From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f53.google.com (mail-wm1-f53.google.com [209.85.128.53]) (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 90BC93AFAE4 for ; Thu, 27 Aug 2026 22:26:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787869568; cv=none; b=UTxYosb6TIVow5kH/8P9l4JHfr2VSWEf0VXy0rtrdecClRlnDU36hg5atvLcB8b648BFEADgC2xoNftfqClvdMemsuLJrgZAOPL+Seo54bEXSBl4yfWVXrZEM49xhoXHStPd6Jzx6XIBSLJj5eS+8pWEUD5rbVDHaN+SyXmQuDs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787869568; c=relaxed/simple; bh=TxvaZ4zayK7a2B63L4t8D8MbZm8/BwjOSwYLxeyM8RU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MENqJPGCqQNrBJuXtrIdLJQDr0lj6ksTBk32PNRvjsz4WRFfg/H7C4l/ofQe3FezxP9K/y1CD/vMqLmEvZ2ZfFqPsTGur6KGIExPC3WtheU+RPUxE/1MT7UzR1KmcDNZGUFUgxP4YGnqWInFqL1f0G79eCzaKJiFtKt7SoVraYc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=IF5KNcA6; arc=none smtp.client-ip=209.85.128.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com 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="IF5KNcA6" Received: by mail-wm1-f53.google.com with SMTP id 5b1f17b1804b1-49b0d78a801so2157675e9.2 for ; Thu, 27 Aug 2026 15:26:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1787869559; x=1788474359; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=KrToZPBnqDhx/hwRhT5E5yIhfEGUpGAvOCdqzL7a7pQ=; b=IF5KNcA61mCdmQAodnOMCbggzzV5GrSxVQCEGQJCGP+SqnY/CbBiUNQpPohcXta6/K NJe2uIl9cAqkhldVJeP/RHrhRUn7yJKKMjLsSzx6+PUyVtYqxVPTOjVnksM7d+0IGS5N IOyTXSpEAjSHBLhgHkzxOKK4VpjTVLgm5rFiOo6d3Q/2pR5ckLDRn7RPbDRdf0QnPl40 qUueiIgrMI2dGZREPRUnf/e0U85r4aBQ+P5obu1ijGNY2ipD6EV8sK0/Ag/aXn4IuANN 3u7T3fs+tvg9It+W2/9VvHMwu1q3C4af4S5GFVgrQ/LQ2j4Npi+T1zwbe2IKpmj58hOY JfOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787869559; x=1788474359; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=KrToZPBnqDhx/hwRhT5E5yIhfEGUpGAvOCdqzL7a7pQ=; b=bSw/6NdQWGARH9PxS9cZ7ASp1wX7QM06KCaGHko/ScnuprUJQEvcCEMA2+iddMMiji SPw+maawX4Ow3GuadxaIA6lHkHZWDrhOKjzCtdadRj7eUNQHAnODUgpGrdoReYCKxlUc Vi0GDXJGPW96vXBqA56z64iz8lCuR2XsNl1w5E7v/m7RTkdA5I68Dl4DmbA11CYVoZXO e65f4Y88oaNViGvdxpm9M3Ggu5/wJ2m9DPrlWhqnod8lW7odoIrA8cmFHCeOSp+I/m51 qh4ZX+u+e51e0kejf+B/Qq9V6Z5o+E/vkZT2v9cRwuXfPHW+I0NoEv/Zqumo4SYg9qVu 13uA== X-Forwarded-Encrypted: i=1; AHgh+RqnGqmC+qgLCVcb0SxLI8d1tCjqgWiWkcDLVhbsFBAQxh/1944HN7xfOLHlGi9gp0lRUj5cC9FzBr5r1u8=@vger.kernel.org X-Gm-Message-State: AFuF++mLz8i4opdF19SYw/D63BPLgoeFWX0rgSvuzyZazppkFfzfj3sv Aq+Xe4np8LWrDRIIlJ+NbQBun0na1CYe4QkD99aduCDQ5A3TmtLr1FoK X-Gm-Gg: AR+sD13oAzTzzGHLeLy5DTWERFAry6E+5JjH7O3XKB6oKCM1+oHievxEZQPBcprV15K 6L5T5Y/2YNqRgGtGb4JTlHg1+12w1W8jBFc3Goe38UxArlmkxnEBJCAwzxKKLlcRi9yaqDp4fso gmiZNmeGg8VfI03YB3+5csYDSSDBU4delAtHqPsf0R07eYO0vTwio0qDVd+hlMYZdIHfkoLj/2F 15NdwoLFVrmW/eRE1M1UhYIzr0qc32ILq89WCHJqfo6s6vTpRoLO4+moHiW1gBvk71RcZRHu+lA R8v9AjDmS0nAmsvBx0FbEQIgiJt4EBMGQEq4Y9eK01Ik1r1qQg0/gVi+ORPTUhsA4/WFnNZllRQ JDN1m6qNmx378MZ4M4g2w8altTXT6Z0fGQGKxkbCIjCV9x4nRgFmhJmgFySdKNpL6ICtiEIa3n8 sJs/JD39h3yrJJwm19l69m1A74igWhvJ99rxR98wIUv5fxPj5tjl2YTMWPUD4= X-Received: by 2002:a05:600c:698c:b0:499:adb5:e7b2 with SMTP id 5b1f17b1804b1-49b91c3ddc7mr38429415e9.11.1787869558933; Thu, 27 Aug 2026 15:25:58 -0700 (PDT) Received: from m2.. ([37.142.156.156]) by smtp.googlemail.com with ESMTPSA id 5b1f17b1804b1-49b494228bfsm79722395e9.2.2026.08.27.15.25.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 Aug 2026 15:25:58 -0700 (PDT) From: Michael Zaidman To: lee@kernel.org Cc: linusw@kernel.org, jikos@kernel.org, bentiss@kernel.org, brgl@kernel.org, linux-input@vger.kernel.org, linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 00/13] HID: ft260: add UART and GPIO support, plus I2C fixes Date: Fri, 28 Aug 2026 01:25:50 +0300 Message-ID: <20260827222550.24634-1-michael.zaidman@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260827205116.GJ2943942@google.com> References: <20260827205116.GJ2943942@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Thu, 27 Aug 2026 at 21:51 +0100, Lee Jones wrote: > That's precisely what MFD is. It's one chip, usually with a shared and > overlapping register spaces, that conducts multiple functions. This is > no different to any other single-chip device or SoC. > > Shoving everything into a single driver isn't how things are done in > Linux. This should be divided up into the associated sub-systems where > each part can be reviewed and looked after by the appropriate SMEs. Understood, and I am not going to argue MFD scope with you. But this is not specific to my series, so I would rather not decide it here on my own. drivers/hid already registers other subsystems' devices from a hid_driver: hid-cp2112 adds an i2c_adapter and a gpiochip, hid-mcp2221 adds an i2c_adapter, a gpiochip and an IIO device, and hid-ft260 has hosted the I2C adapter since v5.13, commit 6a82582d9fa4 ("HID: ft260: add usb hid to i2c host bridge driver"). So the split you are asking for is not a change to this series. It means moving code that has been in drivers/hid since v5.13 into an MFD parent with cells, and the same reasoning would apply to cp2112 and mcp2221. I am willing to discuss that as its own conversion, but it needs the HID maintainers to agree on the direction first, and I do not think the UART and GPIO support should wait behind it. It would also spread the driver over four trees, so a fix touching the shared chip state becomes a cross-tree series with coordinated merges between four maintainers - a cost the single driver does not have. Jiri, Benjamin - this is your call. Do you want FT260 functionality to keep growing inside hid-ft260, as cp2112 and mcp2221 do today, or do you want a drivers/hid to MFD conversion for this class of USB HID bridge chips? Thanks, Michael