acpi/dsd/phy.rst

1 .. SPDX-License-Identifier: GPL-2.0
4 MDIO bus and PHYs in ACPI
7 The PHYs on an MDIO bus [phy] are probed and registered using
11 on the MDIO bus have to be referenced.
14 for connecting PHYs on the MDIO bus [dsd-properties-rules] to the MAC layer.
17 Properties UUID For _DSD" [dsd-guide] document and the
18 daffd814-6eba-4d8c-8a91-bc9bbf4aa301 UUID must be used in the Device
21 phy-handle
22 ----------
23 For each MAC node, a device property "phy-handle" is used to reference
24 the PHY that is registered on an MDIO bus. This is mandatory for
25 network interfaces that have PHYs connected to MAC via MDIO bus.
27 During the MDIO bus driver initialization, PHYs on this bus are probed
28 using the _ADR object as shown below and are registered on the MDIO bus.
30 .. code-block:: none
44 have to be retrieved from the MDIO bus. For this, the MAC driver needs
48 phy-mode
49 --------
50 The "phy-mode" _DSD property is used to describe the connection to
51 the PHY. The valid values for "phy-mode" are defined in [ethernet-controller].
54 -------
56 The valid values for "managed" are defined in [ethernet-controller].
58 fixed-link
59 ----------
60 The "fixed-link" is described by a data-only subnode of the
62 hierarchical data extension (UUID dbb8e3e6-5886-4ba6-8795-1319f52a966b
63 in accordance with [dsd-guide] "_DSD Implementation Guide" document).
65 possibly the optional ones - complete list of parameters and
66 their values are specified in [ethernet-controller].
70 DSDT entry for MDIO node
71 ------------------------
73 The MDIO bus has an SoC component (MDIO controller) and a platform
74 component (PHYs on the MDIO bus).
77 This node describes the MDIO controller, MDI0
78 ---------------------------------------------
80 .. code-block:: none
99 The PHY1 and PHY2 nodes represent the PHYs connected to MDIO bus MDI0
100 ---------------------------------------------------------------------
102 .. code-block:: none
116 -----------------------------------
119 phy-mode and phy-handle are used as explained earlier.
120 ------------------------------------------------------
122 .. code-block:: none
127 	     ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
129 		     Package (2) {"phy-mode", "rgmii-id"},
130 		     Package (2) {"phy-handle", \_SB.MDI0.PHY1}
138 	    ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
140 		    Package (2) {"phy-mode", "rgmii-id"},
141 		    Package (2) {"phy-handle", \_SB.MDI0.PHY2}}
147 -------------------------------------------------------
149 .. code-block:: none
154 	     ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
156 		     Package () {"phy-mode", "sgmii"},
157 		     Package () {"managed", "in-band-status"}
162 MAC node example with a "fixed-link" subnode.
163 ---------------------------------------------
165 .. code-block:: none
170 	    ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
172 		     Package () {"phy-mode", "sgmii"},
174 	    ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
176 		     Package () {"fixed-link", "LNK0"}
179 	  Name (LNK0, Package(){ // Data-only subnode of port
180 	    ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
183 		     Package () {"full-duplex", 1}
193 [dsd-properties-rules]
194     Documentation/firmware-guide/acpi/DSD-properties-rules.rst
196 [ethernet-controller]
197     Documentation/devicetree/bindings/net/ethernet-controller.yaml
199 [dsd-guide] DSD Guide.
200     https://github.com/UEFI/DSD-Guide/blob/main/dsd-guide.adoc, referenced
201     2021-11-30.