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 BA17C7175A; Thu, 14 Mar 2024 15:20:30 +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=1710429632; cv=none; b=bLugoA9rpjJPHNpUvoaDV3nfO8IhLYhuM5QD2Aff86Rj2SPy43K8a20jUKFBVvMRMlJWGRjeeQA7Wl6RYQ+eRtFUxZMUrGGYClx3WU/5hyNssqJoKMbeHl6NnkMme1QFGYDM5ifEDGOL/h3OrD3hv8M0TQc604tz8wNA5R2khBs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710429632; c=relaxed/simple; bh=dcb/gsF85aoiYODQ+GAmVe2LLHQNrA+u7u1lvW9BxAw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TnGdypv3L/TmI/c/oPGNzxdCWw6gFvmviFUhMbXSEQsO+HNlyD/FV2Ol1Y5sstbHoPDJvrJmYLvsbnVnGCdIdTpl93F2VUK5LiYeAKwOSGnT/J1duwhQ6BhDQAq3ZkA55xgyvJlCJ9HXHZwCSmzEQA9QYxHIQzpCXJp5To34GdE= 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 43CEF1007; Thu, 14 Mar 2024 08:21:06 -0700 (PDT) Received: from e130802.arm.com (e130802.arm.com [10.1.33.51]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AE0AE3F762; Thu, 14 Mar 2024 08:20:26 -0700 (PDT) Date: Thu, 14 Mar 2024 15:20:18 +0000 From: Abdellatif El Khlifi To: Krzysztof Kozlowski Cc: Robin Murphy , Bjorn Andersson , Mathieu Poirier , Rob Herring , Liviu Dudau , Sudeep Holla , Lorenzo Pieralisi , Krzysztof Kozlowski , Conor Dooley , Drew.Reed@arm.com, Adam.Johnston@arm.com, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-remoteproc@vger.kernel.org Subject: Re: [PATCH 3/3] dt-bindings: remoteproc: Add Arm remoteproc Message-ID: <20240314152018.GA41711@e130802.arm.com> References: <20240301164227.339208-1-abdellatif.elkhlifi@arm.com> <20240301164227.339208-4-abdellatif.elkhlifi@arm.com> <8c784016-9257-4d8a-b956-a0a406746c76@arm.com> <20240314134928.GA27077@e130802.arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Hi Krzysztof, On Thu, Mar 14, 2024 at 02:56:53PM +0100, Krzysztof Kozlowski wrote: > On 14/03/2024 14:49, Abdellatif El Khlifi wrote: > >> Frankly at the moment I'd be inclined to say it isn't even a remoteproc > >> binding (or driver) at all, it's a reset controller. Bindings are a contract > >> for describing the hardware, not the current state of Linux driver support - > >> if this thing still needs mailboxes, shared memory, a reset vector register, > >> or whatever else to actually be useful, those should be in the binding from > >> day 1 so that a) people can write and deploy correct DTs now, such that > >> functionality becomes available on their systems as soon as driver support > >> catches up, and b) the community has any hope of being able to review > >> whether the binding is appropriately designed and specified for the purpose > >> it intends to serve. > > > > This is an initial patchset for allowing to turn on and off the remote processor. > > The FW is already loaded before the Corstone-1000 SoC is powered on and this > > is done through the FPGA board bootloader in case of the FPGA target. > > Or by the Corstone-1000 FVP model (emulator). > > > > The plan for the driver is as follows: > > > > Step 1: provide a foundation driver capable of turning the core on/off > > Step 2: provide mailbox support for comms > > Step 3: provide FW reload capability > > > > Steps 2 & 3 are waiting for a HW update so the Cortex-A35 (running Linux) can > > share memory with the remote core. > > > > So, when memory sharing becomes available in the FPGA and FVP the > > DT binding will be upgraded with: > > > > - mboxes property specifying the RX/TX mailboxes (based on MHU v2) > > - memory-region property describing the virtio vrings > > > > Currently the mailbox controller does exist in the HW but is not > > usable via virtio (no memory sharing available). > > > > Do you recommend I add the mboxes property even currently we can't do the comms ? > > Bindings should be complete, regardless whether Linux driver supports it > or not. Please see writing bindings document for explanation on this and > other rules. > > So yes: please describe as much as possible/reasonable. I'll do thanks. Cheers, Abdellatif