From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757632Ab3LFJOS (ORCPT ); Fri, 6 Dec 2013 04:14:18 -0500 Received: from 7of9.schinagl.nl ([88.159.158.68]:38795 "EHLO 7of9.schinagl.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757395Ab3LFJOI (ORCPT ); Fri, 6 Dec 2013 04:14:08 -0500 Message-ID: <52A19502.1090409@schinagl.nl> Date: Fri, 06 Dec 2013 10:12:34 +0100 From: Oliver Schinagl User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 MIME-Version: 1.0 To: Thomas Petazzoni CC: Tejun Heo , Olliver Schinagl , grant.likely@linaro.org, "rob.herring@calxeda.com" , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, dev@linux-sunxi.org, maxime.ripard@free-electrons.com, ijc@hellion.org.uk, hdegoede@redhat.com, Richard Zhu , Shawn Guo Subject: Re: [PATCH 2/3] ARM: sunxi: Add an ahci-platform compatible AHCI driver for the Allwinner SUNXi series of SoCs References: <1386159055-10264-1-git-send-email-oliver@schinagl.nl> <1386159055-10264-3-git-send-email-oliver@schinagl.nl> <20131204123708.GD3158@htj.dyndns.org> <529F2677.3070208@schinagl.nl> <20131204131402.GG3158@htj.dyndns.org> <529F2B41.8090009@schinagl.nl> <20131204132312.GH3158@htj.dyndns.org> <20131206100117.59609a8a@skate> In-Reply-To: <20131206100117.59609a8a@skate> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06-12-13 10:01, Thomas Petazzoni wrote: > Dear Tejun Heo, > > On Wed, 4 Dec 2013 08:23:12 -0500, Tejun Heo wrote: > >>> But again, point me (for dummies ;) in the right direction and I'll >>> work on it with some help. >> Richard and Shawn recently worked on ahci_imx. Can you guys please >> talk with each other and figure out what can be done to share as much >> as possible among these new platform-specific drivers? I'd really >> like to see the common things factored out as much as possible with >> only the actual hardware differences described for each device. > Also, please Cc me on such discussions. I have a pending AHCI platform > driver for another ARM SoC family. It is very similar to ahci_platform, > but needs to do a few more things that are SoC specific (map an > additional register area, and do some SoC-specific stuff with them). > > For the moment, we're left with two approaches: > > * Do what Oliver did, where the ahci_ driver will do its own > SoC-specific stuff, and then will register an additional > platform_device to trigger the ->probe() of the generic > ahci_platform driver. I must say I don't really like this solution, > since it involves having two platform_device registered for the same > piece of hardware (one platform_device to trigger the ->probe of > ahci_, and another one to trigger the ->probe of ahci_platform). > > * Duplicate in ahci_ the (relatively small) amount of code that > is present in ahci_platform. > > From my point of view, ahci_platform should be turned into a small > "library", that provides an API for ahci_ drivers to 1/ do their > own custom stuff and 2/ do the common ahci_platform stuff. > > This way we avoid the registration of two platform_device for the same > piece of hardware, and we avoid the duplication of code. > > Want me to propose a RFC for this idea? I've started to do what sdhci does with their pltfrm driver, assuming that's the right approach. Since i'm only dabbling and not always 100% sure what should or shouldn't be done, it may take a little while, but looks promising from my end ;) So is the sdhci-pltfrm approach the correct one? We still have ahci_* drivers, but ahci_platform.c won't be a driver in the sense that it is now anymore. Oliver > > Best regards, > > Thomas