From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f48.google.com (mail-oo1-f48.google.com [209.85.161.48]) (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 585CC4BC017 for ; Wed, 29 Jul 2026 14:22:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.48 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785334936; cv=none; b=mXCYVerBR5y8o4TX9NmOhdSbw8AU/P1W4PlNx5lV+pAhHRuZp7oS4Za/XzS0qxDqydLSBTNqbR8GBZh91ThPzgTo1F04x5ax3EKSN6PGDtvD3dHKGqZMu73YMRN56cficBpwcWnSr6dDUa2F19m5T5XBQrLvgtscf3q2xWWpkUI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785334936; c=relaxed/simple; bh=wfthrTkDQg+zXZkKyFIKQ1Q32bcyZi6WCgNCplThDEo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=cDGeS/FaWY5bdNU/UTUtgviZY7cdGABX+8Zjgk8Xata8tv2TgGZMvw9gddm0vza0wQ7oh2KM3Wt71GEzD2To9DQWjgifsafDNfrkn36UaVYsSMxmtEtcmpZAiYPt5T6daKIun6IxXbGFeyRaL7qZ83GmkRtk+DQ3w9FIfWgS2eg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=roeck-us.net; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Zu7vlek6; arc=none smtp.client-ip=209.85.161.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=roeck-us.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Zu7vlek6" Received: by mail-oo1-f48.google.com with SMTP id 006d021491bc7-6aae4823f62so411591eaf.3 for ; Wed, 29 Jul 2026 07:22:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1785334933; x=1785939733; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:sender:from:to:cc:subject:date:message-id:reply-to :content-type; bh=aBs0uk/Nz7BeNh47t+Q3dnJOuZWHDf1CUHbRfB2n60M=; b=Zu7vlek6cx4S3C9lKbOA13aJ+03kEKHYnKklrVbhOtplebZcoCcgWd1jYoS4Oi2npo 5EoL0Oyv0TE3A/z/ioNAAqsdlFZFDfzW+FssehwYHyxiVHesVQQK7IojsIVfp2fcg7OZ UvoteJDnPf9Pq2F2VCfXU8X2l+AR5rda+Ctm7HAG5hjVVW/xYvFOPYB2IsVScdDGEVgY WQHK+s6iSZmVbLPrOjmU65uh76nu5kBZz67ajBo067+DapsQJG3EygP+waMhsLyGCteW V3doNiC+kNmLjwkDXe71Fvhl3Zn1kflKcFtFBJZNb9iIj69LJ/2Vebv5U9tm76y1DnyD G6zw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785334933; x=1785939733; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:sender:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to:content-type; bh=aBs0uk/Nz7BeNh47t+Q3dnJOuZWHDf1CUHbRfB2n60M=; b=iybMaz5+CeCEbbxClYtgXohv4Zx9+TpKzyZBOXyRQ8D9oUO1QRmk/bCfj9axyHp/Pw 2JHG6YkaMYwboskb9UDwZcoojT13voBu0cKA9yL+5XY/LyV3BtTXfEE2c0Cc+2+Aa8iS RcFszbtws+dRKEgOOceftb0AQmWMoXq75u3BarbrU7PnlTchto4k1XvhYzdDoTiBHpZ1 K4z4v67FcCErwEAYGMyDDNPRqh0wh4c/4erwT6qIiCWnk7iVe2ozsCZkj75gXczbBlKF Udv5qFTlVOXahMw8Cbq6UJog8eK/V+w4fC4RuAQh6xh5t58HsQoDNQr/HIsWtLkg7B9T WJ/Q== X-Forwarded-Encrypted: i=1; AHgh+Rpzi0gx0R8m9goYtKMuE74s65muQBmCcLBnc6glP5pXG4u9xwzB8/wSKaSr/2/4RfElNcTMsVo1RU5u+vs=@vger.kernel.org X-Gm-Message-State: AOJu0YyFlEHLVGgvdnP1WQKmwE7U8evlQ37Dsaq1vhhO2rvderlXk1YJ rkF0pjlCtFc9OVChX8DubFUN3aFiV6dlwhz61Go+8MFUdYSMuKbwR/6V X-Gm-Gg: AR+sD12s3XGWMP1ZL/cxYu4MDGdolSDE3EmBjG1xV50Db/I9Utw6HvNedHHQdPEj1ev bnCsu85kEjQRe3JPLJnzACZc7AnE94u2eBx0EDePajnWJNNvzBS14MzJP6AadosXjyJ7FyPdVpw qefYSZ0XDe7tLZ/jz2X6Hwud3YRmCX/jtmRTwjwZePw5TaPS0+9FMUTuPdpkmAMbSbbsOZLgv6W AqAdWKYOAbfpSFhXjIkLmQxVm+z0U7NQWLmzfEAjWS7f9j2vQDVFMjISJrwdVPDV1KyaQmCD1ru jPBJ07NuZ3n4FGYi1bVKDdz0WZ6q1WVtCoTWp9+VkJ4ZVeZCetnlonNTLhxOINGtsNFDhS+aIKv kjY2Z4JbjTGZCgsT5DpXlVGRwMNHqh73IZTnkgEp3lXhxsmxsCXh6ZVYPSePT1wUe1NYtkcgfIR 9RHutNBUQRlm/W5gzbhoHhrR4gCndUPiUNfixz7n5Pbdk2hOYcCQd/eSFci2B3H7hmYuFNYSNou FxXLQdAhp2FVED0ZTr5TyfxwvM1mUKvakNHVQ== X-Received: by 2002:a05:6820:2908:b0:6aa:f61e:2463 with SMTP id 006d021491bc7-6acb603b4f1mr8979eaf.24.1785334933143; Wed, 29 Jul 2026 07:22:13 -0700 (PDT) Received: from ?IPV6:2600:1700:e321:62f0:da43:aeff:fecc:bfd5? ([2600:1700:e321:62f0:da43:aeff:fecc:bfd5]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-4588646ade0sm2426214fac.5.2026.07.29.07.22.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 29 Jul 2026 07:22:12 -0700 (PDT) Sender: Guenter Roeck Message-ID: Date: Wed, 29 Jul 2026 07:22:10 -0700 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: [hwmon-next PATCH v4 3/4] hwmon: (adt7470) Expose fan control via PWM framework To: =?UTF-8?Q?Uwe_Kleine-K=C3=B6nig?= Cc: Luiz Angelo Daros de Luca , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Chris Packham , Andrew Morton , "Darrick J. Wong" , linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org References: <20260729-adt7470_thermalzone-v4-0-c14039dfa0e6@gmail.com> <20260729-adt7470_thermalzone-v4-3-c14039dfa0e6@gmail.com> <12dfeaae-f806-4adc-95f1-97fe10ef748e@roeck-us.net> Content-Language: en-US From: Guenter Roeck Autocrypt: addr=linux@roeck-us.net; keydata= xsFNBE6H1WcBEACu6jIcw5kZ5dGeJ7E7B2uweQR/4FGxH10/H1O1+ApmcQ9i87XdZQiB9cpN RYHA7RCEK2dh6dDccykQk3bC90xXMPg+O3R+C/SkwcnUak1UZaeK/SwQbq/t0tkMzYDRxfJ7 nyFiKxUehbNF3r9qlJgPqONwX5vJy4/GvDHdddSCxV41P/ejsZ8PykxyJs98UWhF54tGRWFl 7i1xvaDB9lN5WTLRKSO7wICuLiSz5WZHXMkyF4d+/O5ll7yz/o/JxK5vO/sduYDIlFTvBZDh gzaEtNf5tQjsjG4io8E0Yq0ViobLkS2RTNZT8ICq/Jmvl0SpbHRvYwa2DhNsK0YjHFQBB0FX IdhdUEzNefcNcYvqigJpdICoP2e4yJSyflHFO4dr0OrdnGLe1Zi/8Xo/2+M1dSSEt196rXaC kwu2KgIgmkRBb3cp2vIBBIIowU8W3qC1+w+RdMUrZxKGWJ3juwcgveJlzMpMZNyM1jobSXZ0 VHGMNJ3MwXlrEFPXaYJgibcg6brM6wGfX/LBvc/haWw4yO24lT5eitm4UBdIy9pKkKmHHh7s jfZJkB5fWKVdoCv/omy6UyH6ykLOPFugl+hVL2Prf8xrXuZe1CMS7ID9Lc8FaL1ROIN/W8Vk BIsJMaWOhks//7d92Uf3EArDlDShwR2+D+AMon8NULuLBHiEUQARAQABzTJHdWVudGVyIFJv ZWNrIChMaW51eCBhY2NvdW50KSA8bGludXhAcm9lY2stdXMubmV0PsLBgQQTAQIAKwIbAwYL CQgHAwIGFQgCCQoLBBYCAwECHgECF4ACGQEFAmgrMyQFCSbODQkACgkQyx8mb86fmYGcWRAA oRwrk7V8fULqnGGpBIjp7pvR187Yzx+lhMGUHuM5H56TFEqeVwCMLWB2x1YRolYbY4MEFlQg VUFcfeW0OknSr1s6wtrtQm0gdkolM8OcCL9ptTHOg1mmXa4YpW8QJiL0AVtbpE9BroeWGl9v 2TGILPm9mVp+GmMQgkNeCS7Jonq5f5pDUGumAMguWzMFEg+Imt9wr2YA7aGen7KPSqJeQPpj onPKhu7O/KJKkuC50ylxizHzmGx+IUSmOZxN950pZUFvVZH9CwhAAl+NYUtcF5ry/uSYG2U7 DCvpzqOryJRemKN63qt1bjF6cltsXwxjKOw6CvdjJYA3n6xCWLuJ6yk6CAy1Ukh545NhgBAs rGGVkl6TUBi0ixL3EF3RWLa9IMDcHN32r7OBhw6vbul8HqyTFZWY2ksTvlTl+qG3zV6AJuzT WdXmbcKN+TdhO5XlxVlbZoCm7ViBj1+PvIFQZCnLAhqSd/DJlhaq8fFXx1dCUPgQDcD+wo65 qulV/NijfU8bzFfEPgYP/3LP+BSAyFs33y/mdP8kbMxSCjnLEhimQMrSSo/To1Gxp5C97fw5 3m1CaMILGKCmfI1B8iA8zd8ib7t1Rg0qCwcAnvsM36SkrID32GfFbv873bNskJCHAISK3Xkz qo7IYZmjk/IJGbsiGzxUhvicwkgKE9r7a1rOwU0ETofVZwEQALlLbQeBDTDbwQYrj0gbx3bq 7kpKABxN2MqeuqGr02DpS9883d/t7ontxasXoEz2GTioevvRmllJlPQERVxM8gQoNg22twF7 pB/zsrIjxkE9heE4wYfN1AyzT+AxgYN6f8hVQ7Nrc9XgZZe+8IkuW/Nf64KzNJXnSH4u6nJM J2+Dt274YoFcXR1nG76Q259mKwzbCukKbd6piL+VsT/qBrLhZe9Ivbjq5WMdkQKnP7gYKCAi pNVJC4enWfivZsYupMd9qn7Uv/oCZDYoBTdMSBUblaLMwlcjnPpOYK5rfHvC4opxl+P/Vzyz 6WC2TLkPtKvYvXmdsI6rnEI4Uucg0Au/Ulg7aqqKhzGPIbVaL+U0Wk82nz6hz+WP2ggTrY1w ZlPlRt8WM9w6WfLf2j+PuGklj37m+KvaOEfLsF1v464dSpy1tQVHhhp8LFTxh/6RWkRIR2uF I4v3Xu/k5D0LhaZHpQ4C+xKsQxpTGuYh2tnRaRL14YMW1dlI3HfeB2gj7Yc8XdHh9vkpPyuT nY/ZsFbnvBtiw7GchKKri2gDhRb2QNNDyBnQn5mRFw7CyuFclAksOdV/sdpQnYlYcRQWOUGY HhQ5eqTRZjm9z+qQe/T0HQpmiPTqQcIaG/edgKVTUjITfA7AJMKLQHgp04Vylb+G6jocnQQX JqvvP09whbqrABEBAAHCwWUEGAECAA8CGwwFAmgrMyQFCSbODQkACgkQyx8mb86fmYHlgg/9 H5JeDmB4jsreE9Bn621wZk7NMzxy9STxiVKSh8Mq4pb+IDu1RU2iLyetCY1TiJlcxnE362kj njrfAdqyPteHM+LU59NtEbGwrfcXdQoh4XdMuPA5ADetPLma3YiRa3VsVkLwpnR7ilgwQw6u dycEaOxQ7LUXCs0JaGVVP25Z2hMkHBwx6BlW6EZLNgzGI2rswSZ7SKcsBd1IRHVf0miwIFYy j/UEfAFNW+tbtKPNn3xZTLs3quQN7GdYLh+J0XxITpBZaFOpwEKV+VS36pSLnNl0T5wm0E/y scPJ0OVY7ly5Vm1nnoH4licaU5Y1nSkFR/j2douI5P7Cj687WuNMC6CcFd6j72kRfxklOqXw zvy+2NEcXyziiLXp84130yxAKXfluax9sZhhrhKT6VrD45S6N3HxJpXQ/RY/EX35neH2/F7B RgSloce2+zWfpELyS1qRkCUTt1tlGV2p+y2BPfXzrHn2vxvbhEn1QpQ6t+85FKN8YEhJEygJ F0WaMvQMNrk9UAUziVcUkLU52NS9SXqpVg8vgrO0JKx97IXFPcNh0DWsSj/0Y8HO/RDkGXYn FDMj7fZSPKyPQPmEHg+W/KzxSSfdgWIHF2QaQ0b2q1wOSec4Rti52ohmNSY+KNIW/zODhugJ np3900V20aS7eD9K8GTU0TGC1pyz6IVJwIE= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 7/29/26 04:49, Uwe Kleine-König wrote: > On Tue, Jul 28, 2026 at 10:56:04PM -0700, Guenter Roeck wrote: >> On 7/28/26 21:46, Luiz Angelo Daros de Luca wrote: >>> The ADT7470 features four PWM outputs designed to control fans. >>> Previously, these were only accessible through the legacy hwmon >>> sysfs interface. >>> >>> Expose the ADT7470 fan control lines through the generic PWM framework. >>> This allows generic PWM consumers described in Device Tree, such as >>> "pwm-fan", to use the device through the "#pwm-cells" property. This is >>> particularly necessary for boards where the ADT7470 external temperature >>> sensors are not populated and the chip is used strictly as a fan >>> controller (e.g., Edgecore ECS-2100-52T switches). In such setups, >>> delegating control to the generic PWM subsystem allows the kernel's >>> thermal framework to manage the fans based on unrelated temperature >>> zones, such as internal SoC sensors. >>> >>> When a PWM consumer applies a new PWM state, the driver automatically >>> switches the corresponding PWM channel to manual mode so that the >>> requested duty cycle takes effect. The duty cycle specified by the PWM >>> framework is internally converted to the 0-255 scale expected by the >>> hardware registers. >>> >>> The legacy sysfs interface remains unaffected and operates in parallel. >> >> No, I won't accept this. It has to be either or. A pwm channel modeled as pwm >> subsystem channel must not be visible via hwmon attributes. > > I didn't look in detail, but maybe my red line is a bit more lax. IMHO > it's not OK to be able to modify a setting that results from pushing > hwmon knobs using PWM operations or vice-versa. Switching between > exclusive use at runtime is IMHO ok. > It is my call to make, and my call is either-or to avoid confusion. Thanks, Guenter