[PATCH 4/4] dt-bindings: Document the DT bindings for lan78xx

[Phil Elwell]

The Microchip LAN78XX family of devices are Ethernet controllers with
a USB interface. Despite being discoverable devices it can be useful to
be able to configure them from Device Tree, particularly in low-cost
applications without an EEPROM or programmed OTP.

Document the supported properties in a bindings file, adding it to
MAINTAINERS at the same time.

Signed-off-by: Phil Elwell <phil@xxxxxxxxxxxxxxx>
---
 .../devicetree/bindings/net/microchip,lan78xx.txt  | 44 ++++++++++++++++++++++
 MAINTAINERS                                        |  1 +
 2 files changed, 45 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/microchip,lan78xx.txt

diff --git a/Documentation/devicetree/bindings/net/microchip,lan78xx.txt b/Documentation/devicetree/bindings/net/microchip,lan78xx.txt
new file mode 100644
index 0000000..e7d7850
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/microchip,lan78xx.txt
@@ -0,0 +1,44 @@
+Microchip LAN78xx Gigabit Ethernet controller
+
+The LAN78XX devices are usually configured by programming their OTP or with
+an external EEPROM, but some platforms (e.g. Raspberry Pi 3 B+) have neither.
+
+Please refer to ethernet.txt for a description of common Ethernet bindings.
+
+Optional properties:
+- microchip,eee-enabled: if present, enable Energy Efficient Ethernet support;
+- microchip,led-modes: a two-element vector, with each element configuring
+  the operating mode of an LED. The values supported by the device are;
+  0: Link/Activity
+  1: Link1000/Activity
+  2: Link100/Activity
+  3: Link10/Activity
+  4: Link100/1000/Activity
+  5: Link10/1000/Activity
+  6: Link10/100/Activity
+  7: RESERVED
+  8: Duplex/Collision
+  9: Collision
+  10: Activity
+  11: RESERVED
+  12: Auto-negotiation Fault
+  13: RESERVED
+  14: Off
+  15: On
+- microchip,tx-lpi-timer: the delay (in microseconds) between the TX fifo
+  becoming empty and invoking Low Power Idles (default 600).
+
+Example:
+
+	/* Standard configuration for a Raspberry Pi 3 B+ */
+	ethernet: usbether@1 {
+		compatible = "usb424,7800";
+		reg = <1>;
+		microchip,eee-enabled;
+		microchip,tx-lpi-timer = <600>;
+		/*
+		 * led0 = 1:link1000/activity
+		 * led1 = 6:link10/100/activity
+		 */
+		microchip,led-modes = <1 6>;
+	};
diff --git a/MAINTAINERS b/MAINTAINERS
index 2328eed..b637aad 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14482,6 +14482,7 @@ M:	Microchip Linux Driver Support <UNGLinuxDriver@xxxxxxxxxxxxx>
 L:	netdev@xxxxxxxxxxxxxxx
 S:	Maintained
 F:	drivers/net/usb/lan78xx.*
+F:	Documentation/devicetree/bindings/net/microchip,lan78xx.txt
 
 USB MASS STORAGE DRIVER
 M:	Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
-- 
2.7.4