Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756556Ab3IPMzc (ORCPT ); Mon, 16 Sep 2013 08:55:32 -0400 Received: from mail-qa0-f52.google.com ([209.85.216.52]:54849 "EHLO mail-qa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754518Ab3IPMza convert rfc822-to-8bit (ORCPT ); Mon, 16 Sep 2013 08:55:30 -0400 MIME-Version: 1.0 In-Reply-To: <20130915124325.B1DF2C42C5C@trevor.secretlab.ca> References: <1378863781-4235-1-git-send-email-emilio@elopez.com.ar> <1379032225-6425-1-git-send-email-emilio@elopez.com.ar> <52326ADC.8040703@elopez.com.ar> <20130915124325.B1DF2C42C5C@trevor.secretlab.ca> Date: Mon, 16 Sep 2013 07:55:29 -0500 Message-ID: Subject: Re: [PATCH] memory: add a basic OF-based memory driver From: Rob Herring To: Grant Likely Cc: Olof Johansson , =?ISO-8859-1?Q?Emilio_L=F3pez?= , Mike Turquette , Maxime Ripard , Rob Herring , Greg Kroah-Hartman , "devicetree@vger.kernel.org" , =?ISO-8859-1?Q?David_Lanzend=F6rfer?= , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2013 Lines: 42 On Sun, Sep 15, 2013 at 7:43 AM, Grant Likely wrote: > On Fri, 13 Sep 2013 08:49:06 -0700, Olof Johansson wrote: >> On Fri, Sep 13, 2013 at 7:00 AM, Rob Herring wrote: >> > On Thu, Sep 12, 2013 at 8:31 PM, Emilio L?pez wrote: [snip] >> > Better, but this is still wrong. DT describes the hardware. There is >> > no such h/w as a simple-memory-controller. The fact that you have a >> > simple-memory-ctrlr kernel driver is a kernel >> > feature/artifact/limitation. Describe the h/w with a meaningful >> > compatible string and put that string in the simple memory controller >> > driver match table. If someday we have a real driver for said memory >> > controller, then it is only a kernel change to use a different driver. >> >> >> We discussed this over IRC last night -- I still think it makes more >> sense to make the clock driver for sunxi aware of this and just add a >> reference to the clock at init time. >> >> This is never going to differ from board to board (today the clock >> name is the same on all sunxi platforms -- pll5_ddr. And the need will >> likewise be there for all platforms at this time. >> >> If and when it changes in the future, we can reevaluate. But this >> doesn't have to be driven by device tree at this time, it seems to >> just make things overly complicated and contrived. > > I agree. Creating a new platform driver + device tree binding just to > claim a clock that must not be disables does not look like the right > approach to me either. Maybe a driver is overkill, but fully describing the h/w would be a good thing. Only defining the h/w that Linux currently uses is not a good practice (although admittedly hard to avoid). Rob -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/