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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5BBE9C001B0 for ; Sat, 1 Jul 2023 11:09:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229846AbjGALJg (ORCPT ); Sat, 1 Jul 2023 07:09:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33428 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229530AbjGALJe (ORCPT ); Sat, 1 Jul 2023 07:09:34 -0400 Received: from mail-lf1-x133.google.com (mail-lf1-x133.google.com [IPv6:2a00:1450:4864:20::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45EC13C07; Sat, 1 Jul 2023 04:09:33 -0700 (PDT) Received: by mail-lf1-x133.google.com with SMTP id 2adb3069b0e04-4f9fdb0ef35so4639458e87.0; Sat, 01 Jul 2023 04:09:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1688209771; x=1690801771; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=LyQo7oGCzL0q4nMHdOWsUgl2XzXKe7BOngdS1hsphWI=; b=MpzVOfkTDGXum05mEE1Aa8/iBIcGLFakyuf9yYZoTYeGHZXIZ16CO5E5H8jLQ9lyUY BhAOA/GGqNh3NEz45nHeZb1wJsqptZXbB0ZY19HUvc0cCo337TWu4OEYjlRpFPBSQEa8 3DvQ3sful+ygfpyRjqf9YU8nwUqQCq1OflOIThjnA39YC3EFgjgidkkreL1PcQBa56XX uoDVGeOA/Dha/OoKocTDMDJAJk/iz3E2+fl2KmZjgZjXePXEm1grGoWgMwxnSzVN93DF +VD1Y0buGkf0Ec1dk/ZOAHD74ITsKXHMFgA/T+ywwc6+b0wpKs3+Zj01lAX9tLo4lQLW HP+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688209771; x=1690801771; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=LyQo7oGCzL0q4nMHdOWsUgl2XzXKe7BOngdS1hsphWI=; b=B+8fSDQuZseJWyeh3zS6+p8XKFegF0A/zQHV/z65QoUKhR4GK587bbKlxy4/dexScF uIXOj6VZnfqPaHW/qx84QO46tHwcTmLFIidCNdcxnHX0gyFTRMzuqSyXd5xS0dNpiyeJ qfGlXpn7g25jiFQbkoy9Kf6PEVjlbIQf5N3PxMIpQjYaj4LYbvqnRPlJCThlVhWowKzx mtQDNSq1DCxyVBQlyA4SJEtQFwyiGeG8E8ZZUvGuEWp6QrwD0IcBSl5JDANvc/LYQPFd 7f2Ou9vfR4FyhZjUcxDQbqD5J6tkrSH8LKNERQPm6EkjtTMuWUy539/Uxpk1kPhI1dPP C8Hw== X-Gm-Message-State: ABy/qLYPuTNKo/PkGAaWZqkPgkrAHMTPuxM3w6HhiPB8xQaNmiKIkzEg ELBZey6HFRTKuGM2nI9XLy4Jo8DWXFo= X-Google-Smtp-Source: APBJJlFJBnGRzqT/F8NwRkkxu9Uzyos7FGd6xZUEAGWgt3eTPo2M8RsX63JR4a+zwEAn05FPhtSxBw== X-Received: by 2002:a05:6512:3991:b0:4f8:49a8:a0e2 with SMTP id j17-20020a056512399100b004f849a8a0e2mr4796943lfu.16.1688209771171; Sat, 01 Jul 2023 04:09:31 -0700 (PDT) Received: from [192.168.0.131] ([194.183.54.57]) by smtp.gmail.com with ESMTPSA id g7-20020ac25387000000b004f3945751b2sm3350944lfh.43.2023.07.01.04.09.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 01 Jul 2023 04:09:30 -0700 (PDT) Message-ID: <3e8e7834-fe0e-7e92-5472-cb9fd223980e@gmail.com> Date: Sat, 1 Jul 2023 13:09:28 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH v2 1/2] led: led-class: Read max-brightness from devicetree To: Astrid Rost , Andy Shevchenko , Krzysztof Kozlowski , Rob Herring , Pavel Machek , Lee Jones Cc: kernel@axis.com, linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org References: <20230630092248.4146169-1-astrid.rost@axis.com> <20230630092248.4146169-2-astrid.rost@axis.com> Content-Language: en-US From: Jacek Anaszewski In-Reply-To: <20230630092248.4146169-2-astrid.rost@axis.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Astrid, On 6/30/23 11:22, Astrid Rost wrote: > Add max-brightness in order to reduce the current on the connected LEDs. > Normally, the maximum brightness is determined by the hardware, and this > property is not required. This property is used to set a software limit. > It could happen that an LED is made so bright that it gets damaged or > causes damage due to restrictions in a specific system, such as mounting > conditions. Note that led-max-microamp should be preferably used, if it > is supported by the controller. > > Signed-off-by: Astrid Rost > --- > drivers/leds/led-class.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c > index 9255bc11f99d..ce652abf9336 100644 > --- a/drivers/leds/led-class.c > +++ b/drivers/leds/led-class.c > @@ -457,6 +457,10 @@ int led_classdev_register_ext(struct device *parent, > if (fwnode_property_present(init_data->fwnode, > "retain-state-shutdown")) > led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN; > + > + fwnode_property_read_u32(init_data->fwnode, > + "max-brightness", > + &led_cdev->max_brightness); > } > } else { > proposed_name = led_cdev->name; We have led-max-microamp for that and every LED class driver is supposed to calculate its max brightness level basing on it. -- Best regards, Jacek Anaszewski