From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED988C7619A for ; Sat, 15 Apr 2023 08:01:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229794AbjDOIBL (ORCPT ); Sat, 15 Apr 2023 04:01:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229468AbjDOIBI (ORCPT ); Sat, 15 Apr 2023 04:01:08 -0400 Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A36D849D9; Sat, 15 Apr 2023 01:01:03 -0700 (PDT) Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id E46FF1C0AB2; Sat, 15 Apr 2023 10:01:01 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ucw.cz; s=gen1; t=1681545661; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=WKOfHFSvF51S8U0qAFTMc9vvwKSGDaBvGYYgvsZmZKk=; b=f35DJZ/DoxfHcrF57sYZx+sKCO5YSn1hBjHDRULqu06+4KkItkxlVG7Tqc+FKue+Ld3Tys QzSaIstNHFre9/DnDvFDXZMShGivGLvRkQ+xFzjuBLI0ZXH91bu/bhBX6TG0waHwRuNw9B vpxBCgYM5+Ve3fYqw5XwsAakjoMm3SQ= Date: Sat, 15 Apr 2023 10:01:02 +0200 From: Pavel Machek To: Andreas Kemnade Cc: lee@kernel.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Matti Vaittinen Subject: Re: [PATCH v4 2/2] leds: bd2606mvv: Driver for the Rohm 6 Channel i2c LED driver Message-ID: References: <20230414055341.335456-1-andreas@kemnade.info> <20230414055341.335456-3-andreas@kemnade.info> <20230415000533.534ea99b@aktux> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="HyL346m6DlBmbap6" Content-Disposition: inline In-Reply-To: <20230415000533.534ea99b@aktux> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --HyL346m6DlBmbap6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > > The device provides 6 channels which can be individually > > > turned off and on but groups of two channels share a common brightness > > > register. =20 > >=20 > > Yeah, well.. Turn it into 3-channel controller with brightness or > > 6-channel on/off one... You can't really share brightness. > >=20 > No, I cannot change the hardware, so it is a 6-channel with limitations. > And the devicetree has to describe the hardware and not the driver. Device tree is okay, I commented on the driver. > What is discussable is just how the driver should deal with that: >=20 > I see 5 possibilities. > a) ignore the shared brightness problem (status quo) > b) never set a brightness other than full on/off > c) ignore one led of each pair (not register it at all{ > d) couple also the on/off of the pairs, so present to > userspace only max. 3 leds. > e) allow full brightness control where independently possible, > if LEDs are defined where that leads to conflicts, > register them with max_brightness=3D1 and use them > in on/off mode. >=20 > My preference were a) or e), the most possible usages. > e) has a cleaner interface to the userspace. b) c) e) are acceptable to me. So I guess e) is preffered. BR, Pavel --=20 People of Russia, stop Putin before his war on Ukraine escalates. --HyL346m6DlBmbap6 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCZDpZvgAKCRAw5/Bqldv6 8mJmAJ9pkr4g+mUllXlalLoHux4zFB6q8ACfcm6tduTKgAhtq5v26sV7/2ZHxa4= =Vrcm -----END PGP SIGNATURE----- --HyL346m6DlBmbap6--