From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from codeconstruct.com.au (pi.codeconstruct.com.au [203.29.241.158]) (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 4AF0E10F1; Thu, 17 Oct 2024 00:08:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.29.241.158 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729123715; cv=none; b=JovLLILVZOaEkTB5Y6hXarQSaPifnCgF8/0J5bh+70t3sPFSUgSk7vgD04M8eWlYhWTEUd1aBQMJobdSntqbPSXtmMZwe6r3xoqbx13NR2SFOXp7fwP3GdC/sj9gvnx32xGmziHOVZfS7en1oSM9MCENMm2EQhJd6LaPgKCAi+g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729123715; c=relaxed/simple; bh=MJLV0tcHDxYrAJWRYnY4HRU2T9JXBQ/Ox19qpn6RCQY=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=ZvLUJq/WuqnqmV/kyemB53FGOyEefv0ZSocbeqpb8FOcexYwD2+dxEa2fcSM5R2Ni5Q7Y7JeRZGDwhm++ysBdnawGBTvcSXHIq7wwb9A19hXjNUpq06SsRj6NdD/41gSF9DgosuiQSzsfdA8pivaN5fDFmN9ICMBVqHNSJwTY08= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=codeconstruct.com.au; spf=pass smtp.mailfrom=codeconstruct.com.au; dkim=pass (2048-bit key) header.d=codeconstruct.com.au header.i=@codeconstruct.com.au header.b=PdIzXG2o; arc=none smtp.client-ip=203.29.241.158 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=codeconstruct.com.au Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=codeconstruct.com.au Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=codeconstruct.com.au header.i=@codeconstruct.com.au header.b="PdIzXG2o" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codeconstruct.com.au; s=2022a; t=1729123710; bh=MJLV0tcHDxYrAJWRYnY4HRU2T9JXBQ/Ox19qpn6RCQY=; h=Subject:From:To:Cc:Date:In-Reply-To:References; b=PdIzXG2oo8nlIjIt6YdEvK79moJ6OhTLC/559NkVkW3MmTY58QSR7gPQ2bMIHvFPP K0jYXX6ycnnuKPOQrAUJeXy6ScnODBUZNqR8dMda4SDR9uglT/iFxny9G3M41bYOpc X7Ic9ngP3FWtxLnyhAK29dxGRG5XcISMN1L4Z51H2nZ7c+G9tMRMhgP+PiM+VV1XoA 20HeD6o6Hikr84Z4Pr2tfKanhrxUbO7LT03hNeSt9ClkUIvB+6moOuJTHcQga5u3As 5+Ucba5h9Cw30ZS3/6cwBRcxAKBVgYE/y6HDHu0vkmhsf06bI+PO56Qx1DJUrSQWhW Cet5g3j+8MMbA== Received: from [192.168.68.112] (203-173-0-39.dyn.iinet.net.au [203.173.0.39]) by mail.codeconstruct.com.au (Postfix) with ESMTPSA id 913C667E1F; Thu, 17 Oct 2024 08:08:27 +0800 (AWST) Message-ID: Subject: Re: [PATCH] ARM: dts: aspeed: Add device tree for Ampere's Mt. Jefferson BMC From: Andrew Jeffery To: Chanh Nguyen , Chanh Nguyen Cc: "Rob Herring (Arm)" , Joel Stanley , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Khanh Pham , linux-arm-kernel@lists.infradead.org, Thang Nguyen , Krzysztof Kozlowski , Phong Vo , Conor Dooley , Rob Herring , OpenBMC Maillist , Open Source Submission , Quan Nguyen , linux-aspeed@lists.ozlabs.org Date: Thu, 17 Oct 2024 10:38:26 +1030 In-Reply-To: References: <20241014105031.1963079-1-chanh@os.amperecomputing.com> <172891445289.1127319.4114892374425336022.robh@kernel.org> <7555c528c90e6151f54d0e17c278527f95fac184.camel@codeconstruct.com.au> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.46.4-2 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Hi Chanh, On Wed, 2024-10-16 at 17:26 +0700, Chanh Nguyen wrote: >=20 > On 16/10/2024 12:07, Andrew Jeffery wrote: > > You can also find discussions where other maintainers (Guenter, hwmon > > maintainer; Krzysztof, devicetree maintainer) have asked that "pmbus" > > not be used as a compatible: > >=20 > > https://lore.kernel.org/all/f76798ea-6edd-4888-8057-c09aaed88f25@roeck-= us.net/ > >=20 >=20 > Hi Andrew, > I checked the discussion at=20 > https://lore.kernel.org/all/f76798ea-6edd-4888-8057-c09aaed88f25@roeck-us= .net/=20 > . It seems the maintainers don't want to use the "pmbus" compatible for= =20 > specific devices. The maintaners require an explicitly compatible from= =20 > device list in drivers/hwmon/pmbus/pmbus.c . >=20 There are two problems: 1. Describing your _hardware_ (not drivers) in the devicetree 2. Binding a driver to your device You ultimately care about both 1 and 2 as you want Linux to do something useful with the device, but for the purpose of this patch adding the devicetree, 1 is what matters and 2 is not really a part of the considerations. What needs to be the case is that the devicetree describes the device via an appropriate compatible string for the device (manufacturer and part number). Prior to that, the compatible string for the device needs to be documented in a devicetree binding. This may be the trivial- devices binding if there are no extra properties that need to be described, or you may need to write your own binding document for the device if it's more complex and one doesn't yet exist. So whatever is in pmbus.c needs to be fixed later on if your device is not yet supported by it, but that's a separate problem (2) to the problem you have here (1). Who is the manufacturer and what is the part number? Andrew