sunxi: add gmac Ethernet support

Add support for the GMAC Ethernet controller on Allwinner A20 (sun7i)
processors. Enable for the Cubietruck.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Jens Kuske <jenskuske@gmail.com>
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Reviewed-by: Marek Vasut <marex@denx.de>
Reviewed-by: Tom Rini <trini@ti.com>
diff --git a/board/sunxi/gmac.c b/board/sunxi/gmac.c
new file mode 100644
index 0000000..e48328d
--- /dev/null
+++ b/board/sunxi/gmac.c
@@ -0,0 +1,32 @@
+#include <common.h>
+#include <netdev.h>
+#include <miiphy.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/gpio.h>
+
+int sunxi_gmac_initialize(bd_t *bis)
+{
+	int pin;
+	struct sunxi_ccm_reg *const ccm =
+		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+
+	/* Set up clock gating */
+	setbits_le32(&ccm->ahb_gate1, 0x1 << AHB_GATE_OFFSET_GMAC);
+
+	/* Set MII clock */
+	setbits_le32(&ccm->gmac_clk_cfg, CCM_GMAC_CTRL_TX_CLK_SRC_INT_RGMII |
+		CCM_GMAC_CTRL_GPIT_RGMII);
+
+	/* Configure pin mux settings for GMAC */
+	for (pin = SUNXI_GPA(0); pin <= SUNXI_GPA(16); pin++) {
+		/* skip unused pins in RGMII mode */
+		if (pin == SUNXI_GPA(9) || pin == SUNXI_GPA(14))
+			continue;
+		sunxi_gpio_set_cfgpin(pin, SUN7I_GPA0_GMAC);
+		sunxi_gpio_set_drv(pin, 3);
+	}
+
+	return designware_initialize(SUNXI_GMAC_BASE, PHY_INTERFACE_MODE_RGMII);
+}