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 5A47C30F55E; Mon, 17 Nov 2025 07:38:53 +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=1763365133; cv=none; b=SiXqpxENqOSMBxUL6XEScLIl0L6dNUdVK0nE3RY61LSBhhN66IcogMPQhULgQ4sFxmasw5LDGGPwcTlRpb8G6l/rUBSvO8tOyKoUL2FYcrdI1QEqhJEkqia9dnZix/MkK1/Cx0u+PcAfeDoA8uhoVy7ps9iauTHjRK7mEmRRxzU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763365133; c=relaxed/simple; bh=JH4JaDRYvV5msbcyMy/ghQDyrY39sdXyPDGMLdLPPwY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=toOgbjDWPmTLprL3HayaTjV1JgviMT6qJpS7DvfHMsEhboYjz8QB2GpFk9ep5WG5fquTqehnU4sX4RgS6w9g5LNSYGSye/ArPJzfsEvdk8UPmbqCFsYdijzg8VVg6e42GUFHY6BSBAXpJYjeVMBZqFBWEhS9oTz9RKsWW6PxMqA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Uu5O2GEZ; 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="Uu5O2GEZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9EE45C19424; Mon, 17 Nov 2025 07:38:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763365132; bh=JH4JaDRYvV5msbcyMy/ghQDyrY39sdXyPDGMLdLPPwY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Uu5O2GEZW8AllFKpmVgxbvfBjzqFNfeC9yR+iT3ee96jITUefaCHDBuQf255aLm6C zl6R46zOTfsEW7yALjVWhZreFEkNuqrDqSzy/rHjG3iDBjcafrdxgoU/sVTxf2VQt+ 19EfHvka0ves2jaCtdVaffI8Qb7x9OJX8w+OdFbRenbyD2mY0T8K2rF8AiaC6nz50p 4l4hSEVqZ9iPcpHnCpNo5iTuUTNMF8GNH8V3bmvtY6sRnUUK8HgluKBj0yG/K3j5VR bnT1JGLc1BvCULuTmx4CZUz7HLazhMB1XzxLO174lSNN21EXvi4QJZrs3aVNKYzkWm sU3J7eAyMhKDQ== Message-ID: <58816b68-3b09-4320-9a4e-09f2c2b2d0fa@kernel.org> Date: Mon, 17 Nov 2025 08:38:48 +0100 Precedence: bulk X-Mailing-List: devicetree-spec@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: SoC-specific device tree aliases? To: Ahmad Fatoum , "devicetree@vger.kernel.org" , Rob Herring , Krzysztof Kozlowski , Conor Dooley , devicetree-spec@vger.kernel.org Cc: "kernel@pengutronix.de" , quentin.schulz@cherry.de References: From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGVBBMBCgA/AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJoF1BKBQkWlnSaAAoJEBuTQ307 QWKbHukP/3t4tRp/bvDnxJfmNdNVn0gv9ep3L39IntPalBFwRKytqeQkzAju0whYWg+R/rwp +r2I1Fzwt7+PTjsnMFlh1AZxGDmP5MFkzVsMnfX1lGiXhYSOMP97XL6R1QSXxaWOpGNCDaUl ajorB0lJDcC0q3xAdwzRConxYVhlgmTrRiD8oLlSCD5baEAt5Zw17UTNDnDGmZQKR0fqLpWy 786Lm5OScb7DjEgcA2PRm17st4UQ1kF0rQHokVaotxRM74PPDB8bCsunlghJl1DRK9s1aSuN hL1Pv9VD8b4dFNvCo7b4hfAANPU67W40AaaGZ3UAfmw+1MYyo4QuAZGKzaP2ukbdCD/DYnqi tJy88XqWtyb4UQWKNoQqGKzlYXdKsldYqrLHGoMvj1UN9XcRtXHST/IaLn72o7j7/h/Ac5EL 8lSUVIG4TYn59NyxxAXa07Wi6zjVL1U11fTnFmE29ALYQEXKBI3KUO1A3p4sQWzU7uRmbuxn naUmm8RbpMcOfa9JjlXCLmQ5IP7Rr5tYZUCkZz08LIfF8UMXwH7OOEX87Y++EkAB+pzKZNNd hwoXulTAgjSy+OiaLtuCys9VdXLZ3Zy314azaCU3BoWgaMV0eAW/+gprWMXQM1lrlzvwlD/k whyy9wGf0AEPpLssLVt9VVxNjo6BIkt6d1pMg6mHsUEVzsFNBFVDXDQBEADNkrQYSREUL4D3 Gws46JEoZ9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLue MNsWLJBvBaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6ei OMheesVS5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wA GldWsRxbf3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA 6z6lBZn0WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9 YegxWKvXXHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt 91pFzBSOIpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gU BLHFTg2hYnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/ JoFzZ4B0p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu 4vXVFBYIGmpyNPYzRm0QPwARAQABwsF8BBgBCgAmAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtB YpsFAmgXUF8FCRaWWyoACgkQG5NDfTtBYptO0w//dlXJs5/42hAXKsk+PDg3wyEFb4NpyA1v qmx7SfAzk9Hf6lWwU1O6AbqNMbh6PjEwadKUk1m04S7EjdQLsj/MBSgoQtCT3MDmWUUtHZd5 RYIPnPq3WVB47GtuO6/u375tsxhtf7vt95QSYJwCB+ZUgo4T+FV4hquZ4AsRkbgavtIzQisg Dgv76tnEv3YHV8Jn9mi/Bu0FURF+5kpdMfgo1sq6RXNQ//TVf8yFgRtTUdXxW/qHjlYURrm2 H4kutobVEIxiyu6m05q3e9eZB/TaMMNVORx+1kM3j7f0rwtEYUFzY1ygQfpcMDPl7pRYoJjB dSsm0ZuzDaCwaxg2t8hqQJBzJCezTOIkjHUsWAK+tEbU4Z4SnNpCyM3fBqsgYdJxjyC/tWVT AQ18NRLtPw7tK1rdcwCl0GFQHwSwk5pDpz1NH40e6lU+NcXSeiqkDDRkHlftKPV/dV+lQXiu jWt87ecuHlpL3uuQ0ZZNWqHgZoQLXoqC2ZV5KrtKWb/jyiFX/sxSrodALf0zf+tfHv0FZWT2 zHjUqd0t4njD/UOsuIMOQn4Ig0SdivYPfZukb5cdasKJukG1NOpbW7yRNivaCnfZz6dTawXw XRIV/KDsHQiyVxKvN73bThKhONkcX2LWuD928tAR6XMM2G5ovxLe09vuOzzfTWQDsm++9UKF a/A= In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 13/11/2025 09:28, Ahmad Fatoum wrote: > Hello, > > With /chosen/bootsource now part of dt-schema, I would like to raise a > related point: The need for SoC-specific device tree aliases. > > For many SoCs, there is a canonical numbering for peripherals; it's used > in the datasheet and BootROMs often makes use of it at runtime to report > the bootsource as a pair: > > - One value to enumerate type of boot medium (e.g. mmc, spi-nor..) > - Another value that describes which instance (e.g. SDHC1, SPI3, ...) > > Some examples, where this is the case, are AT91, STM32MP or i.MX. > > barebox has traditionally used /aliases to translate BootROM information > to a device tree node to fixup /chosen/bootsource. > > This doesn't work out for many newer SoC support, because of different > expectations: For upstream, aliases are relevant to a board, while > barebox traditionally expected them to be SoC-specific (because they > used to be on i.MX, probably). Please state exactly the problem - you have aliases in DTS but bootsource in DTSI? Then that's clearly mixup - you need to define them in the same place. Aliases are in DTS (I see here other thread on that), so stdout-path is also in DTS. Or you don't have bootsource in DTSI at all because barebox invents it regardless of actual aliases? Then shouldn't this be an obvious issue? You cannot have barebox as second source of aliases. > > To accommodate this, barebox nowadays extends upstream device trees with > /chosen/barebox,bootsource-${alias} properties, which can be used as > translation table instead of aliases. > > This solves the issue, but there is occasional breakage when upstream > decides to remove aliases from the SoC DTSI and move them into the > boards until barebox is made to add the /chosen/barebox, overrides. > > As described above, I think the data sheet numbering is pretty much an > aspect of the hardware and it has a place in the upstream SoC DTSI. > > > So what are the thoughts on adding /soc/aliases or some other top-level > node to hold this information? > Or would a h"ardware-label" property or similar be more tenable? So you want to map full node path to some alias, so later you can map that alias back to full node path, right? This sounds like quite redundant information in DTS just to avoid impact of node reshuffling (like unit address changes). In DTS-source-code realm, we solved it with phandles. Maybe this would help here? Best regards, Krzysztof