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authorKieran Bingham <kieran.bingham@ideasonboard.com>2018-07-31 17:10:20 +0100
committerLaurent Pinchart <laurent.pinchart@ideasonboard.com>2018-07-31 23:50:02 +0300
commited050498a2d2aa1e00b3cb4bbeb0d72a96cc9009 (patch)
tree3a9b91d2c21eb96e5da6729c70b765b39d9dbc43 /lib
parent6a6e9d22b338bb2c290b7c7fd0ae434ad13232d9 (diff)
lib: configfs: Detect configfs mount point
Parse /proc/mounts to identify the correct mount location of the ConfigFS filesystem. Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Diffstat (limited to 'lib')
-rw-r--r--lib/configfs.c58
1 files changed, 54 insertions, 4 deletions
diff --git a/lib/configfs.c b/lib/configfs.c
index 0a8d8e5..56bff01 100644
--- a/lib/configfs.c
+++ b/lib/configfs.c
@@ -399,6 +399,46 @@ static int parse_legacy_g_webcam(const char *udc,
*/
/*
+ * configfs_mount_point - Identify the ConfigFS mount location
+ *
+ * Return a pointer to a newly allocated string containing the fully qualified
+ * path to the ConfigFS mount point if located. Returns NULL if the ConfigFS
+ * mount point can not be identified.
+ */
+static char *configfs_mount_point(void)
+{
+ FILE *mounts;
+ char *line = NULL;
+ char *path = NULL;
+ size_t len = 0;
+
+ mounts = fopen("/proc/mounts", "r");
+ if (mounts == NULL)
+ return NULL;
+
+ while (getline(&line, &len, mounts) != -1) {
+ if (strstr(line, "configfs")) {
+ char *saveptr;
+ char *token;
+
+ /* Obtain the second token. */
+ token = strtok_r(line, " ", &saveptr);
+ token = strtok_r(NULL, " ", &saveptr);
+
+ if (token)
+ path = strdup(token);
+
+ break;
+ }
+ }
+
+ free(line);
+ fclose(mounts);
+
+ return path;
+}
+
+/*
* configfs_find_uvc_function - Find the ConfigFS full path for a UVC function
* @function: The UVC function name
*
@@ -409,9 +449,15 @@ static int parse_legacy_g_webcam(const char *udc,
static char *configfs_find_uvc_function(const char *function)
{
const char *target = function ? function : "*";
- const char *root;
+ const char *format;
+ char *configfs;
char *func_path;
char *path;
+ int ret;
+
+ configfs = configfs_mount_point();
+ if (!configfs)
+ printf("Failed to locate configfs mount point, using default\n");
/*
* The function description can be provided as a path from the
@@ -419,11 +465,15 @@ static char *configfs_find_uvc_function(const char *function)
* over the gadget name, a shortcut "uvc.0" can be provided.
*/
if (!strchr(target, '/'))
- root = "/sys/kernel/config/usb_gadget/*/functions";
+ format = "%s/usb_gadget/*/functions/%s";
else
- root = "/sys/kernel/config/usb_gadget";
+ format = "%s/usb_gadget/%s";
- path = path_join(root, target);
+ ret = asprintf(&path, format, configfs ? configfs : "/sys/kernel/config",
+ target);
+ free(configfs);
+ if (!ret)
+ return NULL;
func_path = path_glob_first_match(path);
free(path);