From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: [PATCH 2/3] ARM: sunxi: Add an ahci-platform compatible AHCI driver for the Allwinner SUNXi series of SoCs Date: Fri, 06 Dec 2013 12:06:00 +0100 Message-ID: <52A1AF98.7020003@redhat.com> 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> <52A19502.1090409@schinagl.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <52A19502.1090409@schinagl.nl> Sender: linux-ide-owner@vger.kernel.org To: Oliver Schinagl , 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, Richard Zhu , Shawn Guo List-Id: devicetree@vger.kernel.org Hi, On 12/06/2013 10:12 AM, Oliver Schinagl wrote: > > 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. Sounds good to me. May I suggest simply adding a new ahci_pltfrm driver for this and leaving the existing ahci_platform alone? Of course in the end we want the old ahci_platform to go away, but it is probably best to introduce the new one in parallel and then port things over 1 by 1 by people who can actually test the port :) Regards, Hans