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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02E52C6FA82 for ; Thu, 22 Sep 2022 12:18:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229496AbiIVMSo (ORCPT ); Thu, 22 Sep 2022 08:18:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231273AbiIVMSf (ORCPT ); Thu, 22 Sep 2022 08:18:35 -0400 Received: from smtp1.axis.com (smtp1.axis.com [195.60.68.17]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0FFB3E62CE for ; Thu, 22 Sep 2022 05:18:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axis.com; q=dns/txt; s=axis-central1; t=1663849114; x=1695385114; h=date:to:cc:subject:message-id:references:mime-version: content-transfer-encoding:in-reply-to:from; bh=Nem9zPrz5bOyr19zdGKAw5KYgpl9PDHyvMFldMrZaeE=; b=UDajOOJdiF9muN7tQTnjO/8rB+pXqdSxjZ4RViW5LbpCbtqd/HPoW+Ho RHKv5JR8HzkfITA6CrDFr3MH4GVNsANmQAMvOQ/YCSgt6uKtVzfjycCrV wWsstdESSjmNaDFYGLm1oj9DKUAJg/SY+IVCdmkbfUTU+NhKEEuCM0jRq qex8wbeDCUWJARNzpUBSBIHjxMxpgGas8AVqZa0LWh0prKvVOJmOPSylF YsC/xEd+BbSSjC3bovsZKz+pgdGRHCKg9fjcvzDKs3Wm10pYgj/VrBOu2 DjKCqbycSCz8BZHrB5Ou9upTvMfuM+Eb2aLiysFw5jzZlpmCfNlPxcMMx w==; Date: Thu, 22 Sep 2022 14:18:31 +0200 To: Paul Cercueil CC: =?iso-8859-1?Q?M=E5rten?= Lindahl , Jonathan Cameron , Lars-Peter Clausen , Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , "linux-iio@vger.kernel.org" , kernel Subject: Re: [PATCH 1/3] iio: light: vcnl4000: Preserve conf bits when toggle power Message-ID: References: <20220920180958.2308229-1-marten.lindahl@axis.com> <20220920180958.2308229-2-marten.lindahl@axis.com> <2V4JIR.7354DS8U39Q53@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2V4JIR.7354DS8U39Q53@crapouillou.net> From: Marten Lindahl Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Wed, Sep 21, 2022 at 12:23:26AM +0200, Paul Cercueil wrote: > Hi Mårten, > > Le mar., sept. 20 2022 at 20:09:56 +0200, Mårten Lindahl > a écrit : > > As the vcnl4040 and vcnl4200 chip uses runtime power management for > > turning the ambient light and proximity sensors on/off, it overwrites > > the entire register each time. In ALS_CONF register bit fields ALS_IT, > > ALS_PERS, ALS_INT_EN are overwritten. In PS_CONF1 register bit fields > > PS_DUTY, PS_PERS, PS_IT, PS_HD, and PS_INT are overwritten. > > > > Add functions for preserving the affected bit fields when changing > > power > > state. > > > > Signed-off-by: Mårten Lindahl > > --- > > drivers/iio/light/vcnl4000.c | 53 > > ++++++++++++++++++++++++++++++++++-- > > 1 file changed, 51 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/iio/light/vcnl4000.c > > b/drivers/iio/light/vcnl4000.c > > index 3db4e26731bb..0b226c684957 100644 > > --- a/drivers/iio/light/vcnl4000.c > > +++ b/drivers/iio/light/vcnl4000.c > > @@ -74,6 +74,9 @@ > > #define VCNL4000_PROX_EN BIT(1) /* start proximity measurement */ > > #define VCNL4000_SELF_TIMED_EN BIT(0) /* start self-timed > > measurement */ > > > > +#define VCNL4040_ALS_CONF_ALS_SD BIT(0) /* Enable ambient light > > sensor */ > > +#define VCNL4040_PS_CONF1_PS_SD BIT(0) /* Enable proximity sensor */ > > + > > /* Bit masks for interrupt registers. */ > > #define VCNL4010_INT_THR_SEL BIT(0) /* Select threshold interrupt > > source */ > > #define VCNL4010_INT_THR_EN BIT(1) /* Threshold interrupt type */ > > @@ -188,16 +191,62 @@ static int vcnl4000_init(struct vcnl4000_data > > *data) > > return data->chip_spec->set_power_state(data, true); > > }; > > > > +static ssize_t vcnl4000_write_als_enable(struct vcnl4000_data *data, > > int val) > > +{ > > + int ret; > > + > > + switch (data->id) { > > + case VCNL4040: > > + case VCNL4200: Hi Paul! Thanks for looking at this! > > The switch isn't needed, since vcnl4200_set_power_state() is only > called for compatible chips. Yes, your're right. I will remove the switch. > > > + ret = i2c_smbus_read_word_data(data->client, VCNL4200_AL_CONF); > > + if (ret < 0) > > + return ret; > > + > > + if (val) > > + ret &= ~VCNL4040_ALS_CONF_ALS_SD; > > + else > > + ret |= VCNL4040_ALS_CONF_ALS_SD; > > + > > + return i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF, > > + ret); > > Are you sure a race cannot happen here? > > I would assume it cannot, but that's still a bit fishy. Ok, I see what you mean. I cannot tell for sure, but I can guard the read and write with the mutex. > > This driver would benefit from a regmap conversion, but it's probably a > bit too much to ask... I can try to do this in a separate patch after these ones if that's ok? > > > + default: > > + return -EINVAL; > > + } > > +} > > + > > +static ssize_t vcnl4000_write_ps_enable(struct vcnl4000_data *data, > > int val) > > +{ > > + int ret; > > + > > + switch (data->id) { > > + case VCNL4040: > > + case VCNL4200: > > + ret = i2c_smbus_read_word_data(data->client, VCNL4200_PS_CONF1); > > + if (ret < 0) > > + return ret; > > + > > + if (val) > > + ret &= ~VCNL4040_PS_CONF1_PS_SD; > > + else > > + ret |= VCNL4040_PS_CONF1_PS_SD; > > + > > + return i2c_smbus_write_word_data(data->client, > > + VCNL4200_PS_CONF1, ret); > > + default: > > + return -EINVAL; > > + } > > +} > > + > > static int vcnl4200_set_power_state(struct vcnl4000_data *data, bool > > on) > > { > > u16 val = on ? 0 /* power on */ : 1 /* shut down */; > > int ret; > > > > - ret = i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF, > > val); > > + ret = vcnl4000_write_als_enable(data, !val); > > You set "val" to 0 if "on", and to 1 if "!on", then pass "!val", this > is very confusing. You could just pass "on" here and below. I agree! I will change it to only use the boolean 'on'. Kind reagards Mårten > > Cheers, > -Paul > > > if (ret < 0) > > return ret; > > > > - ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, > > val); > > + ret = vcnl4000_write_ps_enable(data, !val); > > if (ret < 0) > > return ret; > > > > -- > > 2.30.2 > > > >