* STMicroelectronics 10/100/1000 Ethernet driver (GMAC)

Required properties:
- compatible: Should be "snps,dwmac-<ip_version>", "snps,dwmac"
	For backwards compatibility: "st,spear600-gmac" is also supported.
- reg: Address and length of the register set for the device
- interrupt-parent: Should be the phandle for the interrupt controller
  that services interrupts for this device
- interrupts: Should contain the STMMAC interrupts
- interrupt-names: Should contain a list of interrupt names corresponding to
	the interrupts in the interrupts property, if available.
	Valid interrupt names are:
  - "macirq" (combined signal for various interrupt events)
  - "eth_wake_irq" (the interrupt to manage the remote wake-up packet detection)
  - "eth_lpi" (the interrupt that occurs when Rx exits the LPI state)
- phy-mode: See ethernet.txt file in the same directory.
- snps,reset-gpio 	gpio number for phy reset.
- snps,reset-active-low boolean flag to indicate if phy reset is active low.
- snps,reset-delays-us  is triplet of delays
	The 1st cell is reset pre-delay in micro seconds.
	The 2nd cell is reset pulse in micro seconds.
	The 3rd cell is reset post-delay in micro seconds.

Optional properties:
- resets: Should contain a phandle to the STMMAC reset signal, if any
- reset-names: Should contain the reset signal name "stmmaceth", if a
	reset phandle is given
- max-frame-size: See ethernet.txt file in the same directory
- clocks: If present, the first clock should be the GMAC main clock and
  the second clock should be peripheral's register interface clock. Further
  clocks may be specified in derived bindings.
- clock-names: One name for each entry in the clocks property, the
  first one should be "stmmaceth" and the second one should be "pclk".
- ptp_ref: this is the PTP reference clock; in case of the PTP is available
  this clock is used for programming the Timestamp Addend Register. If not
  passed then the system clock will be used and this is fine on some
  platforms.
- tx-fifo-depth: See ethernet.txt file in the same directory
- rx-fifo-depth: See ethernet.txt file in the same directory
- snps,pbl		Programmable Burst Length (tx and rx)
- snps,txpbl		Tx Programmable Burst Length. Only for GMAC and newer.
			If set, DMA tx will use this value rather than snps,pbl.
- snps,rxpbl		Rx Programmable Burst Length. Only for GMAC and newer.
			If set, DMA rx will use this value rather than snps,pbl.
- snps,no-pbl-x8	Don't multiply the pbl/txpbl/rxpbl values by 8.
			For core rev < 3.50, don't multiply the values by 4.
- snps,aal		Address-Aligned Beats
- snps,fixed-burst	Program the DMA to use the fixed burst mode
- snps,mixed-burst	Program the DMA to use the mixed burst mode
- snps,force_thresh_dma_mode	Force DMA to use the threshold mode for
				both tx and rx
- snps,force_sf_dma_mode	Force DMA to use the Store and Forward
				mode for both tx and rx. This flag is
				ignored if force_thresh_dma_mode is set.
- snps,en-tx-lpi-clockgating	Enable gating of the MAC TX clock during
				TX low-power mode
- snps,multicast-filter-bins:	Number of multicast filter hash bins
				supported by this device instance
- snps,perfect-filter-entries:	Number of perfect filter entries supported
				by this device instance
- snps,ps-speed: port selection speed that can be passed to the core when
		 PCS is supported. For example, this is used in case of SGMII
		 and MAC2MAC connection.
- snps,tso: this enables the TSO feature otherwise it will be managed by
		 MAC HW capability register. Only for GMAC4 and newer.
- AXI BUS Mode parameters: below the list of all the parameters to program the
			   AXI register inside the DMA module:
	- snps,lpi_en: enable Low Power Interface
	- snps,xit_frm: unlock on WoL
	- snps,wr_osr_lmt: max write outstanding req. limit
	- snps,rd_osr_lmt: max read outstanding req. limit
	- snps,kbbe: do not cross 1KiB boundary.
	- snps,blen: this is a vector of supported burst length.
	- snps,fb: fixed-burst
	- snps,mb: mixed-burst
	- snps,rb: rebuild INCRx Burst
- mdio: with compatible = "snps,dwmac-mdio", create and register mdio bus.
- Multiple RX Queues parameters: below the list of all the parameters to
				 configure the multiple RX queues:
	- snps,rx-queues-to-use: number of RX queues to be used in the driver
	- Choose one of these RX scheduling algorithms:
		- snps,rx-sched-sp: Strict priority
		- snps,rx-sched-wsp: Weighted Strict priority
	- For each RX queue
		- Choose one of these modes:
			- snps,dcb-algorithm: Queue to be enabled as DCB
			- snps,avb-algorithm: Queue to be enabled as AVB
		- snps,map-to-dma-channel: Channel to map
		- Specifiy specific packet routing:
			- snps,route-avcp: AV Untagged Control packets
			- snps,route-ptp: PTP Packets
			- snps,route-dcbcp: DCB Control Packets
			- snps,route-up: Untagged Packets
			- snps,route-multi-broad: Multicast & Broadcast Packets
		- snps,priority: RX queue priority (Range: 0x0 to 0xF)
- Multiple TX Queues parameters: below the list of all the parameters to
				 configure the multiple TX queues:
	- snps,tx-queues-to-use: number of TX queues to be used in the driver
	- Choose one of these TX scheduling algorithms:
		- snps,tx-sched-wrr: Weighted Round Robin
		- snps,tx-sched-wfq: Weighted Fair Queuing
		- snps,tx-sched-dwrr: Deficit Weighted Round Robin
		- snps,tx-sched-sp: Strict priority
	- For each TX queue
		- snps,weight: TX queue weight (if using a DCB weight algorithm)
		- Choose one of these modes:
			- snps,dcb-algorithm: TX queue will be working in DCB
			- snps,avb-algorithm: TX queue will be working in AVB
			  [Attention] Queue 0 is reserved for legacy traffic
			  and so no AVB is available in this queue.
		- Configure Credit Base Shaper (if AVB Mode selected):
			- snps,send_slope: enable Low Power Interface
			- snps,idle_slope: unlock on WoL
			- snps,high_credit: max write outstanding req. limit
			- snps,low_credit: max read outstanding req. limit
		- snps,priority: TX queue priority (Range: 0x0 to 0xF)
Examples:

	stmmac_axi_setup: stmmac-axi-config {
		snps,wr_osr_lmt = <0xf>;
		snps,rd_osr_lmt = <0xf>;
		snps,blen = <256 128 64 32 0 0 0>;
	};

	mtl_rx_setup: rx-queues-config {
		snps,rx-queues-to-use = <1>;
		snps,rx-sched-sp;
		queue0 {
			snps,dcb-algorithm;
			snps,map-to-dma-channel = <0x0>;
			snps,priority = <0x0>;
		};
	};

	mtl_tx_setup: tx-queues-config {
		snps,tx-queues-to-use = <2>;
		snps,tx-sched-wrr;
		queue0 {
			snps,weight = <0x10>;
			snps,dcb-algorithm;
			snps,priority = <0x0>;
		};

		queue1 {
			snps,avb-algorithm;
			snps,send_slope = <0x1000>;
			snps,idle_slope = <0x1000>;
			snps,high_credit = <0x3E800>;
			snps,low_credit = <0xFFC18000>;
			snps,priority = <0x1>;
		};
	};

	gmac0: ethernet@e0800000 {
		compatible = "st,spear600-gmac";
		reg = <0xe0800000 0x8000>;
		interrupt-parent = <&vic1>;
		interrupts = <24 23 22>;
		interrupt-names = "macirq", "eth_wake_irq", "eth_lpi";
		mac-address = [000000000000]; /* Filled in by U-Boot */
		max-frame-size = <3800>;
		phy-mode = "gmii";
		snps,multicast-filter-bins = <256>;
		snps,perfect-filter-entries = <128>;
		rx-fifo-depth = <16384>;
		tx-fifo-depth = <16384>;
		clocks = <&clock>;
		clock-names = "stmmaceth";
		snps,axi-config = <&stmmac_axi_setup>;
		mdio0 {
			#address-cells = <1>;
			#size-cells = <0>;
			compatible = "snps,dwmac-mdio";
			phy1: ethernet-phy@0 {
			};
		};
		snps,mtl-rx-config = <&mtl_rx_setup>;
		snps,mtl-tx-config = <&mtl_tx_setup>;
	};