aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/media/usb/uvc/uvc_debugfs.c
blob: 14561a5abb793df434e40bbaa29a5db7d43e5e9c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
/*
 *      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"

/* -----------------------------------------------------------------------------
 * 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;

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;

	dent = debugfs_create_file("stats", 0444, stream->debugfs_dir,
				   stream, &uvc_debugfs_stats_fops);
	if (IS_ERR_OR_NULL(dent)) {
		uvc_printk(KERN_INFO, "Unable to create debugfs stats file.\n");
		uvc_debugfs_cleanup_stream(stream);
		return -ENODEV;
	}

	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);
}