[v3, PATCH 2/2] dt-binding: mediatek-dwmac: add binding document for MediaTek MT2712 DWMAC

[Biao Huang <biao.huang@mediatek.com>]

The commit adds the device tree binding documentation for the MediaTek DWMAC
found on MediaTek MT2712.

Change-Id: I3728666bf65927164bd82fa8dddb90df8270bd44
Signed-off-by: Biao Huang <biao.huang@mediatek.com>
---
 .../devicetree/bindings/net/mediatek-dwmac.txt     |   77 ++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/mediatek-dwmac.txt

diff --git a/Documentation/devicetree/bindings/net/mediatek-dwmac.txt b/Documentation/devicetree/bindings/net/mediatek-dwmac.txt
new file mode 100644
index 0000000..7fd56e0
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/mediatek-dwmac.txt
@@ -0,0 +1,77 @@
+MediaTek DWMAC glue layer controller
+
+This file documents platform glue layer for stmmac.
+Please see stmmac.txt for the other unchanged properties.
+
+The device node has following properties.
+
+Required properties:
+- compatible:  Should be "mediatek,mt2712-gmac" for MT2712 SoC
+- reg:  Address and length of the register set for the device
+- interrupts:  Should contain the MAC interrupts
+- interrupt-names: Should contain a list of interrupt names corresponding to
+	the interrupts in the interrupts property, if available.
+	Should be "macirq" for the main MAC IRQ
+- clocks: Must contain a phandle for each entry in clock-names.
+- clock-names: The name of the clock listed in the clocks property. These are
+	"axi", "apb", "mac_ext", "mac_parent", "ptp_ref", "ptp_parent", "ptp_top"
+	for MT2712 SoC
+- mac-address: See ethernet.txt in the same directory
+- phy-mode: See ethernet.txt in the same directory
+
+Optional properties:
+- tx-delay: TX clock delay macro value. Range is 0~31. Default is 0.
+	It should be defined for rgmii/rgmii-rxid/mii interface.
+- rx-delay: RX clock delay macro value. Range is 0~31. Default is 0.
+	It should be defined for rgmii/rgmii-txid/mii/rmii interface.
+- fine-tune: This property will select coarse-tune delay or fine delay
+	for rgmii interface.
+	If fine-tune delay is enabled, tx-delay/rx-delay is 170+/-50ps
+	per stage.
+	Else coarse-tune delay is enabled, tx-delay/rx-delay is 0.55+/-0.2ns
+	per stage.
+	This property do not apply to non-rgmii PHYs.
+	Only coarse-tune delay is supported for mii/rmii PHYs.
+- rmii-rxc: Reference clock of rmii is from external PHYs,
+	and it can be connected to TXC or RXC pin on MT2712 SoC.
+	If ref_clk <--> TXC, disable it.
+	Else ref_clk <--> RXC, enable it.
+- txc-inverse: Inverse tx clock for mii/rgmii.
+	Inverse tx clock inside MAC relative to reference clock for rmii,
+	and it rarely happen.
+- rxc-inverse: Inverse rx clock for mii/rgmii interfaces.
+	Inverse reference clock for rmii.
+
+Example:
+	eth: ethernet@1101c000 {
+		compatible = "mediatek,mt2712-gmac";
+		reg = <0 0x1101c000 0 0x1300>;
+		interrupts = <GIC_SPI 237 IRQ_TYPE_LEVEL_LOW>;
+		interrupt-names = "macirq";
+		phy-mode ="rgmii-id";
+		mac-address = [00 55 7b b5 7d f7];
+		clock-names = "axi",
+			      "apb",
+			      "mac_ext",
+			      "mac_parent",
+			      "ptp_ref",
+			      "ptp_parent",
+			      "ptp_top";
+		clocks = <&pericfg CLK_PERI_GMAC>,
+			 <&pericfg CLK_PERI_GMAC_PCLK>,
+			 <&topckgen CLK_TOP_ETHER_125M_SEL>,
+			 <&topckgen CLK_TOP_ETHERPLL_125M>,
+			 <&topckgen CLK_TOP_ETHER_50M_SEL>,
+			 <&topckgen CLK_TOP_APLL1_D3>,
+			 <&topckgen CLK_TOP_APLL1>;
+		snps,txpbl = <32>;
+		snps,rxpbl = <32>;
+		snps,reset-gpio = <&pio 87 GPIO_ACTIVE_LOW>;
+		snps,reset-active-low;
+		tx-delay = <9>;
+		rx-delay = <9>;
+		fine-tune;
+		rmii-rxc;
+		txc-inverse;
+		rxc-inverse;
+	};
-- 
1.7.9.5