Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751786AbbEFRha (ORCPT ); Wed, 6 May 2015 13:37:30 -0400 Received: from mail-wg0-f54.google.com ([74.125.82.54]:35097 "EHLO mail-wg0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751499AbbEFRh0 (ORCPT ); Wed, 6 May 2015 13:37:26 -0400 MIME-Version: 1.0 In-Reply-To: <554A4C6B.10703@kernel.org> 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> Date: Wed, 6 May 2015 20:37:25 +0300 X-Google-Sender-Auth: eaVnFf7erOqrfwiXRJmThNZ_cbE Message-ID: Subject: Re: [PATCH v5 3/4] iio: trigger: Introduce IIO hrtimer based trigger From: Daniel Baluta To: Jonathan Cameron Cc: Daniel Baluta , 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 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: 1883 Lines: 50 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/