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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C4657ECAAA1 for ; Fri, 9 Sep 2022 15:49:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8271410EC99; Fri, 9 Sep 2022 15:49:38 +0000 (UTC) Received: from smtp5-g21.free.fr (smtp5-g21.free.fr [212.27.42.5]) by gabe.freedesktop.org (Postfix) with ESMTPS id B251D10EC99; Fri, 9 Sep 2022 15:49:34 +0000 (UTC) Received: from 82-65-29-218.subs.proxad.net (unknown [IPv6:2a01:e0a:5ef:1450:250:fcff:fe42:7bed]) by smtp5-g21.free.fr (Postfix) with ESMTP id 0279C5FFD8; Fri, 9 Sep 2022 17:49:26 +0200 (CEST) Received: from berkelium.ap2c.org (localhost [127.0.0.1]) by 82-65-29-218.subs.proxad.net (Postfix) with ESMTP id 94269A527; Fri, 9 Sep 2022 17:49:26 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ap2c.com; s=ap2cCom; t=1662738566; bh=KAUFs8Gddcy6mYnYueQePctsnpjY/cWYwMOTf14lGE0=; h=Date:From:Subject:To:Cc:In-Reply-To:References; b=K+185GNFdnN324begdB4IiWbweBPfej2xuzvN336Wb5nkV61eUf3qdaqHUyNRsN3o ax2eaJNZkM1axPcFuxge0+fTTb/EZndSPSHppeYn6WSoMFQAS7zwytmSyeedRuGrq0 roOLfIanXnSaU8/7Wx1EM6306Cqo0m4eR2ok6qPo= X-Virus-Scanned: amavisd-new at ap2c.org Received: from 82-65-29-218.subs.proxad.net ([127.0.0.1]) by berkelium.ap2c.org (berkelium.ap2c.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6iVLbpusZ5py; Fri, 9 Sep 2022 17:49:25 +0200 (CEST) Received: from drive.ap2c.org (imap.ap2c.org [10.8.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by 82-65-29-218.subs.proxad.net (Postfix) with ESMTPSA; Fri, 9 Sep 2022 17:49:25 +0200 (CEST) MIME-Version: 1.0 Date: Fri, 09 Sep 2022 15:49:24 +0000 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Mailer: RainLoop/1.16.0 From: "=?utf-8?B?QXVyw6lsaWVu?=" Message-ID: <115b5a5ebddcd268ee5f7688400448a2@ap2c.com> To: "Jani Nikula" , "Rodrigo Vivi" , "Hans de Goede" , "Lyude" , dri-devel@lists.freedesktop.org In-Reply-To: <878rms7emr.fsf@intel.com> References: <878rms7emr.fsf@intel.com> <183219aab00.2890.be34037ad6564a4fe81285fd91a8f407@ap2c.com> Subject: Re: [Intel-gfx] Developing a new backlight driver for specific OLED screen X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Hi,=20 >=20+ dri-devel mailing list that looks more appropriated. > + Hans and Lyude who were recently working to standardize some of the > backlight stuff. Thank you for these contacts. I'll try there if I need. > I don't believe you want to use the i915 API, but move the common funct= ions > to the drm subsystem itself and then reuse as a drm device. If there is enough generic code I'll do everything with the DRM API. Unfo= rtunately I can't spend too much time in order to generalize the i915 com= mon functions. > Aur=C3=A9lien, are you aware of drivers/gpu/drm/display/drm_dp_helper.c= and > all the functions around struct dp_aux_backlight and struct > drm_edp_backlight_info? Not yet. Since I'm not familiar with GPU/display drivers I didn't know wh= at could be a good starting point.=20 Indeed=20I already checked the intel_dp_aux_backlight.c code. That's why = I told about using the "i915 API code" at first. But since this display i= s independent from the GPU i didn't want to link both code.=20 Then=20that's a really good point if there is already an independant API.= I'll have a look this evening. > Does the display use some proprietary, non-VESA DPCD registers? There's > already some of that in i915 for Intel proprietary interfaces. For sure. It's an OLED display. Thus there is no backlight. It uses speci= fic registers to control the brightness of the screen. Unfortunately I guess the mechanism is not shared with many OLED displays= ... Thank you for your help. Aur=C3=A9lien