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authorDmitry Osipenko <digetx@gmail.com>2020-11-04 19:48:44 +0300
committerKrzysztof Kozlowski <krzk@kernel.org>2020-11-06 19:30:59 +0100
commit95e638e8b0b4bd0d51262bb7d01693039fc5ae48 (patch)
tree1b1cdfce7ccace7054a325c465c6ce2f50750a89
parent5e768b1fe46e6644cdbbbfa8c879c6cccb5639ba (diff)
downloadlinux-95e638e8b0b4bd0d51262bb7d01693039fc5ae48.tar.bz2
dt-bindings: memory: tegra20: emc: Document OPP table and voltage regulator
The SoC core voltage can't be changed without taking into account the clock rate of External Memory Controller. Document OPP table that will be used for dynamic voltage frequency scaling, taking into account EMC voltage requirement. Document optional core voltage regulator, which is optional because some boards may have a fixed core regulator and still frequency scaling may be desired to have. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Acked-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20201104164923.21238-9-digetx@gmail.com Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
-rw-r--r--Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt16
1 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt
index 82bc5b2ae7e5..67ac8d1297da 100644
--- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt
+++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt
@@ -14,11 +14,25 @@ Properties:
- clocks : Should contain EMC clock.
- nvidia,memory-controller : Phandle of the Memory Controller node.
- #interconnect-cells : Should be 0.
+- operating-points-v2: See ../bindings/opp/opp.txt for details.
+
+Optional properties:
+- core-supply: Phandle of voltage regulator of the SoC "core" power domain.
Child device nodes describe the memory settings for different configurations and clock rates.
Example:
+ opp_table: opp-table {
+ compatible = "operating-points-v2";
+
+ opp@36000000 {
+ opp-microvolt = <950000 950000 1300000>;
+ opp-hz = /bits/ 64 <36000000>;
+ };
+ ...
+ };
+
memory-controller@7000f400 {
#address-cells = < 1 >;
#size-cells = < 0 >;
@@ -28,6 +42,8 @@ Example:
interrupts = <0 78 0x04>;
clocks = <&tegra_car TEGRA20_CLK_EMC>;
nvidia,memory-controller = <&mc>;
+ core-supply = <&core_vdd_reg>;
+ operating-points-v2 = <&opp_table>;
}