1 files changed, 105 insertions, 0 deletions
diff --git a/drivers/media/usb/uvc/uvc_debugfs.c b/drivers/media/usb/uvc/uvc_debugfs.c
new file mode 100644
index 000000000..1a1258d4f
--- /dev/null
+++ b/drivers/media/usb/uvc/uvc_debugfs.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *      uvc_debugfs.c --  USB Video Class driver - Debugging support
+ *
+ *      Copyright (C) 2011
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ */
+
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+
+#include "uvcvideo.h"
+
+/* -----------------------------------------------------------------------------
+ * Statistics
+ */
+
+#define UVC_DEBUGFS_BUF_SIZE	1024
+
+struct uvc_debugfs_buffer {
+	size_t count;
+	char data[UVC_DEBUGFS_BUF_SIZE];
+};
+
+static int uvc_debugfs_stats_open(struct inode *inode, struct file *file)
+{
+	struct uvc_streaming *stream = inode->i_private;
+	struct uvc_debugfs_buffer *buf;
+
+	buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	buf->count = uvc_video_stats_dump(stream, buf->data, sizeof(buf->data));
+
+	file->private_data = buf;
+	return 0;
+}
+
+static ssize_t uvc_debugfs_stats_read(struct file *file, char __user *user_buf,
+				      size_t nbytes, loff_t *ppos)
+{
+	struct uvc_debugfs_buffer *buf = file->private_data;
+
+	return simple_read_from_buffer(user_buf, nbytes, ppos, buf->data,
+				       buf->count);
+}
+
+static int uvc_debugfs_stats_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	file->private_data = NULL;
+
+	return 0;
+}
+
+static const struct file_operations uvc_debugfs_stats_fops = {
+	.owner = THIS_MODULE,
+	.open = uvc_debugfs_stats_open,
+	.llseek = no_llseek,
+	.read = uvc_debugfs_stats_read,
+	.release = uvc_debugfs_stats_release,
+};
+
+/* -----------------------------------------------------------------------------
+ * Global and stream initialization/cleanup
+ */
+
+static struct dentry *uvc_debugfs_root_dir;
+
+void uvc_debugfs_init_stream(struct uvc_streaming *stream)
+{
+	struct usb_device *udev = stream->dev->udev;
+	char dir_name[33];
+
+	if (uvc_debugfs_root_dir == NULL)
+		return;
+
+	snprintf(dir_name, sizeof(dir_name), "%u-%u-%u", udev->bus->busnum,
+		 udev->devnum, stream->intfnum);
+
+	stream->debugfs_dir = debugfs_create_dir(dir_name,
+						 uvc_debugfs_root_dir);
+
+	debugfs_create_file("stats", 0444, stream->debugfs_dir, stream,
+			    &uvc_debugfs_stats_fops);
+}
+
+void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream)
+{
+	debugfs_remove_recursive(stream->debugfs_dir);
+	stream->debugfs_dir = NULL;
+}
+
+void uvc_debugfs_init(void)
+{
+	uvc_debugfs_root_dir = debugfs_create_dir("uvcvideo", usb_debug_root);
+}
+
+void uvc_debugfs_cleanup(void)
+{
+	debugfs_remove_recursive(uvc_debugfs_root_dir);
+}