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 X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE87FC433E4 for ; Mon, 27 Jul 2020 10:21:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A6A752074F for ; Mon, 27 Jul 2020 10:21:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727775AbgG0KVB (ORCPT ); Mon, 27 Jul 2020 06:21:01 -0400 Received: from jabberwock.ucw.cz ([46.255.230.98]:42094 "EHLO jabberwock.ucw.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726139AbgG0KVB (ORCPT ); Mon, 27 Jul 2020 06:21:01 -0400 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 004E01C0BD4; Mon, 27 Jul 2020 12:20:58 +0200 (CEST) Date: Mon, 27 Jul 2020 12:20:58 +0200 From: Pavel Machek To: Marek =?iso-8859-1?Q?Beh=FAn?= Cc: jacek.anaszewski@gmail.com, dmurphy@ti.com, linux-leds@vger.kernel.org Subject: Re: We have multicolor, but should we turn it into RGB? Message-ID: <20200727102058.GA16553@amd> References: <20200727084500.GA15237@amd> <20200727114048.32f36c59@dellmb.labs.office.nic.cz> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="XsQoSWH+UP9D9v3l" Content-Disposition: inline In-Reply-To: <20200727114048.32f36c59@dellmb.labs.office.nic.cz> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-leds-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org --XsQoSWH+UP9D9v3l Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > Multicolor is a bit too abstract. Yes, we can have > > Green-Magenta-Ultraviolet LED, but so far all the LEDs we support are > > RGB, and not even RGB-White or RGB-Yellow variants emerged. > >=20 > > Multicolor is not a good fit for RGB LED. It does not really know > > about LED color. In particular, there's no way to make LED "white". > >=20 > > Userspace is interested in knowing "this LED can produce arbitrary > > color", which not all multicolor LEDs can. > >=20 > > Proposal: let's add "rgb" to led_colors in > > drivers/leds/led-core.c, add corresponding device tree > > defines, and use that, instead of multicolor for RGB LEDs. > >=20 > > We really need to do that now; "white" stuff can wait. > >=20 > > RGB LEDs are quite common, and it would be good to be able to turn LED > > white and to turn it into any arbitrary color. It is essential that > > userspace is able to set arbitrary colors, and it might be good to > > have that ability from kernel, too... to allow full-color triggers. >=20 > I am not against adding RGB if you want to somehow teach the subsystem > to mix arbitrary color (either by teaching it color curves or some > other way). But I think we shouldn't remove multicolor, and here's the > reason why: I'd not remove multicolor. It would be still there for non-RGB uses. (Sorry if I was unclear). But I may want to disable it for now, not to have ABI incompatibility in future. > Most of the time I have seen 2 LEDs per ethernet port, green and yellow, > but some ports have 2 Bi-Color LEDs, each consisting of green and > yellow. I think most of the time these are 2-terminal LEDs. >=20 > So basically here we have, instead of a RGB LED, a GY LED (GY for > green/yellow). =2E.. > So if we want to reasonably add support for this configuration of LEDs > and to offer the user to configure these DUAL modes via the trigger > API, I think these LEDs should be shown in the system as multicolor > LEDs. Yes, I guess multicolor may make sense there. Best regards, Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --XsQoSWH+UP9D9v3l Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAl8eqooACgkQMOfwapXb+vI4pwCfVO9jWq2uQC6Wmxr95Wundjwz gEMAoLXj55GKMdOasG/hTpPAlVoKOf+q =X0xg -----END PGP SIGNATURE----- --XsQoSWH+UP9D9v3l--