net: ti cpsw ethernet: allow reading phy interface mode from DT

Allow users to specify the phy interface of the CPSW slaves. The new
node parameter is called "phy_if_mode" and is optional. The original
behaviour of the driver is preserved when not given.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Cc: Mugunthan V N <mugunthanvnm@ti.com>
Cc: Vaibhav Hiremath <hvaibhav@ti.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/cpsw.txt

@@ -25,6 +25,8 @@ Required properties:
 - slave_reg_ofs		: Specifies slave register offset
 - sliver_reg_ofs	: Specifies slave sliver register offset
 - phy_id		: Specifies slave phy id
+- phy_if_mode		: Specified slave phy interface mode (optional)
+			  (one of the PHY_INTERFACE_MODE_* as numerical value)
 - mac-address		: Specifies slave MAC address
 
 Optional properties:
@@ -62,6 +64,7 @@ Examples:
 			slave_reg_ofs = <0x208>;
 			sliver_reg_ofs = <0xd80>;
 			phy_id = "davinci_mdio.16:00";
+			phy_if_mode = <6>; /* PHY_INTERFACE_MODE_RGMII */
 			/* Filled in by U-Boot */
 			mac-address = [ 00 00 00 00 00 00 ];
 		};

drivers/net/ethernet/ti/cpsw.c

@@ -855,6 +855,9 @@ static int cpsw_probe_dt(struct cpsw_platform_data *data,
 		}
 		slave_data->sliver_reg_ofs = prop;
 
+		if (!of_property_read_u32(slave_node, "phy_if_mode", &prop))
+			slave_data->phy_if = prop;
+
 		mac_addr = of_get_mac_address(slave_node);
 		if (mac_addr)
 			memcpy(slave_data->mac_addr, mac_addr, ETH_ALEN);