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 D8B6C2571C7; Sat, 9 May 2026 14:46:10 +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=1778337970; cv=none; b=CDACXt5CaUPZIQjRNXBmzdKAQX2paGJyLx2o0W1s2ytK/QcdcmdNoi1qpEnhE8MWUSCwVxPd1K/JLxnmaKuqInD5KQ7R851lF1oM46ZExeA8+lv9jpvXWBpXzbiCsWzyUMzQygaL+LVKwzNs63Qlu6WRWC7jVIuC1j/efc4dmus= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778337970; c=relaxed/simple; bh=i5fKdGSPuWGbNpYa1XMgwdSm8esm6Qe9Wqc5n6R9HdM=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=RdI54H/Rwg1IzGTbU0Sx9BPnrrYILIffZXKnKqUwP6LYa5frT6iNG9g1VedE5OnPJHhlWHYD/q7qCLtmXh6Am0qsOUyAzALs59DRjajnwbunblOGEKHnt8eO+vvIw0RBGcCUrsTFJZ3IEEtqA++ON0Bbj1FtjV3GHPtVy09otX4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jLLxh5K7; 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="jLLxh5K7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0336C2BCB2; Sat, 9 May 2026 14:46:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778337970; bh=i5fKdGSPuWGbNpYa1XMgwdSm8esm6Qe9Wqc5n6R9HdM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=jLLxh5K7MGuIvPBwvnLXuIGcSqlW09X4ULF4eNXAahm99fMeNdGt+PXs4+bcOUZNx U/jw/h1K0TIaMQSbtZgt4W0VFFsfvPAJ0MMFGcfqLCayf2m5OfvexXgOLBAY1UKmkJ VsZYa3/u086PJsGCKokRPa2KJwdJ+QmmNt6mMFPekp36B4d7aYCHtLzQiSpERcgy0E 9nhgnC7XM+tD3uPs25JPoAelaKecJCuRg4SPsLIEr0mJNa4cM6Ex12OJoWt58FY24U WnakglfT//LknVxSHh/O6OaxOghiZo9R65ssMT39EXU6eHbyl5u1yLKDahyf5+RnMp wPJnu5Sz73zBQ== Date: Sat, 9 May 2026 15:46:00 +0100 From: Jonathan Cameron To: Nuno =?UTF-8?B?U8Oh?= Cc: "Stan, Liviu" , Lars-Peter Clausen , "Hennerich, Michael" , "Sa, Nuno" , David Lechner , Andy Shevchenko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , "linux-iio@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 2/2] iio: temperature: ltc2983: Add support for ADT7604 Message-ID: <20260509154600.02e2d11a@jic23-huawei> In-Reply-To: References: <20260427132526.272716-1-liviu.stan@analog.com> <20260427132526.272716-3-liviu.stan@analog.com> <20260508121441.39ad9f65@jic23-huawei> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Fri, 8 May 2026 17:13:14 +0100 Nuno S=C3=A1 wrote: > On Fri, May 08, 2026 at 02:48:39PM +0000, Stan, Liviu wrote: > > On Fri, May 08, 2026 Nuno S=C3=A1 wrote: =20 > > > > On Fri, 8 May 2026 Jonathan Cameron wrote: =20 > > > > > > Will defer this to Jonathan but if we can have a real of the co= verage > > > > > > given the temperature, I guess this is ok. Given that I think w= e don't have > > > > > > a better channel (unless we add one?) for this. Or just extende= d_info... > > > > > > =20 > > > > > > > > > > I have no idea what coverage percentage means in this case. > > > > > Can you provide some more details or a reference? Google isn't g= iving me > > > > > anything useful. =20 > > > > > > > > A leak detector is a sensor like the raindrop detection modules, wh= ose > > > > resistance decreases as more of its surface is contacted by liquid.= In this case, > > > > for example, if half of the sensor's surface is in contact with a l= iquid, the > > > > ADT7604 should, with an appropiate user-provided resistance-vs-cove= rage > > > > table, report 50% coverage in the IIO channel. =20 > > >=20 > > > And, AFAIU, depending on the coverage the resistance changes and that= 's > > > how we get into the indirect temperature variations? =20 > >=20 > > If I understand your comment correctly, you're implying that there are = indirect > > temperature variations caused by resistance changes, and that's what th= e chip is > > measuring? The chip does not measure any actual temperature for this se= nsor > > type, the value in the temperature result register bank is solely a res= ult of the=20 > > chip's interpolation of the user-defined custom table. > > =20 >=20 > I meant that's what the table is trying to accomplish? That's why I kind > of put it as "indirect". My understanding was the chip does not measure > any temperature as well. Ok. So what are our options here? Present it as simple resistance and leave userspace to figure it out or add a new channel type? To me feels like new channel type makes sense. Jonathan >=20 > - Nuno S=C3=A1 >=20 > > Liviu =20