[net-next,v3,01/15] Documentation: ACPI: DSD: Document MDIO PHY

Commit Message

Calvin Johnson Jan. 12, 2021, 1:40 p.m. UTC

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 <[e-mail]>
---

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.rst

Comments

Randy Dunlap Jan. 18, 2021, 10:12 p.m. UTC | #1

Hi,

On 1/12/21 5:40 AM, Calvin Johnson wrote:
> 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 <[e-mail]>
> ---
> 
> 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.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..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 needs

ditto.

> +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.

Patch

diff --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
+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.
+
+::
+      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 needs
+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(PHYs on the mdiobus).
+
+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
+This node defines the PHYs that are connected to the MDIO bus, MDI0
+-------------------------------------------------------------------
+::
+	Scope(\_SB.MDI0)
+	{
+	  Device(PHY1) {
+	    Name (_ADR, 0x1)
+	  } // end of PHY1
+
+	  Device(PHY2) {
+	    Name (_ADR, 0x2)
+	  } // end of PHY2
+	}
+
+
+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