Dear Rob,

Thanks for your comments.

On Mon, 2018-11-12 at 10:22 -0600, Rob Herring wrote:

On Mon, Oct 29, 2018 at 11:04:54AM +0800, Biao Huang wrote:

quoted

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

Signed-off-by: Biao Huang <redacted>
---
 .../devicetree/bindings/net/mediatek-dwmac.txt     |   49 ++++++++++++++++++++
 1 file changed, 49 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..8baf0e4
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/mediatek-dwmac.txt

@@ -0,0 +1,49 @@
+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

Clocks should represent the physical clocks connected to a block. Parent 
clocks are not in that category.

There are two categories of physical clocks related to MAC.
1. axi/apb/ptp_top, these clks are from clk gates, so only on/off is
needed.
2. mac_ext/ptp_ref, these clks are from mux. If different source is
selected, the clk frequecy will be different. So it's necessary to set a
proper parent for them, i.e. mac_parent/ptp_parent.

How should I handle parent clocks if not defined here? Any examples I
can refer to?

quoted

+- mac-address: See ethernet.txt in the same directory
+- phy-mode: See ethernet.txt in the same directory
+
+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;
+	};
-- 
1.7.9.5

Best Regards!
Biao