1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * uvc_debugfs.c -- USB Video Class driver - Debugging support
4 *
5 * Copyright (C) 2011
6 * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
7 */
8
9 #include <linux/module.h>
10 #include <linux/debugfs.h>
11 #include <linux/slab.h>
12 #include <linux/usb.h>
13
14 #include "uvcvideo.h"
15
16 /* -----------------------------------------------------------------------------
17 * Statistics
18 */
19
20 #define UVC_DEBUGFS_BUF_SIZE 1024
21
22 struct uvc_debugfs_buffer {
23 size_t count;
24 char data[UVC_DEBUGFS_BUF_SIZE];
25 };
26
uvc_debugfs_stats_open(struct inode * inode,struct file * file)27 static int uvc_debugfs_stats_open(struct inode *inode, struct file *file)
28 {
29 struct uvc_streaming *stream = inode->i_private;
30 struct uvc_debugfs_buffer *buf;
31
32 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
33 if (buf == NULL)
34 return -ENOMEM;
35
36 buf->count = uvc_video_stats_dump(stream, buf->data, sizeof(buf->data));
37
38 file->private_data = buf;
39 return 0;
40 }
41
uvc_debugfs_stats_read(struct file * file,char __user * user_buf,size_t nbytes,loff_t * ppos)42 static ssize_t uvc_debugfs_stats_read(struct file *file, char __user *user_buf,
43 size_t nbytes, loff_t *ppos)
44 {
45 struct uvc_debugfs_buffer *buf = file->private_data;
46
47 return simple_read_from_buffer(user_buf, nbytes, ppos, buf->data,
48 buf->count);
49 }
50
uvc_debugfs_stats_release(struct inode * inode,struct file * file)51 static int uvc_debugfs_stats_release(struct inode *inode, struct file *file)
52 {
53 kfree(file->private_data);
54 file->private_data = NULL;
55
56 return 0;
57 }
58
59 static const struct file_operations uvc_debugfs_stats_fops = {
60 .owner = THIS_MODULE,
61 .open = uvc_debugfs_stats_open,
62 .read = uvc_debugfs_stats_read,
63 .release = uvc_debugfs_stats_release,
64 };
65
66 /* -----------------------------------------------------------------------------
67 * Global and stream initialization/cleanup
68 */
69
70 static struct dentry *uvc_debugfs_root_dir;
71
uvc_debugfs_init_stream(struct uvc_streaming * stream)72 void uvc_debugfs_init_stream(struct uvc_streaming *stream)
73 {
74 struct usb_device *udev = stream->dev->udev;
75 char dir_name[33];
76
77 if (uvc_debugfs_root_dir == NULL)
78 return;
79
80 snprintf(dir_name, sizeof(dir_name), "%u-%u-%u", udev->bus->busnum,
81 udev->devnum, stream->intfnum);
82
83 stream->debugfs_dir = debugfs_create_dir(dir_name,
84 uvc_debugfs_root_dir);
85
86 debugfs_create_file("stats", 0444, stream->debugfs_dir, stream,
87 &uvc_debugfs_stats_fops);
88 }
89
uvc_debugfs_cleanup_stream(struct uvc_streaming * stream)90 void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream)
91 {
92 debugfs_remove_recursive(stream->debugfs_dir);
93 stream->debugfs_dir = NULL;
94 }
95
uvc_debugfs_init(void)96 void uvc_debugfs_init(void)
97 {
98 uvc_debugfs_root_dir = debugfs_create_dir("uvcvideo", usb_debug_root);
99 }
100
uvc_debugfs_cleanup(void)101 void uvc_debugfs_cleanup(void)
102 {
103 debugfs_remove_recursive(uvc_debugfs_root_dir);
104 }
105