From patchwork Thu May 2 21:26:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Elder X-Patchwork-Id: 1149 Return-Path: Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id E3E6360E5F for ; Thu, 2 May 2019 23:27:33 +0200 (CEST) Received: from localhost.localdomain (unknown [96.44.9.117]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id DEF8C2D1; Thu, 2 May 2019 23:27:32 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1556832453; bh=dby128YADk13VoY1VwZO/VIxKMW25HG2iYDyD5LVnDA=; h=From:To:Cc:Subject:Date:From; b=t3l3PvERfaScb5EHi1ZEzHMVIeeeahJax+N5LJRndbKfgOo0/H274db3/O8Cbf2A1 T6Tj4mxLHx6UaurC2R1VPmd9RAtnt02szi9ertE8roYcY/C7WFQ3RTrInRClYFNpd9 A0pfsouPy240ViHb3wYc3PsUoJ7FArc/ksZGcO7Y= From: Paul Elder To: libcamera-devel@lists.libcamera.org Date: Thu, 2 May 2019 17:26:51 -0400 Message-Id: <20190502212651.4279-1-paul.elder@ideasonboard.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Subject: [libcamera-devel] [PATCH] libcamera: device_enumerator: add DeviceEnumeratorSysfs class X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 May 2019 21:27:34 -0000 A udev-based device enumerator is not sufficient, since libudev is an optional dependency, or udev might fail. In these cases, we should fall back to using sysfs to enumerate devices. Add a DeviceEnumeratorSysfs class which is a specialization of DeviceEnumerator that uses sysfs to enumerate media devices on the system. Signed-off-by: Paul Elder --- Documentation/Doxyfile.in | 2 + src/libcamera/device_enumerator.cpp | 6 +- src/libcamera/device_enumerator_sysfs.cpp | 109 ++++++++++++++++++ .../include/device_enumerator_sysfs.h | 31 +++++ src/libcamera/meson.build | 2 + 5 files changed, 148 insertions(+), 2 deletions(-) create mode 100644 src/libcamera/device_enumerator_sysfs.cpp create mode 100644 src/libcamera/include/device_enumerator_sysfs.h diff --git a/Documentation/Doxyfile.in b/Documentation/Doxyfile.in index 950ad4f..5dd4445 100644 --- a/Documentation/Doxyfile.in +++ b/Documentation/Doxyfile.in @@ -835,6 +835,8 @@ RECURSIVE = YES EXCLUDE = ../src/libcamera/device_enumerator_udev.cpp \ ../src/libcamera/include/device_enumerator_udev.h \ + ../src/libcamera/device_enumerator_sysfs.cpp \ + ../src/libcamera/include/device_enumerator_sysfs.h \ ../src/libcamera/pipeline/ # The EXCLUDE_SYMLINKS tag can be used to select whether or not files or diff --git a/src/libcamera/device_enumerator.cpp b/src/libcamera/device_enumerator.cpp index f6878b3..5c44eb1 100644 --- a/src/libcamera/device_enumerator.cpp +++ b/src/libcamera/device_enumerator.cpp @@ -7,6 +7,7 @@ #include "device_enumerator.h" #include "device_enumerator_udev.h" +#include "device_enumerator_sysfs.h" #include @@ -153,8 +154,9 @@ std::unique_ptr DeviceEnumerator::create() * Either udev is not available or udev initialization failed. Fall back * on the sysfs enumerator. */ - - /** \todo Add a sysfs-based enumerator. */ + enumerator = utils::make_unique(); + if (!enumerator->init()) + return enumerator; return nullptr; } diff --git a/src/libcamera/device_enumerator_sysfs.cpp b/src/libcamera/device_enumerator_sysfs.cpp new file mode 100644 index 0000000..6dd04e8 --- /dev/null +++ b/src/libcamera/device_enumerator_sysfs.cpp @@ -0,0 +1,109 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2018-2019, Google Inc. + * + * device_enumerator_sysfs.cpp - udev-based device enumerator + */ + +#include "device_enumerator_sysfs.h" + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "log.h" + +namespace libcamera { + +LOG_DECLARE_CATEGORY(DeviceEnumerator) + +DeviceEnumeratorSysfs::DeviceEnumeratorSysfs() +{ +} + +DeviceEnumeratorSysfs::~DeviceEnumeratorSysfs() +{ +} + +int DeviceEnumeratorSysfs::init() +{ + return 0; +} + +int DeviceEnumeratorSysfs::enumerate() +{ + struct dirent *ent; + struct stat devstat; + char *end; + DIR *dir; + + static const char *sysfs_dirs[] = { + "/sys/media/devices", + "/sys/block/media/devices", + "/sys/bus/media/devices", + "/sys/class/media/devices", + }; + + for (const char *dirname : sysfs_dirs) { + dir = opendir(dirname); + if (dir) + break; + } + + while ((ent = readdir(dir)) != nullptr) { + unsigned int idx; + std::string devnode = std::string(); + + if (strncmp(ent->d_name, "media", 5)) + continue; + + idx = strtoul(ent->d_name + 5, &end, 10); + if (*end != '\0') + continue; + + devnode = "/dev/media" + std::to_string(idx); + + /* Verify that the device node exists. */ + if (stat(devnode.c_str(), &devstat) < 0) + continue; + + addDevice(devnode); + } + + closedir(dir); + + return 0; +} + +std::string DeviceEnumeratorSysfs::lookupDeviceNode(int major, int minor) +{ + std::string deviceNode = std::string(); + std::string line = std::string(); + std::ifstream uevent_file; + size_t c_cnt; + + uevent_file.open("/sys/dev/char/" + std::to_string(major) + ":" + + std::to_string(minor) + "/uevent"); + if (!uevent_file) + return std::string(); + + while (uevent_file >> line) { + if (line.find("DEVNAME") != std::string::npos) { + c_cnt = line.find("="); + deviceNode = "/dev/" + line.substr(c_cnt + 1); + break; + } + } + + uevent_file.close(); + + return deviceNode; +} + +} /* namespace libcamera */ diff --git a/src/libcamera/include/device_enumerator_sysfs.h b/src/libcamera/include/device_enumerator_sysfs.h new file mode 100644 index 0000000..f32d6ae --- /dev/null +++ b/src/libcamera/include/device_enumerator_sysfs.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2018-2019, Google Inc. + * + * device_enumerator_sysfs.h - sysfs-based device enumerator + */ +#ifndef __LIBCAMERA_DEVICE_ENUMERATOR_SYSFS_H__ +#define __LIBCAMERA_DEVICE_ENUMERATOR_SYSFS_H__ + +#include + +#include "device_enumerator.h" + +namespace libcamera { + +class DeviceEnumeratorSysfs : public DeviceEnumerator +{ +public: + DeviceEnumeratorSysfs(); + ~DeviceEnumeratorSysfs(); + + int init() final; + int enumerate() final; + +private: + std::string lookupDeviceNode(int major, int minor) final; +}; + +} /* namespace libcamera */ + +#endif /* __LIBCAMERA_DEVICE_ENUMERATOR_SYSFS_H__ */ diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build index 2b67823..ca9ed7a 100644 --- a/src/libcamera/meson.build +++ b/src/libcamera/meson.build @@ -4,6 +4,7 @@ libcamera_sources = files([ 'camera_manager.cpp', 'camera_sensor.cpp', 'device_enumerator.cpp', + 'device_enumerator_sysfs.cpp', 'event_dispatcher.cpp', 'event_dispatcher_poll.cpp', 'event_notifier.cpp', @@ -27,6 +28,7 @@ libcamera_headers = files([ 'include/camera_sensor.h', 'include/device_enumerator.h', 'include/device_enumerator_udev.h', + 'include/device_enumerator_sysfs.h', 'include/event_dispatcher_poll.h', 'include/formats.h', 'include/log.h',