dt-bindings: i2c: exynos5: Add bus clock

In new Exynos SoCs (like Exynos850) where HSI2C is implemented as a
part of USIv2 block, there are two clocks provided to HSI2C controller:
  - PCLK: bus clock (APB), provides access to register interface
  - IPCLK: operating IP-core clock; SCL is derived from this one

Both clocks have to be asserted for HSI2C to be functional in that case.

Modify bindings doc to allow specifying bus clock in addition to
already described operating clock.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Documentation/devicetree/bindings/i2c/i2c-exynos5.yaml

@@ -18,9 +18,6 @@ description: |
   define USI node in device tree file, choosing "i2c" configuration. Please see
   Documentation/devicetree/bindings/soc/samsung/exynos-usi.yaml for details.
 
-allOf:
-  - $ref: /schemas/i2c/i2c-controller.yaml#
-
 properties:
   compatible:
     oneOf:
@@ -49,11 +46,16 @@ properties:
       clock-frequency is >= 1MHz.
 
   clocks:
-    maxItems: 1
-    description: I2C operating clock
+    minItems: 1
+    items:
+      - description: I2C operating clock
+      - description: Bus clock (APB)
 
   clock-names:
-    const: hsi2c
+    minItems: 1
+    items:
+      - const: hsi2c
+      - const: hsi2c_pclk
 
 required:
   - compatible
@@ -61,6 +63,31 @@ required:
   - interrupts
   - clocks
 
+allOf:
+  - $ref: /schemas/i2c/i2c-controller.yaml#
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - samsung,exynosautov9-hsi2c
+
+    then:
+      properties:
+        clocks:
+          minItems: 2
+
+        clock-names:
+          minItems: 2
+
+      required:
+        - clock-names
+
+    else:
+      properties:
+        clocks:
+          maxItems: 1
+
 unevaluatedProperties: false
 
 examples:
@@ -84,3 +111,23 @@ examples:
             reg = <0x66>;
         };
     };
+
+  - |
+    #include <dt-bindings/clock/exynos850.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    hsi2c_2: i2c@138c0000 {
+        compatible = "samsung,exynosautov9-hsi2c";
+        reg = <0x138c0000 0xc0>;
+        interrupts = <GIC_SPI 195 IRQ_TYPE_LEVEL_HIGH>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+        clocks = <&cmu_peri CLK_GOUT_HSI2C2_IPCLK>,
+                 <&cmu_peri CLK_GOUT_HSI2C2_PCLK>;
+        clock-names = "hsi2c", "hsi2c_pclk";
+
+        pmic@66 {
+            /* compatible = "samsung,s2mps11-pmic"; */
+            reg = <0x66>;
+        };
+    };