From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Mallon Date: Mon, 20 Jun 2011 00:46:08 +0000 Subject: Re: [PATCH 00/10] Enhance /dev/mem to allow read/write of arbitrary Message-Id: <4DFE9850.7030400@gmail.com> List-Id: References: <201106171038.25988.ptesarik@suse.cz> <20110617093032.GA19235@elte.hu> <4DFE7FF9.9070406@gmail.com> <20110620004252.GE19693@parisc-linux.org> In-Reply-To: <20110620004252.GE19693@parisc-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On 20/06/11 10:42, Matthew Wilcox wrote: > On Mon, Jun 20, 2011 at 09:02:17AM +1000, Ryan Mallon wrote: >> There are drivers where this makes sense. For example an FPGA device >> with a proprietary register layout on the memory bus can be done this >> way. The FPGA can simply be mapped in user-space via /dev/mem and >> handled there. If the device requires no access other than memory bus >> reads and writes then writing a custom char device driver just to get an >> mmap function seems a bit overkill. > Calling a 30 line device driver "overkill" might in itself be overkill? > I mean overkill in the sense of having to write the driver at all. Why write a 30 line driver just to re-implement some functionality of /dev/mem? ~Ryan