From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacek Anaszewski Subject: Re: [PATCH] leds: pca9532: Extend pca9532 device tree support Date: Thu, 9 Feb 2017 22:10:21 +0100 Message-ID: <7aef407c-3b85-a18a-c19d-72545211a4cc@gmail.com> References: <725c338e-af4c-1332-6c27-462c2dc1b97f@gmail.com> <3bfc9206-18c7-470b-ca53-d7bdb9a34f0a@ltec.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Received: from mail-wr0-f194.google.com ([209.85.128.194]:33286 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753227AbdBIVTU (ORCPT ); Thu, 9 Feb 2017 16:19:20 -0500 In-Reply-To: <3bfc9206-18c7-470b-ca53-d7bdb9a34f0a@ltec.ch> Sender: linux-leds-owner@vger.kernel.org List-Id: linux-leds@vger.kernel.org To: Felix Brack , riku.voipio@iki.fi, rpurdie@rpsys.net, pavel@ucw.cz, linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org Cc: f.brack@eets.ch Hi Felix, On 02/09/2017 09:41 AM, Felix Brack wrote: > Hello Jacek, > > On 08.02.2017 20:42, Jacek Anaszewski wrote: >> Hi Felix, >> >> On 02/08/2017 05:12 PM, Felix Brack wrote: >>> Hello Jacek, >>> >>> On 07.02.2017 21:45, Jacek Anaszewski wrote: >>>> Hi Felix, >>>> >>>> Thanks for the patch. >>>> >>>> On 02/07/2017 07:11 PM, Felix Brack wrote: >>>>> This patch extends the device tree support for the pca9532 allowing LEDs to blink, dim or even being unchanged, i.e. not being turned off during driver initialization. >>>> >>>> Isn't it possible to apply desired settings with existing LED subsystem >>>> brightness file, and delay_on/off files exposed by timer trigger? >>>> >>>> Best regards, >>>> Jacek Anaszewski >>>> >>> >>> This might be a misunderstanding. My patch is not meant to replace >>> anything for driving the LEDs once the kernel is fully loaded. The LED >>> subsystem offers quite a lot of possibilities to do this. >>> >>> My patch mainly deals with the 'default' state of the LEDs immediately >>> when the driver gets loaded. >>> Here is an example: I have a system with a LED named 'RUN' which is >>> turned on steady by U-Boot (indicating "system booting"). When the >>> PCA9532 driver loads this LED gets turned off due to initialization. >>> However I would like it remain lit until later a script will make that >>> 'RUN' LED blink (indicating "system running"). This script will of >>> course use the existing LED subsystem to do so. To keep the 'RUN' LED >>> lit I need the DT property 'default-state' being set to 'PCA9532_KEEP'. >> >> It looks like all you need is default-state property. > > For the example with keeping the 'RUN' led turned on, yes. However I > would have to configure PSC and PWM registers to make the 'RUN' LED > blink, for example. > >> I'd rather avoid exposing prescaler and pwm registers in DT. > > I don't see that exposing PSC and PWM registers to the DT would do any > harm. Is there something I'm missing here? It is driver's responsibility to configure registers basing on user settings. Let's stick to this scheme. -- Best regards, Jacek Anaszewski