dt-bindings: stm32-thermal: add binding documentation

Add thermal binding documentation for STM32 DTS sensor

Signed-off-by: David Hernandez Sanchez <david.hernandezsanchez@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/thermal/stm32-thermal.txt b/Documentation/devicetree/bindings/thermal/stm32-thermal.txt
new file mode 100644
index 000000000000..8c0d5a4d8031
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/stm32-thermal.txt
@@ -0,0 +1,61 @@
+Binding for Thermal Sensor for STMicroelectronics STM32 series of SoCs.
+
+On STM32 SoCs, the Digital Temperature Sensor (DTS) is in charge of managing an
+analog block which delivers a frequency depending on the internal SoC's
+temperature. By using a reference frequency, DTS is able to provide a sample
+number which can be translated into a temperature by the user.
+
+DTS provides interrupt notification mechanism by threshold. This mechanism
+offers two temperature trip points: passive and critical. The first is intended
+for passive cooling notification while the second is used for over-temperature
+reset.
+
+Required parameters:
+-------------------
+
+compatible:     Should be "st,stm32-thermal"
+reg:            This should be the physical base address and length of the
+                sensor's registers.
+clocks:         Phandle of the clock used by the thermal sensor.
+                  See: Documentation/devicetree/bindings/clock/clock-bindings.txt
+clock-names:    Should be "pclk" for register access clock and reference clock.
+                  See: Documentation/devicetree/bindings/resource-names.txt
+#thermal-sensor-cells: Should be 0. See ./thermal.txt for a description.
+interrupts:     Standard way to define interrupt number.
+
+Example:
+
+        thermal-zones {
+                cpu_thermal: cpu-thermal {
+                        polling-delay-passive = <0>;
+                        polling-delay = <0>;
+
+                        thermal-sensors = <&thermal>;
+
+                        trips {
+                                cpu_alert1: cpu-alert1 {
+                                        temperature = <85000>;
+                                        hysteresis = <0>;
+                                        type = "passive";
+                                };
+
+                                cpu-crit: cpu-crit {
+                                        temperature = <120000>;
+                                        hysteresis = <0>;
+                                        type = "critical";
+                                };
+                        };
+
+                        cooling-maps {
+                        };
+                };
+        };
+
+        thermal: thermal@50028000 {
+                compatible = "st,stm32-thermal";
+                reg = <0x50028000 0x100>;
+                clocks = <&rcc TMPSENS>;
+                clock-names = "pclk";
+                #thermal-sensor-cells = <0>;
+                interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_HIGH>;
+        };