[PATCH v4 1/5] Documentation: add DT bindings for ARM SCPI sensors

Punit Agrawal punit.agrawal at arm.com
Wed Sep 30 01:57:37 PDT 2015


Rob Herring <robh at kernel.org> writes:

> On Tue, Sep 15, 2015 at 11:50 AM, Punit Agrawal <punit.agrawal at arm.com> wrote:
>> 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 <punit.agrawal at arm.com>
>> Cc: Rob Herring <robh+dt at kernel.org>
>
> Acked-by: Rob Herring <robh at kernel.org>

Thanks, Rob!

Sudeep, now that we have acks for all the patches, are you OK to take
this patchset along with your series adding support for SCPI?

Punit

>
>> Cc: Mark Rutland <mark.rutland at arm.com>
>> Cc: Sudeep Holla <sudeep.holla at arm.com>
>> ---
>>  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 at 2e000000 {
>>                         clock-output-names = "pxlclk0", "pxlclk1";
>>                 };
>>         };
>> +
>> +       scpi_sensors0: sensors {
>> +               compatible = "arm,scpi-sensors";
>> +               #thermal-sensor-cells = <1>;
>> +       };
>>  };
>>
>>  cpu at 0 {
>> @@ -136,6 +158,17 @@ hdlcd at 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 at 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.
>> --
>> 2.5.1
>>
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