From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751747AbbEGJTf (ORCPT ); Thu, 7 May 2015 05:19:35 -0400 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:41055 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750924AbbEGJTc (ORCPT ); Thu, 7 May 2015 05:19:32 -0400 Message-ID: <554B2E22.10807@kernel.org> Date: Thu, 07 May 2015 10:19:30 +0100 From: Jonathan Cameron User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Daniel Baluta CC: Lars-Peter Clausen , Joel Becker , Hartmut Knaack , Linux Kernel Mailing List , "linux-iio@vger.kernel.org" , "octavian.purdila@intel.com" , Paul Bolle , patrick.porlan@intel.com, adriana.reus@intel.com, constantin.musca@intel.com, marten@intuitiveaerial.com Subject: Re: [PATCH v5 3/4] iio: trigger: Introduce IIO hrtimer based trigger References: <1430736604-22119-1-git-send-email-daniel.baluta@intel.com> <1430736604-22119-4-git-send-email-daniel.baluta@intel.com> <5547CE60.5000300@metafoo.de> <0944C1CC-6F9C-49C5-8195-994413B68680@kernel.org> <554A4065.8050101@intel.com> <554A4C6B.10703@kernel.org> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/05/15 18:37, Daniel Baluta wrote: > On Wed, May 6, 2015 at 8:16 PM, Jonathan Cameron wrote: >> On 06/05/15 17:25, Daniel Baluta wrote: >>> >>> >>> On 05/05/2015 04:51 PM, Jonathan Cameron wrote: >>>> >>>> >>>> On 4 May 2015 20:54:08 GMT+01:00, Lars-Peter Clausen wrote: >>>>> On 05/04/2015 12:50 PM, Daniel Baluta wrote: >>>>> [...] >>>>>> +IIO_HRTIMER_INFO_ATTR(sampling_frequency, S_IRUGO | S_IWUSR, >>>>>> + iio_hrtimer_info_show_sampling_frequency, >>>>>> + iio_hrtimer_info_store_sampling_frequency); >>>>> >>>>> I wonder if the sampling frequency should be configurable the regular >>>>> IIO >>>>> API, just like any other IIO device. But things like min/max sampling >>>>> frequency should be configured in configfs. >>>> Would have to be in the trigger dir rather than device... Makes sense to put it there. >>>> Limits on it here seem like a sensible idea. >>> >>> But then each trigger will have sampling_frequency right? This is not what we want. >> I'm confused now. Why not? Each hrtimer trigger created in configfs should have >> it's own sampling frequency should it not? > > I was referring to triggers in general, not just hrtimer triggers. > > But I see now that we can set trig->dev.groups to point to our > specific attributes. This > should work. > > Anyhow, I'm not convinced that sampling_frequency should be configured > from sysfs. > We create the trigger from configfs: > > $ mkdir /config/triggers/hrtimer-instance0 > > Then, likely we have to do something like this: > > $ echo 100 > /sys/bus/iio/trigger7/sampling_frequency > > How is the user application going to know which is the exact directory > for hrtimer-instance0 ? > > Daniel. > Find it by name like we normally do? J