This binding adds description for interface supporting
aspeed-pwm-tacho driver cooling device creation.
This cooling device could be bound to a thermal zone
for the thermal control.
It adds extra level of hierarchy - for tachometer channel
with fan subnodes and pwm channels with pwm subnodes.
Signed-off-by: Mykola Kostenok <c_mykolak@xxxxxxxxxxxx>
---
.../devicetree/bindings/hwmon/aspeed-pwm-tacho.txt | 56 ++++++++++++++++++----
1 file changed, 47 insertions(+), 9 deletions(-)
diff --git a/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt b/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt
index cf4460564adb..df85aa70ed7f 100644
--- a/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt
+++ b/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt
@@ -23,9 +23,18 @@ Required properties for pwm-tacho node:
- clocks : a fixed clock providing input clock frequency(PWM
and Fan Tach clock)
+tach-channels subnode format:
+===================
+Under tach-channels subnode there can be fan child nodes.
+
+Required properties for tach-channels node:
+- #address-cells : should be 1.
+
+- #size-cells : should be 0.
+
fan subnode format:
===================
-Under fan subnode there can upto 8 child nodes, with each child node
+Under fan subnode there can be upto 8 child nodes, with each child node
representing a fan. If there are 8 fans each fan can have one PWM port and
one/two Fan tach inputs.
@@ -39,6 +48,24 @@ Required properties for each child node:
Fan tach channel 0 and 15 indicating Fan tach channel 15.
Atleast one Fan tach input channel is required.
+pwm-channels subnode format:
+===================
+Under pwm-channels subnode there can be pwm child nodes.
+Required properties for tach-channels node:
+- #address-cells : should be 1.
+
+- #size-cells : should be 0.
+
+- #cooling-cells : should be 2;
+
+pwm subnode format:
+===================
+- reg : should be <0x00>.
+
+- cooling-levels : PWM duty cycle values in a range from 0 to 255
+ which correspond to thermal cooling states.
+
+
Examples:
pwm_tacho_fixed_clk: fixedclk {
@@ -55,14 +82,25 @@ pwm_tacho: pwmtachocontroller@1e786000 {
clocks = <&pwm_tacho_fixed_clk>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_pwm0_default &pinctrl_pwm1_default>;
-
- fan@0 {
- reg = <0x00>;
- aspeed,fan-tach-ch = /bits/ 8 <0x00>;
+ tach-channels {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ fan@0 {
+ reg = <0x00>;
+ aspeed,fan-tach-ch = /bits/ 8 <0x00>;
+ };
+ fan@1 {
+ reg = <0x01>;
+ aspeed,fan-tach-ch = /bits/ 8 <0x01 0x02>;
+ };
};
-
- fan@1 {
- reg = <0x01>;
- aspeed,fan-tach-ch = /bits/ 8 <0x01 0x02>;
+ pwm-channels {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ #cooling-cells = <2>;
+ pwm@0 {
+ reg = <0x00>;
+ cooling-levels = /bits/ 8 <125 151 177 203 229 255>;
+ };
};
};
--
2.11.0
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