[PATCH net-next v3 3/4] dt-bindings: net: mdio: add phy-id-read-needs-reset property

[Buday Csaba <buday.csaba@prolan.hu>]

Some Ethernet PHYs require a hard reset before accessing their MDIO
registers. When the ID is not provided by a compatible string,
reading the PHY ID may fail on such devices.

This patch introduces a new device tree property called
`phy-id-read-needs-reset`, which can be used to hard reset the
PHY before attempting to read its ID via MDIO.

Signed-off-by: Buday Csaba <buday.csaba@prolan.hu>
---
V2 -> V3: unchanged
V1 -> V2: added this DT binding
---
 Documentation/devicetree/bindings/net/ethernet-phy.yaml | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
index 2ec2d9fda..b570f8038 100644
--- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml
+++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
@@ -215,6 +215,14 @@ properties:
       Delay after the reset was deasserted in microseconds. If
       this property is missing the delay will be skipped.
 
+  phy-id-read-needs-reset:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      Some PHYs require a hard reset before accessing MDIO registers.
+      This workaround allows auto-detection of the PHY ID in such cases.
+      When the PHY ID is provided with the 'compatible' string, setting
+      this property has no effect.
+
   sfp:
     $ref: /schemas/types.yaml#/definitions/phandle
     description:
-- 
2.39.5