From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.ebshome.net (gate.ebshome.net [208.106.21.240]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (Client CN "gate.ebshome.net", Issuer "gate.ebshome.net" (not verified)) by ozlabs.org (Postfix) with ESMTP id ECF6167BC4 for ; Sat, 30 Sep 2006 02:42:48 +1000 (EST) Date: Fri, 29 Sep 2006 09:42:45 -0700 From: Eugene Surovegin To: Jean-Baptiste Maneyrol Subject: Re: [PATCH] IBM GPIO driver for PowerPC 4xx is back from the dead Message-ID: <20060929164245.GA17656@gate.ebshome.net> References: <1159515965.5613.4.camel@jb-portable> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1159515965.5613.4.camel@jb-portable> Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Sep 29, 2006 at 09:46:04AM +0200, Jean-Baptiste Maneyrol wrote: > Here is a patch for linux 2.6.18 that makes come back the old ibm gpio > driver from 2.6.10. > > It is mainly useful for compatibility with old linux 2.4 from Montavista > I think, because direct memory access seems the new way to go. In my opinion it should stay dead. And no, direct memory access isn't a way to go - how are you gonna provide synchronization in this case? Think about different processes mucking with GPIO registers. I think such low-level functionality should never be exported to the user-space in the first place. If your user-space needs such access make it explicit through procfs/sysfs (e.g. /proc/sys/dev/my_board/reset_that_device for GPIO pin wired to some chip reset) or just make a specific driver for your hardware. -- Eugene