dt-bindings: clock: Add bindings for Exynos850 CMU_APM

CMU_APM generates clocks for APM IP-core (Active Power Management). In
particular it generates RTC clocks, which are needed to enable rtc-s3c
driver on Exynos850 SoC.

Add clock indices and binding documentation for CMU_APM.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Link: https://lore.kernel.org/r/20211121232741.6967-2-semen.protsenko@linaro.org

Author: Sam Protsenko

Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml

@@ -32,6 +32,7 @@ properties:
   compatible:
     enum:
       - samsung,exynos850-cmu-top
+      - samsung,exynos850-cmu-apm
       - samsung,exynos850-cmu-core
       - samsung,exynos850-cmu-dpu
       - samsung,exynos850-cmu-hsi
@@ -68,6 +69,24 @@ allOf:
           items:
             - const: oscclk
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: samsung,exynos850-cmu-apm
+
+    then:
+      properties:
+        clocks:
+          items:
+            - description: External reference clock (26 MHz)
+            - description: CMU_APM bus clock (from CMU_TOP)
+
+        clock-names:
+          items:
+            - const: oscclk
+            - const: dout_clkcmu_apm_bus
+
   - if:
       properties:
         compatible:

include/dt-bindings/clock/exynos850.h

@@ -55,7 +55,34 @@
 #define CLK_GOUT_PERI_BUS		43
 #define CLK_GOUT_PERI_UART		44
 #define CLK_GOUT_PERI_IP		45
-#define TOP_NR_CLK			46
+#define CLK_MOUT_CLKCMU_APM_BUS		46
+#define CLK_DOUT_CLKCMU_APM_BUS		47
+#define CLK_GOUT_CLKCMU_APM_BUS		48
+#define TOP_NR_CLK			49
+
+/* CMU_APM */
+#define CLK_RCO_I3C_PMIC		1
+#define OSCCLK_RCO_APM			2
+#define CLK_RCO_APM__ALV		3
+#define CLK_DLL_DCO			4
+#define CLK_MOUT_APM_BUS_USER		5
+#define CLK_MOUT_RCO_APM_I3C_USER	6
+#define CLK_MOUT_RCO_APM_USER		7
+#define CLK_MOUT_DLL_USER		8
+#define CLK_MOUT_CLKCMU_CHUB_BUS	9
+#define CLK_MOUT_APM_BUS		10
+#define CLK_MOUT_APM_I3C		11
+#define CLK_DOUT_CLKCMU_CHUB_BUS	12
+#define CLK_DOUT_APM_BUS		13
+#define CLK_DOUT_APM_I3C		14
+#define CLK_GOUT_CLKCMU_CMGP_BUS	15
+#define CLK_GOUT_CLKCMU_CHUB_BUS	16
+#define CLK_GOUT_RTC_PCLK		17
+#define CLK_GOUT_TOP_RTC_PCLK		18
+#define CLK_GOUT_I3C_PCLK		19
+#define CLK_GOUT_I3C_SCLK		20
+#define CLK_GOUT_SPEEDY_PCLK		21
+#define APM_NR_CLK			22
 
 /* CMU_HSI */
 #define CLK_MOUT_HSI_BUS_USER		1