rockchip: add fastboot support for rk3036 board

Enable fastboot feature on rk3036, please refer to doc/README.rockchip
for more detailed usage.

Signed-off-by: Ziyuan Xu <xzy.xu@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/rockchip/evb_rk3036/evb_rk3036.c b/board/rockchip/evb_rk3036/evb_rk3036.c
index f5758b1..e5582b4 100644
--- a/board/rockchip/evb_rk3036/evb_rk3036.c
+++ b/board/rockchip/evb_rk3036/evb_rk3036.c
@@ -47,3 +47,49 @@
 	dcache_enable();
 }
 #endif
+
+#if defined(CONFIG_USB_GADGET) && defined(CONFIG_USB_GADGET_DWC2_OTG)
+#include <usb.h>
+#include <usb/dwc2_udc.h>
+
+static struct dwc2_plat_otg_data rk3036_otg_data = {
+	.rx_fifo_sz	= 512,
+	.np_tx_fifo_sz	= 16,
+	.tx_fifo_sz	= 128,
+};
+
+int board_usb_init(int index, enum usb_init_type init)
+{
+	int node;
+	const char *mode;
+	bool matched = false;
+	const void *blob = gd->fdt_blob;
+
+	/* find the usb_otg node */
+	node = fdt_node_offset_by_compatible(blob, -1,
+					"rockchip,rk3288-usb");
+
+	while (node > 0) {
+		mode = fdt_getprop(blob, node, "dr_mode", NULL);
+		if (mode && strcmp(mode, "otg") == 0) {
+			matched = true;
+			break;
+		}
+
+		node = fdt_node_offset_by_compatible(blob, node,
+					"rockchip,rk3288-usb");
+	}
+	if (!matched) {
+		debug("Not found usb_otg device\n");
+		return -ENODEV;
+	}
+	rk3036_otg_data.regs_otg = fdtdec_get_addr(blob, node, "reg");
+
+	return dwc2_udc_probe(&rk3036_otg_data);
+}
+
+int board_usb_cleanup(int index, enum usb_init_type init)
+{
+	return 0;
+}
+#endif