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 87F7561FCE; Mon, 15 Sep 2025 03:41:38 +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=1757907700; cv=none; b=Hs7SHKwEaTL15w+5ACAz435UsFd1Kt5XKx+saq6vnTD+kfX4gzvkpdF9MEi6CIFoK+gZEF74xJmF2aHJqQFIBbsoyQbRDDlkR9Avmlrmu7/nWZGkRebZZRTPd4VEy5dj2WQCRpsEV8TDJCXm0CwX+lLTiq+RwTwagYeWVFs50bo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757907700; c=relaxed/simple; bh=McZskAG0UGaWRlZ5lR1vVezxW/M358PczFizXXezyt8=; h=Message-ID:Subject:From:To:Date:In-Reply-To:References: Content-Type:MIME-Version; b=QsGWnVVKK/PJfk7yitSbI1CqctHegYCecMnB0iUgfU+oarg/0bbv/v8WHjMBwGERmdsWV5CktLJf34TGxOw3rb5KcF5UL4NQ+121YxEF0jHBLQmXlCusoGGIa9L7ry7dGCiQot/e3AKh6SoGT+SAtKc5UhgF3q94kRHlxHIilWM= 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=Xcvd+m79; 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="Xcvd+m79" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codeconstruct.com.au; s=2022a; t=1757907696; bh=McZskAG0UGaWRlZ5lR1vVezxW/M358PczFizXXezyt8=; h=Subject:From:To:Date:In-Reply-To:References; b=Xcvd+m79AusxjVSN/vAg8wz4KIWiLRryRepPb4eS0IUkszuJGo2V11TGyAvc1SqMi 9S1J8r+3SD7UrRoOwxjMpTx795/XvVFw55TE6h/q653GYizk/UiZY3p8+ZG5py3MP7 OxVCYfPKpPlqAQYZlTX7B83F2QFXuBVrf9xcIb7lNam3d38IAqjnvw3ipfAs2M9Pwv fASRz3/FjxRZNLV8ViFFG0k2VlfDS/im8a80Ib4zgQ1xSfa5RD7PNnf7ljaZYcwYk4 2HkpFpETo3rZWtUexQHqjsIV1JDMO9qPgU2t+FHY6y09m986X0HhKK9Cz15owqyw7N YG3MGYCBDbp2w== Received: from [192.168.72.160] (210-10-213-150.per.static-ipl.aapt.com.au [210.10.213.150]) by mail.codeconstruct.com.au (Postfix) with ESMTPSA id 68AFC64CF0; Mon, 15 Sep 2025 11:41:32 +0800 (AWST) Message-ID: <03abda47219b8b0b476a3740c7ed2acc4b2b16dc.camel@codeconstruct.com.au> Subject: Re: [PATCH v18 1/3] dt-bindings: i2c: aspeed,i2c.yaml: add transfer-mode and global-regs properties and update example From: Jeremy Kerr To: Ryan Chen , "benh@kernel.crashing.org" , "joel@jms.id.au" , "andi.shyti@kernel.org" , "robh@kernel.org" , "krzk+dt@kernel.org" , "conor+dt@kernel.org" , "andrew@codeconstruct.com.au" , "p.zabel@pengutronix.de" , "andriy.shevchenko@linux.intel.com" , "naresh.solanki@9elements.com" , "linux-i2c@vger.kernel.org" , "openbmc@lists.ozlabs.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-aspeed@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" Date: Mon, 15 Sep 2025 11:41:31 +0800 In-Reply-To: References: <20250820051832.3605405-1-ryan_chen@aspeedtech.com> <20250820051832.3605405-2-ryan_chen@aspeedtech.com> <9d6660f0bf5119cedee824cf764f15838622833a.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: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Hi Ryan, > > OK, but the ast2400 and ast2500 I2C peripherals - which this binding al= so > > describes - do not have that facility. Given the 2600 is a distinct per= ipheral (as > > discussed on the v16 series), this would seem to warrant a distinct bin= ding. > >=20 > > Should this be split out into an ast2600-specific binding, to reflect t= hat it is > > different hardware? The reference to the global registers and transfer = modes > > would then be added only to the ast2600-i2c-bus binding. >=20 > I agree it would be cleaner to split out a new binding file specifically = for AST2600, > for example: `aspeed,ast2600-i2c.yaml` > But also I think `aspeed,i2cv2.yaml` more better name, that compatible wi= ll=20 > support next generation such like AST2700 ..... The ship may have already sailed on that one, as you already have the existing compatible string describing existing hardware. I would assume that the compatible string should be fixed for an instance of the specific hardware, but the DT maintainers may be able to provide some input/precedence on changing an existing binding, if necessary. If this does get changed, I would expect that you would need a corresponding update in the old driver too. Or, another option may be to keep the current generation ("v2 core with compat registers") as-is (ie., at ast2600-i2c-bus), and introduce a new string for the next - where the primary hardware change might be the removal of compat registers, but it's still new hardware Cheers, Jeremy