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 2A781478E25; Tue, 15 Sep 2026 09:27:48 +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=1789464469; cv=none; b=EDUIz+dimms1zjOk1b4E7GyGYc0dAx/9uAmF7bNyJjF74X+d2GMJMVj8w0KgaNV+/ao0gs3WS2JzBLkcpsmL9RvW10NgYWeSSeRsHCSNheSF8eWtcsSxYRfj4pro66pHW1PAfgMCG8n1MhIJ6NlKuzb2CVV26SiVE3yzqWNsw1g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789464469; c=relaxed/simple; bh=pHHLU5mEhTrcsZXkgtfWaWrdA6AqMjp+/cG3jZ+76cM=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=c5o8dirKFM2tEeUY+c0NGU146c/NGsxhwGDmXtASEdaVDsxGeBy8GGKpThdlS30HKXoimLOWZ04djWZ5r9bBp8/m27zgoIz/mddM+NrbkSxaibA82S2JtD+aP8hID3RuJBSlg0kDJcpU1smZreCcZyfoVqJ7VOmt8wAaIISbi18= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MKdDZnCp; 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="MKdDZnCp" Received: by smtp.kernel.org (Postfix) with ESMTPS id AAC30C2BCB8; Tue, 15 Sep 2026 09:27:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1789464468; bh=pHHLU5mEhTrcsZXkgtfWaWrdA6AqMjp+/cG3jZ+76cM=; h=From:Subject:Date:To:Cc:Reply-To:From; b=MKdDZnCpfW4MTW0ilhNtfuZgyyafxinkK3j3XlfdUK1qi1n9lsiz1R9Sg0td4OZ5O C43RbvI1FHmETt0Ow6qHOxwdBAEr+zwSgZv9cQaAa+sXhRCAs1FfCAeiyqHc8IBBW5 zDcu9y+pm4E0NiONOnfcA52C3e94H8m8vH1Nj/bLFGxnwiErECKXPkzONSEUesA3ej 97FdHLsGRGwuv40g1HBO4lnUEZ86RndzV4vMwVq6BPAMuUQsTRVdXSqld8pAow6oHi t0mp71mW0UuOka5drVt/Z8iQj9xR3Q+4pPFcRY5LCeVCejKYcDLds++ok1Q+mFDYL4 Nzp4ner0u84GA== 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 866F6C88E75; Tue, 15 Sep 2026 09:27:48 +0000 (UTC) From: Vyacheslav Yurkov via B4 Relay Subject: [PATCH v5 0/2] A proposal to add a gpio-locked fixed clock driver. Date: Tue, 15 Sep 2026 09:27:38 +0000 Message-Id: <20260915-feature-clock-guard-v5-0-42ab5dc3a6aa@bruker.com> Precedence: bulk X-Mailing-List: linux-clk@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=H4sIAIoPqWoC/33OzQrCMAzA8VeRnq2kabtOT76HeGizTIsfk84NR fbudl6GODz+A/klL9FyityKzeIlEvexjc01h10uBB399cAyVrkFAhagVSlr9vcusaRzQyd56Hy qZI3gkbQN68KKvHlLXMfHR93tcx9je2/S83OkV+P0v9crCbJQ2lEwUJrgtiF1J04rai5iBHucE KtgHsERIbTGlpXVBn4QPSH5l3lEZwQUkQfvwXj7g5gJcVjMIyYjvKYyaIfBKfpChmF4A+BtX06 GAQAA 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=1789464467; l=2482; i=V.Yurkov.EXT@bruker.com; s=20260318; h=from:subject:message-id; bh=pHHLU5mEhTrcsZXkgtfWaWrdA6AqMjp+/cG3jZ+76cM=; b=V/uF4f5MjmuHdY7wLqc7A7A/h8M21hHv7OddW2uff3EnCqLHK/HtcjsaPRelROgCAKomQ7Otd 83Tsh0nBuWcAqf25ZO4MnsL9C5OCVNEgb3X50qo4VX4IAM7oURwBeje 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 fixed 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 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 fixed clock driver .../devicetree/bindings/clock/gpio-gate-clock.yaml | 32 +++- drivers/clk/Makefile | 1 + drivers/clk/clk-gpio-locked.c | 169 +++++++++++++++++++++ 3 files changed, 200 insertions(+), 2 deletions(-) --- base-commit: 704340f1cd0dcef829eb62f5b48ae95a2ce17bdf change-id: 20260318-feature-clock-guard-f20a2c35b965 Best regards, -- Vyacheslav Yurkov