From patchwork Thu May 2 23:42:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Elder X-Patchwork-Id: 1150 Return-Path: Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 4114860E55 for ; Fri, 3 May 2019 01:42:59 +0200 (CEST) Received: from localhost.localdomain (unknown [96.44.9.117]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 367172D1; Fri, 3 May 2019 01:42:58 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1556840578; bh=chXJBwxUeFkqFHPrNGttYXCmw93g3WeioAfE2K4G3AE=; h=From:To:Cc:Subject:Date:From; b=nZc0ZoeJt0NY5sy1jzsV5L8RziG7krsjT6l4TWeHB+qNjODifNsWi+ftPxrJIkT3W Dd/hrn1Ca5Csc3cFYkml6CE78vOKOHKpzq79PWriDRWeRGNS1ZcDEh95jFsgFSsmUf YV2RVfdlwAGiQqm5yzurzMintWc37YGJUOzlSOj0= From: Paul Elder To: libcamera-devel@lists.libcamera.org Date: Thu, 2 May 2019 19:42:48 -0400 Message-Id: <20190502234248.15722-1-paul.elder@ideasonboard.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Subject: [libcamera-devel] [PATCH v2] 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 23:42:59 -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 --- Changes in v2: - style changes - change sysfs directory checking list to remove block and add subsystem - add warning output to alert if media device (/dev/media*) should exist based on sysfs but doesn't Documentation/Doxyfile.in | 4 +- src/libcamera/device_enumerator.cpp | 6 +- src/libcamera/device_enumerator_sysfs.cpp | 110 ++++++++++++++++++ .../include/device_enumerator_sysfs.h | 31 +++++ src/libcamera/meson.build | 2 + 5 files changed, 150 insertions(+), 3 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..381f777 100644 --- a/Documentation/Doxyfile.in +++ b/Documentation/Doxyfile.in @@ -833,7 +833,9 @@ RECURSIVE = YES # Note that relative paths are relative to the directory from which doxygen is # run. -EXCLUDE = ../src/libcamera/device_enumerator_udev.cpp \ +EXCLUDE = ../src/libcamera/device_enumerator_sysfs.cpp \ + ../src/libcamera/device_enumerator_udev.cpp \ + ../src/libcamera/include/device_enumerator_sysfs.h \ ../src/libcamera/include/device_enumerator_udev.h \ ../src/libcamera/pipeline/ diff --git a/src/libcamera/device_enumerator.cpp b/src/libcamera/device_enumerator.cpp index f6878b3..259eec4 100644 --- a/src/libcamera/device_enumerator.cpp +++ b/src/libcamera/device_enumerator.cpp @@ -6,6 +6,7 @@ */ #include "device_enumerator.h" +#include "device_enumerator_sysfs.h" #include "device_enumerator_udev.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..943cab2 --- /dev/null +++ b/src/libcamera/device_enumerator_sysfs.cpp @@ -0,0 +1,110 @@ +/* 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 +#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; + DIR *dir; + + static const char *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; + } + + while ((ent = readdir(dir)) != nullptr) { + unsigned int idx; + struct stat devstat; + char *end; + std::string devnode; + + 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) { + 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 */ diff --git a/src/libcamera/include/device_enumerator_sysfs.h b/src/libcamera/include/device_enumerator_sysfs.h new file mode 100644 index 0000000..534b28c --- /dev/null +++ b/src/libcamera/include/device_enumerator_sysfs.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 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 final : public DeviceEnumerator +{ +public: + DeviceEnumeratorSysfs(); + ~DeviceEnumeratorSysfs(); + + int init(); + int enumerate(); + +private: + std::string lookupDeviceNode(int major, int minor); +}; + +} /* namespace libcamera */ + +#endif /* __LIBCAMERA_DEVICE_ENUMERATOR_SYSFS_H__ */ diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build index 2b67823..8796f49 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', @@ -26,6 +27,7 @@ libcamera_sources = files([ libcamera_headers = files([ 'include/camera_sensor.h', 'include/device_enumerator.h', + 'include/device_enumerator_sysfs.h', 'include/device_enumerator_udev.h', 'include/event_dispatcher_poll.h', 'include/formats.h',