Hi Conor,

On Thu, 27 Jul 2023 09:19:59 +0100
Conor Dooley [off-list ref] wrote:

On Wed, Jul 26, 2023 at 05:02:01PM +0200, Herve Codina wrote:

quoted

The QMC (QUICC mutichannel controller) is a controller present in some
PowerQUICC SoC such as MPC885.
The QMC HDLC uses the QMC controller to transfer HDLC data.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 .../devicetree/bindings/net/fsl,qmc-hdlc.yaml | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/fsl,qmc-hdlc.yaml

diff --git a/Documentation/devicetree/bindings/net/fsl,qmc-hdlc.yaml b/Documentation/devicetree/bindings/net/fsl,qmc-hdlc.yaml
new file mode 100644
index 000000000000..8bb6f34602d9
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/fsl,qmc-hdlc.yaml

@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/fsl,qmc-hdlc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: QMC HDLC  

"QMC HDLC" seems excessively terse.

The name was based on the fsl,qmc-audio.yaml already present upstream.
  https://elixir.bootlin.com/linux/v6.4/source/Documentation/devicetree/bindings/sound/fsl,qmc-audio.yaml

If needed, I can change to:
  title: QMC (QUICC Multichannel Controller) HDLC
Let me known if it is better to you.

quoted

+
+maintainers:
+  - Herve Codina [off-list ref]
+
+description: |
+  The QMC HDLC uses a QMC (QUICC Multichannel Controller) channel to transfer
+  HDLC data.
+
+properties:
+  compatible:
+    const: fsl,qmc-hdlc
+
+  fsl,qmc-chan:  

Perhaps I am just showing my lack of knowledge in this area, but what is
fsl specific about wanting a reference to the channel of a "QMC"?
Is this something that hardware from other manufacturers would not also
want to do?

The QMC and the QMC channel are something specific to the SoC. This IP is only
available on some Freescale/NXP SoCs.

When I upstreamed the 'fsl,qmc-audio.yaml', I first used a generic name for this
property and Kristoff asked to change to a vendor prefixed name.
  https://lore.kernel.org/linux-kernel/1dfade07-f8c4-2e16-00dc-c7d183708259@linaro.org/ (local)

Based on this, as the property 'fsl,qmc-chan' has the exact same meaning in
fsl,qmc-audio.yaml and fsl,qmc-hdlc.yaml, I use the same name.

Best regards,
Hervé

quoted

+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      - items:
+          - description: phandle to QMC node
+          - description: Channel number
+    description:
+      Should be a phandle/number pair. The phandle to QMC node and the QMC
+      channel to use.
+
+required:
+  - compatible
+  - fsl,qmc-chan
+
+additionalProperties: false
+
+examples:
+  - |
+    hdlc {
+        compatible = "fsl,qmc-hdlc";
+        fsl,qmc-chan = <&qmc 16>;
+    };
-- 
2.41.0