Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753247AbbK2Ogq (ORCPT ); Sun, 29 Nov 2015 09:36:46 -0500 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:43907 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753216AbbK2Ogm (ORCPT ); Sun, 29 Nov 2015 09:36:42 -0500 Subject: Re: [PATCH 2/5] Documentation: devicetree: Add property for controlling power saving mode for the us5182 als sensor To: Rob Herring , Adriana Reus References: <1448362792-5181-1-git-send-email-adriana.reus@intel.com> <1448362792-5181-3-git-send-email-adriana.reus@intel.com> <20151125000130.GA21418@rob-hp-laptop> <56558466.9000001@intel.com> <20151125235526.GA21218@rob-hp-laptop> Cc: linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, pawel.moll@arm.com, pmeerw@pmeerw.net, lars@metafoo.de From: Jonathan Cameron Message-ID: <565B0D78.6010707@kernel.org> Date: Sun, 29 Nov 2015 14:36:40 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151125235526.GA21218@rob-hp-laptop> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4062 Lines: 89 On 25/11/15 23:55, Rob Herring wrote: > On Wed, Nov 25, 2015 at 11:50:30AM +0200, Adriana Reus wrote: >> >> >> On 25.11.2015 02:01, Rob Herring wrote: >>> On Tue, Nov 24, 2015 at 12:59:49PM +0200, Adriana Reus wrote: >>>> Add a property to allow changing the default power-saving mode. >>>> By default, at read raw the chip will activate and provide >>>> one measurent, then it will shut itself down. However, the >>>> chip can also work in "continuous" mode which may be more reliable >>>> but is also more power consuming. >>>> >>>> Signed-off-by: Adriana Reus >>>> --- >>>> Documentation/devicetree/bindings/iio/light/us5182d.txt | 11 +++++++++++ >>>> 1 file changed, 11 insertions(+) >>>> >>>> diff --git a/Documentation/devicetree/bindings/iio/light/us5182d.txt b/Documentation/devicetree/bindings/iio/light/us5182d.txt >>>> index 6f0a530..a619799 100644 >>>> --- a/Documentation/devicetree/bindings/iio/light/us5182d.txt >>>> +++ b/Documentation/devicetree/bindings/iio/light/us5182d.txt >>>> @@ -7,13 +7,24 @@ Required properties: >>>> Optional properties: >>>> - upisemi,glass-coef: glass attenuation factor - compensation factor of >>>> resolution 1000 for material transmittance. >>>> + >>>> - upisemi,dark-ths: array of 8 elements containing 16-bit thresholds (adc >>>> counts) corresponding to every scale. >>>> + >>>> - upisemi,upper-dark-gain: 8-bit dark gain compensation factor(4 int and 4 >>>> fractional bits - Q4.4) applied when light > threshold >>>> + >>>> - upisemi,lower-dark-gain: 8-bit dark gain compensation factor(4 int and 4 >>>> fractional bits - Q4.4) applied when light < threshold >>>> >>>> +- upisemi,continuous: This chip has two power modes: one-shot (chip takes one >>>> + measurement and then shuts itself down) and continuous ( >>>> + chip takes continuous measurements). The one-shot mode is >>>> + more power-friendly but the continuous mode may be more >>>> + reliable. If this property is specified the continuous >>>> + mode will be used instead of the default one-shot one for >>>> + raw reads. >>> >>> I could imagine an OS may want to decide this on its own or use a >>> mixture of the modes. >>> >>> Rob >>> >> >> There is no possibility of mixing them up (at the same time), so for example >> proximity cannot work in one mode and als the other. >> >> The one-shot mode can only be used for raw reads (for example when >> user-space polls in_[proximity|light]_raw). If user-space wants to enable >> events (activate interrupts when certain thresholds are met - patch 5 of the >> series), then the chip has to switch to continuous nonetheless because it >> needs to be active all the time. So one work-flow scenario would be: >> >> Consumer1 starts polling the raw interface - default_mode >> Consumer2 activates events - continuous mode >> Consumer2 deactivates events - back to default_mode >> >> The only choice here is the default mode for raw reads, it currently is >> one-shot, this patch allows for continuous to be used if preferred. > > Okay, then: > > Acked-by: Rob Herring Applied to the togreg branch of iio.git - initially pushed out as testing. Thanks, Jonathan > >> -- >> To unsubscribe from this list: send the line "unsubscribe devicetree" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- 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/