Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751372AbcKGMSS (ORCPT ); Mon, 7 Nov 2016 07:18:18 -0500 Received: from mail-wm0-f65.google.com ([74.125.82.65]:35676 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750776AbcKGMSO (ORCPT ); Mon, 7 Nov 2016 07:18:14 -0500 MIME-Version: 1.0 In-Reply-To: <62f150ba-abc0-8e45-1355-8a61354ee3e1@axentia.se> References: <1477262381-7800-1-git-send-email-peda@axentia.se> <1477262381-7800-2-git-send-email-peda@axentia.se> <62f150ba-abc0-8e45-1355-8a61354ee3e1@axentia.se> From: Daniel Baluta Date: Mon, 7 Nov 2016 14:18:12 +0200 Message-ID: Subject: Re: [PATCH v3 1/8] iio:core: add a callback to allow drivers to provide _available attributes To: Peter Rosin Cc: Linux Kernel Mailing List , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Rob Herring , Mark Rutland , "linux-iio@vger.kernel.org" , Devicetree List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2083 Lines: 56 On Mon, Nov 7, 2016 at 1:57 PM, Peter Rosin wrote: > On 2016-11-07 12:37, Daniel Baluta wrote: >> On Mon, Oct 24, 2016 at 1:39 AM, Peter Rosin wrote: >>> From: Jonathan Cameron >>> >>> A large number of attributes can only take a limited range of values. >>> Currently in IIO this is handled by directly registering additional >>> *_available attributes thus providing this information to userspace. >>> >>> It is desirable to provide this information via the core for much the same >>> reason this was done for the actual channel information attributes in the >>> first place. If it isn't there, then it can only really be accessed from >>> userspace. Other in kernel IIO consumers have no access to what valid >>> parameters are. >>> >>> Two forms are currently supported: >>> * list of values in one particular IIO_VAL_* format. >>> e.g. 1.300000 1.500000 1.730000 >>> * range specification with a step size: >>> e.g. [1.000000 0.500000 2.500000] >>> equivalent to 1.000000 1.5000000 2.000000 2.500000 >> >> Is there any driver using this format? :) > > Yes, soon. Hopefully. See patch 3/8 > iio: mcp4531: provide range of available raw values > https://patchwork.kernel.org/patch/9391283/ > >>> >>> An addition set of masks are used to allow different sharing rules for the >>> *_available attributes generated. >>> >>> This allows for example: >>> >>> in_accel_x_offset >>> in_accel_y_offset >>> in_accel_offset_available. >>> >>> We could have gone with having a specification for each and every >>> info_mask element but that would have meant changing the existing userspace >>> ABI. This approach does not. >>> >>> Signed-off-by: Jonathan Cameron >>> [forward ported, added some docs and fixed buffer overflows /peda] >>> Signed-off-by: Peter Rosin >> >> The patch looks good to me at a first glance. > > Thanks, may I add your acked-by if/when I respin? Yes. You can have it from here: Acked-by: Daniel Baluta thanks, Daniel.