From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.lysator.liu.se (mail.lysator.liu.se [130.236.254.3]) (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 A7A34361DBA; Wed, 9 Sep 2026 05:25:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=130.236.254.3 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788931555; cv=none; b=EyYi6fMYSlIfH5uxTzbDD6zNUj9Z7quHg/MZ1oeowmVU7F/WdXyhogWwjcvCjt1Lk8awtC8iNDCWc05E6h1ZTj7YLJJx0N9CYO2fZ3Ne1e6teDNlZtAHBvpwlrXDfaEs4OUoIIrz5NYkHmeleMbyCTAzSsqTRSLT65IszhfSoR8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788931555; c=relaxed/simple; bh=TBSjd0wHBttYMB73JiVfFTcNAzvAyF40gt/CVFr51bQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=i4h47yNMHiKjDKnjZptAGtf+uGl+iOh7fa3xAmxAyfHf+60AQ7F/nzabQy2i5PEgOqpG/8fD3LFD+BEQooDi8GOz3tJuZb15nNgvrWtgkXwmVBC2nzOm1pQxIolssqLbuIA9JvYAgcrrdidgHSaSC1obKYurxSsW4MsgviRl/6c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lysator.liu.se; spf=pass smtp.mailfrom=lysator.liu.se; dkim=pass (2048-bit key) header.d=lysator.liu.se header.i=@lysator.liu.se header.b=IE33cti3; dkim=pass (2048-bit key) header.d=lysator.liu.se header.i=@lysator.liu.se header.b=IE33cti3; arc=none smtp.client-ip=130.236.254.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lysator.liu.se Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lysator.liu.se Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lysator.liu.se header.i=@lysator.liu.se header.b="IE33cti3"; dkim=pass (2048-bit key) header.d=lysator.liu.se header.i=@lysator.liu.se header.b="IE33cti3" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=lysator.liu.se; s=2026; t=1788931540; bh=TBSjd0wHBttYMB73JiVfFTcNAzvAyF40gt/CVFr51bQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IE33cti3TPZUSWoD9ir4u8uMBs5ntrvqHwpU94eORjuIRa6vN4MFFMqH8FGEytXlo 9swva8XvWcrjKNImhEyeS/6lQGCB3o4EG+SFt73Kin6KtWcJpdtVWTP4KLCoREFeqF vG/fCoti0X0FVx6GGUoMQa8VWYup5chiRZpRvMhy0Ddkh6L+llkIr4jOGvWDdoer8n 7FJkegfNVsS8oMGtItbFW+Hs1J1REWAv7oxC8zXCWhe7HSfmLeTe2eq+Q+G1wprqgi Tpg77084L6HBhTrxK4rghFsGF0UUGIL7lsDVfGjxVlmAuvsKvXaOFU25xcq/Cky2df n3n3yrdABlEuQ== Received: from mail.lysator.liu.se (localhost [127.0.0.1]) by mail.lysator.liu.se (Postfix) with ESMTP id 1E2F8134E5; Wed, 9 Sep 2026 07:25:40 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=lysator.liu.se; s=2026; t=1788931540; bh=TBSjd0wHBttYMB73JiVfFTcNAzvAyF40gt/CVFr51bQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IE33cti3TPZUSWoD9ir4u8uMBs5ntrvqHwpU94eORjuIRa6vN4MFFMqH8FGEytXlo 9swva8XvWcrjKNImhEyeS/6lQGCB3o4EG+SFt73Kin6KtWcJpdtVWTP4KLCoREFeqF vG/fCoti0X0FVx6GGUoMQa8VWYup5chiRZpRvMhy0Ddkh6L+llkIr4jOGvWDdoer8n 7FJkegfNVsS8oMGtItbFW+Hs1J1REWAv7oxC8zXCWhe7HSfmLeTe2eq+Q+G1wprqgi Tpg77084L6HBhTrxK4rghFsGF0UUGIL7lsDVfGjxVlmAuvsKvXaOFU25xcq/Cky2df n3n3yrdABlEuQ== Received: from gryt (81-225-28-11-no2391.tbcn.telia.com [81.225.28.11]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by mail.lysator.liu.se (Postfix) with ESMTPSA id ADD5B13531; Wed, 9 Sep 2026 07:25:39 +0200 (CEST) Date: Wed, 9 Sep 2026 07:25:38 +0200 From: Peter Rosin To: Conor Dooley Cc: Shiv Prakash Gupta , andi.shyti@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, vikash.bansal@nxp.com, priyanka.jain@nxp.com Subject: Re: [PATCH 1/2] dt-bindings: i2c: Add NXP PCA9641 I2C bus master arbiter Message-ID: References: <20260908123146.1839854-1-shivprakash.gupta@nxp.com> <20260908123146.1839854-2-shivprakash.gupta@nxp.com> <20260908-skirt-makeshift-2050f3bcbb22@spud> 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: <20260908-skirt-makeshift-2050f3bcbb22@spud> X-Virus-Scanned: ClamAV using ClamSMTP Den Tue, Sep 08, 2026 at 06:47:01PM +0100, skrev Conor Dooley: > On Tue, Sep 08, 2026 at 06:01:45PM +0530, Shiv Prakash Gupta wrote: > > Add device tree binding schema for the NXP PCA9641 2-to-1 I2C bus > > master arbiter. > > > > The PCA9641 arbitrates between two upstream I2C masters competing for a > > single downstream slave bus using a lock/grant ownership model. The > > binding supports an optional 'interrupts' property for interrupt-assisted > > arbitration. > > > > Signed-off-by: Shiv Prakash Gupta > > --- ... > > + i2c-arb: > > + type: object > > + $ref: /schemas/i2c/i2c-controller.yaml > > + unevaluatedProperties: false > > + description: > > + I2C bus node representing the downstream slave bus controlled by the > > + PCA9641. Downstream slave devices are declared as child nodes here. > > Why does this node need to exist? Can't the i2c-arbiter node itself > contain the child devices? For symmetry with the pre-existing I2C arbs, which all have the extra node for historical implementation reasons? I don't know if that's considered a valid reason? I prefer to have all arbs follow the same structure... The "documentation" describing common I2C arbitration details went missing here: https://lore.kernel.org/all/20230731163833.319258-1-krzysztof.kozlowski@linaro.org/ Cheers, Peter