Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752880AbbKQKpA (ORCPT ); Tue, 17 Nov 2015 05:45:00 -0500 Received: from mail-wm0-f45.google.com ([74.125.82.45]:37733 "EHLO mail-wm0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752102AbbKQKo3 (ORCPT ); Tue, 17 Nov 2015 05:44:29 -0500 From: Marc Titinger To: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net Cc: daniel.baluta@intel.com, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, Marc Titinger Subject: [RFC 1/2] ABI: iio: support AVERAGING_RATIO setting Date: Tue, 17 Nov 2015 11:44:09 +0100 Message-Id: <1447757050-4214-2-git-send-email-mtitinger@baylibre.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1447757050-4214-1-git-send-email-mtitinger@baylibre.com> References: <1447757050-4214-1-git-send-email-mtitinger@baylibre.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3882 Lines: 106 Some ADC devices allow averaging/downsampling. The minimal parameter set for this will be the number of taps used for computing a mean value. In some cases the ratio will hold discrete values for instance "1, 4, 16" hence an averaging_ratio_available property is useful. The possible ratio values are less likely to changing with the device settings, so this patch only provides a CONST version of the definition helper. Tested with ina226: # ls /sys/bus/iio/devices/iio\:device0/ averaging_ratio_available in_voltage0_raw dev in_voltage1_raw in_averaging_ratio name in_calibscale power in_current2_raw sampling_frequency_available in_power3_raw subsystem in_sampling_frequency uevent # cat averaging_ratio_available 1, 4, 16, 64, 128, 256, 512, 1024 Signed-off-by: Marc Titinger --- Documentation/ABI/testing/sysfs-bus-iio | 13 +++++++++++++ drivers/iio/industrialio-core.c | 1 + include/linux/iio/iio.h | 1 + include/linux/iio/sysfs.h | 9 +++++++++ 4 files changed, 24 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio index 42d360f..a208dfe 100644 --- a/Documentation/ABI/testing/sysfs-bus-iio +++ b/Documentation/ABI/testing/sysfs-bus-iio @@ -56,6 +56,19 @@ Description: When the internal sampling clock can only take a small discrete set of values, this file lists those available. +What: /sys/bus/iio/devices/iio:deviceX/averaging_ratio +KernelVersion: 4.x.x +Contact: linux-iio@vger.kernel.org +Description: + Hardware dependent ADC averaging. Controls the averaging ratio + of the digital filter if available. + +What: /sys/bus/iio/devices/iio:deviceX/averaging_ratio_available +KernelVersion: 4.x.x +Contact: linux-iio@vger.kernel.org +Description: + Hardware dependent values supported by the averaging filter. + What: /sys/bus/iio/devices/iio:deviceX/oversampling_ratio KernelVersion: 2.6.38 Contact: linux-iio@vger.kernel.org diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index b3fcc2c..e4745f0 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -142,6 +142,7 @@ static const char * const iio_chan_info_postfix[] = { [IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time", [IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity", [IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio", + [IIO_CHAN_INFO_AVERAGING_RATIO] = "averaging_ratio", }; /** diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 7bb7f67..4c84de5 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -46,6 +46,7 @@ enum iio_chan_info_enum { IIO_CHAN_INFO_DEBOUNCE_TIME, IIO_CHAN_INFO_CALIBEMISSIVITY, IIO_CHAN_INFO_OVERSAMPLING_RATIO, + IIO_CHAN_INFO_AVERAGING_RATIO, }; enum iio_shared_by { diff --git a/include/linux/iio/sysfs.h b/include/linux/iio/sysfs.h index 9cd8f74..4478ba1 100644 --- a/include/linux/iio/sysfs.h +++ b/include/linux/iio/sysfs.h @@ -76,6 +76,15 @@ struct iio_const_attr { /* Generic attributes of onetype or another */ /** + * IIO_CONST_ATTR_AVERAGING_RATIO_AVAIL - list available averaging ratios + * @_string: ratio string for the attribute + * + * Constant version + **/ +#define IIO_CONST_ATTR_AVERAGING_RATIO_AVAIL(_string) \ + IIO_CONST_ATTR(averaging_ratio_available, _string) + +/** * IIO_DEV_ATTR_SAMP_FREQ - sets any internal clock frequency * @_mode: sysfs file mode/permissions * @_show: output method for the attribute -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/