105 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * uvc_debugfs.c -- USB Video Class driver - Debugging support4 *5 * Copyright (C) 20116 * 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 * Statistics18 */19 20#define UVC_DEBUGFS_BUF_SIZE 102421 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 .read = uvc_debugfs_stats_read,63 .release = uvc_debugfs_stats_release,64};65 66/* -----------------------------------------------------------------------------67 * Global and stream initialization/cleanup68 */69 70static struct dentry *uvc_debugfs_root_dir;71 72void 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 90void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream)91{92 debugfs_remove_recursive(stream->debugfs_dir);93 stream->debugfs_dir = NULL;94}95 96void uvc_debugfs_init(void)97{98 uvc_debugfs_root_dir = debugfs_create_dir("uvcvideo", usb_debug_root);99}100 101void uvc_debugfs_cleanup(void)102{103 debugfs_remove_recursive(uvc_debugfs_root_dir);104}105