From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C0DD8C18E57 for ; Sat, 5 Dec 2020 18:45:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A447B22E03 for ; Sat, 5 Dec 2020 18:45:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728182AbgLESoj (ORCPT ); Sat, 5 Dec 2020 13:44:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:36222 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728118AbgLESoZ (ORCPT ); Sat, 5 Dec 2020 13:44:25 -0500 Received: from archlinux (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6B4F422E03; Sat, 5 Dec 2020 18:06:35 +0000 (UTC) Date: Sat, 5 Dec 2020 18:06:31 +0000 From: Jonathan Cameron To: Gwendal Grignou Cc: lars@metafoo.de, linux-iio@vger.kernel.org Subject: Re: [PATCH] iio: hrtimer: Allow sub Hz granularity Message-ID: <20201205180631.004173e5@archlinux> In-Reply-To: <20201204194803.751866-1-gwendal@chromium.org> References: <20201204194803.751866-1-gwendal@chromium.org> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Fri, 4 Dec 2020 11:48:03 -0800 Gwendal Grignou wrote: > Allow setting frequency below 1Hz or sub 1Hz precision. > Useful for slow sensors like ALS. > > Test frequency is set properly: > modprobe iio-trig-hrtimer && \ > mkdir /sys/kernel/config/iio/triggers/hrtimer/t1 && \ > cd /sys/bus/iio/devices/triggerX ; > for i in 1 .1 .01 .001 ; do > echo $i > sampling_frequency > cat sampling_frequency > done > > Signed-off-by: Gwendal Grignou Looks good to me. I'd like this one to sit on the list a little longer though + it's missed this cycle anyway so we have plenty of time! Jonathan > --- > drivers/iio/trigger/iio-trig-hrtimer.c | 25 +++++++++++++++---------- > 1 file changed, 15 insertions(+), 10 deletions(-) > > diff --git a/drivers/iio/trigger/iio-trig-hrtimer.c b/drivers/iio/trigger/iio-trig-hrtimer.c > index a5e670726717f..06acd6dc79a8c 100644 > --- a/drivers/iio/trigger/iio-trig-hrtimer.c > +++ b/drivers/iio/trigger/iio-trig-hrtimer.c > @@ -22,7 +22,7 @@ > struct iio_hrtimer_info { > struct iio_sw_trigger swt; > struct hrtimer timer; > - unsigned long sampling_frequency; > + int sampling_frequency[2]; > ktime_t period; > }; > > @@ -38,7 +38,9 @@ ssize_t iio_hrtimer_show_sampling_frequency(struct device *dev, > struct iio_trigger *trig = to_iio_trigger(dev); > struct iio_hrtimer_info *info = iio_trigger_get_drvdata(trig); > > - return snprintf(buf, PAGE_SIZE, "%lu\n", info->sampling_frequency); > + return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, > + ARRAY_SIZE(info->sampling_frequency), > + info->sampling_frequency); > } > > static > @@ -48,18 +50,21 @@ ssize_t iio_hrtimer_store_sampling_frequency(struct device *dev, > { > struct iio_trigger *trig = to_iio_trigger(dev); > struct iio_hrtimer_info *info = iio_trigger_get_drvdata(trig); > - unsigned long val; > - int ret; > + unsigned long long val; > + int integer, fract, ret; > > - ret = kstrtoul(buf, 10, &val); > + ret = iio_str_to_fixpoint(buf, 100, &integer, &fract); > if (ret) > return ret; > > - if (!val || val > NSEC_PER_SEC) > + val = fract + 1000 * integer; > + > + if (!val || val > NSEC_PER_SEC * 1000) > return -EINVAL; > > - info->sampling_frequency = val; > - info->period = NSEC_PER_SEC / val; > + info->sampling_frequency[0] = integer; > + info->sampling_frequency[1] = fract * 1000; > + info->period = NSEC_PER_SEC * 1000 / val; > > return len; > } > @@ -135,8 +140,8 @@ static struct iio_sw_trigger *iio_trig_hrtimer_probe(const char *name) > hrtimer_init(&trig_info->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); > trig_info->timer.function = iio_hrtimer_trig_handler; > > - trig_info->sampling_frequency = HRTIMER_DEFAULT_SAMPLING_FREQUENCY; > - trig_info->period = NSEC_PER_SEC / trig_info->sampling_frequency; > + trig_info->sampling_frequency[0] = HRTIMER_DEFAULT_SAMPLING_FREQUENCY; > + trig_info->period = NSEC_PER_SEC / trig_info->sampling_frequency[0]; > > ret = iio_trigger_register(trig_info->swt.trigger); > if (ret)