From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758111AbbIVOcg (ORCPT ); Tue, 22 Sep 2015 10:32:36 -0400 Received: from fw-tnat.cambridge.arm.com ([217.140.96.140]:56404 "EHLO cam-smtp0.cambridge.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757882AbbIVOce (ORCPT ); Tue, 22 Sep 2015 10:32:34 -0400 From: Punit Agrawal To: linux-arm-kernel@lists.infradead.org Cc: devicetree@vger.kernel.org, mark.rutland@arm.com, liviu.dudau@arm.com, linux-kernel@vger.kernel.org, edubezval@gmail.com, robh+dt@kernel.org, sudeep.holla@arm.com, linux@roeck-us.net Subject: Re: [PATCH v4 1/5] Documentation: add DT bindings for ARM SCPI sensors In-Reply-To: <1442335861-7282-2-git-send-email-punit.agrawal@arm.com> (Punit Agrawal's message of "Tue, 15 Sep 2015 17:50:57 +0100") References: <1442335861-7282-1-git-send-email-punit.agrawal@arm.com> <1442335861-7282-2-git-send-email-punit.agrawal@arm.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) Date: Tue, 22 Sep 2015 15:31:53 +0100 Message-ID: <9hhoagubk4m.fsf@e105922-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Punit Agrawal writes: > The System Control Processor (SCP) provides access to SoC sensors via > the System Control and Power Interface (SCPI) Message Protocol. Add > bindings to allow probing of these sensors. Also support referencing > of the sensors for setting up thermal zones via the thermal DT > bindings. > > Signed-off-by: Punit Agrawal > Cc: Rob Herring > Cc: Mark Rutland > Cc: Sudeep Holla Gentle reminder for review of the below bindings. They've been updated based on feedback on the earlier version [a]. If there are no further comments, I'd like to request an ack from the DT reviewers. [a] http://thread.gmane.org/gmane.linux.power-management.general/65475/focus=134976 > --- > Documentation/devicetree/bindings/arm/arm,scpi.txt | 38 ++++++++++++++++++++++ > 1 file changed, 38 insertions(+) > > diff --git a/Documentation/devicetree/bindings/arm/arm,scpi.txt b/Documentation/devicetree/bindings/arm/arm,scpi.txt > index f002460..86302de 100644 > --- a/Documentation/devicetree/bindings/arm/arm,scpi.txt > +++ b/Documentation/devicetree/bindings/arm/arm,scpi.txt > @@ -72,8 +72,25 @@ Required sub-node properties: > - compatible : should be "arm,juno-scp-shmem" for Non-secure SRAM based > shared memory on Juno platforms > > +Sensor bindings for the sensors based on SCPI Message Protocol > +-------------------------------------------------------------- > +SCPI provides an API to access the various sensors on the SoC. > + > +Required properties: > +- compatible : should be "arm,scpi-sensors". > +- #thermal-sensor-cells: should be set to 1. This property follows the > + thermal device tree bindings[2]. > + > + Valid cell values are raw identifiers (Sensor > + ID) as used by the firmware. Refer to > + platform documentation for your > + implementation for the IDs to use. For Juno > + R0 and Juno R1 refer to [3]. > + > [0] http://infocenter.arm.com/help/topic/com.arm.doc.dui0922b/index.html > [1] Documentation/devicetree/bindings/clock/clock-bindings.txt > +[2] Documentation/devicetree/bindings/thermal/thermal.txt > +[3] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0922b/apas03s22.html > > Example: > > @@ -122,6 +139,11 @@ scpi_protocol: scpi@2e000000 { > clock-output-names = "pxlclk0", "pxlclk1"; > }; > }; > + > + scpi_sensors0: sensors { > + compatible = "arm,scpi-sensors"; > + #thermal-sensor-cells = <1>; > + }; > }; > > cpu@0 { > @@ -136,6 +158,17 @@ hdlcd@7ff60000 { > clocks = <&scpi_clk 4>; > }; > > +thermal-zones { > + soc_thermal { > + polling-delay-passive = <100>; > + polling-delay = <1000>; > + > + /* sensor ID */ > + thermal-sensors = <&scpi_sensors0 3>; > + ... > + }; > +}; > + > In the above example, the #clock-cells is set to 1 as required. > scpi_dvfs has 3 output clocks namely: atlclk, aplclk, and gpuclk with 0, > 1 and 2 as clock-indices. scpi_clk has 2 output clocks namely: pxlclk0 > @@ -148,3 +181,8 @@ scpi_dvfs i.e. "atlclk". > Similarly the second example is hdlcd@7ff60000 and it has pxlclk1 as input > clock. '4' in the clock specifier here points to the second entry > in the output clocks of scpi_clocks i.e. "pxlclk1" > + > +The thermal-sensors property in the soc_thermal node uses the > +temperature sensor provided by SCP firmware to setup a thermal > +zone. The ID "3" is the sensor identifier for the temperature sensor > +as used by the firmware.