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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable 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 1C430C4320A for ; Thu, 2 Sep 2021 15:21:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1C05600AA for ; Thu, 2 Sep 2021 15:21:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345759AbhIBPWE convert rfc822-to-8bit (ORCPT ); Thu, 2 Sep 2021 11:22:04 -0400 Received: from relay11.mail.gandi.net ([217.70.178.231]:52117 "EHLO relay11.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239584AbhIBPWC (ORCPT ); Thu, 2 Sep 2021 11:22:02 -0400 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay11.mail.gandi.net (Postfix) with ESMTPSA id 4259C10000A; Thu, 2 Sep 2021 15:21:01 +0000 (UTC) Date: Thu, 2 Sep 2021 17:21:00 +0200 From: Miquel Raynal To: Jonathan Cameron Cc: Lars-Peter Clausen , Thomas Petazzoni , linux-iio@vger.kernel.org, Subject: Re: [PATCH 15/16] iio: adc: max1027: Support software triggers Message-ID: <20210902172100.3200b3b6@xps13> In-Reply-To: <20210830115046.3727ccc4@jic23-huawei> References: <20210818111139.330636-1-miquel.raynal@bootlin.com> <20210818111139.330636-16-miquel.raynal@bootlin.com> <20210830115046.3727ccc4@jic23-huawei> Organization: Bootlin X-Mailer: Claws Mail 3.17.7 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jonathan, Jonathan Cameron wrote on Mon, 30 Aug 2021 11:50:46 +0100: > On Wed, 18 Aug 2021 13:11:38 +0200 > Miquel Raynal wrote: > > > Now that max1027_trigger_handler() has been freed from handling hardware > > triggers EOC situations, we can use it for what it has been designed in > > the first place: trigger software originated conversions. > > As mentioned earlier, this is not how I'd normally expect this sort of > case to be handled. I'd be expecting the cnvst trigger to still be calling > this function and the function to do the relevant check to ensure it > knows the data is already available in that case. I tried to follow your advice and Nuno's regarding this, I hope the new version will match your expectations (new version coming soon). However if my changes do not match, I will probably need more guidance to understand in deep what you suggest. > > In other > > words, when userspace initiates a conversion with a sysfs trigger or a > > hrtimer trigger, we must do all configuration steps, ie: > > 1- Configuring the trigger > > 2- Configuring the channels to scan > > 3- Starting the conversion (actually done automatically by step 2 in > > this case) > > 4- Waiting for the conversion to end > > 5- Retrieving the data from the ADC > > 6- Push the data to the IIO core and notify it > > > > Add the missing steps to this helper and drop the trigger verification > > hook otherwise software triggers would simply not be accepted at all. > > > > Signed-off-by: Miquel Raynal > > --- > > drivers/iio/adc/max1027.c | 26 ++++++++++++++------------ > > 1 file changed, 14 insertions(+), 12 deletions(-) > > > > diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c > > index 8c5995ae59f2..bb437e43adaf 100644 > > --- a/drivers/iio/adc/max1027.c > > +++ b/drivers/iio/adc/max1027.c > > @@ -413,17 +413,6 @@ static int max1027_debugfs_reg_access(struct iio_dev *indio_dev, > > return spi_write(st->spi, val, 1); > > } > > > > -static int max1027_validate_trigger(struct iio_dev *indio_dev, > > - struct iio_trigger *trig) > > -{ > > - struct max1027_state *st = iio_priv(indio_dev); > > - > > - if (st->trig != trig) > > - return -EINVAL; > > - > > - return 0; > > -} > > - > > static int max1027_set_cnvst_trigger_state(struct iio_trigger *trig, bool state) > > { > > struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); > > @@ -512,7 +501,21 @@ static irqreturn_t max1027_trigger_handler(int irq, void *private) > > > > pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private); > > > > + ret = max1027_configure_trigger(indio_dev); > > I'd not expect to see this ever time. The configuration shouldn't change > from one call of this function to the next. True, this is not needed. > > + if (ret) > > + goto out; > > + > > + ret = max1027_configure_chans_to_scan(indio_dev); > > This should also not change unless it is also responsible for the 'go' signal. > If that's true then it is badly named. It's responsible for the go signal, I renamed it "configure_and_start". However, just for my own understanding, when would I be supposed to configure the channels requested by the user otherwise? Thanks, Miquèl