[media] uvcvideo: Add debugfs support

Create a debugfs entry per UVC stream. This will be used to export
stream statistics.

Signed-off-by: Alexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
[mchehab@redhat.com: add incude <linux/module.h> to avoid compilation breakage]
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 77 insertions, 0 deletions

diff --git a/drivers/media/video/uvc/uvc_debugfs.c b/drivers/media/video/uvc/uvc_debugfs.c
new file mode 100644
index 000000000000..39fd43b3e1d2
--- /dev/null
+++ b/drivers/media/video/uvc/uvc_debugfs.c
@@ -0,0 +1,77 @@
+/*
+ *      uvc_debugfs.c --  USB Video Class driver - Debugging support
+ *
+ *      Copyright (C) 2011
+ *          Laurent Pinchart (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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+
+#include "uvcvideo.h"
+
+/* -----------------------------------------------------------------------------
+ * Global and stream initialization/cleanup
+ */
+
+static struct dentry *uvc_debugfs_root_dir;
+
+int uvc_debugfs_init_stream(struct uvc_streaming *stream)
+{
+	struct usb_device *udev = stream->dev->udev;
+	struct dentry *dent;
+	char dir_name[32];
+
+	if (uvc_debugfs_root_dir == NULL)
+		return -ENODEV;
+
+	sprintf(dir_name, "%u-%u", udev->bus->busnum, udev->devnum);
+
+	dent = debugfs_create_dir(dir_name, uvc_debugfs_root_dir);
+	if (IS_ERR_OR_NULL(dent)) {
+		uvc_printk(KERN_INFO, "Unable to create debugfs %s directory.\n",
+			   dir_name);
+		return -ENODEV;
+	}
+
+	stream->debugfs_dir = dent;
+
+	return 0;
+}
+
+void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream)
+{
+	if (stream->debugfs_dir == NULL)
+		return;
+
+	debugfs_remove_recursive(stream->debugfs_dir);
+	stream->debugfs_dir = NULL;
+}
+
+int uvc_debugfs_init(void)
+{
+	struct dentry *dir;
+
+	dir = debugfs_create_dir("uvcvideo", usb_debug_root);
+	if (IS_ERR_OR_NULL(dir)) {
+		uvc_printk(KERN_INFO, "Unable to create debugfs directory\n");
+		return -ENODATA;
+	}
+
+	uvc_debugfs_root_dir = dir;
+	return 0;
+}
+
+void uvc_debugfs_cleanup(void)
+{
+	if (uvc_debugfs_root_dir != NULL)
+		debugfs_remove_recursive(uvc_debugfs_root_dir);
+}