From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f52.google.com (mail-wm1-f52.google.com [209.85.128.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A34A11A8405 for ; Wed, 26 Mar 2025 10:26:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.52 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742984772; cv=none; b=Mt9qL7ev24VEaO/B9PQavi2qiL34VJ4yrEB0JD3wkaxaiYR1onL4kNNArXSDvLysCNofZHFno7E0JjHcVPxYZHKSVSIggRmq6+8s0JUxRy0+9EluNFfvErOnfU8AmSOBswmL8Mb5mTl4s/ib4ZtqOzIDVaWkvYCTf3jgAwt8f+A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742984772; c=relaxed/simple; bh=VmZW3dYOkE+WcIdW+rTFDYurYECcNeudvlHZ1LESI8I=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=FwTKJ35wTsCKi3fBgAsq+IWmjdjcoSgc2duZWUdod10vNraDB41mhEkgbT+3JtCvBzQN3YWF0myukBSfM1+myx4NPDVxd6nM59pkhLp1FfF6mIRB384v+8PcpEYuqC+QImPykXhHxrGrHuihKAg5I8Ib6XgLoXwq00PcTnqQdWI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=XPPhUaHM; arc=none smtp.client-ip=209.85.128.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="XPPhUaHM" Received: by mail-wm1-f52.google.com with SMTP id 5b1f17b1804b1-43cfe63c592so63824295e9.2 for ; Wed, 26 Mar 2025 03:26:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1742984769; x=1743589569; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=98hcAito2MMtQTY1iL6KWHxMYRyo687ywiMmqIh+p7A=; b=XPPhUaHMMHildxl7E/pGbg3LqEdcenwWvdjeuLPj1f8OT7a6BYtjs2bu24XtbAnFFY s9+jVhzzy9BFkI3JMO+QBwfdpCUz6XYuPUqDbZPhh1GKp+3K27W5+fCppeyI/7od9GV5 scsDjSsDhiRkFPWlWeter1dzRKgY0BJ24tX0Zakn7d3gRB/jl78ONFJba5+ry4db+fqB w+6iIB3FLjU3RMJ99bkzWnP317J2KjottjvJYV3+hj66I0kjq40id1xBzpo5I2EkX5wd w/9qMcNz3WXfeWm2gcUcFe6Pwo2OXAUJ2wzYK+dfZXPPfP1ln1vMQLy1bUed15eH795l DSVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742984769; x=1743589569; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=98hcAito2MMtQTY1iL6KWHxMYRyo687ywiMmqIh+p7A=; b=JqfMAMrP3KDlTn9ae30bJRufJ8wtu5AU86gp54UnwRAk8LYG7zABRi9R0RJw5tpGY/ dp+l2yvr20BZOU/KjKt46gKEcYR1k8m5ngmXWP5XChHEYS4kukdkhkWHpc/2Vxa8DfhS BFMA6e1Kvr6qyzp0meo++ZFH0jsag4/hnf0wzNYmV3OYQIEWW+sP/eBHJNWI1bMIGjJa cjfFYTcse1aIYL1+GyCyT25AUR4jeR3BZHLqXgmETC0U6I2iQigj82CB3O1j5WBypvTS VVeIBlDYKH2CgFlKrIX6QgpcokT0BFFJsNw+cMLyMbcYcui4XA/JF9Eay/+Dm4KqPMMi I5Cw== X-Forwarded-Encrypted: i=1; AJvYcCUp9df03tpplqlSnzqTWszojsbTg0uoLsY6Z+bEMd4xmiZX87klB88z2hjma28M3ryF2bh5obXNrhnES0g=@vger.kernel.org X-Gm-Message-State: AOJu0YyPUZg7iaq5pvHH53SMk9rpgi+6o4yJek6Bh2mIv0auwSDgL8qz 11RSuK6+M06Cy0gI3hGCST0+X+bP/rQM5FsoPlCWWapvoQF377XMfRk+Tt3OQxMvck03GilZPrq IxjM= X-Gm-Gg: ASbGncv7BP9GpqojDPzrOQjWnkckhdEZonBPJ+R9YeMH3bza/Un16gbv8bMvDyOc2ja RYcjFksTfudepteqKP9C78H+uI7xRPwlaU/+ZwRH2ZZXQBAnv8dL6JYLh8jtM1fP+oX7T95+Nma /IPLnZeVhjjga7YBmoHCBWtrY0mQq0wH98ma7Q0nU26mta+Kxl35mbXxSAUPXb4dbtyX6eofVEL g6t1suj1PKSOCqTJ0//t7hU6Uyg86rRUNNvnxwKX5lAb6wgk09KRvg1VXihdOarwKhCGJhAX3Bx 0A82d7uwsc4HBzRatneusUxZxLVxqxyDc0kjM/oY8KJ0q5RgBYzWN8QhlSHV+e2y+Pb8TBuw3go = X-Google-Smtp-Source: AGHT+IFNIgbM5SxndZJ31+RxAuvmVblk7zrUQEK1IUI9dhFX9c6aTpE7fdxiqMV2lHxT/eOf35nkUw== X-Received: by 2002:a05:600c:c0d:b0:43d:738:4a9 with SMTP id 5b1f17b1804b1-43d50a33d03mr154416225e9.27.1742984768921; Wed, 26 Mar 2025 03:26:08 -0700 (PDT) Received: from [192.168.1.38] (i5E863BED.versanet.de. [94.134.59.237]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3997f9e6651sm16436745f8f.75.2025.03.26.03.26.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 26 Mar 2025 03:26:08 -0700 (PDT) Message-ID: <5060c248-3160-4d52-81ec-8e06bbd246bf@linaro.org> Date: Wed, 26 Mar 2025 11:26:06 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 1/7] dt-bindings: input: syna,rmi4: document syna,pdt-fallback-desc To: Krzysztof Kozlowski , David Heidelberg Cc: Dmitry Torokhov , Rob Herring , Krzysztof Kozlowski , Conor Dooley , "Jason A. Donenfeld" , Matthias Schiffer , Vincent Huang , linux-input@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, phone-devel@vger.kernel.org, ~postmarketos/upstreaming@lists.sr.ht References: <20250308-synaptics-rmi4-v3-0-215d3e7289a2@ixit.cz> <20250308-synaptics-rmi4-v3-1-215d3e7289a2@ixit.cz> <20250310-hissing-vagabond-pegasus-cc8aed@krzk-bin> <3c5e12fc-eb91-46e8-a558-9896f0bdcab4@ixit.cz> <48bb62eb-8aa9-465c-9e77-c0b375df0c9f@linaro.org> <492da0ab-3a5c-4ee9-bc37-d66b007ffd81@kernel.org> Content-Language: en-US From: Caleb Connolly In-Reply-To: <492da0ab-3a5c-4ee9-bc37-d66b007ffd81@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 3/26/25 07:57, Krzysztof Kozlowski wrote: > On 25/03/2025 14:23, Caleb Connolly wrote: >> >> >> On 3/25/25 08:36, Krzysztof Kozlowski wrote: >>> On 24/03/2025 19:00, David Heidelberg wrote: >>>> On 10/03/2025 10:45, Krzysztof Kozlowski wrote: >>>>> On Sat, Mar 08, 2025 at 03:08:37PM +0100, David Heidelberg wrote: >>>>>> From: Caleb Connolly >>>>>> >>>>>> This new property allows devices to specify some register values which >>>>>> are missing on units with third party replacement displays. These >>>>>> displays use unofficial touch ICs which only implement a subset of the >>>>>> RMI4 specification. >>>>> >>>>> These are different ICs, so they have their own compatibles. Why this >>>>> cannot be deduced from the compatible? >>>> >>>> Yes, but these identify as the originals. >>> >>> >>> It does not matter how they identify. You have the compatible for them. >>> If you cannot add compatible for them, how can you add dedicated >>> property for them? >> >> Hi Krzysztof, >> >> There are an unknown number of knock-off RMI4 chips which are sold in >> cheap replacement display panels from multiple vendors. We suspect >> there's more than one implementation. >> >> A new compatible string wouldn't help us, since we use the same DTB on >> fully original hardware as on hardware with replacement parts. >> >> The proposed new property describes configuration registers which are >> present on original RMI4 chips but missing on the third party ones, the >> contents of the registers is static. > > > So you want to add redundant information for existing compatible, while > claiming you cannot deduce it from that existing compatible... Well, > no.. you cannot be sure that only chosen boards will have touchscreens > replaced, thus you will have to add this property to every board using > this compatible making it equal to the compatible and we are back at my > original comment. This is deducible from the compatible. If not the new > one, then from old one. hmm I see, so instead we should add a compatible for the specific variant (S3320 or something) of RMI4 in this device and handle this in the driver? I think that makes sense. > > Best regards, > Krzysztof -- Caleb (they/them)