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
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* Copyright (C) 2019, Google Inc.
*
* device_enumerator_sysfs.cpp - sysfs-based device enumerator
*/
#include "device_enumerator_sysfs.h"
#include <dirent.h>
#include <fcntl.h>
#include <fstream>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "log.h"
namespace libcamera {
LOG_DECLARE_CATEGORY(DeviceEnumerator)
int DeviceEnumeratorSysfs::init()
{
return 0;
}
int DeviceEnumeratorSysfs::enumerate()
{
struct dirent *ent;
DIR *dir;
static const char * const sysfs_dirs[] = {
"/sys/subsystem/media/devices",
"/sys/bus/media/devices",
"/sys/class/media/devices",
};
for (const char *dirname : sysfs_dirs) {
dir = opendir(dirname);
if (dir)
break;
}
if (!dir) {
LOG(DeviceEnumerator, Error)
<< "No valid sysfs media device directory";
return -ENODEV;
}
while ((ent = readdir(dir)) != nullptr) {
if (strncmp(ent->d_name, "media", 5))
continue;
char *end;
unsigned int idx = strtoul(ent->d_name + 5, &end, 10);
if (*end != '\0')
continue;
std::string devnode = "/dev/media" + std::to_string(idx);
/* Verify that the device node exists. */
struct stat devstat;
if (stat(devnode.c_str(), &devstat) < 0) {
LOG(DeviceEnumerator, Warning)
<< "Device node /dev/media" << idx
<< " should exist but doesn't";
continue;
}
addDevice(devnode);
}
closedir(dir);
return 0;
}
std::string DeviceEnumeratorSysfs::lookupDeviceNode(int major, int minor)
{
std::string deviceNode;
std::string line;
std::ifstream ueventFile;
ueventFile.open("/sys/dev/char/" + std::to_string(major) + ":" +
std::to_string(minor) + "/uevent");
if (!ueventFile)
return std::string();
while (ueventFile >> line) {
if (line.find("DEVNAME=") == 0) {
deviceNode = "/dev/" + line.substr(strlen("DEVNAME="));
break;
}
}
ueventFile.close();
return deviceNode;
}
} /* namespace libcamera */
|
