dt-bindings: clock: spacemit: Add spacemit,k1-pll

Add definition for the PLL found on SpacemiT K1 SoC, which takes the
external 24MHz oscillator as input and generates clocks in various
frequencies for the system.

Signed-off-by: Haylen Chu <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Alex Elder <[e-mail]>
Reviewed-by: Yixun Lan <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Yixun Lan <[e-mail]>

Documentation/devicetree/bindings/clock/spacemit,k1-pll.yaml

···
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/spacemit,k1-pll.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SpacemiT K1 PLL
+
+maintainers:
+  - Haylen Chu <[e-mail]>
+
+properties:
+  compatible:
+    const: spacemit,k1-pll
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    description: External 24MHz oscillator
+
+  spacemit,mpmu:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      Phandle to the "Main PMU (MPMU)" syscon. It is used to check PLL
+      lock status.
+
+  "#clock-cells":
+    const: 1
+    description:
+      See <dt-bindings/clock/spacemit,k1-syscon.h> for valid indices.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - spacemit,mpmu
+  - "#clock-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    clock-controller@d4090000 {
+        compatible = "spacemit,k1-pll";
+        reg = <0xd4090000 0x1000>;
+        clocks = <&vctcxo_24m>;
+        spacemit,mpmu = <&sysctl_mpmu>;
+        #clock-cells = <1>;
+    };

include/dt-bindings/clock/spacemit,k1-syscon.h

···
 #ifndef _DT_BINDINGS_SPACEMIT_CCU_H_
 #define _DT_BINDINGS_SPACEMIT_CCU_H_
 
+/* APBS (PLL) clocks */
+#define CLK_PLL1		0
+#define CLK_PLL2		1
+#define CLK_PLL3		2
+#define CLK_PLL1_D2		3
+#define CLK_PLL1_D3		4
+#define CLK_PLL1_D4		5
+#define CLK_PLL1_D5		6
+#define CLK_PLL1_D6		7
+#define CLK_PLL1_D7		8
+#define CLK_PLL1_D8		9
+#define CLK_PLL1_D11		10
+#define CLK_PLL1_D13		11
+#define CLK_PLL1_D23		12
+#define CLK_PLL1_D64		13
+#define CLK_PLL1_D10_AUD	14
+#define CLK_PLL1_D100_AUD	15
+#define CLK_PLL2_D1		16
+#define CLK_PLL2_D2		17
+#define CLK_PLL2_D3		18
+#define CLK_PLL2_D4		19
+#define CLK_PLL2_D5		20
+#define CLK_PLL2_D6		21
+#define CLK_PLL2_D7		22
+#define CLK_PLL2_D8		23
+#define CLK_PLL3_D1		24
+#define CLK_PLL3_D2		25
+#define CLK_PLL3_D3		26
+#define CLK_PLL3_D4		27
+#define CLK_PLL3_D5		28
+#define CLK_PLL3_D6		29
+#define CLK_PLL3_D7		30
+#define CLK_PLL3_D8		31
+#define CLK_PLL3_80		32
+#define CLK_PLL3_40		33
+#define CLK_PLL3_20		34
+
 /* MPMU clocks */
 #define CLK_PLL1_307P2		0
 #define CLK_PLL1_76P8		1