From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754602AbbKQTZj (ORCPT ); Tue, 17 Nov 2015 14:25:39 -0500 Received: from mout01.posteo.de ([185.67.36.65]:56567 "EHLO mout01.posteo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751557AbbKQTZg (ORCPT ); Tue, 17 Nov 2015 14:25:36 -0500 Message-ID: <564B7F02.4020709@posteo.de> Date: Tue, 17 Nov 2015 20:24:50 +0100 From: Martin Kepplinger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.8.0 MIME-Version: 1.0 To: Jonathan Cameron , knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, christoph.muellner@theobroma-systems.com, mfuzzey@parkeon.com CC: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Martin Kepplinger Subject: Re: [PATCH 1/3] iio: mma8452: add freefall detection for Freescale's accelerometers References: <1447267094-2248-1-git-send-email-martink@posteo.de> <5647778E.3090106@kernel.org> <56478136.3040200@posteo.de> <5647857D.5050902@kernel.org> In-Reply-To: <5647857D.5050902@kernel.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 2015-11-14 um 20:03 schrieb Jonathan Cameron: > On 14/11/15 18:45, Martin Kepplinger wrote: >> Am 2015-11-14 um 19:03 schrieb Jonathan Cameron: >>> On 11/11/15 18:38, Martin Kepplinger wrote: >>>> This adds freefall event detection to the supported devices. It adds >>>> the in_accel_x&y&z_mag_falling_en iio event attribute, which activates >>>> freefall mode. >>>> >>>> In freefall mode, the current acceleration values of all activated axis >>>> are added and if the *sum* falls *under* the threshold specified >>>> (in_accel_mag_falling_value), the appropriate IIO event code >>>> is generated. >>>> >>>> By enabling freefall mode (in_accel_x&y&z_mag_falling_en) >>>> all 3 axis are enabled too as this describes a classic freefall >>>> detection. Of course the user is free to disable one or more directions. >>>> >>>> The values of rising and falling versions of various sysfs files are >>>> shared, which is compliant to the IIO specification. >>>> >>>> This is what the sysfs "events" directory for these devices looks >>>> like after this change: >>>> >>>> -rw-r--r-- 4096 Oct 23 08:45 in_accel_mag_falling_period >>>> -rw-r--r-- 4096 Oct 23 08:45 in_accel_mag_falling_value >>>> -rw-r--r-- 4096 Oct 23 08:45 in_accel_mag_rising_period >>>> -rw-r--r-- 4096 Oct 23 08:45 in_accel_mag_rising_value >>>> -r--r--r-- 4096 Oct 23 08:45 in_accel_scale >>>> -rw-r--r-- 4096 Oct 23 08:45 in_accel_x&y&z_mag_falling_en >>>> -rw-r--r-- 4096 Oct 23 08:45 in_accel_x_mag_falling_en >>>> -rw-r--r-- 4096 Oct 23 08:45 in_accel_x_mag_rising_en >>>> -rw-r--r-- 4096 Oct 23 08:45 in_accel_y_mag_falling_en >>>> -rw-r--r-- 4096 Oct 23 08:45 in_accel_y_mag_rising_en >>>> -rw-r--r-- 4096 Oct 23 08:45 in_accel_z_mag_falling_en >>>> -rw-r--r-- 4096 Oct 23 08:45 in_accel_z_mag_rising_en >>>> >>>> Signed-off-by: Martin Kepplinger >>>> Signed-off-by: Christoph Muellner >>> Looks pretty good to me (other than obviously the bits Lars already >>> picked up on!) >>> >>> My only real comment was that you could do the rest of the combined >>> possibilities whilst you are here (if you want to!) You've >>> picked the mostly obviously useful one though so maybe leave it >>> at that. >> >> I'm not sure what you mean. There is only in_accel_x&y&z_mag_falling_en >> documented. So my guess was to have this to enable freefall mode, taking >> into account the currently enabled falling axis >> (in_accel_x_mag_falling_en, ...). > Sure, but the set of modifiers allows for > in_accel_x&y_mag_falling_* etc and they aren't documented in this particular > form simply because no driver has used them yet ;) > I don't see how to do it in iio_event_spec only. Could you point me in the right direction, could well be I overlook something... I *can* add a channel for freefall purposes, something like: static const struct iio_chan_spec mma8653_channels[] = { MMA8652_CHANNEL(IIO_MOD_X, idx_axis_x, 10), MMA8652_CHANNEL(IIO_MOD_Y, idx_axis_y, 10), MMA8652_CHANNEL(IIO_MOD_Z, idx_axis_z, 10), MMA8652_CHANNEL(IIO_MOD_X_AND_Y_AND_Z, idx_axis_xyz, 10), IIO_CHAN_SOFT_TIMESTAMP(idx_timestamp), }; just as an example, but then of course I get more than just events: In the device-directory: in_accel_x&y&z_calibbias in_accel_x&y&z_raw in_accel_x_calibbias in_accel_x_raw in_accel_y_calibbias in_accel_y_raw in_accel_z_calibbias in_accel_z_raw calibbias and raw are not (really) available for x&y&z. I could calculate a "raw" value, but calibbias doesn't make sense here. ...But again, maybe I'm on the wrong path!! thanks a lot! martin