{"id":25655,"url":"https://patchwork.libcamera.org/api/patches/25655/?format=json","web_url":"https://patchwork.libcamera.org/patch/25655/","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":"<20260106170059.56193-3-bryan.odonoghue@linaro.org>","date":"2026-01-06T17:00:37","name":"[v11,02/24] libcamera: software_isp: gbm: Add a GBM helper class for GPU surface access","commit_ref":"c60b1ce8193841c2742b655097bb39ccbcb417c2","pull_url":null,"state":"accepted","archived":false,"hash":"586ee348ce1a47596b83bcb6f0972a6556fbce8e","submitter":{"id":175,"url":"https://patchwork.libcamera.org/api/people/175/?format=json","name":"Bryan O'Donoghue","email":"bryan.odonoghue@linaro.org"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/25655/mbox/","series":[{"id":5689,"url":"https://patchwork.libcamera.org/api/series/5689/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5689","date":"2026-01-06T17:00:35","name":"Add GLES 2.0 GPUISP to libcamera","version":10,"mbox":"https://patchwork.libcamera.org/series/5689/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/25655/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/25655/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 4229EBDCC0\n\tfor ;\n\tTue, 6 Jan 2026 17:01:10 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id EE4C661FE8;\n\tTue, 6 Jan 2026 18:01:09 +0100 (CET)","from mail-wr1-x444.google.com (mail-wr1-x444.google.com\n\t[IPv6:2a00:1450:4864:20::444])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 20B9E61F9F\n\tfor ;\n\tTue, 6 Jan 2026 18:01:07 +0100 (CET)","by mail-wr1-x444.google.com with SMTP id\n\tffacd0b85a97d-42fb2314eb0so867968f8f.2\n\tfor ;\n\tTue, 06 Jan 2026 09:01:07 -0800 (PST)","from inspiron14p-linux.ht.home (188-141-3-146.dynamic.upc.ie.\n\t[188.141.3.146]) by smtp.gmail.com with ESMTPSA id\n\tffacd0b85a97d-432bd0dadcfsm5515322f8f.3.2026.01.06.09.01.03\n\t(version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);\n\tTue, 06 Jan 2026 09:01:04 -0800 (PST)"],"Authentication-Results":"lancelot.ideasonboard.com; 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\n\tTue, 06 Jan 2026 09:01:04 -0800 (PST)","From":"Bryan O'Donoghue ","To":"libcamera-devel@lists.libcamera.org","Cc":"pavel@ucw.cz, Bryan O'Donoghue ,\n\tKieran Bingham ,\n\tMilan Zamazal ,\n\tRobert Mader ,\n\tHans de Goede ","Subject":"[PATCH v11 02/24] libcamera: software_isp: gbm: Add a GBM helper\n\tclass for GPU surface access","Date":"Tue, 6 Jan 2026 17:00:37 +0000","Message-ID":"<20260106170059.56193-3-bryan.odonoghue@linaro.org>","X-Mailer":"git-send-email 2.52.0","In-Reply-To":"<20260106170059.56193-1-bryan.odonoghue@linaro.org>","References":"<20260106170059.56193-1-bryan.odonoghue@linaro.org>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","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","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"A helper class to interact with GBM. This will allow us to specify the\ninternal storage format of the GPU when making a texture for the Debayer\nvertex/fragment shaders and thus ensure we receive an uncompressed and\nuntiled output buffer.\n\nAcked-by: Kieran Bingham \nReviewed-by: Milan Zamazal \nReviewed-by: Robert Mader \nTested-by: Hans de Goede # ThinkPad T14s gen 6 (arm64) ov02c10 + X1c gen 12 ov08x40\nSigned-off-by: Bryan O'Donoghue \n---\n include/libcamera/internal/gbm.h | 55 +++++++++++++\n include/libcamera/internal/meson.build | 1 +\n src/libcamera/gbm.cpp | 107 +++++++++++++++++++++++++\n src/libcamera/meson.build | 10 +++\n 4 files changed, 173 insertions(+)\n create mode 100644 include/libcamera/internal/gbm.h\n create mode 100644 src/libcamera/gbm.cpp","diff":"diff --git a/include/libcamera/internal/gbm.h b/include/libcamera/internal/gbm.h\nnew file mode 100644\nindex 000000000..c10be06c1\n--- /dev/null\n+++ b/include/libcamera/internal/gbm.h\n@@ -0,0 +1,55 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2024, Linaro Ltd.\n+ *\n+ * Authors:\n+ * Bryan O'Donoghue \n+ *\n+ * Helper class for managing GBM interactions\n+ */\n+\n+#pragma once\n+\n+#include \n+\n+#include \n+#include \n+\n+#include \n+\n+namespace libcamera {\n+\n+LOG_DECLARE_CATEGORY(GBM)\n+\n+class GBM\n+{\n+public:\n+\tGBM();\n+\t~GBM();\n+\n+\tint createDevice();\n+\n+\t/**\n+\t * \\brief Retrieve the GBM device handle\n+\t *\n+\t * \\return Pointer to the gbm_device structure, or nullptr if the device\n+\t * has not been created\n+\t */\n+\tstruct gbm_device *device() const { return gbmDevice_; }\n+\n+\t/**\n+\t * \\brief Retrieve the pixel format\n+\t *\n+\t * \\return The PixelFormat used by this GBM instance (ARGB8888)\n+\t */\n+\tPixelFormat format() const { return format_; }\n+\n+private:\n+\tLIBCAMERA_DISABLE_COPY_AND_MOVE(GBM)\n+\n+\tUniqueFD fd_;\n+\tstruct gbm_device *gbmDevice_ = nullptr;\n+\tPixelFormat format_;\n+};\n+\n+} /* namespace libcamera */\ndiff --git a/include/libcamera/internal/meson.build b/include/libcamera/internal/meson.build\nindex e9540a2f7..b8324996b 100644\n--- a/include/libcamera/internal/meson.build\n+++ b/include/libcamera/internal/meson.build\n@@ -23,6 +23,7 @@ libcamera_internal_headers = files([\n 'dma_buf_allocator.h',\n 'formats.h',\n 'framebuffer.h',\n+ 'gbm.h',\n 'global_configuration.h',\n 'ipa_data_serializer.h',\n 'ipa_manager.h',\ndiff --git a/src/libcamera/gbm.cpp b/src/libcamera/gbm.cpp\nnew file mode 100644\nindex 000000000..d37808b0c\n--- /dev/null\n+++ b/src/libcamera/gbm.cpp\n@@ -0,0 +1,107 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2024, Linaro Ltd.\n+ *\n+ * Authors:\n+ * Bryan O'Donoghue \n+ *\n+ * Helper class for managing GBM interactions\n+ */\n+\n+#include \"libcamera/internal/gbm.h\"\n+\n+#include \n+#include \n+#include \n+#include \n+#include \n+\n+#include \n+#include \n+\n+namespace libcamera {\n+\n+LOG_DEFINE_CATEGORY(GBM)\n+\n+/**\n+ * \\class GBM\n+ * \\brief Helper class for managing GBM interactions\n+ *\n+ * The GBM class provides a simplified interface for creating and managing\n+ * GBM devices. It handles the initialization and teardown of GBM devices\n+ * used for buffer allocation in graphics and camera pipelines.\n+ *\n+ * This class is responsible for opening a DRI render node, creating a GBM\n+ * device, and providing access to the device and its associated pixel format.\n+ */\n+\n+/**\n+ *\\var GBM::fd_\n+ *\\brief file descriptor to DRI device\n+ */\n+\n+/**\n+ *\\var GBM::gbmDevice_\n+ *\\brief Pointer to GBM device structure derived from fd_\n+ */\n+\n+/**\n+ *\\var GBM::format_\n+ *\\brief Pixel format the GBM surface was created in\n+ */\n+\n+/**\n+ *\\brief GBM constructor.\n+ *\n+ * Creates a GBM instance with uninitialised state.\n+ */\n+GBM::GBM()\n+{\n+}\n+\n+/**\n+ *\\brief GBM destructor\n+ *\n+ * Cleans up the GBM device if it was successfully created, and closes\n+ * the associated file descriptor.\n+ */\n+GBM::~GBM()\n+{\n+\tif (gbmDevice_)\n+\t\tgbm_device_destroy(gbmDevice_);\n+}\n+\n+/**\n+ * \\brief Create and initialize a GBM device\n+ *\n+ * \\todo Get dri device name from envOption setting\n+ *\n+ * Opens the DRI render node (/dev/dri/renderD128) and creates a GBM\n+ * device using the libgbm library. Sets the default pixel format to\n+ * ARGB8888.\n+ *\n+ * \\return 0 on success, or a negative error code on failure\n+ */\n+int GBM::createDevice()\n+{\n+\tconst char dri_node[] = \"/dev/dri/renderD128\";\n+\n+\tint fd = open(dri_node, O_RDWR | O_CLOEXEC | O_NOCTTY);\n+\tif (fd < 0) {\n+\t\tLOG(GBM, Error) << \"Open \" << dri_node << \" fail \" << strerror(errno);\n+\t\treturn -errno;\n+\t}\n+\tfd_ = UniqueFD(fd);\n+\n+\tgbmDevice_ = gbm_create_device(fd_.get());\n+\tif (!gbmDevice_) {\n+\t\tLOG(GBM, Error) << \"gbm_create_device fail\" << strerror(errno);\n+\t\treturn -errno;\n+\t}\n+\n+\tformat_ = libcamera::formats::ARGB8888;\n+\n+\treturn 0;\n+}\n+\n+} /* namespace libcamera */\ndiff --git a/src/libcamera/meson.build b/src/libcamera/meson.build\nindex 575408b2c..cb7863852 100644\n--- a/src/libcamera/meson.build\n+++ b/src/libcamera/meson.build\n@@ -70,6 +70,15 @@ libcamera_deps = []\n libatomic = cc.find_library('atomic', required : false)\n libthreads = dependency('threads')\n \n+libgbm = dependency('gbm', required : false)\n+gbm_works = cc.check_header('gbm.h', required: false)\n+\n+if libgbm.found() and gbm_works\n+ libcamera_internal_sources += files([\n+ 'gbm.cpp',\n+ ])\n+endif\n+\n subdir('base')\n subdir('converter')\n subdir('ipa')\n@@ -178,6 +187,7 @@ libcamera_deps += [\n libcamera_base_private,\n libcrypto,\n libdl,\n+ libgbm,\n liblttng,\n libudev,\n libyaml,\n","prefixes":["v11","02/24"]}