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[v3,3/8] Documentation: dts: Documentation entry to explain how to use PWM FAN as a cooling device

Message ID 1423241948-31981-4-git-send-email-l.majewski@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Lukasz Majewski Feb. 6, 2015, 4:59 p.m. UTC
Explanation of several properties, which allow PWM fan working as a cooling
device, have been embraced in this commit.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
---
Changes for v2:
- Rename cooling-pwm-values to cooling-levels
- Remove default-pulse-width property and stick to default hwmon policy
Changes for v3:
- Changing commit title from "hwmon: dts: Doc:" to "Documentation: dts"
- Remove unnecessary properties
- Set maximal cooling level to 230 instead of 255
---
 Documentation/devicetree/bindings/hwmon/pwm-fan.txt | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
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Patch

diff --git a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
index 610757c..d53fe0c 100644
--- a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
+++ b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
@@ -3,10 +3,30 @@  Bindings for a fan connected to the PWM lines
 Required properties:
 - compatible	: "pwm-fan"
 - pwms		: the PWM that is used to control the PWM fan
+- cooling-levels      : PWM duty cycle values in a range from 0 to 255
+			which correspond to thermal cooling states
+
+Thorough description of the following bindings:
+		cooling-min-state = <0>;
+		cooling-max-state = <3>;
+		#cooling-cells = <2>;
+		thermal-zone {
+			cpu_thermal: cpu-thermal {
+			cooling-maps {
+				map0 {
+				     trip = <&cpu_alert1>;
+				     cooling-device = <&fan0 0 1>;
+				};
+			};
+		};
+
+for PWM FAN used as cooling device can be found at:
+./Documentation/devicetree/bindings/thermal/thermal.txt
 
 Example:
 	pwm-fan {
 		compatible = "pwm-fan";
 		status = "okay";
 		pwms = <&pwm 0 10000 0>;
+		cooling-levels = <0 102 170 230>;
 	};