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>

1 files changed, 0 insertions, 846 deletions

diff --git a/configfs.c b/configfs.c
deleted file mode 100644
index 1dfde95..0000000
--- a/configfs.c
+++ /dev/null
@@ -1,846 +0,0 @@
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-/*
- * ConfigFS Gadget device handling
- *
- * Copyright (C) 2018 Kieran Bingham
- *
- * Contact: Kieran Bingham <kieran.bingham@ideasonboard.com>
- */
-
-/* To provide basename and asprintf from the GNU library. */
- #define _GNU_SOURCE
-
-#include <dirent.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <glob.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#include <linux/videodev2.h>
-
-#include "configfs.h"
-#include "tools.h"
-
-/* -----------------------------------------------------------------------------
- * Path handling and support
- */
-
-static char *path_join(const char *dirname, const char *name)
-{
-	char *path;
-
-	asprintf(&path, "%s/%s", dirname, name);
-
-	return path;
-}
-
-static char *path_glob_first_match(const char *g)
-{
-	glob_t globbuf;
-	char *match = NULL;
-
-	glob(g, 0, NULL, &globbuf);
-
-	if (globbuf.gl_pathc)
-		match = strdup(globbuf.gl_pathv[0]);
-
-	globfree(&globbuf);
-
-	return match;
-}
-
-/*
- * Find and return the full path of the first directory entry that satisfies
- * the match function.
- */
-static char *dir_first_match(const char *dir, int(*match)(const struct dirent *))
-{
-	struct dirent **entries;
-	unsigned int i;
-	int n_entries;
-	char *path;
-
-	n_entries = scandir(dir, &entries, match, alphasort);
-	if (n_entries < 0)
-		return NULL;
-
-	if (n_entries == 0) {
-		free(entries);
-		return NULL;
-	}
-
-	path = path_join(dir, entries[0]->d_name);
-
-	for (i = 0; i < (unsigned int)n_entries; ++i)
-		free(entries[i]);
-
-	free(entries);
-
-	return path;
-}
-
-/* -----------------------------------------------------------------------------
- * Attribute handling
- */
-
-static int attribute_read(const char *path, const char *file, void *buf,
-			  unsigned int len)
-{
-	char *f;
-	int ret;
-	int fd;
-
-	f = path_join(path, file);
-	if (!f)
-		return -ENOMEM;
-
-	fd = open(f, O_RDONLY);
-	free(f);
-	if (fd == -1) {
-		printf("Failed to open attribute %s: %s\n", file,
-		       strerror(errno));
-		return -ENOENT;
-	}
-
-	ret = read(fd, buf, len);
-	close(fd);
-
-	if (ret < 0) {
-		printf("Failed to read attribute %s: %s\n", file,
-		       strerror(errno));
-		return -ENODATA;
-	}
-
-	return len;
-}
-
-static int attribute_read_uint(const char *path, const char *file,
-			       unsigned int *val)
-{
-	/* 4,294,967,295 */
-	char buf[11];
-	char *endptr;
-	int ret;
-
-	ret = attribute_read(path, file, buf, sizeof(buf) - 1);
-	if (ret < 0)
-		return ret;
-
-	buf[ret] = '\0';
-
-	errno = 0;
-
-	/* base 0: Autodetect hex, octal, decimal. */
-	*val = strtoul(buf, &endptr, 0);
-	if (errno)
-		return -errno;
-
-	if (endptr == buf)
-		return -ENODATA;
-
-	return 0;
-}
-
-static char *attribute_read_str(const char *path, const char *file)
-{
-	char buf[1024];
-	char *p;
-	int ret;
-
-	ret = attribute_read(path, file, buf, sizeof(buf) - 1);
-	if (ret < 0)
-		return NULL;
-
-	buf[ret] = '\0';
-
-	p = strrchr(buf, '\n');
-	if (p != buf)
-		*p = '\0';
-
-	return strdup(buf);
-}
-
-/* -----------------------------------------------------------------------------
- * UDC parsing
- */
-
-/*
- * udc_find_video_device - Find the video device node for a UVC function
- * @udc: The UDC name
- * @function: The UVC function name
- *
- * This function finds the video device node corresponding to a UVC function as
- * specified by a @function name and @udc name.
- *
- * The @function parameter specifies the name of the USB function, usually in
- * the form "uvc.%u". If NULL the first function found will be used.
- *
- * The @udc parameter specifies the name of the UDC. If NULL any UDC that
- * contains a function matching the @function name will be used.
- *
- * Return a pointer to a newly allocated string containing the video device node
- * full path if the function is found. Otherwise return NULL. The returned
- * pointer must be freed by the caller with a call to free().
- */
-static char *udc_find_video_device(const char *udc, const char *function)
-{
-	char *vpath;
-	char *video = NULL;
-	glob_t globbuf;
-	unsigned int i;
-
-	asprintf(&vpath, "/sys/class/udc/%s/device/gadget/video4linux/video*",
-		 udc ? udc : "*");
-	if (!vpath)
-		return NULL;
-
-	glob(vpath, 0, NULL, &globbuf);
-	free(vpath);
-
-	for (i = 0; i < globbuf.gl_pathc; ++i) {
-		char *config;
-		bool match;
-
-		/* Match on the first if no search string. */
-		if (!function)
-			break;
-
-		config = attribute_read_str(globbuf.gl_pathv[i],
-					    "function_name");
-		match = strcmp(function, config) == 0;
-
-		free(config);
-
-		if (match)
-			break;
-	}
-
-	if (i < globbuf.gl_pathc) {
-		const char *v = basename(globbuf.gl_pathv[i]);
-
-		video = path_join("/dev", v);
-	}
-
-	globfree(&globbuf);
-
-	return video;
-}
-
-/* ------------------------------------------------------------------------
- * GUIDs and formats
- */
-
-#define UVC_GUID_FORMAT_MJPEG \
-	{ 'M',  'J',  'P',  'G', 0x00, 0x00, 0x10, 0x00, \
-	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
-#define UVC_GUID_FORMAT_YUY2 \
-	{ 'Y',  'U',  'Y',  '2', 0x00, 0x00, 0x10, 0x00, \
-	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
-
-struct uvc_function_format_info {
-	uint8_t guid[16];
-	uint32_t fcc;
-};
-
-static struct uvc_function_format_info uvc_formats[] = {
-	{
-		.guid		= UVC_GUID_FORMAT_YUY2,
-		.fcc		= V4L2_PIX_FMT_YUYV,
-	},
-	{
-		.guid		= UVC_GUID_FORMAT_MJPEG,
-		.fcc		= V4L2_PIX_FMT_MJPEG,
-	},
-};
-
-/* -----------------------------------------------------------------------------
- * Legacy g_webcam support
- */
-
-static const struct uvc_function_config g_webcam_config = {
-	.control = {
-		.intf = {
-			.bInterfaceNumber = 0,
-		},
-	},
-	.streaming = {
-		.intf = {
-			.bInterfaceNumber = 1,
-		},
-		.ep = {
-			.bInterval = 1,
-			.bMaxBurst = 0,
-			.wMaxPacketSize = 1024,
-		},
-		.num_formats = 2,
-		.formats = (struct uvc_function_config_format[]) {
-			{
-				.index = 1,
-				.guid = UVC_GUID_FORMAT_YUY2,
-				.fcc = V4L2_PIX_FMT_YUYV,
-				.num_frames = 2,
-				.frames = (struct uvc_function_config_frame[]) {
-					{
-						.index = 1,
-						.width = 640,
-						.height = 360,
-						.num_intervals = 3,
-						.intervals = (unsigned int[]) {
-							666666,
-							10000000,
-							50000000,
-						},
-					}, {
-						.index = 2,
-						.width = 1280,
-						.height = 720,
-						.num_intervals = 1,
-						.intervals = (unsigned int[]) {
-							50000000,
-						},
-					},
-				},
-			}, {
-				.index = 2,
-				.guid = UVC_GUID_FORMAT_MJPEG,
-				.fcc = V4L2_PIX_FMT_MJPEG,
-				.num_frames = 2,
-				.frames = (struct uvc_function_config_frame[]) {
-					{
-						.index = 1,
-						.width = 640,
-						.height = 360,
-						.num_intervals = 3,
-						.intervals = (unsigned int[]) {
-							666666,
-							10000000,
-							50000000,
-						},
-					}, {
-						.index = 2,
-						.width = 1280,
-						.height = 720,
-						.num_intervals = 1,
-						.intervals = (unsigned int[]) {
-							50000000,
-						},
-					},
-				},
-			},
-		},
-	},
-};
-
-static int parse_legacy_g_webcam(const char *udc,
-				 struct uvc_function_config *fc)
-{
-	void *memdup(const void *src, size_t size)
-	{
-		void *dst;
-
-		dst = malloc(size);
-		if (!dst)
-			return NULL;
-		memcpy(dst, src, size);
-		return dst;
-	}
-
-	unsigned int i, j;
-	size_t size;
-
-	*fc = g_webcam_config;
-
-	/*
-	 * We need to duplicate all sub-structures as the
-	 * configfs_free_uvc_function() function expects them to be dynamically
-	 * allocated.
-	 */
-	size = sizeof *fc->streaming.formats * fc->streaming.num_formats;
-	fc->streaming.formats = memdup(fc->streaming.formats, size);
-
-	for (i = 0; i < fc->streaming.num_formats; ++i) {
-		struct uvc_function_config_format *format =
-			&fc->streaming.formats[i];
-
-		size = sizeof *format->frames * format->num_frames;
-		format->frames = memdup(format->frames, size);
-
-		for (j = 0; j < format->num_frames; ++j) {
-			struct uvc_function_config_frame *frame =
-				&format->frames[j];
-
-			size = sizeof *frame->intervals * frame->num_intervals;
-			frame->intervals = memdup(frame->intervals, size);
-		}
-	}
-
-	fc->video = udc_find_video_device(udc, NULL);
-
-	return fc->video ? 0 : -ENODEV;
-}
-
-/* -----------------------------------------------------------------------------
- * ConfigFS support
- */
-
-/*
- * configfs_find_uvc_function - Find the ConfigFS full path for a UVC function
- * @function: The UVC function name
- *
- * Return a pointer to a newly allocated string containing the full ConfigFS
- * path to the function if the function is found. Otherwise return NULL. The
- * returned pointer must be freed by the caller with a call to free().
- */
-static char *configfs_find_uvc_function(const char *function)
-{
-	const char *target = function ? function : "*";
-	const char *root;
-	char *func_path;
-	char *path;
-
-	/*
-	 * The function description can be provided as a path from the
-	 * usb_gadget root "g1/functions/uvc.0", or if there is no ambiguity
-	 * over the gadget name, a shortcut "uvc.0" can be provided.
-	 */
-	if (!strchr(target, '/'))
-		root = "/sys/kernel/config/usb_gadget/*/functions";
-	else
-		root = "/sys/kernel/config/usb_gadget";
-
-	path = path_join(root, target);
-
-	func_path = path_glob_first_match(path);
-	free(path);
-
-	return func_path;
-}
-
-/*
- * configfs_free_uvc_function - Free a uvc_function_config object
- * @fc: The uvc_function_config to be freed
- *
- * Free the given @fc function previously allocated by a call to
- * configfs_parse_uvc_function().
- */
-void configfs_free_uvc_function(struct uvc_function_config *fc)
-{
-	unsigned int i, j;
-
-	free(fc->udc);
-	free(fc->video);
-
-	for (i = 0; i < fc->streaming.num_formats; ++i) {
-		struct uvc_function_config_format *format =
-			&fc->streaming.formats[i];
-
-		for (j = 0; j < format->num_frames; ++j) {
-			struct uvc_function_config_frame *frame =
-				&format->frames[j];
-
-			free(frame->intervals);
-		}
-
-		free(format->frames);
-	}
-
-	free(fc->streaming.formats);
-	free(fc);
-}
-
-#define configfs_parse_child(parent, child, cfg, parse)			\
-({									\
-	char *__path;							\
-	int __ret;							\
-									\
-	__path = path_join((parent), (child));				\
-	if (__path) {							\
-		__ret = parse(__path, (cfg));				\
-		free(__path);						\
-	} else {							\
-		__ret = -ENOMEM;					\
-	}								\
-									\
-	__ret;								\
-})
-
-static int configfs_parse_interface(const char *path,
-				    struct uvc_function_config_interface *cfg)
-{
-	int ret;
-
-	ret = attribute_read_uint(path, "bInterfaceNumber",
-				  &cfg->bInterfaceNumber);
-
-	return ret;
-}
-
-static int configfs_parse_control(const char *path,
-				  struct uvc_function_config_control *cfg)
-{
-	int ret;
-
-	ret = configfs_parse_interface(path, &cfg->intf);
-
-	return ret;
-}
-
-static int configfs_parse_streaming_frame(const char *path,
-			struct uvc_function_config_frame *frame)
-{
-	char *intervals;
-	char *p;
-	int ret = 0;
-
-	ret = ret ? : attribute_read_uint(path, "bFrameIndex", &frame->index);
-	ret = ret ? : attribute_read_uint(path, "wWidth", &frame->width);
-	ret = ret ? : attribute_read_uint(path, "wHeight", &frame->height);
-	if (ret)
-		return ret;
-
-	intervals = attribute_read_str(path, "dwFrameInterval");
-	if (!intervals)
-		return -EINVAL;
-
-	for (p = intervals; *p; ) {
-		unsigned int interval;
-		unsigned int *mem;
-		char *endp;
-		size_t size;
-
-		interval = strtoul(p, &endp, 10);
-		if (*endp != '\0' && *endp != '\n') {
-			ret = -EINVAL;
-			break;
-		}
-
-		p = *endp ? endp + 1 : endp;
-
-		size = sizeof *frame->intervals * (frame->num_intervals + 1);
-		mem = realloc(frame->intervals, size);
-		if (!mem) {
-			ret = -ENOMEM;
-			break;
-		}
-
-		frame->intervals = mem;
-		frame->intervals[frame->num_intervals++] = interval;
-	}
-
-	free(intervals);
-
-	return ret;
-}
-
-static int configfs_parse_streaming_format(const char *path,
-			struct uvc_function_config_format *format)
-{
-	int frame_filter(const struct dirent *ent)
-	{
-		/* Accept all directories but "." and "..". */
-		if (ent->d_type != DT_DIR)
-			return 0;
-		if (!strcmp(ent->d_name, "."))
-			return 0;
-		if (!strcmp(ent->d_name, ".."))
-			return 0;
-		return 1;
-	}
-
-	int frame_compare(const void *a, const void *b)
-	{
-		const struct uvc_function_config_frame *fa = a;
-		const struct uvc_function_config_frame *fb = b;
-
-		if (fa->index < fb->index)
-			return -1;
-		else if (fa->index == fb->index)
-			return 0;
-		else
-			return 1;
-	}
-
-	struct dirent **entries;
-	unsigned int i;
-	int n_entries;
-	int ret;
-
-	ret = attribute_read_uint(path, "bFormatIndex", &format->index);
-	if (ret < 0)
-		return ret;
-
-	ret = attribute_read(path, "guidFormat", format->guid,
-			     sizeof(format->guid));
-	if (ret < 0)
-		return ret;
-	if (ret != 16)
-		return -EINVAL;
-
-	for (i = 0; i < ARRAY_SIZE(uvc_formats); ++i) {
-		if (!memcmp(uvc_formats[i].guid, format->guid, 16)) {
-			format->fcc = uvc_formats[i].fcc;
-			break;
-		}
-	}
-
-	/* Find all entries corresponding to a frame and parse them. */
-	n_entries = scandir(path, &entries, frame_filter, alphasort);
-	if (n_entries < 0)
-		return -errno;
-
-	if (n_entries == 0) {
-		free(entries);
-		return -EINVAL;
-	}
-
-	format->num_frames = n_entries;
-	format->frames = calloc(sizeof *format->frames, format->num_frames);
-	if (!format->frames)
-		return -ENOMEM;
-
-	for (i = 0; i < (unsigned int)n_entries; ++i) {
-		char *frame;
-
-		frame = path_join(path, entries[i]->d_name);
-		if (!frame) {
-			ret = -ENOMEM;
-			goto done;
-		}
-
-		ret = configfs_parse_streaming_frame(frame, &format->frames[i]);
-		free(frame);
-		if (ret < 0)
-			goto done;
-	}
-
-	/* Sort the frames by index. */
-	qsort(format->frames, format->num_frames, sizeof *format->frames,
-	      frame_compare);
-
-done:
-	for (i = 0; i < (unsigned int)n_entries; ++i)
-		free(entries[i]);
-	free(entries);
-
-	return ret;
-}
-
-static int configfs_parse_streaming_header(const char *path,
-			struct uvc_function_config_streaming *cfg)
-{
-	int format_filter(const struct dirent *ent)
-	{
-		char *path;
-		bool valid;
-
-		/*
-		 * Accept all links that point to a directory containing a
-		 * "bFormatIndex" file.
-		 */
-		if (ent->d_type != DT_LNK)
-			return 0;
-
-		path = path_join(ent->d_name, "bFormatIndex");
-		if (!path)
-			return 0;
-
-		valid = access(path, R_OK);
-		free(path);
-		return valid;
-	}
-
-	int format_compare(const void *a, const void *b)
-	{
-		const struct uvc_function_config_format *fa = a;
-		const struct uvc_function_config_format *fb = b;
-
-		if (fa->index < fb->index)
-			return -1;
-		else if (fa->index == fb->index)
-			return 0;
-		else
-			return 1;
-	}
-
-	struct dirent **entries;
-	unsigned int i;
-	int n_entries;
-	int ret;
-
-	/* Find all entries corresponding to a format and parse them. */
-	n_entries = scandir(path, &entries, format_filter, alphasort);
-	if (n_entries < 0)
-		return -errno;
-
-	if (n_entries == 0) {
-		free(entries);
-		return -EINVAL;
-	}
-
-	cfg->num_formats = n_entries;
-	cfg->formats = calloc(sizeof *cfg->formats, cfg->num_formats);
-	if (!cfg->formats)
-		return -ENOMEM;
-
-	for (i = 0; i < (unsigned int)n_entries; ++i) {
-		char *format;
-
-		format = path_join(path, entries[i]->d_name);
-		if (!format) {
-			ret = -ENOMEM;
-			goto done;
-		}
-
-		ret = configfs_parse_streaming_format(format, &cfg->formats[i]);
-		free(format);
-		if (ret < 0)
-			goto done;
-	}
-
-	/* Sort the formats by index. */
-	qsort(cfg->formats, cfg->num_formats, sizeof *cfg->formats,
-	      format_compare);
-
-done:
-	for (i = 0; i < (unsigned int)n_entries; ++i)
-		free(entries[i]);
-	free(entries);
-
-	return ret;
-}
-
-static int configfs_parse_streaming(const char *path,
-				    struct uvc_function_config_streaming *cfg)
-{
-	int link_filter(const struct dirent *ent)
-	{
-		/* Accept all links. */
-		return ent->d_type == DT_LNK;
-	}
-
-	char *header;
-	char *class;
-	int ret;
-
-	ret = configfs_parse_interface(path, &cfg->intf);
-	if (ret < 0)
-		return ret;
-
-	/*
-	 * Handle the high-speed class descriptors only for now. Find the first
-	 * link to the class descriptors.
-	 */
-	class = path_join(path, "class/hs");
-	if (!class)
-		return -ENOMEM;
-
-	header = dir_first_match(class, link_filter);
-	free(class);
-	if (!header)
-		return -EINVAL;
-
-	ret = configfs_parse_streaming_header(header, cfg);
-	free(header);
-	return ret;
-}
-
-static int configfs_parse_uvc(const char *fpath,
-			      struct uvc_function_config *fc)
-{
-	int ret = 0;
-
-	ret = ret ? : configfs_parse_child(fpath, "control", &fc->control,
-					   configfs_parse_control);
-	ret = ret ? : configfs_parse_child(fpath, "streaming", &fc->streaming,
-					   configfs_parse_streaming);
-
-	/*
-	 * These parameters should be part of the streaming interface in
-	 * ConfigFS, but for legacy reasons they are located directly in the
-	 * function directory.
-	 */
-	ret = ret ? : attribute_read_uint(fpath, "streaming_interval",
-					  &fc->streaming.ep.bInterval);
-	ret = ret ? : attribute_read_uint(fpath, "streaming_maxburst",
-					  &fc->streaming.ep.bMaxBurst);
-	ret = ret ? : attribute_read_uint(fpath, "streaming_maxpacket",
-					  &fc->streaming.ep.wMaxPacketSize);
-
-	return ret;
-}
-
-/*
- * configfs_parse_uvc_function - Parse a UVC function configuration in ConfigFS
- * @function: The function name
- *
- * This function locates and parse the configuration of a UVC function in
- * ConfigFS as specified by the @function name argument. The function name can
- * be fully qualified with a gadget name (e.g. "g%u/functions/uvc.%u"), or as a
- * shortcut can be an unqualified function name (e.g. "uvc.%u"). When the
- * function name is unqualified, the first function matching the name in any
- * UDC will be returned.
- *
- * Return a pointer to a newly allocated UVC function configuration structure
- * that contains configuration parameters for the function, if the function is
- * found. Otherwise return NULL. The returned pointer must be freed by the
- * caller with a call to free().
- */
-struct uvc_function_config *configfs_parse_uvc_function(const char *function)
-{
-	struct uvc_function_config *fc;
-	char *fpath;
-	int ret = 0;
-
-	fc = malloc(sizeof *fc);
-	if (fc == NULL)
-		return NULL;
-
-	memset(fc, 0, sizeof *fc);
-
-	/* Find the function in ConfigFS. */
-	fpath = configfs_find_uvc_function(function);
-	if (!fpath) {
-		/*
-		 * If the function can't be found attempt legacy parsing to
-		 * support the g_webcam gadget. The function parameter contains
-		 * a UDC name in that case.
-		 */
-		ret = parse_legacy_g_webcam(function, fc);
-		if (ret) {
-			configfs_free_uvc_function(fc);
-			fc = NULL;
-		}
-
-		return fc;
-	}
-
-	/*
-	 * Parse the function configuration. Remove the gadget name qualifier
-	 * from the function name, if any.
-	 */
-	if (function)
-		function = basename(function);
-
-	fc->udc = attribute_read_str(fpath, "../../UDC");
-	fc->video = udc_find_video_device(fc->udc, function);
-	if (!fc->video) {
-		ret = -ENODEV;
-		goto done;
-	}
-
-	ret = configfs_parse_uvc(fpath, fc);
-
-done:
-	if (ret) {
-		configfs_free_uvc_function(fc);
-		fc = NULL;
-	}
-
-	free(fpath);
-
-	return fc;
-}