net: stmmac:sti: Add STi SOC glue driver.

STi series SOCs have a glue layer on top of the synopsis gmac IP, this
glue layer needs to be configured before the gmac driver starts using
the IP.

This patch adds a support to this glue layer which is configured via
stmmac setup, init, exit callbacks.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/sti-dwmac.txt

@@ -0,0 +1,58 @@
+STMicroelectronics SoC DWMAC glue layer controller
+
+The device node has following properties.
+
+Required properties:
+ - compatible	: Can be "st,stih415-dwmac", "st,stih416-dwmac" or
+   "st,stid127-dwmac".
+ - reg		: Offset of the glue configuration register map in system
+   configuration regmap pointed by st,syscon property and size.
+
+ - reg-names	: Should be "sti-ethconf".
+
+ - st,syscon	: Should be phandle to system configuration node which
+   encompases this glue registers.
+
+ - st,tx-retime-src: On STi Parts for Giga bit speeds, 125Mhz clocks can be
+   wired up in from different sources. One via TXCLK pin and other via CLK_125
+   pin. This wiring is totally board dependent. However the retiming glue
+   logic should be configured accordingly. Possible values for this property
+
+	   "txclk" - if 125Mhz clock is wired up via txclk line.
+	   "clk_125" - if 125Mhz clock is wired up via clk_125 line.
+
+   This property is only valid for Giga bit setup( GMII, RGMII), and it is
+   un-used for non-giga bit (MII and RMII) setups. Also note that internal
+   clockgen can not generate stable 125Mhz clock.
+
+ - st,ext-phyclk: This boolean property indicates who is generating the clock
+  for tx and rx. This property is only valid for RMII case where the clock can
+  be generated from the MAC or PHY.
+
+ - clock-names: should be "sti-ethclk".
+ - clocks: Should point to ethernet clockgen which can generate phyclk.
+
+
+Example:
+
+ethernet0: dwmac@fe810000 {
+	device_type 	= "network";
+	compatible	= "st,stih416-dwmac", "snps,dwmac", "snps,dwmac-3.710";
+	reg 		= <0xfe810000 0x8000>, <0x8bc 0x4>;
+	reg-names	= "stmmaceth", "sti-ethconf";
+	interrupts	= <0 133 0>, <0 134 0>, <0 135 0>;
+	interrupt-names	= "macirq", "eth_wake_irq", "eth_lpi";
+	phy-mode	= "mii";
+
+	st,syscon	= <&syscfg_rear>;
+
+	snps,pbl 	= <32>;
+	snps,mixed-burst;
+
+	resets		= <&softreset STIH416_ETH0_SOFTRESET>;
+	reset-names	= "stmmaceth";
+	pinctrl-0	= <&pinctrl_mii0>;
+	pinctrl-names 	= "default";
+	clocks		= <&CLK_S_GMAC0_PHY>;
+	clock-names	= "stmmaceth";
+};

drivers/net/ethernet/stmicro/stmmac/Kconfig

@@ -37,6 +37,17 @@ config DWMAC_SUNXI
 	  stmmac device driver. This driver is used for A20/A31
 	  GMAC 	  ethernet controller.
 
+config DWMAC_STI
+	bool "STi GMAC support"
+	depends on STMMAC_PLATFORM && ARCH_STI
+	default y
+	---help---
+	  Support for ethernet controller on STi SOCs.
+
+	  This selects STi SoC glue layer support for the stmmac
+	  device driver. This driver is used on for the STi series
+	  SOCs GMAC ethernet controller.
+
 config STMMAC_PCI
 	bool "STMMAC PCI bus support"
 	depends on STMMAC_ETH && PCI

drivers/net/ethernet/stmicro/stmmac/Makefile

@@ -2,6 +2,7 @@ obj-$(CONFIG_STMMAC_ETH) += stmmac.o
 stmmac-$(CONFIG_STMMAC_PLATFORM) += stmmac_platform.o
 stmmac-$(CONFIG_STMMAC_PCI) += stmmac_pci.o
 stmmac-$(CONFIG_DWMAC_SUNXI) += dwmac-sunxi.o
+stmmac-$(CONFIG_DWMAC_STI) += dwmac-sti.o
 stmmac-objs:= stmmac_main.o stmmac_ethtool.o stmmac_mdio.o ring_mode.o	\
 	      chain_mode.o dwmac_lib.o dwmac1000_core.o  dwmac1000_dma.o \
 	      dwmac100_core.o dwmac100_dma.o enh_desc.o  norm_desc.o \