DT: net: document Ethernet bindings in one place

This patch is an attempt to gather the Ethernet related bindings in one file,
like it's done in the MMC and some other subsystems. It should save some of
the trouble of documenting several properties over and over in each binding
document, instead only making reference to the main file.

I have used the Embedded Power Architecture(TM) Platform Requirements (ePAPR)
standard as a base for the properties description, also documenting some ad-hoc
properties that have been introduced over time despite having direct analogs in
ePAPR.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 25 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/net/ethernet.txt b/Documentation/devicetree/bindings/net/ethernet.txt
new file mode 100644
index 000000000000..9ecd43d8792c
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/ethernet.txt
@@ -0,0 +1,25 @@
+The following properties are common to the Ethernet controllers:
+
+- local-mac-address: array of 6 bytes, specifies the MAC address that was
+  assigned to the network device;
+- mac-address: array of 6 bytes, specifies the MAC address that was last used by
+  the boot program; should be used in cases where the MAC address assigned to
+  the device by the boot program is different from the "local-mac-address"
+  property;
+- max-speed: number, specifies maximum speed in Mbit/s supported by the device;
+- max-frame-size: number, maximum transfer unit (IEEE defined MTU), rather than
+  the maximum frame size (there's contradiction in ePAPR).
+- phy-mode: string, operation mode of the PHY interface; supported values are
+  "mii", "gmii", "sgmii", "tbi", "rev-mii", "rmii", "rgmii", "rgmii-id",
+  "rgmii-rxid", "rgmii-txid", "rtbi", "smii", "xgmii"; this is now a de-facto
+  standard property;
+- phy-connection-type: the same as "phy-mode" property but described in ePAPR;
+- phy-handle: phandle, specifies a reference to a node representing a PHY
+  device; this property is described in ePAPR and so preferred;
+- phy: the same as "phy-handle" property, not recommended for new bindings.
+- phy-device: the same as "phy-handle" property, not recommended for new
+  bindings.
+
+Child nodes of the Ethernet controller are typically the individual PHY devices
+connected via the MDIO bus (sometimes the MDIO bus controller is separate).
+They are described in the phy.txt file in this same directory.