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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 AE2DCC432C0 for ; Thu, 21 Nov 2019 18:22:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8FA91206CB for ; Thu, 21 Nov 2019 18:22:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726293AbfKUSWd (ORCPT ); Thu, 21 Nov 2019 13:22:33 -0500 Received: from muru.com ([72.249.23.125]:43210 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726279AbfKUSWc (ORCPT ); Thu, 21 Nov 2019 13:22:32 -0500 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id A48D880DB; Thu, 21 Nov 2019 18:23:08 +0000 (UTC) Date: Thu, 21 Nov 2019 10:22:28 -0800 From: Tony Lindgren To: Rob Herring Cc: Jean-Jacques Hiblot , jacek.anaszewski@gmail.com, pavel@ucw.cz, sre@kernel.org, mark.rutland@arm.com, lee.jones@linaro.org, daniel.thompson@linaro.org, dmurphy@ti.com, linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, tomi.valkeinen@ti.com, devicetree@vger.kernel.org Subject: Re: [PATCH v10 5/6] dt-bindings: backlight: Add led-backlight binding Message-ID: <20191121182228.GO43123@atomide.com> References: <20191009085127.22843-1-jjhiblot@ti.com> <20191009085127.22843-6-jjhiblot@ti.com> <20191009193523.GA7094@bogus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191009193523.GA7094@bogus> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi, * Rob Herring [700101 00:00]: > On Wed, Oct 09, 2019 at 10:51:26AM +0200, Jean-Jacques Hiblot wrote: > > Add DT binding for led-backlight. ... > > new file mode 100644 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/leds/backlight/led-backlight.yaml ... > > + default-brightness: > > + $ref: /schemas/types.yaml#/definitions/uint32 > > + description: Default brightness level on boot. > > It's not clear that this is an index when 'brightness-levels' is present > and absolute level when not. I wonder if we've been consistent on that? Yeah.. And should we use "default-brightness-level" here like we do in the kernel now? Sorry if I've missed some discussion on this before.. > > + brightness-levels = <0 4 8 16 32 64 128 255>; What we're using for droid4 with an earlier version of this patch set for the brightness-levels is generated backwards with: $ for i in 0 1 2 3 4 5 6 7; do echo "255 - ${i} * (256 / 8)" | bc; done This produces the following range that seem to behave nicely: brightness-levels = <31 63 95 127 159 191 223 255>; Of course depends on the backing hardware, this is with leds_lm3532 on droid4. But I think also the current example in the binding might be from Pavel also for droid4? If so, you might want to update the range :) Regards, Tony