Documentation/devicetree/bindings/net/ibm,emac.txt
Source file repositories/reference/linux-study-clean/Documentation/devicetree/bindings/net/ibm,emac.txt
File Facts
- System
- Linux kernel
- Corpus path
Documentation/devicetree/bindings/net/ibm,emac.txt- Extension
.txt- Size
- 8014 bytes
- Lines
- 206
- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
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>
- 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
Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.