diff options
Diffstat (limited to 'configfs.c')
| -rw-r--r-- | configfs.c | 846 |
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; -} |