uvc-gadget: factor out uvc protocol and stream handling code

uvc-gadget.c has been getting cluttered with functions related to
UVC protocol handling and stream handling. Additionally, it is forseen
that we might want stream handling to be modular for different system
models. Factor out code related to UVC protocol handling to uvc.c (and
uvc.h) and code related to stream handling to stream.c (and stream.h),
and update the Makefile accordingly.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 250 insertions, 0 deletions

diff --git a/stream.c b/stream.c
new file mode 100644
index 0000000..b6e0efe
--- /dev/null
+++ b/stream.c
@@ -0,0 +1,250 @@
+/*
+ * UVC stream handling
+ *
+ * Copyright (C) 2010 Ideas on board SPRL <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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "events.h"
+#include "stream.h"
+#include "uvc.h"
+#include "v4l2.h"
+
+/* ---------------------------------------------------------------------------
+ * Video streaming
+ */
+
+static void capture_video_process(void *d)
+{
+	struct uvc_stream *stream = d;
+	struct v4l2_video_buffer buf;
+	int ret;
+
+	ret = v4l2_dequeue_buffer(stream->cap, &buf);
+	if (ret < 0)
+		return;
+
+	v4l2_queue_buffer(stream->uvc->vdev, &buf);
+}
+
+static void uvc_video_process(void *d)
+{
+	struct uvc_stream *stream = d;
+	struct v4l2_video_buffer buf;
+	int ret;
+
+	ret = v4l2_dequeue_buffer(stream->uvc->vdev, &buf);
+	if (ret < 0)
+		return;
+
+	v4l2_queue_buffer(stream->cap, &buf);
+}
+
+static int uvc_video_enable(struct uvc_stream *stream, int enable)
+{
+	struct v4l2_device *cap = stream->cap;
+	struct uvc_device *dev = stream->uvc;
+	int ret;
+
+	if (!enable) {
+		printf("Stopping video stream.\n");
+		events_unwatch_fd(stream->events, dev->vdev->fd, EVENT_WRITE);
+		v4l2_stream_off(dev->vdev);
+		v4l2_free_buffers(dev->vdev);
+		return 0;
+	}
+
+	printf("Starting video stream.\n");
+
+	ret = v4l2_alloc_buffers(dev->vdev, V4L2_MEMORY_DMABUF, 4);
+	if (ret < 0) {
+		printf("Failed to allocate buffers: %s (%d)\n", strerror(-ret), -ret);
+		return ret;
+	}
+
+	ret = v4l2_import_buffers(dev->vdev, dev->vdev->nbufs, cap->buffers);
+	if (ret < 0) {
+		printf("Failed to import buffers: %s (%d)\n", strerror(-ret), -ret);
+		goto error;
+	}
+
+	v4l2_stream_on(dev->vdev);
+	events_watch_fd(stream->events, dev->vdev->fd, EVENT_WRITE,
+			uvc_video_process, stream);
+
+	return 0;
+
+error:
+	v4l2_free_buffers(dev->vdev);
+	return ret;
+}
+
+static int capture_video_stream(struct uvc_stream *stream, int enable)
+{
+	struct v4l2_device *cap = stream->cap;
+	unsigned int i;
+	int ret;
+
+	if (!enable) {
+		printf("Stopping video capture stream.\n");
+		events_unwatch_fd(stream->events, cap->fd, EVENT_READ);
+		v4l2_stream_off(cap);
+		v4l2_free_buffers(cap);
+		return 0;
+	}
+
+	printf("Starting video capture stream.\n");
+
+	ret = v4l2_alloc_buffers(cap, V4L2_MEMORY_MMAP, 4);
+	if (ret < 0) {
+		printf("Failed to allocate capture buffers.\n");
+		return ret;
+	}
+
+	ret = v4l2_export_buffers(cap);
+	if (ret < 0) {
+		printf("Failed to export buffers.\n");
+		goto error;
+	}
+
+	for (i = 0; i < cap->nbufs; ++i) {
+		struct v4l2_video_buffer *buf = &cap->buffers[i];
+
+		ret = v4l2_queue_buffer(cap, buf);
+		if (ret < 0)
+			goto error;
+	}
+
+	v4l2_stream_on(cap);
+	events_watch_fd(stream->events, cap->fd, EVENT_READ,
+			capture_video_process, stream);
+
+	return 0;
+
+error:
+	v4l2_free_buffers(cap);
+	return ret;
+}
+
+void uvc_stream_enable(struct uvc_stream *stream, int enable)
+{
+	if (enable) {
+		capture_video_stream(stream, 1);
+		uvc_video_enable(stream, 1);
+	} else {
+		uvc_video_enable(stream, 0);
+		capture_video_stream(stream, 0);
+	}
+}
+
+int uvc_stream_set_format(struct uvc_stream *stream)
+{
+	struct v4l2_device *cap = stream->cap;
+	struct uvc_device *dev = stream->uvc;
+	struct v4l2_pix_format fmt;
+	int ret;
+
+	printf("Setting format to 0x%08x %ux%u\n",
+		dev->fcc, dev->width, dev->height);
+
+	memset(&fmt, 0, sizeof fmt);
+	fmt.width = dev->width;
+	fmt.height = dev->height;
+	fmt.pixelformat = dev->fcc;
+	fmt.field = V4L2_FIELD_NONE;
+	if (dev->fcc == V4L2_PIX_FMT_MJPEG)
+		fmt.sizeimage = dev->maxsize * 1.5;
+
+	ret = v4l2_set_format(dev->vdev, &fmt);
+	if (ret < 0)
+		return ret;
+
+	return v4l2_set_format(cap, &fmt);
+}
+
+static int uvc_video_init(struct uvc_device *dev __attribute__((__unused__)))
+{
+	return 0;
+}
+
+/* ---------------------------------------------------------------------------
+ * Stream handling
+ */
+
+struct uvc_stream *uvc_stream_new(const char *uvc_device,
+				  const char *cap_device)
+{
+	struct uvc_stream *stream;
+
+	stream = malloc(sizeof(*stream));
+	if (stream == NULL)
+		return NULL;
+
+	memset(stream, 0, sizeof(*stream));
+
+	stream->cap = v4l2_open(cap_device);
+	if (stream->cap == NULL)
+		goto error;
+
+	stream->uvc = uvc_open(uvc_device);
+	if (stream->uvc == NULL)
+		goto error;
+
+	return stream;
+
+error:
+	if (stream->cap)
+		v4l2_close(stream->cap);
+
+	free(stream);
+	return NULL;
+}
+
+void uvc_stream_delete(struct uvc_stream *stream)
+{
+	if (stream == NULL)
+		return;
+
+	v4l2_close(stream->cap);
+	uvc_close(stream->uvc);
+
+	free(stream);
+}
+
+void uvc_stream_init_uvc(struct uvc_stream *stream,
+			 struct uvc_function_config *fc)
+{
+	/*
+	 * FIXME: The maximum size should be specified per format and frame.
+	 */
+	stream->uvc->maxsize = 0;
+	stream->uvc->fc = fc;
+
+	uvc_events_init(stream->uvc);
+	uvc_video_init(stream->uvc);
+}
+
+void uvc_stream_set_event_handler(struct uvc_stream *stream,
+				  struct events *events)
+{
+	stream->events = events;
+
+	events_watch_fd(stream->events, stream->uvc->vdev->fd, EVENT_EXCEPTION,
+			uvc_events_process, stream);
+}