[PATCH 01/13] dt-bindings: clock: Add Amlogic A9 standardized model clock control units

Chuan Liu via B4 Relay
2026-02-09T05:49:25Z

From: Chuan Liu <chuan.liu@amlogic.com>

Add dt-binding documentation for standardized model clock control units
in A9 SoC family.

Signed-off-by: Chuan Liu <chuan.liu@amlogic.com>
---
.../bindings/clock/amlogic,a9-model-ccu.yaml | 435 +++++++++++++++++++++
1 file changed, 435 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/amlogic,a9-model-ccu.yaml b/Documentation/devicetree/bindings/clock/amlogic,a9-model-ccu.yaml
new file mode 100644
index 000000000000..56c5cbe1b246
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/amlogic,a9-model-ccu.yaml
@@ -0,0 +1,435 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2026 Amlogic, Inc. All rights reserved
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/amlogic,a9-model-ccu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Amlogic A9 Family Standardized Model Clock Control Unit
+
+maintainers:
+ - Chuan Liu <chuan.liu@amlogic.com>
+
+description:
+ The clock tree within the A9 is composed of numerous instances of these
+ standardized model CCU (Clock Control Units).
+
+properties:
+ compatible:
+ oneOf:
+ - items:
+ - const: amlogic,a9-composite-ccu
+ description: Supports clock source selection, frequency division, and
+ clock gating.
+ - items:
+ - const: amlogic,a9-composite-ccu-mult
+ description: Some modules have multiple input clocks and contain
+ multiple composite-ccus internally.
+ - items:
+ - const: amlogic,a9-noglitch-ccu
+ description: Provides the same functionality as composite-ccu but
+ includes glitch suppression during frequency transitions.
+ - items:
+ - const: amlogic,a9-noglitch-ccu-mult
+ description: Some modules have multiple input clocks and contain
+ multiple noglitch-ccus internally.
+ - items:
+ - const: amlogic,a9-sysbus-ccu
+ description: Consists of multiple gating arrays, commonly used for
+ Amlogic's sys_clk and axi_clk.
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ minItems: 1
+ maxItems: 16
+
+ clock-names:
+ minItems: 1
+ maxItems: 16
+
+ clock-output-names:
+ minItems: 1
+ # The sysbus-ccu of A9 supports up to 128 gates
+ maxItems: 128
+
+ '#clock-cells':
+ description:
+ The clock controller of a module may contain one or more CCU(s). When a
+ clock controller has multiple CCUs, an index is required to specify a
+ particular CCU within the clock controller.
+ oneOf:
+ - const: 0
+ description: Single clock output, no specifier needed
+ - const: 1
+ description: Multiple clocks, index selects specific output
+
+ amlogic,clock-max-frequency:
+ description: |
+ Each clock's maximum output frequency is constrained during hardware
+ design to ensure proper timing requirements for the clock network. If the
+ clock frequency configured exceeds this design limit, it can lead to
+ abnormal behavior in modules relying on that clock and may even cause
+ cross-talk that affects other modules.
+
+ In the driver, this property is parsed, and interface functions from the
+ CCF are called to enforce the clock's maximum frequency, preventing
+ potential issues caused by excessive clock frequency configurations.
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+
+ amlogic,reg-layout:
+ description:
+ These standardized model CCUs require register configuration for their
+ clock functions. This property node describes the register layout
+ parameters for each model's CCU.
+ $ref: /schemas/types.yaml#/definitions/uint32-matrix
+
+allOf:
+ - if:
+ properties:
+ compatible:
+ anyOf:
+ - contains:
+ const: amlogic,a9-composite-ccu
+ - contains:
+ const: amlogic,a9-noglitch-ccu
+ then:
+ properties:
+ '#clock-cells':
+ const: 0
+ clock-output-names:
+ minItems: 1
+ maxItems: 1
+ else:
+ properties:
+ '#clock-cells':
+ const: 1
+ clock-output-names:
+ minItems: 2
+
+ - if:
+ properties:
+ compatible:
+ contains:
+ const: amlogic,a9-composite-ccu
+ then:
+ properties:
+ clocks:
+ minItems: 1
+ items:
+ - description: input clock source 0
+ - description: input clock source 1 (optional)
+ - description: input clock source 2 (optional)
+ - description: input clock source 3 (optional)
+ - description: input clock source 4 (optional)
+ - description: input clock source 5 (optional)
+ - description: input clock source 6 (optional)
+ - description: input clock source 7 (optional)
+ clock-names:
+ minItems: 1
+ items:
+ - const: clkin0
+ - const: clkin1
+ - const: clkin2
+ - const: clkin3
+ - const: clkin4
+ - const: clkin5
+ - const: clkin6
+ - const: clkin7
+ amlogic,reg-layout:
+ description: |
+ composite-ccu contains three register layout parameters:
+ * register offset
+ * bit offset
+ * divider effective bit width
+ required:
+ - amlogic,reg-layout
+ - clock-names
+
+ - if:
+ properties:
+ compatible:
+ contains:
+ const: amlogic,a9-composite-ccu-mult
+ then:
+ properties:
+ clocks:
+ description:
+ Some clock controllers contain two composite-ccus (labeled
+ composite_a and composite_b). In certain controllers, composite_a
+ and composite_b share a common clock source, while in others they
+ have independent clock sources.
+ minItems: 1
+ items:
+ - description: composite_a/b's input clock source 0
+ - description: composite_a/b's input clock source 1 (optional)
+ - description: composite_a/b's input clock source 2 (optional)
+ - description: composite_a/b's input clock source 3 (optional)
+ - description: composite_a/b's input clock source 4 (optional)
+ - description: composite_a/b's input clock source 5 (optional)
+ - description: composite_a/b's input clock source 6 (optional)
+ - description: composite_a/b's input clock source 7 (optional)
+ - description: composite_b's input clock source 0 (optional)
+ - description: composite_b's input clock source 1 (optional)
+ - description: composite_b's input clock source 2 (optional)
+ - description: composite_b's input clock source 3 (optional)
+ - description: composite_b's input clock source 4 (optional)
+ - description: composite_b's input clock source 5 (optional)
+ - description: composite_b's input clock source 6 (optional)
+ - description: composite_b's input clock source 7 (optional)
+ clock-names:
+ minItems: 1
+ items:
+ - const: clkin0
+ - const: clkin1
+ - const: clkin2
+ - const: clkin3
+ - const: clkin4
+ - const: clkin5
+ - const: clkin6
+ - const: clkin7
+ - const: bclkin0
+ - const: bclkin1
+ - const: bclkin2
+ - const: bclkin3
+ - const: bclkin4
+ - const: bclkin5
+ - const: bclkin6
+ - const: bclkin7
+ amlogic,reg-layout:
+ description: |
+ composite-ccu contains three register layout parameters:
+ * register offset
+ * bit offset
+ * divider effective bit width
+ required:
+ - amlogic,reg-layout
+ - clock-names
+
+ - if:
+ properties:
+ compatible:
+ contains:
+ const: amlogic,a9-noglitch-ccu
+ then:
+ properties:
+ clocks:
+ minItems: 1
+ items:
+ - description: input clock source 0
+ - description: input clock source 1 (optional)
+ - description: input clock source 2 (optional)
+ - description: input clock source 3 (optional)
+ - description: input clock source 4 (optional)
+ - description: input clock source 5 (optional)
+ - description: input clock source 6 (optional)
+ - description: input clock source 7 (optional)
+ clock-names:
+ minItems: 1
+ items:
+ - const: clkin0
+ - const: clkin1
+ - const: clkin2
+ - const: clkin3
+ - const: clkin4
+ - const: clkin5
+ - const: clkin6
+ - const: clkin7
+ required:
+ - clock-names
+
+ - if:
+ properties:
+ compatible:
+ contains:
+ const: amlogic,a9-noglitch-ccu-mult
+ then:
+ properties:
+ clocks:
+ minItems: 1
+ items:
+ - description: input clock source 0
+ - description: input clock source 1 (optional)
+ - description: input clock source 2 (optional)
+ - description: input clock source 3 (optional)
+ - description: input clock source 4 (optional)
+ - description: input clock source 5 (optional)
+ - description: input clock source 6 (optional)
+ - description: input clock source 7 (optional)
+ clock-names:
+ minItems: 1
+ items:
+ - const: clkin0
+ - const: clkin1
+ - const: clkin2
+ - const: clkin3
+ - const: clkin4
+ - const: clkin5
+ - const: clkin6
+ - const: clkin7
+ amlogic,reg-layout:
+ description: |
+ composite-ccu contains one register layout parameters:
+ * register offset
+ required:
+ - amlogic,reg-layout
+ - clock-names
+
+ - if:
+ properties:
+ compatible:
+ contains:
+ const: amlogic,a9-sysbus-ccu
+ then:
+ properties:
+ clocks:
+ maxItems: 1
+ description: input clock of sysbus-ccu
+ amlogic,reg-layout:
+ description: |
+ composite-ccu contains two register layout parameters:
+ * register offset
+ * bit offset
+ required:
+ - amlogic,reg-layout
+
+required:
+ - compatible
+ - reg
+ - clocks
+ - clock-output-names
+ - "#clock-cells"
+
+additionalProperties: false
+
+examples:
+ - |
+ clk_dummy: clock-dummy {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-frequency = <0>;
+ clock-output-names = "dummy";
+ status = "disabled";
+ };
+
+ apb {
+ #address-cells = <2>;
+ #size-cells = <2>;
+ clock-controller@350 {
+ compatible = "amlogic,a9-composite-ccu";
+ reg = <0x0 0x350 0x0 0x4>;
+ #clock-cells = <0>;
+ amlogic,clock-max-frequency = <50000000>;
+ amlogic,reg-layout = <0x0 0 7>;
+ clock-output-names = "sar_adc";
+ clocks = <&xtal_24m>,
+ <&scmi_clk 17>;
+ clock-names = "clkin0", "clkin1";
+ };
+
+ clock-controller@290 {
+ compatible = "amlogic,a9-composite-ccu-mult";
+ reg = <0x0 0x290 0x0 0x8>;
+ #clock-cells = <1>;
+ amlogic,clock-max-frequency = <250000000>,
+ <250000000>,
+ <1200000000>;
+ amlogic,reg-layout = <0x0 0 7>,
+ <0x0 16 7>,
+ <0x4 0 7>;
+ clock-output-names = "sd_emmc_a",
+ "sd_emmc_b",
+ "sd_emmc_c";
+ clocks = <&xtal_24m>,
+ <&scmi_clk 6>,
+ <&scmi_clk 10>;
+ clock-names = "clkin0",
+ "clkin1",
+ "clkin2";
+ };
+
+ clock-controller@378 {
+ compatible = "amlogic,a9-composite-ccu-mult";
+ reg = <0x0 0x378 0x0 0x4>;
+ #clock-cells = <1>;
+ amlogic,clock-max-frequency = <500000000>,
+ <667000000>;
+ amlogic,reg-layout = <0x0 0 7>,
+ <0x0 16 7>;
+ clock-output-names = "dptx_apb2",
+ "dptx_aud";
+ clocks = <&xtal_24m>,
+ <&scmi_clk 17>,
+ <&scmi_clk 12>,
+ <&scmi_clk 14>,
+ <&clk_dummy>,
+ <&clk_dummy>,
+ <&clk_dummy>,
+ <&clk_dummy>,
+ <&xtal_24m>, /* composite-ccu_b's clock source 0 */
+ <&scmi_clk 17>, /* composite-ccu_b's clock source 1 */
+ <&scmi_clk 10>, /* composite-ccu_b's clock source 2 */
+ <&scmi_clk 12>; /* composite-ccu_b's clock source 3 */
+ clock-names = "clkin0",
+ "clkin1",
+ "clkin2",
+ "clkin3",
+ "clkin4",
+ "clkin5",
+ "clkin6",
+ "clkin7",
+ "bclkin0",
+ "bclkin1",
+ "bclkin2",
+ "bclkin3";
+ };
+
+ clock-controller@420 {
+ compatible = "amlogic,a9-noglitch-ccu";
+ reg = <0x0 0x420 0x0 0x4>;
+ #clock-cells = <0>;
+ amlogic,clock-max-frequency = <800000000>;
+ clock-output-names = "dspa";
+ clocks = <&xtal_24m>,
+ <&scmi_clk 8>,
+ <&scmi_clk 10>;
+ clock-names = "clkin0",
+ "clkin1",
+ "clkin2";
+ };
+
+ clock-controller@400 {
+ compatible = "amlogic,a9-noglitch-ccu-mult";
+ reg = <0x0 0x400 0x0 0x8>;
+ #clock-cells = <1>;
+ /*
+ * If only one maximum frequency is specified, it is shared by all
+ * clocks under the current device node.
+ */
+ amlogic,clock-max-frequency = <1000000000>;
+ amlogic,reg-layout = <0x0>,
+ <0x4>;
+ clock-output-names = "mali",
+ "mali_stack";
+ clocks = <&xtal_24m>,
+ <&scmi_clk 23>,
+ <&scmi_clk 6>;
+ clock-names = "clkin0",
+ "clkin1",
+ "clkin2";
+ };
+
+ clock-sysbus@230 {
+ compatible = "amlogic,a9-sysbus-ccu";
+ reg = <0x0 0x230 0x0 0x10>;
+ #clock-cells = <1>;
+ amlogic,reg-layout = <0 0>,
+ <0 1>,
+ <0 3>;
+ clock-output-names = "sys_am_axi",
+ "sys_dos",
+ "sys_mipi_dsi";
+ clocks = <&scmi_clk 17>;
+ };
+ };

--
2.42.0