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 7CAD3C3526D for ; Wed, 26 Jan 2022 14:09:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241840AbiAZOJp (ORCPT ); Wed, 26 Jan 2022 09:09:45 -0500 Received: from mga07.intel.com ([134.134.136.100]:46235 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233834AbiAZOJn (ORCPT ); Wed, 26 Jan 2022 09:09:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643206183; x=1674742183; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=+bpZlvDIlAqOTrKi8qQY7oqDaN358NSulwLrW+ejnTU=; b=cN4OVl5BU86577/2bbBE5xvGU4lRlgfc+4wCdkAN2CNpoYbqFlIzCFxe AC8KzvBty3GAbRdtEXkXHYTQBV5rgY6m0pCpCM7fufwrOL1r5un7hhgRW rHCqNwolv25gxPTN67jWSWQaMF4auoZYwEI4F4uID58A0pH9oIDXgY+H5 36vr5gmADE+X5oBikmxpzQAECb7oEKkblvn2sXH5z3bjP4Klq61oW8DTL 3/vayOwfFG4Ocz94gTxjixZqx56qopkied73kpVQwG2XlLcFphZ4EG0q6 AZpSr5FYGTiRee/dkYm0Df7WeRTZEIv0W6d46qkHuLSsTTZYDBjYSltG/ A==; X-IronPort-AV: E=McAfee;i="6200,9189,10238"; a="309869018" X-IronPort-AV: E=Sophos;i="5.88,318,1635231600"; d="scan'208";a="309869018" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2022 06:09:42 -0800 X-IronPort-AV: E=Sophos;i="5.88,318,1635231600"; d="scan'208";a="581113085" Received: from smile.fi.intel.com ([10.237.72.61]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2022 06:09:39 -0800 Received: from andy by smile.fi.intel.com with local (Exim 4.95) (envelope-from ) id 1nCiyO-00EcSP-TH; Wed, 26 Jan 2022 16:08:32 +0200 Date: Wed, 26 Jan 2022 16:08:32 +0200 From: Andy Shevchenko To: Javier Martinez Canillas Cc: Greg Kroah-Hartman , Andy Shevchenko , linux-fbdev@vger.kernel.org, Michael Hennerich , Helge Deller , linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Phillip Potter , Carlis , Lee Jones , Heiner Kallweit Subject: Re: [PATCH v1 1/4] fbtft: Unorphan the driver Message-ID: References: <20220125202118.63362-1-andriy.shevchenko@linux.intel.com> <20220125202118.63362-2-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 26, 2022 at 02:46:08PM +0100, Javier Martinez Canillas wrote: > On 1/26/22 14:12, Andy Shevchenko wrote: > > On Wed, Jan 26, 2022 at 12:26:36PM +0100, Greg Kroah-Hartman wrote: > >> On Wed, Jan 26, 2022 at 12:17:08PM +0100, Helge Deller wrote: > >>> On 1/26/22 11:31, Daniel Vetter wrote: > > > > ... > > > >>> You are describing a transitioning over to DRM - which is Ok. > >>> But on that way there is no need to ignore, deny or even kill usage scenarios > >>> which are different compared to your usage scenarios (e.g. embedded devices, > >>> old platforms, slow devices, slow busses, no 3D hardware features, > >>> low-color devices, ...). > >> > >> All of those should be handled by the drm layer, as Daniel keeps > >> pointing out. If not, then the tinydrm layer needs to be enhanced to do > >> so. > >> > >> Anyone have a pointer to hardware I can buy that is one of these fbtft > >> drivers that I could do a port to drm to see just how much work is > >> really needed here? > > > > I have bought myself (for other purposes, I mean not to convert the driver(s)) > > SSD1306 based display (SPI), SSD1331 (SPI), HX88347d (parallel). > > > > I've just bought a SSD1306 (I2C) based one and will attempt to write a DRM > driver using drivers/staging/fbtft/fb_ssd1306.c as a reference. You should take ssd1307fb.c instead. And basically create a MIPI based driver for I2C. Then we won't go same road again for other similar devices. > I didn't find one with a SPI interface but we can later add a transport for > that if I succeed. -- With Best Regards, Andy Shevchenko