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[PATCH v2 1/3] dt-bindings: chrome: Add Cros EC UCSI driver

Jameson Thies posted 3 patches 4 months, 1 week ago
There is a newer version of this series
[PATCH v2 1/3] dt-bindings: chrome: Add Cros EC UCSI driver
Posted by Jameson Thies 4 months, 1 week ago 
Chrome OS devices with PDCs allow the host to read port status and
control port behavior with UCSI commands sent to the embedded controller
(EC). Add documentation for cros-ec-ucsi node which loads the Chrome OS
UCSI driver.

Signed-off-by: Jameson Thies <jthies@google.com>
---
 .../bindings/chrome/google,cros-ec-ucsi.yaml  | 71 +++++++++++++++++++
 .../bindings/mfd/google,cros-ec.yaml          |  4 +-
 2 files changed, 74 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml

diff --git a/Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml b/Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml
new file mode 100644
index 000000000000..2121776e3ff0
--- /dev/null
+++ b/Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/chrome/google,cros-ec-ucsi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Google Chrome OS EC(Embedded Controller) UCSI driver.
+
+maintainers:
+  - Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
+  - Andrei Kuchynski <akuchynski@chromium.org>
+  - Benson Leung <bleung@chromium.org>
+  - Jameson Thies <jthies@google.com>
+  - Łukasz Bartosik <ukaszb@chromium.org>
+
+description:
+  Chrome OS devices with PDC-based USB-C ports expose a UCSI interface
+  from the Embedded Controller (EC) which allows the host to request
+  port state and control limited port behavior (DR/PR swap). This node
+  allows the host UCSI driver to send and receive UCSI commands to a
+  Chrome OS EC. The node for this device should be under a cros-ec node
+  like google,cros-ec-spi.
+
+properties:
+  compatible:
+    const: google,cros-ec-ucsi
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+patternProperties:
+  '^connector@[0-9a-f]+$':
+    $ref: /schemas/connector/usb-connector.yaml#
+    required:
+      - reg
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |+
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      cros_ec: ec@0 {
+        compatible = "google,cros-ec-spi";
+        reg = <0>;
+        interrupts = <35 0>;
+
+        typec {
+          compatible = "google,cros-ec-ucsi";
+
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          connector@0 {
+            compatible = "usb-c-connector";
+            reg = <0>;
+            power-role = "dual";
+            data-role = "dual";
+            try-power-role = "source";
+          };
+        };
+      };
+    };
diff --git a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
index 50f457090066..646bc81c526f 100644
--- a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
+++ b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
@@ -99,7 +99,9 @@ properties:
   gpio-controller: true
 
   typec:
-    $ref: /schemas/chrome/google,cros-ec-typec.yaml#
+    oneOf:
+      - $ref: /schemas/chrome/google,cros-ec-typec.yaml#
+      - $ref: /schemas/chrome/google,cros-ec-ucsi.yaml#
 
   ec-pwm:
     $ref: /schemas/pwm/google,cros-ec-pwm.yaml#
-- 
2.51.0.618.g983fd99d29-goog
Re: [PATCH v2 1/3] dt-bindings: chrome: Add Cros EC UCSI driver
Posted by Rob Herring 4 months ago 
On Wed, Oct 01, 2025 at 07:33:41PM +0000, Jameson Thies wrote:
> Chrome OS devices with PDCs allow the host to read port status and
> control port behavior with UCSI commands sent to the embedded controller
> (EC). Add documentation for cros-ec-ucsi node which loads the Chrome OS
> UCSI driver.

What's PDC? What's UCSI?

> 
> Signed-off-by: Jameson Thies <jthies@google.com>
> ---
>  .../bindings/chrome/google,cros-ec-ucsi.yaml  | 71 +++++++++++++++++++
>  .../bindings/mfd/google,cros-ec.yaml          |  4 +-
>  2 files changed, 74 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml b/Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml
> new file mode 100644
> index 000000000000..2121776e3ff0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml
> @@ -0,0 +1,71 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/chrome/google,cros-ec-ucsi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Google Chrome OS EC(Embedded Controller) UCSI driver.
> +
> +maintainers:
> +  - Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> +  - Andrei Kuchynski <akuchynski@chromium.org>
> +  - Benson Leung <bleung@chromium.org>
> +  - Jameson Thies <jthies@google.com>
> +  - Łukasz Bartosik <ukaszb@chromium.org>
> +
> +description:
> +  Chrome OS devices with PDC-based USB-C ports expose a UCSI interface
> +  from the Embedded Controller (EC) which allows the host to request
> +  port state and control limited port behavior (DR/PR swap). This node
> +  allows the host UCSI driver to send and receive UCSI commands to a
> +  Chrome OS EC. The node for this device should be under a cros-ec node
> +  like google,cros-ec-spi.
> +
> +properties:
> +  compatible:
> +    const: google,cros-ec-ucsi
> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +patternProperties:
> +  '^connector@[0-9a-f]+$':
> +    $ref: /schemas/connector/usb-connector.yaml#
> +    required:
> +      - reg

This is the exact same binding as google,cros-ec-typec.yaml. Why are you 
duplicating the whole thing rather than just adding a new compatible 
string?

Rob
Re: [PATCH v2 1/3] dt-bindings: chrome: Add Cros EC UCSI driver
Posted by Jameson Thies 4 months ago 
> What's PDC? What's UCSI?

PDCs are "Power Delivery Controllers". It refers to an IC which
manages PD communication for a USB-C port. UCSI stands for "USB Type-C
Connector System Software Interface". It is a specification maintained
by the USB-IF which defines a standardized interface for communicating
with PDCs. I'll update the description in the v3 series to provide the
full name for both of these terms.

> This is the exact same binding as google,cros-ec-typec.yaml. Why are you
> duplicating the whole thing rather than just adding a new compatible
> string?

I separated these bindings because they are associated with separate
mutually exclusive drivers. But, I'm fine with adding this as a
compatibility string in google,cros-ec-typec.yaml and will make that
change in the v3 series.
Re: [PATCH v2 1/3] dt-bindings: chrome: Add Cros EC UCSI driver
Posted by Benson Leung 4 months ago 
On Wed, Oct 01, 2025 at 07:33:41PM +0000, Jameson Thies wrote:
> Chrome OS devices with PDCs allow the host to read port status and
> control port behavior with UCSI commands sent to the embedded controller
> (EC). Add documentation for cros-ec-ucsi node which loads the Chrome OS
> UCSI driver.
> 
> Signed-off-by: Jameson Thies <jthies@google.com>

Reviewed-by: Benson Leung <bleung@chromium.org>


> ---
>  .../bindings/chrome/google,cros-ec-ucsi.yaml  | 71 +++++++++++++++++++
>  .../bindings/mfd/google,cros-ec.yaml          |  4 +-
>  2 files changed, 74 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml b/Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml
> new file mode 100644
> index 000000000000..2121776e3ff0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/chrome/google,cros-ec-ucsi.yaml
> @@ -0,0 +1,71 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/chrome/google,cros-ec-ucsi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Google Chrome OS EC(Embedded Controller) UCSI driver.
> +
> +maintainers:
> +  - Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> +  - Andrei Kuchynski <akuchynski@chromium.org>
> +  - Benson Leung <bleung@chromium.org>
> +  - Jameson Thies <jthies@google.com>
> +  - Łukasz Bartosik <ukaszb@chromium.org>
> +
> +description:
> +  Chrome OS devices with PDC-based USB-C ports expose a UCSI interface
> +  from the Embedded Controller (EC) which allows the host to request
> +  port state and control limited port behavior (DR/PR swap). This node
> +  allows the host UCSI driver to send and receive UCSI commands to a
> +  Chrome OS EC. The node for this device should be under a cros-ec node
> +  like google,cros-ec-spi.
> +
> +properties:
> +  compatible:
> +    const: google,cros-ec-ucsi
> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +patternProperties:
> +  '^connector@[0-9a-f]+$':
> +    $ref: /schemas/connector/usb-connector.yaml#
> +    required:
> +      - reg
> +
> +required:
> +  - compatible
> +
> +additionalProperties: false
> +
> +examples:
> +  - |+
> +    spi {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      cros_ec: ec@0 {
> +        compatible = "google,cros-ec-spi";
> +        reg = <0>;
> +        interrupts = <35 0>;
> +
> +        typec {
> +          compatible = "google,cros-ec-ucsi";
> +
> +          #address-cells = <1>;
> +          #size-cells = <0>;
> +
> +          connector@0 {
> +            compatible = "usb-c-connector";
> +            reg = <0>;
> +            power-role = "dual";
> +            data-role = "dual";
> +            try-power-role = "source";
> +          };
> +        };
> +      };
> +    };
> diff --git a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
> index 50f457090066..646bc81c526f 100644
> --- a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
> +++ b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
> @@ -99,7 +99,9 @@ properties:
>    gpio-controller: true
>  
>    typec:
> -    $ref: /schemas/chrome/google,cros-ec-typec.yaml#
> +    oneOf:
> +      - $ref: /schemas/chrome/google,cros-ec-typec.yaml#
> +      - $ref: /schemas/chrome/google,cros-ec-ucsi.yaml#
>  
>    ec-pwm:
>      $ref: /schemas/pwm/google,cros-ec-pwm.yaml#
> -- 
> 2.51.0.618.g983fd99d29-goog
>

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