linux/drivers/media/usb/uvc/uvc_debugfs.c
Jaejoong Kim 39dc3aaeec [media] uvcvideo: Change result code of debugfs_init to void
The device driver should keep going even if debugfs initialization fails.
So, change the return type to void.

Signed-off-by: Jaejoong Kim <climbbb.kim@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-01-31 10:56:48 -02:00

134 lines
3.2 KiB
C

/*
* 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;
void 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;
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;
}
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;
}
}
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;
}
void 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;
}
uvc_debugfs_root_dir = dir;
}
void uvc_debugfs_cleanup(void)
{
if (uvc_debugfs_root_dir != NULL)
debugfs_remove_recursive(uvc_debugfs_root_dir);
}