Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 1 | * Amlogic Meson8, Meson8b and Meson8m2 Clock and Reset Unit |
| 2 | |
| 3 | The Amlogic Meson8 / Meson8b / Meson8m2 clock controller generates and |
| 4 | supplies clock to various controllers within the SoC. |
| 5 | |
| 6 | Required Properties: |
| 7 | |
| 8 | - compatible: must be one of: |
| 9 | - "amlogic,meson8-clkc" for Meson8 (S802) SoCs |
| 10 | - "amlogic,meson8b-clkc" for Meson8 (S805) SoCs |
| 11 | - "amlogic,meson8m2-clkc" for Meson8m2 (S812) SoCs |
| 12 | - #clock-cells: should be 1. |
| 13 | - #reset-cells: should be 1. |
| 14 | - clocks: list of clock phandles, one for each entry in clock-names |
| 15 | - clock-names: should contain the following: |
| 16 | * "xtal": the 24MHz system oscillator |
| 17 | * "ddr_pll": the DDR PLL clock |
| 18 | * "clk_32k": (if present) the 32kHz clock signal from GPIOAO_6 (CLK_32K_IN) |
| 19 | |
| 20 | Parent node should have the following properties : |
| 21 | - compatible: "amlogic,meson-hhi-sysctrl", "simple-mfd", "syscon" |
| 22 | - reg: base address and size of the HHI system control register space. |
| 23 | |
| 24 | Each clock is assigned an identifier and client nodes can use this identifier |
| 25 | to specify the clock which they consume. All available clocks are defined as |
| 26 | preprocessor macros in the dt-bindings/clock/meson8b-clkc.h header and can be |
| 27 | used in device tree sources. |
| 28 | |
| 29 | Similarly a preprocessor macro for each reset line is defined in |
| 30 | dt-bindings/reset/amlogic,meson8b-clkc-reset.h (which can be used from the |
| 31 | device tree sources). |
| 32 | |
| 33 | |
| 34 | Example: Clock controller node: |
| 35 | |
| 36 | clkc: clock-controller { |
| 37 | compatible = "amlogic,meson8b-clkc"; |
| 38 | #clock-cells = <1>; |
| 39 | #reset-cells = <1>; |
| 40 | }; |
| 41 | |
| 42 | |
| 43 | Example: UART controller node that consumes the clock generated by the clock |
| 44 | controller: |
| 45 | |
| 46 | uart_AO: serial@c81004c0 { |
| 47 | compatible = "amlogic,meson-uart"; |
| 48 | reg = <0xc81004c0 0x14>; |
| 49 | interrupts = <0 90 1>; |
| 50 | clocks = <&clkc CLKID_CLK81>; |
| 51 | }; |