[PATCH v3] dt-bindings: phy: mediatek: tphy: add a property for power-domains

[Macpaul Lin]

Include the MediaTek TPHY in a power domain.  Add the 'power-domains'
property in the Device Tree (DT) Schema and set 'maxItems: 1'.

Also, include a reminder in the description of the 'power-domains'
property.

Signed-off-by: Macpaul Lin <macpaul.lin at mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski at linaro.org>
---
 .../devicetree/bindings/phy/mediatek,tphy.yaml         | 10 ++++++++++
 1 file changed, 10 insertions(+)

Changes for v2:
 - Add a reminder in description of 'power-domains' property.
 - Fix commit message from v1.

Changes for v3:
 - Use 'imperative mood' keyword in the prompt of chatGPT to refine the commit
   message.
 - Add 'Acked-by:' tag, thanks for the review and grammer tool sharing.

diff --git a/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml b/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml
index 423b7c4e62f2..6be3aa4557e5 100644
--- a/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml
+++ b/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml
@@ -125,6 +125,16 @@ properties:
     $ref: /schemas/types.yaml#/definitions/uint32
     default: 28
 
+  power-domains:
+    description:
+      The TPHY of MediaTek should exist within a power domain. The
+      developer should be aware that the hardware design of MediaTek TPHY
+      does not require the addition of MTCMOS. If the power to the TPHY
+      is turned off, it will impact other functions. From the current
+      perspective of USB hardware design, even if MTCMOS is added to the
+      TPHY, it should remain always on.
+    maxItems: 1
+
 # Required child node:
 patternProperties:
   "^(usb|pcie|sata)-phy@[0-9a-f]+$":
-- 
2.45.2