{"id":9158,"url":"https://patchwork.libcamera.org/api/1.1/patches/9158/?format=json","web_url":"https://patchwork.libcamera.org/patch/9158/","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":"<20200803211733.1037019-5-niklas.soderlund@ragnatech.se>","date":"2020-08-03T21:17:28","name":"[libcamera-devel,v6,4/9] libcamera: utils: Add method to lookup firmware ID in sysfs","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"61f6a91c0409f66053f830a0d73b0b583c17da8c","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/9158/mbox/","series":[{"id":1185,"url":"https://patchwork.libcamera.org/api/1.1/series/1185/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=1185","date":"2020-08-03T21:17:24","name":"libcamera: Generate unique and stable camera IDs","version":6,"mbox":"https://patchwork.libcamera.org/series/1185/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/9158/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/9158/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 26877BD87B\n\tfor ;\n\tMon, 3 Aug 2020 21:18:05 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id D2E7D61B02;\n\tMon, 3 Aug 2020 23:18:04 +0200 (CEST)","from vsp-unauthed02.binero.net (vsp-unauthed02.binero.net\n\t[195.74.38.227])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id B7F54605A9\n\tfor ;\n\tMon, 3 Aug 2020 23:18:01 +0200 (CEST)","from bismarck.berto.se (p54ac52a8.dip0.t-ipconnect.de\n\t[84.172.82.168]) by bin-vsp-out-03.atm.binero.net (Halon) with ESMTPA\n\tid 9db76d77-d5ce-11ea-86ee-0050569116f7;\n\tMon, 03 Aug 2020 23:16:37 +0200 (CEST)"],"X-Halon-ID":"9db76d77-d5ce-11ea-86ee-0050569116f7","Authorized-sender":"niklas@soderlund.pp.se","From":"=?utf-8?q?Niklas_S=C3=B6derlund?= ","To":"libcamera-devel@lists.libcamera.org","Date":"Mon, 3 Aug 2020 23:17:28 +0200","Message-Id":"<20200803211733.1037019-5-niklas.soderlund@ragnatech.se>","X-Mailer":"git-send-email 2.28.0","In-Reply-To":"<20200803211733.1037019-1-niklas.soderlund@ragnatech.se>","References":"<20200803211733.1037019-1-niklas.soderlund@ragnatech.se>","MIME-Version":"1.0","Subject":"[libcamera-devel] [PATCH v6 4/9] libcamera: utils: Add method to\n\tlookup firmware ID in sysfs","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":"A devices firmware description is recorded differently in sysfs\ndepending on if the devices uses OF or ACPI. Add a helper to abstract\nthis, allowing users to not care which of the two are used.\n\nFor OF-based systems the ID is the full path of the device in the\ndevice tree description. For ACPI-based systems the ID is the ACPI\nfirmware nodes path. Both ID sources are guaranteed to be unique and\npersistent as long as the firmware of the system is not changed.\n\nSigned-off-by: Niklas Söderlund \n---\n include/libcamera/internal/utils.h | 2 +\n src/libcamera/utils.cpp | 61 ++++++++++++++++++++++++++++++\n 2 files changed, 63 insertions(+)","diff":"diff --git a/include/libcamera/internal/utils.h b/include/libcamera/internal/utils.h\nindex 45cd6f120c51586b..69977340e2593db6 100644\n--- a/include/libcamera/internal/utils.h\n+++ b/include/libcamera/internal/utils.h\n@@ -200,6 +200,8 @@ details::StringSplitter split(const std::string &str, const std::string &delim);\n std::string libcameraBuildPath();\n std::string libcameraSourcePath();\n \n+int tryLookupFirmwareID(const std::string &devPath, std::string *id);\n+\n constexpr unsigned int alignDown(unsigned int value, unsigned int alignment)\n {\n \treturn value / alignment * alignment;\ndiff --git a/src/libcamera/utils.cpp b/src/libcamera/utils.cpp\nindex 615df46ac142a2a9..07ebce61f230e5f0 100644\n--- a/src/libcamera/utils.cpp\n+++ b/src/libcamera/utils.cpp\n@@ -9,6 +9,7 @@\n \n #include \n #include \n+#include \n #include \n #include \n #include \n@@ -444,6 +445,66 @@ std::string libcameraSourcePath()\n \treturn path + \"/\";\n }\n \n+/**\n+ * \\brief Try to read a device firmware ID from sysfs\n+ * \\param[in] devPath Path in sysfs to search\n+ * \\param[out] id Location to store ID if found\n+ *\n+ * The ID recorded in the devices firmware description is recorded differently\n+ * in sysfs depending on if the devices uses OF or ACPI. This helper abstracts\n+ * this away, allowing callers to not care which of the two are used.\n+ *\n+ * For OF-based systems the ID is the full path of the device in the device tree\n+ * description. For ACPI-based systems the ID is the ACPI firmware nodes path.\n+ * Both ID sources are guaranteed to be unique and persistent as long as the\n+ * firmware of the system is not changed.\n+ *\n+ * \\return 0 on success or a negative error code otherwise\n+ * \\retval -ENOMEM \\a id is nullptr\n+ * \\retval -EINVAL Error when looking up firmware ID\n+ * \\retval -ENODEV No firmware ID aviable for device\n+ */\n+int tryLookupFirmwareID(const std::string &devPath, std::string *id)\n+{\n+\tstruct stat statbuf;\n+\tstd::string path;\n+\n+\tif (!id)\n+\t\treturn -EINVAL;\n+\n+\t/* Try to lookup ID as if the system where OF-based. */\n+\tpath = devPath + \"/of_node\";\n+\tif (stat(path.c_str(), &statbuf) == 0) {\n+\t\tchar *ofPath = realpath(path.c_str(), nullptr);\n+\t\tif (!ofPath)\n+\t\t\treturn -EINVAL;\n+\n+\t\t*id = ofPath;\n+\t\tfree(ofPath);\n+\n+\t\tstatic const std::string dropStr = \"/sys/firmware/devicetree/\";\n+\t\tif (id->find(dropStr) == 0)\n+\t\t\tid->erase(0, dropStr.length());\n+\n+\t\treturn 0;\n+\t}\n+\n+\t/* Try to lookup ID as if the system where ACPI-based. */\n+\tpath = devPath + \"/firmware_node/path\";\n+\tif (stat(path.c_str(), &statbuf) == 0) {\n+\t\tstd::ifstream file(path.c_str());\n+\t\tif (!file.is_open())\n+\t\t\treturn -EINVAL;\n+\n+\t\tstd::getline(file, *id);\n+\t\tfile.close();\n+\n+\t\treturn 0;\n+\t}\n+\n+\treturn -ENODEV;\n+}\n+\n /**\n * \\fn alignDown(unsigned int value, unsigned int alignment)\n * \\brief Align \\a value down to \\a alignment\n","prefixes":["libcamera-devel","v6","4/9"]}