Re: [PATCH v3 1/4] dt-bindings: Add cros-ec Type C port driver

Hi Rob,

Thanks for reviewing the patch. Please see inline.

On Thu, Feb 27, 2020 at 05:15:47PM -0600, Rob Herring wrote:

On Thu, Feb 27, 2020 at 05:12:16PM +0200, Heikki Krogerus wrote:

quoted

Hi,

On Wed, Feb 19, 2020 at 04:30:55PM -0800, Prashant Malani wrote:

quoted

Some Chrome OS devices with Embedded Controllers (EC) can read and
modify Type C port state.

Add an entry in the DT Bindings documentation that lists out the logical
device and describes the relevant port information, to be used by the
corresponding driver.

Signed-off-by: Prashant Malani <redacted>
---

Changes in v3:
- Fixed license identifier.
- Renamed "port" to "connector".
- Made "connector" be a "usb-c-connector" compatible property.
- Updated port-number description to explain min and max values,
  and removed $ref which was causing dt_binding_check errors.
- Fixed power-role, data-role and try-power-role details to make
  dt_binding_check pass.
- Fixed example to include parent EC SPI DT Node.

Changes in v2:
- No changes. Patch first introduced in v2 of series.

 .../bindings/chrome/google,cros-ec-typec.yaml | 86 +++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/chrome/google,cros-ec-typec.yaml

diff --git a/Documentation/devicetree/bindings/chrome/google,cros-ec-typec.yaml b/Documentation/devicetree/bindings/chrome/google,cros-ec-typec.yaml
new file mode 100644
index 00000000000000..97fd982612f120
--- /dev/null
+++ b/Documentation/devicetree/bindings/chrome/google,cros-ec-typec.yaml

@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/chrome/google,cros-ec-typec.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Google Chrome OS EC(Embedded Controller) Type C port driver.
+
+maintainers:
+  - Benson Leung <bleung@chromium.org>
+  - Prashant Malani <pmalani@chromium.org>
+
+description:
+  Chrome OS devices have an Embedded Controller(EC) which has access to
+  Type C port state. This node is intended to allow the host to read and
+  control the Type C ports. The node for this device should be under a
+  cros-ec node like google,cros-ec-spi.
+
+properties:
+  compatible:
+    const: google,cros-ec-typec
+
+  connector:
+    description: A node that represents a physical Type C connector port
+      on the device.
+    type: object
+    properties:
+      compatible:
+        const: usb-c-connector
+      port-number:
+        description: The number used by the Chrome OS EC to identify
+          this type C port. Valid values are 0 - (EC_USB_PD_MAX_PORTS - 1).
+      power-role:
+        description: Determines the power role that the Type C port will
+          adopt.
+        maxItems: 1
+        contains:
+          enum:
+            - sink
+            - source
+            - dual
+      data-role:
+        description: Determines the data role that the Type C port will
+          adopt.
+        maxItems: 1
+        contains:
+          enum:
+            - host
+            - device
+            - dual
+      try-power-role:
+        description: Determines the preferred power role of the Type C port.
+        maxItems: 1
+        contains:
+          enum:
+            - sink
+            - source
+            - dual
+
+    required:
+      - port-number
+      - power-role
+      - data-role
+      - try-power-role

Do you really need to redefine those?

No.

quoted

I think you just need to mention that there is a required sub-node
"connector", and the place where it's described. So something
like this:

        Required sub-node:
        - connector : The "usb-c-connector". The bindings of the
          connector node are specified in:

                Documentation/devicetree/bindings/connector/usb-connector.txt

Ideally, we'd convert this to schema first and then here just have:

I've converted this to schema here: https://lkml.org/lkml/2020/3/4/790
I've sent that patch separately from this series, since there is ongoing
discussion regarding the structure of the bindings (and use of OF graph
API) here.

connector:
  $ref: /schemas/connector/usb-connector.yaml#

quoted

Then you just need to define the Chrome OS EC specific properties, so
I guess just the "port-number".

'reg' as Stephen suggested.

Rob