From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759364Ab1IIQOX (ORCPT ); Fri, 9 Sep 2011 12:14:23 -0400 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:42662 "EHLO opensource2.wolfsonmicro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1759349Ab1IIQOW (ORCPT ); Fri, 9 Sep 2011 12:14:22 -0400 Date: Fri, 9 Sep 2011 09:14:19 -0700 From: Mark Brown To: Jonathan Cameron Cc: linux-kernel@vger.kernel.org, Michael.Hennerich@analog.com, linux-iio@vger.kernel.org Subject: Re: [PATCH 1/2] regmap: Support half writes and padding between register and value. Message-ID: <20110909161418.GB3515@opensource.wolfsonmicro.com> References: <1315490964-25718-1-git-send-email-jic23@cam.ac.uk> <1315490964-25718-2-git-send-email-jic23@cam.ac.uk> <20110908162715.GB3098@opensource.wolfsonmicro.com> <4E69E019.6060601@cam.ac.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4E69E019.6060601@cam.ac.uk> X-Cookie: If you can read this, you're too close. User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 09, 2011 at 10:44:57AM +0100, Jonathan Cameron wrote: > On 09/08/11 17:27, Mark Brown wrote: > > Please do a patch adding padding separately - that does seem like a > > useful thing to have in general, with the option of having it both > > before and after the register. > Happy to do it separately, but not sure the padding before the register > address is a real use case. You pad after to give the device time to > respond, before doesn't make much sense to me on a register based device... > I'll change the naming to make it explicit that it is after the register though > so as to leave room for this to be added in future. Some devices apparently use an entire byte or word with a magic flag in it to distinguish reads and writes. These end up looking like 16 bit registers with only the lower 8 bits actually used in the current code.