{"id":246,"url":"https://patchwork.libcamera.org/api/patches/246/?format=json","web_url":"https://patchwork.libcamera.org/patch/246/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20190115231909.19893-3-kieran.bingham@ideasonboard.com>","date":"2019-01-15T23:19:08","name":"[libcamera-devel,v3,2/3] libcamera: Add V4L2 Device object","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"e3e19ed80a8936a4067feebe1eefc498166ba552","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/?format=json","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/246/mbox/","series":[{"id":83,"url":"https://patchwork.libcamera.org/api/series/83/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=83","date":"2019-01-15T23:19:06","name":"V4L2Device: Add basic V4L2 support class","version":3,"mbox":"https://patchwork.libcamera.org/series/83/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/246/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/246/checks/","tags":{},"headers":{"Return-Path":"","Received":["from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id B833A60C99\n\tfor ;\n\tWed, 16 Jan 2019 00:19:14 +0100 (CET)","from localhost.localdomain\n\t(cpc89242-aztw30-2-0-cust488.18-1.cable.virginm.net [86.31.129.233])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 4BC7459B;\n\tWed, 16 Jan 2019 00:19:14 +0100 (CET)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1547594354;\n\tbh=FQJYXug8xH804kBrb/lkuYcfnUl9OY4Jsv787CWa7rQ=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=R/r/mMAe2wjWPYu2+ZddSYVTM5iD6pul9eNq0n5Sb9rPkN5DCI+WJsmr96VAaVeMf\n\twTETCX1kXkaM3ko25CATeiNrxLEzjZxWemwfrUy/TBWaD/AKrbnBaVAUzz1N1yuuil\n\toexk8x10IMacLEMXCm8RVsBFlU/9IFbs6UaqVo6k=","From":"Kieran Bingham ","To":"LibCamera Devel ","Date":"Tue, 15 Jan 2019 23:19:08 +0000","Message-Id":"<20190115231909.19893-3-kieran.bingham@ideasonboard.com>","X-Mailer":"git-send-email 2.17.1","In-Reply-To":"<20190115231909.19893-1-kieran.bingham@ideasonboard.com>","References":"<20190115231909.19893-1-kieran.bingham@ideasonboard.com>","Subject":"[libcamera-devel] [PATCH v3 2/3] libcamera: Add V4L2 Device object","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.23","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","X-List-Received-Date":"Tue, 15 Jan 2019 23:19:14 -0000"},"content":"Provide a helper V4L2 device object capable of interacting with the\nV4L2 Linux Kernel APIs.\n\nSigned-off-by: Kieran Bingham \n---\n src/libcamera/include/v4l2_device.h | 45 +++++++++\n src/libcamera/meson.build | 2 +\n src/libcamera/v4l2_device.cpp | 150 ++++++++++++++++++++++++++++\n 3 files changed, 197 insertions(+)\n create mode 100644 src/libcamera/include/v4l2_device.h\n create mode 100644 src/libcamera/v4l2_device.cpp","diff":"diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h\nnew file mode 100644\nindex 000000000000..b0f5e9689654\n--- /dev/null\n+++ b/src/libcamera/include/v4l2_device.h\n@@ -0,0 +1,45 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2019, Google Inc.\n+ *\n+ * v4l2_device.h - V4L2 Device\n+ */\n+#ifndef __LIBCAMERA_V4L2_DEVICE_H__\n+#define __LIBCAMERA_V4L2_DEVICE_H__\n+\n+#include \n+\n+#include \n+\n+namespace libcamera {\n+\n+class V4L2Capability : public v4l2_capability\n+{\n+public:\n+\tstd::string getDriver() const { return std::string((char *)driver); }\n+\tstd::string getCard() const { return std::string((char *)card); }\n+\n+\tbool isCapture() const { return capabilities & V4L2_CAP_VIDEO_CAPTURE; }\n+\tbool hasStreaming() const { return capabilities & V4L2_CAP_STREAMING; }\n+};\n+\n+class V4L2Device\n+{\n+public:\n+\tV4L2Device() = delete;\n+\tV4L2Device(const std::string &devnode);\n+\t~V4L2Device();\n+\n+\tint open();\n+\tbool isOpen() const;\n+\tvoid close();\n+\n+private:\n+\tstd::string devnode_;\n+\tint fd_;\n+\tV4L2Capability caps_;\n+};\n+\n+} /* namespace libcamera */\n+\n+#endif /* __LIBCAMERA_V4L2_DEVICE_H__ */\ndiff --git a/src/libcamera/meson.build b/src/libcamera/meson.build\nindex abf9a71d4172..f9f25c0ecf15 100644\n--- a/src/libcamera/meson.build\n+++ b/src/libcamera/meson.build\n@@ -11,6 +11,7 @@ libcamera_sources = files([\n 'pipeline_handler.cpp',\n 'signal.cpp',\n 'timer.cpp',\n+ 'v4l2_device.cpp',\n ])\n \n libcamera_headers = files([\n@@ -21,6 +22,7 @@ libcamera_headers = files([\n 'include/media_object.h',\n 'include/pipeline_handler.h',\n 'include/utils.h',\n+ 'include/v4l2_device.h',\n ])\n \n libcamera_internal_includes = include_directories('include')\ndiff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp\nnew file mode 100644\nindex 000000000000..8c49d3ff56e2\n--- /dev/null\n+++ b/src/libcamera/v4l2_device.cpp\n@@ -0,0 +1,150 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2019, Google Inc.\n+ *\n+ * v4l2_device.cpp - V4L2 Device\n+ */\n+\n+#include \n+#include \n+#include \n+#include \n+#include \n+\n+#include \"log.h\"\n+#include \"v4l2_device.h\"\n+\n+/**\n+ * \\file v4l2_device.h\n+ * \\brief V4L2 Device API\n+ */\n+namespace libcamera {\n+\n+/**\n+ * \\class V4L2Capability\n+ * \\brief struct v4l2_capability object wrapper and helpers\n+ *\n+ * The V4L2Capability class manages the information returned by the\n+ * VIDIOC_QUERYCAP ioctl.\n+ */\n+\n+/**\n+ * \\fn std::string V4L2Capability::getDriver()\n+ * \\brief Retrieve the driver module name\n+ * \\return The string containing the name of the driver module\n+ */\n+\n+/**\n+ * \\fn std::string V4L2Capability::getCard()\n+ * \\brief Retrieve the device card name\n+ * \\return The string containing the device name\n+ */\n+\n+/**\n+ * \\fn bool V4L2Capability::isCapture()\n+ * \\brief Identify if the device is capable of capturing video\n+ * \\return boolean true if the device provides video frames\n+ */\n+\n+/**\n+ * \\fn bool V4L2Capability::hasStreaming()\n+ * \\brief Determine if the device can perform Streaming IO\n+ * \\return boolean true if the device provides Streaming IO IOCTLs\n+ */\n+\n+/**\n+ * \\class V4L2Device\n+ * \\brief V4L2Device object and API.\n+ *\n+ * The V4L2 Device API class models an instance of a V4L2 device node.\n+ * It is constructed with the path to a V4L2 video device node. The device node\n+ * is only opened upon a call to open() which must be checked for success.\n+ *\n+ * The device capabilities are validated and the device is rejected if it is\n+ * not a suitable capture device.\n+ *\n+ * No API call (except open(), isOpen() and close()) shall be called on an\n+ * unopened device instance.\n+ *\n+ * Upon destruction any device left open will be closed, and any resources\n+ * released.\n+ */\n+\n+/**\n+ * \\brief Construct a V4L2Device\n+ * \\param devnode The file-system path to the video device node\n+ */\n+V4L2Device::V4L2Device(const std::string &devnode)\n+\t: devnode_(devnode), fd_(-1)\n+{\n+}\n+\n+V4L2Device::~V4L2Device()\n+{\n+\tclose();\n+}\n+\n+/**\n+ * \\brief Open a V4L2 device and query properties from the device.\n+ * \\return 0 on success, or a negative error code otherwise\n+ */\n+int V4L2Device::open()\n+{\n+\tint ret;\n+\n+\tif (isOpen()) {\n+\t\tLOG(Error) << \"Device already open\";\n+\t\treturn -EBUSY;\n+\t}\n+\n+\tret = ::open(devnode_.c_str(), O_RDWR);\n+\tif (ret < 0) {\n+\t\tret = -errno;\n+\t\tLOG(Error) << \"Failed to open V4L2 device \" << devnode_\n+\t\t\t << \" : \" << strerror(ret);\n+\t\treturn ret;\n+\t}\n+\tfd_ = ret;\n+\n+\tret = ioctl(fd_, VIDIOC_QUERYCAP, &caps_);\n+\tif (ret < 0) {\n+\t\tLOG(Error) << \"Failed to query device capabilities: \" << strerror(errno);\n+\t\treturn -errno;\n+\t}\n+\n+\tLOG(Debug) << \"Opened '\" << devnode_ << \"' \" << caps_.getDriver() << \": \" << caps_.getCard();\n+\n+\tif (!(caps_.isCapture())) {\n+\t\tLOG(Error) << \"Device is not a capture device\";\n+\t\treturn -EINVAL;\n+\t}\n+\n+\tif (!(caps_.hasStreaming())) {\n+\t\tLOG(Error) << \"Device does not support streaming IO\";\n+\t\treturn -EINVAL;\n+\t}\n+\n+\treturn 0;\n+}\n+\n+/**\n+ * \\brief Check if device is successfully opened\n+ */\n+bool V4L2Device::isOpen() const\n+{\n+\treturn (fd_ != -1);\n+}\n+\n+/**\n+ * \\brief Close the device, releasing any resources acquired by open()\n+ */\n+void V4L2Device::close()\n+{\n+\tif (fd_ < 0)\n+\t\treturn;\n+\n+\t::close(fd_);\n+\tfd_ = -1;\n+}\n+\n+} /* namespace libcamera */\n","prefixes":["libcamera-devel","v3","2/3"]}