On Mon, Nov 29, 2021 at 07:44:32PM -0600, Rob Herring wrote:

On Fri, Nov 19, 2021 at 03:38:36PM +0100, Thierry Reding wrote:

quoted

From: Thierry Reding <redacted>

Convert the NVIDIA Tegra186 (and later) BPMP I2C bindings from the
free-form text format to json-schema.

Signed-off-by: Thierry Reding <redacted>
---
Changes in v2:
- add missing additionalProperties: false

 .../bindings/i2c/nvidia,tegra186-bpmp-i2c.txt | 42 -------------------
 .../i2c/nvidia,tegra186-bpmp-i2c.yaml         | 42 +++++++++++++++++++
 2 files changed, 42 insertions(+), 42 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.txt
 create mode 100644 Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.yaml

diff --git a/Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.txt b/Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.txt
deleted file mode 100644
index ab240e10debc..000000000000
--- a/Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.txt
+++ /dev/null

@@ -1,42 +0,0 @@
-NVIDIA Tegra186 BPMP I2C controller
-
-In Tegra186, the BPMP (Boot and Power Management Processor) owns certain HW
-devices, such as the I2C controller for the power management I2C bus. Software
-running on other CPUs must perform IPC to the BPMP in order to execute
-transactions on that I2C bus. This binding describes an I2C bus that is
-accessed in such a fashion.
-
-The BPMP I2C node must be located directly inside the main BPMP node. See
-../firmware/nvidia,tegra186-bpmp.txt for details of the BPMP binding.
-
-This node represents an I2C controller. See ../i2c/i2c.txt for details of the
-core I2C binding.
-
-Required properties:
-- compatible:
-    Array of strings.
-    One of:
-    - "nvidia,tegra186-bpmp-i2c".
-- #address-cells: Address cells for I2C device address.
-    Single-cell integer.
-    Must be <1>.
-- #size-cells:
-    Single-cell integer.
-    Must be <0>.
-- nvidia,bpmp-bus-id:
-    Single-cell integer.
-    Indicates the I2C bus number this DT node represent, as defined by the
-    BPMP firmware.
-
-Example:
-
-bpmp {
-	...
-
-	i2c {
-		compatible = "nvidia,tegra186-bpmp-i2c";
-		#address-cells = <1>;
-		#size-cells = <0>;
-		nvidia,bpmp-bus-id = <5>;
-	};
-};

diff --git a/Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.yaml b/Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.yaml
new file mode 100644
index 000000000000..351e12124959
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.yaml

@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/nvidia,tegra186-bpmp-i2c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVIDIA Tegra186 (and later) BPMP I2C controller
+
+maintainers:
+  - Thierry Reding <thierry.reding@gmail.com>
+  - Jon Hunter <jonathanh@nvidia.com>
+
+description: |
+  In Tegra186 and later, the BPMP (Boot and Power Management Processor)
+  owns certain HW devices, such as the I2C controller for the power
+  management I2C bus. Software running on other CPUs must perform IPC to
+  the BPMP in order to execute transactions on that I2C bus. This
+  binding describes an I2C bus that is accessed in such a fashion.
+
+  The BPMP I2C node must be located directly inside the main BPMP node.
+  See ../firmware/nvidia,tegra186-bpmp.yaml for details of the BPMP
+  binding.
+
+  This node represents an I2C controller. See ../i2c/i2c.txt for details
+  of the core I2C binding.
+
+properties:
+  compatible:
+    const: nvidia,tegra186-bpmp-i2c
+

quoted

+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0

Covered by i2c-controller.yaml. Add a reference and then use 
unevaluatedProperties.

About that: I've recently noticed that this doesn't seem to work
properly. I'm using branch draft2020-12 from your github and my
understanding was that this should give us support for
unevaluatedProperties. And indeed, it no longer complains about
#address-cells and #size-cells if I remove them from this binding,
presumably because it gets them from i2c-controller.yaml.

However, a side-effect seems to be that now it also ignores any
properties that aren't defined anywhere. So for example if I touch
up the example in firmware/nvidia,tegra186-bpmp.yaml and add a bogus
"foo-bar = <0>;" property in the BPMP I2C node, then it'll blindly
accept that as valid.

The validation will flag if I set #address-cells = <2> in the BPMP
I2C node, so validation of the schema still seems to work, but for
some reason it won't flag any properties that haven't been specified
in the schema.

Do I misunderstand how this is supposed to work, or is there something
wrong with the current implementation of unevaluatedProperties?

Thierry