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=-4.0 required=3.0 tests=BAYES_00, 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 8532EC433E1 for ; Fri, 14 Aug 2020 17:23:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 68B2920774 for ; Fri, 14 Aug 2020 17:23:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728413AbgHNRXY (ORCPT ); Fri, 14 Aug 2020 13:23:24 -0400 Received: from honk.sigxcpu.org ([24.134.29.49]:47860 "EHLO honk.sigxcpu.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727894AbgHNRXX (ORCPT ); Fri, 14 Aug 2020 13:23:23 -0400 Received: from localhost (localhost [127.0.0.1]) by honk.sigxcpu.org (Postfix) with ESMTP id 0B015FB03; Fri, 14 Aug 2020 19:23:22 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at honk.sigxcpu.org Received: from honk.sigxcpu.org ([127.0.0.1]) by localhost (honk.sigxcpu.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Cirbr_6XKokd; Fri, 14 Aug 2020 19:23:20 +0200 (CEST) Received: by bogon.sigxcpu.org (Postfix, from userid 1000) id 3D040457CC; Fri, 14 Aug 2020 19:23:20 +0200 (CEST) Date: Fri, 14 Aug 2020 19:23:20 +0200 From: Guido =?iso-8859-1?Q?G=FCnther?= To: Pavel Machek Cc: kernel list , linux-arm-kernel Subject: Re: Camera LED on Librem 5 was Re: [PATCH] backlight: add led-backlight driver Message-ID: <20200814172320.GA740513@bogon.m.sigxcpu.org> References: <20200219191412.GA15905@amd> <20200220082956.GA3383@bogon.m.sigxcpu.org> <20200220234151.GB1544@amd> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200220234151.GB1544@amd> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Pavel, On Fri, Feb 21, 2020 at 12:41:51AM +0100, Pavel Machek wrote: > Hi! > > > > This patch adds a led-backlight driver (led_bl), which is similar to > > > pwm_bl except the driver uses a LED class driver to adjust the > > > brightness in the HW. Multiple LEDs can be used for a single backlight. > > > > Tested-by: Guido Günther > > Thanks for testing! > > I noticed blog post about using Librem 5 torch. Unfortunately, it used > very strange/non-standard interface, first using LED as a GPIO to > enable LED controller, then direct i2c access. That is not acceptable > interface for mainline, and it would be better not to advertise such > code, as it will likely become broken in future. I agree, there's a driver for the lm3560 in media/ but how would one expose the torch part as a LED? It seems you hit something similar in https://lkml.org/lkml/2018/5/6/30 I also couldn't find an in tree driver that registers a flashlight as a v4l subdev. Did i miss that? Cheers, -- Guido