1/*
2 *      uvc_debugfs.c --  USB Video Class driver - Debugging support
3 *
4 *      Copyright (C) 2011
5 *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
6 *
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.
11 *
12 */
13
14#include <linux/module.h>
15#include <linux/debugfs.h>
16#include <linux/slab.h>
17#include <linux/usb.h>
18
19#include "uvcvideo.h"
20
21/* -----------------------------------------------------------------------------
22 * Statistics
23 */
24
25#define UVC_DEBUGFS_BUF_SIZE	1024
26
27struct uvc_debugfs_buffer {
28	size_t count;
29	char data[UVC_DEBUGFS_BUF_SIZE];
30};
31
32static int uvc_debugfs_stats_open(struct inode *inode, struct file *file)
33{
34	struct uvc_streaming *stream = inode->i_private;
35	struct uvc_debugfs_buffer *buf;
36
37	buf = kmalloc(sizeof(*buf), GFP_KERNEL);
38	if (buf == NULL)
39		return -ENOMEM;
40
41	buf->count = uvc_video_stats_dump(stream, buf->data, sizeof(buf->data));
42
43	file->private_data = buf;
44	return 0;
45}
46
47static ssize_t uvc_debugfs_stats_read(struct file *file, char __user *user_buf,
48				      size_t nbytes, loff_t *ppos)
49{
50	struct uvc_debugfs_buffer *buf = file->private_data;
51
52	return simple_read_from_buffer(user_buf, nbytes, ppos, buf->data,
53				       buf->count);
54}
55
56static int uvc_debugfs_stats_release(struct inode *inode, struct file *file)
57{
58	kfree(file->private_data);
59	file->private_data = NULL;
60
61	return 0;
62}
63
64static const struct file_operations uvc_debugfs_stats_fops = {
65	.owner = THIS_MODULE,
66	.open = uvc_debugfs_stats_open,
67	.llseek = no_llseek,
68	.read = uvc_debugfs_stats_read,
69	.release = uvc_debugfs_stats_release,
70};
71
72/* -----------------------------------------------------------------------------
73 * Global and stream initialization/cleanup
74 */
75
76static struct dentry *uvc_debugfs_root_dir;
77
78int uvc_debugfs_init_stream(struct uvc_streaming *stream)
79{
80	struct usb_device *udev = stream->dev->udev;
81	struct dentry *dent;
82	char dir_name[32];
83
84	if (uvc_debugfs_root_dir == NULL)
85		return -ENODEV;
86
87	sprintf(dir_name, "%u-%u", udev->bus->busnum, udev->devnum);
88
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);
93		return -ENODEV;
94	}
95
96	stream->debugfs_dir = dent;
97
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);
103		return -ENODEV;
104	}
105
106	return 0;
107}
108
109void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream)
110{
111	if (stream->debugfs_dir == NULL)
112		return;
113
114	debugfs_remove_recursive(stream->debugfs_dir);
115	stream->debugfs_dir = NULL;
116}
117
118int uvc_debugfs_init(void)
119{
120	struct dentry *dir;
121
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");
125		return -ENODATA;
126	}
127
128	uvc_debugfs_root_dir = dir;
129	return 0;
130}
131
132void uvc_debugfs_cleanup(void)
133{
134	if (uvc_debugfs_root_dir != NULL)
135		debugfs_remove_recursive(uvc_debugfs_root_dir);
136}
137