Add new constants for choosing the additional USIv1 configuration modes
in device tree. Those are further used in the USI driver to figure out
which value to write into SW_CONF register. Modify the current USI IP-core
bindings to include information about USIv1 and a compatible for
exynos8895.

Signed-off-by: Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>
---
 .../bindings/soc/samsung/exynos-usi.yaml      | 107 ++++++++++++------
 include/dt-bindings/soc/samsung,exynos-usi.h  |   3 +
 2 files changed, 74 insertions(+), 36 deletions(-)

diff --git a/Documentation/devicetree/bindings/soc/samsung/exynos-usi.yaml b/Documentation/devicetree/bindings/soc/samsung/exynos-usi.yaml
index cc92a06a3..d6c39c3e3 100644
--- a/Documentation/devicetree/bindings/soc/samsung/exynos-usi.yaml
+++ b/Documentation/devicetree/bindings/soc/samsung/exynos-usi.yaml
@@ -11,11 +11,21 @@ maintainers:
   - Krzysztof Kozlowski <krzk@kernel.org>
 
 description: |
-  USI IP-core provides selectable serial protocol (UART, SPI or High-Speed I2C).
-  USI shares almost all internal circuits within each protocol, so only one
-  protocol can be chosen at a time. USI is modeled as a node with zero or more
-  child nodes, each representing a serial sub-node device. The mode setting
-  selects which particular function will be used.
+  The USI IP-core provides configurable support for serial protocols, enabling
+  different serial communication modes depending on the version.
+
+  In USIv1, configurations are available to enable either one or two protocols
+  simultaneously in select combinations - High-Speed I2C0, High-Speed
+  I2C1, SPI, UART, High-Speed I2C0 and I2C1 or both High-Speed
+  I2C1 and UART.
+
+  In USIv2, only one protocol can be active at a time, either UART, SPI, or
+  High-Speed I2C.
+
+  The USI core shares internal circuits across protocols, meaning only the
+  selected configuration is active at any given time. USI is modeled as a node
+  with zero or more child nodes, each representing a serial sub-node device. The
+  mode setting selects which particular function will be used.
 
 properties:
   $nodename:
@@ -64,7 +74,7 @@ properties:
 
   samsung,mode:
     $ref: /schemas/types.yaml#/definitions/uint32
-    enum: [0, 1, 2, 3]
+    enum: [0, 1, 2, 3, 4, 5, 6]
     description:
       Selects USI function (which serial protocol to use). Refer to
       <include/dt-bindings/soc/samsung,exynos-usi.h> for valid USI mode values.
@@ -101,37 +111,62 @@ required:
   - samsung,sysreg
   - samsung,mode
 
-if:
-  properties:
-    compatible:
-      contains:
-        enum:
-          - samsung,exynos850-usi
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - google,gs101-usi
+              - samsung,exynos850-usi
+              - samsung,exynosautov9-usi
+              - samsung,exynosautov920-usi
+
+    then:
+      properties:
+        reg:
+          maxItems: 1
+
+        clocks:
+          items:
+            - description: Bus (APB) clock
+            - description: Operating clock for UART/SPI/I2C protocol
+
+        clock-names:
+          maxItems: 2
+
+        samsung,mode:
+          enum: [0, 1, 2, 3]
+
+      required:
+        - reg
+        - clocks
+        - clock-names
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - samsung,exynos8895-usi
+
+    then:
+      properties:
+        reg: false
+
+        clocks:
+          items:
+            - description: Bus (APB) clock
+            - description: Operating clock for UART/SPI protocol
+
+        clock-names:
+          maxItems: 2
+
+        samsung,clkreq-on: false
 
-then:
-  properties:
-    reg:
-      maxItems: 1
-
-    clocks:
-      items:
-        - description: Bus (APB) clock
-        - description: Operating clock for UART/SPI/I2C protocol
-
-    clock-names:
-      maxItems: 2
-
-  required:
-    - reg
-    - clocks
-    - clock-names
-
-else:
-  properties:
-    reg: false
-    clocks: false
-    clock-names: false
-    samsung,clkreq-on: false
+      required:
+        - clocks
+        - clock-names
 
 additionalProperties: false
 
diff --git a/include/dt-bindings/soc/samsung,exynos-usi.h b/include/dt-bindings/soc/samsung,exynos-usi.h
index b7c1406f3..aab28176c 100644
--- a/include/dt-bindings/soc/samsung,exynos-usi.h
+++ b/include/dt-bindings/soc/samsung,exynos-usi.h
@@ -13,5 +13,8 @@
 #define USI_MODE_UART		1
 #define USI_MODE_SPI		2
 #define USI_MODE_I2C		3
+#define USI_MODE_I2C1		4
+#define USI_MODE_I2C0_1		5
+#define USI_MODE_UART_I2C1	6
 
 #endif /* __DT_BINDINGS_SAMSUNG_EXYNOS_USI_H */
-- 
2.43.0

On Sun, Jan 05, 2025 at 06:03:44PM +0200, Ivaylo Ivanov wrote:
>    samsung,mode:
>      $ref: /schemas/types.yaml#/definitions/uint32
> -    enum: [0, 1, 2, 3]
> +    enum: [0, 1, 2, 3, 4, 5, 6]
>      description:
>        Selects USI function (which serial protocol to use). Refer to
>        <include/dt-bindings/soc/samsung,exynos-usi.h> for valid USI mode values.
> @@ -101,37 +111,62 @@ required:
>    - samsung,sysreg
>    - samsung,mode
>  
> -if:
> -  properties:
> -    compatible:
> -      contains:
> -        enum:
> -          - samsung,exynos850-usi
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - google,gs101-usi
> +              - samsung,exynos850-usi
> +              - samsung,exynosautov9-usi
> +              - samsung,exynosautov920-usi

I made mistake during last review - the binding had a confusing "else"
here, but that else was a no-op. All existing compatibles are fallbacked
to samsung,exynos850-usi, so previous code "contains: enum:
samsung,exynos850-usi" was covering everything.

You can drop other variants and keep the original samsung,exynos850-usi
only.

> +
> +    then:
> +      properties:
> +        reg:
> +          maxItems: 1
> +
> +        clocks:
> +          items:
> +            - description: Bus (APB) clock
> +            - description: Operating clock for UART/SPI/I2C protocol
> +
> +        clock-names:
> +          maxItems: 2
> +
> +        samsung,mode:
> +          enum: [0, 1, 2, 3]
> +
> +      required:
> +        - reg
> +        - clocks
> +        - clock-names
> +
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - samsung,exynos8895-usi

I don't see where this compatible is documented.

> +
> +    then:
> +      properties:
> +        reg: false
> +
> +        clocks:
> +          items:
> +            - description: Bus (APB) clock
> +            - description: Operating clock for UART/SPI protocol

Best regards,
Krzysztof

On 1/6/25 08:31, Krzysztof Kozlowski wrote:
> On Sun, Jan 05, 2025 at 06:03:44PM +0200, Ivaylo Ivanov wrote:
>>    samsung,mode:
>>      $ref: /schemas/types.yaml#/definitions/uint32
>> -    enum: [0, 1, 2, 3]
>> +    enum: [0, 1, 2, 3, 4, 5, 6]
>>      description:
>>        Selects USI function (which serial protocol to use). Refer to
>>        <include/dt-bindings/soc/samsung,exynos-usi.h> for valid USI mode values.
>> @@ -101,37 +111,62 @@ required:
>>    - samsung,sysreg
>>    - samsung,mode
>>  
>> -if:
>> -  properties:
>> -    compatible:
>> -      contains:
>> -        enum:
>> -          - samsung,exynos850-usi
>> +allOf:
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            enum:
>> +              - google,gs101-usi
>> +              - samsung,exynos850-usi
>> +              - samsung,exynosautov9-usi
>> +              - samsung,exynosautov920-usi
> I made mistake during last review - the binding had a confusing "else"
> here, but that else was a no-op. All existing compatibles are fallbacked
> to samsung,exynos850-usi, so previous code "contains: enum:
> samsung,exynos850-usi" was covering everything.
>
> You can drop other variants and keep the original samsung,exynos850-usi
> only.

Yeah I thought so too. It's fine, will fix in the next revision.

>
>> +
>> +    then:
>> +      properties:
>> +        reg:
>> +          maxItems: 1
>> +
>> +        clocks:
>> +          items:
>> +            - description: Bus (APB) clock
>> +            - description: Operating clock for UART/SPI/I2C protocol
>> +
>> +        clock-names:
>> +          maxItems: 2
>> +
>> +        samsung,mode:
>> +          enum: [0, 1, 2, 3]
>> +
>> +      required:
>> +        - reg
>> +        - clocks
>> +        - clock-names
>> +
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            enum:
>> +              - samsung,exynos8895-usi
> I don't see where this compatible is documented.

Right, ommited that. Yet dtbs_check W=1 still didn't catch that.

Thanks for the feedback!

Best regards,
Ivaylo

>
>> +
>> +    then:
>> +      properties:
>> +        reg: false
>> +
>> +        clocks:
>> +          items:
>> +            - description: Bus (APB) clock
>> +            - description: Operating clock for UART/SPI protocol
> Best regards,
> Krzysztof
>