Re: [net-next PATCH v3 01/15] Documentation: ACPI: DSD: Document MDIO PHY
From: Randy Dunlap <hidden>
Date: 2021-01-18 22:14:10
Also in:
linux-acpi, linux-arm-kernel, lkml
Hi, On 1/12/21 5:40 AM, Calvin Johnson wrote:
quoted hunk ↗ jump to hunk
Introduce ACPI mechanism to get PHYs registered on a MDIO bus and provide them to be connected to MAC. Describe properties "phy-handle" and "phy-mode". Signed-off-by: Calvin Johnson <redacted> --- Changes in v3: None Changes in v2: - Updated with more description in document Documentation/firmware-guide/acpi/dsd/phy.rst | 129 ++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 Documentation/firmware-guide/acpi/dsd/phy.rstdiff --git a/Documentation/firmware-guide/acpi/dsd/phy.rst b/Documentation/firmware-guide/acpi/dsd/phy.rst new file mode 100644 index 000000000000..a2e4fdcdbf53 --- /dev/null +++ b/Documentation/firmware-guide/acpi/dsd/phy.rst@@ -0,0 +1,129 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========================= +MDIO bus and PHYs in ACPI +========================= + +The PHYs on an MDIO bus [1] are probed and registered using +fwnode_mdiobus_register_phy(). +Later, for connecting these PHYs to MAC, the PHYs registered on the +mdiobus have to be referenced. + +UUID given below should be used as mentioned in the "Device Properties
The UUID given below
+UUID For _DSD" [2] document. + - UUID: daffd814-6eba-4d8c-8a91-bc9bbf4aa301 + +This document introduces two _DSD properties that are to be used +for PHYs on the MDIO bus.[3] + +phy-handle +---------- +For each MAC node, a device property "phy-handle" is used to reference +the PHY that is registered on an MDIO bus. This is mandatory for +network interfaces that have PHYs connected to MAC via MDIO bus. + +During the MDIO bus driver initialization, PHYs on this bus are probed +using the _ADR object as shown below and are registered on the mdio bus.
s/mdio/MDIO/ (please be consistent, as 3 lines above)
+
+::
+ Scope(\_SB.MDI0)
+ {
+ Device(PHY1) {
+ Name (_ADR, 0x1)
+ } // end of PHY1
+
+ Device(PHY2) {
+ Name (_ADR, 0x2)
+ } // end of PHY2
+ }
+
+Later, during the MAC driver initialization, the registered PHY devices
+have to be retrieved from the mdio bus. For this, MAC driver needsditto.
+reference to the previously registered PHYs which are provided
+using reference to the device as {\_SB.MDI0.PHY1}.
+
+phy-mode
+--------
+The "phy-mode" _DSD property is used to describe the connection to
+the PHY. The valid values for "phy-mode" are defined in [4].
+
+
+An ASL example of this is shown below.
+
+DSDT entry for MDIO node
+------------------------
+The MDIO bus has an SoC component(mdio controller) and a platform
component (MDIO controller)
+component(PHYs on the mdiobus).
component (PHYs
+ +a) Silicon Component +This node describes the MDIO controller,MDI0
controller, MDI0
+--------------------------------------------
and then one more '-', please.
+::
+ 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
+ } // end of MDI0
+ }
+
+b) Platform Component
+This node defines the PHYs that are connected to the MDIO bus, MDI0
+-------------------------------------------------------------------[deletia] thanks. -- ~Randy You can't do anything without having to do something else first. -- Belefant's Law