From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id E7D4CDDE30 for ; Wed, 1 Aug 2007 08:48:08 +1000 (EST) In-Reply-To: <46A798D8.7020906@freescale.com> References: <20070725165318.5331.23795.stgit@localhost.localdomain> <20070725165326.5331.19920.stgit@localhost.localdomain> <46A78322.3080607@ru.mvista.com> <46A78E3F.1030904@ru.mvista.com> <20070725180145.GA29689@ld0162-tx32.am.freescale.net> <46A7941F.2050300@ru.mvista.com> <46A798D8.7020906@freescale.com> Mime-Version: 1.0 (Apple Message framework v623) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <14924a51c8a1664a21a85f450d503e82@kernel.crashing.org> From: Segher Boessenkool Subject: Re: [PATCH 2/2] [POWERPC] MPC8349E-mITX: use platform IDE driver for CF interface Date: Wed, 1 Aug 2007 00:47:57 +0200 To: Scott Wood Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , >> I never suggested that -- what I did suggest was make of_serial.c >> recognize certain chip types and register them with 8250 driver. > > What would be the advantage of maintaining a list of chips whose only > difference is register spacing, rather than just using reg-shift and > being done with it? reg-shift alone isn't enough to know how to access the device registers. In the case of UARTs, they typically are internal to some SoC, so the device driver can just look up what SoC it is and will then know what to do. For IDE though, as far as I understand it typically is board-specific, done by some glue logic off of some GPIOs or on an FPGA; I think detection is best handled by platform code in this case, an "mmio-ide" shim driver would be helpful of course. Segher