From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932804Ab2AMUMP (ORCPT ); Fri, 13 Jan 2012 15:12:15 -0500 Received: from na3sys009aog126.obsmtp.com ([74.125.149.155]:40283 "EHLO na3sys009aog126.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932781Ab2AMUMO (ORCPT ); Fri, 13 Jan 2012 15:12:14 -0500 Date: Fri, 13 Jan 2012 22:12:07 +0200 From: Felipe Balbi To: Greg KH Cc: "Gupta, Ajay Kumar" , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: RFC: usb: musb: Adding CPPI4.1 DMA driver under drivers/dma Message-ID: <20120113201205.GK3133@legolas.emea.dhcp.ti.com> Reply-To: balbi@ti.com References: <201201120753.00667.oneukum@suse.de> <20120112215014.GC5735@xanatos> <20120112215459.GA1161@kroah.com> <20120112222947.GD5735@xanatos> <20120112223513.GA2925@kroah.com> <20120113061144.GA30569@suse.cz> <47CEF8C4B26E8C44B22B028A650E0EA9317A6B8B@DBDE01.ent.ti.com> <20120113180932.GB29700@kroah.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="o+ZCuNqY+dEAKBWl" Content-Disposition: inline In-Reply-To: <20120113180932.GB29700@kroah.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 --o+ZCuNqY+dEAKBWl Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jan 13, 2012 at 10:09:32AM -0800, Greg KH wrote: > On Fri, Jan 13, 2012 at 10:40:50AM +0000, Gupta, Ajay Kumar wrote: > > Hi, > >=20 > > CPPI4.1 (Communication Port Programming Interface) is a TI specific DMA > > controller used in multiple TI platform such as AM33x, DA8x, AM35x, TI8= 1x. > > The DMA engine is mainly used by musb controller on above platform. > >=20 > > Earlier version of the driver was submitted by Sergei Shtylyov at [1] b= ut > > was not merged due to disagreement on the location of driver in kernel. > > Refer the discussions at [1] for more details. > >=20 > > [1] http://marc.info/?l=3Dlinux-usb&m=3D125087318308323 > >=20 > > The new implementation of the CPPI4.1 DMA slave driver will be in the > > drivers/dma folder, complying to dmaengine framework. > > It would involve changes in existing musb driver also for which current > > plan is to maintain the compatibility of non-CPPI4.1 DMA in musb driver= =2E=20 > >=20 > > The task is planned to be spitted into below subtasks. > >=20 > > (1) Post RFC on the API details, changes envisaged in musb driver and o= ther > > challenges > >=20 > > (2) Implement and post RFC for the CPPI4.1 DMA driver and changes neede= d in > > musb driver. > >=20 > > Let me know if you have any thoughts/comments on this. >=20 > First off, don't highjack threads (you responded to a linux-usb thread > here, get a better email client please.) >=20 > Second, that sounds fine, please post patches. I'm with Greg here, please post patches. What I suggest is: - first create a dma-engine.c file on drivers/usb/musb which will simply translate dmaengine into the MUSB-specific API. this will allow us to slowly convert other platforms without breaking the legacy stuff. - Then move CPPI to drivers/dma - Test it all out ;-) --=20 balbi --o+ZCuNqY+dEAKBWl Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAEBAgAGBQJPEJAVAAoJEIaOsuA1yqREaT8P/iWtoGRmWUYAgePvDAWNihxw EvR5TvjtHJZkxH9czB+wJELYDesZmvS6neM9rb1DROL2Hjaa4Ghg/vk1oB03kylZ JtBW2w28/p7jRgcUuQglcvyilI4ura5dNtuxWPn7c/8OO7oGxMMmaA4WcA+gKxGK nCUt6HexyTTQC6NhELwl16jZGe4ZV9wnKgl7C5TypvMVqrgdgkoCUjFOSwjFDN+f K6fCZ1+IxPU+iqd5lEfHUyOU8fiV3W5/SRDRfkYgryyiMUcYyg6oXMk1mP/7/Ae5 qP8nAwA2h3qMY/wtFFnBNq4s5HDzAsKmM6dpzPPJs0OB9AsNVCAHREVdJnJQwBQp pvEPoRVWN8HxCLAv04gwTlCMu3fb6MUkvm84KcMOo+bEQojLwv730oB8vua+Kn0J 65g+7Gv80hxGZ1+WsXstO/cvQ3oV32SQWbrjKjCL2NOFVxm8vXpoDRs4XAl21iCx AwY3Y1aK+ut/4gG4DcN4eKU3Xv56w2Rl899q7Vg+nwt04tLD3nYRAytxh5ptqSoF dvac8d7P86PaNaiCD1Wz6wvjIS8SZlpysN/0U32UYvWz2h3E1IOxYUsIHQRXKKkf vCEO7bm50spLnWUd+AdXaYDEAIQ8hegdN1lm6a3etBBE8imP2MNzzx/4Kce7ruAC UINkz3afCJmHWJEr4+OT =J/ws -----END PGP SIGNATURE----- --o+ZCuNqY+dEAKBWl--