From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751968AbaH1NVn (ORCPT ); Thu, 28 Aug 2014 09:21:43 -0400 Received: from mail-vc0-f172.google.com ([209.85.220.172]:51842 "EHLO mail-vc0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751744AbaH1NVl (ORCPT ); Thu, 28 Aug 2014 09:21:41 -0400 Date: Thu, 28 Aug 2014 09:21:37 -0400 From: Eduardo Valentin To: Wei Ni Cc: khali@linux-fr.org, linux@roeck-us.net, swarren@wwwdotorg.org, lm-sensors@lm-sensors.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 3/4] thermal: add more description for thermal-zones Message-ID: <20140828132135.GA17074@developer> References: <1408948188-4181-1-git-send-email-wni@nvidia.com> <1408948188-4181-4-git-send-email-wni@nvidia.com> <20140825110711.GA12349@developer> <53FBEE39.2020001@nvidia.com> <20140826121210.GB15219@developer> <53FD484F.7030504@nvidia.com> <20140827133217.GB15875@developer> <53FE8AC9.2070907@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53FE8AC9.2070907@nvidia.com> User-Agent: Mutt/1.5.22 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Wei, On Thu, Aug 28, 2014 at 09:50:01AM +0800, Wei Ni wrote: > On 08/27/2014 09:32 PM, Eduardo Valentin wrote: > > Hello Wei, > > > > On Wed, Aug 27, 2014 at 10:54:07AM +0800, Wei Ni wrote: > >> On 08/26/2014 08:12 PM, Eduardo Valentin wrote: > >>> On Tue, Aug 26, 2014 at 10:17:29AM +0800, Wei Ni wrote: > >>>> On 08/25/2014 07:07 PM, Eduardo Valentin wrote: > >>>>> Hello Wei Ni, > >>>>> > >>>>> On Mon, Aug 25, 2014 at 02:29:47PM +0800, Wei Ni wrote: > >>>>>> Add more description for the "polling-delay" property. > >>>>>> Set "trips" and "cooling maps" as optional property, because > >>>>>> if missing these two sub-nodes, the thermal zone device still > >>>>>> work properly. > >>>>>> > >>>>>> Signed-off-by: Wei Ni > >>>>>> --- > >>>>>> Documentation/devicetree/bindings/thermal/thermal.txt | 10 ++++++---- > >>>>>> 1 file changed, 6 insertions(+), 4 deletions(-) > >>>>>> > >>>>>> diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt > >>>>>> index f5db6b7..e3d3ed9 100644 > >>>>>> --- a/Documentation/devicetree/bindings/thermal/thermal.txt > >>>>>> +++ b/Documentation/devicetree/bindings/thermal/thermal.txt > >>>>>> @@ -136,8 +136,8 @@ containing trip nodes and one sub-node containing all the zone cooling maps. > >>>>>> > >>>>>> Required properties: > >>>>>> - polling-delay: The maximum number of milliseconds to wait between polls > >>>>>> - Type: unsigned when checking this thermal zone. > >>>>>> - Size: one cell > >>>>>> + Type: unsigned when checking this thermal zone. If this value is 0, the > >>>>>> + Size: one cell driver will not run polling queue, but just cancel it. > >>>>>> > >>>>> > >>>>> The description above is specific to Linux kernel implementation > >>>>> nomenclature. DT description needs to be OS agnostic. > >>>>> > >>>>>> - polling-delay-passive: The maximum number of milliseconds to wait > >>>>>> Type: unsigned between polls when performing passive cooling. > >>>>>> @@ -148,14 +148,16 @@ Required properties: > >>>>>> phandles + sensor > >>>>>> specifier > >>>>>> > >>>>>> +Optional property: > >>>>>> - trips: A sub-node which is a container of only trip point nodes > >>>>>> Type: sub-node required to describe the thermal zone. > >>>>>> > >>>>>> - cooling-maps: A sub-node which is a container of only cooling device > >>>>>> Type: sub-node map nodes, used to describe the relation between trips > >>>>>> - and cooling devices. > >>>>>> + and cooling devices. If missing the "trips" property, > >>>>>> + This sub-node will not be parsed, because no trips can > >>>>>> + be bound to cooling devices. > >>>>> > >>>>> Do you mean if the thermal zone misses the "trips" property? Actually, > >>>>> the binding describes both, cooling-maps and trips, as required > >>>>> properties. Thus, both needs to be in place to consider the thermal zone > >>>>> as a proper described zone. > >>>> > >>>> I moved the "trips" and "cooling-maps" to optional property, because if > >>>> missing these two properties, the thermal zone devices still can be > >>>> registered, and the driver can work properly, it has the basic function, > >>>> can read temperature from thermal sysfs, although it doesn't have trips > >>>> and bind with cooling devices. > >>> > >>> > >>> If a thermal zone is used only for monitoring, then I believe it lost > >>> its purpose. As Maybe a different framework shall be used, such as hwmon, > >>> for instance? > >> > >> Yes, if we only use it for monitoring, we can use hwmon. But we have > >> more functions base on these two thermal zone devices. We have a > >> skin-temperature driver, which used nct1008's remote and local > >> temperatures to estimator the skin temperature. As you know the thermal > >> framework is more powerful, the remote/local sensors can be register as > >> thermal zone, then the skin-temp driver can use thermal_zone_get_temp() > >> to read their temperatures and then estimator skin's temp. We also will > >> set trips and cooling devices for this skin-temp. > > > > In this case, don't you think it would make sense to create a thermal > > zone for the skin temperature and add the required sensors (including > > the nct1008) in it? > > Hi, Eduardo > Yes, we will create a thermal zone for the skin-temp driver and add the > required sensors in it, but in here we want to register these required > sensors as thermal zone devices, then the thermal framework can export > functions to read these sensors temperature. If use hwmon framework, it > can't export nct1008's internal sensors, such as remote/local sensors, > and no exported functions to read these temperatures. If we doesn't use > the thermal/of-thermal framework, we have to develop a new framework to > parse those sensor nodes, and I think this new one may only have slight > difference with current thermal framework. > If we set those two properties as optional property, then we can use it > in this case simply. > > The skin-temp nodes will something like this: > > skin_temp: therm-est { > compatible = "nvidia,tegra124-therm-est"; > > #thermal-sensor-cells = <0>; > > sub-devs { > dev@0 { > /* we need to register nct1008_remote as thermal zone devices, so that > it's easy to handle it by using thermal framework's exported functions. */ > dev = <&nct1008_remote>; > }; > dev@1 { > dev = <&nct1008_local>; > }; > }; > }; > > thermal-zones { > skin-therm { > polling-delay-passive = <15000> > polling-delay = <0>; > > thermal-sensors = <&skin_temp>; The binding allows you to add several sensors in one thermal zone. Please have a look on the example (c) of the thermal.txt binding description. It might be that what you want to do is actually: thermal-sensors = <&ntc1008_local>, <&ntc1008_remote>; > > trips { > }; > cooling-maps { > }; > }; > }; > > Wei. > > > >> > >> Wei. > >> > >>> > >>> The purpose of a thermal zone is to describe thermal behavior of a > >>> hardware. As it is mentioned in the thermal.txt file. > >>> > >>> > >>>> > >>>> Thanks. > >>>> Wei. > >>>> > >>>>> > >>>>>> > >>>>>> -Optional property: > >>>>>> - coefficients: An array of integers (one signed cell) containing > >>>>>> Type: array coefficients to compose a linear relation between > >>>>>> Elem size: one cell the sensors listed in the thermal-sensors property. > >>>>>> -- > >>>>>> 1.8.1.5 > >>>>>> > >>>> > >>> -- > >>> To unsubscribe from this list: send the line "unsubscribe linux-tegra" in > >>> the body of a message to majordomo@vger.kernel.org > >>> More majordomo info at http://vger.kernel.org/majordomo-info.html > >>> > >> >