[patch v2] Documentation: dt-bindings: aspeed-pwm-tacho cooling device.

[Mykola Kostenok]

This controller supports fan tacho channels and pwm channels.
Without this change only tachometer channels can be configured.
Add extra level of hierarchy - for tachometer channel
with fan subnodes and pwm channels with pwm subnodes.

It's add support for cooling device creation to
aspeed-pwm-tacho.
Cooling device could be bound to a thermal zone
for the thermal control.

v1 -> v2:
 - Fix commit message.

Signed-off-by: Mykola Kostenok <c_mykolak at mellanox.com>
---
 .../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 cf44605..df85aa7 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 at 1e786000 {
 	clocks = <&pwm_tacho_fixed_clk>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_pwm0_default &pinctrl_pwm1_default>;
-
-	fan at 0 {
-		reg = <0x00>;
-		aspeed,fan-tach-ch = /bits/ 8 <0x00>;
+	tach-channels {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		fan at 0 {
+			reg = <0x00>;
+			aspeed,fan-tach-ch = /bits/ 8 <0x00>;
+		};
+		fan at 1 {
+			reg = <0x01>;
+			aspeed,fan-tach-ch = /bits/ 8 <0x01 0x02>;
+		};
 	};
-
-	fan at 1 {
-		reg = <0x01>;
-		aspeed,fan-tach-ch = /bits/ 8 <0x01 0x02>;
+	pwm-channels {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		#cooling-cells = <2>;
+		pwm at 0 {
+			reg = <0x00>;
+			cooling-levels = /bits/ 8 <125 151 177 203 229 255>;
+		};
 	};
 };
-- 
2.8.4