2 * uvc_debugfs.c -- USB Video Class driver - Debugging support
5 * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
14 #include <linux/module.h>
15 #include <linux/debugfs.h>
16 #include <linux/slab.h>
17 #include <linux/usb.h>
21 /* -----------------------------------------------------------------------------
25 #define UVC_DEBUGFS_BUF_SIZE 1024
27 struct uvc_debugfs_buffer {
29 char data[UVC_DEBUGFS_BUF_SIZE];
32 static int uvc_debugfs_stats_open(struct inode *inode, struct file *file)
34 struct uvc_streaming *stream = inode->i_private;
35 struct uvc_debugfs_buffer *buf;
37 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
41 buf->count = uvc_video_stats_dump(stream, buf->data, sizeof(buf->data));
43 file->private_data = buf;
47 static ssize_t uvc_debugfs_stats_read(struct file *file, char __user *user_buf,
48 size_t nbytes, loff_t *ppos)
50 struct uvc_debugfs_buffer *buf = file->private_data;
52 return simple_read_from_buffer(user_buf, nbytes, ppos, buf->data,
56 static int uvc_debugfs_stats_release(struct inode *inode, struct file *file)
58 kfree(file->private_data);
59 file->private_data = NULL;
64 static const struct file_operations uvc_debugfs_stats_fops = {
66 .open = uvc_debugfs_stats_open,
68 .read = uvc_debugfs_stats_read,
69 .release = uvc_debugfs_stats_release,
72 /* -----------------------------------------------------------------------------
73 * Global and stream initialization/cleanup
76 static struct dentry *uvc_debugfs_root_dir;
78 int uvc_debugfs_init_stream(struct uvc_streaming *stream)
80 struct usb_device *udev = stream->dev->udev;
84 if (uvc_debugfs_root_dir == NULL)
87 sprintf(dir_name, "%u-%u", udev->bus->busnum, udev->devnum);
89 dent = debugfs_create_dir(dir_name, uvc_debugfs_root_dir);
90 if (IS_ERR_OR_NULL(dent)) {
91 uvc_printk(KERN_INFO, "Unable to create debugfs %s "
92 "directory.\n", dir_name);
96 stream->debugfs_dir = dent;
98 dent = debugfs_create_file("stats", 0444, stream->debugfs_dir,
99 stream, &uvc_debugfs_stats_fops);
100 if (IS_ERR_OR_NULL(dent)) {
101 uvc_printk(KERN_INFO, "Unable to create debugfs stats file.\n");
102 uvc_debugfs_cleanup_stream(stream);
109 void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream)
111 if (stream->debugfs_dir == NULL)
114 debugfs_remove_recursive(stream->debugfs_dir);
115 stream->debugfs_dir = NULL;
118 int uvc_debugfs_init(void)
122 dir = debugfs_create_dir("uvcvideo", usb_debug_root);
123 if (IS_ERR_OR_NULL(dir)) {
124 uvc_printk(KERN_INFO, "Unable to create debugfs directory\n");
128 uvc_debugfs_root_dir = dir;
132 void uvc_debugfs_cleanup(void)
134 if (uvc_debugfs_root_dir != NULL)
135 debugfs_remove_recursive(uvc_debugfs_root_dir);