From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38B01A95E; Sun, 27 Sep 2026 14:59:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790521152; cv=none; b=PIepxuScabwKHD2BWOWq2+N2ndLGpysJfKyGQArBQHaPBLbjqcBc5yor86MSJisTIuE7I8ZmJZrC2R8BQnTwh51/acyZy1ESGPfxU68mYqstdyhe1tK1qdtTAEWb8NMhr7CcntzEKuOlva51KGbH4OB7Zsdb55DUN8rhh10pKI8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790521152; c=relaxed/simple; bh=YmGxEJFzXbTFWzE7ulh7aHe3IiKiro4uJZWRmXMUOd0=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=X1Huz6dPhZov7BHDjeguZTylxTPg2SKqHAnwPUXt2uFBxr7sUQq/nD++Vp0A6VHH9JFCiZQYDdlDTmm7nbDKQD/TpncMxacwGQrkg7Mmve8IsefJgL/j+/iGbOLm47i0adpfdDzjocOHRzThy6BoQGuf+5BbvyDUh3som1CyF1U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=E8YsWMcz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="E8YsWMcz" Received: by smtp.kernel.org (Postfix) with ESMTPS id A3F1AC2BCB3; Sun, 27 Sep 2026 14:59:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1790521151; bh=YmGxEJFzXbTFWzE7ulh7aHe3IiKiro4uJZWRmXMUOd0=; h=From:Subject:Date:To:Cc:Reply-To:From; b=E8YsWMczeUFp/Ps4S1C35qOItIhMEQTogovptCnGpBA6Sr4GeuzG0hJraEZvjTUGs Hl4kqdt6pLem2wdOmwG2krvftXJe6z+fz8fvQ3BPaK9cCw0LX0vZTfFxyr0qoEgErt eAbi4OYCzDM0oQLH0hH62l3v1bwXj1iGPDlWJKgIhVs56iPq0NpUtipglxkUTYwjO0 B3/gwKWqhYpCCPmpV5rVeB2+ZTkMxI+nB0EXyGiU8o9MLpK8LUFrowhMesLHCIqw+z 92sdN3tMYDSP2a/N19QFg3M4qrzqBSXUCD+fwv+9UAuqc69XieSP1aCfIOPwjte2sI 8GjcQ1zmH0yFA== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F570C98332; Sun, 27 Sep 2026 14:59:11 +0000 (UTC) From: Vyacheslav Yurkov via B4 Relay Subject: [PATCH v8 0/2] A proposal to add a gpio-locked clock driver. Date: Sun, 27 Sep 2026 14:59:06 +0000 Message-Id: <20260927-feature-clock-guard-v8-0-630938e302a1@bruker.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIADovuWoC/43PTU7DMBAF4KtUXmNkj/9ZcQ/EYjx2WqvQIKeJQ FXujtNNQIkQyzfSfG/mxoZcSx7Y0+HGap7KUPpLC/7hwOiEl2PmJbXMQIAVSnreZbyONXN66+n MjyPWxDsQCKRMDNawtvlRc1c+7+rLa8unMlz7+nUvmeQy/dubJBfcSuUoauF1dM+xjudcH6l/Z ws4wYoYKfYRWBACo41PRmmxQdSKtFv2EdUQIYlQIAqNZoPoFXFg9xHdkBzIR+UgOkkbxKxIkGY fMQ3RgNEkUmgRN4j9gYDbR+zyjnDBqyhVJtgg7h+Ia4hPSQZjfQr4G5nn+Rskt7IkVQIAAA== X-Change-ID: 20260318-feature-clock-guard-f20a2c35b965 To: Michael Turquette , Stephen Boyd , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Brian Masney , Brian Masney , Jerome Brunet , Jyri Sarha Cc: linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, Vyacheslav Yurkov , Vyacheslav Yurkov X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1790521150; l=3080; i=V.Yurkov.EXT@bruker.com; s=20260318; h=from:subject:message-id; bh=YmGxEJFzXbTFWzE7ulh7aHe3IiKiro4uJZWRmXMUOd0=; b=8jdU/HvfBCRhKNpwUXhkVNz2Z1Nq5LWDI9YNTvgw1uO3VoBeFZGUgSDoEveJs6yWg8gx7UyDs AL+9oQytxlyCn0qaJAbwor0IKt7aCDTTAUG0Tu+GSlovK2g4EbvyXaJ X-Developer-Key: i=V.Yurkov.EXT@bruker.com; a=ed25519; pk=snJmgYVOKlp7aQtK9tWnEI7QTYxpPpJJvxdVsnxA7Fk= X-Endpoint-Received: by B4 Relay for V.Yurkov.EXT@bruker.com/20260318 with auth_id=686 X-Original-From: Vyacheslav Yurkov Reply-To: V.Yurkov.EXT@bruker.com A gpio-locked clock represents an input clock, which state is determined by a GPIO signal. It's similar to a gated-fixed-clock, but GPIO direction is inverted. Consumers can use the output clock to wait until all input clocks are locked and only then initialize / access dependent peripherals. The usage example for such a driver is when peripherals depend on PLLs in a FPGA, which can't be directly accessed by the CPU, but need a GPIO pin to check whether clock is actually usable. E.g. some of the IPs might not have a proper split between registers and IP core, which means that if an external clock and/or PLL lock is missing and one tries to access the registers, the response never comes, thus the CPU stalls. Signed-off-by: Vyacheslav Yurkov Signed-off-by: Vyacheslav Yurkov --- Changes in v8: - Fix return value of clk_gpio_locked_prepare() - Link to v7: https://lore.kernel.org/r/20260927-feature-clock-guard-v7-0-8dd19568d9a2@bruker.com Changes in v7: - Fix compatibility strings and schema errors. - Update GPIO pin name - Link to v6: https://lore.kernel.org/r/20260927-feature-clock-guard-v6-0-007983b13ec2@bruker.com Changes in v6: - Debug messages dropped. - The new driver is now an extension of exising clk-gpio drivers. - The controller doesn't enable the parent clock, the consumer is supposed to do that instead. - Link to v5: https://lore.kernel.org/r/20260915-feature-clock-guard-v5-0-42ab5dc3a6aa@bruker.com Changes in v5: - Use existing DT binding with an additional property instead of adding a new one - The driver is simplified in a way that it represents the actual HW desgin without additional unrelated constructs - Aggregation is removed, now it's one clock input, one clock output - Link to v4: https://lore.kernel.org/r/20260726-feature-clock-guard-v4-0-e9c8b372b71c@bruker.com Changes in v4: - Removed driver specifics from DT binding - Link to v3: https://lore.kernel.org/r/20260603-feature-clock-guard-v3-0-01cca0aa04a5@bruker.com Changes in v3: - Removed unnecessary dt bindings - Improved HW description and commit messages - Link to v2: https://lore.kernel.org/r/20260510-feature-clock-guard-v2-0-6c25458d5340@bruker.com Changes in v2: - Renamed to clk-gpio-locked to express intent. - Provide enable() / is_enabled() operations so the clock behaves as expected - Fixed DTS errors / warnings - Link to v1: https://lore.kernel.org/r/20260318-feature-clock-guard-v1-0-6137cb4084b7@bruker.com --- Vyacheslav Yurkov (2): dt-bindings: clock: gpio-gate-clock: Add a new compatible string clk: Add gpio-locked clock driver .../devicetree/bindings/clock/gpio-gate-clock.yaml | 32 +++++++++++++- drivers/clk/clk-gpio.c | 50 ++++++++++++++++++++-- 2 files changed, 77 insertions(+), 5 deletions(-) --- base-commit: fd179f8a05be3ccae366b9b96e176b51fbe54aab change-id: 20260318-feature-clock-guard-f20a2c35b965 Best regards, -- Vyacheslav Yurkov