From owner-freebsd-arm@FreeBSD.ORG Tue Oct 7 13:16:49 2014 Return-Path: Delivered-To: freebsd-arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id BEBA0D2F for ; Tue, 7 Oct 2014 13:16:49 +0000 (UTC) Received: from mho-01-ewr.mailhop.org (mho-03-ewr.mailhop.org [204.13.248.66]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 8F8C5D83 for ; Tue, 7 Oct 2014 13:16:49 +0000 (UTC) Received: from [73.34.117.227] (helo=ilsoft.org) by mho-01-ewr.mailhop.org with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.72) (envelope-from ) id 1XbUdD-0005ph-KC; Tue, 07 Oct 2014 13:16:47 +0000 Received: from [172.22.42.240] (revolution.hippie.lan [172.22.42.240]) by ilsoft.org (8.14.9/8.14.9) with ESMTP id s97DGkPf030412; Tue, 7 Oct 2014 07:16:46 -0600 (MDT) (envelope-from ian@FreeBSD.org) X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 73.34.117.227 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX19vqqERSvqgumzZrzA64fr0 X-Authentication-Warning: paranoia.hippie.lan: Host revolution.hippie.lan [172.22.42.240] claimed to be [172.22.42.240] Subject: Re: Digi CCWMX53 From: Ian Lepore To: Russell Haley In-Reply-To: References: <27A69721-D93D-4D4C-883A-718CFFF52B21@bsdimp.com> <1412613830.12052.121.camel@revolution.hippie.lan> Content-Type: text/plain; charset="us-ascii" Date: Tue, 07 Oct 2014 07:16:45 -0600 Message-ID: <1412687805.12052.199.camel@revolution.hippie.lan> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 FreeBSD GNOME Team Port Content-Transfer-Encoding: 7bit Cc: freebsd-arm@freebsd.org X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 07 Oct 2014 13:16:49 -0000 On Mon, 2014-10-06 at 21:41 -0700, Russell Haley wrote: > Hey, > > Okay, I lied about waiting till the weekend. I am looking at the atmel > files. Should I be replacing the at91 moniker with imx (processor > class) or mx53 (implementation)? > > Thanks, > > Russ With a quick glance at the manuals, it appears imx51 and imx53 have the same nand controller hardware, but imx6 is completely different, so 'imx5' would be the right prefix for file and function/data names. That said, I want to point out that there's a huge difference between the simplistic memory controller for accessing nand in the at91 hardware and the much more complex nand hardware in the imx5 series. I don't think you're going to get far by trying to copy the at91 driver. In fact, I think you're going to find it impossible to make the imx5 BCH hardware work with the upper layers of the nand software in freebsd without some serious redesign of the upper layers (and then of course the associated rewriting of existing low-level nfc drivers). It's not that I want to discourage you from trying, I just want to be realistic here. What you're embarking on isn't a couple days of converting an existing driver -- in my estimation, you're looking at weeks of work. I don't mean 3 calendar weeks of a couple hours each evening hobbyist work, I'm talking hundreds of hours of development time. The harsh reality is that freebsd doesn't have adequate nand flash support for modern hardware. We don't even have the framework of a design that can accomodate things like hardware offload of ECC. -- Ian