Commit 31a9ce20 authored by Oleksij Rempel's avatar Oleksij Rempel Committed by Paolo Abeni
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dt-bindings: net: ethernet-phy: Add timing-role role property for ethernet PHYs 



This patch introduces a new `timing-role` property in the device tree
bindings for configuring the master/slave role of PHYs. This is
essential for scenarios where hardware strap pins are unavailable or
incorrectly configured.

The `timing-role` property supports the following values:
- `forced-master`: Forces the PHY to operate as a master (clock source).
- `forced-slave`: Forces the PHY to operate as a slave (clock receiver).
- `preferred-master`: Prefers the PHY to be master but allows negotiation.
- `preferred-slave`: Prefers the PHY to be slave but allows negotiation.

The terms "master" and "slave" are retained in this context to align
with the IEEE 802.3 standards, where they are used to describe the roles
of PHY devices in managing clock signals for data transmission. In
particular, the terms are used in specifications for 1000Base-T and
MultiGBASE-T PHYs, among others. Although there is an effort to adopt
more inclusive terminology, replacing these terms could create
discrepancies between the Linux kernel and the established standards,
documentation, and existing hardware interfaces.

Signed-off-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: default avatarRob Herring (Arm) <robh@kernel.org>
Reviewed-by: default avatarFlorian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: default avatarDivya Koppera <divya.koppera@microchip.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 138d21b6

Documentation/devicetree/bindings/net/ethernet-phy.yaml

+21 −0
Original line number Diff line number Diff line
@@ -158,6 +158,27 @@ properties: 
      Mark the corresponding energy efficient ethernet mode as

      broken and request the ethernet to stop advertising it.



  timing-role:

    $ref: /schemas/types.yaml#/definitions/string

    enum:

      - forced-master

      - forced-slave

      - preferred-master

      - preferred-slave

    description: |

      Specifies the timing role of the PHY in the network link. This property is

      required for setups where the role must be explicitly assigned via the

      device tree due to limitations in hardware strapping or incorrect strap

      configurations.

      It is applicable to Single Pair Ethernet (1000/100/10Base-T1) and other

      PHY types, including 1000Base-T, where it controls whether the PHY should

      be a master (clock source) or a slave (clock receiver).



      - 'forced-master': The PHY is forced to operate as a master.

      - 'forced-slave': The PHY is forced to operate as a slave.

      - 'preferred-master': Prefer the PHY to be master but allow negotiation.

      - 'preferred-slave': Prefer the PHY to be slave but allow negotiation.



  pses:

    $ref: /schemas/types.yaml#/definitions/phandle-array

    maxItems: 1