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=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 282F1C4741F for ; Wed, 4 Nov 2020 22:27:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E34F320756 for ; Wed, 4 Nov 2020 22:27:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732148AbgKDW1B (ORCPT ); Wed, 4 Nov 2020 17:27:01 -0500 Received: from mslow2.mail.gandi.net ([217.70.178.242]:46628 "EHLO mslow2.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728565AbgKDW06 (ORCPT ); Wed, 4 Nov 2020 17:26:58 -0500 Received: from relay4-d.mail.gandi.net (unknown [217.70.183.196]) by mslow2.mail.gandi.net (Postfix) with ESMTP id 122733A0782; Wed, 4 Nov 2020 22:25:36 +0000 (UTC) Received: from webmail.gandi.net (webmail15.sd4.0x35.net [10.200.201.15]) (Authenticated sender: contact@artur-rojek.eu) by relay4-d.mail.gandi.net (Postfix) with ESMTPA id D427CE0006; Wed, 4 Nov 2020 22:25:12 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 04 Nov 2020 23:25:12 +0100 From: Artur Rojek To: Paul Cercueil Cc: Jonathan Cameron , Lars-Peter Clausen , Peter Meerwald-Stadler , od@zcrc.me, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] iio/adc: ingenic: Fix AUX/VBAT readings when touchscreen is used In-Reply-To: <20201103201238.161083-1-paul@crapouillou.net> References: <20201103201238.161083-1-paul@crapouillou.net> Message-ID: X-Sender: contact@artur-rojek.eu User-Agent: Roundcube Webmail/1.3.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Paul, On 2020-11-03 21:12, Paul Cercueil wrote: > When the command feature of the ADC is used, it is possible to program > the ADC, and specify at each step what input should be processed, and > in > comparison to what reference. > > This broke the AUX and battery readings when the touchscreen was > enabled, most likely because the CMD feature would change the VREF all > the time. > > Now, when AUX or battery are read, we temporarily disable the CMD > feature, which means that we won't get touchscreen readings in that > time > frame. But it now gives correct values for AUX / battery, and the > touchscreen isn't disabled for long enough to be an actual issue. > > Fixes: b96952f498db ("IIO: Ingenic JZ47xx: Add touchscreen mode.") > Cc: > Signed-off-by: Paul Cercueil > --- > drivers/iio/adc/ingenic-adc.c | 33 +++++++++++++++++++++++++++------ > 1 file changed, 27 insertions(+), 6 deletions(-) > > diff --git a/drivers/iio/adc/ingenic-adc.c > b/drivers/iio/adc/ingenic-adc.c > index 92b25083e23f..ecaff6a9b716 100644 > --- a/drivers/iio/adc/ingenic-adc.c > +++ b/drivers/iio/adc/ingenic-adc.c > @@ -177,13 +177,12 @@ static void ingenic_adc_set_config(struct > ingenic_adc *adc, > mutex_unlock(&adc->lock); > } > > -static void ingenic_adc_enable(struct ingenic_adc *adc, > - int engine, > - bool enabled) > +static void ingenic_adc_enable_unlocked(struct ingenic_adc *adc, > + int engine, > + bool enabled) > { > u8 val; > > - mutex_lock(&adc->lock); > val = readb(adc->base + JZ_ADC_REG_ENABLE); > > if (enabled) > @@ -192,20 +191,42 @@ static void ingenic_adc_enable(struct ingenic_adc > *adc, > val &= ~BIT(engine); > > writeb(val, adc->base + JZ_ADC_REG_ENABLE); > +} > + > +static void ingenic_adc_enable(struct ingenic_adc *adc, > + int engine, > + bool enabled) > +{ > + mutex_lock(&adc->lock); > + ingenic_adc_enable_unlocked(adc, engine, enabled); > mutex_unlock(&adc->lock); > } > > static int ingenic_adc_capture(struct ingenic_adc *adc, > int engine) > { > + u32 cfg; > u8 val; > int ret; > > - ingenic_adc_enable(adc, engine, true); > + /* > + * Disable CMD_SEL temporarily, because it causes wrong VBAT > readings, > + * probably due to the switch of VREF. We must keep the lock here to > + * avoid races with the buffer enable/disable functions. > + */ > + mutex_lock(&adc->lock); > + cfg = readl(adc->base + JZ_ADC_REG_CFG); > + writel(cfg & ~JZ_ADC_REG_CFG_CMD_SEL, adc->base + JZ_ADC_REG_CFG); > + > + Redundant empty line. > + ingenic_adc_enable_unlocked(adc, engine, true); > ret = readb_poll_timeout(adc->base + JZ_ADC_REG_ENABLE, val, > !(val & BIT(engine)), 250, 1000); > if (ret) > - ingenic_adc_enable(adc, engine, false); > + ingenic_adc_enable_unlocked(adc, engine, false); > + > + writel(cfg, adc->base + JZ_ADC_REG_CFG); > + mutex_unlock(&adc->lock); > > return ret; > } With the above nitpick corrected: Acked-by: Artur Rojek