[PATCH v4 1/3] dt-bindings: usb: usb251xb: support usage case without I2C control

[Jisheng Zhang <jszhang@kernel.org>]

Currently, the usb251xb assumes i2c control, but from HW point of
view, the hub supports usage case without any i2c control, I.E we
only want the gpio controls, for example the following dt node:

usb-hub {
	compatible = "microchip,usb2512b";
	reset-gpios = <&porta 8 GPIO_ACTIVE_LOW>;
};

Modify the dt-binding of usb2512b to support this usage case, and add
the usage example to the examples section.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 Documentation/devicetree/bindings/usb/usb251xb.yaml | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/usb/usb251xb.yaml b/Documentation/devicetree/bindings/usb/usb251xb.yaml
index ac5b99710332..0329a6aaaa92 100644
--- a/Documentation/devicetree/bindings/usb/usb251xb.yaml
+++ b/Documentation/devicetree/bindings/usb/usb251xb.yaml
@@ -240,7 +240,6 @@ additionalProperties: false
 
 required:
   - compatible
-  - reg
 
 examples:
   - |
@@ -269,3 +268,11 @@ examples:
         swap-dx-lanes = <1 2>;
       };
     };
+
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    usb-hub {
+      /* I2C is not connected */
+      compatible = "microchip,usb2512b";
+      reset-gpios = <&porta 8 GPIO_ACTIVE_LOW>;
+    };
-- 
2.50.0