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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 08F60C10F14 for ; Sun, 6 Oct 2019 04:06:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D3B0221871 for ; Sun, 6 Oct 2019 04:06:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kryo-se.20150623.gappssmtp.com header.i=@kryo-se.20150623.gappssmtp.com header.b="jZqezZwx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725298AbfJFEGl (ORCPT ); Sun, 6 Oct 2019 00:06:41 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:55795 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725899AbfJFEGl (ORCPT ); Sun, 6 Oct 2019 00:06:41 -0400 Received: by mail-wm1-f67.google.com with SMTP id a6so9221264wma.5 for ; Sat, 05 Oct 2019 21:06:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kryo-se.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+uS9Iq71Nly9kmaIRhpKoadRKleDiTGevpR+ZqAHZYs=; b=jZqezZwxlS1YPn3bnr2v8C+R//3noxn9wJo0ifbD3Awy0DneqE5CfAYeBsGAxQXEcg z9VfNYXAYUKjzl2IBtO6LXg42/mObp6PzhkYUSpzhvf++owcp3wd8PzQ50LJfqeyQwpm v9+TWTvTee7WGOhUSjJkTdjf92a3G41x+SycJ+a906UaXjpn6Gc+2RwVpPVKzGjD/ong LP1Kz452WqGEHAC+JGjeunFW/jq3BTTgNj5+l8Z9kZxn2tMlcjo/zjDcW69BMfCn/tT2 CbEJKuDyrQo4eznCf6XYm4NMIZ0J87Qq9Ylr5qW3IbWP7vEGqLAX1/4TbKcDEQVRSEjF 4vlw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=+uS9Iq71Nly9kmaIRhpKoadRKleDiTGevpR+ZqAHZYs=; b=gGuFVBLpoSVu3Zkh4p+3TGbz102mWvTEDAtNH6upenfK13RiSdncdw+hV/an37sRsx 1onMLX0BTbevncLnR3PJodzd4h8a8kBn1sVs99CGqEsF+miaKJ/sM3x95UtqKHx5vRMc eXOIJcuN7ZIjB+7a7RenhwixnSwFsbrbLLiWELNFziFv11qSFhIeJOEIWhAwcxFusp6M fhq7fLMJCIXl2Ah5ItLOsVODPt+P0LPHdYyjnZW3goTYUWRlE3gIoHHVymKGd5WDZYK/ uNNPF2wK9Xt55s95GjTymONDw0pCSdzJSB1g0ldW1PHVo5v4+Dm2/aKHPx2/UORuYIof 9qrQ== X-Gm-Message-State: APjAAAUv/BpWWCw/1evCBOK2R9MbaKD4L+xB9EMk64W1z1mV6m5U4gmD AEv9+sOEHELKuZSKJDp5QKXSHGTeIPQHuqfCux9cOg== X-Google-Smtp-Source: APXvYqzEjmlx23LtZHhnO3vtMsvETtbJjdLbCfcHSKDCsRMmSQBSg9oiIqS4iPSDy8osUQPM2B4w3iaWv7ryaF8Pm2M= X-Received: by 2002:a7b:c8c3:: with SMTP id f3mr15381822wml.157.1570334798953; Sat, 05 Oct 2019 21:06:38 -0700 (PDT) MIME-Version: 1.0 References: <1570203299-4270-1-git-send-email-akinobu.mita@gmail.com> In-Reply-To: <1570203299-4270-1-git-send-email-akinobu.mita@gmail.com> From: Bjorn Andersson Date: Sat, 5 Oct 2019 21:06:27 -0700 Message-ID: Subject: Re: [PATCH] leds: gpio: support multi-level brightness To: Akinobu Mita Cc: Linux LED Subsystem , linux-gpio@vger.kernel.org, Linus Walleij , Bartosz Golaszewski , Jacek Anaszewski , Pavel Machek , Dan Murphy Content-Type: text/plain; charset="UTF-8" Sender: linux-leds-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org On Fri, Oct 4, 2019 at 8:35 AM Akinobu Mita wrote: > > Currently, GPIO LED driver allows the GPIO properties to contain one GPIO > phandle. This enables to contain more than one GPIO phandle and the > brightness of the LEDs is proportional to the number of active GPIOs. > > Describing multi-level brightness GPIO LED is only supported in DT. It is > not supported in ACPI and platform data. > This looks interesting. I have a half-baked driver for the NXP PCA9956B; which is a 24-channel LED driver, each channel with brightness control. With these LEDs mounted in a line (like on my devboard), an interface for setting e.g. a percentage and have the appropriate number of LEDs light up seems like an interesting thing to pursue. So I think this would be better represented in some more generic form, perhaps a trigger? Regards, Bjorn