From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from de01egw02.freescale.net (de01egw02.freescale.net [192.88.165.103]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "de01egw02.freescale.net", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 3B83BDDD0D for ; Thu, 12 Jul 2007 01:23:59 +1000 (EST) Message-ID: <4694F608.2090503@freescale.com> Date: Wed, 11 Jul 2007 10:23:52 -0500 From: Scott Wood MIME-Version: 1.0 To: Zhang Wei-r63237 Subject: Re: [PATCH 1/4] Add DMA sector to Documentation/powerpc/booting-without-of.txt file. References: <46B96294322F7D458F9648B60E15112C6F3D1E@zch01exm26.fsl.freescale.net> In-Reply-To: <46B96294322F7D458F9648B60E15112C6F3D1E@zch01exm26.fsl.freescale.net> Content-Type: text/plain; charset=us-ascii; format=flowed Cc: linuxppc-dev@ozlabs.org, paulus@samba.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Zhang Wei-r63237 wrote: >>Or don't call it anything. The ability to do extended chain mode is >>implicit in being compatible with fsl,mpc8548-dma. > > > The basic mode could be used for mpc83xx silicons. Yes, and the 83xx device trees will list the compatible as fsl,mpc8349-dma, not fsl,mpc8548-dma. This will tell the driver whether extended chain mode can be used (though I don't really see the benefit to using it even if it is there). >>I'd rather just treat the different DMA channels as >>independent devices, >>rather than children of a dma "bus", and change the compatible name if >>they're not general purpose. There's only one register that's shared >>among the channels, and it's a superfluous status summary register. >> > > > Your and my ideas are both sides of a coin. :-) I think there's a substantive difference between them. Making each channel an independent device makes it easier for other drivers to use them. -Scott