From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758112Ab2DMJIu (ORCPT ); Fri, 13 Apr 2012 05:08:50 -0400 Received: from na3sys009aog101.obsmtp.com ([74.125.149.67]:54297 "EHLO na3sys009aog101.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757864Ab2DMJIs (ORCPT ); Fri, 13 Apr 2012 05:08:48 -0400 Date: Fri, 13 Apr 2012 12:07:52 +0300 From: Felipe Balbi To: "Cousson, Benoit" Cc: Paul Walmsley , "Balbi, Felipe" , "Mohammed, Afzal" , Greg KH , "Shilimkar, Santosh" , "V, Aneesh" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-omap@vger.kernel.org" , "mgreer@animalcreek.com" , "msalter@redhat.com" Subject: Re: [PATCH v4 0/7] Add TI EMIF SDRAM controller driver Message-ID: <20120413090750.GM4343@arwen.pp.htv.fi> Reply-To: balbi@ti.com References: <1331934707-29487-1-git-send-email-aneesh@ti.com> <20120412030044.GA26236@kroah.com> <4F867A95.9030104@ti.com> <20120412131045.GB31384@kroah.com> <4F87240F.6060902@ti.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="x38akuY2VS0PywU3" Content-Disposition: inline In-Reply-To: <4F87240F.6060902@ti.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --x38akuY2VS0PywU3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Apr 12, 2012 at 08:50:55PM +0200, Cousson, Benoit wrote: > + Felipe, >=20 > Hi Paul, >=20 > On 4/12/2012 7:00 PM, Paul Walmsley wrote: > >Hi > > > >On Thu, 12 Apr 2012, Mohammed, Afzal wrote: > > > >>On Thu, Apr 12, 2012 at 18:40:45, Greg KH wrote: > >>>On Thu, Apr 12, 2012 at 12:17:49PM +0530, Santosh Shilimkar wrote: > >>>>I was hoping that we will have some thing like drivers/memory/* > >>>>but since it doesn't exist, we used drivers/misc. > >>> > >>>Why not create it? I have no objection to that, it makes it more > >>>obvious as to what this really is. > >> > >>There is another memory controller used in a few TI SoCs, > >>namely GPMC [1], do you prefer having it too there. > >> > >>As of now it is not a driver, platform code handles GPMC, a patch > >>series for converting it into a driver (but still residing in > >>platform folder) was sent a few days back [2,3]. > > > >Probably the GPMC driver should go into a slightly different place than > >SDRC/EMIF. > > > >GPMC is actually a general-purpose parallel bus driver. It's used to > >interface Ethernet controllers, UARTs, FPGAs, NAND/NOR flash, SRAM, etc. > >It cannot be used to control DRAM, at least not without a separate DRAM > >controller chip. > > > >SDRC/EMIF are both DRAM controllers. That's all they do. They can't be > >used to control anything else. They implement DRAM refresh, etc. >=20 > The LPDDR2 spec does consider as well NVM (Non Volatile Memory), so I > think we should stick to driver/memory for EMIF. >=20 > >So perhaps something like drivers/memory/dram/ for the SDRAM controllers, > >and maybe drivers/memory/ for the GPMC? >=20 > In fact Felipe was considering something else for that kind of > general purpose bus driver like GMPC, C2C and LLI... >=20 > ... But I do not remember the name :-) the name matters very little :-) But the idea was to avoid writing yet another bus driver and just use the platform_bus instead. We would do all the channel/port setup before hand and far-end device driver wouldn't have to know if it's integrated into the SoC or plugged though LLI/C2C/GPMC. =46rom the driver's perspective it would look the same. --=20 balbi --x38akuY2VS0PywU3 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJPh+zmAAoJEIaOsuA1yqREOy8P/2j0xBGDA5Maaws8NVYT0cOR vmyW249XqyNhYzOxi/l9wUAHtM5vxSwBG5J856DjWmiZHPHCdhD24fSM7rL7kpA7 CG//baD2JJvDpfL/O7GGjlx9GxmohsmoDmyOGTkhhWrfkTHJ5vYJjpsUsTp1cdLP M1zzfBkJPbquY2itdF6ezKVJL1jxHDfjQwMghRHo5d86wyjvEnEicvwfojZU4QcS n5MCND/6Xu6jFF4atxsZSvkv8xadGm+ih3ToCs1WRBI7xn8lGQ0pm0QTO3bQRfKU ZbAF058Gcd5DfWtAzdBWwmp3IWNjfKuWk4YiVrzdoaLscZAnftGSK9HPdsdyy9kN U55/JIKOttOXazYqmxO36KHF1gLKmAzTwD/B2phDbrJXIK2ZdGgL2rMEHUtvBfDR iMTv2dxTGjtdlMGFwF461vd5FVUekUGFAI9vxP2TZMC5CCqQnktoUm2YKseXbxdt p5uiYDRP+KmpG7UqGtbIDGDLX6zocvpLi855zXlHn6NGFYQMCZGxYaiUuNsx/ljd wgQeiK/E/DYy9uOqwgFmr91Rne1d1aTJe4wwAFqCyeR8UHaWAA7ywGag4nM4fNdV ibJ7GE6mj4ojQY4nP4JUF8EwnpUm83Rc3kizTWxCbfyd02rhOJ/d7Y+06oSHBRoI 0Et8Pbb+prFyqtQq8nmT =inf9 -----END PGP SIGNATURE----- --x38akuY2VS0PywU3--