From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753872AbaCYRBI (ORCPT ); Tue, 25 Mar 2014 13:01:08 -0400 Received: from quartz.orcorp.ca ([184.70.90.242]:41815 "EHLO quartz.orcorp.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752779AbaCYRBG (ORCPT ); Tue, 25 Mar 2014 13:01:06 -0400 Date: Tue, 25 Mar 2014 11:01:02 -0600 From: Jason Gunthorpe To: Lee Jones Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, angus.clark@st.com, kernel@stlinux.com, linux-mtd@lists.infradead.org, pekon@ti.com, computersforpeace@gmail.com, dwmw2@infradead.org, Boris BREZILLON Subject: Re: [RFC 02/47] mtd: nand: add ONFI NAND Timing Mode Specifications Message-ID: <20140325170102.GC30641@obsidianresearch.com> References: <1395735604-26706-1-git-send-email-lee.jones@linaro.org> <1395735604-26706-3-git-send-email-lee.jones@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1395735604-26706-3-git-send-email-lee.jones@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Broken-Reverse-DNS: no host name found for IP address 10.0.0.161 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 25, 2014 at 08:19:19AM +0000, Lee Jones wrote: > This patch adds a new structure, 'nand_timing_spec', to capture the A/C > timing characteristics of NAND devices. Boris BREZILLON has been working on a similar patch for a time now, and I think has an implementation for the sunxi driver. > some of the major NAND manufacturers (e.g. Samsung, Toshiba). Here we > have followed broadly the ONFI timing definitions. Timing specifications that are not precisely defined are useless.. I would stick entirely with the well defined ONFI ones until a need arises.. > + * Note, 'tR' field (maximum page read time) is extracted from the ONFI > + * parameter page during device probe. > + */ > +struct nand_timing_spec nand_onfi_timing_specs[] = { const? > + /* > + * ONFI Timing Mode '0' (supported on all ONFI compliant devices) > + */ > + [0] = { > + .tCLS = 50, > + .tCS = 70, > + .tALS = 50, Use picoseconds, ns is already loosing precision at the higher timing modes. Cheers, Jason