From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 D52A81DD0EF; Sun, 13 Sep 2026 02:51:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789267896; cv=none; b=KhDNFvqsMt7rvHtL54nxmcFdnoMuYNY2InaKne635k/azQZMdDHq6lm/rffxHYj7oix5ddR5Rj215CAA9ch4HmJ4xye33nOVkf0SGwasjv00c402CeUjgiEdJRCA5WaAJsZ9SRG+dsx15K5zXsveqLqCMF+N60k/FMAOrc3H/bI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789267896; c=relaxed/simple; bh=odRcFUf8WOt2n1xjeZqHL3deYBqqqBZIorReFaAbSXE=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=fPQiOeS/iLTYfsKvYFLliTEYChbugzCN4co+AWdO64Mc9A/00D6gMu/DbnTjSjfWKsJZXv4TwlGhmSet0qz22g9ejdvjkRODMS+b4GoquLYzar5Rwuz+auy4UpzmfL0yYc5PnX2k4/RvLcMmF4hID29BV3myVb/gKRLmOEuRljI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Z+6nKiT0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Z+6nKiT0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84FA21F000FF; Sun, 13 Sep 2026 02:51:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789267895; bh=69FABYPOsdqsJNrLJcIOfj7YCLyrYCIw0DIwc2sain4=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=Z+6nKiT0K1LpLMqP9RvAlqZbbkRXX3zY+FuH/raaT05s8wuzNQPQwa6HpitqC7Ra/ C5tYAF/Mx0nWikfbHiuwMm/X4K9W72Z6K/tix5oJo7twR2XOanw3rFWayP+pdLzrGl nZY9Kmb9Kp8s1u6ZKY4qqwc5LJnM4167OB+DD9Q8By6OR34/3YIWx4N9nfi0KAvxWJ gpYQp3VtxMsACJyk4DIflk3QG+PG/1GX3NOqboHifKyKyXFe1NQi86O5MQs7lqFDUV q0YbEdmJ8cjuS/JM9m/hlZkdMrVcmTgNY+/su8fXwjnjSBxjXHyGi1/y/vt4ikqoBd yv9Py0iOPIVmw== Date: Sun, 13 Sep 2026 03:51:32 +0100 From: Jonathan Cameron To: Chang Yu Cc: Andy Shevchenko , David Lechner , Nuno =?UTF-8?B?U8Oh?= , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Shi Hao , "Jose A. Perez de Azpillaga" , Joshua Crofts , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 1/2] dt-bindings: iio: light: add as7343 Message-ID: <20260913035132.1fb50e6e@jic23-hlaptop> In-Reply-To: References: <20260912013912.51887-1-marcus.yu.56@gmail.com> <20260912013912.51887-2-marcus.yu.56@gmail.com> <20260913015652.029475d2@jic23-hlaptop> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 12 Sep 2026 18:35:14 -0700 Chang Yu wrote: > Hi Jonathan, > > A quick comment inline. > > On Sun, Sep 13, 2026 at 01:56:52AM +0100, Jonathan Cameron wrote: > > On Fri, 11 Sep 2026 18:39:11 -0700 > > Chang Yu wrote: > > > > > + description: > > > + The driver current for the external LED connected to the LDR pin. > > > + minimum: 4000 > > > + maximum: 258000 > > > + multipleOf: 2000 > > > + default: 12000 > > > + > > > + sync-gpios: > > > + description: | > > > + Optional GPIO pin that can be used either as a synchronization input to > > > + start/stop measurement or as an external start/stop signal for > > > + synchronizing with the connected LED. > > > > So the datasheet starts referring to using this for some level of sync > > but then only actually treats it as as a gpio (maybe I'm missing something). > > Any idea what that stuff about start/stop is talking about? > > > > The only thing I can find about this is the device diagram in figure 13 that has the GPIO > > wired to the led driver and the automatic measurement engine. > > > That's what I got from the datasheet as well. They don't describe how to > use the GPIO pin to perform synchronizations at all. > > The adafruit arduino driver > (https://github.com/adafruit/Adafruit_AS7343/blob/main/Adafruit_AS7343.cpp) > is slightly more helpful - the GPIO in output mode signals when the > spectral measurement starts. Unfortunately no information about input > mode. There is no separate control? If so we can't use it as a GPIO as whilst there is a control to set the state it will randomly get overwritten if we do such a read. So to me sounds like that is there for testing the connection and similar usecases only and we should not expose this as a GPIO. Maybe input is possible but that may also have side effects. So I'd be tempted to drop it from the binding - with some description of why it is not there in the patch description. > > > > + maxItems: 1 > > > + > > > +required: > > > + - compatible > > > + - reg > > > + - vdd-supply > > > + > > > +additionalProperties: false > > > > >