From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ppsw-50.csi.cam.ac.uk ([131.111.8.150]:34974 "EHLO ppsw-50.csi.cam.ac.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753785Ab1G1Hzo (ORCPT ); Thu, 28 Jul 2011 03:55:44 -0400 Message-ID: <4E3117DD.9060904@cam.ac.uk> Date: Thu, 28 Jul 2011 09:03:41 +0100 From: Jonathan Cameron MIME-Version: 1.0 To: michael.hennerich@analog.com CC: "linux-iio@vger.kernel.org" , "device-drivers-devel@blackfin.uclinux.org" Subject: Re: [PATCH 0/2] blue part 6: IIO abi rework References: <1311600234-16128-1-git-send-email-jic23@cam.ac.uk> <544AC56F16B56944AEC3BD4E3D59177143001196A7@LIMKCMBX1.ad.analog.com> <4E2E863C.2010706@cam.ac.uk> <4E2E9C77.9050506@analog.com> <4E2E9FC5.4030809@cam.ac.uk> <4E3023A3.80604@analog.com> In-Reply-To: <4E3023A3.80604@analog.com> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 07/27/11 15:41, Michael Hennerich wrote: > On 07/26/2011 01:06 PM, Jonathan Cameron wrote: >> On 07/26/11 11:52, Michael Hennerich wrote: >>> On 07/26/2011 11:17 AM, Jonathan Cameron wrote: >>>> On 07/26/11 10:01, Hennerich, Michael wrote: >>>>> Jonathan Cameron wrote on 2011-07-25: >>>>>> Michael pointed out the issues that not having an explicit direction >>>>>> for channels was causing and the inconsistency of the inX and outX >>>>>> channel naming we got from hmwon. >>>>>> >>>>>> They are stuck with it, but we aren't, so lets fix this now. >>>>>> >>>>>> Interesting question is whether we reset the base units to be volts >>>>>> whilst we are at it? (for voltage channels obviously!) >>>>> What do you mean exactly volts versus milli volts? >>>> Make the in_voltage_scale correspond to conversion to volts instead of >>>> millivolts as now (I think). Err. Looking at it that isn't actually documented... >>>> oops. I wonder which drivers actually do that and which don't. >>> The ones I wrote provide the scale for millivolts. >>> With the recent introduction of IIO_VAL_INT_PLUS_NANO we got >>> the scale accurate enough for the precession 24-bit converters. >>> If we move to the SI base unit volt, we lose this accuracy again. >> Yup, that's the principal counter argument to the change. > If we decide to leave the milli scale for volts... > Do we also want to stay with milli degrees Celsius, etc.? If we do it for one, probably best to do it for them all.. > > One other thing we should also address is the byte-ordering/endianess of > the scan elements stored in the ring buffers. > > Right now the scan_element type details signs, bits, storage bits and shifts. > However it lacks to tell the endianess within the storage bits. Good point. I'd completely forgotten about that. > > How about le:s16/32>>0 or be:s16/32>>0 for example? Yup, that works for me. In cases where it doesn't matter they driver can pick one at random. Jonathan