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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,URIBL_DBL_ABUSE_MALW, USER_AGENT_MUTT autolearn=ham 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 85F3FC433F4 for ; Fri, 21 Sep 2018 22:18:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B4D32159D for ; Fri, 21 Sep 2018 22:18:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2B4D32159D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ucw.cz Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726208AbeIVEJH (ORCPT ); Sat, 22 Sep 2018 00:09:07 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:60371 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726004AbeIVEJH (ORCPT ); Sat, 22 Sep 2018 00:09:07 -0400 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 512) id B47D380724; Sat, 22 Sep 2018 00:18:13 +0200 (CEST) Date: Sat, 22 Sep 2018 00:18:13 +0200 From: Pavel Machek To: Jacek Anaszewski Cc: Baolin Wang , rteysseyre@gmail.com, Bjorn Andersson , Mark Brown , Linus Walleij , Linux LED Subsystem , LKML Subject: Re: [PATCH v12 1/2] leds: core: Introduce LED pattern trigger Message-ID: <20180921221813.GA20355@amd> References: <67ebebf02edd6d8ee42a13b139733e9cc680ea86.1536631975.git.baolin.wang@linaro.org> <324778a9-a32c-ae6e-337a-39845f214bfc@gmail.com> <20180921211758.GC18062@amd> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="bg08WKrSYDhXBjb5" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --bg08WKrSYDhXBjb5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat 2018-09-22 00:11:29, Jacek Anaszewski wrote: > On 09/21/2018 11:17 PM, Pavel Machek wrote: > > On Fri 2018-09-21 22:59:40, Jacek Anaszewski wrote: > >> Hi Baolin, > >> > >> On 09/21/2018 05:31 AM, Baolin Wang wrote: > >>> Hi Jacek and Pavel, > >>> > >>> On 11 September 2018 at 10:47, Baolin Wang w= rote: > >>>> This patch adds one new led trigger that LED device can configure > >>>> the software or hardware pattern and trigger it. > >>>> > >>>> Consumers can write 'pattern' file to enable the software pattern > >>>> which alters the brightness for the specified duration with one > >>>> software timer. > >>>> > >>>> Moreover consumers can write 'hw_pattern' file to enable the hardware > >>>> pattern for some LED controllers which can autonomously control > >>>> brightness over time, according to some preprogrammed hardware > >>>> patterns. > >>>> > >>>> Signed-off-by: Raphael Teysseyre > >>>> Signed-off-by: Baolin Wang > >=20 > >>> Do you have any comments for the v12 patch set? Thanks. > >> > >> We will probably have to remove hw_pattern from ledtrig-pattern > >> since we are unable to come up with generic interface for it. > >> Unless thread [0] will end up with some brilliant ideas. So far > >> we're waiting for Pavel's reply. > >> > >> [0] https://lkml.org/lkml/2018/9/13/1216 > >=20 > > To paint a picture: > >=20 > > brightness > >=20 > > rise hold lower hold down > > ^ XXXXXXXXXXXXXXX > > | X XX > > | X XX > > | X XXXXXXXXXXXXXXXXXXXXXXXXXX > > +-------------------------------------------------------> time > >=20 > > This is what Baolin's hardware can do, right? > >=20 > > This is also what pattern trigger can do, right? > >=20 > > So all we need to do is match the two interfaces, so that hw_pattern > > returns -EINVAL on patterns hardware can not actually do. > >=20 > > I believe I described code to do that in [0] above. >=20 > You said that we should get the same effect by writing the > same series of tuples to either pattern or hw_pattern file. >=20 > Below command consists of four tuples (marked with brackets > to highlight), and it will activate breathing mode in Baolin's > hw_pattern: >=20 > "[0 rise_duration] [brightness high_duration] [brightness fall_duration] > [0 low_duration]" >=20 > Now, I can't see how these four tuples could force the software > fallback to produce breathing effect you depicted. I really should get some sleep now. But my intention was that software fallback produces just that with those four tuples. (If it does not, we can fix the software fallback to do just that). Best regards, Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --bg08WKrSYDhXBjb5 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlulbiUACgkQMOfwapXb+vLpaACggmR+oeYCbtw3v9Gq/QnUSUFq lSwAnRdIJvbgzFlxnLLnybXGAVRjwiLP =DfIo -----END PGP SIGNATURE----- --bg08WKrSYDhXBjb5--