linux/Documentation/devicetree/bindings/clock/amlogic,meson8b-clkc.txt
Martin Blumenstingl 6c76307716 dt-bindings: clock: meson8b: use the registers from the HHI syscon
The clock controller on Meson8/Meson8m2 and Meson8b is part of a
register region called "HHI". This register area contains more
functionality than just a clock controller:
- the clock controller
- some reset controller bits
- temperature sensor calibration coefficient (only on Meson8b and
  Meson8m2 - one one out of five TSC bits is stored in the HHI
  registers)
- HDMI controller

The HHI register area may be accessed concurrently. Allow this by using
a "system controller" as parent node.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181028120859.5735-2-martin.blumenstingl@googlemail.com
2018-11-23 15:11:56 +01:00

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* Amlogic Meson8, Meson8b and Meson8m2 Clock and Reset Unit
The Amlogic Meson8 / Meson8b / Meson8m2 clock controller generates and
supplies clock to various controllers within the SoC.
Required Properties:
- compatible: must be one of:
- "amlogic,meson8-clkc" for Meson8 (S802) SoCs
- "amlogic,meson8b-clkc" for Meson8 (S805) SoCs
- "amlogic,meson8m2-clkc" for Meson8m2 (S812) SoCs
- #clock-cells: should be 1.
- #reset-cells: should be 1.
Parent node should have the following properties :
- compatible: "amlogic,meson-hhi-sysctrl", "simple-mfd", "syscon"
- reg: base address and size of the HHI system control register space.
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 the dt-bindings/clock/meson8b-clkc.h header and can be
used in device tree sources.
Similarly a preprocessor macro for each reset line is defined in
dt-bindings/reset/amlogic,meson8b-clkc-reset.h (which can be used from the
device tree sources).
Example: Clock controller node:
clkc: clock-controller {
compatible = "amlogic,meson8b-clkc";
#clock-cells = <1>;
#reset-cells = <1>;
};
Example: UART controller node that consumes the clock generated by the clock
controller:
uart_AO: serial@c81004c0 {
compatible = "amlogic,meson-uart";
reg = <0xc81004c0 0x14>;
interrupts = <0 90 1>;
clocks = <&clkc CLKID_CLK81>;
};