Add device-tree binding that describes CPU frequency-scaling hardware
found on NVIDIA Tegra20/30 SoCs.
Signed-off-by: Dmitry Osipenko <dig...@gmail.com>
---
.../cpufreq/nvidia,tegra20-cpufreq.txt | 56 +++++++++++++++++++
1 file changed, 56 insertions(+)
create mode 100644
Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt
diff --git
a/Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt
b/Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt
new file mode 100644
index 000000000000..daeca6ae6b76
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt
@@ -0,0 +1,56 @@
+Binding for NVIDIA Tegra20 CPUFreq
+==================================
+
+Required properties:
+- clocks: Must contain an entry for the CPU clock.
+ See ../clocks/clock-bindings.txt for details.
+- operating-points-v2: See ../bindings/opp/opp.txt for details.
+- #cooling-cells: Should be 2. See ../thermal/thermal.txt for details.
+
+For each opp entry in 'operating-points-v2' table:
+- opp-supported-hw: Two bitfields indicating:
+ On Tegra20:
+ 1. CPU process ID mask
+ 2. SoC speedo ID mask
+
+ On Tegra30:
+ 1. CPU process ID mask
+ 2. CPU speedo ID mask
+
+ A bitwise AND is performed against these values and if any bit
+ matches, the OPP gets enabled.
+
+- opp-microvolt: CPU voltage triplet.
+
+Optional properties:
+- cpu-supply: Phandle to the CPU power supply.
+
+Example:
+ regulators {
+ cpu_reg: regulator0 {
+ regulator-name = "vdd_cpu";
+ };
+ };
+
+ cpu0_opp_table: opp_table0 {
+ compatible = "operating-points-v2";
+
+ opp@456000000 {
+ clock-latency-ns = <125000>;
+ opp-microvolt = <825000 825000 1125000>;
+ opp-supported-hw = <0x03 0x0001>;
+ opp-hz = /bits/ 64 <456000000>;
+ };
+
+ ...
+ };
+
+ cpus {
+ cpu@0 {
+ compatible = "arm,cortex-a9";
+ clocks = <&tegra_car TEGRA20_CLK_CCLK>;
+ operating-points-v2 = <&cpu0_opp_table>;
+ cpu-supply = <&cpu_reg>;
+ #cooling-cells = <2>;
+ };
+ };
--
2.23.0
