From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f172.google.com (mail-oi1-f172.google.com [209.85.167.172]) (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 3C1F3356A12 for ; Mon, 2 Feb 2026 22:48:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770072520; cv=none; b=pi0fJ6gQPJMWd18zMHaLsb7LXxFLzlXx4FH4yuj+LM9GUUbQh4bsLIGJChalgjz+g/iOm+9hdw0l3dQKaCc4tESVsLTpxBsiDiGjtX4ZAa5hB18JnloL1O+uilf0ArKjFsxVVuoWglsSj4ORM4rcLxO6Qn4rRw1lqLzL9j4GM+E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770072520; c=relaxed/simple; bh=o3Bn8QuqwePy51tzC7oXfrEiDa31Kqfqd3Ab1p5UScU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=h/W8PqWY2SieSS+CKiTGITchJmP+JIXYwvSykQijuWDG9LnmpJn2p1dDTmBDnLW1eyj6X7Q3BT3Qz/1nGRt8fOvxgo7fJ3FLMHKwZA4vl4lxlFbNjR6SLERXhiiIPAbuz5q3toziSdo6e3ZNZ2JsFWxEaJIqFbP9QCFrBadEbQA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com; spf=pass smtp.mailfrom=baylibre.com; dkim=pass (2048-bit key) header.d=baylibre-com.20230601.gappssmtp.com header.i=@baylibre-com.20230601.gappssmtp.com header.b=qEindJno; arc=none smtp.client-ip=209.85.167.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=baylibre.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20230601.gappssmtp.com header.i=@baylibre-com.20230601.gappssmtp.com header.b="qEindJno" Received: by mail-oi1-f172.google.com with SMTP id 5614622812f47-45c962424daso2043891b6e.2 for ; Mon, 02 Feb 2026 14:48:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20230601.gappssmtp.com; s=20230601; t=1770072517; x=1770677317; 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=JSAtrL+Y9tqEZj9ofXU44Yu8l9qg/1Ym7mvkc+EsokY=; b=qEindJnoB18ZPd1pxdTXOjRog7jNXPfBKyYS8XoNguHmuM/X01H5ZsdhhOQ5do0/96 WGtR8omuW3XkEutgE4JHcZ4IktXcht0YfTsQbTrg0pSsvTilP8ay/Mw/aDvhHOENug9E 4q1XoAcnay7QoRfbtRfWPD1Rz+ZspNm85jZ1nAS0fIzr6QpSE2qHR+NCRq4PakSIIxg/ nFmaWNPdYA/G3sTnfK8o1UbQt4t1HsdmMWdWnA9bePWH4gDPANlySzBLY58l/bbTDg7V /KO75u2bLzKAHg77233mFhwXaC0WANl7inhYAGwCYmsyMxii1XjLFYQZQzybUOL1AUHg sdjw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770072517; x=1770677317; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=JSAtrL+Y9tqEZj9ofXU44Yu8l9qg/1Ym7mvkc+EsokY=; b=DievfoAtTb8OA0D5zM95T+8GbWH2xXamnIswsoaSvusCc/lK1MfQRyAi4F4C5rs7pb vvlkqg/9htO80mn16kU5btDJepxw6QPbPSIn/em0Z0vAQx+Vi7wuxP7WJNig4Ud5aN8D hKzVcLCSISZS807gGp6nIgOU4Ow1VHmzZmW6LguZ/m26KHRGfw7hNYFTw+bZaK/ecLRw qmgkeyqLl1Pvpt6ixIcxEIq3etLPiTHAy4donQ/0dEwpVSIVprOzzB05NFP6rGEh8BHQ G+5x99wjPxob1/wp/eXTLPuhVJtRy5+IN6ZsxdoA4ofUDcFdd0zPMKyjaAhERU4H3rj3 8vVQ== X-Forwarded-Encrypted: i=1; AJvYcCW7S6d3k2EqJ8MX7Huad3M79ySK3c1QrWq8oh+Afo0jprZq/lkQ7AEConQtku91+zG4iUq80xCNtg5rFSA=@vger.kernel.org X-Gm-Message-State: AOJu0Yzb5GYbv/JbFJpBegnxrrMfREEUBVg+JQWhpn+MIXHNNjtNECpe 4xJbdDZev2MMMsGbHp/F8T6m3xEx7KGKXn0Qt2SVSkmeyhLgjBVvmxoZhEHgpBolURA= X-Gm-Gg: AZuq6aKVtVvSdrQTdTGSCyj628JS5znFL77s1MzyEGJ7QD+kdr3xmbxiNW2NzdL1uFd Eb2OPiHmxJWwO+vKOo1zJUdm5WW9O9lJnyQKcG+ZOZ845nm2apAfJ9aR/96xNS0og4qri5RjuCE 7uvY8jEuGZmChoVr2NSn1eW3tBYPVZqN9TkkjDHlKnnf/D323/cpxaeJ2kg4QNFbo5xtyQNc0AN wK4pO3tD9Ej4r6LdJ7Ja6pbzDJu9oI62O04tz26SRLSAHbngROXUZ8VNqOXq8SU2J6FZpErRJKd vPWRxfxt0tGkeIJ7uut5T11kyQvlh+B8h8p88Lodrnjv71/0wYLQGrKIx4Cm8nBh1AYdhg71iIa DKMI7mssEep4F2oD/FOh09Ck+tTbkPlf346XEY06v49I22lOeuXGi21zLczQJqmfMtwptRZxqOa hndOr8urtHHVi2ATyHCRqA82qY+cAIV5YZbCXrtGVSL0Es9lSDdwtBzUnhWJ3r X-Received: by 2002:a05:6808:5391:b0:450:caf8:eba2 with SMTP id 5614622812f47-45f34d405e0mr5752387b6e.57.1770072517226; Mon, 02 Feb 2026 14:48:37 -0800 (PST) Received: from ?IPV6:2600:8803:e7e4:500:3695:6954:27c2:42ef? ([2600:8803:e7e4:500:3695:6954:27c2:42ef]) by smtp.gmail.com with ESMTPSA id 5614622812f47-45f08f22826sm9856970b6e.11.2026.02.02.14.48.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 02 Feb 2026 14:48:36 -0800 (PST) Message-ID: <086d6b35-8c19-4e92-9cd1-557b98991d35@baylibre.com> Date: Mon, 2 Feb 2026 16:48:34 -0600 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 2/2] iio: light: Add support for Capella cm36686 and cm36672p sensors To: Erikas Bitovtas , Jonathan Cameron , =?UTF-8?Q?Nuno_S=C3=A1?= , Andy Shevchenko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Kevin Tsai Cc: linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org References: <20260201-cm36686-v1-0-4949a2a9ba63@gmail.com> <20260201-cm36686-v1-2-4949a2a9ba63@gmail.com> Content-Language: en-US From: David Lechner In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/2/26 6:04 AM, Erikas Bitovtas wrote: > > > On 2/1/26 8:45 PM, David Lechner wrote: >> On 2/1/26 11:03 AM, Erikas Bitovtas wrote: Pro tip: when you reply, trim out the not relevant parts like this. It was hard to find your actual reply. ... >>> +static const struct iio_chan_spec cm36686_channels[] = { >>> + { >>> + .type = IIO_LIGHT, >>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | >> >> IIO_LIGHT should have IIO_CHAN_INFO_SCALE to convert raw to convert the >> raw value to lux. If we don't have that info due to lack of documentation, >> then we should add a comment to explain that. Or maybe we can make an >> educated guess? > No documentation on this is available, but we know that ASUS in their driver for > cm36686 use 160ms integration time for light and, after applying their custom > calibration functions, divide received raw value by 25 if the device is cm36686, > or by 20 if it's cm36283. Maybe from there we can extrapolate the lux value like > this: > 80ms -> raw / 12.5 > 160ms -> raw / 25 > 320ms -> raw / 50 > 640ms -> raw / 100 > Not sure how accurate that would be, however. > Xiaomi gets IIO_CHAN_INFO_SCALE by multiplying a value retrieved from a device > tree property called "als_trans_ratio", which is not documented anywhere. The ASUS driver is an input driver, not IIO, so not sure that helps. We could start with hard-coding the als_trans_ratio in this driver for the scale (and write comments explaining where it came from and what we know and don't know). Then at least we would have a scale. And if anyone needs something more accurate and reverse-engineers it we could fix it up later with a DT property or something like that.