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 02E6929A32D; Thu, 26 Mar 2026 13:49:58 +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=1774532999; cv=none; b=simChH78HnYT9q1J7fPyKfXtW3OE62c9IL+IuXi9U8ocTxhgyJCzM31VGvxrOzk/5snMEXCncQ9bp6JPWydJvGaWxHRhDS+YGUwj/BRrjE9AdY86KcRKKLWAhl3vYdvZiLWFdWvmbFfyifrb0gEczsqnD2bvRsm7ry9IsxRl38w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774532999; c=relaxed/simple; bh=x+fkM6vu5h7RY1/dOIAEf+g4E+vu6Ey+LIqxNEADWHo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fwfbc8gUuje3Yfwe/pjUVl+o9d/SkfnBjV/42BTFrje4vmXNWREEVfqoRnp5C77eRk7cwsMz+iPaDBQjs2FDTEwQDlGgns/QNHqPoCbaYjTHa0J1cKGwwAutOsxzyLvvK6UeIfMMMZAZjp4kUwmVEebdSGRLAwMNFQMdkkGwoiM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KrHV1CTn; 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="KrHV1CTn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C9DEC116C6; Thu, 26 Mar 2026 13:49:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774532998; bh=x+fkM6vu5h7RY1/dOIAEf+g4E+vu6Ey+LIqxNEADWHo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=KrHV1CTnkTzSlumk1EEyxUu+GRLJnu+FL95+kGj/yh0MC3EMjWf1+XB/HMzf7I9RG Y5D+K7uO0JZjV9+bzASroCdyKyz7PCY4wswtiFu6dkiFSK82pDcBfEgjypEOMOeQbJ Mxp9Y21UXiA+i+PZ3If+3QesNlg8JehOOToMmJy5nJtF6HdPsIMN/ceZxEsFZCVbS6 JW/km02lHPcd2mkBylT3szbC87lg93oei+pnpgOYNqV9/Wt3ihE5GCp2NjN6hARF2/ yHdlaMH/n1o05XSd/zkmB/NivUVf7sxLWscU01YiPA4GV5oMuK7KudVWZFDEfopcCD RMhH+8494LkJA== Message-ID: Date: Thu, 26 Mar 2026 14:49:54 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] dt-bindings: Add clock guard DT description To: Vyacheslav Yurkov , Conor Dooley Cc: Rob Herring , Vyacheslav Yurkov , Michael Turquette , Stephen Boyd , Krzysztof Kozlowski , Conor Dooley , linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org References: <20260318-feature-clock-guard-v1-0-6137cb4084b7@bruker.com> <20260318-feature-clock-guard-v1-2-6137cb4084b7@bruker.com> <20260318225510.GA639444-robh@kernel.org> <7c7034a7-686a-42c2-bdba-6f31b5179f7c@gmail.com> <20260319-yearly-wrongful-883f7fd86a69@spud> <20260323-sanctuary-semantic-432089feb1c7@spud> <8e7d0c53-aa23-4514-81a5-335a76bb0c45@kernel.org> <4d575f17-5cd5-495c-99a9-176b3393d54d@gmail.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 26/03/2026 14:39, Vyacheslav Yurkov wrote: > On 26.03.2026 11:08, Krzysztof Kozlowski wrote: > >>> >>> DTS example: >>> clock_guard: clock_controller_guard { >>> compatible = "clock-controller-guard"; >>> #clock-cells = <1>; >>> clocks = <&h2f_clk 0>, <&clk_fgpa_rx 0>, ; >>> clock-names = "h2f_clk0", "clk_fpga_rx", "clk_fpga_tx"; >>> gpios = <&fpga_ip 0 GPIO_ACTIVE_HIGH>, <&fpga_ip 1 GPIO_ACTIVE_HIGH>; >>> gpio-names = "gpio-input0", "gpio-input1"; >>> clock-output-names = "clkctrl-guard"; >>> }; >>> >>> custom_device { >>> compatible = "..."; >>> ... >>> #clock-cells = <1>; >>> clocks = <&clock_guard 0>; >>> clock-names = "clock-guard"; >>> }; >> >> So a pure SW construct? Device has specific clock inputs but you do not >> model them and instead replace with one fake-guard-input. >> >> I don't see how this represents the hardware at all. >> >> Maybe some diagrams would help, assuming we still talk about hardware. >> >> Best regards, >> Krzysztof > > Techincally that's correct, it's a software construct. If this is not a > right place to submit such a helper driver, I'd appreciate a hint what > subsystem is the right one. > > I was not sure how to provide a diagram in the mailing list, so I posted > in on Github https://github.com/OSS-Keepers/clock-controller-guard/issues/1 Diagram of hardware. We talk here about hardware. > > It is a driver which models dependencies for other drivers. These are > soft or "indirect" dependencies, because we cannot access the FPGA > unless the FPGA_PLL_locked, and GPIO is telling us we are good to go. DT is not for drivers. It's not about subsystem, but concept. DT describes hardware. Certain generic bindings which solve real and common hardware problems are accepted, but so far I miss what hardware problem are you solving here. Best regards, Krzysztof