From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 1AF7B494801; Tue, 13 Oct 2026 06:11:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791871878; cv=none; b=FLYG3xbeKRpFUVZxfmtAv5nIl+9In0JzdmtZM33d3LybqsJ1/245WhDsKMexTl3WSj12GQ0t/PVgE6pZ0U/pFsYihjicZdDQDwvF6zOR2BguFC389OaGE1pG1CdKgs691xa9lC8krog4x3Tdhe7mcrJ/uqhJjeipcUu5YPQs7Ac= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791871878; c=relaxed/simple; bh=6P/KMeGkNJRqtPOx3PtlRJJ0A6uRzmT744jflR6cPIU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=iIhJUISgnoyoapp6E5t5Jnh4M6fd0qOYP8Od3pzN0Krj9TP/VMAFdcZCbYu9Y+NveFBj3pMPs7RJIA68slsz8uXsShncBgwX2rw3m8epdVI8qFBCU9E8C+LUrOWIOoC/8aR0aVOHAI4TfOR/ilgYOl/VDCH6um5vqt2VBoCPmO4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GAvkk0Lf; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GAvkk0Lf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E6341F000FF; Tue, 13 Oct 2026 06:11:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791871875; bh=YgKgrdCbYrKNqKmmilqEA/C7pkoF4WC+apj6WJz3DtI=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=GAvkk0LfD+4vBLjJ9DyaVv/bBbS9L6KW4OQ9qrhzXQXbEUWZvChCzurFrJg3F99x6 7zhaQvZRNLGURdhd9UyJAMGicZ+78WALgeA5f6IpvGOJqCo2VGRBibvmIUoSbuJJAD p4UPaAl6t86Y1CJUOZcsiMC7TaFDmRU0z8H6qi6nyRcNct3qqlE54EJ5Mn/Oz2r/Me djkER95TAbZpa7lv+5CXysAk2Ir4kSKYlipi+h2nqtbW5MeJqNfwk3mGuvySjEOcgE n4VjmeUXfqtH/TfJk0tVBkGX7P9qeWFeoCTyvQJ9+8opDIHi38/zfinbgRwT7p90ue uP9c9+THGjNdA== Message-ID: <58cbdffa-7574-4daa-851b-dbb50012f158@kernel.org> Date: Tue, 13 Oct 2026 08:11:09 +0200 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 02/11] dt-bindings: i2c: Add NVIDIA LSTP I2C To: Adrian Ambrozewicz , Andi Shyti , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: Donald Shannon , linux-usb@vger.kernel.org, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman References: <20261012-lstp-usb-adapter-v1-0-aambrozewicz@nvidia.com> <20261012-lstp-usb-adapter-v1-2-aambrozewicz@nvidia.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/10/2026 19:36, Adrian Ambrozewicz wrote: > Add the binding for an I2C controller channel of an NVIDIA LSTP USB > adapter. Peripherals on the bus are child nodes, as for any I2C > controller. The device sets the bus speed and the protocol cannot > change it, so clock-frequency is not supported. > > nvidia,retries sets how many times the host re-issues a transfer that > failed on arbitration loss or a busy bus (default 3). The generic I2C > controller schema has no property for this. A device that reports its > own arbitration retries handles both cases itself, and the property is > ignored for it. > > Signed-off-by: Adrian Ambrozewicz > --- > .../bindings/i2c/nvidia,lstp-i2c.yaml | 71 +++++++++++++++++++ > MAINTAINERS | 1 + > 2 files changed, 72 insertions(+) > create mode 100644 Documentation/devicetree/bindings/i2c/nvidia,lstp-i2c.yaml > > diff --git a/Documentation/devicetree/bindings/i2c/nvidia,lstp-i2c.yaml b/Documentation/devicetree/bindings/i2c/nvidia,lstp-i2c.yaml > new file mode 100644 > index 000000000000..eacabed52cd1 > --- /dev/null > +++ b/Documentation/devicetree/bindings/i2c/nvidia,lstp-i2c.yaml > @@ -0,0 +1,71 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +# SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved. We do not use that tag. Drop it everywhere. > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/i2c/nvidia,lstp-i2c.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: NVIDIA LSTP I2C Channel > + > +maintainers: > + - Adrian Ambrozewicz > + - Donald Shannon > + > +description: | > + I2C controller channel on an NVIDIA LSTP USB device. Say something useful. > + > + Peripherals on the bus are described as child nodes. An i2c alias > + gives the bus a fixed number. What are you describing here? > + > + The bus speed is set by the device. The LSTP protocol has no way to > + change it, so clock-frequency is not supported and is ignored. > + > +allOf: > + - $ref: /schemas/i2c/i2c-controller.yaml# > + > +properties: > + compatible: > + const: nvidia,lstp-i2c > + > + reg: > + description: Channel ID reported by the device firmware. > + maxItems: 1 > + > + nvidia,retries: You described the desired Linux feature or behavior, not the actual hardware. The bindings are about the latter, so instead you need to rephrase the property and its description to match actual hardware capabilities/features/configuration etc. > + description: | > + Number of times the host re-issues a transfer that fails on > + arbitration loss or a busy bus before giving up. > + > + Ignored when the channel config reports non-zero bus arbitration > + retries. Such a device is expected to retry both arbitration loss and > + a busy bus itself before reporting failure, so the host adds no > + attempts on top. > + $ref: /schemas/types.yaml#/definitions/uint32 > + maximum: 255 > + default: 3 > + > +required: > + - compatible > + - reg Incomplete, where are any resources? If you do not have any, then this should be folded into the parent node. > + > +unevaluatedProperties: false > + > +examples: > + - | > + interface { > + #address-cells = <1>; > + #size-cells = <0>; Why do you need that wrapping node and what is "interface"? > + Best regards, Krzysztof