{"id":9210,"url":"https://patchwork.libcamera.org/api/1.1/patches/9210/?format=json","web_url":"https://patchwork.libcamera.org/patch/9210/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/1.1/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":"<20200805104900.2172763-4-niklas.soderlund@ragnatech.se>","date":"2020-08-05T10:48:54","name":"[libcamera-devel,v8,3/9] libcamera: v4l2_device: Add method to lookup device path","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"1cd6bfb5c481965ea58ff083c1c0f5f46e4b00eb","submitter":{"id":5,"url":"https://patchwork.libcamera.org/api/1.1/people/5/?format=json","name":"Niklas Söderlund","email":"niklas.soderlund@ragnatech.se"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/9210/mbox/","series":[{"id":1192,"url":"https://patchwork.libcamera.org/api/1.1/series/1192/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=1192","date":"2020-08-05T10:48:51","name":"libcamera: Generate unique and stable camera IDs","version":8,"mbox":"https://patchwork.libcamera.org/series/1192/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/9210/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/9210/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 228A1BD87B\n\tfor ;\n\tWed, 5 Aug 2020 10:49:17 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id CFDE4605A8;\n\tWed, 5 Aug 2020 12:49:16 +0200 (CEST)","from bin-mail-out-05.binero.net (bin-mail-out-05.binero.net\n\t[195.74.38.228])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 555A560555\n\tfor ;\n\tWed, 5 Aug 2020 12:49:13 +0200 (CEST)","from bismarck.berto.se (p54ac52a8.dip0.t-ipconnect.de\n\t[84.172.82.168]) by bin-vsp-out-02.atm.binero.net (Halon) with ESMTPA\n\tid 4c3c6404-d709-11ea-a39b-005056917f90;\n\tWed, 05 Aug 2020 12:49:12 +0200 (CEST)"],"X-Halon-ID":"4c3c6404-d709-11ea-a39b-005056917f90","Authorized-sender":"niklas@soderlund.pp.se","From":"=?utf-8?q?Niklas_S=C3=B6derlund?= ","To":"libcamera-devel@lists.libcamera.org","Date":"Wed, 5 Aug 2020 12:48:54 +0200","Message-Id":"<20200805104900.2172763-4-niklas.soderlund@ragnatech.se>","X-Mailer":"git-send-email 2.28.0","In-Reply-To":"<20200805104900.2172763-1-niklas.soderlund@ragnatech.se>","References":"<20200805104900.2172763-1-niklas.soderlund@ragnatech.se>","MIME-Version":"1.0","Subject":"[libcamera-devel] [PATCH v8 3/9] libcamera: v4l2_device: Add method\n\tto lookup device path","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"base64","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"Add a method to lookup a V4L2 devices path in sysfs.\n\nSigned-off-by: Niklas Söderlund \nReviewed-by: Laurent Pinchart \nReviewed-by: Jacopo Mondi \n---\n* Changes since v7\n- Expand comment\n- Update error message\n\n* Changes since v6\n- Use sysfs:: helper.\n- Do not try to return std::string { nullptr } on error.\n\n* Changes since v5\n- Expand documentation\n- Use DeviceEnumerator interface to lookup device path\n- Include stdlib.h\n- Use realpath(..., nullptr); ...; free();\n\n* Changes since v3\n- s/the device path/the device path in sysfs/\n---\n include/libcamera/internal/v4l2_device.h | 1 +\n src/libcamera/v4l2_device.cpp | 31 ++++++++++++++++++++++++\n 2 files changed, 32 insertions(+)","diff":"diff --git a/include/libcamera/internal/v4l2_device.h b/include/libcamera/internal/v4l2_device.h\nindex bf643f2ec966bb33..3b605aab343b3b94 100644\n--- a/include/libcamera/internal/v4l2_device.h\n+++ b/include/libcamera/internal/v4l2_device.h\n@@ -30,6 +30,7 @@ public:\n \tint setControls(ControlList *ctrls);\n \n \tconst std::string &deviceNode() const { return deviceNode_; }\n+\tstd::string devicePath() const;\n \n protected:\n \tV4L2Device(const std::string &deviceNode);\ndiff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp\nindex 56ea1ddda2c1425f..65830d41f3cb6e9d 100644\n--- a/src/libcamera/v4l2_device.cpp\n+++ b/src/libcamera/v4l2_device.cpp\n@@ -9,12 +9,15 @@\n \n #include \n #include \n+#include \n+#include \n #include \n #include \n #include \n #include \n \n #include \"libcamera/internal/log.h\"\n+#include \"libcamera/internal/sysfs.h\"\n #include \"libcamera/internal/utils.h\"\n #include \"libcamera/internal/v4l2_controls.h\"\n \n@@ -350,6 +353,34 @@ int V4L2Device::setControls(ControlList *ctrls)\n \treturn ret;\n }\n \n+/**\n+ * \\brief Retrieve the device path in sysfs\n+ *\n+ * This function returns the sysfs path to the physical device backing the V4L2\n+ * device. The path is guaranteed to be an absolute path, without any symbolic\n+ * link.\n+ *\n+ * It includes the sysfs mount point prefix\n+ *\n+ * \\return The device path in sysfs\n+ */\n+std::string V4L2Device::devicePath() const\n+{\n+\tstd::string devicePath = sysfs::charDevPath(deviceNode_) + \"/device\";\n+\n+\tchar *realPath = realpath(devicePath.c_str(), nullptr);\n+\tif (!realPath) {\n+\t\tLOG(V4L2, Fatal)\n+\t\t\t<< \"Can not resolve device path for \" << devicePath;\n+\t\treturn {};\n+\t}\n+\n+\tstd::string path{ realPath };\n+\tfree(realPath);\n+\n+\treturn path;\n+}\n+\n /**\n * \\brief Perform an IOCTL system call on the device node\n * \\param[in] request The IOCTL request code\n","prefixes":["libcamera-devel","v8","3/9"]}