Messages in this thread | | | Subject | Re: [PATCH net-next v8 01/15] Documentation: ACPI: DSD: Document MDIO PHY | From | Grant Likely <> | Date | Thu, 10 Jun 2021 19:11:38 +0100 |
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On 10/06/2021 17:39, Ioana Ciornei wrote: > From: Calvin Johnson <calvin.johnson@oss.nxp.com> > > 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 <calvin.johnson@oss.nxp.com> > Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Looks reasonable to me. I'm not a kernel maintainer any more, so my Acked-by: may not be very valuable, but here it is anyway:
Acked-by: Grant Likely <grant.likely@arm.com>
> --- > > Changes in v8: None > Changes in v7: None > Changes in v6: > - Minor cleanup > > Changes in v5: > - More cleanup > > Changes in v4: > - More cleanup > > Changes in v3: None > Changes in v2: > - Updated with more description in document > > Documentation/firmware-guide/acpi/dsd/phy.rst | 133 ++++++++++++++++++ > 1 file changed, 133 insertions(+) > create mode 100644 Documentation/firmware-guide/acpi/dsd/phy.rst > > diff --git a/Documentation/firmware-guide/acpi/dsd/phy.rst b/Documentation/firmware-guide/acpi/dsd/phy.rst > new file mode 100644 > index 000000000000..7d01ae8b3cc6 > --- /dev/null > +++ b/Documentation/firmware-guide/acpi/dsd/phy.rst > @@ -0,0 +1,133 @@ > +.. 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 their respective MACs, the PHYs registered > +on the MDIO bus have to be referenced. > + > +This document introduces two _DSD properties that are to be used > +for connecting PHYs on the MDIO bus [3] to the MAC layer. > + > +These properties are defined in accordance with the "Device > +Properties UUID For _DSD" [2] document and the > +daffd814-6eba-4d8c-8a91-bc9bbf4aa301 UUID must be used in the Device > +Data Descriptors containing them. > + > +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. > + > +:: > + 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, the MAC driver needs > +references to the previously registered PHYs which are provided > +as device object references (e.g. \_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]. > + > +The following ASL example illustrates the usage of these properties. > + > +DSDT entry for MDIO node > +------------------------ > + > +The MDIO bus has an SoC component (MDIO controller) and a platform > +component (PHYs on the MDIO bus). > + > +a) Silicon Component > +This node describes the MDIO controller, MDI0 > +--------------------------------------------- > +:: > + 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 > +The PHY1 and PHY2 nodes represent the PHYs connected to MDIO bus MDI0 > +--------------------------------------------------------------------- > +:: > + Scope(\_SB.MDI0) > + { > + Device(PHY1) { > + Name (_ADR, 0x1) > + } // end of PHY1 > + > + Device(PHY2) { > + Name (_ADR, 0x2) > + } // end of PHY2 > + } > + > +DSDT entries representing MAC nodes > +----------------------------------- > + > +Below are the MAC nodes where PHY nodes are referenced. > +phy-mode and phy-handle are used as explained earlier. > +------------------------------------------------------ > +:: > + Scope(\_SB.MCE0.PR17) > + { > + Name (_DSD, Package () { > + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), > + Package () { > + Package (2) {"phy-mode", "rgmii-id"}, > + Package (2) {"phy-handle", \_SB.MDI0.PHY1} > + } > + }) > + } > + > + Scope(\_SB.MCE0.PR18) > + { > + Name (_DSD, Package () { > + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), > + Package () { > + Package (2) {"phy-mode", "rgmii-id"}, > + Package (2) {"phy-handle", \_SB.MDI0.PHY2}} > + } > + }) > + } > + > +References > +========== > + > +[1] Documentation/networking/phy.rst > + > +[2] https://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf > + > +[3] Documentation/firmware-guide/acpi/DSD-properties-rules.rst > + > +[4] Documentation/devicetree/bindings/net/ethernet-controller.yaml >
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