From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from yow.seanm.ca (toronto-hs-216-138-233-67.s-ip.magma.ca [216.138.233.67]) by ozlabs.org (Postfix) with SMTP id D497DB7179 for ; Fri, 3 Sep 2010 07:24:36 +1000 (EST) Date: Thu, 2 Sep 2010 17:24:34 -0400 From: Sean MacLennan To: linuxppc-dev@lists.ozlabs.org, "Ira W. Snyder" Subject: Re: Where to put board-specific drivers Message-ID: <20100902172434.401195b2@lappy.seanm.ca> In-Reply-To: <20100902211221.GD24861@ovro.caltech.edu> References: <20100902200434.GC24861@ovro.caltech.edu> <320E0907-436B-42B8-9E85-EABF481FE04C@kernel.crashing.org> <20100902211221.GD24861@ovro.caltech.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2 Sep 2010 14:12:22 -0700 "Ira W. Snyder" wrote: > To give you three example drivers: > 1) Data processing FPGA access driver > > This driver provides a simple character device to userspace which > exposes one function: mmap. With it, you can mmap the entire data > processing FPGA memory window into your process. With this, I provide > non-realtime FPGA control to userspace applications. > > 2) Data processing FPGA capture driver > > This driver provides a simple character device to userspace which > supports one function: read. Internally, it maintains a list of > buffers which hold capture data. When the FPGA's are processing data, > they dump data at 64Hz (every 15.625ms). If the data is not copied > off the chips before the next dump, data is lost. > > DMA is required to move the data volume off the FPGAs fast enough to > keep timing. Therefore this really does need to be in-kernel. Could these drivers be merged? Cheers, Sean