Power-domains need to express their active states in DT and what's
better than OPP table for that.
This patch allows power-domains to reuse OPP tables to express their
active states. The "opp-hz" property isn't a required property anymore
as power-domains may not always use them.
Add a new property "domain-performance-state", which will contain
positive integer values to represent performance levels of the
power-domains as described in this patch.
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
Documentation/devicetree/bindings/opp/opp.txt | 73 ++++++++++++++++++++++++++-
1 file changed, 71 insertions(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt
index 63725498bd20..d0b95c9e1011 100644
--- a/Documentation/devicetree/bindings/opp/opp.txt
+++ b/Documentation/devicetree/bindings/opp/opp.txt
@@ -76,10 +76,9 @@ This describes the OPPs belonging to a device. This node can have following
This defines voltage-current-frequency combinations along with other related
properties.
-Required properties:
+Optional properties:
- opp-hz: Frequency in Hz, expressed as a 64-bit big-endian integer.
-Optional properties:
- opp-microvolt: voltage in micro Volts.
A single regulator's voltage is specified with an array of size one or three.
@@ -154,6 +153,19 @@ properties.
- status: Marks the node enabled/disabled.
+- domain-performance-state: A positive integer value representing the minimum
+ power-domain performance level required by the device for the OPP node. The
+ integer value '0' represents the lowest performance level and the higher
+ values represent higher performance levels. When present in the OPP table of a
+ power-domain, it represents the performance level of the domain. When present
+ in the OPP table of a normal device, it represents the performance level of
+ the parent power-domain. The OPP table can contain the
+ "domain-performance-state" property, only if the device node contains the
+ "power-domains" or "#power-domain-cells" property. The OPP nodes aren't
+ allowed to contain the "domain-performance-state" property partially, i.e.
+ Either all OPP nodes in the OPP table have the "domain-performance-state"
+ property or none of them have it.
+
Example 1: Single cluster Dual-core ARM cortex A9, switch DVFS states together.
/ {
@@ -528,3 +540,60 @@ Example 5: opp-supported-hw
};
};
};
+
+Example 7: domain-Performance-state:
+(example: For 1GHz require domain state 1 and for 1.1 & 1.2 GHz require state 2)
+
+/ {
+ domain_opp_table: opp_table0 {
+ compatible = "operating-points-v2";
+
+ opp@1 {
+ domain-performance-state = <1>;
+ opp-microvolt = <975000 970000 985000>;
+ };
+ opp@2 {
+ domain-performance-state = <2>;
+ opp-microvolt = <1075000 1000000 1085000>;
+ };
+ };
+
+ foo_domain: power-controller@12340000 {
+ compatible = "foo,power-controller";
+ reg = <0x12340000 0x1000>;
+ #power-domain-cells = <0>;
+ operating-points-v2 = <&domain_opp_table>;
+ }
+
+ cpu0_opp_table: opp_table1 {
+ compatible = "operating-points-v2";
+ opp-shared;
+
+ opp@1000000000 {
+ opp-hz = /bits/ 64 <1000000000>;
+ domain-performance-state = <1>;
+ };
+ opp@1100000000 {
+ opp-hz = /bits/ 64 <1100000000>;
+ domain-performance-state = <2>;
+ };
+ opp@1200000000 {
+ opp-hz = /bits/ 64 <1200000000>;
+ domain-performance-state = <2>;
+ };
+ };
+
+ cpus {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ cpu@0 {
+ compatible = "arm,cortex-a9";
+ reg = <0>;
+ clocks = <&clk_controller 0>;
+ clock-names = "cpu";
+ operating-points-v2 = <&cpu0_opp_table>;
+ power-domains = <&foo_domain>;
+ };
+ };
+};
--
2.12.0.432.g71c3a4f4ba37
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