From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757821Ab0IBWWu (ORCPT ); Thu, 2 Sep 2010 18:22:50 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:42497 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756901Ab0IBWWs (ORCPT ); Thu, 2 Sep 2010 18:22:48 -0400 Date: Thu, 2 Sep 2010 23:41:24 +0100 From: Alan Cox To: Andrew Chew Cc: "linux-kernel@vger.kernel.org" , "linux-iio@vger.kernel.org" , "linux-i2c@vger.kernel.org" , "akpm@linux-foundation.org" , "khali@linux-fr.org" , Laxman Dewangan Subject: Re: [PATCH 1/1] iio: ak8975: Add Ak8975 magnetometer sensor Message-ID: <20100902234124.584b9bf7@lxorguk.ukuu.org.uk> In-Reply-To: <643E69AA4436674C8F39DCC2C05F763816B85AD096@HQMAIL03.nvidia.com> References: <1283463351-15816-1-git-send-email-achew@nvidia.com> <20100902231942.21375cc0@lxorguk.ukuu.org.uk> <643E69AA4436674C8F39DCC2C05F763816B85AD096@HQMAIL03.nvidia.com> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.18.9; x86_64-redhat-linux-gnu) Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwBAMAAAClLOS0AAAAFVBMVEWysKsSBQMIAwIZCwj///8wIhxoRDXH9QHCAAABeUlEQVQ4jaXTvW7DIBAAYCQTzz2hdq+rdg494ZmBeE5KYHZjm/d/hJ6NfzBJpp5kRb5PHJwvMPMk2L9As5Y9AmYRBL+HAyJKeOU5aHRhsAAvORQ+UEgAvgddj/lwAXndw2laEDqA4x6KEBhjYRCg9tBFCOuJFxg2OKegbWjbsRTk8PPhKPD7HcRxB7cqhgBRp9Dcqs+B8v4CQvFdqeot3Kov6hBUn0AJitrzY+sgUuiA8i0r7+B3AfqKcN6t8M6HtqQ+AOoELCikgQSbgabKaJW3kn5lBs47JSGDhhLKDUh1UMipwwinMYPTBuIBjEclSaGZUk9hDlTb5sUTYN2SFFQuPe4Gox1X0FZOufjgBiV1Vls7b+GvK3SU4wfmcGo9rPPQzgIabfj4TYQo15k3bTHX9RIw/kniir5YbtJF4jkFG+dsDK1IgE413zAthU/vR2HVMmFUPIHTvF6jWCpFaGw/A3qWgnbxpSm9MSmY5b3pM1gvNc/gQfwBsGwF0VCtxZgAAAAASUVORK5CYII= Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2 Sep 2010 15:16:20 -0700 Andrew Chew wrote: > > > +static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, show_mode, > > store_mode, 0); > > > +static IIO_DEVICE_ATTR(magn_x_calibscale, S_IRUGO, > > show_calibscale, NULL, 0); > > > +static IIO_DEVICE_ATTR(magn_y_calibscale, S_IRUGO, > > show_calibscale, NULL, 1); > > > +static IIO_DEVICE_ATTR(magn_z_calibscale, S_IRUGO, > > show_calibscale, NULL, 2); > > > +static IIO_DEV_ATTR_MAGN_X(show_raw, AK8975_REG_HXL); > > > +static IIO_DEV_ATTR_MAGN_Y(show_raw, AK8975_REG_HYL); > > > +static IIO_DEV_ATTR_MAGN_Z(show_raw, AK8975_REG_HZL); > > > > This seems odd as an interface as it's raw when the maths to provide > > non-raw (and thus abstract and easy for user space) data is trivial > > enough to do in kernel > > IIO guys want to do normalization maths above the kernel-level magnetometer IIO layer. This interface came before me, so I'm just following current conventions. That will make a generic IIO <-> input bridge very hard to do right. I can see why IIO wants to do that but you need both if so and this also needs discussion.