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authorSaravanan Sekar <sravanhome@gmail.com>2018-07-19 11:06:46 +0200
committerStephen Boyd <sboyd@kernel.org>2018-07-25 16:40:53 -0700
commitd0e45d686a3ef18a20d4eac6675b76d3656c4727 (patch)
tree905e5fbbf7f695aa3762e6a5dda1f4aab2e8d364 /Documentation/devicetree/bindings/clock/actions,owl-cmu.txt
parentd017c1f16a798397ebc79be57f7a5e5ea788f837 (diff)
dt-bindings: clock: Add S700 support for Actions Semi Soc's
Add clock bindings constants for action S700 Maintain common clock dt-bindings for Actions Semi SoC's S700 and S900. Signed-off-by: Parthiban Nallathambi <pn@denx.de> Signed-off-by: Saravanan Sekar <sravanhome@gmail.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
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+* Actions Semi Owl Clock Management Unit (CMU)
+
+The Actions Semi Owl Clock Management Unit generates and supplies clock
+to various controllers within the SoC. The clock binding described here is
+applicable to S900 and S700 SoC's.
+
+Required Properties:
+
+- compatible: should be one of the following,
+ "actions,s900-cmu"
+ "actions,s700-cmu"
+- reg: physical base address of the controller and length of memory mapped
+ region.
+- clocks: Reference to the parent clocks ("hosc", "losc")
+- #clock-cells: should be 1.
+
+Each clock is assigned an identifier, and client nodes can use this identifier
+to specify the clock which they consume.
+
+All available clocks are defined as preprocessor macros in corresponding
+dt-bindings/clock/actions,s900-cmu.h or actions,s700-cmu.h header and can be
+used in device tree sources.
+
+External clocks:
+
+The hosc clock used as input for the plls is generated outside the SoC. It is
+expected that it is defined using standard clock bindings as "hosc".
+
+Actions Semi S900 CMU also requires one more clock:
+ - "losc" - internal low frequency oscillator
+
+Example: Clock Management Unit node:
+
+ cmu: clock-controller@e0160000 {
+ compatible = "actions,s900-cmu";
+ reg = <0x0 0xe0160000 0x0 0x1000>;
+ clocks = <&hosc>, <&losc>;
+ #clock-cells = <1>;
+ };
+
+Example: UART controller node that consumes clock generated by the clock
+management unit:
+
+ uart: serial@e012a000 {
+ compatible = "actions,s900-uart", "actions,owl-uart";
+ reg = <0x0 0xe012a000 0x0 0x2000>;
+ interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&cmu CLK_UART5>;
+ };