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-rw-r--r--Documentation/devicetree/bindings/arm/arm,scpi.txt38
1 files changed, 38 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/arm,scpi.txt b/Documentation/devicetree/bindings/arm/arm,scpi.txt
index f0024605f416..86302de67c2c 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.