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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 603E5C432C3 for ; Sat, 16 Nov 2019 14:29:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C2012072D for ; Sat, 16 Nov 2019 14:29:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573914553; bh=1IueHVcc8RzQgw3S5/CF/JK96EkvFHZNKXMXy0CDNLE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=EVIA/xdfZoqOKy05nD1StS4D4CaQgK427IcVIBqXGY7ja5dFAuHpSAPeOLl0lFS60 kEpLkyhTUcF/FeGYkiNGDay6/5vtVIMlbbKKniZKrDmUJ3fhgwGeck1nWWfZXEVjFD ORoBMqs9rHFoAJnCE9D7wkKqgfaNGLIFjFAOR18E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727616AbfKPO3M (ORCPT ); Sat, 16 Nov 2019 09:29:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:58150 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727589AbfKPO3M (ORCPT ); Sat, 16 Nov 2019 09:29:12 -0500 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (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 DBC5320723; Sat, 16 Nov 2019 14:29:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573914551; bh=1IueHVcc8RzQgw3S5/CF/JK96EkvFHZNKXMXy0CDNLE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=0bUXZ2Dvuw4K3+E8GalD0rgUEx+UjvaCWmLafKnbhCW60TSWmwzPsC/no2qht6k3T ycPbrPR1v9CjJJ0aRJZ061K64CHMlcCYGye7dpFkWFa40tM5tdSsxQAgrNcmmcxwH3 9c9O+xVT+ngKCEwwn7IMkktjb2Xv/fU1eWRZHY+M= Date: Sat, 16 Nov 2019 14:29:05 +0000 From: Jonathan Cameron To: Matt Ranostay Cc: Andrea Merello , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Colin Ian King , Patrick Havelange , Paresh Chaudhary , Matt Weber , Chuhong Yuan , Daniel Gomez , "open list:IIO SUBSYSTEM AND DRIVERS" Subject: Re: [v2 1/9] iio: max31856: add option for setting mains filter rejection frequency Message-ID: <20191116142905.4368498e@archlinux> In-Reply-To: References: <20190923121714.13672-1-andrea.merello@gmail.com> <20191111153517.13862-1-andrea.merello@gmail.com> <20191111153517.13862-2-andrea.merello@gmail.com> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Tue, 12 Nov 2019 07:59:19 +0900 Matt Ranostay wrote: > On Tue, Nov 12, 2019 at 12:35 AM Andrea Merello > wrote: > > > > This sensor has an embedded notch filter for reducing interferences caused > > by the power mains. This filter can be tuned to reject either 50Hz or 60Hz > > (and harmonics). > > > > Currently the said setting is left alone (the sensor defaults to 60Hz). > > This patch introduces a IIO attribute that allows the user to set the said > > filter to the desired frequency. > > > > NOTE: this has been intentionally not tied to any DT property to allow > > the configuration of this setting from userspace, e.g. with a GUI or by > > reading a configuration file, or maybe reading a GPIO tied to a physical > > switch or accessing some device that can autodetect the line frequency. > > > > Looks good to me. Although this ideal could be a device tree property > as well, but not a big deal. > > Reviewed-by: Matt Ranostay I've no objection to someone following up with DT support for this as they might have a device that only supports one frequency of powersupply. However, let's leave it until we have a user that cares. I'm going to let the patch sit on the list a little longer though as it introduces new ABI and others may want to review. If I seem to have lost it in 2 weeks time give me a ping (normally I don't lose patches, but it's happened a few times in the past!) Thanks, Jonathan > > > Cc: Hartmut Knaack > > Cc: Lars-Peter Clausen > > Cc: Peter Meerwald-Stadler > > Cc: Colin Ian King > > Cc: Patrick Havelange > > Cc: Paresh Chaudhary > > Cc: Matt Weber > > Cc: Matt Ranostay > > Cc: Chuhong Yuan > > Cc: Daniel Gomez > > Cc: linux-iio@vger.kernel.org > > Signed-off-by: Andrea Merello > > --- > > drivers/iio/temperature/max31856.c | 50 ++++++++++++++++++++++++++++++ > > 1 file changed, 50 insertions(+) > > > > diff --git a/drivers/iio/temperature/max31856.c b/drivers/iio/temperature/max31856.c > > index 73ed550e3fc9..d97ba9ee1598 100644 > > --- a/drivers/iio/temperature/max31856.c > > +++ b/drivers/iio/temperature/max31856.c > > @@ -23,6 +23,7 @@ > > #define MAX31856_CR0_1SHOT BIT(6) > > #define MAX31856_CR0_OCFAULT BIT(4) > > #define MAX31856_CR0_OCFAULT_MASK GENMASK(5, 4) > > +#define MAX31856_CR0_FILTER_50HZ BIT(0) > > #define MAX31856_TC_TYPE_MASK GENMASK(3, 0) > > #define MAX31856_FAULT_OVUV BIT(1) > > #define MAX31856_FAULT_OPEN BIT(0) > > @@ -63,6 +64,7 @@ static const struct iio_chan_spec max31856_channels[] = { > > struct max31856_data { > > struct spi_device *spi; > > u32 thermocouple_type; > > + bool filter_50hz; > > }; > > > > static int max31856_read(struct max31856_data *data, u8 reg, > > @@ -123,6 +125,11 @@ static int max31856_init(struct max31856_data *data) > > reg_cr0_val &= ~MAX31856_CR0_1SHOT; > > reg_cr0_val |= MAX31856_CR0_AUTOCONVERT; > > > > + if (data->filter_50hz) > > + reg_cr0_val |= MAX31856_CR0_FILTER_50HZ; > > + else > > + reg_cr0_val &= ~MAX31856_CR0_FILTER_50HZ; > > + > > return max31856_write(data, MAX31856_CR0_REG, reg_cr0_val); > > } > > > > @@ -249,12 +256,54 @@ static ssize_t show_fault_oc(struct device *dev, > > return show_fault(dev, MAX31856_FAULT_OPEN, buf); > > } > > > > +static ssize_t show_filter(struct device *dev, > > + struct device_attribute *attr, > > + char *buf) > > +{ > > + struct iio_dev *indio_dev = dev_to_iio_dev(dev); > > + struct max31856_data *data = iio_priv(indio_dev); > > + > > + return sprintf(buf, "%d\n", data->filter_50hz ? 50 : 60); > > +} > > + > > +static ssize_t set_filter(struct device *dev, > > + struct device_attribute *attr, > > + const char *buf, > > + size_t len) > > +{ > > + struct iio_dev *indio_dev = dev_to_iio_dev(dev); > > + struct max31856_data *data = iio_priv(indio_dev); > > + unsigned int freq; > > + int ret; > > + > > + ret = kstrtouint(buf, 10, &freq); > > + if (ret) > > + return ret; > > + > > + switch (freq) { > > + case 50: > > + data->filter_50hz = true; > > + break; > > + case 60: > > + data->filter_50hz = false; > > + break; > > + default: > > + return -EINVAL; > > + } > > + > > + max31856_init(data); > > + return len; > > +} > > + > > static IIO_DEVICE_ATTR(fault_ovuv, 0444, show_fault_ovuv, NULL, 0); > > static IIO_DEVICE_ATTR(fault_oc, 0444, show_fault_oc, NULL, 0); > > +static IIO_DEVICE_ATTR(in_temp_filter_notch_center_frequency, 0644, > > + show_filter, set_filter, 0); > > > > static struct attribute *max31856_attributes[] = { > > &iio_dev_attr_fault_ovuv.dev_attr.attr, > > &iio_dev_attr_fault_oc.dev_attr.attr, > > + &iio_dev_attr_in_temp_filter_notch_center_frequency.dev_attr.attr, > > NULL, > > }; > > > > @@ -280,6 +329,7 @@ static int max31856_probe(struct spi_device *spi) > > > > data = iio_priv(indio_dev); > > data->spi = spi; > > + data->filter_50hz = false; > > > > spi_set_drvdata(spi, indio_dev); > > > > -- > > 2.17.1 > >