From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lelvem-ot01.ext.ti.com (lelvem-ot01.ext.ti.com [198.47.23.234]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A74A02206A5; Fri, 6 Dec 2024 18:02:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.23.234 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733508163; cv=none; b=nkf3ufB/RPar/28476g1fjXtEPhgZzeTeLt30++uxDCgapzCMSPRjRVWa8UeMke5qqXtaXYF5pKLemtlvt/H0tXuIdbZCEava6XixHdvPENs1wX0w7M5QcYJqtvQvnqUcXAqT8N0mZiUOXx3vKSjQuqQAc1MWOEdKfv7EYXgHpY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733508163; c=relaxed/simple; bh=GqPKbILJz1hkE4TVnKaZUB7g2QlHy4l2n9/flgVAakA=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=mXorUFOrXqJW/C9J8hjpH1wHgZttIEFNR68l101EyXt/TG05i0AZTFgqFhZeLl8PFr2kWAhae1sJBgULmQtoZtuO4MnLu9x1kg1GEQsCAwJj/d5YnJkgOj9OWGBNTqeXMTr0oKlcTCg9ryw7WFpDoulvi4MFQ7IeFvT7scMwIBw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com; spf=pass smtp.mailfrom=ti.com; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b=pppjbmu3; arc=none smtp.client-ip=198.47.23.234 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ti.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="pppjbmu3" Received: from lelv0265.itg.ti.com ([10.180.67.224]) by lelvem-ot01.ext.ti.com (8.15.2/8.15.2) with ESMTPS id 4B6I2HF52394970 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 6 Dec 2024 12:02:17 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1733508137; bh=AB7rvt8lEDFwJ8EFWXm4qm+/wdw4f6cHzb/xxrpxAas=; h=Date:Subject:To:CC:References:From:In-Reply-To; b=pppjbmu3TH0G3sPdDbHHVTipbIxzBMGBaOVTUtftpzsLbkyVI1fy8TsuSaWZPuiNH +uZGZAEwmzi+HyeAnvwdH/t5XRZeYzGjUTz6WKGcT/W9dEYrc7SsuvzRZAcPle1aQO ltm9DJVEFRwdLIPENozc4c6ENCE1T5o9wnoADPr8= Received: from DFLE114.ent.ti.com (dfle114.ent.ti.com [10.64.6.35]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 4B6I2HAL032754 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 6 Dec 2024 12:02:17 -0600 Received: from DFLE111.ent.ti.com (10.64.6.32) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Fri, 6 Dec 2024 12:02:17 -0600 Received: from lelvsmtp5.itg.ti.com (10.180.75.250) by DFLE111.ent.ti.com (10.64.6.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Fri, 6 Dec 2024 12:02:17 -0600 Received: from [10.249.42.149] ([10.249.42.149]) by lelvsmtp5.itg.ti.com (8.15.2/8.15.2) with ESMTP id 4B6I2GXk113376; Fri, 6 Dec 2024 12:02:16 -0600 Message-ID: Date: Fri, 6 Dec 2024 12:02:16 -0600 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] dt-bindings: backlight: Convert LP8860 into YAML format adding LP886x To: "Sverdlin, Alexander" , "conor@kernel.org" CC: "jingoohan1@gmail.com" , "dmurphy@ti.com" , "lee@kernel.org" , "dri-devel@lists.freedesktop.org" , "devicetree@vger.kernel.org" , "robh@kernel.org" , "pavel@ucw.cz" , "danielt@kernel.org" , "linux-leds@vger.kernel.org" , "krzk+dt@kernel.org" , "conor+dt@kernel.org" References: <20241206170717.1090206-1-alexander.sverdlin@siemens.com> <20241206170717.1090206-2-alexander.sverdlin@siemens.com> <20241206-brim-talcum-f5e8c504c572@spud> <129a3e14-9c87-47c2-b4ed-49bbcf12ae7e@ti.com> <1b8648f10248a949508240785f5a99ed7c2c2037.camel@siemens.com> Content-Language: en-US From: Andrew Davis In-Reply-To: <1b8648f10248a949508240785f5a99ed7c2c2037.camel@siemens.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-C2ProcessedOrg: 333ef613-75bf-4e12-a4b1-8e3623f5dcea On 12/6/24 11:46 AM, Sverdlin, Alexander wrote: > Hi Andrew, > > On Fri, 2024-12-06 at 11:43 -0600, Andrew Davis wrote: >>> Are you sure this is a correct thing to do? The lp8860-q1 product link >>> cites it as being a 4-channel device. Even if the kernel only ever >>> supports it as a single-channel device, the binding should reflect what >>> it is capable of doing. >>> >> >> Agree, the driver today just checks the first child node, but it could >> be extended for all 4 supported LED channels, and we shouldn't have >> to change the binding for that new support. > > but the channels are (in my understanding) for power-balancing only, there > are no separate controls for them. What do I miss? > I'm not very familiar with this part either, but looking at the datasheet I see: > Supports Display Mode (Global Dimming) and > Cluster Mode (Independent Dimming) > In Cluster mode LED strings have independent control but fewer features enabled than in Display Mode. And one channel controlling the others is only in this "Display Mode", but the currents to the others can be independently controlled in a different mode (seems these modes have less features which is probably why the driver doesn't make use of that today). Andrew