On Sat, Apr 17, 2021 at 07:51:27AM -0500, Nishanth Menon wrote:

On 16:55-20210416, Stephen Boyd wrote:

quoted

Quoting Nishanth Menon (2021-04-15 23:37:19)

quoted

diff --git a/Documentation/devicetree/bindings/clock/ti,sci-clk.yaml b/Documentation/devicetree/bindings/clock/ti,sci-clk.yaml
new file mode 100644
index 000000000000..72633651f0c7
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/ti,sci-clk.yaml

@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/ti,sci-clk.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI-SCI clock controller node bindings
+
+maintainers:
+  - Nishanth Menon <nm@ti.com>
+
+allOf:
+  - $ref: /schemas/clock/clock.yaml#

Is this needed?

No. It is already applied to every node.

https://github.com/devicetree-org/dt-schema/blob/master/schemas/clock/clock.yaml
This standardizes provider properties like '#clock-cells' etc, allowing
you to add more stricter checks or controls in the future if necessary.

while:

https://github.com/devicetree-org/dt-schema/blob/master/meta-schemas/clocks.yaml
is more a consumer node description.

No, the meta-schema is what checks the schemas just as the schemas check 
dts files.

Should I have picked a different yaml as base for a standard clock-controller
base?

quoted

quoted

+
+description: |
+  Some TI SoCs contain a system controller (like the Power Management Micro
+  Controller (PMMC) on Keystone 66AK2G SoC) that are responsible for controlling
+  the state of the various hardware modules present on the SoC. Communication
+  between the host processor running an OS and the system controller happens
+  through a protocol called TI System Control Interface (TI-SCI protocol).
+
+  This clock controller node uses the TI SCI protocol to perform various clock
+  management of various hardware modules (devices) present on the SoC. This
+  node must be a child node of the associated TI-SCI system controller node.
+
+properties:
+  $nodename:
+    pattern: "^clock-controller$"

Is this nodename pattern check required?

I'd like the definition on rails and not subject to interpretation, and
restrict the kind of subnodes under TISCI controller node.

If this schema was standalone and not defined as part of another, then 
yes it would be required. In your case, you can enforce the node name 
from the parent schema. For consistency though, it would be better to 
just always require $nodename. 

Actually, this schema will be applied twice. On it's own matching the 
compatible string and by the parent schema. You can prevent that with 
'select: false'. I don't mind the double validation as if the parent 
node had a compatible typo you'd get zero validation.

quoted

quoted

+
+  compatible:
+    const: ti,k2g-sci-clk

I thought most things keyed off the compatible string.

Yes, they are. I am not sure I understand your question here. Did you
mean to indicate that having $nodename and compatible both are
redundant?

Redundancy was'nt the intent of this schema definition, rather, I'd like
to make sure that it is not upto interpretation or debate as to what the
node name should be: I believe clock-controller is the correct nodename
(without @0x... since this does'nt use reg property) instead of using
clocks, tisci-clock as the node names.


Do you suggest something  different?

-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D)/Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D