Split UVC gadget into a library and test application

Split the project into a UVC gadget library and a test application. To
avoid rolling out a custom build system, switch to CMake.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

6 files changed, 440 insertions, 0 deletions

diff --git a/include/uvcgadget/configfs.h b/include/uvcgadget/configfs.h
new file mode 100644
index 0000000..e5a7efa
--- /dev/null
+++ b/include/uvcgadget/configfs.h
@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * ConfigFS Gadget device handling
+ *
+ * Copyright (C) 2018 Kieran Bingham
+ *
+ * Contact: Kieran Bingham <kieran.bingham@ideasonboard.com>
+ */
+
+#ifndef __CONFIGFS_H__
+#define __CONFIGFS_H__
+
+#include <stdint.h>
+
+/*
+ * struct uvc_function_config_endpoint - Endpoint parameters
+ * @bInterval: Transfer interval (interrupt and isochronous only)
+ * @bMaxBurst: Transfer burst size (super-speed only)
+ * @wMaxPacketSize: Maximum packet size (including the multiplier)
+ */
+struct uvc_function_config_endpoint {
+	unsigned int bInterval;
+	unsigned int bMaxBurst;
+	unsigned int wMaxPacketSize;
+};
+
+/*
+ * struct uvc_function_config_interface - Interface parameters
+ * @bInterfaceNumber: Interface number
+ */
+struct uvc_function_config_interface {
+	unsigned int bInterfaceNumber;
+};
+
+/*
+ * struct uvc_function_config_control - Control interface parameters
+ * @intf: Generic interface parameters
+ */
+struct uvc_function_config_control {
+	struct uvc_function_config_interface intf;
+};
+
+/*
+ * struct uvc_function_config_frame - Streaming frame parameters
+ * @index: Frame index in the UVC descriptors
+ * @width: Frame width in pixels
+ * @height: Frame height in pixels
+ * @num_intervals: Number of entries in the intervals array
+ * @intervals: Array of frame intervals
+ */
+struct uvc_function_config_frame {
+	unsigned int index;
+	unsigned int width;
+	unsigned int height;
+	unsigned int num_intervals;
+	unsigned int *intervals;
+};
+
+/*
+ * struct uvc_function_config_format - Streaming format parameters
+ * @index: Format index in the UVC descriptors
+ * @guid: Format GUID
+ * @fcc: V4L2 pixel format
+ * @num_frames: Number of entries in the frames array
+ * @frames: Array of frame descriptors
+ */
+struct uvc_function_config_format {
+	unsigned int index;
+	uint8_t guid[16];
+	unsigned int fcc;
+	unsigned int num_frames;
+	struct uvc_function_config_frame *frames;
+};
+
+/*
+ * struct uvc_function_config_streaming - Streaming interface parameters
+ * @intf: Generic interface parameters
+ * @ep: Endpoint parameters
+ * @num_formats: Number of entries in the formats array
+ * @formats: Array of format descriptors
+ */
+struct uvc_function_config_streaming {
+	struct uvc_function_config_interface intf;
+	struct uvc_function_config_endpoint ep;
+
+	unsigned int num_formats;
+	struct uvc_function_config_format *formats;
+};
+
+/*
+ * struct uvc_function_config - UVC function configuration parameters
+ * @video: Full path to the video device node
+ * @udc: UDC name
+ * @control: Control interface configuration
+ * @streaming: Streaming interface configuration
+ */
+struct uvc_function_config {
+	char *video;
+	char *udc;
+
+	struct uvc_function_config_control control;
+	struct uvc_function_config_streaming streaming;
+};
+
+struct uvc_function_config *configfs_parse_uvc_function(const char *function);
+void configfs_free_uvc_function(struct uvc_function_config *fc);
+
+#endif
diff --git a/include/uvcgadget/events.h b/include/uvcgadget/events.h
new file mode 100644
index 0000000..b0b8fa8
--- /dev/null
+++ b/include/uvcgadget/events.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Generic Event Handling
+ *
+ * Copyright (C) 2018 Laurent Pinchart
+ *
+ * This file comes from the omap3-isp-live project
+ * (git://git.ideasonboard.org/omap3-isp-live.git)
+ *
+ * Copyright (C) 2010-2011 Ideas on board SPRL
+ *
+ * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ */
+
+#ifndef __EVENTS_H__
+#define __EVENTS_H__
+
+#include <stdbool.h>
+#include <sys/select.h>
+
+#include "list.h"
+
+struct events {
+	struct list_entry events;
+	bool done;
+
+	int maxfd;
+	fd_set rfds;
+	fd_set wfds;
+	fd_set efds;
+};
+
+enum event_type {
+	EVENT_READ = 1,
+	EVENT_WRITE = 2,
+	EVENT_EXCEPTION = 4,
+};
+
+void events_watch_fd(struct events *events, int fd, enum event_type type,
+		     void(*callback)(void *), void *priv);
+void events_unwatch_fd(struct events *events, int fd, enum event_type type);
+
+bool events_loop(struct events *events);
+void events_stop(struct events *events);
+
+void events_init(struct events *events);
+void events_cleanup(struct events *events);
+
+#endif
diff --git a/include/uvcgadget/list.h b/include/uvcgadget/list.h
new file mode 100644
index 0000000..8854c6e
--- /dev/null
+++ b/include/uvcgadget/list.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Double Linked Lists
+ *
+ * Copyright (C) 2018 Laurent Pinchart
+ *
+ * This file comes from the omap3-isp-live project
+ * (git://git.ideasonboard.org/omap3-isp-live.git)
+ *
+ * Copyright (C) 2010-2011 Ideas on board SPRL
+ *
+ * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ */
+
+#ifndef __LIST_H
+#define __LIST_H
+
+#include <stddef.h>
+
+struct list_entry {
+	struct list_entry *prev;
+	struct list_entry *next;
+};
+
+static inline void list_init(struct list_entry *list)
+{
+	list->next = list;
+	list->prev = list;
+}
+
+static inline int list_empty(struct list_entry *list)
+{
+	return list->next == list;
+}
+
+static inline void list_append(struct list_entry *entry, struct list_entry *list)
+{
+	entry->next = list;
+	entry->prev = list->prev;
+	list->prev->next = entry;
+	list->prev = entry;
+}
+
+static inline void list_prepend(struct list_entry *entry, struct list_entry *list)
+{
+	entry->next = list->next;
+	entry->prev = list;
+	list->next->prev = entry;
+	list->next = entry;
+}
+
+static inline void list_insert_after(struct list_entry *entry, struct list_entry *after)
+{
+	list_prepend(entry, after);
+}
+
+static inline void list_insert_before(struct list_entry *entry, struct list_entry *before)
+{
+	list_append(entry, before);
+}
+
+static inline void list_remove(struct list_entry *entry)
+{
+	entry->prev->next = entry->next;
+	entry->next->prev = entry->prev;
+}
+
+#define list_entry(entry, type, member) \
+	(type *)((char *)(entry) - offsetof(type, member))
+
+#define list_first_entry(list, type, member) \
+	list_entry((list)->next, type, member)
+
+#define list_last_entry(list, type, member) \
+	list_entry((list)->prev, type, member)
+
+#define list_for_each(entry, list) \
+	for (entry = (list)->next; entry != (list); entry = entry->next)
+
+#define list_for_each_entry(entry, list, member) \
+	for (entry = list_entry((list)->next, typeof(*entry), member); \
+	     &entry->member != (list); \
+	     entry = list_entry(entry->member.next, typeof(*entry), member))
+
+#define list_for_each_safe(entry, __next, list) \
+	for (entry = (list)->next, __next = entry->next; entry != (list); \
+	     entry = __next, __next = entry->next)
+
+#define list_for_each_entry_safe(entry, __next, list, member) \
+	for (entry = list_entry((list)->next, typeof(*entry), member), \
+	     __next = list_entry(entry->member.next, typeof(*entry), member); \
+	     &entry->member != (list); \
+	     entry = __next, __next = list_entry(entry->member.next, typeof(*entry), member))
+
+#endif /* __LIST_H */
diff --git a/include/uvcgadget/stream.h b/include/uvcgadget/stream.h
new file mode 100644
index 0000000..13779d3
--- /dev/null
+++ b/include/uvcgadget/stream.h
@@ -0,0 +1,113 @@
+/*
+ * 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.,
+ */
+
+#ifndef __STREAM_H__
+#define __STREAM_H__
+
+struct events;
+struct uvc_function_config;
+struct uvc_stream;
+struct v4l2_pix_format;
+struct video_source;
+
+/*
+ * uvc_stream_new - Create a new UVC stream
+ * @uvc_device: Filename of UVC device node
+ *
+ * Create a new UVC stream to handle the UVC function corresponding to the video
+ * device node @uvc_device.
+ *
+ * Streams allocated with this function can be deleted with uvc_stream_delete().
+ *
+ * On success, returns a pointer to newly allocated and populated struct uvc_stream.
+ * On failure, returns NULL.
+ */
+struct uvc_stream *uvc_stream_new(const char *uvc_device);
+
+/*
+ * uvc_stream_init_uvc - Initialize a UVC stream
+ * @stream: the UVC stream
+ * @fc: UVC function configuration
+ *
+ * Before it can be used, a UVC stream has to be initialized by calling this
+ * function with a UVC function configuration @fc. The function configuration
+ * contains all the parameters of the UVC function that will be handled by the
+ * UVC stream. It can be parsed from the UVC function ConfigFS directory using
+ * configfs_parse_uvc_function().
+ *
+ * uvc_stream_init_uvc() also registers UVC event notifiers for the stream. The
+ * caller must have called the uvc_stream_set_event_handler() function first,
+ * and ensure that the event handler is immediately usable. If the event loop is
+ * already running, all initialization steps required to handle events must be
+ * fully performed before calling this function.
+ */
+void uvc_stream_init_uvc(struct uvc_stream *stream,
+			 struct uvc_function_config *fc);
+
+/*
+ * uvc_stream_set_event_handler - Set an event handler for a stream
+ * @stream: the UVC stream
+ * @events: the event handler
+ *
+ * This function sets the event handler that the stream can use to be notified
+ * of file descriptor events.
+ */
+void uvc_stream_set_event_handler(struct uvc_stream *stream,
+				  struct events *events);
+
+void uvc_stream_set_video_source(struct uvc_stream *stream,
+				 struct video_source *src);
+
+/*
+ * uvc_stream_delete - Delete a UVC stream
+ * @stream: the UVC stream
+ *
+ * This functions deletes the @stream created with uvc_stream_new(). Upon return
+ * the stream object may be freed, the @stream pointer thus becomes invalid and
+ * the stream must not be touched anymore.
+ *
+ * Every stream allocated with uvc_stream_new() must be deleted when not needed
+ * anymore.
+ */
+void uvc_stream_delete(struct uvc_stream *stream);
+
+/*
+ * uvc_stream_set_format - Set the active video format for the stream
+ * @stream: the UVC stream
+ * @format: the video stream format
+ *
+ * This function is called from the UVC protocol handler to configure the video
+ * format for the @stream. It must not be called directly by applications.
+ *
+ * Returns 0 on success, or a negative error code on failure.
+ */
+int uvc_stream_set_format(struct uvc_stream *stream,
+			  const struct v4l2_pix_format *format);
+
+/*
+ * uvc_stream_enable - Turn on/off video streaming for the UVC stream
+ * @stream: the UVC stream
+ * @enable: 0 to stop the stream, 1 to start it
+ *
+ * This function is called from the UVC protocol handler to start video transfer
+ * for the @stream. It must not be called directly by applications.
+ */
+void uvc_stream_enable(struct uvc_stream *stream, int enable);
+
+#endif /* __STREAM_H__ */
diff --git a/include/uvcgadget/v4l2-source.h b/include/uvcgadget/v4l2-source.h
new file mode 100644
index 0000000..53e28d6
--- /dev/null
+++ b/include/uvcgadget/v4l2-source.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * V4L2 video source
+ *
+ * Copyright (C) 2018 Laurent Pinchart
+ *
+ * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ */
+#ifndef __V4L2_VIDEO_SOURCE_H__
+#define __V4L2_VIDEO_SOURCE_H__
+
+#include "video-source.h"
+
+struct events;
+struct video_source;
+
+struct video_source *v4l2_video_source_create(const char *devname);
+void v4l2_video_source_init(struct video_source *src, struct events *events);
+
+#endif /* __VIDEO_SOURCE_H__ */
diff --git a/include/uvcgadget/video-source.h b/include/uvcgadget/video-source.h
new file mode 100644
index 0000000..fffcba3
--- /dev/null
+++ b/include/uvcgadget/video-source.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Abstract video source
+ *
+ * Copyright (C) 2018 Laurent Pinchart
+ *
+ * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ */
+#ifndef __VIDEO_SOURCE_H__
+#define __VIDEO_SOURCE_H__
+
+struct v4l2_buffer;
+struct v4l2_pix_format;
+struct video_buffer;
+struct video_buffer_set;
+struct video_source;
+
+struct video_source_ops {
+	void(*destroy)(struct video_source *src);
+	int(*set_format)(struct video_source *src, struct v4l2_pix_format *fmt);
+	int(*alloc_buffers)(struct video_source *src, unsigned int nbufs);
+	int(*export_buffers)(struct video_source *src,
+			     struct video_buffer_set **buffers);
+	int(*free_buffers)(struct video_source *src);
+	int(*stream_on)(struct video_source *src);
+	int(*stream_off)(struct video_source *src);
+	int(*queue_buffer)(struct video_source *src, struct video_buffer *buf);
+};
+
+typedef void(*video_source_buffer_handler_t)(void *, struct video_source *,
+					     struct video_buffer *);
+
+struct video_source {
+	const struct video_source_ops *ops;
+	struct events *events;
+	video_source_buffer_handler_t handler;
+	void *handler_data;
+};
+
+void video_source_set_buffer_handler(struct video_source *src,
+				     video_source_buffer_handler_t handler,
+				     void *data);
+void video_source_destroy(struct video_source *src);
+int video_source_set_format(struct video_source *src,
+			    struct v4l2_pix_format *fmt);
+int video_source_alloc_buffers(struct video_source *src, unsigned int nbufs);
+int video_source_export_buffers(struct video_source *src,
+				struct video_buffer_set **buffers);
+int video_source_free_buffers(struct video_source *src);
+int video_source_stream_on(struct video_source *src);
+int video_source_stream_off(struct video_source *src);
+int video_source_queue_buffer(struct video_source *src,
+			      struct video_buffer *buf);
+
+#endif /* __VIDEO_SOURCE_H__ */