(&queue->mutex);
+        ret = vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
+        mutex_unlock(&queue->mutex);
+        return ret;
+}
+#endif
+
+/*
+ * Cancel the video buffers queue.
+ *
+ * Cancelling the queue marks all buffers on the irq queue as erroneous,
+ * wakes them up and removes them from the queue.
+ *
+ * If the disconnect parameter is set, further calls to uvc_queue_buffer will
+ * fail with -ENODEV.
+ *
+ * This function acquires the irq spinlock and can be called from interrupt
+ * context.
+ */
+static void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
+{
+        struct uvc_buffer *buf;
+        unsigned long flags;
+
+        spin_lock_irqsave(&queue->irqlock, flags);
+        while (!list_empty(&queue->irqqueue)) {
+                buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+                                       queue);
+                list_del(&buf->queue);
+                buf->state = UVC_BUF_STATE_ERROR;
+                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
+         * could result in an interruptible wait in uvc_dequeue_buffer. Do not
+         * blindly replace this logic by checking for the UVC_DEV_DISCONNECTED
+         * state outside the queue code.
+         */
+        if (disconnect)
+                queue->flags |= UVC_QUEUE_DISCONNECTED;
+        spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+/*
+ * Enable or disable the video buffers queue.
+ *
+ * The queue must be enabled before starting video acquisition and must be
+ * disabled after stopping it. This ensures that the video buffers queue
+ * state can be properly initialized before buffers are accessed from the
+ * interrupt handler.
+ *
+ * Enabling the video queue initializes parameters (such as sequence number,
+ * sync pattern, ...). If the queue is already enabled, return -EBUSY.
+ *
+ * Disabling the video queue cancels the queue and removes all buffers from
+ * the main queue.
+ *
+ * This function can't be called from interrupt context. Use
+ * uvc_queue_cancel() instead.
+ */
+static int uvc_queue_enable(struct uvc_video_queue *queue, int enable)
+{
+        unsigned long flags;
+        int ret = 0;
+
+        mutex_lock(&queue->mutex);
+        if (enable) {
+                ret = vb2_streamon(&queue->queue, queue->queue.type);
+                if (ret < 0)
+                        goto done;
+
+                queue->sequence = 0;
+                queue->buf_used = 0;
+        } else {
+                ret = vb2_streamoff(&queue->queue, queue->queue.type);
+                if (ret < 0)
+                        goto done;
+
+                spin_lock_irqsave(&queue->irqlock, flags);
+                INIT_LIST_HEAD(&queue->irqqueue);
+
+                /*
+                 * 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:
+        mutex_unlock(&queue->mutex);
+        return ret;
+}
+
+/* called with &queue_irqlock held.. */
+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->length != buf->bytesused) {
+                buf->state = UVC_BUF_STATE_QUEUED;
+                vb2_set_plane_payload(&buf->buf, 0, 0);
+                return buf;
+        }
+
+        list_del(&buf->queue);
+        if (!list_empty(&queue->irqqueue))
+                nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+                                           queue);
+        else
+                nextbuf = NULL;
+
+        buf->buf.v4l2_buf.field = V4L2_FIELD_NONE;
+        buf->buf.v4l2_buf.sequence = queue->sequence++;
+        v4l2_get_timestamp(&buf->buf.v4l2_buf.timestamp);
+
+        vb2_set_plane_payload(&buf->buf, 0, buf->bytesused);
+        vb2_buffer_done(&buf->buf, VB2_BUF_STATE_DONE);
+
+        return nextbuf;
+}
+
+static struct uvc_buffer *uvc_queue_head(struct uvc_video_queue *queue)
+{
+        struct uvc_buffer *buf = NULL;
+
+        if (!list_empty(&queue->irqqueue))
+                buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+                                       queue);
+        else
+                queue->flags |= UVC_QUEUE_PAUSED;
+
+        return buf;
+}
+