dt-bindings: Document the DT bindings for lan78xx

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.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/devicetree/bindings/net/microchip,lan78xx.txt b/Documentation/devicetree/bindings/net/microchip,lan78xx.txt
new file mode 100644 (file)
index 0000000..76786a0
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/microchip,lan78xx.txt
@@ -0,0 +1,54 @@
+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.
+The Device Tree properties, if present, override the OTP and EEPROM.
+
+Required properties:
+- compatible: Should be one of "usb424,7800", "usb424,7801" or "usb424,7850".
+
+Optional properties:
+- local-mac-address:   see ethernet.txt
+- mac-address:         see ethernet.txt
+
+Optional properties of the embedded PHY:
+- microchip,led-modes: a 0..4 element vector, with each element configuring
+  the operating mode of an LED. Omitted LEDs are turned off. Allowed values
+  are defined in "include/dt-bindings/net/microchip-lan78xx.h".
+
+Example:
+
+/* Based on the configuration for a Raspberry Pi 3 B+ */
+&usb {
+       usb-port@1 {
+               compatible = "usb424,2514";
+               reg = <1>;
+               #address-cells = <1>;
+               #size-cells = <0>;
+
+               usb-port@1 {
+                       compatible = "usb424,2514";
+                       reg = <1>;
+                       #address-cells = <1>;
+                       #size-cells = <0>;
+
+                       ethernet: ethernet@1 {
+                               compatible = "usb424,7800";
+                               reg = <1>;
+                               local-mac-address = [ 00 11 22 33 44 55 ];
+
+                               mdio {
+                                       #address-cells = <0x1>;
+                                       #size-cells = <0x0>;
+                                       eth_phy: ethernet-phy@1 {
+                                               reg = <1>;
+                                               microchip,led-modes = <
+                                                       LAN78XX_LINK_1000_ACTIVITY
+                                                       LAN78XX_LINK_10_100_ACTIVITY
+                                               >;
+                                       };
+                               };
+                       };
+               };
+       };
+};

diff --git a/MAINTAINERS b/MAINTAINERS
index c952d30..8146570 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14571,6 +14571,7 @@ M:      Woojung Huh <woojung.huh@microchip.com>
 M:     Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>
 L:     netdev@vger.kernel.org
 S:     Maintained
+F:     Documentation/devicetree/bindings/net/microchip,lan78xx.txt
 F:     drivers/net/usb/lan78xx.*
 F:     include/dt-bindings/net/microchip-lan78xx.h