text: CPSW Port's Interface Mode Selection PHY Tree Bindings
  -----------------------------------------------
  
  TI am335x/am437x/dra7(am5)/dm814x CPSW3G Ethernet Subsystem supports
  two 10/100/1000 Ethernet ports with selectable G/MII, RMII, and RGMII interfaces.
  The interface mode is selected by configuring the MII mode selection register(s)
  (GMII_SEL) in the System Control Module chapter (SCM). GMII_SEL register(s) and
  bit fields placement in SCM are different between SoCs while fields meaning
  is the same.
                                                 +--------------+
          +-------------------------------+      |SCM           |
          |                     CPSW      |      |  +---------+ |
          |        +--------------------------------+gmii_sel | |
          |        |                      |      |  +---------+ |
          |   +----v---+     +--------+   |      +--------------+
          |   |Port 1..<--+-->GMII/MII<------->
          |   |        |  |  |        |   |
          |   +--------+  |  +--------+   |
          |               |               |
          |               |  +--------+   |
          |               |  | RMII   <------->
          |               +-->        |   |
          |               |  +--------+   |
          |               |               |
          |               |  +--------+   |
          |               |  | RGMII  <------->
          |               +-->        |   |
          |                  +--------+   |
          +-------------------------------+
  
  CPSW Port's Interface Mode Selection PHY describes MII interface mode between
  CPSW Port and Ethernet PHY which depends on Eth PHY and board configuration.
  
  CPSW Port's Interface Mode Selection PHY device should defined as child device
  of SCM node (scm_conf) and can be attached to each CPSW port node using standard
  PHY bindings (See phy/phy-bindings.txt).
  
  Required properties:
  - compatible		: Should be "ti,am3352-phy-gmii-sel" for am335x platform
  			  "ti,dra7xx-phy-gmii-sel" for dra7xx/am57xx platform
  			  "ti,am43xx-phy-gmii-sel" for am43xx platform
  			  "ti,dm814-phy-gmii-sel" for dm814x platform
  - reg			: Address and length of the register set for the device
  - #phy-cells		: must be 2.
  			  cell 1 - CPSW port number (starting from 1)
  			  cell 2 - RMII refclk mode
  
  Examples:
  	phy_gmii_sel: phy-gmii-sel {
  		compatible = "ti,am3352-phy-gmii-sel";
  		reg = <0x650 0x4>;
  		#phy-cells = <2>;
  	};
  
  	mac: ethernet@4a100000 {
  		compatible = "ti,am335x-cpsw","ti,cpsw";
  		...
  
  		cpsw_emac0: slave@4a100200 {
  			...
  			phys = <&phy_gmii_sel 1 1>;
  		};
  
  		cpsw_emac1: slave@4a100300 {
  			...
  			phys = <&phy_gmii_sel 2 1>;
  		};
  	};
  