Motorcomm yt8xxx PHY properties (_DSD)

This document describes ACPI _DSD device properties for Motorcomm yt8xxx Ethernet PHYs supported by the in-kernel driver in drivers/net/phy/motorcomm.c.

The properties are exposed on the PHY device object under the MDIO bus ACPI device (the same objects that are registered via fwnode_mdiobus_register_phy()). MAC-side connection properties such as phy-handle and phy-mode are documented in [acpi-mdio-phy].

Property names and semantics are intentionally aligned with the Devicetree binding [motorcomm-yt8xxx] so that the same driver code path (device_property_* on &phydev->mdio.dev) can consume firmware described either as Devicetree or ACPI _DSD.

UUID and placement

Per [acpi-dsd-properties-rules] and [acpi-mdio-phy], properties must be placed in an _DSD package using the standard Device Properties UUID:

ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301")

Properties

Unless noted otherwise, integer properties use the same allowed values and defaults as [motorcomm-yt8xxx].

rx-internal-delay-ps (u32, optional)

RGMII RX internal delay in picoseconds. Only meaningful when the link is using RGMII modes with RX internal delay; see [motorcomm-yt8xxx].

tx-internal-delay-ps (u32, optional)

RGMII TX internal delay in picoseconds. Only meaningful when the link is using RGMII modes with TX internal delay; see [motorcomm-yt8xxx].

motorcomm,clk-out-frequency-hz (u32, optional)

Clock output frequency on the PHY clock output pin. Allowed values and default are defined in [motorcomm-yt8xxx].

motorcomm,keep-pll-enabled (boolean, optional)

If true, keep the PLL enabled even when there is no link (useful for using the clock output without an Ethernet link). See [motorcomm-yt8xxx].

motorcomm,auto-sleep-disabled (boolean, optional)

If true, disable the PHY auto-sleep behavior described in [motorcomm-yt8xxx].

motorcomm,rx-clk-drv-microamp (u32, optional)

Drive strength for the rx_clk RGMII pad in microamps. Allowed values depend on the configured RGMII LDO voltage; see [motorcomm-yt8xxx].

motorcomm,rx-data-drv-microamp (u32, optional)

Drive strength for the rx_data and rx_ctl RGMII pads in microamps. See [motorcomm-yt8xxx].

motorcomm,tx-clk-adj-enabled (boolean, optional)

Enables adjustments related to motorcomm,tx-clk-*-inverted usage; see [motorcomm-yt8xxx].

motorcomm,tx-clk-10-inverted (boolean, optional) motorcomm,tx-clk-100-inverted (boolean, optional) motorcomm,tx-clk-1000-inverted (boolean, optional)

Per-speed TX clock inversion options; see [motorcomm-yt8xxx].

ASL example (illustrative)

The example below only shows PHY-local _DSD properties. A real platform still needs a MAC phy-handle and phy-mode package as in [acpi-mdio-phy].

Scope (\_SB.MDI0)
{
        Device (PHY4)
        {
                Name (_ADR, 0x4)

                Name (_DSD, Package () {
                        ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
                        Package () {
                                Package (2) { "rx-internal-delay-ps", 2100 },
                                Package (2) { "tx-internal-delay-ps", 150 },
                                Package (2) { "motorcomm,clk-out-frequency-hz", 0 },
                                Package (2) { "motorcomm,keep-pll-enabled", 1 },
                                Package (2) { "motorcomm,auto-sleep-disabled", 1 },
                        }
                })
        }
}

References

[acpi-mdio-phy] (1,2,3)

MDIO bus and PHYs in ACPI

[motorcomm-yt8xxx] (1,2,3,4,5,6,7,8,9,10,11)

Documentation/devicetree/bindings/net/motorcomm,yt8xxx.yaml