Documentation: devicetree: add PPMU events description

[linux-2.6-microblaze.git] / Documentation / devicetree / bindings / devfreq / event / exynos-ppmu.txt

diff --git a/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt b/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
index 3e36c1d..fb46b49 100644 (file)
--- a/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
+++ b/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
@@ -10,14 +10,23 @@ The Exynos PPMU driver uses the devfreq-event class to provide event data
 to various devfreq devices. The devfreq devices would use the event data when
 derterming the current state of each IP.
 
-Required properties:
+Required properties for PPMU device:
 - compatible: Should be "samsung,exynos-ppmu" or "samsung,exynos-ppmu-v2.
 - reg: physical base address of each PPMU and length of memory mapped region.
 
-Optional properties:
+Optional properties for PPMU device:
 - clock-names : the name of clock used by the PPMU, "ppmu"
 - clocks : phandles for clock specified in "clock-names" property
 
+Required properties for 'events' child node of PPMU device:
+- event-name : the unique event name among PPMU device
+Optional properties for 'events' child node of PPMU device:
+- event-data-type : Define the type of data which shell be counted
+by the counter. You can check include/dt-bindings/pmu/exynos_ppmu.h for
+all possible type, i.e. count read requests, count write data in bytes,
+etc. This field is optional and when it is missing, the driver code
+will use default data type.
+
 Example1 : PPMUv1 nodes in exynos3250.dtsi are listed below.
 
                ppmu_dmc0: ppmu_dmc0@106a0000 {
@@ -145,3 +154,16 @@ Example3 : PPMUv2 nodes in exynos5433.dtsi are listed below.
                        reg = <0x104d0000 0x2000>;
                        status = "disabled";
                };
+
+Example4 : 'event-data-type' in exynos4412-ppmu-common.dtsi are listed below.
+
+       &ppmu_dmc0 {
+               status = "okay";
+               events {
+                       ppmu_dmc0_3: ppmu-event3-dmc0 {
+                       event-name = "ppmu-event3-dmc0";
+                       event-data-type = <(PPMU_RO_DATA_CNT |
+                                       PPMU_WO_DATA_CNT)>;
+                       };
+               };
+       };