new file mode 100644
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+.. SPDX-License-Identifier: GPL-2.0
+
+=========================
+MDIO bus and PHYs in ACPI
+=========================
+
+The PHYs on an mdiobus are probed and registered using mdiobus_register().
+Later, for connecting these PHYs to MAC, the PHYs registered on the
+mdiobus have to be referenced.
+
+mdio-handle
+-----------
+For each MAC node, a property "mdio-handle" is used to reference the
+MDIO bus on which the PHYs are registered. On getting hold of the MDIO
+bus, use find_phy_device() to get the PHY connected to the MAC.
+
+phy-channel
+-----------
+Property "phy-channel" defines the address of the PHY on the mdiobus.
+
+phy-mode
+--------
+Property "phy-mode" defines the type of PHY interface.
+
+An example of this is shown below::
+
+DSDT entry for MAC where MDIO node is referenced
+------------------------------------------------
+ Scope(\_SB.MCE0.PR17) // 1G
+ {
+ Name (_DSD, Package () {
+ ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ Package () {
+ Package () {"phy-channel", 1},
+ Package () {"phy-mode", "rgmii-id"},
+ Package () {"mdio-handle", Package (){\_SB.MDI0}}
+ }
+ })
+ }
+
+ Scope(\_SB.MCE0.PR18) // 1G
+ {
+ Name (_DSD, Package () {
+ ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ Package () {
+ Package () {"phy-channel", 2},
+ Package () {"phy-mode", "rgmii-id"},
+ Package () {"mdio-handle", Package (){\_SB.MDI0}}
+ }
+ })
+ }
+
+DSDT entry for MDIO node
+------------------------
+a) Silicon Component
+--------------------
+ Scope(_SB)
+ {
+ Device(MDI0) {
+ Name(_HID, "NXP0006")
+ Name(_CCA, 1)
+ Name(_UID, 0)
+ Name(_CRS, ResourceTemplate() {
+ Memory32Fixed(ReadWrite, MDI0_BASE, MDI_LEN)
+ Interrupt(ResourceConsumer, Level, ActiveHigh, Shared)
+ {
+ MDI0_IT
+ }
+ }) // end of _CRS for MDI0
+ Name (_DSD, Package () {
+ ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ Package () {
+ Package () {"little-endian", 1},
+ }
+ })
+ } // end of MDI0
+ }
+
+b) Platform Component
+---------------------
+ Scope(\_SB.MDI0)
+ {
+ Device(PHY1) {
+ Name (_ADR, 0x1)
+ } // end of PHY1
+
+ Device(PHY2) {
+ Name (_ADR, 0x2)
+ } // end of PHY2
+ }
Introduce ACPI mechanism to get PHYs registered on a MDIO bus and provide them to be connected to MAC. An ACPI node property "mdio-handle" is introduced to reference the MDIO bus on which PHYs are registered with autoprobing method used by mdiobus_register(). Describe properties "phy-channel" and "phy-mode" Signed-off-by: Calvin Johnson <calvin.johnson@oss.nxp.com> --- Changes in v6: None Changes in v5: None Changes in v4: None Changes in v3: - cleanup based on v2 comments - Added description for more properties - Added MDIO node DSDT entry Changes in v2: None Documentation/firmware-guide/acpi/dsd/phy.rst | 90 +++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 Documentation/firmware-guide/acpi/dsd/phy.rst