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 274A33033C3; Wed, 28 Jan 2026 15:48:26 +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=1769615306; cv=none; b=tSBp3bBhc11oKs3chBC62/CSOoG+CjFzVa8kVos+fuJy45XLcqyMtFyqLCqvyPdLHdnrp1YuWVLDMOSyn22tX9d8IT5FYBoyME7+aYop8sIKt92BEQ5gOAqIos1mhexlMJCvEGtLi9Kj0AbTUaP5oj1qNASns+OvLPZ1wU+swDM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769615306; c=relaxed/simple; bh=nMmyDWkQnV3I7GZMPlWVQ0MXtLcXBmX4DSwzNeO1os4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=S4eJahJhGMowej7V/zmuEoY4xt7a32VCPMKV2JVF8xsOMXfzbZb3uChbh50yO7yERlSJgJiTHrE55UO4/+N6D/ZQ+0A/QkRQLb7BJap9/4Ays4tBLzX8PxvLgwFFfgfF9fzFG2Iw+WlDr26G5+Hob1S3O0gD2YIOPrqUb+K8IYY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tQsU+VSH; 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="tQsU+VSH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31568C4CEF7; Wed, 28 Jan 2026 15:48:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769615304; bh=nMmyDWkQnV3I7GZMPlWVQ0MXtLcXBmX4DSwzNeO1os4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=tQsU+VSHZpjZdAXLTmABg/gNAXMA+TDHBfkk8V3n0zVkM7a0o/6nl5BSQiRifK2aN 1OvAANda2HLtuH7qYpR85cqB40xQBgKaNz9M7h8H+PHEWXUaLfsMEKVtwqD+P7rpIN MM+Cx3P/H9jr4YW9VqozqSaK1NS7QAN8jBelpjlM8nbziS2MVUTyU7eUn9R5FY/G6x UPTIAqx6Pm6ngLCDvIe8ioTGsvn845+T7IKfcTmlFaEkBlG/xusF/6YoX2Hc+Ix1lY HMhC5QZ2BQTakGSq6fzJO8WyCOL+VmxXNhvMio3a+NU7RSUj9dvMgxEclwGMSlymgR TnPDqqinB9+IA== Message-ID: <3db84b61-e463-4362-b142-59d3ca6eae90@kernel.org> Date: Wed, 28 Jan 2026 16:48:18 +0100 Precedence: bulk X-Mailing-List: linux-input@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v13 1/3] dt-bindings: i2c: Add CP2112 HID USB to SMBus Bridge To: Andy Shevchenko Cc: Danny Kaehn , Rob Herring , Krzysztof Kozlowski , Benjamin Tissoires , Andi Shyti , Conor Dooley , Jiri Kosina , devicetree@vger.kernel.org, linux-input@vger.kernel.org, Dmitry Torokhov , Bartosz Golaszewski , Ethan Twardy , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Leo Huang , Arun D Patil , Willie Thai , Ting-Kai Chen References: <20260127-cp2112-dt-v13-0-6448ddd4bf22@plexus.com> <20260127-cp2112-dt-v13-1-6448ddd4bf22@plexus.com> <20260127160217.GA3776731@LNDCL34533.neenah.na.plexus.com> <20260128-magnificent-faithful-otter-c4f900@quoll> 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: 8bit On 28/01/2026 13:49, Andy Shevchenko wrote: > On Wed, Jan 28, 2026 at 11:35:25AM +0100, Krzysztof Kozlowski wrote: >> On Tue, Jan 27, 2026 at 10:02:17AM -0600, Danny Kaehn wrote: >>> On Tue, Jan 27, 2026 at 08:47:48AM -0600, Danny Kaehn wrote: >>>> This is a USB HID device which includes an I2C controller and 8 GPIO pins. >>>> >>>> The binding allows describing the chip's gpio and i2c controller in DT, >>>> with the i2c controller being bound to a subnode named "i2c". This is >>>> intended to be used in configurations where the CP2112 is permanently >>>> connected in hardware. >>>> >>>> Signed-off-by: Danny Kaehn >>>> --- >>> >>> Hi Folks (Intended for Rob or Krzysztof), >>> >>> Wasn't sure the best way to go about this, but trying to see the best >>> way to get a message in front of you regarding an ask from Andy S. >>> >>> In [1], Rob H initially directed that the gpio chip share a node with >>> the CP2112 itself, rather than having a subnode named 'gpio'. >>> >>> Initially, I did the same thing for both DT and ACPI, but Andy S. >>> directed that ACPI should not have the node be shared in that way. >>> >>> With the last revision of this patch, Andy S. asked that I try to get a >>> rationalle from Rob (or other DT expert presumably) on why the gpio node >>> should be combined with the parent, rather than being a named subnode >>> [2]. >> >> Because it is explicitly asked in writing bindings. Please read it. >> >> Because we do not want Linux driver model affecting design of bindings >> and DTS, by subnodes present only to instantiate Linux drivers. I do not >> care about driver model in this review and I do not see any reason it >> should make DTS less obvious or readable. >> >> That's actually rule communicated many times, also documented in writing >> bindings and in recent talks. > > Does DT represents HW in this case? Shouldn't I²C controller be the same node? > Why not? This is inconsistent for the device that is multi-functional. And from > my understanding the firmware description (DT, ACPI, you-name-it) must follow > the HW. I don't see how it's done in this case. What is inconsistent exactly? What sort of rule tells that every little function needs a device node? It's first time I hear about any of such rule and for all this time we already NAKed it so many times (node per GPIO, node per clock, node per every little pin). > Best regards, Krzysztof