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 11C843AEF4F; Thu, 14 May 2026 12:12:07 +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=1778760728; cv=none; b=cZqUcWYmzJKHWXmuaONPQekEqm8M7pyHi63qP7Wm/PGyxMhsGBerP8jF7ThgWu0dU97SFtNBRjr56FvP37R+aGnNdIMf/b2nJBL4C4QqVq4kiKWc9Uq47C2Ztkmpl6GeTH4HGlV8aU3rT9RYbKRb/JEQIcz0nhxy5azOX9I4Uus= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778760728; c=relaxed/simple; bh=5iwiGUataS3Aet0+bjaNI17LShBzXko8CYOfIv+JMyE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BOTgde9HTcemKmV3ljt2JO76G9eKyG1B3hL76HgjVw68A+AzcVaqrthea3QmBE5vaOKnbbaymfSvKEifLc+y3j+knL53Npvk6FfBBt4XsZY1VM/SmwG6iREqY8T38+SK0kDRJQ3vY/c0+NINGkFJxjMslsDG7P9Z/I5R6XXIpV4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OhrkRwEI; 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="OhrkRwEI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2281CC2BCB8; Thu, 14 May 2026 12:12:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778760727; bh=5iwiGUataS3Aet0+bjaNI17LShBzXko8CYOfIv+JMyE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OhrkRwEIKGVxHnNOX1IpNj3lYjD3G5R9c/M4IKBnRs9SXIa3yimiBl4Usy9CkmLIE eIK4yLNCxe8Y3zq2WA1OE2+7R/LjmgbFGAs+FBJsS16WIbF2+b9S9bNYqVltl9ZPdB sZi5cfI51dNYc43hmBfP+9S/PU+VjZy/fGDt2byt0cUj85Aezsx9E8ffn9xPPBW/jT j5ewbNOIOxM1au2c6BvOH92j34X5yejU/rhNyfgY6cV4heLnaR/FZaGcRj0g5f0/GB Us+LDjfssekZ+d0wHABJEDjndbeQx3pNQL23VsMTnsFceyBj0e5sex891rVLYO/G6H cRzVl1pxkfRog== Date: Thu, 14 May 2026 14:12:05 +0200 From: Krzysztof Kozlowski To: Vyacheslav Yurkov Cc: Michael Turquette , Stephen Boyd , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, Vyacheslav Yurkov Subject: Re: [PATCH v2 0/2] A proposal to add a gpio-locked fixed clock driver. Message-ID: <20260514-stylish-naughty-orca-bfbf80@quoll> References: <20260510-feature-clock-guard-v2-0-6c25458d5340@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-Disposition: inline In-Reply-To: <20260510-feature-clock-guard-v2-0-6c25458d5340@bruker.com> On Sun, May 10, 2026 at 06:06:21PM +0000, Vyacheslav Yurkov wrote: > A gpio-locked fixed clock aggregates one or more input clocks and/or one > or more GPIOs. 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 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 > > --- Please format your submission properly - read DT bindings submitting patches, add proper blank lines in the schema, use generic node names so that we can avoid commenting trivialities. Best regards, Krzysztof