From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751606AbcADOR3 (ORCPT ); Mon, 4 Jan 2016 09:17:29 -0500 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:49093 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751374AbcADOR1 (ORCPT ); Mon, 4 Jan 2016 09:17:27 -0500 Date: Mon, 4 Jan 2016 15:17:09 +0100 From: Sascha Hauer To: Javi Merino Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, rui.zang@intel.com, edubezval@gmail.com, Zhang Rui , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , devicetree@vger.kernel.org Subject: Re: [PATCH v3 2/4] devicetree: bindings: let thermal-sensor point to other thermal zones Message-ID: <20160104141709.GB19256@pengutronix.de> References: <1448464186-26289-1-git-send-email-javi.merino@arm.com> <1448464186-26289-3-git-send-email-javi.merino@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1448464186-26289-3-git-send-email-javi.merino@arm.com> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 13:53:58 up 78 days, 21:32, 134 users, load average: 0.08, 0.06, 0.06 User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 25, 2015 at 03:09:44PM +0000, Javi Merino wrote: > The thermal-sensor property of the thermal zone node accepts phandles to > thermal sensors. However, thermal zones can be created as an > aggregation of other thermal zones. Extend the thermal-sensors property > to allow phandles to other thermal zones. This patch also adds an > example that showcases how a board thermal zone can be created from the > aggregation of the cpu, gpu and lcd thermal zones. > > Cc: Zhang Rui > Cc: Eduardo Valentin > Cc: Rob Herring > Cc: Pawel Moll > Cc: Mark Rutland > Cc: Ian Campbell > Cc: Kumar Gala > Cc: devicetree@vger.kernel.org > Signed-off-by: Javi Merino > --- > > Notes: > Hi devicetree, > > Is it ok to extend the definition of the thermal-sensors property like > this? IOW are phandles strongly typed? > > .../devicetree/bindings/thermal/thermal.txt | 154 ++++++++++++++++++++- > 1 file changed, 151 insertions(+), 3 deletions(-) > > diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt > index 41b817f7b670..52b7e9ae3b4d 100644 > --- a/Documentation/devicetree/bindings/thermal/thermal.txt > +++ b/Documentation/devicetree/bindings/thermal/thermal.txt > @@ -145,9 +145,12 @@ Required properties: > Size: one cell > > - thermal-sensors: A list of thermal sensor phandles and sensor specifier > - Type: list of used while monitoring the thermal zone. > - phandles + sensor > - specifier > + Type: list of used while monitoring the thermal zone. The phandles > + phandles + sensor can point to thermal sensors or other thermal zone > + specifier nodes. If it points to other thermal zone > + nodes you should omit the sensor specifier > + and set #thermal-sensor-cells to 0 for the > + thermal zone. > > - trips: A sub-node which is a container of only trip point nodes > Type: sub-node required to describe the thermal zone. > @@ -603,3 +606,148 @@ thermal-zones { > The above example is a mix of previous examples, a sensor IP with several internal > sensors used to monitor different zones, one of them is composed by several sensors and > with different cooling devices. > + > +(e) Board thermal with stacked thermal zones > + > +Instead of setting up one thermal zone combining multiple thermal > +zones and multiple trip points for each cooling device, we can create > +a hierarchy of thermal zones. > + > +#include > + > +&i2c1 { > + ... > + /* > + * An IC with several temperature sensor. > + */ > + adc_dummy: sensor@0x50 { > + ... > + #thermal-sensor-cells = <1>; /* sensor internal ID */ > + }; > +}; > + > +thermal-zones { > + > + cpu_thermal: cpu_thermal { > + polling-delay-passive = <1000>; /* milliseconds */ > + polling-delay = <2500>; /* milliseconds */ > + > + sustainable-power = <2500>; > + > + thermal-sensors = <&adc_dummy 0> > + > + trips { > + cpu_trip: cpu-trip { > + temperature = <60000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "passive"; > + }; > + }; > + > + cooling-maps { > + map0 { > + trip = <&cpu_trip>; > + cooling-device = <&cpu0 0 2>; > + }; > + }; > + }; > + > + gpu_thermal: gpu_thermal { > + polling-delay-passive = <1000>; /* milliseconds */ > + polling-delay = <2500>; /* milliseconds */ > + > + sustainable-power = <2500>; > + > + thermal-sensors = <&adc_dummy 2> > + > + trips { > + gpu_trip: gpu-trip { > + temperature = <55000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "passive"; > + } > + }; > + > + cooling-maps { > + map0 { > + trip = <&gpu_trip>; > + cooling-device = <&gpu0 0 2>; > + }; > + }; > + }; > + > + lcd_thermal: lcd_thermal { > + polling-delay-passive = <1000>; /* milliseconds */ > + polling-delay = <2500>; /* milliseconds */ > + > + sustainable-power = <2500>; > + > + thermal-sensors = <&adc_dummy 1> > + > + trips { > + lcd_trip: lcp-trip { > + temperature = <53000>; /* millicelsius */ > + hysteresis = <2000>; /* millicelsius */ > + type = "passive"; > + }; > + }; > + > + cooling-maps { > + map0 { > + trip = <&lcd_trip>; > + cooling-device = <&lcd0 5 10>; > + }; > + }; > + }; > + > + board_thermal: board-thermal { > + polling-delay-passive = <1000>; /* milliseconds */ > + polling-delay = <2500>; /* milliseconds */ > + > + thermal-sensors = <&cpu_thermal &gpu_thermal &lcd_thermal> This seems inconsistent. Why can a thermal zone only have multiple thermal sensors when they are thermal zones themselves? Either we assume that one thermal zone has a single sensor or we assume that it can have multiple sensors, but this should not depend on the zone being a sub zone or not. I think the thermal-sensors property should always point to one or multiple sensors. I see no point in "This property either points to exactly one sensor or multiple other thermal zones (from which we only use the temperature)" Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |