dwc_eth_qos: Add Synopsys DWC Ethernet QoS bindings

Add device tree binding documentation for the Synopsys DWC Ethernet
QoS driver supporting revision 4.10a of the hardware IP.

Signed-off-by: Lars Persson <larper@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/devicetree/bindings/net/snps,dwc-qos-ethernet.txt b/Documentation/devicetree/bindings/net/snps,dwc-qos-ethernet.txt
new file mode 100644 (file)
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+* Synopsys DWC Ethernet QoS IP version 4.10 driver (GMAC)
+
+
+Required properties:
+- compatible: Should be "snps,dwc-qos-ethernet-4.10"
+- reg: Address and length of the register set for the device
+- clocks: Phandles to the reference clock and the bus clock
+- clock-names: Should be "phy_ref_clk" for the reference clock and "apb_pclk"
+  for the bus clock.
+- interrupt-parent: Should be the phandle for the interrupt controller
+  that services interrupts for this device
+- interrupts: Should contain the core's combined interrupt signal
+- phy-mode: See ethernet.txt file in the same directory
+
+Optional properties:
+- dma-coherent: Present if dma operations are coherent
+- mac-address: See ethernet.txt in the same directory
+- local-mac-address: See ethernet.txt in the same directory
+- snps,en-lpi: If present it enables use of the AXI low-power interface
+- snps,write-requests: Number of write requests that the AXI port can issue.
+  It depends on the SoC configuration.
+- snps,read-requests: Number of read requests that the AXI port can issue.
+  It depends on the SoC configuration.
+- snps,burst-map: Bitmap of allowed AXI burst lengts, with the LSB
+  representing 4, then 8 etc.
+- snps,txpbl: DMA Programmable burst length for the TX DMA
+- snps,rxpbl: DMA Programmable burst length for the RX DMA
+- snps,en-tx-lpi-clockgating: Enable gating of the MAC TX clock during
+  TX low-power mode.
+- phy-handle: See ethernet.txt file in the same directory
+- mdio device tree subnode: When the GMAC has a phy connected to its local
+    mdio, there must be device tree subnode with the following
+    required properties:
+    - compatible: Must be "snps,dwc-qos-ethernet-mdio".
+    - #address-cells: Must be <1>.
+    - #size-cells: Must be <0>.
+
+    For each phy on the mdio bus, there must be a node with the following
+    fields:
+
+    - reg: phy id used to communicate to phy.
+    - device_type: Must be "ethernet-phy".
+    - fixed-mode device tree subnode: see fixed-link.txt in the same directory
+
+Examples:
+ethernet2@40010000 {
+       clock-names = "phy_ref_clk", "apb_pclk";
+       clocks = <&clkc 17>, <&clkc 15>;
+       compatible = "snps,dwc-qos-ethernet-4.10";
+       interrupt-parent = <&intc>;
+       interrupts = <0x0 0x1e 0x4>;
+       reg = <0x40010000 0x4000>;
+       phy-handle = <&phy2>;
+       phy-mode = "gmii";
+
+       snps,en-tx-lpi-clockgating;
+       snps,en-lpi;
+       snps,write-requests = <2>;
+       snps,read-requests = <16>;
+       snps,burst-map = <0x7>;
+       snps,txpbl = <8>;
+       snps,rxpbl = <2>;
+
+       dma-coherent;
+
+       mdio {
+               #address-cells = <0x1>;
+               #size-cells = <0x0>;
+               phy2: phy@1 {
+                       compatible = "ethernet-phy-ieee802.3-c22";
+                       device_type = "ethernet-phy";
+                       reg = <0x1>;
+               };
+       };
+};