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 C032C2DC783; Tue, 21 Apr 2026 08:46:59 +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=1776761219; cv=none; b=d0sti2ODVksXIGP6jyNBl8mLxMc3aO1erY1ehcG6nCqMbu3NIX0C4H0yRnGZGdY1JxGWk1/qmYmCakDPCREA8RLHTYa2K/uprlDS5zylZ1A3T10Hoqx8cb/6Fj1YHLum9FK79lKWPrZJouNn7u7aMDq5afei+i4WUy/3UFrB9ms= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776761219; c=relaxed/simple; bh=P2sLB2zT3iVQj9YGkWcLvciVcbDcFv3aDchjxcINyac=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=E9U7G4j+watxxHdBSGyIQ5fEDwb+cR54GigmbBP69PKzDZRHx6D6yIh1xj0KLvNHdlahv5iZlo0KCcOUWIFquU/YC30QRIARY2wIeThlGt/b024ZFx9jVppdFlo1xf8ubyB+u4gaXmZhP9WafctD2vm7mmGiP+kOwiiEUm7F4V4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rDzvRz7A; 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="rDzvRz7A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B802C2BCB0; Tue, 21 Apr 2026 08:46:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776761219; bh=P2sLB2zT3iVQj9YGkWcLvciVcbDcFv3aDchjxcINyac=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=rDzvRz7AfjXRGiU9f3gXMmOxNa0qk8ii3PC9+yGieLom9iOlOd9RDAWdsnOyibC3y jMAWupELQdDjZNNCfhXkxWMHLTrKEZVyQ90DSEnb8lzYO+hGSkCv2RHXNpVybFUMML qyktilv8tZ8YEV3Q0fMmx2wsgyu5YLfYRf8yGfGiK/F4dzFwRmU+wy8w+KcaezcJr6 O8rqRSDom478LZs284MP/td6yXsumoQkuRJKaDjkjO29gB/hpu1HLruXbqQ/ZH/Pdx V//p7mBz5sCHSqQNvPC71GiyYG96zrgfzBvvOMnDxEshjovnvUfZKdMbnaStMfchuB 55DQPhfg8etVw== Message-ID: Date: Tue, 21 Apr 2026 10:46:55 +0200 Precedence: bulk X-Mailing-List: linux-spi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 1/2] dt-bindings: trivial-devices: add toradex,lava-hat-spi To: Francesco Dolcini Cc: Conor Dooley , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Mark Brown , Francesco Dolcini , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org References: <20260420114537.78160-1-francesco@dolcini.it> <20260420114537.78160-2-francesco@dolcini.it> <20260420-task-navy-370ea247fe1d@spud> <005d96ea-b250-4af8-9c5b-d145bae892e5@kernel.org> <20260421083843.GA23508@francesco-nb> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 21/04/2026 10:38, Francesco Dolcini wrote: > On Mon, Apr 20, 2026 at 06:10:08PM +0200, Krzysztof Kozlowski wrote: >> On 20/04/2026 18:02, Conor Dooley wrote: >>> On Mon, Apr 20, 2026 at 01:45:35PM +0200, Francesco Dolcini wrote: >>>> From: Francesco Dolcini >>>> >>>> Add a compatible string for the SPI loopback device present on the >>>> Toradex LAVA HAT test fixture. >>>> >>>> The Toradex LAVA HAT is a board used for automated hardware-in-the-loop >>>> (HIL) testing, it provides several test-related functionalities, and >>>> exists in multiple variants depending on the board it is mated with. The >>>> SPI function is implemented with a loopback on the MISO/MOSI signals. >>>> >>>> As the device can be fully described using only "compatible" and "reg", >>>> it is appropriate to list it under trivial-devices.yaml rather than >>>> introducing a dedicated binding. >>>> >>>> The SPI implementation is identical across all Toradex LAVA HAT >>>> variants, so a single compatible string is sufficient. >>>> >>>> Link: https://lore.kernel.org/all/20260310133254.GA51497@francesco-nb/ >>>> Link: https://lore.kernel.org/all/20260316073547.11437-3-francesco@dolcini.it/ >>>> Signed-off-by: Francesco Dolcini >>> >>> Acked-by: Conor Dooley >>> pw-bot: not-applicable >> >> >> Heh, let's wait. That's a test device, so it won't be ever used in any >> final product, right? So not in final DTS? > > It will be used in various DT overlay, that I plan to send for > inclusion in mainline Linux kernel once we have a way forward. So yes, > there will be DTB files using it. Then you need to document it properly and post the DTS. Toradex LAVA hat is way too generic. No, single compatible string is not sufficient, please read writing bindings. Please define exact model and variants. > > The need is to be able to test SPI with a mainline Linux kernel, so I am > looking for a solution that works in mainline Linux. incomplete devices do not stop you from that. But you don't get exceptions because you want to mainline your DTS. Your need detailed hardware description and precise compatible per each exact hat ("exists in multiple variants"). Best regards, Krzysztof