Kernel-4.18.0-80.el8_ibm,emac

4xx/Axon EMAC ethernet nodes

The EMAC ethernet controller in IBM and AMCC 4xx chips, and also
the Axon bridge.  To operate this needs to interact with a this
special McMAL DMA controller, and sometimes an RGMII or ZMII
interface.  In addition to the nodes and properties described
below, the node for the OPB bus on which the EMAC sits must have a
correct clock-frequency property.

  i) The EMAC node itself

Required properties:
- device_type       : "network"

- compatible        : compatible list, contains 2 entries, first is
          "ibm,emac-CHIP" where CHIP is the host ASIC (440gx,
          405gp, Axon) and second is either "ibm,emac" or
          "ibm,emac4".  For Axon, thus, we have: "ibm,emac-axon",
          "ibm,emac4"
- interrupts        : <interrupt mapping for EMAC IRQ and WOL IRQ>
- interrupt-parent  : optional, if needed for interrupt mapping
- reg               : <registers mapping>
- local-mac-address : 6 bytes, MAC address
- mal-device        : phandle of the associated McMAL node
- mal-tx-channel    : 1 cell, index of the tx channel on McMAL associated
          with this EMAC
- mal-rx-channel    : 1 cell, index of the rx channel on McMAL associated
          with this EMAC
- cell-index        : 1 cell, hardware index of the EMAC cell on a given
          ASIC (typically 0x0 and 0x1 for EMAC0 and EMAC1 on
          each Axon chip)
- max-frame-size    : 1 cell, maximum frame size supported in bytes
- rx-fifo-size      : 1 cell, Rx fifo size in bytes for 10 and 100 Mb/sec
          operations.
          For Axon, 2048
- tx-fifo-size      : 1 cell, Tx fifo size in bytes for 10 and 100 Mb/sec
          operations.
          For Axon, 2048.
- fifo-entry-size   : 1 cell, size of a fifo entry (used to calculate
          thresholds).
          For Axon, 0x00000010
- mal-burst-size    : 1 cell, MAL burst size (used to calculate thresholds)
          in bytes.
          For Axon, 0x00000100 (I think ...)
- phy-mode          : string, mode of operations of the PHY interface.
          Supported values are: "mii", "rmii", "smii", "rgmii",
          "tbi", "gmii", rtbi", "sgmii".
          For Axon on CAB, it is "rgmii"
- mdio-device       : 1 cell, required iff using shared MDIO registers
          (440EP).  phandle of the EMAC to use to drive the
          MDIO lines for the PHY used by this EMAC.
- zmii-device       : 1 cell, required iff connected to a ZMII.  phandle of
          the ZMII device node
- zmii-channel      : 1 cell, required iff connected to a ZMII.  Which ZMII
          channel or 0xffffffff if ZMII is only used for MDIO.
- rgmii-device      : 1 cell, required iff connected to an RGMII. phandle
          of the RGMII device node.
          For Axon: phandle of plb5/plb4/opb/rgmii
- rgmii-channel     : 1 cell, required iff connected to an RGMII.  Which
          RGMII channel is used by this EMAC.
          Fox Axon: present, whatever value is appropriate for each
          EMAC, that is the content of the current (bogus) "phy-port"
          property.

Optional properties:
- phy-address       : 1 cell, optional, MDIO address of the PHY. If absent,
          a search is performed.
- phy-map           : 1 cell, optional, bitmap of addresses to probe the PHY
          for, used if phy-address is absent. bit 0x00000001 is
          MDIO address 0.
          For Axon it can be absent, though my current driver
          doesn't handle phy-address yet so for now, keep
          0x00ffffff in it.
- phy-handle    : Used to describe configurations where a external PHY
          is used. Please refer to:
          Documentation/devicetree/bindings/net/ethernet.txt
- rx-fifo-size-gige : 1 cell, Rx fifo size in bytes for 1000 Mb/sec
          operations (if absent the value is the same as
          rx-fifo-size).  For Axon, either absent or 2048.
- tx-fifo-size-gige : 1 cell, Tx fifo size in bytes for 1000 Mb/sec
          operations (if absent the value is the same as
          tx-fifo-size). For Axon, either absent or 2048.
- tah-device        : 1 cell, optional. If connected to a TAH engine for
          offload, phandle of the TAH device node.
- tah-channel       : 1 cell, optional. If appropriate, channel used on the
          TAH engine.
- fixed-link    : Fixed-link subnode describing a link to a non-MDIO
          managed entity. See
          Documentation/devicetree/bindings/net/fixed-link.txt
          for details.
- mdio subnode    : When the EMAC has a phy connected to its local
          mdio, which us supported by the kernel's network
          PHY library in drivers/net/phy, there must be device
          tree subnode with the following required properties:
            - #address-cells: Must be <1>.
            - #size-cells: Must be <0>.

          For PHY definitions: Please refer to
          Documentation/devicetree/bindings/net/phy.txt and
          Documentation/devicetree/bindings/net/ethernet.txt

Examples:

EMAC0: ethernet@40000800 {
    device_type = "network";
    compatible = "ibm,emac-440gp", "ibm,emac";
    interrupt-parent = <&UIC1>;
    interrupts = <1c 4 1d 4>;
    reg = <40000800 70>;
    local-mac-address = [00 04 AC E3 1B 1E];
    mal-device = <&MAL0>;
    mal-tx-channel = <0 1>;
    mal-rx-channel = <0>;
    cell-index = <0>;
    max-frame-size = <5dc>;
    rx-fifo-size = <1000>;
    tx-fifo-size = <800>;
    phy-mode = "rmii";
    phy-map = <00000001>;
    zmii-device = <&ZMII0>;
    zmii-channel = <0>;
};

EMAC1: ethernet@ef600c00 {
    device_type = "network";
    compatible = "ibm,emac-apm821xx", "ibm,emac4sync";
    interrupt-parent = <&EMAC1>;
    interrupts = <0 1>;
    #interrupt-cells = <1>;
    #address-cells = <0>;
    #size-cells = <0>;
    interrupt-map = <0 &UIC2 0x10 IRQ_TYPE_LEVEL_HIGH /* Status */
             1 &UIC2 0x14 IRQ_TYPE_LEVEL_HIGH /* Wake */>;
    reg = <0xef600c00 0x000000c4>;
    local-mac-address = [000000000000]; /* Filled in by U-Boot */
    mal-device = <&MAL0>;
    mal-tx-channel = <0>;
    mal-rx-channel = <0>;
    cell-index = <0>;
    max-frame-size = <9000>;
    rx-fifo-size = <16384>;
    tx-fifo-size = <2048>;
    fifo-entry-size = <10>;
    phy-mode = "rgmii";
    phy-handle = <&phy0>;
    phy-map = <0x00000000>;
    rgmii-device = <&RGMII0>;
    rgmii-channel = <0>;
    tah-device = <&TAH0>;
    tah-channel = <0>;
    has-inverted-stacr-oc;
    has-new-stacr-staopc;

        mdio {
        #address-cells = <1>;
        #size-cells = <0>;

        phy0: ethernet-phy@0 {
            compatible = "ethernet-phy-ieee802.3-c22";
            reg = <0>;
        };
    };
};


  ii) McMAL node

Required properties:
- device_type        : "dma-controller"
- compatible         : compatible list, containing 2 entries, first is
           "ibm,mcmal-CHIP" where CHIP is the host ASIC (like
           emac) and the second is either "ibm,mcmal" or
           "ibm,mcmal2".
           For Axon, "ibm,mcmal-axon","ibm,mcmal2"
- interrupts         : <interrupt mapping for the MAL interrupts sources:
                       5 sources: tx_eob, rx_eob, serr, txde, rxde>.
                       For Axon: This is _different_ from the current
           firmware.  We use the "delayed" interrupts for txeob
           and rxeob. Thus we end up with mapping those 5 MPIC
           interrupts, all level positive sensitive: 10, 11, 32,
           33, 34 (in decimal)
- dcr-reg            : < DCR registers range >
- dcr-parent         : if needed for dcr-reg
- num-tx-chans       : 1 cell, number of Tx channels
- num-rx-chans       : 1 cell, number of Rx channels

  iii) ZMII node

Required properties:
- compatible         : compatible list, containing 2 entries, first is
           "ibm,zmii-CHIP" where CHIP is the host ASIC (like
           EMAC) and the second is "ibm,zmii".
           For Axon, there is no ZMII node.
- reg                : <registers mapping>

  iv) RGMII node

Required properties:
- compatible         : compatible list, containing 2 entries, first is
           "ibm,rgmii-CHIP" where CHIP is the host ASIC (like
           EMAC) and the second is "ibm,rgmii".
                       For Axon, "ibm,rgmii-axon","ibm,rgmii"
- reg                : <registers mapping>
- revision           : as provided by the RGMII new version register if
           available.
           For Axon: 0x0000012a