Merge tag 'drivers-5.10-2020-10-12' of git://git.kernel.dk/linux-block
[linux-2.6-block.git] / drivers / media / usb / uvc / uvc_debugfs.c
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2874c5fd 1// SPDX-License-Identifier: GPL-2.0-or-later
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2/*
3 * uvc_debugfs.c -- USB Video Class driver - Debugging support
4 *
5 * Copyright (C) 2011
6 * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
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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
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16/* -----------------------------------------------------------------------------
17 * Statistics
18 */
19
20#define UVC_DEBUGFS_BUF_SIZE 1024
21
22struct uvc_debugfs_buffer {
23 size_t count;
24 char data[UVC_DEBUGFS_BUF_SIZE];
25};
26
27static 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
42static 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
51static 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
59static const struct file_operations uvc_debugfs_stats_fops = {
60 .owner = THIS_MODULE,
61 .open = uvc_debugfs_stats_open,
62 .llseek = no_llseek,
63 .read = uvc_debugfs_stats_read,
64 .release = uvc_debugfs_stats_release,
65};
66
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67/* -----------------------------------------------------------------------------
68 * Global and stream initialization/cleanup
69 */
70
71static struct dentry *uvc_debugfs_root_dir;
72
39dc3aae 73void uvc_debugfs_init_stream(struct uvc_streaming *stream)
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74{
75 struct usb_device *udev = stream->dev->udev;
675e2f20 76 char dir_name[33];
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77
78 if (uvc_debugfs_root_dir == NULL)
39dc3aae 79 return;
edbaa398 80
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81 snprintf(dir_name, sizeof(dir_name), "%u-%u-%u", udev->bus->busnum,
82 udev->devnum, stream->intfnum);
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84 stream->debugfs_dir = debugfs_create_dir(dir_name,
85 uvc_debugfs_root_dir);
edbaa398 86
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87 debugfs_create_file("stats", 0444, stream->debugfs_dir, stream,
88 &uvc_debugfs_stats_fops);
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89}
90
91void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream)
92{
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93 debugfs_remove_recursive(stream->debugfs_dir);
94 stream->debugfs_dir = NULL;
95}
96
39dc3aae 97void uvc_debugfs_init(void)
edbaa398 98{
54ef0b39 99 uvc_debugfs_root_dir = debugfs_create_dir("uvcvideo", usb_debug_root);
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100}
101
102void uvc_debugfs_cleanup(void)
103{
829682b3 104 debugfs_remove_recursive(uvc_debugfs_root_dir);
edbaa398 105}