[PATCH v3] dt-bindings: mfd: st,stmpe: fix PWM schema and drop legacy binding

[Manish Baing]

The st,stmpe-pwm binding is already covered by the MFD schema in
Documentation/devicetree/bindings/mfd/st,stmpe.yaml. However, the
PWM subnode was missing a 'required' properties block. This allowed
Device Tree nodes to pass validation even if the 'compatible'
string was omitted. This omission could lead to probe failures
at runtime.

Fix the schema by adding the missing 'required' block and
remove the obsolete and redundant text binding file.

Signed-off-by: Manish Baing <manishbaing2789 at gmail.com>
---
Changes in v3:
- Added 'required' properties to the pwm subnode in st,stmpe.yaml
  to close a validation gap identified by the Sashiko.
- Updated commit message and description to reflect MFD subsystem changes.

Changes in v2:
 - Droppped the TXT file instead of converting to YAML, as the
   functionality is already covered by st,stmpe.yaml.
   
 .../devicetree/bindings/mfd/st,stmpe.yaml      |  4 ++++
 .../devicetree/bindings/pwm/st,stmpe-pwm.txt   | 18 ------------------
 2 files changed, 4 insertions(+), 18 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/pwm/st,stmpe-pwm.txt

diff --git a/Documentation/devicetree/bindings/mfd/st,stmpe.yaml b/Documentation/devicetree/bindings/mfd/st,stmpe.yaml
index df43878fbe18..4bb05d544901 100644
--- a/Documentation/devicetree/bindings/mfd/st,stmpe.yaml
+++ b/Documentation/devicetree/bindings/mfd/st,stmpe.yaml
@@ -127,6 +127,10 @@ properties:
       "#pwm-cells":
         const: 2
 
+    required:
+      - compatible
+      - "#pwm-cells"
+
   touchscreen:
     type: object
     $ref: /schemas/input/touchscreen/touchscreen.yaml#
diff --git a/Documentation/devicetree/bindings/pwm/st,stmpe-pwm.txt b/Documentation/devicetree/bindings/pwm/st,stmpe-pwm.txt
deleted file mode 100644
index f401316e0248..000000000000
--- a/Documentation/devicetree/bindings/pwm/st,stmpe-pwm.txt
+++ /dev/null
@@ -1,18 +0,0 @@
-== ST STMPE PWM controller ==
-
-This is a PWM block embedded in the ST Microelectronics STMPE
-(ST Multi-Purpose Expander) chips. The PWM is registered as a
-subdevices of the STMPE MFD device.
-
-Required properties:
-- compatible: should be:
-  - "st,stmpe-pwm"
-- #pwm-cells: should be 2. See pwm.yaml in this directory for a description of
-  the cells format.
-
-Example:
-
-pwm0: pwm {
-	compatible = "st,stmpe-pwm";
-	#pwm-cells = <2>;
-};
-- 
2.43.0