From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 43FC63B27DB; Wed, 18 Mar 2026 16:01:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773849671; cv=none; b=TJxPSTKE4ws+M19F1SZLl3p0/bNbSBLgKDIGdbOtbqBo9kKmNwpO1ROF9AsCRqoz/ROC5J3fQQvM3SFCx+/BoYiIF2YtoaEr9msbRn5+AjaTbiaCWNH5UaYNAz7nE4wXAvtj5pztLAkF6vw0RU9qXl1AEPGRI+/mUPGS8WOVPGU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773849671; c=relaxed/simple; bh=9lbXZPvYtJTGMGIkIWrytsOtkrhzDdxlxU1ozegV1Ao=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=iGgRBq4vzZYhBdmvpw+IxvBPOwzjT16TTZi25vOO6e2X1wLQvOmc8U18lJFCRVEBDIWpHp41k9s0b1WfPuVk5VIVOC5nb3iN//4dr7F073Sis2FF78n67KrUJZYPPg0US76TPkfnNsfYsBeL8b0oW55K+Mwxv5AhoGoDvHbEEPk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 75B7D1A25; Wed, 18 Mar 2026 09:00:58 -0700 (PDT) Received: from [192.168.178.23] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F200B3F73B; Wed, 18 Mar 2026 09:01:00 -0700 (PDT) Message-ID: <73a2e7fa-ab30-4d81-a4ff-0292b6adf346@arm.com> Date: Wed, 18 Mar 2026 17:00:13 +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 v2 1/8] dt-bindings: arm: Add Live Firmware Activation binding To: Krzysztof Kozlowski Cc: Mark Rutland , Lorenzo Pieralisi , Sudeep Holla , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Salman Nabi , Vedashree Vidwans , Trilok Soni , Nirmoy Das , vsethi@nvidia.com, vwadekar@nvidia.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org References: <20260317103336.1273582-1-andre.przywara@arm.com> <20260317103336.1273582-2-andre.przywara@arm.com> <20260318-inventive-tortoise-of-romance-c7ceba@quoll> Content-Language: en-US From: Andre Przywara In-Reply-To: <20260318-inventive-tortoise-of-romance-c7ceba@quoll> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi, On 3/18/26 09:04, Krzysztof Kozlowski wrote: > On Tue, Mar 17, 2026 at 11:33:27AM +0100, Andre Przywara wrote: >> The Arm Live Firmware Activation spec [1] describes updating firmware > > A nit, subject: drop second/last, redundant "binding". The > "dt-bindings" prefix is already stating that these are bindings. > See also: > https://elixir.bootlin.com/linux/v6.17-rc3/source/Documentation/devicetree/bindings/submitting-patches.rst#L18 Sure, will fix. >> images during runtime, without requiring a reboot. Update images might >> be deployed out-of-band, for instance via a BMC, in this case the OS >> needs to be notified about the availability of a new image. >> >> This binding describes an interrupt that could be triggered by the > > Describe hardware/firmware, not the binding. Right, sorry, this slipped through. >> platform, to notify about any changes. >> >> [1] https://developer.arm.com/documentation/den0147/latest/ >> >> Signed-off-by: Andre Przywara >> --- >> .../devicetree/bindings/arm/arm,lfa.yaml | 45 +++++++++++++++++++ >> 1 file changed, 45 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/arm/arm,lfa.yaml >> >> diff --git a/Documentation/devicetree/bindings/arm/arm,lfa.yaml b/Documentation/devicetree/bindings/arm/arm,lfa.yaml >> new file mode 100644 >> index 000000000000..92f0564fd672 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/arm/arm,lfa.yaml >> @@ -0,0 +1,45 @@ >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >> +%YAML 1.2 >> +--- >> +$id: http://devicetree.org/schemas/arm/arm,lfa.yaml# >> +$schema: http://devicetree.org/meta-schemas/core.yaml# >> + >> +title: Arm Live Firmware Activation (LFA) >> + >> +maintainers: >> + - Andre Przywara >> + - Sudeep Holla >> + >> +description: >> + The Arm Live Firmware Activation (LFA) specification [1] describes a >> + firmware interface to activate an updated firmware at runtime, without >> + requiring a reboot. Updates might be supplied out-of-band, for instance >> + via a BMC, in which case the platform needs to notify an OS about pending >> + image updates. >> + [1] https://developer.arm.com/documentation/den0147/latest/ >> + >> +properties: >> + compatible: >> + const: arm,lfa > > Does specification has a version? Does it support version discovery? Yes and yes. there is a mandatory LFA_GET_VERSION call, with major and minor version. And please note that the discovery of the firmware functionality doesn't rely on DT (or ACPI) at all - it uses discoverable SMCCC calls instead. We just need this DT node to convey the (optional) platform specific interrupt number. >> + >> + interrupts: >> + maxItems: 1 >> + description: notification interrupt for changed firmware image status >> + >> +required: >> + - compatible >> + - interrupts >> + >> +additionalProperties: false >> + >> +examples: >> + - | >> + #include >> + >> + firmware { >> + arm-lfa { > > Node names should be generic. See also an explanation and list of > examples (not exhaustive) in DT specification: > https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation > If you cannot find a name matching your device, please check in kernel > sources for similar cases or you can grow the spec (via pull request to > DT spec repo). > > arm-lfa is specific, so this could be as "fota" or "firmware-update" OK, will try to come up with a good name. Thanks for the review! Cheers, Andre > > Best regards, > Krzysztof >